ascorbic-acid and 1-1-diphenyl-2-picrylhydrazyl

The study of antioxidants and their implications in various fields, from food engineering to medicine and pharmacy, is of major interest to the scientific community. The present paper is a critical presentation of the most important tests used to determine the antioxidant activity, detection mechanism, applicability, advantages and disadvantages of these methods. Out of the tests based on the transfer of a hydrogen atom, the following were presented: the Oxygen Radical Absorption Capacity (ORAC) test, the Hydroxyl Radical Antioxidant Capacity (HORAC) test, the Total Peroxyl Radical Trapping Antioxidant Parameter (TRAP) test, and the Total Oxyradical Scavenging Capacity (TOSC) test. The tests based on the transfer of one electron include the Cupric Reducing Antioxidant Power (CUPRAC) test, the Ferric Reducing Antioxidant Power (FRAP) test, the Folin-Ciocalteu test. Mixed tests, including the transfer of both a hydrogen atom and an electron, include the 2,2'-Azinobis-(3-ethylbenzothiazoline-6-sulfonic acid (ABTS) test, and the [2,2-di(4-tert-octylphenyl)-1-picrylhydrazyl] (DPPH) test. All these assays are based on chemical reactions and assessing the kinetics or reaching the equilibrium state relies on spectrophotometry, presupposing the occurrence of characteristic colours or the discolouration of the solutions to be analysed, which are processes monitored by specific wavelength adsorption. These assays were successfully applied in antioxidant analysis or the determination of the antioxidant capacity of complex samples. As a complementary method in such studies, one may use methods based on electrochemical (bio)sensors, requiring stages of calibration and validation. The use of chemical methods together with electrochemical methods may result in clarification of the operating mechanisms and kinetics of the processes involving several antioxidants.

Topics: Animals; Antioxidants; Ascorbic Acid; Benzothiazoles; Biological Assay; Biphenyl Compounds; Electrochemical Techniques; Free Radical Scavengers; Humans; Hydrogen; Hydroxyl Radical; Kinetics; Oxygen; Phenols; Picrates; Reactive Oxygen Species; Sulfonic Acids; Superoxide Dismutase

Chitosan is an important biopolymer produced from the deacetylation of several seas and insect crusts. Due to its environmental fate and biological biocompatibility, it can be used in several biological and environmental applications. In this review, the potential application of chitosan biopolymer was reviewed due to it is considered an environmental, sustainable, and biologically safe plate form for producing several antioxidants. The different antioxidants fabricated from chitosan biopolymer- an active substrate- and the functional role of the diverse groups, either in chitosan backbone or in the coupled species with chitosan, were reviewed. Different antioxidant types were described, reviewed, and compared with the most famous and traditional antioxidants, such as ascorbic acid, citric acid, and gallic acid. Additionally, the different methods and techniques used in determining the antioxidative tendencies of the antioxidants were extensively described and reviewed.

Topics: Animals; Antioxidants; Ascorbic Acid; Biopolymers; Biphenyl Compounds; Chelating Agents; Chitosan; Citric Acid; Free Radical Scavengers; Gallic Acid; Hydroxyl Radical; Metals; Peroxynitrous Acid; Phenols; Picrates; Polyphenols; Spectroscopy, Fourier Transform Infrared

Ascorbic acid supplementation has been recommended to circumvent resistance to erythropoietin, which sometimes occurs in iron-overloaded uremic patients. In considering the pro-oxidant effect of ascorbic acid, the authors hypothesize that adjuvant therapy with larger doses of ascorbic acid in hemodialysis patients with iron overload may raise the risk of increasing free radical generation. The oxidative stress of intravenous ascorbic acid supplementation in hemodialysis patients was evaluated in this study.. Six healthy subjects and 29 hemodialysis patients were enrolled. Chemical scavenging activity of various compounds was measured by in vitro 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay. Free radical generation was determined in vitro by lucigenin-enhanced chemiluminescence (LucCL) assay on blood samples. Blood biochemistries were also measured simultaneously in hemodialysis patients 1 minute before and 5 minutes later in the presence or absence of intravenous injection of 300 mg ascorbic acid.. Ascorbic acid presented a strong antioxidant effect in DPPH chemical reaction. On the contrary, it exerted pro-oxidant effect when mixed with plasma or whole blood of healthy subjects and hemodialysis patients. The pro-oxidant effect of ascorbic acid detected by LucCL was attenuated by various iron chelators and superoxide dismutase. In hemodialysis patients, the changes of LucCL intensity were significantly higher in the ascorbic acid-treated group than those in the control group (1261.0 +/- 401.9 v 77.4 +/- 62.5 relative light unit [RLU]; P < 0.05). Adjuvant ascorbic acid therapy resulted in significantly higher LucCL intensity in hemodialysis patients with ferritin > or =600 ng/mL (1,348.2 pmol/L) than those with ferritin less than 600 ng/mL (2,296.0 +/- 763.8 v 414.3 +/- 88.0 RLU; P<0.05). The changes of LucCL intensity were positively correlated with serum ferritin level (R2=0.8673; P<0.05). However, there was no significant correlation between the responses of LucCL intensity to ascorbic acid administration and transferrin saturation (R2=0.195; P=0.0665).. Persons with excess ascorbic acid supplement in the blood or plasma generate iron-chelator-suppressible chemiluminescents suggestive of free radical formation. Whether the findings occur in vivo or that the free radicals generated in vitro lead to toxicity in patients is not known from this study. These results suggest that either lower parenteral dose or lower infusion rate of ascorbic acid may be more appropriate for adjuvant therapy in iron-overloaded uremic patients.

Topics: Aged; Antioxidants; Ascorbic Acid; Biphenyl Compounds; Female; Ferritins; Free Radical Scavengers; Free Radicals; Humans; Hydrazines; In Vitro Techniques; Injections, Intravenous; Iron; Iron Overload; Kidney Failure, Chronic; Luminescent Measurements; Male; Middle Aged; Oxidative Stress; Picrates; Renal Dialysis

Alzheimer's disease (AD) possesses a complex pathogenetic mechanism. Nowadays, multitarget agents are considered to have potential in effectively treating AD via triggering molecules in functionally complementary pathways at the same time. Here, based on the screening (∼1400 compounds) against neuroinflammation, an imidazolylacetophenone oxime ether (IOE) was discovered as a novel hit. In order to obtain SARs, a series of imidazolylacetophenone oxime derivatives were constructed, and their C=N bonds were confirmed as the Z configuration by single crystals. These derivatives exhibited potential multifunctional neuroprotective effects including anti-neuroinflammatory, antioxidative damage, metal-chelating, inhibition of acetylcholinesterase (AChE) properties. Among these derivatives, compound 12i displayed the most potent inhibitory activity against nitric oxide (NO) production with EC

Topics: Acetophenones; Acetylcholinesterase; Animals; Biphenyl Compounds; Cell Line; Cyclooxygenase 2; Dose-Response Relationship, Drug; Drug Discovery; Electrophorus; Enzyme Inhibitors; Humans; Imidazoles; Lipopolysaccharides; Mice; Molecular Structure; Neuroprotective Agents; Nitric Oxide; Oximes; Picrates; Rats; Structure-Activity Relationship

Harnessing the antioxidant cellular machinery has sparked considerable interest as an efficient anticancer strategy. Activating Nrf2, the master switch of the cellular redox system, suppresses ROS, alleviates oxidative stress, and halts cancer progression. 1,2,4-oxadiazoles are iconic direct Nrf2 activators that disrupt Nrf2 interaction with its endogenous repressor Keap1. This study introduces rationally designed 1,2,4-oxadiazole derivatives that inhibit other Nrf2 suppressors (TrxR1, IKKα, and NF-kB) thus enhancing Nrf2 activation for preventing oxidative stress and carcinogenesis. Preliminary screening showed that the phenolic oxadiazoles 11, 15, and 19 were comparable to ascorbic acid (ROS scavenging) and EDTA (iron chelation), and superior to doxorubicin against HepG-2, MDA-MB231, and Caco-2 cells. They suppressed ROS by 3 folds and activated Nrf2 by 2 folds in HepG-2 cells. Mechanistically, they inhibited TrxR1 (IC

Topics: Antineoplastic Agents; Antioxidants; Biphenyl Compounds; Cell Proliferation; Cell Survival; Cells, Cultured; Dose-Response Relationship, Drug; Drug Screening Assays, Antitumor; Humans; Molecular Structure; Oxadiazoles; Picrates; Structure-Activity Relationship

A modest, competent and green synthetic procedure for novel coumarinyl-1,3,4-oxadiazolyl-2-mercaptobenzoxazoles 8i-t has been reported. Analysis of the docked (PDB ID: 5IKR; A-Chain) poses of the compounds illustrated that they adopt identical conformations to the extremely selective COX-2 inhibitor. The biological outcomes as well as computational study suggested that the compounds originated to have elevated resemblance towards COX-2 enzyme than COX-1. The compounds 8i, 8l, 8q, 8r, 8s and 8t emerged as most potent and selective COX-2 inhibitors in contrast with Mefenamic acid. The selectivity index of 8l, 8n and 8r was respectively found to be 33.95, 20.25 and 24.98 which manifested their high selectivity against COX-2. Interestingly, the compounds which were active as COX-2 inhibitors were also active as antioxidant agents.

Topics: Antioxidants; Biphenyl Compounds; Cyclooxygenase 2; Cyclooxygenase 2 Inhibitors; Green Chemistry Technology; Humans; Microwaves; Models, Molecular; Molecular Structure; Oxadiazoles; Picrates

Piperine, as the most abundant alkaloid in pepper, gained a lot of attention for possible antioxidant and therapeutic properties. Electrochemical techniques were applied to widely evaluate the redox behavior of piperine by comparison to that of well-known antioxidants: ascorbic acid, protocatechuic acid, syringic acid, tyrosine and capsaicin used as controls. Also, electrochemistry was involved in an innovative way to investigate the potential antioxidant properties of piperine combined with different in vitro peroxidation and reducing assays: (i) 1,1-diphenyl-2-picryl-hydrazyl free radical (DPPH) scavenging; (ii) 2,2,6,6-tetramethylpiperidinyl-1-oxy (TEMPO) scavenging; (iii) ferric ions (Fe

Topics: Alkaloids; Antioxidants; Ascorbic Acid; Benzodioxoles; Biphenyl Compounds; Cyclic N-Oxides; Electrochemical Techniques; Free Radical Scavengers; Free Radicals; Hydrogen Peroxide; Iron; Oxidation-Reduction; Picrates; Piperidines; Polyunsaturated Alkamides

Overexpression of collagenase, elastase, and tyrosinase is caused by external factors such as ultraviolet (UV) radiation and stress, resulting in wrinkle formation and freckles through the loss of skin elasticity and skin pigmentation. In this study, we developed novel carbon quantum dots (CQDs) with antioxidant and anti-aging properties using tannic acid as a carbon source through a simple microwave-assisted pyrolysis method. The synthesized tannic acid-derived CQDs (T-CQDs) showed bright blue fluorescence (QY = 28.2 ± 4.0%), exhibiting maximum emission at 430 nm under 350 nm excitation. Even though small amount of the T-CQDs (3

Topics: Antioxidants; Ascorbic Acid; Biphenyl Compounds; Carbon; Cell Line, Tumor; Cell Survival; Collagenases; Enzyme Inhibitors; Ethylenediamines; Geroscience; Humans; Melanocytes; Microwaves; Monophenol Monooxygenase; Pancreatic Elastase; Picrates; Quantum Dots; Quercetin; Tannins

A series of novel 2, 5-disubstituted 1, 3, 4-Oxadiazole derivatives as a potential anti-inflammatory, and anti-oxidant agent were synthesized via cyclisation. Hydrazide molecule treated with substituted acids in the presence of phosphorus oxychloride (POCl

Topics: Anti-Inflammatory Agents, Non-Steroidal; Antioxidants; Biphenyl Compounds; Cyclooxygenase 2; Cyclooxygenase 2 Inhibitors; Dose-Response Relationship, Drug; Humans; Molecular Docking Simulation; Molecular Structure; Oxadiazoles; Picrates; Structure-Activity Relationship

Topics: Animals; Anti-Inflammatory Agents; Antineoplastic Agents, Phytogenic; Antioxidants; Biphenyl Compounds; Cell Line, Tumor; Cell Proliferation; Cell Survival; Citrus; Dose-Response Relationship, Drug; Drug Screening Assays, Antitumor; Humans; Interleukin-6; Lanosterol; Mice; Molecular Conformation; Picrates; Plant Extracts; Plant Leaves; RAW 264.7 Cells; Structure-Activity Relationship

Quarantine treatment enables export of mango fruits to parts of the world that enforce quarantine against fruit fly. Chilling injuries (CI) are prevalent in the mango fruits stored at temperatures lower than 12°C during cold-quarantine. So, this research examined the potentially enable of cold-shock treatment and integrated of edible coating with packing in (EPE) foam net to enhance the resistance of Naomi mango fruits during cold export.. The effect of cold quarantine was studied on fruit quality of 'Naomi' mango for 2016 and 2017 seasons. In this respect, mango fruits were coated with sodium alginate at 3%, semperfreshTM at 1% and packed in (EPE) foam net to reduce CI during cold quarantine. The treated fruits were stored for 4 h at 0°C, then transferred to 20°C for 20 h (cold-shock treatment) prior to store at 2±1°C and 90-95% RH for 15 days (quarantine treatment). While, the control fruit were directly stored at 2±1°C and 90-95% RH for 15 days. Thereafter, all fruits were stored at 20±2°C for and 70-75% RH for 7 days as shelf life period to simulate a marketing period.. All applied treatments significantly reduced fruits weight loss (%), respiration rate, retard the loss of soluble solid (%) titratable acidity (%), have a good potential in maintaining firmness (lb inch-2), skin color h°, vitamin C, total phenol, flavonoids content, membrane stability index (MSI %), high rate of antioxidant capacity and retard the loss of shelf-life of fruits than the control.. It was concluded that edible coatings used semperfreshTM at 1% with (EPE) foam net packing have a good potential in controlling postharvest chilling injury and maintaining the fruit quality being the most effective treatment on all parameters tested. It could potentially enable the export mango fruits to all quarantine-enforcing countries.

Topics: Antioxidants; Ascorbic Acid; Biphenyl Compounds; Cold Temperature; Cold-Shock Response; Flavonoids; Food Preservation; Food Storage; Free Radical Scavengers; Fruit; Gases; Mangifera; Methanol; Phenols; Picrates; Plant Extracts; Superoxide Dismutase; Temperature

In the present study, a new series of

Topics: Antioxidants; Aromatase; Aromatase Inhibitors; Ascorbic Acid; Biphenyl Compounds; Computer Simulation; Humans; Hydrogen Peroxide; In Vitro Techniques; Molecular Docking Simulation; Organophosphonates; Picrates; Uracil

Peptic lesions usually develop when there is an imbalance between aggressive drivers and gastro-protective mediators that guard the lining of the gastrointestinal tract. The most crucial of these mediators are antioxidants, whose loss may predispose to oxidative stress, which is believed to be the main aggravator of several diseases including peptic ulcer. Proton pump inhibitors (PPIs) are drugs that are highly effective and widely used for therapeutic management of peptic disorders through inhibition of gastric acid secretion. In spite of this, oxidative damage may continue to be a major issue that can predispose to future lesions.. The present study is designed to explore the possible antioxidant capability of different PPIs, including omeprazole, esomeprazole, lansoprazole, pantoprazole, and rabeprazole, in an aim to suggest an agent that, in addition to its acid-suppression properties, can provide antioxidant profit.. The antioxidant activity of different PPIs was evaluated calorimetrically to test the ability of each drug to quench oxygen free radical, using the well-known stable free radical α,α-diphenyl-β-picrylhydrazyl (DPPH), and compared to ascorbic acid (AA; vitamin C). The measurements were performed using a spectrophotometer at 517 nm.. All the studied drugs reduced DPPH, but to different extents. However, omeprazole and esomeprazole showed the highest ability to scavenge free radicals (50% inhibitory concentrations [IC50s] of the percentage for free radical scavenging activity are 18.7 ± 5.7 and 18.7 ± 5.7, respectively, and the AA equivalents are 83,772 ± 11,887 and 81,732 ± 8,523 mg AA/100 g, respectively). Conversely, lansoprazole, pantoprazole, and rabeprazole might be having no role in this story (IC50s of the percentage for free radical scavenging activity are 49.3 ± 3.1, 49 ± 9.4, and 40.7 ± 7.2, respectively, and the AA equivalents are 30,458 ± 3,884, 32,222 ± 10,377, and 37,876 ± 8,816 mg AA/100 g, respectively).. Thus, omeprazole and esomeprazole may confer a significant dual action in gastrointestinal protection by providing potent antioxidant properties in addition to their major role as acid-suppression agents. However, further studies are essential to elucidate the mechanism behind the difference between the drugs of the same class.

Topics: Antioxidants; Ascorbic Acid; Biphenyl Compounds; Esomeprazole; Free Radicals; In Vitro Techniques; Inhibitory Concentration 50; Lansoprazole; Omeprazole; Pantoprazole; Picrates; Proton Pump Inhibitors; Rabeprazole; Spectrophotometry

The use of higher plants for the production of plant growth biostimulants is receiving increased attention among scientists, farmers, investors, consumers and regulators. The aim of the present study was to examine the possibility of converting plants commonly occurring in Europe (St. John's wort, giant goldenrod, common dandelion, red clover, nettle, valerian) into valuable and easy to use bio-products. The biostimulating activity of botanical extracts and their effect on the chemical composition of celeriac were identified. Plant-based extracts, obtained by ultrasound-assisted extraction and mechanical homogenisation, were tested in field trials. It was found that the obtained formulations increased the total yield of leaves rosettes and roots, the dry weight of leaves rosettes and roots, the content of chlorophyll

Topics: Antioxidants; Apium; Ascorbic Acid; Benzothiazoles; Biphenyl Compounds; Carotenoids; Chemistry, Pharmaceutical; Chlorophyll; Chlorophyll A; Europe; Fatty Acids; Horticulture; Nitrates; Photosynthesis; Picrates; Pigmentation; Plant Extracts; Plant Leaves; Plant Roots; Polyphenols; Sulfonic Acids; Ultrasonics

A series of thirteen new aryl/hetarylbichalcophene-5-carboxamidines was prepared and screened for an in vitro anti-proliferative activity against sixty cancer cell lines. The tested monocationic bichalcophenes displayed promising potent anticancer activity against most cancer cell lines with GI

Topics: Antineoplastic Agents; Antioxidants; Apoptosis; Biphenyl Compounds; Cell Line; Cell Proliferation; Dose-Response Relationship, Drug; Drug Screening Assays, Antitumor; Humans; Molecular Structure; Picrates; Structure-Activity Relationship

Nineteen organoselenides were synthesized and tested for their intrinsic cytotoxicity in hepatocellular carcinoma (HepG2) and breast adenocarcinoma (MCF-7) cell lines and their corresponding selective cytotoxicity (SI) was estimated using normal lung fibroblast (WI-38) cells. Most of the organic selenides exhibited good anticancer activity, and this was more pronounced in HepG2 cells. Interestingly, the naphthoquinone- (5), thiazol- (12), and the azo-based (13) organic selenides demonstrated promising SI (up to 76). Furthermore, the amine 4c, naphthoquinone 5, and azo-based 13 and 15 organic selenides were able to down-regulate the expression of Bcl-2 and up-regulate the expression levels of IL-2, IL-6 and CD40 in HepG2 cells compared to untreated cells. Moreover, most of the synthesized candidates manifested good free radical-scavenging and GPx-like activities comparable to vitamin C and ebselen. The obtained results suggested that some of the presented organoselenium candidates have promising anti-HepG2 and antioxidant activities.

Topics: Antineoplastic Agents; Antioxidants; Biphenyl Compounds; Breast Neoplasms; Carcinoma, Hepatocellular; Cell Line; Cell Proliferation; Dose-Response Relationship, Drug; Drug Screening Assays, Antitumor; Female; Hep G2 Cells; Humans; Liver Neoplasms; MCF-7 Cells; Molecular Structure; Organoselenium Compounds; Picrates; Structure-Activity Relationship

Targeting of tyrosinase has proven to be the best means of identifying safe, efficacious, and potent tyrosinase inhibitors for whitening skin. We designed and synthesized ten NAB (N-(acryloyl)benzamide) derivatives (1a-1j) using the Horner-Wadsworth-Emmons olefination of diethyl (2-benzamido-2-oxoethyl)phosphonate and appropriate benzaldehydes. A mushroom tyrosinase inhibitory assay showed compounds 1a (36.71 ± 2.14% inhibition) and 1j (25.99 ± 2.77% inhibition) inhibited tyrosinase more than the other eight NAB derivatives and kojic acid (21.56 ± 2.93% inhibition), and docking studies indicated 1a (-6.9 kcal/mole) and 1j (-7.5 kcal/mole) had stronger binding affinities for tyrosinase than kojic acid (-5.7 kcal/mole). At a concentration of 25 μM, 1a and 1j were nontoxic in B16F10 melanoma cells and exhibited stronger tyrosinase inhibition (59.70% and 76.77%, respectively) than kojic acid (50.30% inhibition) or arbutin (41.78% inhibition at 400 μM). Similarly, in B16F10 melanoma cells, compounds 1a and 1j at 25 μM decreased total melanin content by 47.97% and 61.77%, respectively (kojic acid; 38.98%). Similarities between inhibitions of tyrosinase activity and melanin contents suggested the anti-melanogenic effects of 1a and 1j were due to tyrosinase inhibition. The excellent DPPH scavenging activity of 1j suggests it might enhance in vivo effect on melanin contents. The study suggests compound 1j offers a potential starting point for the development of safe, potent tyrosinase inhibitors.

Topics: Agaricales; Animals; Benzamides; Biphenyl Compounds; Cell Survival; Dose-Response Relationship, Drug; Enzyme Inhibitors; Free Radical Scavengers; Melanins; Mice; Molecular Structure; Monophenol Monooxygenase; Picrates; Structure-Activity Relationship; Tumor Cells, Cultured

Naturally produced polyhydroxyalkanoates (PHAs) biopolymers have limited medical applications due to their brittle and hydrophobic nature. In this study poly(3-hydroxybutyrate-co-3-hydroxyvalerate) P(3HB-co-3HV) copolymer was produced using engineered Escherichia coli YJ101, and further functionalized with ascorbic acid using Candida antarctica lipase B mediated esterification. Copolymer P(3HB-co-3HV)-ascorbic acid showed lower degree of crystallinity (9.96%), higher thermal degradation temperature (294.97 °C) and hydrophilicity (68°) as compared to P(3HB-co-3HV). Further, P(3HB-co-3HV)-ascorbic acid biomaterial showed 14% scavenging effect on 1,1-diphenyl-2-picryl-hydrazyl (DPPH), and 1.6 fold increase in biodegradability as compared to P(3HB-co-3HV). Improvement of PHAs polymer properties by adding functional groups could be a good approach to increase their biodegradability, economic value and important applications in the medical field.

Topics: Antioxidants; Ascorbic Acid; Biocompatible Materials; Biodegradation, Environmental; Biphenyl Compounds; Escherichia coli; Fungal Proteins; Lipase; Picrates; Polyesters; Polyhydroxyalkanoates; Polymers

The aim a present study was developed methylcellulose (MC) active edible films with extracts of green apple skin, as model systems of edible coating. Active edible films were developed by incorporation of ethanolic extract of freeze-dried apple skin (EEFD) and aqueous extract of apple skin (AES) at 10, 20 and 25% (v/v) concentrations. Analysis of thermal, mechanical and functional properties was carried out. Results showed that incorporation of green apple skin extracts into MC films contribute to total phenolic content and antioxidant properties. Addition of green apple skin extracts generated shifts toward lower glass transition temperature values regarding MC films without extracts. A lower tensile strength and increased elongation at break in MC-AES films were observed. Mechanical properties of MC-EEFD films were less affected by the increase in extract concentration due to absence of the plasticizing effect of sugars present in AES. The methylcellulose films are important for actives edibles coatings with applications in the food industry.

Topics: Antioxidants; Ascorbic Acid; Biphenyl Compounds; Coated Materials, Biocompatible; Ethanol; Food Packaging; Freeze Drying; Fruit; Humans; Malus; Methylcellulose; Phase Transition; Picrates; Plant Extracts; Polyphenols; Solvents; Tensile Strength

A series of novel 1-(5-chloro-2-hydroxyphenyl)-5-oxopyrrolidine-3-carboxylic acid derivatives containing chloro, hydroxyl, isopropyl, nitro, nitroso, and amino substituents at benzene ring and 1-(5-chloro-2-hydroxyphenyl)-5-oxopyrrolidine-3-carbohydrazide derivatives bearing heterocyclic moieties were synthesized. Antioxidant activity of the synthesized compounds was screened by DPPH radical scavenging method and reducing power assay. A number of compounds were identified as potent antioxidants. Antioxidant activity of 1-(5-chloro-2-hydroxyphenyl)-4-(5-thioxo-4,5-dihydro-1,3,4-oxadiazol-2-yl)pyrrolidin-2-one has been tested to be 1.5 times higher than that of a well-known antioxidant ascorbic acid. 1-(5-Chloro-2-hydroxyphenyl)-4-(4-methyl-5-thioxo-4,5-dihydro-1

Topics: Antioxidants; Ascorbic Acid; Azoles; Biphenyl Compounds; Carboxylic Acids; Picrates; Structure-Activity Relationship; X-Ray Diffraction

Barley sprouts and wheat sprouts have received much interest as functional foods in many countries. In this study, the effects of heat processing and extraction temperature on the bioactive components and antioxidative properties were examined in barley and wheat sprout teas. Both barley and wheat sprout teas were processed with two different methods (steaming or pan-roasting). Crude protein was increased, and moisture content was the lowest, in the roasted barley and wheat sprout teas. Total phenolics content and flavonoid contents were significantly higher in the roasted teas than in the steamed teas. Vitamin C content was the highest after an extraction temperature of 55 °C (24.05 mg/mL) in the roasted wheat sprout tea. Both roasted barley and wheat sprout teas exhibited the most antioxidative effects in vitro, demonstrated by 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical-scavenging and nitrite-scavenging activities. Therefore, the roasting method can be considered an appropriate technique for the production of barley and wheat sprout teas. PRACTICAL APPLICATION: Barley and wheat sprouts have received much attention in recent years as functional food materials in many countries and can be consumed as a form of tea. Heat processing methods such as steaming and roasting were applied and compared to increase the bioactive components and antioxidative activity in barley and wheat sprout teas. We found that roasting showed higher bioactive components and antioxidative activity than steaming in both barley and wheat sprout teas. In addition, wheat sprouts tea showed better bioactive components and antioxidative activity compared with the barley sprout tea.

Topics: Antioxidants; Ascorbic Acid; Beverages; Biphenyl Compounds; Cooking; Flavonoids; Hordeum; Hot Temperature; Humans; Phenols; Picrates; Plant Extracts; Seedlings; Tea; Triticum

Background In this study, the hematological and antioxidant potential as well as the osmotic fragility effects of a Nigerian polyherbal formulation were evaluated. Materials and methods A total of 40 fats were divided into four groups of 10 rats each. Group 1 served as the control group, and the rest were assigned increasing daily oral administration of the extract for 28 days. At the end of treatment, blood was collected for hematological and osmotic fragility studies. The free radical scavenging effect of the extract was investigated via different in vitro models as well. Results Results showed that the nitric oxide scavenging and 2,2-diphenyl-1-picrylhydrazyl (DPPH) activities of the extract were significant (p < 0.05) and compared favorably with that of vitamin C. At 200 and 400 μg/mL, the nitric oxide scavenging activities for Ajumbise Polyherbal Extract (APE) were 60.71 ± 0.25% and 59.49 ± 0.98%, respectively, whereas for the same concentrations of vitamin C, 74.60 ± 0.25% and 85.24 ± 0.14 scavenging activities were obtained. The (DPPH) activity at 100 μg/mL was 81.24 ± 0.02% for the extract and 96.22 ± 0.18% for vitamin C. However, at all concentrations, the extract had significantly lower Ferric Reducing Antioxidant Power (FRAP) activity than vitamin C. Red blood cell counts (RBCC), hemoglobin and packed cell volume values (PCV) were significantly lowered only in groups treated with 400 and 800 mg/kg of the extract (p < 0.05), whereas other RBCC parameters and white blood cell counts (WBCC) were not significantly affected (p < 0.05). Platelet (PLT) count was also significantly lowered in all extract-treated groups. The extract also significantly reduced RBCC percentage hemolysis (p < 0.05). Conclusions Ajumbise polyherbal may be free of hematoxicity and may improve the integrity of the RBC membrane due to its appreciable antioxidant activity.

Topics: Animals; Antioxidants; Ascorbic Acid; Biphenyl Compounds; Blood Platelets; Erythrocytes; Flavonoids; Hematology; Hemolysis; Leukocytes; Nigeria; Nitric Oxide; Osmotic Fragility; Phenols; Phytotherapy; Picrates; Plant Extracts; Plants, Medicinal; Rats

A series of glutamic acid derivatives was synthesized and evaluated for their antioxidant activity and stability. We found several potent and stable glutamic acid derivatives. Among them, compound 12b exhibited good in vitro activity, chemical stability and cytotoxicity. A prototype compound 12b showed an anti-inflammatory effect in LPS-stimulated RAW 264.7 cell lines and in a zebrafish model.

Topics: Animals; Anti-Inflammatory Agents, Non-Steroidal; Antioxidants; Biphenyl Compounds; Cell Survival; Dose-Response Relationship, Drug; Drug Design; Glutamic Acid; Lipopolysaccharides; Mice; Molecular Structure; Picrates; RAW 264.7 Cells; Structure-Activity Relationship; Zebrafish

Fourteen new polyketides classified as four phthalides, setosphalides A and B, 5- O-desmethylcolletotrialide, and ( S)-colletotrialide (1-4), three isocoumarin derivatives, exserolides I-K (5-7), four pyrones, setosphapyrones A-D (8-11), one furanone (12), and two depsidones (13 and 14), along with 17 known polyketides were isolated from cultures of the sponge-derived fungus Setosphaeria sp. SCSIO41009. The structures and absolute configurations of these new compounds (1-14) were determined by spectroscopic analyses, X-ray diffraction, chiral-phase HPLC analysis, modified Mosher's method, and comparison of ECD spectra to calculations. Setosphalides A (1) and B (2) are the first examples possessing a 5,5 spiroketal skeleton in phthalide derivatives. Botryorhodines I (13) and J (14) showed moderate antifungal activities against the phytopathogenic fungi Colletotrichum asianum and Colletotrichum acutatum. Compound 18 (7- O-demethylmonocerin) exhibited potent radical scavenging activity against DPPH.

Topics: Animals; Ascomycota; Bacteria; Biphenyl Compounds; Circular Dichroism; Fermentation; Free Radical Scavengers; Fungicides, Industrial; Isocoumarins; Magnetic Resonance Spectroscopy; Microbial Sensitivity Tests; Molecular Structure; Phthalic Acids; Picrates; Polyketides; Porifera; Structure-Activity Relationship

The initial steps in preclinical drug developing research concern the synthesis of new compounds for specific therapeutic use which needs to be confirmed by in vitro and then in vivo testing. Nine thiazolidinone derivatives (numerically labeled 1-9) classified as follows: 1,3-thiazole-based compounds (1 and 2); 1,3,4-thiadiazole based compounds (3 and 4); substituted 5-benzylideno-2-adamantylthiazol[3,2-b][1,2,4]triazol-6(5H)ones (5-8); and an ethylaminothiazole-based chalcone (9), were tested for antioxidant activity (AOA) by using three in vitro assays: DPPH (1,1-diphenyl-2-picrylhydrazyl scavenging capacity test); FRAP (ferric reducing antioxidant power test); and TBARS (thiobarbituric acid reactive substances test). Compounds 1-4 and 9 in particular are newly synthesized compounds. Also, traditional antioxidants Vitamins E and C and α-lipoic acid (α-LA) were tested. The results of DPPH testing: Vitamin C 94.35%, Vitamin E 2.99% and α-LA 1.57%; compounds: 4 33.98%; 2 18.73%; 1 15.62%; 5 6.59%; 3 4.99%; 6-9 demonstrated almost no AOA. The results of TBARS testing (% of LPO inhibition): Vitamin C 62.32%; Vitamin E 36.29%; α-LA 51.36%; compounds: 1 62.11%; 5 66.71%; 9 60.93%; 4, 6 and 7 demonstrated ∼50%; 3 and 8 displayed ∼38%; 2 23.51%. By FRAP method, Vitamins E and C showed equal AOA, ∼100%, unlike α-LA (no AOA), and AOA of the tested compounds (expressed as a fraction of the AOA of Vitamin C) were: 2 and 4-75%; 8, 3 and 1-45%; 5-7 and 9-27%. Different red-ox reaction principles between these assays dictate different AOA outcomes for a single compound. Vitamin C appeared to be the superior antioxidant out of the traditional antioxidants; and compound 4 was superior to other tested thiazolidinone derivatives. Vitamin C appeared to be the superior antioxidant out of the traditional antioxidants; and compound 4 was superior to other tested thiazolidinone derivatives. Phenyl-functionalized benzylidene, amino-carbonyl functional domains and chelating ligand properties of the thiazolidinone derivatives correlated with AOA.

Topics: Antioxidants; Ascorbic Acid; Biphenyl Compounds; Oxidation-Reduction; Picrates; Thiadiazoles; Thiazoles; Thiobarbituric Acid Reactive Substances; Thioctic Acid; Vitamin E

The present study aimed to evaluate the effects of grape seed extract (GSE) versus quercetin and vitamin C on in vitro oocyte maturation and embryo development in sheep. The free radical scavenging activity of different concentrations of each product was measured by 1, 1- diphenyl-2-picryl hydrazyl (DPPH). Oocytes were collected from ovaries of slaughtered ewes and matured in TCM-199 medium containing fetal calf serum, follicle stimulating hormone (FSH), estradiol-17 β, sodium pyruvate, and gentamicin sulfate. The in vitro fertilization and culture were performed using Bracket and Oliphant's (BO) medium and modified Charles Rosenkrans medium with amino acids (mCR2aa), respectively. The results showed that the hydroalcoholic extract of grape seed had free radical scavenging activity. IC50 value for GSE, vitamin C, and quercetin was found to be 585 µg/mL, 53 µg/mL, and 43 µg/mL, respectively. The concentrations, which showed beneficial effects on oocyte maturation and early development based on the mean number of cleavage, morula and blastocyst rates, were 25-200 µg/mL, 5 or 15 µg/mL, and 800 µg/mL, respectively, for vitamin C, quercetin and GSE. However, there were no significant differences between different concentrations of GSE and control. Findings also highlight the great effect on blastocyst rate while adding GSE at 800 µg/mL. However, the best rate of blastocyst production was obtained in presence of quercetin. Findings suggested the need for further studies on special molecules derived from GSE.

Topics: Animals; Ascorbic Acid; Biphenyl Compounds; Embryo, Mammalian; Embryonic Development; Estradiol; Female; Fertilization in Vitro; Follicle Stimulating Hormone; Free Radical Scavengers; Grape Seed Extract; Oocytes; Picrates; Primary Cell Culture; Quercetin; Sheep

Topics: Amidines; Animals; Ascorbic Acid; Benzhydryl Compounds; Biphenyl Compounds; Butylated Hydroxyanisole; Butylated Hydroxytoluene; Chromans; Erythrocytes; Free Radical Scavengers; Hydrazines; Hydrogen Peroxide; Imidazolines; Nitric Oxide; Picrates; Rats; Structure-Activity Relationship

Vitamin C (VC) and folic acid (FA) are the important nutrient and antioxidant in human body. In order to improve their stability, their co-loaded liposomes (VCFA-Lip) and chitosan-coated liposomes (CS-VCFA-Lip) are prepared and characterised. The mean particle size of VCFA-Lip and CS-VCFA-Lip is 138 nm and 249 nm, respectively. The encapsulation efficiencies of both drugs for CS-VCFA-Lip are much higher than those for VCFA-Lip. Furthermore, the experimental results show that the antioxidant activity of CS-VCFA-Lip is higher than that of VCFA-Lip. Moreover, the storage stability study reveals that the chitosan coating can efficiently improve the physical stability of VCFA-Lip. These results indicate that stability of VC and FA can be greatly improved after being wrapped by liposomes. In addition, the performance of CS-VCFA-Lip is better than VCFA-Lip, indicating CS-VCFA-Lip can be applied as a promising delivery system for the antioxidant defence system to the food industry and cosmetic industry.

Topics: Antioxidants; Ascorbic Acid; Biphenyl Compounds; Chitosan; Drug Liberation; Drug Stability; Folic Acid; Free Radicals; Hydrogen Peroxide; Liposomes; Picrates; Vitamins

Chitosan oligosaccharide (COS), derived through hydrolysis of chitosan, has been proved to be an effective plant immunity elicitor, eco-friendly, and easily soluble in water, and influenced several secondary metabolites content to improve fruit qualities. COS are widely used in agriculture to improve the defense response in plants. The purpose of this study was to investigate the pre-harvest treatment effect of COS on the quality of strawberry (

Topics: Anthocyanins; Ascorbic Acid; Biphenyl Compounds; Cell Wall; Chitosan; Crops, Agricultural; Flavonoids; Flowers; Food Quality; Fragaria; Gene Expression Regulation, Plant; Oligosaccharides; Picrates; Seedlings; Water

The antioxidant potential of superparamagnetic iron oxide nanoparticles functionalized with chitosan and graphene were examined in the present work. Coprecipitation technique was followed for the synthesis of iron oxide nanoparticles. Graphene-iron oxide nanocomposites were synthesized by mechanical mixing followed by the heat treatment at moderate temperature. The chitosan coated iron oxide nanoparticles were prepared by dispersing nanoparticles in chitosan solution. The nanoparticles/nanocomposites were characterized using XRD, SEM, TEM and HAADF-STEM for phase structure, morphology and elemental analysis. The superparamagnetic behavior of nanoparticles/nanocomposites were confirmed by magnetic measurements using vibrating sample magnetometry. Antioxidant efficacy of these nanoparticles/nanocomposites were investigated in terms of free radical scavenging and reducing potential using an array of in vitro assay system. Ferric reducing antioxidant power (FRAP) and 2,2'-diphenyl-1-picrylhydrazyl (DPPH) were used for the antioxidant capacity. The investigation suggests that the graphene improves the antiradical response of iron oxide nanoparticles at higher concentration which is almost comparable to the ascorbic acid used as standard.

Topics: Antioxidants; Ascorbic Acid; Biphenyl Compounds; Chitosan; Free Radical Scavengers; Graphite; Magnetite Nanoparticles; Particle Size; Picrates

A new class of pyrazolo[4,3-c]quinoline (5a-i, 7a-b) and pyrano[3,2-c]quinoline (9a-i) derivatives were designed and synthesized in moderate to good yields by microwave conditions. To enhance the yield of pyrano[3,2-c]quinoline derivatives, multicomponent one-pot synthesis has been developed. The synthesized compounds were identified by spectral and elemental analyses. Compounds 9a and 9i showed good antibacterial activity against Gram-positive and Gram-negative bacterial strains. All of the new compounds exhibited weak to moderate antioxidant activity, compound 9d exerted significant antioxidant power. The cytotoxicity of these compounds were also evaluated against MCF-7 (breast) and A549 (Lung) cancer cell lines. Most of the compounds displayed moderate to good cytotoxic activity against these cell lines. Compound 9i was found to be significantly active in this assay and also induced cell death by apoptosis. Molecular docking studies were carried out using EGFR inhibitor in order to determine the molecular interactions.

Topics: A549 Cells; Anti-Bacterial Agents; Antineoplastic Agents; Apoptosis; Biphenyl Compounds; Catalytic Domain; ErbB Receptors; Free Radical Scavengers; Gram-Negative Bacteria; Gram-Positive Bacteria; Green Chemistry Technology; Humans; MCF-7 Cells; Molecular Docking Simulation; Nitroquinolines; Picrates; Pyrans; Pyrazoles; Structure-Activity Relationship

Sonnerphenolic C (3), which was predicted in a redox product of epirhododendrin (1) isolated from Acer nikoense, was synthesized for the first time via the epimeric separation of benzylidene acetal intermediates as a key step. From a similar synthetic route, 1 was obtained concisely. As a result of their antioxidative evaluation, only 3 revealed potent activity. The redox transformation of 1 into 3 was achieved in the presence of tyrosinase and vitamin C. Moreover, 3 was identified in the decoction of A. nikoense by HPLC analysis with the effective use of synthesized 3. Thus, a novel naturally occurring antioxidant 3 was developed through the sequential flow including redox prediction, chemical synthesis, evaluation of the activity, and identification as the natural product.

Topics: Acer; Antioxidants; Ascorbic Acid; Biphenyl Compounds; Catechols; Glucosides; Oxidation-Reduction; Picrates; Plant Extracts

The lignan 7'-hydroxymatairesinol (1), extracted from the knotwoods of fir (Abies alba), spruce (Picea abies), and Douglas fir (Pseudotsuga menziesii), exhibited unexpected reactivity when esterification reactions were attempted on the hydroxy group at position C-7'. To circumvent the rapid intramolecular cyclization procedure, leading quantitatively to the lignan conidendrin (7), a simple strategy for 7'-esterification of 1 under mild conditions (three steps, up to 80% overall yield) was developed. Compared to hydroxymatairesinol (1) (log K'

Topics: alpha-Tocopherol; Antioxidants; Biphenyl Compounds; Lignans; Molecular Structure; Nuclear Magnetic Resonance, Biomolecular; Picea; Picrates; Pinus; Stereoisomerism; Tetrahydronaphthalenes

2-O-α-d-Glucopyranosyl-l-ascorbic acid (AA-2G) exhibits biological activities after enzymatic hydrolysis to ascorbic acid (AA) by α-glucosidase. We have found that AA-2G per se exerted radical-scavenging activity toward 1,1-diphenyl-2-picrylhydrazyl radical (DPPH radical). The radical-scavenging property of AA-2G was greatly different from that of AA; that is, the reaction rate with DPPH radical of AA-2G was far slower than that of AA, but the long-lasting radical-scavenging ability per one molecule of AA-2G was superior to that of AA. We purified key intermediates for the characteristic radical-scavenging reaction of AA-2G and carried out time-course studies of the radical-scavenging reactions of the intermediates, AA-2G and AA to determine both the reaction rate and stoichiometry of AA-2G with DPPH radical. One mole of AA-2G quenched 2.7mol of DPPH radical over a period of 120min, while one mole of AA quenched 1.9mol of the radical. The high reaction stoichiometry of AA-2G against DPPH radical was associated with adduct formation of AA-2G with DPPH radical. The radical-scavenging reaction mechanism of AA-2G consists of the following three steps: (1) At an early stage of the reaction, AA-2G scavenged DPPH radical to generate AA-2G radical, (2) AA-2G radical immediately reacted with an additional DPPH radical to give two types of AA-2G-DPPH adducts and (3) AA-2G-DPPH adducts slowly quenched the other DPPH radical to generate several reaction products. Our results suggest the practical value of AA-2G, even before being converted into AA, as a beneficial antioxidant in food and cosmetic applications.

Topics: Ascorbic Acid; Biphenyl Compounds; Free Radical Scavengers; Molecular Structure; Picrates

Camu-camu (Myrciaria dubia) fruit is a rich source of bioactive compounds but its shelf life is rather short. Therefore, this study was aimed to evaluate the effect of inlet air temperature (T) and concentration (C) of maltodextrin and arabic gum on the spray-drying process of commercial camu-camu pulps (São Paulo and Manaus). Moisture, solubility, total phenolics (TP), ascorbic acid (AA), and proanthocyanidins (PAC) contents, and in vitro antioxidant capacity of the powders (FRAP, DPPH, Folin-Ciocalteu's reducing capacity were measured). Arabic gum resulted in better yields (22% to 30%), powder solubility (84% to 90%), and lower losses of analyzed compounds than the powders manufactured with maltodextrin. Overall, inlet air temperature had a lower impact on the responses studied than the concentration of carrier agents. Polynomial equations were generated for AA (R

Topics: Antioxidants; Ascorbic Acid; Biphenyl Compounds; Brazil; Commerce; Desiccation; Food Handling; Food Storage; Fruit; Gum Arabic; Humans; Myrtaceae; Phenols; Picrates; Polysaccharides; Proanthocyanidins; Temperature

Topics: Animals; Anti-Infective Agents; Antioxidants; Ascorbic Acid; Bacteria; Biphenyl Compounds; Candida albicans; Cell Line; Cell Survival; Drug Stability; Hydrogen-Ion Concentration; Mice; Picrates; Thermogravimetry

The aim of the study was to investigate the effects of effects of storage and temperature on the antioxidant potential, vitamin-C contents, total as well as selected individual phenolic acids and flavonoids of fresh aqueous leaves extract of Azadirachta Indica. The antioxidant activity of Azadirachta Indica leaves aqueous extract was determined by scavenging of DPPH free radical, while the phenolic compounds and vitamin-C contents by HPLC method. The analyses were carried out on crude extract of fresh leaves and after storage time of 1, 2 and 3 month at temperature of 20, 30 and 50°C. Storage for longer duration and rise in temperature caused decreasing the phenolic acids and vitamin C contents as well as antioxidant potential. Vitamin C contents were decreased up to 91% upon storage for 3 months at 50°C, while the anti-oxidant potential was decreased 29 %. The effect of storage time and temperature on individual phenolic acid and flavonoids were also remarkable, except ferulic acid which increased upon storage and rise in temperature.

Topics: Antioxidants; Ascorbic Acid; Azadirachta; Biphenyl Compounds; Chromatography, High Pressure Liquid; Drug Stability; Drug Storage; Picrates; Plant Extracts; Plant Leaves; Polyphenols; Temperature; Time Factors

Opioid addiction is associated with oxidative cell injury in neuronal cells. In this study, Bacopa monnieri (L.), a reputed nootropic plant, was evaluated against morphine-induced histopathological changes in the cerebellum of rats. B. monnieri methanolic extract (mBME) (40 mg/kg, p.o) and ascorbic acid (50 mg/kg, i.p) were administered two hours before morphine (20 mg/kg, i.p) for 14 and 21 days. The in vitro antioxidant activity of mBME was determined by 2,2-diphenyl-1-picrylhydrazyl (DPPH) free-radical scavenging assay. Morphine produced vacuolization of basket and stellate cells and reduced the size of Purkinje cells in the cerebellum after 14 days. However, treatment for 21 days was associated with severe shrinkage of Purkinje cells with loss of their characteristic flask-shaped appearance as well as degeneration of basket, stellate and granule cells. Pretreatment with mBME and ascorbic acid for 14 and 21 days attenuated the morphine-induced histopathological changes in the cerebellum. The EC50 for the DPPH free-radical scavenging assay of mBME (39.06 μ/mL) as compared to ascorbic acid (30.25 μ/mL) and BHT (34.34 μ/mL) revealed that mBME strongly scavenged the free-radicals and thus possessed an efficient antioxidant propensity. These results concluded that B. monnieri having strong antioxidant activity exerted a protective effect against morphineinduced cerebellar toxicity.

Topics: Analgesics, Opioid; Animals; Ascorbic Acid; Bacopa; Biphenyl Compounds; Butylated Hydroxytoluene; Cerebellum; Cytoprotection; Free Radical Scavengers; Male; Morphine; Neuroprotective Agents; Oxidative Stress; Picrates; Plant Extracts; Purkinje Cells; Rats, Sprague-Dawley

Moringa oleifera plant has been widely used for a vast number of folkloric medicinal purposes. The research aimed to investigate the antioxidant and antihyperglycaemic activity of Moringa oleifera leaf extracts obtained using different solvent systems for extraction. The solvent extracts of Moringa oleifera were: water extract (100% MoWE), 50% Methanolic extract (50% MoME), 100% Methanolic extract (100% MoME), 50% Ethanolic extract (50% MoEE), and 100% Ethanolic extract (100% MoEE). The in vitro antioxidant activity was evaluated by the use of the 1,1-diphenyl-2-picryl hydrazyl (DPPH) scavenging assay which showed the hydro-alcoholic extracts to have the highest reducing power, though lower than that of the standard, vitamin C. The hypoglyceamic activity was evaluated for the extracts at graded doses of 200mg/kg, 300mg/kg and 400mg/kg in wistar rats. Relative to the positive control, all treatment groups showed a significant statistical decrease in blood glucose levels. The decrease trends as metformin (84.14%) >50% MoEE 300mg/kg (83.72%) >MoWE 300mg/kg (82.42%) > 50% MoEE 200mg/kg (82.32%) >100% MoEE 400mg/kg (81.96%) >50% MoME (80.69%) >100% MoME 300mg/kg (78.47%) >50% MoME 200mg/kg (66.34%). Overall, the 50% MoEE at a dose of 300mg/kg showed superior antioxidant properties, weight restorative and pronounced hypoglyceamic effects. The weight restorative effect of high dose alcoholic extract of Moringa oleifera was also observed in the study. This study establishes novel and foundational considerations for further isolation and characterization studies for the hypoglyceamic compounds in the plant.

Topics: Alloxan; Animals; Antioxidants; Ascorbic Acid; Biphenyl Compounds; Blood Glucose; Diabetes Mellitus, Experimental; Dose-Response Relationship, Drug; Ethanol; Female; Hypoglycemic Agents; Male; Metformin; Methanol; Moringa oleifera; Picrates; Plant Extracts; Plant Leaves; Rats, Wistar; Solvents; Water

As trisodium L-ascorbyl 2-phosphate 6-palmitate (APPS), an ascorbic acid derivative, is an amphiphilic substance, it forms micelles in aqueous solutions. Micelles are used as drug carriers and can emulsify drugs that are poorly soluble in water, such as nadifloxacin (NDFX). The purpose of this study was to prepare nanocarriers using APPS to carry NDFX into Yucatan micropig skin.. After synthesis of the NDFX nanoparticles by using the hydration method, physical evaluations were carried out that included assessments of particle size and zeta potential, encapsulation efficiency, particle structure by transmission electron microscopy,. The encapsulation efficiency of NDFX in the nanoparticles was approximately 75%. With added magnesium chloride, the nanoparticles remained stably dispersed in aqueous solution for at least 14 days at 25°C under protection from light. In addition, the nanoparticle formulation improved the skin permeability of NDFX.. APPS-derived nanoparticles were shown to be useful as skin-targeting nanocarriers.

Topics: Administration, Cutaneous; Animals; Ascorbic Acid; Biphenyl Compounds; Drug Carriers; Drug Liberation; Emulsions; Fluoroquinolones; Humans; Micelles; Nanoparticles; Particle Size; Permeability; Picrates; Quinolizines; Skin; Skin Absorption; Solubility; Surface Properties; Swine

Nano-TiO. With increased barrier properties, NTLDPE packaging quickly formed a relative lower O. These data indicate that the beneficial effects of NTLDPE packaging on postharvest quality and antioxidant capacity of strawberry are probably associated with the promotion of ROS scavenging and related antioxidant enzyme activities, and NTLDPE packaging together with refrigeration storage is a promising method for strawberry fruit preservation. © 2016 Society of Chemical Industry.

Topics: Anthocyanins; Antioxidants; Ascorbic Acid; Atmosphere; Biphenyl Compounds; Carbon Dioxide; Cold Temperature; Food Packaging; Food Preservation; Food Storage; Fragaria; Fruit; Humans; Hydrogen Peroxide; Nanostructures; Oxygen; Phenols; Picrates; Polyethylene; Refrigeration; Superoxides; Titanium

Extracts from the wood of Juniperus excelsa ssp. polycarpos were analysed for their antioxidant activity using the DPPH method and compared with ascorbic acid and butylated hydroxytoluene. The most active extracts were analysed for their chemical composition using gas chromatography-mass spectrometry. Acetone extract was found to be moderately active as an antioxidant agent at 58.38%, which was lower than the value of vitamin C (98.56%) at the concentration of 14.20 mg/mL. The major components identified in the acetone extract as trimethylsilyl (TMS) derivatives were pimaric acid TMS (24.56%), followed by α-d-glucopyranoside,1,3,4,6-tetrakis-O-(TMS)-β-d-fructofuranosyl 2,3,4,6-tetrakis-O-(TMS) (21.39%), triflouromethyl-bis-(TMS)methyl ketone (9.32%), and cedrol (0.72%). The dissolved water:methanol (1:1 v/v) partitioned from acetone extract afforded 12 fractions; among them, the F9 fraction was found to have good antioxidant activity (88.49%) at the concentration of 14.20 mg/mL. The major compounds identified in F9 fraction were α-d-glucopyranoside, 1,3,4,6-tetrakis-O-(TMS) (20.22%) and trifluoromethyl-bis-(TMS)methyl ketone (5.10%).

Topics: Acetone; Antioxidants; Ascorbic Acid; Biphenyl Compounds; Butylated Hydroxytoluene; Gas Chromatography-Mass Spectrometry; Juniperus; Methanol; Picrates; Plant Extracts; Solvents; Water; Wood

The antioxidant properties of trans-aconitic acid (TAA) alone or in the presence of usual antioxidants were assessed by DPPH assay. The IC50 value equal to 70mM was very high compared to usual antioxidants (vitamin C and trolox). A joint experimental/theoretical study suggested that hydrogen atom abstraction in TAA by DPPH was located on -CH2- methylene bridge because the corresponding radical was more stabilized than COO(·) and CC(·) radicals. In combination with antioxidants (vitamin C, gallic acid, caffeic acid, trolox), synergy or additivity effects were noticed. The magnitude of the synergistic effect varied between 1.06 and 1.24 depending on the type and concentration of antioxidant for a concentration of TAA equal to 22.3mM. Especially, the addition of TAA at a concentration below 32mM to a solution containing 20μM of vitamin C had a synergy effect. Beyond this concentration, TAA showed an additive effect.

Topics: Aconitic Acid; Antioxidants; Ascorbic Acid; Biphenyl Compounds; Free Radical Scavengers; Gallic Acid; Picrates; Plant Extracts

Using a click chemistry approach, a series of gallic-acid-1-phenyl-

Topics: Ascorbic Acid; Biphenyl Compounds; Dietary Supplements; Esters; Food Technology; Free Radical Scavengers; Gallic Acid; Picrates

Four new quinonoid naphthopyranones, ophioparmin (1), 4-methoxyhaemoventosins (2a and 2b), and 4-hydroxyhaemoventosin (3), together with anhydrofusarubin lactone (4) and haemoventosin (5) were isolated from the fruiting bodies of Ophioparma ventosa, a crustose lichen. Their structures were determined by spectroscopic analyses, and the absolute configurations of 1 and 2 were elucidated through experimental and calculated electronic circular dichroism analyses. Compounds 1, 2, and 5 exhibited moderate to strong antioxidant activities. The main pigment haemoventosin exhibited significant cytotoxicity toward a panel of nine cell lines.

Topics: Antineoplastic Agents; Biphenyl Compounds; Circular Dichroism; Drug Screening Assays, Antitumor; Fruiting Bodies, Fungal; Humans; Inhibitory Concentration 50; Lichens; Molecular Structure; Naphthoquinones; Nuclear Magnetic Resonance, Biomolecular; Picrates; Pyrans

Phytochemical analysis of the leaves of Garcinia travancorica, a hitherto uninvestigated endemic species to the Western Ghats of south India, resulted in isolation and characterisation of the polyisoprenylated benzophenones 7-epi-nemorosone (1) and garcinol (2) along with biflavonoids GB-1a (3), GB-1 (4), GB-2 (5), morelloflavone (6) and morelloflavone-7″-O-β-D-glycoside or fukugiside (7). The compounds were identified using various spectroscopic techniques, mainly through NMR and MS. The methanol extract and the biflavonoids 3, 4, 5 and 7 showed potential in vitro antioxidant activities. The IC50 value of the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity of compound 7 was 8.34 ± 2.12 μg/mL, comparable to that of standard ascorbic acid (3.2 ± 0.50 μg/mL). In the superoxide radical scavenging assay, compound 7 gave IC50 value of 6.95 ± 1.33 μg/mL close to standard ascorbic acid with IC50 value of 5.8 ± 0.25 μg/mL. Validated HPTLC estimation revealed G. travancorica as a rich source of morelloflavone-7″-O-β-D-glycoside (7.12% dry wt. leaves).

Topics: Antioxidants; Ascorbic Acid; Benzophenones; Biflavonoids; Biphenyl Compounds; Drug Evaluation, Preclinical; Free Radical Scavengers; Garcinia; Glycosides; India; Inhibitory Concentration 50; Magnetic Resonance Spectroscopy; Molecular Structure; Phytochemicals; Picrates; Plant Extracts; Plant Leaves; Terpenes

Two new phenolic compounds, 4-O-glucopyranosyl-5-O-caffeoylshikimic acid (1) and 2,3-digalloyl oregonin (2), were isolated along with eight known phenolic compounds (3-10) from an 80% acetone extract of Alnus sibirica leaves. The chemical structures of these compounds were elucidated using 1D/2D nuclear magnetic resonance and high resolution-MS. The anti-oxidative activities of these compounds were determined by assaying their 1,1-diphenyl-2-picrylhydrazyl radical and nitroblue tetrazolium superoxide anion scavenging activity. All of the isolated phenolic compounds (1-10) exhibited potent anti-oxidative activities. In particular, 2 and 4, which are diarylheptanoids, and 10 which is ellagitannin exhibited excellent anti-oxidative activities with almost the same potency as that of the positive controls L-ascorbic acid and allopurinol.

Topics: Alnus; Antioxidants; Ascorbic Acid; Biphenyl Compounds; Diarylheptanoids; Drug Evaluation, Preclinical; Free Radical Scavengers; Gallic Acid; Glucosides; Hydrolyzable Tannins; Magnetic Resonance Spectroscopy; Phenols; Picrates; Plant Extracts; Plant Leaves; Shikimic Acid; Superoxides

This study initially aimed to depict the molecular rationale evolving the role of lycopene in inhibiting the enzymatic activity of β-hydroxy-β-methylglutaryl-CoA (HMG-CoA) reductase via in vitro and in silico analysis. Our results illustrated that lycopene exhibited strong HMG-CoA reductase inhibitory activity (IC50 value of 36 ng/ml) quite better than pravastatin (IC50 = 42 ng/ml) and strong DPPH free radical scavenging activity (IC50 value = 4.57 ± 0.23 μg/ml) as compared to ascorbic acid (IC50 value = 9.82 ± 0.42 μg/ml). Moreover, the Ki value of lycopene (36 ng/ml) depicted via Dixon plot was well concurred with an IC50 value of 36 ± 1.8 ng/ml. Moreover, molecular informatics study showed that lycopene exhibited binding energy of -5.62 kcal/mol indicating high affinity for HMG-CoA reductase than HMG-CoA (ΔG: -5.34 kcal/mol). Thus, in silico data clearly demonstrate and support the in vitro results that lycopene competitively inhibit HMG-CoA reductase activity by binding at the hydrophobic portion of HMG-CoA reductase.

Topics: Animals; Antioxidants; Ascorbic Acid; Biphenyl Compounds; Carotenoids; Computer Simulation; Free Radical Scavengers; Hydroxymethylglutaryl-CoA Reductase Inhibitors; Hypolipidemic Agents; Informatics; Lycopene; Picrates; Pravastatin

Syntheses of coumarins, which are a structurally interesting antioxidant activity, was done in this article. The modification of 7-hydroxycoumarin by different reaction steps was done to yield target compounds. Molecular structures were characterized by different spectroscopical techniques (Fourier transformation infrared and nuclear magnetic resonance). Antioxidant activities were performed by using various in vitro spectrophometric assays against 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical and hydrogen peroxide (H2O2). All compounds exhibited high efficiency as antioxidants compared to ascorbic acid. The highest efficiency scavenging activity was found for compound 3 (91.0 ± 5.0), followed by compounds 2 and 4 (88.0 ± 2.00; and 87.0 ± 3.00). Ascorbic acid C was used as a standard drug with a percentage inhibition of 91.00 ± 1.5. The mechanism of the synthesized compounds as antioxidants was also studied. Hartree-Fock-based quantum chemical studies have been carried out with the basis set to 3-21G, in order to obtain information about the three-dimensional (3D) geometries, electronic structure, molecular modeling, and electronic levels, namely HOMO (highest occupied molecular orbital) and LUMO (lowest unoccupied molecular orbital), to understand the antioxidant activity for the synthesized compounds.

Topics: Antioxidants; Ascorbic Acid; Biphenyl Compounds; Coumarins; Hydrogen Peroxide; Models, Molecular; Molecular Structure; Picrates

Fresh red currants were dried by vacuum drying process under different drying conditions. Box-Behnken experimental design with response surface methodology was used for optimization of drying process in terms of physical (moisture content, water activity, total color change, firmness and rehydratation power) and chemical (total phenols, total flavonoids, monomeric anthocyanins and ascorbic acid content and antioxidant activity) properties of dried samples. Temperature (48-78 °C), pressure (30-330 mbar) and drying time (8-16 h) were investigated as independent variables. Experimental results were fitted to a second-order polynomial model where regression analysis and analysis of variance were used to determine model fitness and optimal drying conditions. The optimal conditions of simultaneously optimized responses were temperature of 70.2 °C, pressure of 39 mbar and drying time of 8 h. It could be concluded that vacuum drying provides samples with good physico-chemical properties, similar to lyophilized sample and better than conventionally dried sample.

Topics: Anthocyanins; Antioxidants; Ascorbic Acid; Biphenyl Compounds; Desiccation; Freeze Drying; Fruit; Models, Theoretical; Phenols; Picrates; Pressure; Ribes; Serbia; Temperature; Vacuum

This study aimed to characterize the effects of chitosan-g-caffeic acid (CTS-g-CA) on improving the quality and extending the shelf life of postharvest mulberry fruit during storage at 4 °C for 18 d. CTS-g-CA was enzymatically synthesized using laccase from Pleurotus ostreatus as a catalyst. The synergistic effects of CTS-g-CA treatment on mulberry fruit were evaluated using a co-toxicity factor (cf). The results showed that the rotting rate of CTS-g-CA-treated fruit was 37.67% (compared with that of the control at 97.67%) on day 18. The weight loss and malondialdehyde (MDA) contents of the CTS-g-CA-treated mulberry fruit were significantly lower (P < 0.05) than those of the control, CA, CTS, and CA+CTS treatments. Moreover, the DPPH and ABTS radical scavenging activities of the CTS-g-CA treatment were both higher than those of the control. Furthermore, the CTS-g-CA treatment also maintained higher levels of main active substances, such as anthocyanins, ascorbic acid, polyphenols and flavones, in mulberry fruit than the other treatments. Therefore, CTS-g-CA could be used to improve the quality and extend the shelf life of postharvest mulberry fruit during cold storage.

Topics: Anthocyanins; Antioxidants; Ascorbic Acid; Benzothiazoles; Biphenyl Compounds; Caffeic Acids; Chitosan; Cold Temperature; Food Handling; Food Preservation; Food Storage; Fruit; Humans; Malondialdehyde; Morus; Picrates; Polyphenols; Refrigeration; Sulfonic Acids

Cactus pear (Opuntia ficus-indica L.) is widely distributed in the arid and semi-arid regions throughout the world. In the last decades, the interest towards vegetative crop increased, and cladodes are exploited for nutraceutical and health-promoting properties. This study aimed at investigating the capacity of selected lactic acid bacteria to increase the antioxidant and anti-inflammatory properties of cactus cladodes pulp, with the perspective of producing a functional ingredient, dietary supplement or pharmaceutical preparation. Preliminarily, the antioxidant activity was determined through in vitro assays. Further, it was confirmed through ex vivo analysis on intestinal Caco-2/TC7 cells, and the profile of flavonoids was characterized. Cactus cladode pulp was fermented with lactic acid bacteria, which were previously selected from plant materials. Chemically acidified suspension, without bacterial inoculum and incubated under the same conditions, was used as the control. Lactobacillus plantarum CIL6, POM1 and 1MR20, Lactobacillus brevis POM2 and POM4, Lactobacillus rossiae 2LC8 and Pediococcus pentosaceus CILSWE5 were the best growing strains. Fermentation of cladode pulp with L. brevis POM2 and POM4 allowed the highest concentration of γ-amino butyric acid. Lactic acid fermentation had preservative effects (P<0.05) on the levels of vitamin C and carotenoids. Two flavonoid derivatives (kaemferol and isorhamnetin) were identified in the ethyl acetate extracts, which were considered to be the major compounds responsible for the increased radical scavenging activity. After inducing oxidative stress by IL-1β, the increased antioxidant activity (P<0.05) of fermented cladode pulp was confirmed using Caco-2/TC7 cells. Fermented cladode pulp had also immune-modulatory effects towards Caco-2 cells. Compared to the control, fermented cladode pulp exhibited a significantly (P<0.05) higher inhibition of IL-8, TNFα and prostaglandins PGE2 synthesis. The highest functional effect was found using ethyl acetate extracts. In conclusion, fermentation, especially with L. plantarum strains and L. brevis POM4, enhanced the antioxidant and immune-modulation features of cladode pulp.

Topics: Anti-Inflammatory Agents; Antioxidants; Ascorbic Acid; Biphenyl Compounds; Caco-2 Cells; Carotenoids; Dinoprostone; Electric Impedance; Epithelial Cells; Fermentation; Flavonoids; Free Radical Scavengers; Humans; Interleukin-8; Lactic Acid; Nitric Oxide; Opuntia; Phenols; Picrates; Plant Extracts; Reactive Oxygen Species; Tumor Necrosis Factor-alpha

A series of novel l-ascorbyl fatty acid esters were synthesized by catalization of Novozym(®) 435 under ultrasonic irradiation and characterized by infrared spectroscopy, electrospray ionization mass spectra, and nuclear magnetic resonance. Their properties especially antioxidant activity and stability were investigated. The results showed that the reducing power, the scavenging activity of hydroxyl radical and 2,2-diphenyl-1-picrylhydrazyl radical were decreased with the increase of the number of carbon atoms in fatty acid. The hydroxyl radical scavenging activity and reducing power of l-ascorbyl saturated fatty acid esters were better than that of tert-butylhydroquinone. The induction period in lipid oxidation of l-ascorbyl saturated fatty acid esters and tert-butylhydroquinone were longer than that of l-ascorbyl unsaturated fatty acid esters and l-ascorbic acid both in soybean oil and lard. Besides, the l-ascorbyl fatty acid esters showed different stabilities in different conditions by comparing with l-ascorbic acid, and the l-ascorbyl saturated fatty acid esters were more stable than l-ascorbyl unsaturated fatty acid esters in ethanol solution.

Topics: Antioxidants; Ascorbic Acid; Biphenyl Compounds; Dietary Fats; Esters; Fatty Acids; Fatty Acids, Unsaturated; Food Preservatives; Humans; Hydroquinones; Lipase; Lipid Peroxidation; Oxidation-Reduction; Picrates; Soybean Oil; Ultrasonic Waves; Ultrasonics

Methanol extracts from 50 batches of Lycium barbarum (L. barbarum, wolfberry) in China were compared and characterized using high-performance thin-layer chromatography coupled with 2,2-diphenyl-1-picrylhydrazyl (DPPH) bioautography (HPTLC-DPPH) and electrospray ionization quadrupole time-of-flight tandem mass spectrometry (ESI-Q-TOF-MS/MS), respectively. Results showed that similar components occupying the major antioxidant activity existed in L. barbarum collected from different origins. However, the average antioxidant capacities of methanol extracts of L. barbarum collected in Ningxia were significantly higher than those of Qinghai, Xinjiang, Inner Mongolia, and Gansu, which may contribute to rational use of L. barbarum in China. Furthermore, the chemical structure of compound with the highest antioxidant capacity was tentatively identified as 2-O-β-d-glucopyranosyl-l-ascorbic acid using ESI-Q-TOF-MS/MS analysis, which possessed high potentials to be used as an antioxidant biomarker for the quality control of L. barbarum. Results are helpful for the bioactivity-based quality control of L. barbarum, and beneficial for the improvement of their performance in functional/health foods area, suggesting that HPTLC-DPPH bioautography with ESI-Q-TOF-MS/MS could be used as a routine approach for quality control of antioxidant components in L. barbarum.

Topics: Antioxidants; Ascorbic Acid; Biphenyl Compounds; China; Chromatography, High Pressure Liquid; Chromatography, Thin Layer; Fruit; Humans; Lycium; Oxidation-Reduction; Picrates; Plant Extracts; Spectrometry, Mass, Electrospray Ionization; Tandem Mass Spectrometry

The use of herbal medicine and traditional healing practices for diagnosis, treatment and prevention of illness and ailment continue to have more awareness among the scientific community due to their safety and also as a source of alternatives to synthetic products. This research assessed the total phenolic compounds and in vitro total antioxidant potentials of water extracts in selected species of Zingiberaceae rhizomes use as spice, drinks and medicine. DPPH and FRAP were used to determine the antioxidant capacity, total flavonoid, phenolic acids and polyphenol contents assays to evaluate the quality of the antioxidant activity and the control was ascorbic acid. The results showed that all extracts contain significant antioxidant activity with Zingiber officinale having the highest activity in all assays. DPPH (222.30mg/TE/g DW), FRAP (98.04mg/TE/g DW), Flavonoid (38.58mg/NGN/g DW) phenolic acid (10.78mg/GAE/g DW) and polyphenols (22.84mg/GAE/g DW). Significant and positive linear correlation were found in DPPH, FRAP and total flavonoid, phenolic acids and polyphenol contents. This study reveals some phytochemicals present in Zingiberaceae species, which might be responsible for their biological activities and reason for it use in folkloric medicine in Southeast Asia.

Topics: Ascorbic Acid; Biphenyl Compounds; Chemical Fractionation; Folklore; Free Radical Scavengers; Humans; Malaysia; Medicine, Traditional; Phenols; Phytotherapy; Picrates; Plants, Medicinal; Rhizome; Solvents; Water; Zingiberaceae

Skin is the outermost layer of the human body that is constantly exposed to environmental stressors, such as UV radiation and toxic chemicals, and is susceptible to mechanical wounding and injury. The ability of the skin to repair injuries is paramount for survival and it is disrupted in a spectrum of disorders leading to skin pathologies. Diabetic patients often suffer from chronic, impaired wound healing, which facilitate bacterial infections and necessitate amputation. Here, we studied the effects of gallic acid (GA, 3,4,5-trihydroxybenzoic acid; a plant-derived polyphenolic compound) on would healing in normal and hyperglucidic conditions, to mimic diabetes, in human keratinocytes and fibroblasts. Our study reveals that GA is a potential antioxidant that directly upregulates the expression of antioxidant genes. In addition, GA accelerated cell migration of keratinocytes and fibroblasts in both normal and hyperglucidic conditions. Further, GA treatment activated factors known to be hallmarks of wound healing, such as focal adhesion kinases (FAK), c-Jun N-terminal kinases (JNK), and extracellular signal-regulated kinases (Erk), underpinning the beneficial role of GA in wound repair. Therefore, our results demonstrate that GA might be a viable wound healing agent and a potential intervention to treat wounds resulting from metabolic complications.

Topics: Animals; Antioxidants; Ascorbic Acid; Biphenyl Compounds; Catalase; Cell Line; Cell Movement; Cell Survival; Fibroblasts; Focal Adhesion Kinase 1; Gallic Acid; Gene Expression Regulation; Glucose; Glutathione Peroxidase; Humans; Hydrogen Peroxide; Keratinocytes; MAP Kinase Kinase 4; Mice; Mitogen-Activated Protein Kinase 1; Mitogen-Activated Protein Kinase 3; Models, Biological; Picrates; Signal Transduction; Superoxide Dismutase; Wound Healing

'Ubtan' is a traditional herbal formulation in the Indian system of medicine being used in India and its subcontinent for a long time. Several commercial skin care formulations are marketed throughout this region as the name of Ubtan. Therefore, it is worthwhile to evaluate Ubtan in respect of its efficacy as skin care formulation.. The present study was designed for the preparation of Ubtan and standardization through the chromatographic techniques by using suitable phyto-markers. Further, its antioxidant, sun protection factor (SPF) and anti-tyrosinase potential have been explored.. Four in-house formulations (UF-1, UF-2, UF-3 and UF-4) were prepared by mixing a varied quantity of each powdered plants, i.e. turmeric (Curcuma longa L.), Chickpea (Cicer arietinum L.) and sandalwood (Santalum album L.). Optimization of the formulations was made by evaluating its biological activity through in vitro assay. Evaluation of physicochemical properties of the optimized formulation (UF-1) has been carried out by analysis of pH, flow properties and stability. Moreover, RP-HPLC (reverse phase - high performance liquid chromatography) and HPTLC (high performance thin layer chromatography) standardization of UF-1 was performed for its quantitative and qualitative analysis.. Ubtan formulations (UF-1to UF-4) showed free radical scavenging and ferric reducing potential. It may be due to its high phenolic and flavonoid content. Statistically, significant Pearson's correlation (r) was confirmed the positive correlation between phenolic content and SPF of the formulations. The tyrosinase inhibition study indicated that the formulations showed both diphenolase and monophenolase inhibitory activity. Among four formulations, UF-1 showed notable biological activity (p<0.05). The content of curcumin and ascorbic acid was found to be 1.6% and 2.1% w/w respectively in UF-1 through RP-HPLC estimation. Physiochemical properties of the UF-1 exhibited good flow rate and aqueous solubility. From the stability studies, it can be anticipated that the UF-1 was stable at 40°C for longer periods. Microbial load count and heavy metal content (lead-Pb, arsenic-As, mercury-Hg and cadmium-Cd) of the formulation was also within the permissible limit of a pharmacopeial standard.. This scientific exploration helps to set the quality and safety standard of traditional cosmetic formulation, Ubtan and its further use as an herbal skin care product.

Topics: Antioxidants; Ascorbic Acid; Bacterial Load; Biphenyl Compounds; Chromatography, High Pressure Liquid; Chromatography, Reverse-Phase; Chromatography, Thin Layer; Cicer; Consumer Product Safety; Curcuma; Curcumin; Dermatologic Agents; Dose-Response Relationship, Drug; Drug Compounding; Drug Contamination; Drug Stability; Enzyme Inhibitors; Ferricyanides; Hydrogen-Ion Concentration; India; Medicine, Traditional; Metals, Heavy; Monophenol Monooxygenase; Oxidation-Reduction; Phytotherapy; Picrates; Plant Preparations; Plants, Medicinal; Powders; Quality Control; Rheology; Risk Assessment; Santalum; Skin Care; Solubility; Spectrophotometry, Atomic; Spectrophotometry, Ultraviolet; Sunscreening Agents

It is well known that Allium sativum has potential applications to clinical treatment of various cancers due to its remarkable ability in eliminating free radicals and increasing metabolism. An allyl-substituted cysteine derivative - S-allyl-L-cysteine (SAC) was separated and identified from Allium sativum. The extracted SAC was reacted with 1-pyrenemethanol to obtain pyrene-labelled SAC (Py-SAC) to give SAC fluorescence properties. Molecular detection of Py-SAC was conducted by steady-state fluorescence spectroscopy and time-resolved fluorescence method to quantitatively measure concentrations of Py-SAC solutions. The ability of removing 1,1-diphenyl-2-picrylhydrazyl (DPPH) and hydroxyl radical using Py-SAC was determined through oxygen radical absorbance capacity (ORAC). Results showed the activity of Py-SAC and Vitamin C (VC) with ORAC as index, the concentrations of Py-SAC and VC were 58.43 mg/L and 5.72 mg/L respectively to scavenge DPPH, and 8.16 mg/L and 1.67 mg/L to scavenge •OH respectively. Compared with VC, the clearance rates of Py-SAC to scavenge DPPH were much higher, Py-SAC could inhibit hydroxyl radical. The ability of removing radical showed a dose-dependent relationship within the scope of the drug concentration.

Topics: Antioxidants; Ascorbic Acid; Biphenyl Compounds; Cysteine; Free Radical Scavengers; Garlic; Hydroxyl Radical; Picrates; Pyrenes; Spectrometry, Fluorescence

An efficient method for the degradation of polysaccharides isolated from Sargassum fusiforme (PSF) was developed by using ascorbic acid in combination with H

Topics: Antioxidants; Ascorbic Acid; Biphenyl Compounds; Enzyme Inhibitors; Factor Analysis, Statistical; Fungal Polysaccharides; Hydrogen Peroxide; Hydrolysis; Hydroxyl Radical; Molecular Weight; Monophenol Monooxygenase; Oxidation-Reduction; Picrates; Sargassum; Superoxides; Temperature

Lichens are considered a great bio-resource because they produce large numbers of secondary metabolites with many biological activities; however, they have not been cultivated under artificial conditions to date. As a result, lichen substances from natural sources are limited and have not been widely utilized in commercial applications. Accordingly, interest in lichen-associated fungi, especially endogenic fungi, has increased. Ultraviolet (UV) radiation in sunlight is harmful to human health, resulting in demand for effective UV filtering agents for use in sunscreen. In this study, we purified (3

Topics: Animals; Anti-Infective Agents; Antioxidants; Ascorbic Acid; Biphenyl Compounds; Butylated Hydroxyanisole; Candida albicans; Cell Line; Gram-Negative Bacteria; Gram-Positive Bacteria; Humans; Isocoumarins; Keratinocytes; Lichens; Lipid Peroxidation; Melanins; Melanoma, Experimental; Mice; Picrates; Saccharomycetales; Skin Neoplasms; Sunscreening Agents; Superoxides

Phytochemical investigation of an extract of the aerial part of Barleria lupulina resulted in the identification of four new iridoid glycosides (1-4), together with 14 known analogues (5-18). The structures of 1-4 were determined through 1D and 2D NMR spectroscopic data analysis, HRMS, and acid hydrolysis. This is the first report of iridoid glycosides with a formate group. The free-radical scavenging activity of compounds 9, 12, and 15-17 was assessed using the DPPH assay. Compounds 16 and 17 scavenged DPPH radicals weakly with IC50 values of 97.5 and 78.6 μg/mL, respectively.

Topics: Acanthaceae; Biphenyl Compounds; Free Radical Scavengers; Inhibitory Concentration 50; Iridoid Glycosides; Molecular Structure; Picrates; Plant Components, Aerial; Plant Extracts; Vietnam

Two new indole alkaloids chaetocochin J (1) and chaetoglobinol A (8), along with chetomin (2), chetoseminudin A (3), cochliodinol (9), and semicochliodinol (10), were isolated from the rice culture of the fungus Chaetomium globosum. Their structures were elucidated by spectral analysis. Three new epipolythiodioxopiperazines, chaetocochins G-I (5-7), were identified by the combination of UPLC and mass spectrometric analysis. Chaetocochin I contained two sulfur bridges, one formed by three sulfur atoms between C-3 and C-11a, and the other formed by four sulfur atoms between C-3' and C-6'. Chaetocochin I was readily transformed into chetomin (2), chetoseminudin A (3), chaetocochin D (4), chaetocochin G (5), and chaetocochin H (6) by losing sulfur atoms. Compounds 1-3, and 8 exhibited antibacterial activities against Bacillus subtilis with MICs of 25, 0.78, 0.78, and 50 μg/mL, respectively, but not against Gram-negative bacterium (Escherichia coli). Compounds 2 and 8 were inactive against Candida albicans, Fusarium graminearum, Fusarium vasinfectum, Saccharomyces cerevisiae, and Aspergillus niger even at the high concentrations of 200 and 100 μg/mL, respectively. Compound 8 showed free radical scavenging capacity against the 1,1-diphenyl-2-picryl-hydrazyl (DPPH) and 2,2'-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid radical (ABTS(+•)), with IC50 values of 143.6 and 45.2 μM, respectively. The free radical scavenging capacity rates of compounds 1-3 on the DPPH and ABTS(+•) were less than 20% at the test concentrations (89.9-108.3 μM). The superoxide anion radical scavenging assay indicated that compounds 1-3, and 8 showed 14.8% (90.9 μM), 18.1% (90.9 μM), 51.5% (88.3 μM), and 30.4% (61.3 μM) superoxide anion radical scavenging capacity, respectively.

Topics: Anti-Bacterial Agents; Bacillus subtilis; Benzothiazoles; Biphenyl Compounds; Chaetomium; Escherichia coli; Indole Alkaloids; Microbial Sensitivity Tests; Molecular Structure; Nuclear Magnetic Resonance, Biomolecular; Oryza; Picrates; Piperazines; Sulfonic Acids

Breast cancer is probably the most prevalent cancer in women. The development of resistance to therapeutic agents and lack of targeted therapy for breast cancer cells provide motivation to identify new compounds for the treatment. With this objective in mind, a new series of 3-fluoro-4-methoxyphenyl group based 1,3,5-trisubstituted aryl-5-hydroxypyrazoline analogues 4a-l was synthesized through multi-step reaction sequence. The structures of the newly synthesized compounds were confirmed by IR, (1)H NMR, (13)C NMR, LC-MS and elemental analysis. They were screened for their in vitro anticancer and in vitro antioxidant activities. Among the tested compounds 4h, 4c and particularly 4i displayed promising cytotoxic effect on breast cancer cell lines. The compounds were also found to possess antioxidant activity when tested against DPPH free radical. Overall, this work has contributed to the development of promising leads for anticancer and antioxidant activities.

Topics: Animals; Antineoplastic Agents; Antioxidants; Biphenyl Compounds; Cell Line, Tumor; Cell Proliferation; Chlorocebus aethiops; Crystallography, X-Ray; Dose-Response Relationship, Drug; Drug Screening Assays, Antitumor; Fluorine; Free Radicals; Humans; MCF-7 Cells; Models, Molecular; Molecular Structure; Picrates; Pyrazoles; Structure-Activity Relationship; Vero Cells

A polyamide column chromatography method using an aqueous ammonia mobile phase was developed for large-scale accumulation of water-soluble indoline amide glucosides from a medicinal plant, Portulaca oleracea. Ten new [oleraceins H, I, K, L, N, O, P, Q, R, S (1-10)] and four known [oleraceins A-D (11-14)] indoline amide glucosides were further purified and structurally characterized by various chromatographic and spectroscopic methods. The DPPH radical scavenging activities of oleraceins K (5) and L (6), with EC50 values of 15.30 and 16.13 μM, respectively, were twice that of a natural antioxidant, vitamin C; the EC50 values of the 12 other indoline amides, which ranged from 29.05 to 43.52 μM, were similar to that of vitamin C. Structure-activity relationships indicated that the DPPH radical scavenging activities of these indoline amides correlate with the numbers and positions of the phenolic hydroxy groups.

Topics: Alkaloids; Antioxidants; Biphenyl Compounds; Drugs, Chinese Herbal; Free Radical Scavengers; Glucosides; Indoles; Molecular Structure; Nuclear Magnetic Resonance, Biomolecular; Phenols; Picrates; Plant Components, Aerial; Plants, Medicinal; Portulaca; Structure-Activity Relationship

Freshly prepared, hand-pressed strawberry fruit juice was exposed to ultraviolet radiation (254 nm) at room temperature (25 ℃ ± 1 ℃) for 15, 30 and 60 min with 0 min serving as control. Results revealed decrease in pH, total soluble solids and titratable acidity, while colour parameters (L*, a* and b* values) and clarity of juice (% transmittance) increased significantly. All the results corresponded to exposure time to ultraviolet radiation. Bioactive compounds (total phenolics, ascorbic acid and anthocyanins) decreased along with a recorded reduction in polyphenol oxidase enzyme and 1,1-diphenyl-2-picryl hydrazyl radical scavenging activities, which were again dependent on exposure time. Results on the microbial studies showed significant reduction by 2-log cycles in aerobic plate count as well as in total yeast and mould counts. Though negative results were observed for certain parameters, this is the first time it was endeavoured to demonstrate the impact of ultraviolet radiation radiation on freshly prepared, hand-pressed strawberries juice.

Topics: Anthocyanins; Antioxidants; Ascorbic Acid; Beverages; Biphenyl Compounds; Catechol Oxidase; Food Analysis; Food Microbiology; Food Preservation; Fragaria; Phenols; Picrates; Ultraviolet Rays

Cape gooseberry (Physalis peruviana) is an exotic fruit highly valued for its organoleptic properties and bioactive compounds. Considering that the presence of phenolics and ascorbic acid could contribute to its functional capacity, it is important to investigate the quality parameters, bioactive contents and functional properties with respect to genotype and ripening time. In this study the genotype effect was evaluated in 15 cultivars for two different harvest times. Changes during maturation were recorded in two commercial cultivars within seven levels of maturity.. Multivariate statistical analysis suggested that phenolic content and ORAC value were mainly affected by harvest time and that ascorbic acid content and DPPH level were mainly affected by genotype. In addition, acidity, phenolic content, ORAC value and inhibition of LDL oxidation decreased with maturity, but soluble solids content, ascorbic acid content, β-carotene content and DPPH-scavenging activity were higher in mature fruits.. The phenolic content, ascorbic acid content and antioxidant properties of Cape gooseberry fruit were strongly affected by cultivar, harvest time and maturity state. Consequently, the harvest time must be scheduled carefully to gain the highest proportion of bioactive compounds according to the specific cultivar and the environment where it is grown.

Topics: Antioxidants; Ascorbic Acid; beta Carotene; Biphenyl Compounds; Cholesterol, LDL; Fluoresceins; Fruit; Functional Food; Genotype; Humans; Ouabain; Phenols; Physalis; Picrates; Plant Extracts

A simple and efficient procedure was employed for the synthesis of N'-(1,4-naphtho-quinone-2-yl) isonicotinohydrazide (NIH) by the reaction of 2-hydroxy-1,4-naphthaquinone (lawsone) and isonicotinoyl hydrazine in methanol using ultrasonic irradiation. Lawsone is the principal dye, isolated from the leaves of henna (Lawsonia inermis). Structural modification was done on the molecule aiming to get a more active derivative. The structure of the parent compound and the derivative was characterized by elemental analyses, infrared, electronic, (1)H, (13)C NMR and GC-MS spectra. The fluorescence spectral investigation of the compound was studied in DMSO and ethanol. Single crystal X-ray diffraction studies reveal that NIH crystallizes in monoclinic space group. The DNA cleavage study was monitored by gel electrophoresis method. The synthesized compound was found to have significant antioxidant activity against DPPH radical (IC50=58 μM). The in vitro cytotoxic studies of the derivative against two human cancer cell lines MCF-7 (human breast cancer) and HCT-15 (human colon carcinoma cells) using MTT assay revealed that the compound exhibited higher cytotoxic activity with a lower IC50 value indicating its efficiency in killing the cancer cells even at low concentrations. These results suggest that the structural modifications performed on lawsone could be considered a good strategy to obtain a more active drug.

Topics: Ascorbic Acid; Biphenyl Compounds; Carbon-13 Magnetic Resonance Spectroscopy; Cell Death; Cell Line, Tumor; Crystallography, X-Ray; DNA Cleavage; Electrophoresis, Agar Gel; Free Radical Scavengers; Gas Chromatography-Mass Spectrometry; Humans; Hydrazines; Hydrogen Bonding; Isoniazid; Molecular Conformation; Picrates; Proton Magnetic Resonance Spectroscopy; Reference Standards; Spectrometry, Fluorescence; Spectrophotometry, Ultraviolet; Spectroscopy, Fourier Transform Infrared

Optimised of the extraction of polyphenol from star fruit (Averrhoa carambola) pomace using response surface methodology was carried out. Two variables viz. temperature (°C) and ethanol concentration (%) with 5 levels (-1.414, -1, 0, +1 and +1.414) were used to design the optimisation model using central composite rotatable design where, -1.414 and +1.414 refer to axial values, -1 and +1 mean factorial points and 0 refers to centre point of the design. The two variables, temperature of 40°C and ethanol concentration of 65% were the optimised conditions for the response variables of total phenolic content, ferric reducing antioxidant capacity and 2,2-diphenyl-1-picrylhydrazyl scavenging activity. The reverse phase-high pressure liquid chromatography chromatogram of the polyphenol extract showed eight phenolic acids and ascorbic acid. The extract was then encapsulated with maltodextrin (⩽ DE 20) by spray and freeze drying methods at three different concentrations. Highest encapsulating efficiency was obtained in freeze dried encapsulates (78-97%). The obtained optimised model could be used for polyphenol extraction from star fruit pomace and microencapsulates can be incorporated in different food systems to enhance their antioxidant property.

Topics: Antioxidants; Ascorbic Acid; Averrhoa; Biphenyl Compounds; Chromatography, High Pressure Liquid; Drug Compounding; Ethanol; Ferric Compounds; Food Technology; Freeze Drying; Fruit; Hydrogen-Ion Concentration; Phenols; Picrates; Plant Extracts; Polyphenols; Polysaccharides; Surface Properties; Temperature

Diverse plants species in the forest remain under-utilised and they are mainly consumed only by local people. However, increasing issues in food security prompted the present study, which explores the nutritional and antioxidant aspects of Malaysian under-utilised vegetables. The studied vegetables were Paku Nyai (Stenochlaena palustris), Cemperai (Champereia manillana), Maman Pasir (Cleome viscose), Dudung (Erechtites valerianifolia) and Semambuk (Ardisia pendula).. Overall, these vegetables exhibited a low proximal content but they were high in vitamin C [7.07-1263 mg kg(-1) edible fresh sample (EFS)] and β-carotene content (18.4-43.9 mg kg(-1) kg(-1) EFS). Cemperai had the highest calcium content (565 mg kg(-1) EFS), whereas Semambuk had the highest total phenolic content [28.21 g gallic acid equivalents kg(-1) edible dried sample (EDS)] and antioxidant activity (86.1%) measured using β-carotene bleaching assay. Maman Pasir contained the highest total flavonoid content (39.99 g CE kg(-1) EDS) and 1,1-diphenyl-2-picryl hydrazyl radical scavenging activity (82.2%). The extracts of these vegetables had significantly prevented the oxidation of haemoglobin and low-density lipoprotein, which yielded a reduced production of malondialdehyde.. Semambuk and Maman Pasir are potent to be used as new food and functional food sources as they are rich in nutrients and antioxidants.

Topics: Adult; Antioxidants; Ascorbic Acid; beta Carotene; Biphenyl Compounds; Calcium; Diet; Flavonoids; Healthy Volunteers; Hemoglobins; Humans; Lipid Peroxidation; Lipoproteins, LDL; Magnoliopsida; Malaysia; Malondialdehyde; Nutritive Value; Phenols; Picrates; Plant Extracts; Polyphenols; Vegetables; Young Adult

Eighteen edible plants were assessed for their antioxidant potential based on oxygen radical absorbance capacity (ORAC), 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity, total phenolics, vitamin C content and various lipophilic antioxidants. The inhibitory activities of the plant extracts against the enzymatic activities of α-amylase and α-glucosidase were also evaluated.. The antioxidant and starch hydrolase activities of the plants varied widely across a single batch of analysis. The ORAC and DPPH radical scavenging EC50 values varied between 298 and 1984 Trolox equivalents g(-1) fresh weight and between 91 and 533 mg kg(-1) fresh weight, respectively. The total phenolics and vitamin C contents varied between 32 and 125 mg gallic acid equivalents g(-1) fresh weight and between 96 and 285 µg g(-1) fresh weight, respectively. All the plants contained neoxanthin, violaxanthin, and α- and β-carotene in varying amounts. Coccinia grandis, Asparagus racemosus, Costus speciosus, Amaranthus viridis and Annona muricata displayed the highest inhibitory activities against starch hydrolases. They were the most efficient against the breakdown of seven starches exposed to the two enzymes as well.. Overall, the edible plants were observed to display a high antioxidant potential with starch hydrolase inhibitory properties, which were beneficial in their being recognized as functional food.

Topics: alpha-Amylases; alpha-Glucosidases; Amaranthus; Antioxidants; Ascorbic Acid; Asparagus Plant; Biphenyl Compounds; Carotenoids; Costus; Cucurbitaceae; Diet; Enzyme Inhibitors; Functional Food; Humans; Phenols; Picrates; Plants, Edible; Starch

Isothiocyanates are plant-derived compounds that may be beneficial in the prevention of certain chronic diseases. Yet, by stimulating the production of reactive oxygen species (ROS), isothiocyanates can be genotoxic. Whether antioxidants influence isothiocyanate-induced genotoxicity is unclear, but this situation was clarified appreciably herein. In HCT116 cells, phenethyl isothiocyanate (PEITC) increased ROS production, which was inhibited by N-acetylcysteine (NAC) and deferoxamine (DFO) but not by ascorbic acid (ASC) and trolox (TRX) that were found to be more potent radical scavengers. Surprisingly, ASC and TRX each intensified the DNA damage that was caused by PEITC, but neither ASC nor TRX by themselves caused any DNA damage. In contrast, NAC and DFO each not only attenuated PEITC-induced DNA damage but also attenuated the antioxidant-intensified, PEITC-induced DNA damage. To determine if the DNA damage could be related to possible changes in the major antioxidant defence system, glutathione (GSH) was investigated. PEITC lowered GSH levels, which was prevented by NAC, whereas ASC, TRX and DFO neither inhibited nor enhanced the GSH-lowering effect of PEITC. The GSH synthesis inhibitor, buthionine sulphoxime, intensified PEITC-induced DNA damage, although by itself buthionine sulphoxime did not directly cause DNA damage. The principal findings suggest that ASC and TRX make PEITC more genotoxic, which might be exploited in killing cancer cells as one approach in killing cancer cells is to extensively damage their DNA so as to initiate apoptosis.

Topics: Apoptosis; Ascorbic Acid; Biphenyl Compounds; Chromans; DNA Damage; Drug Evaluation, Preclinical; Free Radical Scavengers; Glutathione; HCT116 Cells; HT29 Cells; Humans; Isothiocyanates; Mutagens; Picrates; Reactive Oxygen Species

New 5-aryl-10-(4-(4-methoxyphenyl)thiazole-2-yl)-9,10-dihydropyrido[2,3-d:5,6-d']dipyrimidinone-2,4,6,8-(1H,3H,5H,7H)-tetraones 6a-d were synthesized through one-pot four-component reaction of aldehydes, barbituric acid, and thiazole using Zn(2+) @KSF under reflux condition. The key features of this reaction are: incorporating four heterocyclic rings, using a heterogeneous and efficient catalyst, high yield, and easy-to-setup reaction. The structure of the products was confirmed by FT-IR, (1)H NMR, and (13)C NMR spectra. The antibacterial activities of compounds 6a-d were screened against Escherichia coli, Micrococcus luteus, Pseudomonas aeruginosa, and Staphylococcus aureus bacterial strains using the zone inhibition method. Also, the 2,2-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activities of compounds 6a-d were evaluated. All compounds showed good antioxidant capacity in comparison to ascorbic acid. The IC50 values of the antioxidant activity were calculated. The proposed mechanism for antioxidant activity is discussed.

Topics: Anti-Bacterial Agents; Antioxidants; Ascorbic Acid; Bacteria; Biphenyl Compounds; Carbon-13 Magnetic Resonance Spectroscopy; Catalysis; Dihydropyridines; Disk Diffusion Antimicrobial Tests; Drug Design; Green Chemistry Technology; Molecular Structure; Picrates; Proton Magnetic Resonance Spectroscopy; Spectroscopy, Fourier Transform Infrared; Structure-Activity Relationship; Zinc

A 2,2-diphenyl-1-picrylhydrazyl radical (DPPH˙) was successfully solubilised in water by β-cyclodextrin (β-CD). DPPH˙/β-CD thus obtained was demonstrated to be a powerful tool to evaluate the antioxidative activity of water-soluble antioxidants, such as ascorbate and Trolox, in aqueous buffer solutions.

Topics: Ascorbic Acid; beta-Cyclodextrins; Biphenyl Compounds; Chromans; Free Radical Scavengers; Free Radicals; Picrates; Solubility; Water

Diabetes mellitus is a global health problem and constantly increasing day by day. The number of diabetic people in world is expected to rise to 366 million in 2030. The available drugs for diabetes, insulin or oral hypoglycemic agents have one or more side effects and search for new antidiabetic drugs with minimal or no side effects from medicinal plants is a challenging for us. The present study was undertaken to investigate the antidiabetic and antioxidant activity of Semecarpus anacardium (Linn.) (abbreviated as SF).. The antidiabetic activity was determined by using alloxan-induced diabetic rats. After 15 days of treatment, serum biochemical parameters such as TC, TG, LDL, HDL, SGOT and SGPT were estimated. The survival rate, body weight, organ weight, liver glycogen and blood parameters (RBC and Hb) were also measured. The antioxidant activity was measured by DPPH free radical scavenging assay. Phytochemical screening, total phenolic and total flavonoid content were determined by using standard methods.. The results showed that the survival rate was 100% in rats of Group SA 400. The effect of extract on blood glucose level in Groups SA 100, SA 200 and SA 400 were dose-dependent throughout the treatment period. No significant changes in organ weight to body weight ratio were observed, liver weights significantly improved in Groups SA 200 and SA 400. The bark extract exhibited significant (p < 0.05) anti-diabetic activity with lowering TC, TG, LDL level dose-dependently and protected liver which may be partially explained by attenuation of SGOT and SGPT levels and increases liver glycogen. The percentage of Hb and RBC counts were negatively correlated with the doses of extracts. In DPPH scavenging assay, IC50 values of SA extract and ascorbic acid were found 72.24 μg/ml and 17.81 μg/ml, respectively. Phytochemical screening showed the presence of steroids, triterpenoids, flavonoids, glycosides, saponins, and tannins that were contribute to biological activity.. These results indicated that stem barks of S. anacardium possess strong anti-diabetic and antioxidant potentials and support traditional medicinal use for the treatment of diabetes mellitus and good source for natural antioxidants.

Topics: Animals; Antioxidants; Ascorbic Acid; Biphenyl Compounds; Blood Glucose; Diabetes Mellitus, Experimental; Flavonoids; Hypoglycemic Agents; Insulin; Male; Phenols; Phytotherapy; Picrates; Plant Bark; Plant Extracts; Plant Stems; Rats; Rats, Wistar; Semecarpus

Products containing natural additives, including antioxidants, are usually perceived by consumers as safer than those with synthetic ones. Natural antioxidants, besides having a preservative activity, may exert beneficial health effects. Interactions between antioxidants may significantly change their antioxidant activity, thus in designing functional foods or food/cosmetic ingredients knowledge about the type of interactions could be useful. In the present study, the interactions between ascorbic acid (AA; vitamin C) and different black and green tea extracts and the influence on their antioxidant activities were investigated. The antioxidant activities of tea extracts and their mixtures with AA prepared in several different weight ratios were measured using the trolox equivalent antioxidant capacity (TEAC), 1,1-diphenyl-2-picrylhydrazyl (DPPH), and ferric-reducing antioxidant power (FRAP) methods. The type of interaction was determined by interaction indexes and isobolograms. It was found that the weight ratio of extracts to AA significantly influenced the antioxidant activity of a mixture and the type of interaction between these components. The weight ratio of tea extract to AA can cause the change of interaction, e.g. from antagonism to additivism or from additivism to synergism. The observed differences in the type of interactions were probably also a result of different extracts' polyphenol composition and content. The type of interaction may also be affected by the medium in which extracts and AA interact, especially its pH and the solvent used. To obtain the best antioxidant effect, all these factors should be taken into account during the design of a tea extract-AA mixture.

Topics: Antioxidants; Ascorbic Acid; Biphenyl Compounds; Camellia sinensis; Drug Interactions; Drug Synergism; Ferric Compounds; Functional Food; Hydrogen-Ion Concentration; Picrates; Plant Extracts; Plant Leaves; Polyphenols; Solvents; Tea

The present work was focused to evaluate in vitro antioxidant of Pleurotus florida. The hydroethanolic extract was prepared by macerating basidiocarp with water:ethanol (1:1). The antioxidant potential was evaluated by 1,1-diphenyl-2-picryl-hydrazyl (DPPH) radical scavenging activity, reducing power, chelating effects on ferrous ions, total antioxidant capacity, and lipid peroxidation inhibitory activity. Further total flavonoid and phenolic content was also estimated. The comparison between different antioxidant assays was done by correlation coefficient. The results from the antioxidant assays showed that hydroethanolic extract (HEE) might act as radical scavenger to a certain extent. The distinct scavenging activities of HEE can be due to the diverse phytochemical constituents. Being a rich source of antioxidants, P. florida can be used as an accessible source of natural antioxidants with consequential health benefits.

Topics: Antioxidants; Ascorbic Acid; Biphenyl Compounds; Ethanol; Ferrous Compounds; Flavonoids; Free Radical Scavengers; Fruiting Bodies, Fungal; India; Iron Chelating Agents; Lipid Peroxidation; Oxidation-Reduction; Phenols; Picrates; Pleurotus; Water

The objective of this study was to evaluate the effect of Curcuma longa powder and ascorbic acid on some quality traits of rabbit burgers. The burgers (burgers control with no additives; burgers with 3.5 g of turmeric powder/100g meat; burgers with 0.1g of ascorbic acid/100g meat) were analyzed at Days 0 and 7 for pH, color, drip loss, cooking loss, fatty acid profile, TBARS, antioxidant capacity (ABTS, DPPH and FRAP) and microbial growth. The addition of turmeric powder modified the meat color, produced an antioxidant capacity similar to ascorbic acid and determined a lower cooking loss than other formulations. Turmeric powder might be considered as a useful natural antioxidant, increasing the quality and extending the shelf life of rabbit burgers.

Topics: Animals; Antioxidants; Ascorbic Acid; Benzothiazoles; Biphenyl Compounds; Color; Cooking; Curcuma; Food Handling; Food Preservation; Food Preservatives; Food Storage; Humans; Meat; Meat Products; Picrates; Plant Extracts; Powders; Rabbits; Sulfonic Acids; Thiobarbituric Acid Reactive Substances; Water

This research aimed to compare antioxidant and anticancer activities of the essential oil from various habitats of Selaginella doederleinii Hieron. The results showed that antioxidative activities of the essential oil were the best from Guizhou province in 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging, 2,2'-azinobis-(3-ethylbenzthiazoline-6-sulphonate) (ABTS) radical scavenging, ferric reducing and ferric reducing antioxidant power (FRAP), while those of the essential oil from Sichuan province were the weakest among different habitats. The anticancer results showed that antitumor effects of the essential oil from Guizhou province were the best against A549 cell line and 7721 cell line, while those of the essential oil from Sichuan province were the weakest among different habitats. Proliferative and antioxidant activities were correlated. The correlation coefficients (R2) between antioxidant and anticancer capacities varied from 0.71 to 0.94. The results of tests indicated that the antioxidant and anticancer activities of the essential oil from various habitats were great differences that might be affected by environmental variation, harvest seasons and so on. Investigation in vitro revealed that the essential oil of S. doederleinii were found to be effective in suppressing the oxidative activity and proliferation of cancer cells. This experiment provides scientific foundation for further utilization of S. doederleinii.

Topics: Antineoplastic Agents; Antioxidants; Ascorbic Acid; Benzothiazoles; Biphenyl Compounds; Butylated Hydroxytoluene; Cell Line, Tumor; Cell Proliferation; Cisplatin; Ecosystem; Humans; Oils, Volatile; Picrates; Selaginellaceae; Sulfonic Acids; Tetrazolium Salts; Thiazoles

Dermacoccus abyssi sp. nov. strains MT1.1 and MT1.2 are actinomycetes isolated from a Mariana Trench sediment at a depth of 10 898 m. The fermentation process using complex media led to the production of three new pigmented heteroaromatic (oxidized and reduced) phenazine compounds, dermacozines H-J (1-3). Extensive use was made of 1D and 2D NMR experiments and high-resolution MS to determine the structures of the compounds. The new dermacozines showed radical scavenging activity, and the highest activity was observed for dermacozine H (1), with an IC50 value of 18.8 μM.

Topics: Actinomycetales; Biphenyl Compounds; DNA, Bacterial; Free Radical Scavengers; Geologic Sediments; Inhibitory Concentration 50; Molecular Structure; Nuclear Magnetic Resonance, Biomolecular; Oxidation-Reduction; Phenazines; Phylogeny; Picrates

Edible mushrooms are known as an important source of natural antioxidants. The ethyl acetate extract of the edible mushroom Sarcodon leucopus (Zangzi mushroom) possesses strong antioxidative activity. Bioactivity-guided isolation afforded 10 compounds from its fruiting bodies, including two new sarcoviolins, sarcoviolin β (1) and episarcoviolin β (2), and one new p-terphenyl derivative (3) along with seven known compounds. The structures of the new compounds were elucidated by spectroscopic methods and comparison with the known compounds. Compounds 1-10 were found to have antioxidant effects in the DPPH scavenging assay, the total antioxidant capacity assay, the reducing power assay, and the lipid peroxidation assay. Further study indicated that they could protect DNA strands from free radical-induced cleavage at 200 μM. Compounds 1-10 also presented strong α-glucosidase inhibitory activity. Of all tested compounds, compound 1 exhibited the strongest inhibitory activity, with an IC50 value of 0.58 μM.

Topics: Agaricales; Antioxidants; Biphenyl Compounds; Free Radical Scavengers; Glycoside Hydrolase Inhibitors; Inhibitory Concentration 50; Lipid Peroxidation; Molecular Structure; Picrates; Terpenes; Terphenyl Compounds; Tibet

Two rare 7,8-seco-lignans (1, 2), three new lignan glycosides (3, 4a, 4b), and 10 known lignans (5-14) were isolated from the fruit of Schisandra glaucescens Diels. The absolute configurations of 1 and 2 were determined by comparing their experimental and calculated electronic circular dichroism spectra. The molecular structures of the new compounds (3, 4a, and 4b), including their absolute configurations, were determined using various spectroscopic methods and hydrolysis reactions. The antioxidant activities of the isolated compounds were tested using 2,2-diphenyl-1-picrylhydrazyl and ferric reducing antioxidant power assays. Compounds 4, 7, 8, 10, 11, and 12 exhibited antioxidant activities of varying potential in both assays. Of these compounds, 7 showed the strongest 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging capacity, with IC50 values of 15.7 (150 μM DPPH) and 34.6 μM (300 μM DPPH), respectively, and 4, 12, and 7 displayed higher total antioxidant activities than Trolox in the ferric reducing antioxidant power assay. The neuroprotective effects of these compounds against Aβ25-35-induced cell death in SH-SY5Y cells were also investigated. Compounds 1, 2, 6, 7, 8, 11, and 12 exhibited statistically significant neuroprotective effects against Aβ25-35-induced SH-SY5Y cell death compared with the group treated only with Aβ25-35.

Topics: Amyloid beta-Peptides; Antioxidants; Biphenyl Compounds; Chromans; Drugs, Chinese Herbal; Fruit; Glycosides; Inhibitory Concentration 50; Lignans; Molecular Structure; Neuroprotective Agents; Nuclear Magnetic Resonance, Biomolecular; Oxidation-Reduction; Peptide Fragments; Picrates; Plant Extracts; Schisandra

A new chlorinated pentacyclic polyketide, daldinone E (1), was purified from a Daldinia sp. fungal isolate treated with the epigenetic modifier suberoylanilide hydroxamic acid (SAHA). A biosynthetically related epoxide-containing daldinone analogue, 2, was also purified from the same fungus. The structures of both compounds were established by spectroscopic methods, and the absolute configurations were assigned by analysis of their NMR data (coupling constants and ROESY correlations) and DFT calculations of specific rotations and ECD spectra. During the course of these studies it was determined that metabolite 2 and the previously reported daldinone B shared the same spectroscopic data, leading to a revision of the reported structure. Both compounds 1 and 2 also exhibited DPPH radical scavenging activities with potency comparable to the positive control ascorbic acid.

Topics: Biphenyl Compounds; Free Radical Scavengers; Histone Deacetylase Inhibitors; Hydrocarbons, Chlorinated; Hydroxamic Acids; Klebsiella pneumoniae; Methicillin-Resistant Staphylococcus aureus; Microbial Sensitivity Tests; Molecular Structure; Nuclear Magnetic Resonance, Biomolecular; Picrates; Polyketides; Vorinostat; Xylariales

A variety of bis heterocycles, oxazolyl/thiazolyl/imidazolyl oxadiazoles having a styryl sulfonylmethyl group at the 5-position of oxadiazole and tris heterocycles having a pyrrolyl/pyrazolyl sulfonylmethyl group at the 5-position of oxadiazole were prepared adopting simple and versatile synthetic methodologies. All the compounds were screened for their antioxidant activities. Compound 5b displayed radical scavenging activity in all the three methods greater than the standard ascorbic acid, whereas compounds 8b and 14b showed activities equal to the standard ascorbic acid.

Topics: Ascorbic Acid; Benzothiazoles; Biphenyl Compounds; Drug Design; Free Radical Scavengers; Heterocyclic Compounds; Molecular Structure; Nitric Oxide; Picrates; Structure-Activity Relationship; Sulfonic Acids

In this study, firstly, antioxidant and polyphenol oxidase (PPO) properties of Yomra apple were investigated. Seventeen phenolic constituents were measured by reverse phase-high-performance liquid chromatography (RP-HPLC). Total phenolic compounds (TPCs), ferric reducing antioxidant power (FRAP) and 2, 2-diphenyl-1-picrylhydrazyl radical (DPPH) scavenging activities were performed to measure antioxidant capacity. Some kinetic parameters (Km, Vmax), and inhibition behaviors against five different substrates were measured in the crude extract. Catechin and chlorogenic acid were found as the major components in the methanolic extract, while ferulic acid, caffeic acid, p-hydroxybenzoic acid, quercetin and p-coumaric acid were small quantities. Km values ranged from 0.70 to 10.10 mM in the substrates, and also 3-(4-hydroxyphenyl) propanoic acid (HPPA) and L-DOPA showed the highest affinity. The inhibition constant of Ki were ranged from 0.05 to 14.90 mM against sodium metabisulphite, ascorbic acid, sodium azide and benzoic acid, while ascorbic acid and sodium metabisulphite were the best inhibitors.

Topics: Antioxidants; Ascorbic Acid; Biphenyl Compounds; Caffeic Acids; Catechin; Catechol Oxidase; Chlorogenic Acid; Coumaric Acids; Enzyme Inhibitors; Fruit; Kinetics; Levodopa; Malus; Oxidation-Reduction; Parabens; Phenylpropionates; Picrates; Plant Extracts; Plant Proteins; Polyphenols; Propionates; Quercetin; Sulfites

Genipin, the multipotent ingredient in Gardenia jasmenoides fruit extract (GFE), may be an effective candidate for treatment following stroke or traumatic brain injury (TBI). Secondary injury includes damage mediated by reactive oxygen species (ROS) and reactive nitrogen species (RNS), which can alter the biological function of key cellular structures and eventually lead to cell death. In this work, we studied the neuroprotective potential of genipin against damage stemming from ROS and RNS production in organotypic hippocampal slice cultures (OHSC), as well as its potential as a direct free radical scavenger. A 50 µM dose of genipin provided significant protection against tert-butyl hydroperoxide (tBHP), a damaging organic peroxide. This dosage of genipin significantly reduced cell death at 48 h compared to vehicle control (0.1% DMSO) when administered 0, 1, 6, and 24 h after addition of tBHP. Similarly, genipin significantly reduced cell death at 48 h when administered 0, 1, 2, and 6h after addition of rotenone, which generates reactive oxygen species via a more physiologically relevant mechanism. Furthermore, genipin significantly reduced both cell death and nitrite levels at 24 h caused by S-nitroso-N-acetylpenicillamine (SNAP), a direct nitric oxide (NO) donor, and successfully quenched 1,1-Diphenyl-2-picryl-hydrazyl (DPPH), a stable free radical, suggesting that genipin may act as a direct free radical scavenger. Our encouraging findings suggest that genipin should be tested in animal models of CNS injury with a significant component of ROS- and RNS-mediated damage, such as TBI and stroke, to assess its in vivo efficacy.

Topics: Analysis of Variance; Animals; Animals, Newborn; Ascorbic Acid; Biphenyl Compounds; Cell Death; Dose-Response Relationship, Drug; Hippocampus; Insecticides; Iridoids; Neuroprotective Agents; Nitric Oxide Donors; Organ Culture Techniques; Picrates; Reactive Nitrogen Species; Reactive Oxygen Species; Rotenone; S-Nitroso-N-Acetylpenicillamine; Time Factors

Loess Plateau is a typical rain-fed farming region, facing the threat of drought. Irrigation method is among the most important factors affecting jujube quality. This study investigated the response of Ziziphus jujuba Mill. cv. Lizao quality to three different irrigation methods (drip-, pipe- and surge spring root irrigation) combining two water levels (20 m(3)/hm(2) and 120 m(3)/hm(2)). The effects of the trials were evaluated by taking into account the physical-chemical characteristics of jujubes and the antioxidant activity. Concomitant to this, the concentration of some taste-related (viz. glucose, fructose, TSS and malic acid) and health-related compounds/parameters (viz. catechin and epicatechin) were generally much greater in jujube fruit treated with drip irrigation (120 m(3)/hm(2)). Different irrigation treatments had no significant effects on antioxidant capacity, total phenolics and proanthocyanidins (except for pipe irrigation 20 m(3)/hm(2)). The best compromise between quality and irrigation of jujube fruit was achieved with drip irrigation (120 m(3)/hm(2)).

Topics: Agricultural Irrigation; Antioxidants; Ascorbic Acid; Benzothiazoles; Biomass; Biphenyl Compounds; Carbohydrates; Carboxylic Acids; China; Ecosystem; Fruit; Humidity; Phenols; Picrates; Plant Roots; Proanthocyanidins; Solubility; Sulfonic Acids; Water Supply; Ziziphus

The chelation behavior of N-{[(allylamino) thiomethyl] hydrazinocarbonylmethyl} trimethylammonium chloride (H3ATHC) towards VO(2+), Co(2+), Ni(2+), Cu(2+), Zn(2+) and UO2(2+) ions have been studied. The structures of the complexes were elucidated using elemental analyses, spectral (IR, UV-visible, (1)H NMR and ESR and mass) as well as magnetic and thermal measurements. The ligand acted as ON bidentate, ONS tridentate donor forming mononuclear complexes. A tetrahedral geometry for Co(2+), square-planar for Ni(2+) and Cu(2+), an octahedral for Zn(2+) and a square-pyramidal arrangement for VO(2+) complexes were proposed, respectively. The EPR spectra of Cu(2+) and VO(2+) complexes confirmed the suggested geometries with values of α(2) and β(2) indicating that the in-plane σ-bonding and in-plane π-bonding are appreciably covalent, and were consistent with very strong in-plane σ bonding in the complexes. Also, the bond length, bond angle, HOMO, LUMO, dipole moment and charges on the atoms have been calculated. Also, the thermal behavior and kinetic parameters were determined using Coats-Redfern and Horowitz-Metzger methods. Furthermore, the synthesized compounds were screened for their superoxide-scavenging activity in the PMS/NADH-NBT system as well as their scavenging effect on ABTS (2,2'-azino-bis(3-ethyl benzthiazoline-6-sulfonic acid) and 2,2-diphenyl-1-picrylhydrazyl(DPPH) radicals. Among these compounds, the ligand and Zn(2+) complex, exhibited the potent ABTS (2,2'-azino-bis(3-ethyl benzthiazoline-6-sulfonic acid) radical scavenging activity, comparable to that of vitamin C.

Topics: Antioxidants; Ascorbic Acid; Benzothiazoles; Biphenyl Compounds; Cations, Divalent; Metals; Models, Chemical; Models, Molecular; Picrates; Semicarbazides; Sulfonic Acids

The Stewartia koreana Nakai (SK) had been used in oriental traditional medicine as a remedy for acute gastroenteritis, liver diseases, quadriplegia and pain. The antioxidant activity guided isolation 80% methyl extract from stems of SK yielded eight phenolic compounds. We evaluated the anti-oxidative and anti-inflammatory effects of these compounds via assays of 1,1-diphenyl-2-picrylhydazyl (DPPH) radicals and inhibition of nitric oxide (NO) production in lipopolysaccharide-stimulated RAW 264.7 macrophage cells. The results demonstrated that syringaresinol (6) exhibited significant DPPH radical-scavenging activity and inhibitory effects on NO production compared with its positive controls, ascorbic acid and L-NMMA, respectively.

Topics: Animals; Anti-Inflammatory Agents; Antioxidants; Ascorbic Acid; Biphenyl Compounds; Free Radical Scavengers; Furans; Lignans; Lipopolysaccharides; Macrophages; Mice; Molecular Structure; Nitric Oxide; omega-N-Methylarginine; Oxidation-Reduction; Phenols; Picrates; Plant Stems; Theaceae

Ellagic acid (EA, C14H6O8) is a natural dietary polyphenol whose benefits in a variety of diseases shown in epidemiological and experimental studies involve anti-inflammation, anti-proliferation, anti-angiogenesis, anticarcinogenesis and anti-oxidation properties. In vitro radical scavenging and antioxidant capacity of EA were clarified using different analytical methodologies such as total antioxidant activity determination by ferric thiocyanate, hydrogen peroxide scavenging, 1,1-diphenyl-2-picryl-hydrazyl free radical (DPPH) scavenging, 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) radical scavenging activity and superoxide anion radical scavenging, ferrous ions (Fe2+) chelating activity and ferric ions (Fe3+) reducing ability. EA inhibited 71.2% lipid peroxidation of a linoleic acid emulsion at 45 μg/mL concentration. On the other hand, butylated hydroxytoluene (BHT), butylated hydroxyanisole (BHA), α-tocopherol and ascorbic acid displayed 69.8%, 66.8%, 64.5% and 59.7% inhibition on the peroxidation of linoleic acid emulsion at the same concentration, respectively. In addition, EA had an effective DPPH• scavenging, ABTS+ scavenging, superoxide anion radical scavenging, hydrogen peroxide scavenging, ferric ions (Fe3+) reducing power and ferrous ions (Fe2+) chelating activities. Also, those various antioxidant activities were compared to BHA, BHT, α-tocopherol and ascorbic acid as references antioxidant compounds. These results suggested that EA can be used in the pharmacological, food industry and medicine because of these properties.

Topics: alpha-Tocopherol; Antioxidants; Ascorbic Acid; Biphenyl Compounds; Butylated Hydroxyanisole; Butylated Hydroxytoluene; Chelating Agents; Ellagic Acid; Emulsions; Free Radical Scavengers; Free Radicals; Hydrogen Peroxide; Iron; Linoleic Acid; Lipids; Oxygen; Picrates; Spectrophotometry; Superoxides; Thiocyanates; Time Factors

In the present study the structure of proanthocyanidins from Polyalthia longifolia leaves was characterized with (13)C nuclear magnetic resonance, high performance liquid chromatography electrospray ionization mass spectrometry, and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry analyses. The results showed that the proanthocyanidins were mixture of homopolymers of B-type procyanidins with degree of polymerization up to 14-mer. Furthermore, the antioxidant activity of the proanthocyanidins was studied through 2,2-diphenyl-1-picrylhydrazyl and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) free-radical scavenging activities, and ferric reducing/antioxidant power assays. In addition, antityrosinase activity of the proanthocyanidins was investigated. The IC50 for 2,2-diphenyl-1-picrylhydrazyl and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) free-radical scavenging activity of the proanthocyanidins were 89.32 ± 12.07 and 76.79 ± 5.88 μg/mL, respectively; the ferric reducing/antioxidant power value was 710.54 ± 142.82 mg ascorbic acid equivalent/g dry weight. The IC50 for antityrosinase activity was 773.09 ± 1.47 μg/mL. In conclusion, the proanthocyanidins from P. longifolia leaves exhibited potent antioxidant and antityrosinase activities. This research would provide scientific evidence for the use of proanthocyanidins from P. longifolia leaves as antioxidant and antityrosinase agents.

Topics: Antioxidants; Ascorbic Acid; Benzothiazoles; Biflavonoids; Biphenyl Compounds; Catechin; Chromatography, High Pressure Liquid; Enzyme Inhibitors; Free Radical Scavengers; Inhibitory Concentration 50; Magnetic Resonance Spectroscopy; Monophenol Monooxygenase; Oxidation-Reduction; Picrates; Plant Leaves; Polyalthia; Proanthocyanidins; Reducing Agents; Spectrometry, Mass, Electrospray Ionization; Sulfonic Acids

The objective of this study was to investigate the antioxidant and antibacterial activities of exopolysaccharide (EPS) from Bifidobacterium bifidum WBIN03 (B-EPS) and Lactobacillus plantarum R315 (L-EPS). The 1,1-diphenyl-2-picrylhydrazyl (DPPH)-radical scavenging, hydroxyl radical-scavenging, and superoxide radical-scavenging abilities were measured to evaluate antioxidant activity. Inhibition of erythrocyte hemolysis and lipid peroxidation was also measured. Both B-EPS and L-EPS had strong scavenging ability against DPPH and superoxide radicals at high concentration. The inhibitory effect of B-EPS on erythrocyte hemolysis was stronger than that of L-EPS in a concentration range from 0.30 to 1.00 mg/mL, whereas the hydroxyl scavenging ability of L-EPS (39.15 ± 0.58%) was significantly higher than that of 0.15 mg/mL ascorbic acid (24.33 ± 1.17%) and B-EPS (17.89 ± 3.30%) at 0.10 mg/mL. The inhibition of lipid peroxidation of 0.50 mg/mL B-EPS and L-EPS was 13.48 ± 1.74% and 12.43 ± 0.51%, respectively, values lower than that of ascorbic acid at the same concentration (23.20 ± 1.41%). Furthermore, all these abilities were enhanced in a concentration-dependent manner. Agar diffusion assay showed that both EPS exhibited antibacterial activities against tested pathogens such as Cronobacter sakazakii, Escherichia coli, Listeria monocytogenes, Staphyloccocus aureus, Candida albicans, Bacillus cereus, Salmonella typhimurium, and Shigella sonnei at 300 μg/mL. In conclusion, both EPS have antimicrobial and antioxidant activities and could have applications in the food industry.

Topics: Anti-Bacterial Agents; Anti-Infective Agents; Antioxidants; Ascorbic Acid; Bifidobacterium; Biphenyl Compounds; Lactobacillus plantarum; Lipid Peroxidation; Oxidation-Reduction; Picrates; Polysaccharides, Bacterial

Polyphenols are functional compounds in plants, which possess many bioactivities beneficial for humans. The aim of this study was to establish a highly efficient method for extracting polyphenol compounds from areca seeds and further to identify polyphenols and antioxidant properties of the seeds. A quadratic general rotary unitized design was used to determine the optimal extraction process. The polyphenols were identified using LC-TOF-MS. By comparison with ascorbic acid (Vc), the antioxidant activities of the ethanol extracts were evaluated using three complementary in vitro assays: inhibition of the DPPH (1,1-diphenyl-2-picrylhydrazyl) radical-scavenging activity, hydroxyl radical-scavenging activity, and reducing ability. The two major polyphenols obtained were epicatechin and syringic acid. The ethanol extracts of areca seeds showed significantly greater antioxidant activity (p < 0.05) than Vc using the DPPH and reducing power assay, but lower ability (p < 0.05) using the hydroxyl radical assay. The results indicate that the areca seed is an excellent food material with potential antioxidant properties.

Topics: Antioxidants; Areca; Ascorbic Acid; Biphenyl Compounds; Catechin; Chromatography, Liquid; Gallic Acid; Mass Spectrometry; Picrates; Polyphenols; Seeds

In this study, we evaluated total phenolics, condensed tannins, ascorbic acid, lycopene, β-carotene, total antioxidant activity, reducing power, ferric-reducing antioxidant power, and radical scavenging activity (RSA) on ABTS and DPPH as well as metal chelating activity of methanolic and aqueous extract from caps and stipes of Calocybe indica and Pleurotus sajor-caju mushrooms. Per gram of extract, the different mushroom extracts contained 18.09-27.47 mg gallic acid equivalent of phenolics, 5.06-8.89 mg catechins of tannins, and 0.15-0.21 mg ascorbic acid. Principal component analysis (PCA) revealed that methanolic extract from caps of C. indica and P. sajor-caju contained higher ascorbic acid, total antioxidant activity, β-carotene and radical scavenging activity (RSA) on 2,2-diphenyl-1-picrylhydrazyl (DPPH) than did the stipes. The aqueous extract from cap and stipe of P. sajor-caju had higher total phenolics and RSA on 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulphonic acid) (ABTS) as well as higher metal-chelating activity and ferric-reducing antioxidant power. The antioxidant potential is higher in the caps of P. sajor-caju and C. indica than in the stipes; the cap contributes most to antioxidant activity.

Topics: Antioxidants; Ascorbic Acid; Basidiomycota; Benzothiazoles; beta Carotene; Biphenyl Compounds; Carotenoids; Chelating Agents; Fluorescence Recovery After Photobleaching; India; Lycopene; Picrates; Polyphenols; Sulfonic Acids; Tannins

Xanthine oxidase (XO) generates superoxide anions and H(2)O(2) for the self-defence system of organism. Abnormal production of this superoxide's (reactive oxygen species) is responsible for a number of complications including inflammation, metabolic disorder, cellular aging, reperfusion damage, atherosclerosis and carcinogenesis. Series of novel trisubstituted thiophenyl-1-thiazolyl-2-pyrazoline libraries are synthesized containing 2,5-dichloro thiophene, 5-chloro-2-(benzylthio) thiophene and 5-chlorothiophene-2-sulphonamide, from chalcones in PEG-400 as green solvent. Superoxide (XO) inhibitory and free radical scavenging activities were also figured out with molecular modeling analysis, bearing in mind their possible future for super oxide inhibitor (Gout) therapeutics, compound 3k shows interesting superoxide inhibitory and free radical scavenger activity with IC(50)=6.2 μM, in comparison with allopurinol.

Topics: Animals; Biphenyl Compounds; Free Radical Scavengers; Green Chemistry Technology; Molecular Docking Simulation; Picrates; Polyethylene Glycols; Rats; Rats, Wistar; Reactive Oxygen Species; Superoxides; Thiophenes; Xanthine Oxidase

A novel series of compounds were synthesized by cyclic condensation reaction of substituted isothiocyanate (2a-c) with 2-thiophenecarboxylic acid hydrazide (1) in the presence of ethyl alcohol, to obtain intermediate thiosemicarbazides (3a-c), which were further treated with sodium hydroxide in the presence of ethanol to obtain triazole derivatives (4a-c). The latter were refluxed with substituted secondary amines and formaldehyde for 6-10 h to afford Mannich bases (5a-k). The synthesized compounds were characterized on the basis of their spectral (IR, (13)C and (1)H NMR) data and evaluated for biological activities. Some of the compounds were found to exhibit significant antimicrobial and antioxidant activity.

Topics: Anti-Bacterial Agents; Antifungal Agents; Antioxidants; Aspergillus flavus; Aspergillus fumigatus; Biphenyl Compounds; Dose-Response Relationship, Drug; Escherichia coli; Free Radical Scavengers; Microbial Sensitivity Tests; Models, Chemical; Molecular Structure; Oxidation-Reduction; Penicillium; Picrates; Staphylococcus aureus; Thiones; Triazoles; Trichophyton

The chemical behavior of 4-(dimethylaminomethylene)-1-phenyl-3-(pyridin-3-yl)-1H-pyrazol-5(4H)-one (enaminone) (2) toward some active methylene reagents has been reported to give pyrazolopyridine derivatives. All the reactions were carried out by conventional heating and microwave irradiation technique. The antioxidant activity of the prepared compounds was studied using 1,1-phenyl-2-picrylhydrazyl (DPPH) assay. Compounds (4c) and (4d) showed the highest activity. The antitumor activity against liver and breast cell lines was tested. Compounds (6), (9) and (11) showed the highest activity for liver cell line while compounds (6) and (9) showed the highest activity for breast cell line. Compounds (4a-d) were screened for their antibacterial activity against Gram-positive, Gram-negative bacteria and antifungal activity.

Topics: Anti-Infective Agents; Antineoplastic Agents; Bacteria; Biphenyl Compounds; Cell Line, Tumor; Chemistry Techniques, Synthetic; Free Radical Scavengers; Humans; Microwaves; Picrates; Pyrazoles; Pyridines

Five new hispidin derivatives, phaeolschidins A-E (1-5), as well as two known natural products, pinillidine (6) and hispidin (7), were isolated from the fruiting bodies of Phaeolus schweinitzii collected in the Tibetan Plateau. The structures of the new compounds were elucidated by spectroscopic methods. Phaeolschidins A-D (1-4) are new bishispidins. Phaeolschidin E (5) is a new class of hispidin derivative in which one pyrrolidin-2-one moiety was linked to C-3 of hispidin. The antioxidant activity of 1-7 was evaluated using three methods: the DPPH scavenging assay, the total antioxidant capacity assay, and the lipid peroxidation assay. Hispidin showed the strongest antioxidant activity of all tested compounds. This is the first report of secondary metabolites from the fungus P. schweinitzii.

Topics: Agaricales; Antioxidants; Biphenyl Compounds; Fruiting Bodies, Fungal; Lipid Peroxidation; Molecular Structure; Oxidation-Reduction; Picrates; Pyrones; Tibet

A series of 6-aryl-5-cyano thiouracil derivatives (2a-c to 11a-c) was synthesized from 6-aryl-4-hydrazino-2-thioxo-1,2-dihydropyrimidine-5-carbonitriles (1a-c). The products were characterized by analytical and spectral data (IR, (1)H NMR, (13)C NMR and mass spectra). All compounds were screened for their in-vitro antibacterial and antifungal activities. Compounds 7a, 7g and 9a-c showed pronounced antimicrobial activity than standards. Some of the newly synthesized compounds were evaluated for antioxidant activity. Compounds 1c, 5c and 8c displayed promising free radical scavenging activity and found to be more potent than standard, ascorbic acid (vitamin C).

Topics: Anti-Bacterial Agents; Antifungal Agents; Antioxidants; Bacteria; Biphenyl Compounds; Dose-Response Relationship, Drug; Free Radical Scavengers; Fungi; Microbial Sensitivity Tests; Molecular Structure; Picrates; Structure-Activity Relationship; Thiouracil

Previously, we have meticulously examined the efficacy of the measurable antimicrobial activity of sweet cherry (Prunus avium) extracts on a wide spectrum of gram-positive and gram-negative bacteria, in addition to the fungus, Candida albicans, a priori. In order to further understand the biochemical constituents and antioxidant activities of a variety of extracts of sweet cherries, antioxidant compounds of immunological significance, including L-ascorbic acid (vitamin C), phenols, flavonoids, and anthocyanins, and the total antioxidant (free radical scavenging) activity were simultaneously measured under varying and versatile extraction conditions (mild heating [5, 10 and 20 min.], and brief microwave exposure [1, 2 and 5 min.]) for a variety of extracts: i) whole juice extracts (WJE), ii) methanol-extracted juice (MEJ), iii) ddH2O-extracted pomace (dPOM), and iv) methanol-extracted pomace (mPOM). The antioxidant activity under the versatile extraction conditions adopted in this study was conspicuously reduced, such that the % inhibition against 2,2- diphenyl-1-picrylhydrazyl (DPPH) followed an inverse, negative correlational trendline. Moreover, ascorbic acid content was not affected with mild to prolonged heating or microwave exposure, except tangibly with dPOM and mPOM. The total phenols content assessed showed no significant variations, as compared with control extracts. In a manner similar to ascorbic acid, total flavonoids were mildly reduced under varying conditions, an effect mimicked to a certain extent with anthocyanins. Assessment of extraction means as compared with WJE revealed sharp decrease in the antioxidant activity for dPOM and mPOM, significant increase in L-ascorbic acid, total phenol, and flavonoid contents for MEJ, dPOM, and mPOM, and mild decrease in anthocyanin contents for dPOM and mPOM. These results confirm the measurable antioxidant activities and contents of P. avium extracts under versatile conditions of mild exposure, an effect bearing significant biochemical properties of a variety of extraction methods. Further studies are currently investigating the effect of specific antioxidants of P. avium on microbial growth in vitro per se. Since many of the aforementioned molecules hold immunobiochemical constituencies, antioxidant compounds in sweet cherries may have putative anti-inflammatory potential in medicinal chemistry, corroborating the observation of regulating/attenuating the growth of microorganisms of medical importanc

Topics: Anthocyanins; Antioxidants; Ascorbic Acid; Biphenyl Compounds; Dose-Response Relationship, Drug; Flavonoids; Hot Temperature; Phenols; Picrates; Plant Extracts; Prunus

Mushrooms have long been treated as a delicacy. Nowadays, however, many researchers consider them to be nutraceutical foods. The objective of this study was to determine the nutraceutical components in 7 edible species of Termitomyces (T. microcarpus, T. radicatus, T. badius, T. medius, T. heimii, T. striatus, and T. mammiformis) collected from different localities in North India during the monsoon season; their antioxidant properties also were determined by DPPH free radical scavenging ability and reducing power ability. The various nutraceutical components evaluated include phenolics (15.0-25.85 mg/g), flavonoids (1.38-2.02 mg/g), ascorbic acid (0.018-0.15 mg/g), β-carotene (0.11-0.27 µg/g), and lycopene (0.03-0.19 µg/g).

Topics: Agaricales; Antioxidants; Ascorbic Acid; Biphenyl Compounds; Dietary Supplements; India; Picrates; Species Specificity

Retrospectively, we have measured the antioxidant activity and a variety of antioxidant compounds under versatile extraction conditions of sweet cherry (Prunus avium) extracts. Further in this study, in order to understand the biochemical constituents and antioxidant activities of a variety of extracts of black sour cherries (P. cerasus), a related species, antioxidant compounds, including L-ascorbic acid (vitamin C), phenols, flavonoids, and anthocyanins, and the total antioxidant activity were simultaneously measured under varying extraction conditions (mild heating and brief microwave exposure) for: i) whole juice extracts (WJE), ii) methanol-extracted juice (MEJ), iii) ddH2O-extracted pomace (dPOM), and iv) methanol-extracted pomace (mPOM). The antioxidant activity for WJE was substantially increased with mild and prolonged exposure to either heating or microwave, such that the % inhibition against 2,2-diphenyl-1-bspicrylhydrazyl (DPPH) followed a positive correlation (heating, 5-20 min.; microwave, 1-2 min.), insignificant with MEJ and dPOM, whereas with mPOM there was sharp downregulation. L-Ascorbic acid content was not affected with mild to prolonged heating or microwave exposure (WEJ and mPOM), except a mild increase with MEJ and dPOM. Similarly, total phenols assessed showed no significant variations, as compared with control extracts, except a mild decrease with exposure for mPOM. In a manner similar to L-ascorbic acid, total flavonoid content was increased under varying conditions for WEJ and MEJ, and slightly decreased for dPOM and mPOM. On the other hand, anthocyanins showed differential variations with exposure (up- and downregulation). Assessment of extraction means as compared with WJE revealed sharp increase in the antioxidant activity for MEJ, dPOM and mPOM, significant increase in L-ascorbic acid, total phenol, and flavonoid contents for MEJ, dPOM and mPOM, and mild decrease in anthocyanin contents for MEJ, dPOM, and mPOM. These results substantiate the measurable antioxidant activities and contents of P. cerasus extracts under versatile conditions of mild exposure, an effect bearing significant fluctuation with biochemical properties. Since many of those molecules are known to have immuno-biochemical constituencies, antioxidant compounds in sour cherries may have putative antiinflammatory potential and applications in medicinal chemistry, corroborating the observation of regulating and attenuating the growth of microorganisms of medic

Topics: Anthocyanins; Antioxidants; Ascorbic Acid; Biphenyl Compounds; Dose-Response Relationship, Drug; Flavonoids; Hot Temperature; Phenols; Picrates; Plant Extracts; Prunus

The therapeutic action of a plant depends on its chemical constituents. In this study, experiments were carried out in order to evaluate the effect of extraction conditions on the antioxidative and antimicrobial activities of Roselle (Hibiscus sabdariffa L.).. Roselle was found to be rich in malic acid, anthocyanins, ascorbic acid and minerals, especially Ca and Fe, but low in glucose. More than 18 volatile compounds were identified by gas chromatography and gas chromatography-mass spectrometry. This herb, which is rich in phenolic compounds and displays DPPH radical scavenging activity, could be a good source of natural antioxidants. The antimicrobial activity of the Roselle water and ethanol extracts was tested with Bacillus subtilis (ATCC6633), Staphylococcus aureus (ATCC6538) and Escherichia coli (ATCC 8739). The inhibition of the Roselle ethanol extract against B. subtilis and S. aureus was slightly higher than that of water extract but this difference was not significant. However, E. coli was strongly inhibited by the Roselle water extract at concentrations of 25 and 50 mg mL(-1) as determined by a paper disc method.. The obtained results indicated that antioxidant and antimicrobial activity was related to different methods of extraction and Roselle extracts could be a source of therapeutically useful products.

Topics: Anthocyanins; Anti-Bacterial Agents; Antioxidants; Ascorbic Acid; Bacillus; Bacteria; Biphenyl Compounds; Escherichia coli; Hibiscus; Malates; Minerals; Oils, Volatile; Phenols; Picrates; Plant Extracts; Staphylococcus aureus

A new class of acetamidomethylsulfonyl bis heterocycles-oxazolyl-1,3,4-oxadiazoles, -thiazolyl-1,3,4-oxadiazoles, and -imidazolyl-1,3,4-oxadiazoles were synthesized from the synthetic intermediates, methyl 2-((4-aryloxazol-2-ylcarbamoyl)methylsulfonyl)acetate, methyl 2-((4-arylthiazol-2-ylcarbamoyl)methylsulfonyl)acetate, and methyl 2-((4-aryl-1H-imidazol-2-ylcarbamoyl)methylsulfonyl)acetate. All the title compounds were tested for their antioxidant activity. The oxadiazolylmethylsulfonyloxazolylacetamide displayed excellent radical-scavenging activity when compared with the standard ascorbic acid.

Topics: Antioxidants; Ascorbic Acid; Benzothiazoles; Biphenyl Compounds; Imidazoles; Molecular Structure; Nitric Oxide; Oxadiazoles; Picrates; Structure-Activity Relationship; Sulfonic Acids

Water-soluble corn silk polysaccharides (CSPS) were chemically modified to obtain their sulfated, acetylated and carboxymethylated derivatives. Chemical characterization and bioactivities of CSPS and its derivatives were comparatively investigated by chemical methods, gas chromatography, gel filtration chromatography, scanning electron microscope, infrared spectroscopy and circular dichroism spectroscopy, scavenging DPPH free radical assay, scavenging hydroxyl radical assay, ferric reducing power assay, lipid peroxidation inhibition assay and α-amylase activity inhibitory assay, respectively. Among the three derivatives, carboxylmethylated polysaccharide (C-CSPS) demonstrated higher solubility, narrower molecular weight distribution, lower intrinsic viscosity, a hyperbranched conformation, significantly higher antioxidant and α-amylase inhibitory abilities compared with the native polysaccharide and other derivatives. C-CSPS might be used as a novel nutraceutical agent for human consumption.

Topics: alpha-Amylases; Animals; Ascorbic Acid; Biphenyl Compounds; Enzyme Inhibitors; Free Radical Scavengers; Hydroxyl Radical; Iron; Lipid Peroxidation; Molecular Weight; Oxidation-Reduction; Picrates; Polysaccharides; Swine; Viscosity; Zea mays

A study was conducted to compare secondary metabolites and antioxidant activity of Labisia pumila Benth (Kacip Fatimah) in response to two sources of fertilizer [i.e., organic (chicken dung; 10% N:10% P₂O₅:10% K₂O) and inorganic fertilizer (NPK green; 15% N, 15% P₂O₅, 15% K₂O)] under different N rates of 0, 90, 180 and 270 kg N/ha. The experiment was arranged in a randomized complete block design replicated three times. At the end of 15 weeks, it was observed that the application of organic fertilizer enhanced the production of total phenolics, flavonoids, ascorbic acid, saponin and gluthathione content in L. pumila, compared to the use of inorganic fertilizer. The nitrate content was also reduced under organic fertilization. The application of nitrogen at 90 kg N/ha improved the production of secondary metabolites in Labisia pumila. Higher rates in excess of 90 kg N/ha reduced the level of secondary metabolites and antioxidant activity of this herb. The DPPH and FRAP activity was also highest at 90 kg N/ha. The results indicated that the use of chicken dung can enhance the production of secondary metabolites and improve antioxidant activity of this herb.

Topics: Animals; Ascorbic Acid; Biphenyl Compounds; Chickens; Feces; Fertilizers; Flavonoids; Free Radical Scavengers; Free Radicals; Glutathione; Nitrates; Phenols; Phytochemicals; Picrates; Primulaceae; Saponins

Increasing demand for more jujube (Ziziphus jujube Mill.) production requires understanding the specific fertilization needs of jujube trees. This study was conducted to compare fruit yields, phenolic profiles and antioxidant activity of jujube in response to different fertilizers. Application of organic fertilizer appeared to enhance the phenolics and antioxidant activity accumulation of jujubes, compared to conventional fertilized jujubes. Amongst inorganic fertilizers, supplemental potassium as an individual nutrient improved the accumulation of phenolics in jujubes. Our results demonstrate that phenolics levels and antioxidant activity of jujube can be manipulated through fertilizer management and tracked by following proanthocyanidin concentrations. In a practical production context, the combination of organic fertilizers and inorganic fertilizers such as more supplemental individual potassium, and less supplemental individual nitrogen and phosphorus, might be the best management combination for achieving higher phenolic concentration, stronger antioxidant activity and a good harvest.

Topics: Ascorbic Acid; Benzothiazoles; Biphenyl Compounds; Fertilizers; Flavonoids; Free Radical Scavengers; Free Radicals; Fruit; Oxidation-Reduction; Phenols; Picrates; Proanthocyanidins; Sulfonic Acids; Ziziphus

Four different assays (the Folin-Ciocalteu, DPPH, enzymatic method, and inhibitory activity on lipid peroxidation) based on radically different physicochemical principles and normally used to determine the antioxidant activity of food have been confronted and utilized to investigate the antioxidant activity of fruits originated from Brazil, with particular attention to more exotic and less-studied species (jurubeba, Solanum paniculatum; pequi, Caryocar brasiliense; pitaya, Hylocereus undatus; siriguela, Spondias purpurea; umbu, Spondias tuberosa) in order to (i) verify the correlations between results obtained by the different assays, with the final purpose to obtain more reliable results avoiding possible measuring-method linked mistakes and (ii) individuate the more active fruit species. As expected, the different methods give different responses, depending on the specific assay reaction. Anyhow all results indicate high antioxidant properties for siriguela and jurubeba and poor values for pitaya, umbu, and pequi. Considering that no marked difference of ascorbic acid content has been detected among the different fruits, experimental data suggest that antioxidant activities of the investigated Brazilian fruits are poorly correlated with this molecule, principally depending on their total polyphenolic content.

Topics: Antioxidants; Ascorbic Acid; Biphenyl Compounds; Brazil; Fruit; Humans; Lipid Peroxidation; Molybdenum; Oxidation-Reduction; Phenols; Picrates; Plant Extracts; Tungsten Compounds

Quinoa is a pseudocereal that is grown mainly in the Andes. It is a functional food supplement and ingredient in the preparation of highly nutritious food. In this paper we evaluate the potential of near infrared spectroscopy (NIR) for the determination of vitamin E and antioxidant capacity in the quinoa as total phenol content (TPC), radical scavenging activity by DPPH (2,2-diphenyl-2-picryl-hydrazyl) and cupric reducing antioxidant capacity (CUPRAC) expressed as gallic acid equivalent (GAE). For recording NIR a fiber optic remote reflectance probe applied directly on the quinoa samples without treatment was used. The regression method used was modified partial least squares (MPLS). The multiple correlation coefficients (RSQ) and the standard prediction error corrected (SEP(C)) were for the vitamin E (0.841 and 1.70 mg 100 g(-1)) and for the antioxidants TPC (0.947 and 0.08 mg GAE g(-1)), DPPH radical (0.952 and 0.23 mg GAE g(-1)) and CUPRAC ( 0.623 and 0.21 mg GAE g(-1)), respectively. The prediction capacity of the model developed measured by the ratio performance deviation (RPD) for vitamin E (2.51), antioxidants TPC (4.33), DPPH radical (4.55) and CUPRAC (1.55) indicated that NIRS with a fiber optic probe provides an alternative for the determination of vitamin E and antioxidant properties of the quinoa, with a lower cost, higher speed and results comparable with the chemical methods.

Topics: Antioxidants; Ascorbic Acid; Biphenyl Compounds; Calibration; Chenopodium quinoa; Copper; Gallic Acid; Least-Squares Analysis; Phenols; Picrates; Spectroscopy, Near-Infrared; Vitamin E

Fermented products, dried mycelia broth, and mycelia-free broth of Laetiporus sulphureus submerged cultures were extracted with ethanol and hot water under optimal culture conditions and investigated for their antioxidant properties. Ethanolic extracts from dried mycelia broth (EEM) and mycelia-free broth (EEB) and hot water extracts from dried mycelia (HWEM) show extraordinary antioxidant properties for all EC50 values below 10 mg/mL except for EEM, as measured by the scavenging effects on DPPH radicals and chelating effects on ferrous ions. Ascorbic acid is rich in EEB and α-tocopherol, and total flavonoids are abundant in EEM. Total phenols are mainly found in EEB and HWEM. There is a high correlation between total phenol content and EC50 values. The correlation coefficient (R2) of the reducing power is 0.994; the R2 of the scavenging effect on DPPH radicals is 0.992; the R2 of the chelating effects on ferrous ions is 0.949; and the R2 of the scavenging effect on superoxide anions is 0.995. These results suggest that extracts of L. sulphureus fermented products are of considerable application potential in antioxidant-related pharmaceutical industries.

Topics: alpha-Tocopherol; Antioxidants; Ascorbic Acid; Basidiomycota; Biological Products; Biphenyl Compounds; Fermentation; Ferrous Compounds; Flavonoids; Mycelium; Phenols; Picrates; Superoxides

The effects of short-term ultraviolet B (UV-B) irradiation on sweet basil (Ocimum basilicum L. cv. Cinnamon) plants at the 3-4 leaf pair and flowering stages were examined in controlled environment growth chambers. Plants were exposed to 0 (reference), 2 and 4 kJ UV-B m(-2) day(-1) over 7 days.. Exposure of basil plants to supplementary UV-B light resulted in increased assimilating leaf area, fresh biomass and dry biomass. Stimulation of physiological functions in young basil plants under either applied UV-B dose resulted in increased total chlorophyll content but no marked variation in carotenoid content. At the flowering stage the chlorophyll and carotenoid contents of basil were affected by supplementary UV-B radiation, decreasing with enhanced UV-B exposure. Both total antioxidant activity (2,2-diphenyl-1-picrylhydrazyl free radical assay) and total phenolic compound content were increased by UV-B light supplementation. Young and mature basil plants differed in their ascorbic acid content, which was dependent on UV-B dose and plant age. UV-B radiation resulted in decreased nitrate content in young basil plants (3-4 leaf pair stage).. These results indicate that the application of short-exposure UV-B radiation beneficially influenced both growth parameters and biochemical constituents in young and mature basil plants.

Topics: Antioxidants; Ascorbic Acid; Biomass; Biphenyl Compounds; Carotenoids; Chlorophyll; Flowers; Nitrates; Nitrogen; Ocimum basilicum; Phenols; Phytochemicals; Picrates; Plant Development; Plant Leaves; Ultraviolet Rays

Hardy kiwifruit (Actinidia arguta) is a new species, commercially grown in recent years. Total phenolics (TPC), vitamin C (TAA) content, antioxidant activity (AA) and their year-to-year variability in seven hardy kiwifruit clones were evaluated. TPC was determined using the Folin-Ciocalteu reagent assay. TAA was estimated by determination of l-ascorbic acid and l-dehydroascorbic acid levels using high-performance liquid chromatography. AA was measured using diphenyl-1-picryl-hydrazyl (DPPH), 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) and OH radicals.. The highest content of vitamin C, in all seasons, was found in D11 (1447-2181 mg kg(-1) fresh weight) and phenolics for D11 and M1 clones (2583-3312 and 2228-3414 mg gallic acid equivalents kg(-1) fresh weight, respectively). TPC and TAA content showed significant differences between hardy kiwifruit clones and showed significant year-to-year variability. Each year, the level of AA was significantly higher for D11 (DPPH, ABTS). AA was strongly correlated with TPC and TAA content in Actinidia fruit.. Hardy kiwifruit are an important source of vitamin C and phenolics, which resulted in their good antioxidant potential. A significantly higher content of these compounds was found in fruit of hybrid origin, which suggests that A. purpurea × A. arguta clones may be useful genetic resources for further interspecific hybridization.

Topics: Actinidia; Antioxidants; Ascorbic Acid; Benzothiazoles; Biphenyl Compounds; Chimera; Diet; Fruit; Humans; Hydroxyl Radical; Phenols; Picrates; Seasons; Species Specificity; Sulfonic Acids

A potent endophytic fungus, Fusarium solani SD5 was used for exopolysaccharide (EPS) production. The isolated EPS were purified and major EPS fraction (PS-I); rhamno galactan was used to evaluate anti oxidant activities in vitro. EPS (PS-I) showed significant free radical scavenging effect on DPPH (1,1-diphenyl-2-picrylhydrazyl) and scavenging potency is indicated by IC(50) value 578.541 ± 33.256 μg/ml. EPS (PS-I) significantly induced antioxidant parameters of peritoneal macrophage cells at a concentration dependent manner and at 500 μg/ml it showed maximum protective effect against free radicals [malondialdehyde (MDA) 0.178 ± 0.015; super oxide dismutase (SOD) 41.287 ± 1.051; glutathione peroxidase (GPx) 30.182 ± 1.237; reduced glutathione (GSH) 56.892 ± 1.272; oxidized glutathione (GSSG) 8.458 ± 0.768]. MTT [3-(4,5-dimethylthiazol-2-yl)-2,5 diphenyltetrazolium bromide] cytotoxicity assay indicated that EPS (PS-I) had no significant cytotoxic effect (concentration up to 500 μg/ml) on macrophage cells. Present findings suggested that the EPS (PS-I) may become a potential nontoxic exogenous antioxidant.

Topics: Animals; Ascorbic Acid; Biphenyl Compounds; Cell Survival; Cells, Cultured; Endophytes; Free Radical Scavengers; Free Radicals; Fungal Polysaccharides; Fusarium; Glutathione; Glutathione Peroxidase; Lipid Peroxidation; Macrophages, Peritoneal; Male; Malondialdehyde; Mice; Picrates; Superoxide Dismutase; Tetrazolium Salts; Thiazoles

Malpighia glabra L, popularly known as acerola, is considered a functional fruit and therefore is taken to prevent disease or as adjuvant to treatment strategies, since the fruit is an undeniable source of vitamin C, carotenoids, and flavonoids. Acerola is a natural source of vitamin C, flavonoids, and carotenoids. Its chemical composition is affected by genetic uniformity of the orchards and environmental factors. Considering the extensive growth of the culture of acerola in Brazil as well as its widespread use, this study evaluates the genotoxic and antigenotoxic activity of acerola in relation to geographical origin using the comet assay in mice blood cells in vitro. No acerola samples showed potential to induce DNA damage, independently of origin. Also, for antigenotoxicity activity, only the acerola sample from São Paulo reduced DNA damage induced by hydrogen peroxide (by about 56%). The sample from Ceará showed good antioxidant activity by the 2,2-diphenyl-1-picrylhydrazyl assay, in agreement with its higher rutin, quercetin, and vitamin C levels. Additional studies with other treatment regimens are necessary to better understand the impact of the complex mixture of acerola on genomic stability.

Topics: Animals; Ascorbic Acid; Biphenyl Compounds; Brazil; Chromatography, High Pressure Liquid; Comet Assay; DNA Damage; Free Radical Scavengers; Free Radicals; Fruit; Geography; Inhibitory Concentration 50; Male; Malpighiaceae; Mice; Picrates; Plant Extracts; Quercetin; Rutin

A neutral exopolysaccharide (EPS), designated LPC-1, was isolated from the culture of Lactobacillus plantarum C88 and purified by ion-exchange and gel-permeation chromatography. LPC-1 had an average molecular weight of 1.15 × 10(6) Da, and it was composed of galactose and glucose with a molar ratio of 1:2. The antioxidant activity of LPC-1 was evaluated with the in vitro scavenging abilities on hydroxyl and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals. The results indicated that LPC-1 had good scavenging ability on hydroxyl radicals. Furthermore, the protective effect of LPC-1 on H(2)O(2)-induced Caco-2 cells oxidative injury was investigated. As results, LPC-1 inhibited the formation of malondialdehyde (MDA) and raised the activities of superoxide dismutase (SOD) and total antioxidant capacities (T-AOC) in a dose-dependent manner. These results demonstrate that the EPS from L. plantarum C88 has antioxidant effects that may involve scavenging of reactive oxygen species (ROS), up-regulation of enzymatic and non-enzymatic antioxidant activities, and reduction of lipid peroxidation.

Topics: Antioxidants; Ascorbic Acid; Biphenyl Compounds; Caco-2 Cells; Chromatography, Ion Exchange; Free Radical Scavengers; Humans; Hydrogen Peroxide; Kinetics; Lactobacillus plantarum; Malondialdehyde; Picrates; Polysaccharides; Reference Standards; Superoxide Dismutase

The catechin (-)-epigallocatechin-3-gallate (EGCG) exhibits high antioxidant activity and it has been reported to provide protection of the skin against damage induced by solar UV radiation. However, EGCG is highly unstable under sunlight. The present study aimed to compare the effectiveness of the co-antioxidant agents vitamin E, butylated hydroxytoluene, vitamin C and a-lipoic acid for their potential to protect the catechin from photochemical degradation. Model creams (oil-in-water emulsions) containing EGCG (1%, w/w) alone or combined with equimolar concentrations of co-antioxidant were exposed to a solar simulator at an irradiance corresponding to natural sunlight. Photodegradation was evaluated by HPLC-UV and HPLC-ESI-MS/MS. Addition of the co-antioxidants vitamin C and a-lipoic acid to the formulation significantly reduced the light-induced decomposition of EGCG from 76.9 ± 4.6% to 20.4 ± 2.7% and 12.6 ± 1.6%, respectively. Conversely, butylated hydroxytoluene had no effect (EGCG loss, 78.1 ± 4.6%) and vitamin E enhanced the EGCG photolysis to 84.5 ± 3.4%. The functional stability of the catechin in the creams exposed to the solar simulator was also evaluated by measuring the in vitro antioxidant activity. Following irradiation, the reduction of the EGCG formulation antioxidant power was lower (21.8%) than the extent of degradation (76.9%), suggesting the formation of photoproducts with antioxidant properties. The influence of the examined co-antioxidants on the functional stability of the catechin under simulated sunlight paralleled that measured for the EGCG photodecomposition, a-lipoic acid exerting the greatest stabilising effect (antioxidant activity decrease, 1.4%). These results demonstrated that a-lipoic acid is an effective co-antioxidant agent for the stabilization of EGCG in dermatological products for skin photoprotection.

Topics: Antioxidants; Ascorbic Acid; Biphenyl Compounds; Butylated Hydroxytoluene; Catechin; Chemistry, Pharmaceutical; Chromatography, High Pressure Liquid; Drug Stability; Emulsions; Free Radicals; Light; Oxidation-Reduction; Photolysis; Picrates; Skin Cream; Spectrometry, Mass, Electrospray Ionization; Tandem Mass Spectrometry; Thioctic Acid; Vitamin E

Two novel phlorotannins with a molecular weight of 974, temporarily named 974-A and 974-B, were isolated from the polyphenol powder prepared from the edible marine brown alga Ecklonia kurome Okamura, and their chemical structures were determined by spectroscopic method. The isolated yield of the total of 974-A and 974-B was approximately 4% (w/w) from the polyphenol powder. In 974-A, the carbon at the C2' position in the A ring of phlorofucofuroeckol-A forms a C-C bond with the carbon at the C2″ position of the C ring of triphloretol-B, while in 974-B, phlorofucofuroeckol-B and triphloretol-B form a C-C bond in the same manner as in 974-A. These structures were supported by high resolution-MS/MS data. To evaluate the antioxidant activities, the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging assay and intracellular radical scavenging assay, using 2',7'-dichlorofluorescin diacetate (DCFH-DA), were performed for 974-A, 974-B, and four known phlorotannins. The results of the DPPH assay showed that the IC(50) values of 974-A, 974-B, phlorofucofuroeckol-A, and dieckol were significantly smaller than those of phlorofucofuroeckol-B, phloroglucinol, α-tocopherol, and ascorbic acid. Furthermore, the DCFH-DA assay suggested that 974-A, 974-B, and dieckol reduce intracellular reactive oxygen species most strongly among the tested compounds.

Topics: alpha-Tocopherol; Animals; Antioxidants; Ascorbic Acid; Benzofurans; Biphenyl Compounds; Cell Line; Cell Line, Tumor; Dioxins; Fluoresceins; Free Radical Scavengers; Humans; Mass Spectrometry; Mice; Phaeophyceae; Phloroglucinol; Picrates; Polyphenols; Tannins

The current study targets the chemical constituents of Caesalpinia decapetala (Roth) Alston and investigates the bioactivities of the isolated compounds. Fourteen known compounds were isolated using column chromatography, and structural identification was performed by physical and spectral analyses. The biological activities of the compounds were also evaluated by 3-(4,5-dimethythiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) and 2,2-diphenlyl-1-picrylhydrazyl (DPPH) assays. Emodin (6), baicalein (9), and apigenin (12) displayed antitumor activities against the MGC-803 cell line, while quercetin (2), rutin (5), baicalein (9), and epicatechin (13) showed stronger DPPH scavenging activities compared with ascorbic acid. Andrographolide (1), quercetin (2), bergenin (4), rutin (5), emodin (6), betulin (7), baicalein (9), polydatin (10), salicin (11), and apigenin (12), were obtained from C. decapetala (Roth) Alston for the first time.

Topics: Antineoplastic Agents; Antineoplastic Agents, Phytogenic; Ascorbic Acid; Benzopyrans; Benzyl Alcohols; Biphenyl Compounds; Caesalpinia; Cell Line, Tumor; Cell Survival; Emodin; Flavonoids; Free Radical Scavengers; Free Radicals; Glucosides; Humans; Inhibitory Concentration 50; Molecular Structure; Picrates; Plant Extracts; Stilbenes; Triterpenes

This study was designed to investigate the potentially protective effects of glycyrrhetinic acid (GA) and the role of transcription factor nuclear factor-erythroid 2(NF-E2)-related factor 2 (Nrf2) signaling in the regulation of Carbon Tetrachloride (CCl(4))-induced chronic liver fibrosis in mice. The potentially protective effects of GA on CCl(4)-induced chronic liver fibrosis in mice were depicted histologically and biochemically. Firstly, histopathological changes including regenerative nodules, inflammatory cell infiltration and fibrosis were induced by CCl(4).Then, CCl(4) administration caused a marked increase in the levels of serum aminotransferases (GOT, GPT), serum monoamine oxidase (MAO) and lipid peroxidation (MDA) as well as MAO in the mice liver homogenates. Also, decreased nuclear Nrf2 expression, mRNA levels of its target genes such as superoxide dismutase 3 (SOD3), catalase (CAT), glutathione peroxidase 2 (GPX2), and activity of cellular antioxidant enzymes were found after CCl(4) exposure. All of these phenotypes were markedly reversed by the treatment of the mice with GA. In addition, GA exhibited the antioxidant effects in vitro by on FeCl(2)-ascorbate induced lipid peroxidation in mouse liver homogenates, and on DPPH scavenging activity. Taken together, these results suggested that GA can protect the liver from oxidative stress in mice, presumably through activating the nuclear translocation of Nrf2, enhancing the expression of its target genes and increasing the activity of the antioxidant enzymes. Therefore, GA may be an effective hepatoprotective agent and viable candidate for treating liver fibrosis and other oxidative stress-related diseases.

Topics: Animals; Antioxidants; Ascorbic Acid; Biphenyl Compounds; Chronic Disease; Cytoprotection; Ferrous Compounds; Fluorocarbons; Glycyrrhetinic Acid; Lipid Peroxidation; Liver; Liver Cirrhosis; Male; Mice; NF-E2-Related Factor 2; Oxidative Stress; Picrates; RNA, Messenger; Up-Regulation

Twelve Colorado-grown specialty potato clones were evaluated for total phenolic content, antioxidant activity and ascorbic acid content at harvest and after 2, 4, 6 and 7 months cold storage at 4 °C. Potato clones were categorized as pigmented ('CO97226-2R/R', 'CO99364-3R/R', 'CO97215-2P/P', 'CO97216-3P/P', 'CO97227-2P/P', 'CO97222-1R/R', 'Purple Majesty', 'Mountain Rose' and 'All Blue'), yellow ('Yukon Gold') and white fleshed ('Russet Nugget', 'Russet Burbank'). Folin-Ciocalteu reagent was used to estimate total phenolic content, and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS(•+) ) and 2,2-diphenyl-1-picrylhydrazyl (DPPH(•) ) radical scavenging assays were used to estimate antioxidant capacity.. Pigmented potato genotypes had significantly higher total phenolic content and antioxidant activity at all data points than yellow- and white-fleshed cultivars. Vitamin C content was higher in 'Yukon Gold' than in the other clones. The highest level of vitamin C in all clones was at harvest and after 2 months in cold storage. Vitamin C content in all potato clones dropped rapidly with longer intervals of cold storage. Although total phenolic content and antioxidant activity fluctuated during cold storage, after 7 months of cold storage their levels were slightly higher than at harvest. Total phenolic content was better correlated with Trolox equivalent antioxidant capacity (TEAC)/ABTS(•+) than the TEAC/DPPH(•) radical scavenging assay.. Pigmented potato clones had significantly higher total phenolic content and antioxidant activity, while the yellow-fleshed potato cultivar 'Yukon Gold' had significantly higher vitamin C content. Vitamin C content decreased in all potato clones during cold storage, while total phenolics increased in pigmented clones.

Topics: Antioxidants; Ascorbic Acid; Benzothiazoles; Biphenyl Compounds; Cold Temperature; Diet; Food Storage; Humans; Phenols; Picrates; Pigments, Biological; Plant Tubers; Solanum tuberosum; Species Specificity; Sulfonic Acids

Two new series of compounds namely, 3,6-disubstituted-1,2,4-triazolo[3,4-b][1,3,4]thiadizoles (5a-j) and 5,6-dihydro-3,6-disubstituted-1,2,4-triazolo[3,4-b][1,3,4]thiadizoles (7a-j) were prepared. In continuation of a previously reported study, the first series (5a-j) were synthesized by the cyclocondensation of 4-amino-5-(2-bromo-5-methoxyphenyl)-2,4-dihydro-3H-1,2,4-triazole-3-thione (4) with various substituted aromatic carboxylic acids in phosphorus oxychloride and the second series (7a-j) by the reaction of (4) with various substituted aromatic aldehydes in the presence of p-Toluene sulfonic acid. Reaction of (4) with the aldehyde (9) afforded the Schiff's base (10) and not the cyclised product (11) on treatment with p-Toluene sulfonic acid. Synthesized compounds were structurally confirmed by spectral analysis and studied for their anti-inflammatory, analgesic, anti-oxidant and antimicrobial activities. Some of the tested compounds showed significant pharmacological activities.

Topics: Analgesics; Animals; Anti-Bacterial Agents; Anti-Inflammatory Agents; Antifungal Agents; Biphenyl Compounds; Chemistry Techniques, Synthetic; Free Radical Scavengers; Picrates; Rats; Thiadiazoles; Triazoles

Twenty five Imine resveratrol analogues (IRAs) were synthesized, replacing the C=C bond in resveratrol with CN bond, as well as substitution modifications on aromatic rings. Radical scavenging activities against DPPH, along with singlet oxygen quenching capacities were evaluated, and further confirmed using density functional theory calculations (DFT). It was found that IRAs bearing ortho-OH on B ring have better radical scavenging activities against DPPH than resveratrol, these compounds were also found to be effective (1)O(2) quenchers. Theoretical studies on the reaction mechanism of these compounds with (1)O(2) suggest that the 1,3-addition to a double bond with a -OH group with the formation of allylic hydroperoxide is the most probable reaction route.

Topics: Antioxidants; Biphenyl Compounds; Electron Spin Resonance Spectroscopy; Imines; Picrates; Resveratrol; Singlet Oxygen; Stilbenes; Structure-Activity Relationship

A novel series of 3-(substituted)-aryl-5-(9-methyl-3-carbazole)-1H-2-pyrazolines (5a-o) has been synthesized and the structures of newly synthesized compounds were characterized by IR, (1)H NMR and mass spectral analysis. All the synthesized compounds were evaluated for their in vitro and in vivo anti-inflammatory activity, and also for their antioxidant activity. Compounds 5b, 5c, 5d and 5n were found to be selective COX-2 inhibitors. Compound 5c was found to potent inhibitor of the carrageenin induced paw edema in rats. Most of the compounds exhibited good DPPH and superoxide radical scavenging activity, while compounds 5c, 5d, 5i and 5k exhibited good hydroxyl radical scavenging activity. Molecular docking result, along with the biological assay data, suggested that compound 5c was a potential anti-inflammatory agent.

Topics: Animals; Anti-Inflammatory Agents, Non-Steroidal; Antioxidants; Biphenyl Compounds; Cyclooxygenase 1; Cyclooxygenase 2; Cyclooxygenase 2 Inhibitors; Dose-Response Relationship, Drug; Edema; Free Radical Scavengers; Models, Molecular; Molecular Structure; Picrates; Pyrazoles; Rats; Stereoisomerism; Structure-Activity Relationship; Superoxides

The biological importance of antioxidants influenced to synthesize some curcumin-related compounds as potential antioxidants. Accordingly, a series of 2,4-diaryl-3-azabicyco[3.3.1]nonan-9-ones were synthesized with polyphenolic and/or polymethoxyphenyl groups by modified Mannich condensations. The yield was significantly improved using BF(3)·SiO(2) as heterogeneous catalyst under mild conditions. Stereochemistry of all the synthesized compounds was established as twin-chair with an equatorial disposition of the aryl groups, through their NMR and XRD interpretations. The ABNs 8 (curcumin analog) and 10 (bis-demethoxycurcumin analog) showed an effective profile over curcumin, α-tocopherol, and vitamin C by chemical methods. Further, the efficiency of one of the active molecules, ABN 10, was demonstrated by its intracellular ROS inhibition activity on RAW 264.7 macrophage cells by FACS analysis in dose-dependent manner.

Topics: alpha-Tocopherol; Animals; Antioxidants; Ascorbic Acid; Biphenyl Compounds; Boranes; Catalysis; Cell Line; Curcumin; Macrophages; Mannich Bases; Mice; Models, Molecular; Oxidation-Reduction; Picrates; Reactive Oxygen Species; Silicon Dioxide

An uncommon 2,5-diarylcyclopentenone compound, preussidone (1), and a new biphenyl compound, 1',5-dimethoxy-3,5'-dimethyl-2,3'-oxybiphenyl-1,2'-diol (4), together with two known biphenyl compounds, 5-methoxy-3,5'-dimethyl-2,3'-oxybiphenyl-1,1',2'-triol (2) and cyperin (3), were obtained from a Preussia typharum isolate that was procured using a panel of unconventional media formulations. The structures of the new compounds were established by NMR and mass spectrometry, while the absolute configuration of 1 was assigned by quantum chemical ECD and VCD calculations. The antimicrobial and DPPH radical scavenging activities of 1-4 were tested. Compounds 2 and 4 exhibited DPPH radical scavenging activities that were comparable to the positive control ascorbic acid.

Topics: Ascomycota; Biphenyl Compounds; Cyclopentanes; Free Radical Scavengers; Molecular Structure; Nuclear Magnetic Resonance, Biomolecular; Picrates

This study represents the synthesis of a new series of N-substituted phenyl-5-methyl-6-(5-(4-substituted phenyl)-1,3,4-oxadiazol-2-yl)thieno[2,3-d]pyrimidin-4-amine derivatives (4a-l) and substituted phenylamino-5-methylthieno[2,3-d]pyrimidine-6-carboxylic acid derivatives (3a-d). The newly synthesized compounds were characterized by (1)H NMR, (13)C NMR, LC-MS and IR analyses. All these novel compounds were screened for their in vitro antioxidant activity by employing DPPH, hydrogen peroxide, and nitric oxide radical scavenging assays. Compounds 4k, 4j, 4d, and 4e showed significant radical scavenging due to the presence of electron donating substituent on both sides of the thienopyrimidine ring enhances the activity and electron withdrawing groups like nitro decrease.

Topics: Antioxidants; Biphenyl Compounds; Free Radical Scavengers; Hydrogen Peroxide; Nitric Oxide; Oxadiazoles; Picrates; Pyrimidines

To evaluate the phytochemical constituents and antioxidant activities of aqueous extract of Schotia latifolia (S. latifolia) bark locally used for the treatment of oxidative stress-induced ailments in South Africa.. The antioxidant and free radical scavenging activity of aqueous extract of the plant was assessed against 1,1-diphenyl-2-picrylhydrazyl (DPPH), nitric oxide (NO), 2,2'-azinobis (3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS) and the ferric reducing agent. Total phenolics, flavonoids, flavonols and proanthocyanidins were also determined to assess their corresponding effect on the antioxidant activity of this plant.. The activities of plant extract against DPPH, ABTS and NO radicals were concentration dependent with IC50 value of 0.06, 0.05 and 0.05 mg/mL, respectively. The reducing power of the extract was greater than that of butylated hydroxyl toluene (BHT) and ascorbic acid which were used as standard drugs in a concentration dependent manner. The total phenolics content of the aqueous bark extract was (193.33±0.03 TE/g), followed by flavonoids (72.70±0.01 QE/g), proanthocyanidins (48.76±0.00 CE/g) and flavonols (47.76±0.21 QE/g). Phytochemical analysis revealed the presence of percentage tannin (11.40±0.02), alkaloid (9.80±0.01), steroids (18.20±0.01), glycosides (29.80±0.01) and saponins (6.80±0.00). The results exhibited a positive linear correlation between these polyphenols and the free radical scavenging activities.. Our findings provide evidence that the crude aqueous extract of S. latifolia is a potential source of natural antioxidants and this justifies its uses in folkloric medicines.

Topics: Antioxidants; Ascorbic Acid; Biphenyl Compounds; Butylated Hydroxytoluene; Fabaceae; Flavonoids; Flavonols; Free Radical Scavengers; Medicine, African Traditional; Nitric Oxide; Oxidative Stress; Phytochemicals; Picrates; Plant Bark; Plant Extracts; Proanthocyanidins; South Africa; Sulfonic Acids; Thiazoles

Waste obtained from six genotypes of tomato was subjected to evaluation as potential sources of hydrophilic antioxidants on the basis of content of total phenolics (TPh; from 11.7 to 18.6 mg/g), total flavonoids (TFl; from 7.62 to 12.1 mg/g) and ascorbic acid (AA; from 0.51 to 1.89 mg/g), and antioxidant activities. The antioxidant activities of tomato waste extracts were evaluated using 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity, ferrous ion chelating activity (CA) and reducing power (RP) assay. The O(2) tomato waste extract was found to have the strongest antioxidant activity in scavenging DPPH radicals (effective concentration, EC(50) = 0.18 mg/ml). The Saint Pierre tomato waste extract showed the best performance in RP assay (EC(50) = 1.57 mg/ml). The Rutgers tomato waste extract exhibited a strongest CA (EC(50) = 1.49 mg/ml). The linear correlation analysis produced moderate-to-high correlation coefficients between the antioxidant activities and TPh, TFl and AA.

Topics: Antioxidants; Ascorbic Acid; Biphenyl Compounds; Chelating Agents; Food Industry; Genotype; Humans; Hydrophobic and Hydrophilic Interactions; Picrates; Plant Extracts; Polyphenols; Solanum lycopersicum; Waste Products

The chemical compositions of the stem and leaf sheath of few-flower wild rice were analysed. In addition, their extracts were evaluated for diphenylpicrylhydrazyl (DPPH) free radical-scavenging activity, ferric-reducing antioxidant power and angiotensin-converting enzyme (ACE)-inhibitory activity, since these are important properties of sources of nutraceuticals or functional foods.. The stems contained more ascorbic acid (0.06 g kg(-1) fresh weight), protein (28.18 g kg(-1) dry weight (DW)), reducing sugars (308.54 g kg(-1) DW), water-soluble pectin (20.63 g kg(-1) DW), Na(2) CO(3) -soluble pectin (44.14 g kg(-1) DW), K (8 g kg(-1) dry matter (DM), S (6 g kg(-1) DM) and P (5 g kg(-1) DM) but less starch, total dietary fibre, Si, Na and Ca than the leaf sheaths. The DPPH free radical-scavenging IC(50) values of the stem and leaf sheath extracts were 19.28 and 21.22 mg mL(-1) respectively. In addition, the ACE-inhibitory IC(50) value of the stem extracts was 38.54 mg mL(-1).. Both the stem and leaf sheath extracts exhibited good antioxidant properties, while good ACE-inhibitory activity was detected only in the phosphate buffer solution extracts of the stem. Few-flower wild rice could be processed into formula feeds for fish, poultry, etc. or functional foods for persons with high blood pressure.

Topics: Angiotensin-Converting Enzyme Inhibitors; Antioxidants; Ascorbic Acid; Biphenyl Compounds; Dietary Fiber; Dietary Proteins; Dietary Sucrose; Dietary Supplements; Ferric Compounds; Flowers; Functional Food; Humans; Oryza; Pectins; Picrates; Plant Extracts; Plant Leaves; Plant Proteins; Plant Stems; Poaceae; Starch; Trace Elements

The occurrence of three known benzophenones, namely annulatophenonoside, acetylannulatophenonoside and annulatophenone as well as a flavonol O-glycoside guajaverin in the aerial parts of Hypericum maculatum Crantz was established. In addition, hyperoside, isoquercitrin and miquelianin were isolated from this plant, as well. Radical scavenging and antioxidant activities of the isolated compounds were examined using 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) diammonium salt (ABTS) free radicals, ferric reducing antioxidant power (FRAP) assay and inhibition of lipid peroxidation in linoleic acid system by the ferric thiocyanate method. Isoquercitrin demonstrates the highest DPPH radical scavenging (96.6 ± 0.3%), FRAP (23.8 ± 0.2 Trolox equivalent, TE mol⁻¹) and antioxidant activity in linoleic acid system. Guajaverin and acetylannulatophenonoside show significantly strong ABTS radical scavenging activity (93.9 ± 0.4% and 93.4 ± 0.6%, respectively), which is comparable to that of ascorbic acid (96.2 ± 0.4%).

Topics: Antioxidants; Ascorbic Acid; Benzophenones; Benzothiazoles; Biphenyl Compounds; Flavonoids; Hypericum; Picrates; Sulfonic Acids

The commercial development of plants as sources of antioxidants that can be used to enhance the properties of foods, for nutritional purposes and preservation as well as for prevention of oxidation-related diseases, is currently of major interest. Rosehip (Rosa canina L.) is a rich source of vitamin C and polyphenols.. Phytochemicals in rosehip tea were separated into three fractions: Fr1 (vitamin C, 39.17 mg kg(-1)), Fr2 (flavonoids, 451.05 µg kg(-1)) and Fr3 (phenolic acids, 504.69 µg kg(-1)). Quercetin and ellagic acid were the most abundant polyphenolic compounds. Rosehip fractions, primarily rosehip flavonoids (EC(50) = 49 mg L(-1)), showed high antioxidant activity towards 2,2-diphenyl-1-picrylhydrazyl radicals (DPPH(•)). Cell growth effects of rosehip fractions were assessed in HeLa, MCF7 and HT-29 cell lines, with the lowest IC(50) values being determined for rosehip flavonoids, (80.63, 248.03 and 363.95 mg L(-1) respectively). However, the vitamin C fraction did not inhibit the growth of tested tumour cells.. The results of this study confirm that vitamin C and flavonoids are responsible for the antioxidant activity of rosehip tea, while only polyphenols contribute to its antiproliferative activity.

Topics: Antineoplastic Agents, Phytogenic; Antioxidants; Ascorbic Acid; Biphenyl Compounds; Cell Line, Tumor; Ellagic Acid; Flavonoids; Free Radicals; Fruit; HeLa Cells; Humans; Inhibitory Concentration 50; Neoplasms; Phytotherapy; Picrates; Plant Extracts; Polyphenols; Quercetin; Rosa

Baccharis trimera is a plant popularly used as a tea and to treat gastrointestinal diseases and inflammatory processes as well. The total phenolic content was determined and the antioxidant and anti-inflammatory activities of six extracts (dichloromethane, ethyl acetate, butanol, aqueous, saponin and phenolic) from B. trimera were evaluated. Using carrageenan-induced pleurisy as a model of acute inflammation, the phenolic extract at 15 mg/kg decreased significantly the analyzed parameters when compared to the carrageenan group ( p < 0.05), thus showing potential anti-inflammatory activity. The total phenolic content and antioxidant activity were evaluated by the Folin-Ciocalteau and DPPH methods, respectively. Phenolic and ethyl acetate extracts presented higher antioxidant activity ( p < 0.05) than ascorbic acid. The phenolic extract also showed the highest antioxidant potential in relation to the other extracts, thus suggesting that the antioxidant and anti-inflammatory activities were due to the presence of phenolic compounds.

Topics: Animals; Anti-Inflammatory Agents; Antioxidants; Ascorbic Acid; Baccharis; Biphenyl Compounds; Carrageenan; Female; Inhibitory Concentration 50; Nitric Oxide; Phenols; Picrates; Plant Extracts; Plant Leaves; Pleurisy; Rats; Rats, Wistar

The present investigation was carried out to appraise the levels of total phenols and vitamin C as well as antioxidant potential at three different ripening stages (un-ripe, semi-ripe and fully-ripe) of guava (Psidium guajava L.) fruit collected from three different geographical regions of Pakistan (Islamabad, Faisalabad and Bhakkar). The antioxidant potential of guava fruit extracts was assessed by means of different in-vitro antioxidant assays, namely inhibition of peroxidation in linoleic acid system, reducing power and radical scavenging capability. Overall, fruit at the un-ripe stage (G1) exhibited the highest levels of TPC, TFC, reducing power and DPPH radical scavenging activity, followed by the semi-ripe (G2) and fully-ripe (G3) stages. On the other hand, vitamin C content increased as the fruit maturity progressed, with highest value seen at the fully-ripe stage (G3) followed by the semi-ripe (G2) and un-ripe stage (G1). The concentration of vitamin C in fruits varied as: Faisalabad (136.4-247.9 mg 100 g⁻¹), Islamabad (89.7-149.7 mg 100 g⁻¹) and Bhakkar (73.1-129.5 mg 100 g⁻¹). The results showed that different stages of maturation and geographical locations had profound effects on the antioxidant activity and vitamin C contents of guava fruit.

Topics: Ascorbic Acid; Biphenyl Compounds; Flavonoids; Free Radical Scavengers; Fruit; Linoleic Acid; Lipid Peroxidation; Pakistan; Phenols; Picrates; Plant Extracts; Psidium; Reducing Agents

Melissa officinalis (lemon balm) infusions are used worldwide for digestive, analgesic and other pharmaceutical applications. Herein, the nutraceuticals production and antioxidant potential in garden cultivated, in vitro cultured and two commercial samples (bags and granulated) of lemon balm was compared. The profile of in vitro cultured lemon balm is closer of garden cultivated sample than of both commercial samples (bag or granulate). It presented the highest levels of proteins and ash, and the lowest energetic value. The most favorable n6/n3 ration, as also the highest PUFA (mostly α-linolenic acid), tocopherols (including α-, γ- and δ-isoforms) and ascorbic acid contents were also observed in this sample. Nevertheless, it was the commercial bag lemon balm that gave the highest antioxidant activity and the highest levels of phenolics and flavonoids. As far as we kwon, this is the first comparison of nutraceuticals and antioxidant potential of cultivated, in vitro cultured and commercial lemon balm samples. Moreover, it proved that in vitro culture might be used to stimulate vitamins production.

Topics: Antioxidants; Ascorbic Acid; beta Carotene; Biphenyl Compounds; Carbohydrates; Carotenoids; Cells, Cultured; Dietary Supplements; Fatty Acids; Free Radical Scavengers; Freeze Drying; Indicators and Reagents; Lipid Peroxidation; Melissa; Nutritive Value; Picrates; Reducing Agents; Reference Standards; Thiobarbituric Acid Reactive Substances; Tocopherols

In this study, leaves of three indigenous varieties of Mulberry namely, Morus alba L., Morus nigra L. and Morus rubra L. were investigated for their antioxidant potential and their proximate composition was determined. The yields of 80% methanolic extracts ranged between 8.28-13.89%. The contents of total phenolics (TPC), total flavonoids (TFC) and ascorbic acid (AA) ranged between 16.21-24.37 mg gallic acid equivalent (GAE)/g, 26.41-31.28 mg rutin equivalent (RE)/g and 0.97-1.49 mg/g, respectively. The antioxidant activity of leaf extracts was evaluated by measuring 1,1-diphenyl-2-picrylhydrazyl (DPPH(•)) radical scavenging actity, 2,2'-azino-bis-(3-ethylbenzthiazoline-6-sulphonic acid (ABTS(•+)) radical cation scavenging capacity and ferric ion reducing power and values ranged between 1.89-2.12, 6.12-9.89 and 0.56-0.97 mM Trolox equivalent/g of dried leaves, respectively. The investigated features reveal good nutritive and antioxidant attributes of all the varieties with mutually significant differences.

Topics: Antioxidants; Ascorbic Acid; Benzothiazoles; Biphenyl Compounds; Cations; Flavonoids; Free Radical Scavengers; Free Radicals; Lipids; Methanol; Morus; Phenol; Phenols; Picrates; Plant Extracts; Plant Leaves; Rutin; Species Specificity; Sulfonic Acids

A new resveratrol dimer, acuminatol (1), was isolated along with five known compounds from the acetone extract of the stem bark of Shorea acuminata. Their structures and stereochemistry were determined by spectroscopic methods, which included the extensive use of 2D NMR techniques. All isolated compounds were evaluated for their antioxidant activity using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity (RSA) and the β-carotene-linoleic acid (BCLA) assays, and compared with those of the standards of ascorbic acid (AscA) and butylated hydroxytoluene (BHT). All compounds tested exhibited good to moderate antioxidant activity in the DPPH assay (IC₅₀s 0.84 to 10.06 mM) and displayed strong inhibition of β-carotene oxidation (IC₅₀s 0.10 to 0.22 mM). The isolated compounds were evaluated on the Vero cell line and were found to be non-cytotoxic with LC₅₀ values between 161 to 830 µM.

Topics: Animals; Ascorbic Acid; beta Carotene; Biphenyl Compounds; Butylated Hydroxytoluene; Chlorocebus aethiops; Dipterocarpaceae; Free Radical Scavengers; Free Radicals; Heterocyclic Compounds, 4 or More Rings; Inhibitory Concentration 50; Molecular Conformation; Molecular Structure; Oxidation-Reduction; Picrates; Plant Bark; Plant Extracts; Reference Standards; Stereoisomerism; Vero Cells

Defatted rice bran extracts were obtained by subcritical treatment using aqueous acetone as extractant. Treatment with 40% (v/v) acetone at 230 °C for 5 min yielded an extract with the highest 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity (0.274 mmol of ascorbic acid/g of bran), total carbohydrate (0.188 g/g of bran), protein (0.512 g/g of bran), and total phenolic contents (88.2 mg of gallic acid/g of bran). The effect of treatment temperature (70-230 °C) was investigated using 40% (v/v) acetone, and the extract under 230 °C treatment showed the highest levels of all the determinations described above. The extracts obtained with various concentrations of aqueous acetone were subjected to UV absorption spectra and HPLC analysis, and the results showed changes in composition and polarity. Antioxidative activity evaluated against oxidation of bulk linoleic acid of the extract obtained with 80% (v/v) acetone was higher than that not only of the extract from subcritical water treatment but also of that obtained 40% (v/v) acetone treatment.

Topics: Acetone; Ascorbic Acid; Biphenyl Compounds; Chromatography, High Pressure Liquid; Fatty Acids; Free Radical Scavengers; Gallic Acid; Hot Temperature; Linoleic Acid; Liquid-Liquid Extraction; Oryza; Picrates; Plant Extracts; Solvents; Water

In the present study, antioxidant properties of flavonoids and polysaccharides from tobacco (Nicotiana tabacum L.) leaves were evaluated in several in vitro systems, e.g., scavenging activities on hydroxyl, superoxide anion, 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulphonic acid) (ABTS) radicals, and reducing power. Flavonoids showed much better activity than polysaccharides in scavenging activities on free radicals. When compared to the positive control, ascorbic acid, both showed weaker antioxidant potential. However, flavonoids possessed comparable superoxide anion, DPPH and ABTS radical scavenging abilities to ascorbic acid at high concentration (600 μg/mL). Meanwhile, it was found that flavonoids had prominent effects on the reducing power, which was equivalent to ascorbic acid, and was significantly higher than polysaccharides. These results clearly indicate that flavonoids are effective in scavenging free radicals and have the potential to be powerful antioxidants. Thus, tobacco leaves could be considered as a potential source of natural antioxidants for food, pharmaceutical, cosmetics or nutraceutical industries.

Topics: Antioxidants; Ascorbic Acid; Benzothiazoles; Biphenyl Compounds; Flavonoids; Free Radical Scavengers; Free Radicals; Hydroxyl Radical; Nicotiana; Oxidation-Reduction; Picrates; Plant Extracts; Plant Leaves; Polysaccharides; Sulfonic Acids; Superoxides

There is no available information on physicochemical and antioxidant properties on Bangladeshi honey. We investigated five different monofloral and three different multifloral honey samples collected from different parts of Bangladesh.. The levels of phenolics, flavonoids, ascorbic acid, ascorbic acid equivalent antioxidant content (AEAC), proline, protein and antioxidants were determined in the honey samples using ferric reducing antioxidant power (FRAP) and 1,1-diphenyl-2-picrylhydrazyl (DPPH) assays.. The highest level of phenolic was 688.5 ± 5.9 mg Gallic acid/kg, and the highest level of flavonoid was 155 ± 6.9 mg Catechin/kg. The highest color intensity was 2034.00 ± 17.5 mAU, and the highest protein content was 8.6 ± 0.0mg/g. High levels of proline (2932.8 ± 3.7 mg/kg), ascorbic acid (154.3 ± 0.3 mg/kg), AEAC (34.1 ± 1.4mg/100 g) and FRAP (772.4 ± 2.5 μmol Fe (II)/100 g) were detected in some of the samples, especially the multifloral honey samples, indicating good antioxidant properties. A strong positive correlation was found between phenolics, flavonoids, DPPH, FRAP and color intensity, indicating that in addition to total phenolic and flavonoid concentrations, color intensity and amino acid are good indicators of the antioxidant potential of honey. Except for a single sample (BDH-6), the honey samples stored for 1.5 years at room temperature still had 5-hydroxymethylfurfural (HMF) values within the recommended range (mean = 10.93 mg/kg), indicating that the rate of HMF production in Bangladeshi honey samples is low.. It is postulated that the low rate of HMF formation could be attributed to the acidic and low moisture content in the samples. In general, multifloral honeys have higher antioxidant properties based on their high levels of phenolics, flavonoids, AEAC, DPPH and FRAP when compared to monofloral honeys. We also found that monofloral honey samples from Guizotia abyssinica and Nigella sativa had high antioxidant properties.

Topics: Antioxidants; Ascorbic Acid; Bangladesh; Biphenyl Compounds; Color; Dietary Proteins; Flavonoids; Flowers; Food Storage; Honey; Nigella sativa; Phenols; Picrates; Proline

Five known isocoumarins, monocerin (1), derivative 2, and fusarentin derivatives 3-5, and a new phthalide (6) were isolated from the endophytic fungus Colletotrichum sp. 2 selectively exhibited cytotoxic activity toward the HepG2 cell line. Compounds 2 and 4 scavenged 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radicals (IC(50) values of 23.4 and 16.4 μM, respectively) and inhibited superoxide anion radical formation (IC(50) values of 52.6 and 4.3 μM, respectively). The C-7 hydroxyl group in 2 and 4 might be important for radical scavenging activities. Isocoumarins 1-3 and phthalide 6 showed potent antioxidant activity.

Topics: Antineoplastic Agents; Antioxidants; Aromatase Inhibitors; Benzofurans; Biphenyl Compounds; Colletotrichum; Drug Screening Assays, Antitumor; Free Radical Scavengers; Hep G2 Cells; HL-60 Cells; Humans; Isocoumarins; Lactones; Molecular Structure; Picrates; Piper; Structure-Activity Relationship; Thailand

This research communication is toward the investigation of the antibacterial, antifungal and antioxidant activities of the synthesized compounds 1-(4'-O-β-D-glucopyranosyloxy-2'-hydroxyphenyl)-3-aryl-propane-1,3-diones (5a)-(5h). These compounds have been obtained by the interaction of α-acetobromoglucose with 1-(2',4'-dihydroxyphenyl)-3-aryl-propane-1,3-diones (3a)-(3h) under anhydrous condition and at lower temperature. The structures of these newly synthesized O-β-D-glucopyranosides were established on the basis of chemical, elemental, and spectral analyses. Further, the compounds (5b), (5c), (5d) and (5g) showed potent antibacterial and antifungal activity. A good correlation was obtained between the theoretical predictions of bioavailability using Lipinski's rule-of-five and experimental verification.

Topics: Anti-Infective Agents; Bacteria; Biphenyl Compounds; Free Radical Scavengers; Ketones; Picrates; Spectrum Analysis

The reactivity of ketene dithiolates in the presence of different equivalents of sodium ethoxide was studied. 2-(Bis((5-aryl-1,3,4-oxadiazol-2-yl)methylthio)methylene)malononitriles 5 and 2-(bis((5-aryl-1,3,4-thiadiazol-2-yl)methylthio)methylene)malononitriles 6 were prepared by the reaction of malononitrile with carbon disulfide and 5-aryl-2-(chloromethyl)-1,3,4-oxadiazoles 3/5-aryl-2-(chloromethyl)-1,3,4-thiadiazoles 4. The preliminary antimicrobial and antioxidant activities of the lead compounds were assayed.

Topics: Anti-Infective Agents; Bacteria; Biphenyl Compounds; Free Radical Scavengers; Fungi; Microbial Sensitivity Tests; Nitriles; Picrates

In order to develop potent skin whitening agents, we have synthesized 17 hydroxyphenyl benzyl ether compounds and tested their melanin synthesis inhibitory activity, DPPH free radical scavenging activity and tyrosinase inhibitory activity. Compounds 32, 35 and 36 possessing 4-hydroxyphenyl benzyl ether structure showed excellent inhibitory capacity with almost 50-fold than arbutin used as a reference in the inhibition test of α-MSH stimulated melanin synthesis in B-16 cells. 4-Hydroxyphenyl benzyl ether compounds also showed good antioxidant activity in the DPPH free radical scavenging test. The tyrosinase function was effectively inhibited by 3,5-dihydroxyphenyl benzyl ether analogues, especially compounds 18, 22, and 24.

Topics: alpha-MSH; Antioxidants; Benzyl Compounds; Biphenyl Compounds; Bleaching Agents; Ethers; Free Radical Scavengers; Free Radicals; Humans; Melanins; Melanoma, Experimental; Monophenol Monooxygenase; Phenols; Picrates; Skin Pigmentation

In order to explore the anti-inflammatory principles of the mycelia of Cordyceps sinensis, the crude extract and partially purified fractions were examined for their inhibition of superoxide anion generation and elastase release. Further chemical investigation of the bioactive fractions has resulted in the identification of 50 compounds, including five constituents, cordysinins A-E (1-5), reported from a natural source for the first time. In addition, compounds were examined for their anti-inflammatory activity. 1-(5-Hydroxymethyl-2-furyl)-β-carboline displayed the most significant inhibition of superoxide anion generation and elastase release with IC50 values of 0.45±0.15 and 1.68±0.32 μM, respectively.

Topics: Anti-Inflammatory Agents; Biphenyl Compounds; Carbolines; Cordyceps; Humans; Inhibitory Concentration 50; Molecular Structure; Mycelium; Pancreatic Elastase; Picrates; Stereoisomerism; Superoxides; Taiwan

A new class of oxazolyl/thiazolylsulfonylmethyl pyrazoles (10-13) and isoxazoles (14, 15) were prepared from the synthetically vulnerable intermediate E-styrylsulfonylacetic acid methyl ester (1) and studied their antioxidant activity.

Topics: Antioxidants; Biphenyl Compounds; Free Radicals; Isoxazoles; Nitric Oxide; Oxazoles; Picrates; Pyrazoles; Thiazoles

4-Schiff base-7-benzyloxy-coumarins 5a(1)-5h(2) and its derivative 6 were designed and synthesized based on the 7-benzyloxy-coumarin structure as novel antioxidants. The in vitro antioxidant activities screening revealed that 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activities of compounds 5b(1), 5d(1), 5f(1), 5f(2), 5g(1) and 5g(2), and 2,2'-azinobis-(3-ethylbenzthiazoline-6-sulfonate) cation (ABTS(+)) radical scavenging activities of compounds 5a(1), 5b(1), 5c(1), 5c(2), 5d(1), 5e(1), 5e(2), 5f(2), 5g(1), 5g(2) and 5h(1) were better than that of the commercial antioxidant butylated hydroxytoluene (BHT), while the superoxide anion radical scavenging activities of 5a(2) and 5g(2) were stronger than that of the commercial antioxidant butylated hydroxyanisole (BHA), and the hydroxyl radical scavenging activity of 5e(1) was much better than that of the common antioxidant ascorbic acid.

Topics: Benzothiazoles; Biphenyl Compounds; Coumarins; Free Radical Scavengers; Free Radicals; Picrates; Schiff Bases; Sulfonic Acids; Superoxides; Thiazoles

Vanillin, a compound widely used in foods, beverages, cosmetics and drugs, has been reported to exhibit multifunctional effects such as antimutagenic, antiangiogenetic, anti-colitis, anti-sickling, and antianalgesic effects. However, results of studies on the antioxidant activity of vanillin are not consistent.. We systematically evaluated the antioxidant activity of vanillin using multiple assay systems. DPPH radical-, galvinoxyl radical-, and ABTS(+)-scavenging assays, ORAC assay and an oxidative hemolysis inhibition assay (OxHLIA) were used for determining the antioxidant activity.. Vanillin showed stronger activity than did ascorbic acid and Trolox in the ABTS(+)-scavenging assay but showed no activity in the DPPH radical- and galvinoxyl radical-scavenging assays. Vanillin showed much stronger antioxidant activity than did ascorbic acid and Trolox in the ORAC assay and OxHLIA. In the ABTS(+)-scavenging assay, ORAC assay and OxHLIA, vanillin reacted with radicals via a self-dimerization mechanism. The dimerization contributed to the high reaction stoichiometry against ABTS(+) and AAPH-derived radicals to result in the strong effect of vanillin. Oral administration of vanillin to mice increased the vanillin concentration and the antioxidant activity in plasma. These data suggested that antioxidant activity of vanillin might be more beneficial than has been thought for daily health care.. Based on the results of the present study, we propose the addition of antioxidant capacity to the multifunctionality of vanillin.

Topics: Animals; Antioxidants; Ascorbic Acid; Benzaldehydes; Benzhydryl Compounds; Benzothiazoles; Biphenyl Compounds; Chromans; Chromatography, High Pressure Liquid; Dose-Response Relationship, Drug; Drug Evaluation, Preclinical; Erythrocytes; Free Radical Scavengers; Hemolysis; Mice; Molecular Structure; Oxidation-Reduction; Picrates; Sheep; Sulfonic Acids

A semiquinone glucoside derivative (SQGD) was isolated from a radioresistant bacterium Bacillus sp. INM-1 and its antioxidant and radioprotective activities were evaluated using in vitro assays. Natural stable free radical properties of SQGD in solid as well as in solution form were estimated using Electron Paramagnetic Resonance (EPR) spectrometry. Results of the study were demonstrated high reducing power (1.267 ± 0.03356 U(abs)) and nitric oxide radicals scavenging activity (34.684 ± 2.132%) of SQGD. Maximum lipid peroxidation inhibitory activity of SQGD was found to be 74.09 ± 0.08% at 500 μg/ml concentration. Similarly, significant (39.54%; P < 0.05) protection to the liposomal artificial membrane against gamma radiation was observed by SQGD in terms of neutralization of gamma radiation-induced TBARS radicals in vitro. OH(-) radicals scavenging efficacy of SQGD was estimated in terms of % inhibition in deoxy D: -ribose degradation by non-site-specific and site-specific assay. The maximum (54.01 ± 1.01%) inhibition of deoxy D: -ribose degradation was observed in non-site-specific manner, whereas, site-specific inhibition was observed to be 46.36 ± 0.5% at the same concentration (250 μg/ml) of SQGD. EPR spectroscopic analysis of the SQGD indicated ~80% reduction of DPPH radicals at 6.4% concentration. EPR spectral analysis of SQGD was revealed an appearance of very strong EPR signal of 2.00485 (crystalline form) and 2.00520 (solution form) g(y) tensor value, which were an established characteristic of o-semiquinone radicals. Therefore, it can be concluded that SQGD is a natural stable o-semiquinone-type radical, possessing strong antioxidant activities and can effectively neutralize radiation induced free radicals in biological system.

Topics: Antioxidants; Ascorbic Acid; Bacillus; Benzothiazoles; Biphenyl Compounds; Electron Spin Resonance Spectroscopy; Free Radical Scavengers; Glucosides; Hydroxyl Radical; Lipid Peroxidation; Liposomes; Nitric Oxide; Oxidation-Reduction; Picrates; Radiation-Protective Agents; Sulfonic Acids

This study reports the antioxidant and antibacterial activities of four fresh mango seed extracts from Thai varieties. Total phenol contents determined by the Folin-ciocalteu method revealed the highest values to be in MKE, Chok-a-nan variety (399.8 mgGAE/g extract) and MSE of Nam-dok-mai variety (377.2 mgGAE/g extract). Both extracts showed potent ABTS˙+ radical and DPPH˙ radical scavenging activities with the lower half inhibition concentration (IC50) values than those of the reference compounds; vitamin C, trolox and BHA, respectively. Their antioxidant property of MSE and MKE is strongly correlated with the total phenol contents (r=0.98 and 0.98, respectively). When combined the MSE and MKE of the Fah-lun variety showed the strongest antioxidant activity. All mango seed extracts showed interesting antibacterial activity against both gram positive and gram negative bacteria as determined by disc diffusion method. The most sensitive pathogenic strain inhibited by all extracts (especially Kaew variety) was Pseudomonas aeruginosa ATCC 27853. This work suggests potential applications for practical uses of mango seed extracts from Thai varieties, as sources of antioxidant and antibacterial agents.

Topics: Anti-Bacterial Agents; Antioxidants; Ascorbic Acid; Bacteria; Benzothiazoles; Biphenyl Compounds; Chromans; Diffusion; Free Radical Scavengers; Indicators and Reagents; Mangifera; Microbial Sensitivity Tests; Phenols; Picrates; Plant Extracts; Seeds; Sulfonic Acids; Thailand

Leucosidea sericea is an important medicinal plant widely used in traditional medicine in southern Africa. Leaf and stem petroleum ether (PE), dichloromethane (DCM) and 50% aqueous methanol (MeOH) extracts were investigated for antioxidant and acetylcholinesterase inhibitory activities. The safety of the extracts was evaluated using the Ames test. In addition, the iridoid content of L. sericea stems and leaves were quantified. For DPPH radical-scavenging activity, the stem MeOH extract (EC(50) value: 1.6 μg/ml) was more potent than ascorbic acid (EC(50) value: 1.7 μg/ml). In the β-carotene-linoleic acid model system, antioxidant activity of the leaf DCM extract (89.8%) was not significantly different to that of butylated hydroxytoluene (BHT) (98.9%). All extracts showed a dose-dependent acetylcholinesterase inhibition; in terms of the IC(50) value, the leaf DCM extract (0.14 mg/ml) was the most potent sample. Total iridoid content was 35% higher in the stem extract than in the leaf extract. Based on the Ames test, L. sericea extracts were not mutagenic, either with or without S9 metabolic activation. These findings suggest the safety as well as the potential of L. sericea as a possible source of novel/alternative antioxidant and acetylcholinesterase inhibitory compounds.

Topics: Analysis of Variance; Antioxidants; Ascorbic Acid; Biphenyl Compounds; Cholinesterase Inhibitors; Drug-Related Side Effects and Adverse Reactions; Iridoids; Medicine, African Traditional; Mutagens; Picrates; Plant Extracts; Plant Leaves; Plant Stems; Plants, Medicinal; Rosaceae

The aim of the study was to investigate antioxidant activities of Ganoderma lucidum and Funalia trogii. Ethanol and water crude extracts from G. lucidum and F. trogii were investigated for their antioxidant capacity in some different assays, namely, the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity, metal chelating activity against ferrous ions, and plasma lipid peroxidation inhibitory. In addition, the amounts of total phenol, ascorbic acid, β-carotene, and lycopene components in the extracts were determined. Among the four mushroom extracts, G. lucidum water extract and G. lucidum ethanol extract showed the highest scavenging activity against DPPH radicals (50% inhibitory concentration = 0.055 ± 0.001 mg/mL). Total phenol was the major antioxidant component found in the mushroom extracts. These results showed that G. lucidum may be used in pharmaceutical applications because of its effective antioxidant properties.

Topics: Ascorbic Acid; beta Carotene; Biphenyl Compounds; Carotenoids; Chelating Agents; Chromatography, High Pressure Liquid; Coriolaceae; Ferrous Compounds; Free Radical Scavengers; Lipid Peroxidation; Lycopene; Phenols; Picrates; Reishi

The seeds of C. sativum are used as a traditional drug for the treatment of diabetes. The antioxidant and free-radical-scavenging property of seeds in vitro was studied and also investigated whether the administration of seeds curtails oxidative stress in the kidney of streptozotocin-induced diabetic rats. Incorporation of seed powder in the diet led to marked lowering of blood glucose and a rise in the levels of insulin in diabetic rats. A parallel beneficial effect was observed on oxidant -antioxidant balance in the kidney. Addition of coriander seed powder not only inhibited the process of peroxidative damage but also significantly reactivated the antioxidant enzymes and antioxidant levels in diabetic rats. The total polyphenolic content of the seeds was found to be 12.2 gallic acid equivalents (GAE)/g while total flavanoid content was found to be 12.6 quercetin equivalents/g. The seeds also showed scavenging activity against superoxides and hydroxyl radicals in a concentration-dependent manner. Maximum free radical-scavenging action and free radical reducing power of coriander seed extract was observed at a concentration of 50 microg GAE. Islet histology structures showed degeneration of pancreatic islets in diabetic rats which was also reduced in diabetic rats treated with seed powder. These results show that C. sativum seeds not only possess antihyperglycemic properties but antioxidative properties also. Increased dietary intake of coriander seeds decrease the oxidative burden in diabetes mellitus.

Topics: Animals; Antioxidants; Ascorbic Acid; Biphenyl Compounds; Blood Glucose; Coriandrum; Diabetes Mellitus, Experimental; Fasting; Free Radical Scavengers; Gallic Acid; Glutathione; Glycated Hemoglobin; Insulin; Islets of Langerhans; Kidney; Lipid Peroxidation; Male; Oxidation-Reduction; Phytotherapy; Picrates; Plant Extracts; Protein Carbonylation; Rats; Seeds; Superoxides; Thiobarbituric Acid Reactive Substances; Vitamin E

Phytochemicals such as polyphenols and carotenoids are gaining importance because of their contribution to human health and their multiple biological effects such as antioxidant, antimutagenic, anticarcinogenic, and cytoprotective activities and their therapeutic properties. Banana peel is a major by-product in pulp industry and it contains various bioactive compounds like polyphenols, carotenoids, and others. In the present study, effect of ripening, solvent polarity on the content of bioactive compounds of crude banana peel and the protective effect of peel extracts of unripe, ripe, and leaky ripe banana fruit on hydrogen peroxide-induced hemolysis and their antioxidant capacity were investigated. Banana (Musa paradisica) peel at different stages of ripening (unripe, ripe, leaky ripe) were treated with 70% acetone, which were partitioned in order of polarity with water, ethyl acetate, chloroform (CHCl₃), and hexane sequentially. The antioxidant activity of the samples was evaluated by the red cell hemolysis assay, free radical scavenging (1,1-diphenyl-2-picrylhydrazyl free radical elimination) and superoxide dismutase activities. The Folin-Ciocalteu's reagent assay was used to estimate the phenolic content of extracts. The findings of this investigation suggest that the unripe banana peel sample had higher antioxidant potency than ripe and leaky ripe. Further on fractionation, ethyl acetate and water soluble fractions of unripe peel displayed high antioxidant activity than CHCl₃ and hexane fraction, respectively. A positive correlation between free radical scavenging capacity and the content of phenolic compound were found in unripe, ripe, and leaky ripe stages of banana peel.

Topics: Antioxidants; Ascorbic Acid; Biotechnology; Biphenyl Compounds; Erythrocytes; Flavonoids; Food Handling; Free Radical Scavengers; Free Radicals; Fruit; Hemolysis; Humans; Musa; Oxidation-Reduction; Phenols; Picrates; Plant Extracts; Polyphenols; Solvents; Superoxide Dismutase

Extracts of Indonesian medicinal plants, Murraya koenigii, Syzygium polyanthum, and Zingiber purpurea were investigated for their biological activity. The presence of phytochemicals, cytotoxicity, and antimicrobial and antioxidant activities were investigated. Parts of M. koenigii, S. polyanthum, and Z. purpurea were extracted with ethanol. The extracts were evaluated for antimicrobial activity using the disc diffusion method, while antioxidant activity was determined with a 1,1-diphenyl-2-picrylhydrazyl radical scavenging assay. Cytotoxicity was investigated using the brine shrimp lethality test, and phytochemical screening was performed using a standard method. M. koenigii leaf extract exhibited the most activity in the test microorganism activity index (AI), 0.38-1.25, when compared with standard drugs. S. polyanthum ripened fruit displayed significant antioxidant activity (90%) in comparison to ascorbic acid (95%). Z. purpurea rhizome extract possessed the highest cytotoxic effect with a LC(50) of 52 μg/mL. Phytochemical analysis revealed that carbohydrate, tannin, alkaloid, steroid, triterpenoid, and flavonoid were present in the extracts of M. koenigii leaves and twigs, S. polyanthum leaves and ripened and unripe fruits, and Z. purpurea rhizome, while saponin was only present in the S. polyanthum ripened fruit extract. Our work revealed that the M. koenigii leaves, S. polyanthum ripened fruit, and Z. purpurea rhizome extracts have potential as sources of new antimicrobial, antioxidant, and cytotoxic compounds, respectively.

Topics: Animals; Anti-Infective Agents; Antioxidants; Artemia; Ascorbic Acid; Biphenyl Compounds; Cytotoxins; Indonesia; Microbial Sensitivity Tests; Murraya; Picrates; Plant Extracts; Plant Structures; Plants, Medicinal; Syzygium; Zingiberaceae

Genotoxic and antigenotoxic effects of acerola fruit at two stages of ripeness were investigated using mice blood cells. The results show that no ripeness stage of acerola extracts presented any genotoxic potential to damage DNA (Comet assay) or cytotoxicity (MTT assay). When antigenotoxic activity was analyzed, unripe fruit presented higher DNA protection than ripe fruit (red color) extract. The antioxidant capacity of substances also showed that unripe samples inhibit the free radical DPPH more significantly than the ripe ones. The results about determination of compounds made using HPLC showed that unripe acerola presents higher levels of vitamin C as compared to ripe acerola. Thus, vitamin C and the complex mixture of nutrients of Malpighia glabra L., and especially its ripeness stages, influenced the interaction of the fruit extract with the DNA. Acerola is usually consumed when ripe (red fruit), although it is the green fruit (unripe) that has higher potential as beneficial to DNA, protecting it against oxidative stress.

Topics: Animals; Antimutagenic Agents; Antioxidants; Ascorbic Acid; Biphenyl Compounds; Chromatography, High Pressure Liquid; Comet Assay; Cytotoxicity Tests, Immunologic; DNA Damage; Free Radicals; Fruit; Leukocytes; Male; Malpighiaceae; Mice; Oxidative Stress; Picrates; Plant Extracts

The phytochemical composition of carotenoids, tocopherols, free sugars, organic acids, L-ascorbic acid, capsaicinoids, and flavonoids in green and red paprika (GP and RP), and paprika leaves (PL) cultivated in Korea were analyzed. The ethanolic extracts of GP, RP, and PL were obtained with 80% ethanol, and their antioxidative activities were determined by measuring their ABTS and DPPH radical scavenging activities. RP showed the highest contents of capsanthin (58.33 ± 3.91 mg/100 g dry weight) and L-ascorbic acid (1987.25 ± 19.64 mg/100 g dry weight), and main compounds of PL were lutein, chlorophyll, and γ-tocopherol (96.91 ± 14.58, 2136.71 ± 21.11, and 723.49 ± 54.10 mg/100 g dry weight, respectively). RP showed the strongest antioxidant activity (IC(50) = 55.23 ± 6.77 μg/mL in a 2, 2'-azino-di-[3-ethylbenzthiazoline sulphonate] assay and 150.40 ± 8.07 μg/mL in a 2, 2-diphenyl-2-picrylhydrazyl assay), and the antioxidant activity of PL was higher than β-carotene but lower than RP. The results indicate that the amounts of capsanthin and L-ascorbic acid in RP correlate well with antioxidant activity. PL, which has various phytochemicals such as lutein, chlorophyll, and γ-tocopherol, might be used in nutraceuticals and pharmaceuticals for improving human health.

Topics: Antioxidants; Ascorbic Acid; Benzothiazoles; Biphenyl Compounds; Capsicum; Carotenoids; Chlorophyll; Flavonoids; Fruit; gamma-Tocopherol; Lutein; Picrates; Plant Leaves; Republic of Korea; Sulfonic Acids; Xanthophylls

The effects of salicylic acid (SA) on the quality and antioxidant activity of asparagus stored at 18 ± 2 °C were investigated by analyzing the color, chlorophyll, shear force, and the activity of antioxidant compounds such as ascorbic acid, phenolics, flavonoids, 1,1-Diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity ferric reducing antioxidant power (FRAP), and polyamines (PAs). The results showed that SA improved the color and maintained the chlorophyll, phenolic, flavonoid, and ascorbic acid content of asparagus. High concentrations of SA caused a deterioration in asparagus would harm to color and had no effect on shear force within 6 d. SA induced the maximum concentration of phenolics in postharvest asparagus, promoted the increase in total flavonoids before 6 to 9 d, affected the antioxidant activity positively as indicated by the resultant increase in FRAP concentration; however, SA was only active with regard to DPPH scavenging activity within 6 d of treatment. Spermidine (Spd) is the most common form of PA in asparagus, and free putrescine (Put) contents increased over the first 3 d following harvest and then decreased. Spd and Spm concentrations evolved in a similar way and decreased during storage. Higher Spd and Spm contents in the SA pre-treatment Put was inhabited and its peaks appeared later.

Topics: Ascorbic Acid; Asparagus Plant; Biphenyl Compounds; Dose-Response Relationship, Drug; Flavonoids; Food Preservation; Food Technology; Free Radical Scavengers; Phenols; Picrates; Pigmentation; Polyamines; Quality Control; Salicylic Acid; Vegetables

Cellular damage induced by free-radicals like Reactive Oxygen and Nitrogen Species (ROS and RNS) has been implicated in several disorders and diseases, including ageing. Hence naturally occurring anti-oxidant rich-herbs play a vital role in combating these conditions. The present study was carried out to investigate the in vitro free-radical quenching capacity of a known Ayurvedic poly-herbal formulation called Vayasthapana Rasayana.. Methanol extracts of Vayasthapana Rasayana formulation (VRF) were studied for in vitro total antioxidant activity along with phenolic content and reducing power. In vitro assays like DPPH, FRAP, ABTS scavenging to evaluate radical quenching potential were performed.. The formulation has shown 94% at 0.1 mg/ml DPPH free-radical scavenging activity as against 84% at 0.1 mg/ml for standard ascorbic acid (IC₅₀ value 5.51 μg/ml for VRF and 39 μg/ml for standard). It has a significant higher ferric reducing potential also (OD 0.87 at 700 nm & 0.21 at 0.1 mg/ml for VRF and standard, respectively). The total phenolic content (gallic acid equivalent) of the VRF is 8.3 mg per g of dry mass. Total antioxidant capacity of the formulation, estimated by FRAP was 1150 ± 5 μM Fe(II)/g dry mass. ABTS radical scavenging activity of VRF was 69.55 ± 0.21% at 100 μg/ml concentration with a IC50 value of 69.87 μg/ml as against 9% and 95% by ascorbic acid and Trolox (at 70.452 μg/ml and 0.250 μg/ml concentrations, respectively).. In Indian traditional Ayurvedic system, use of VRF is in regular practice for mainly combating age-related disorders and diseases as many of the components of the Rasayana are known for their free-radical scavenging activity. This study has validated the potential use of VRF as an anti-oxidant to fight age-related problems.

Topics: Aging; Antioxidants; Ascorbic Acid; Benzothiazoles; Biphenyl Compounds; Chromans; Ferric Compounds; Humans; Magnoliopsida; Medicine, Ayurvedic; Oxidative Stress; Phenols; Picrates; Plant Extracts; Reference Standards; Sulfonic Acids; Thiazoles

Leucoagaricus leucothites (Vittad.) Wasser is an edible macrofungus found limitedly in Turkey. The ethanolic extract of L. leucothites has shown strong antimicrobial activity against some foodborne and spoilage bacteria. Therefore, the phenolic composition of L. leucothites ethanolic extract was analyzed by using high-performance liquid chromatography. Catechin (288 mg/L) was found to be the major component in the extract. Antioxidant activity of the extract was evaluated by studying the scavenging ability of 2,2-diphenyl-1-picrylhydrazyl (DPPH) radicals, and chelating ability of the extract was assessed in a ferrous ion assay. The scavenging effect on DPPH radicals was 71% at 10 mg/mL, whereas the chelating effect on ferrous ions was 82% at 15 mg/mL. The total contents of phenol (3.40 ± 0.5 mg/g), ascorbic acid (2.10 ± 0.3 mg/g), β-carotene (0.02 ± 0.0 mg/g), and lycopene (0.01 ± 0.0 mg/g) in the macrofungi ethanolic extract were also determined.

Topics: Agaricales; Anti-Infective Agents; Antioxidants; Ascorbic Acid; Bacteria; beta Carotene; Biphenyl Compounds; Carotenoids; Catechin; Chromatography, High Pressure Liquid; Ethanol; Lycopene; Phenols; Picrates

The extraction conditions of polysaccharides from Plantago asiatica L. seeds were investigated. Four parameters affecting the polysaccharides extraction, extraction times, water to sample, extraction temperature and single extraction time, were determined by orthogonal experiments. Under the optimized conditions, the polysaccharides yield of P. asiatica L. seeds was 2.467%. The antioxidant activities of the polysaccharides were investigated. The reducing power of the polysaccharides was dose dependent, and the reducing capacity of the polysaccharides was inferior to butylated hydroxytoluene, which is known to be a strong reducing agent. The scavenging rates of the polysaccharides on superoxide and 1,1-diphenyl-2-picrylhydrazyl radicals were 79.7% and 81.4%, at polysaccharides concentration of 0.75 mg/mL, respectively, a scavenging rates approximately similar to that of 0.75 mg/mL ascorbic acid (83.5% and 85.1%, respectively). Furthermore, it exhibited a moderate concentration-dependent ABTS radical scavenging activity, ferrous ion chelating potency and H(2)O(2) scavenging activity. The data obtained in the in vitro models clearly establish the antioxidant potency of the polysaccharides extracted from Semen Plantaginis.

Topics: Antioxidants; Ascorbic Acid; Benzothiazoles; Biphenyl Compounds; Butylated Hydroxytoluene; Chelating Agents; Chemical Fractionation; Edetic Acid; Free Radical Scavengers; Hydrogen Peroxide; Oxidation-Reduction; Picrates; Plantago; Polysaccharides; Seeds; Sulfonic Acids; Superoxides

The present study was undertaken to determine the optimum effective dose, dose reduction factor (DRF) and possible mechanism of action of Aloe gel. Three different doses of gel (250, 500 and 750 mg/kg body weight) were tested against 8 Gy induced damage in Swiss albino mice. A dose of 750 mg/kg body weight of Aloe was found the most effective while, 250 mg/kg body weight was the least effective in providing protection, as observed in the form of higher concentrations of blood GSH and vitamin C and lower level of serum LPO than irradiated animals at 1h post irradiation and higher percent of survivors up to day 30 post irradiation. Treatment of mice with Aloe before irradiation with different doses of gamma radiation (6-12 Gy) delayed the onset and reduced the severity of signs of radiation sickness. The LD(50/30) was calculated as 6.77 and 10 Gy for untreated irradiated and Aloe treated irradiated animals, respectively and its dose reduction factor was also calculated as 1.47. Aloe gel scavenged the free radicals, DPPH•, ABTS(+•) and NO in a concentration dependent manner in vitro and therefore, scavenging of free radicals seems to be its important mechanism of action.

Topics: Aloe; Animals; Antioxidants; Ascorbic Acid; Benzothiazoles; Biphenyl Compounds; Dose-Response Relationship, Drug; Free Radical Scavengers; Gels; Glutathione; Lethal Dose 50; Lipid Peroxidation; Male; Mice; Nitric Oxide; Picrates; Radiation Injuries; Radiation-Protective Agents; Sulfonic Acids

Ramalin (γ-glutamyl-N'-(2-hydroxyphenyl)hydrazide), a novel compound, was isolated from the methanol-water extract of the Antarctic lichen Ramalina terebrata by several chromatographic methods. The molecular structure of ramalin was determined by spectroscopic analysis. The experimental data showed that ramalin was five times more potent than commercial butylated hydroxyanisole (BHA) in scavenging 1-diphenyl-2-picryl-hydazil (DPPH) free radicals, 27 times more potent in scavenging 2,2'-azino-bis (3-ethylbenzthiazoline-6-sulfonic acid free radicals (ABTS(+)) than the vitamin E analogue, trolox, and 2.5 times more potent than BHT in reducing Fe(3+) to Fe(2+) ions. Similarly, ramalin was 1.2 times more potent than ascorbic acid in scavenging superoxide radicals and 1.25 times more potent than commercial kojic acid in inhibiting tyrosinase enzyme activity, which ultimately leads to whitening of skin cells. Ramalin showed no or very little cytotoxicity in human keratinocyte and fibroblast cells at its antioxidant concentration. Furthermore, ramalin was assessed to determine its antioxidant activity in vivo. One microgram per milliliter ramalin significantly reduced the released nitric oxide (NO) and 0.125 μg/ml ramalin reduced the produced hydrogen peroxide (H(2)O(2)) in LPS (lipopolysaccharide)-stimulated murine macrophage Raw264.7 cells. Considering all the data together, ramalin can be a strong therapeutic candidate for controlling oxidative stress in cells.

Topics: Animals; Antarctic Regions; Antioxidants; Ascorbic Acid; Benzothiazoles; Biphenyl Compounds; Butylated Hydroxyanisole; Cell Line; Cell Survival; Chromans; Fibroblasts; Free Radicals; Fungal Proteins; Glutamates; Humans; Hydrogen Peroxide; Keratinocytes; Lichens; Mice; Molecular Structure; Monophenol Monooxygenase; Nitric Oxide; Picrates; Pyrones; Sulfonic Acids

A new neolignan, 3,4-dimethoxy-3',4'-methylenedioxy-2,9-epoxy-6,7-cyclo-1,8-neolign-11-en-5(5H)-one, which has been named (+)-kunstlerone (1), together with six known alkaloids: (+)-norboldine (2), (+)-N-methylisococlaurine (3), (+)-cassythicine (4), (+)-laurotetanine (5), (+)-boldine (6) and (-)-pallidine (7), were isolated from the leaves of Beilschmiedia kunstleri. The structures were established through various spectroscopic methods notably 1D- and 2D-NMR, UV, IR and LCMS-IT-TOF. (+)- Kunstlerone (1) showed a strong antioxidant activity, with an SC(50) of 20.0 µg/mL.

Topics: Alkaloids; Antioxidants; Ascorbic Acid; Biphenyl Compounds; Chemistry, Pharmaceutical; Chromatography, Liquid; Free Radicals; Lauraceae; Lignans; Magnetic Resonance Spectroscopy; Malaysia; Mass Spectrometry; Models, Molecular; Picrates; Plant Leaves

Flos trollii is considered as functional tea, as well as a traditional medicinal herb, in China. In this study, total phenolic and flavonoid contents of Flos trollii were determined by a colorimetric method. The antioxidative potential of the hydroalcoholic extract of Flos trollii (FTE, extracted by alcohol:water, 80:20) was also evaluated by various antioxidant assays.. Chemiluminescence technique was used to determine the radical scavenging activities of FTE toward different reactive oxygen species, including superoxide anion (O(-2)·), hydroxyl radical (OH·), lipid-derived radicals (R·), and singlet oxygen ((1)O(2)).. FTE could effectively scavenge O(-2)·, OH·, R·, and (1)O(2) at an efficient concentration (EC(50)) of 46, 5.64, 5.19, and 3.97 mg/mL, respectively. Moreover, the radical scavenging activities of FTE were higher than those of ascorbic acid. Further, FTE had higher 1,1 diphenyl-2-picrylhydrazyl radical (DPPH) radical-scavenging activity with EC(50) 44 mg/mL, compared with butylated hydroxytoluenesynthetic antioxidant with EC(50) 52 mg/mL.. All results indicated that FTE is a powerful antioxidant, deserving of better utilization of the extracted Flos trollii as antioxidants.

Topics: Ascorbic Acid; Biphenyl Compounds; Colorimetry; Flavonoids; Flowers; Free Radical Scavengers; Phenols; Picrates; Ranunculaceae; Reactive Oxygen Species

Research on natural and bioactive compounds is increasingly focused on their effects on human health, but there are unexpectedly few studies evaluating the relationship between climate and natural antioxidants. The aim of this study was analyze the biological role of six different Brassica vegetables (Brassica oleracea L. and Brassica rapa L.) as a natural source of antioxidant compounds. The antioxidant activity may be assigned to high levels of L-ascorbic acid, total phenolics and total flavonoids of each sample. The climate seasons affected directly the concentration of bioactive components and the antioxidant activity. Broccoli inflorescences and Portuguese kale showed high antioxidant activity in Spring-Summer whilst turnip leaves did so in Summer-Winter. The Brassica vegetables can provide considerable amounts of bioactive compounds and thus may constitute an important natural source of dietary antioxidants.

Topics: Antioxidants; Ascorbic Acid; Biphenyl Compounds; Brassicaceae; Chromatography, High Pressure Liquid; Diet; Flavonoids; Free Radicals; Humans; Phenols; Picrates; Plant Extracts; Plant Leaves; Principal Component Analysis; Reactive Oxygen Species; Seasons; Temperature; Water

The antioxidant properties of sulfur-containing substances have been experimentally studied in vitro. Unithiol exhibits a wide spectrum us radicals. For this reason, unithiol can be considered, along with ascorbic acid, as a universal drug for the reduction of free radical reactions.

Topics: Antioxidants; Ascorbic Acid; Biphenyl Compounds; Chelating Agents; Free Radicals; Hydrogen Peroxide; Iron; Oxidation-Reduction; Oxidative Stress; Picrates; Solutions; Spectrophotometry; Sulfur; Thiosulfates; Unithiol

This study evaluated the antioxidant activity as well as bioflavonoid content of the methanol and ethanol-water extracts of the fresh and dried leaves of Tetracarpidium conophorum. Antioxidant activity was determined by spectrophotometric methods using DPPH free radical, nitric oxide radical inhibition and ferric reducing antioxidant power assays. In addition, total phenolics, flavonoids and proanthocyanidin content were also determined. The ethanol: water extract of the dried leaves had the highest antioxidant activity with a 50% inhibition of DPPH at a concentration of 0.017 mg/mL compared to the standards, Vitamin C and Vitamin E with inhibition of 0.019 and 0.011 mg/mL, respectively. This extract also showed nitric oxide radical inhibition activity comparable to that of rutin, 54.45% and 55.03% for extract and rutin, respectively, at 0.1 mg/mL. Ferric reducing power was also comparable to that of ascorbic acid (281 and 287 μM Fe (11)/g, resp.) at a concentration of 1 mg/mL. The methanol extract of both the dried and the fresh leaves had higher phenolic, flavonoids and proanthocyanidin content than the ethanol:water extract. The study reveals that T. conophorum can be an interesting source of antioxidants with their potential use in different fields namely food, cosmetics and pharmaceuticals.

Topics: Antioxidants; Ascorbic Acid; Biphenyl Compounds; Euphorbiaceae; Picrates; Plant Leaves; Vitamin E

Cadmium (Cd) is ubiquitous in the environment and exposure through food and water as well as occupational sources can contribute to a well-defined spectrum of disease. The present study was undertaken to evaluate the role of hesperetin (Hp) in alleviating the Cd induced biochemical changes in rats.. During the experiment, male Wistar rats were injected with Cd 83 mg/kg day) subcutaneously alone or with oral administration of Hp 840 mg/kg day) for 21 days.. In Cd treated rats the levels of plasma lipid peroxidation (LPO) markers: thiobarbituric acid reactive substances (TBARS) and lipid hydroperoxides (LOOH) were significantly increased while the levels of plasma non-enzymatic antioxidants: reduced glutathione (GSH), vitamins C and E were significantly decreased in Cd administered rats. Administration of Hp along with Cd significantly decreased the level of LPO markers with elevation of non-enzymatic antioxidants in plasma. In vitro studies on the effect of Hp on scavenging 1,1-diphenyl-2-picrylhydrazyl (DPPH*), 2,2-azinobis-(3-ethyl-benzothiazoline-6-sulfonic acid) (ABTS+), superoxide anion (O*-), hydroxyl (OH*) radicals and reducing power also confirmed the free radical scavenging and antioxidant activity of Hp. In addition to that, ascorbic acid, butylated hydroxyl toluene was used as the reference antioxidant radical scavenger compounds. Thus, the observed effects are due to the free radical scavenging and antioxidant potential of Hp. Interestingly, among the different concentrations, tested 50 microM of Hp showed the highest antioxidant and free radical scavenging activities when compared to other concentrations.. The result of these findings provides further evidence to the neutraceutical and pharmaceutical potentials of Hp.

Topics: Administration, Oral; Animals; Antioxidants; Ascorbic Acid; Benzothiazoles; Biomarkers; Biphenyl Compounds; Cadmium Chloride; Dose-Response Relationship, Drug; Environmental Pollutants; Glutathione; Hesperidin; Hydroxyl Radical; Injections, Subcutaneous; Lipid Peroxidation; Lipid Peroxides; Male; Oxidative Stress; Picrates; Rats; Rats, Wistar; Sulfonic Acids; Thiobarbituric Acid Reactive Substances; Vitamin E

To evaluate in vitro antimicrobial and antioxidant activities of methanolic extract of Jasminum humile (J. humile) leaves extract.. Methanolic extract of J. humile was evaluated for its antimicrobial activity by using agar well diffusion method & their possible antioxidant assay by two complementary test systems, namely DPPH and hydrogen peroxide scavenging activity. These various antioxidant activities were compared to standard antioxidants such as ascorbic acid for both the tests.. In the DPPH & hydrogen peroxide scavenging activity, the IC(50) value of methanol extract was 70.43 μg/mL & 60.79 μg/mL respectively. Further, the extract showed inhibitory activity for Gram-positive and negative bacteria at different concentrations. The maximum antibacterial activity of extract was exhibited against Staphylococcus aureus (S. aureus) at concentration 50 mg/mL when compared with ciprofloxacin. These results clearly indicate that J. humile is effective in scavenging free radicals and has the potential to be a powerful antioxidant. Thus, the results obtained in the present study indicate that J. humile leaves extract could be considered as a potential source of natural antioxidants and that could be used as an effective source against bacterial diseases.

Topics: Anti-Infective Agents; Antioxidants; Ascorbic Acid; Biphenyl Compounds; Ciprofloxacin; Dose-Response Relationship, Drug; Free Radicals; Gram-Negative Bacteria; Gram-Positive Bacteria; Humans; Hydrogen Peroxide; Inhibitory Concentration 50; Jasminum; Methanol; Picrates; Plant Extracts; Plant Leaves

The antioxidant activity of two synthesized coumarins namely, N-(4,7-dioxo-2- phenyl-1,3-oxazepin-3(2H,4H,7H)-yl)-2-(2-oxo-2H-chromen-4-yloxy)acetamide 5 and N-(4-oxo-2-phenylthiazolidin-3-yl)-2-(2-oxo-2H-chromen-4-yloxy)acetamide 6 were studied with the DPPH, hydrogen peroxide and nitric oxide radical methods and compared with the known antioxidant ascorbic acid. Compounds 5 and 6 were synthesized in a good yield from the addition reaction of maleic anhydride or mercaptoacetic acid to compound 4, namely N'-benzylidene-2-(2-oxo-2H-chromen-4-yloxy)acetohydrazide. Compound 4 was synthesized by the condensation of compound 3, namely 2-(2-oxo-2H-chromen-4-yloxy) acetohydrazide, with benzaldehyde. Compound 3, however, was synthesized from the addition of hydrazine to compound 2, namely ethyl 2-(2-oxo-2H-chromen-4-yloxy)acetate, which was synthesized from the reaction of ethyl bromoacetate with 4-hydroxycoumarin 1. Structures for the synthesized coumarins 2-6 are proposed on the basis of spectroscopic evidence.

Topics: Antioxidants; Ascorbic Acid; Biphenyl Compounds; Computer Simulation; Coumarins; Free Radical Scavengers; Free Radicals; Hydrogen Peroxide; Models, Chemical; Models, Molecular; Molecular Structure; Nitric Oxide; Oxidation-Reduction; Picrates

Moringa oleifera, Lam. (Moringaceae) is grown world-wide in the tropics and sub-tropics of Asia and Africa and contains abundant various nutrients. This study describes the effect of different parts (leaf, stem and stalk) and seasons (summer and winter) on the chemical compositions and antioxidant activity of M. oleifera grown in Taiwan. The results showed that the winter samples of Moringa had higher ash (except the stalk part), calcium and phenolic compounds (except the leaf part) and stronger antioxidative activity than summer samples. The methanolic extract of Moringa showed strong scavenging effect of DPPH radicals and reducing power. The trend of antioxidative activity as a function of the part of Moringa was: leaf > stem > stalk for samples from both seasons investigated. The Moringa extract showed strong hydrogen peroxide scavenging activity and high Superoxide Dismutase (SOD) activity except the stalk part.

Topics: Antioxidants; Ascorbic Acid; Biphenyl Compounds; Calcium; Free Radical Scavengers; Free Radicals; Hydrogen Peroxide; Methanol; Moringa oleifera; Phenol; Picrates; Plant Extracts; Plant Leaves; Plant Stems; Seasons; Superoxide Dismutase; Taiwan

A series of 5H-dibenz[b,f]azepine containing different aminophenols and substituted aminophenols were synthesized. 3-chloro-1-(5H-dibenz[b,f]azepine-5yl)propan-1-one (2) was obtained by N-acylation of 5H-dibenz[b,f]azepine (1) with 3-chloro propionyl chloride. Further base condensation with different aminophenols and substituted aminophenols to produce series of 5H-dibenz[b,f]azepine containing aminophenol and substituted aminophenol (2a-e). The structures of newly synthesized compounds were characterized by spectral and elemental analysis. Their antioxidant properties were evaluated by using several methods: scavenging effects on 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical, inhibition of lipid peroxidation using beta-carotene linoleate system, inhibition of human low-density lipoprotein (LDL) oxidation and reducing power. Butylated Hydroxy Anisole (BHA) and Ascorbic acid (AA) were used as the reference antioxidant compounds and also the comparative study with the synthesized compounds was done. Under our experimental conditions, Compound (2) showed negligible activity over all the antioxidant assays but 5H-dibenz[b,f]azepine containing different aminophenols and substituted aminophenols (2a-e) showed good antioxidant activities over all the methods and compounds containing substituted aminophenols 2e and 2d showed predominant antioxidant activities among the synthesized analogues.

Topics: Adult; Aminophenols; beta Carotene; Biphenyl Compounds; Carbonates; Dibenzazepines; Free Radical Scavengers; Humans; Lipid Peroxidation; Lipoproteins, LDL; Oxidation-Reduction; Picrates; Potassium

Reaction of benzosuberone 1 with dimethylformamide-dimethylacetal (DMF-DMA) gives 2-dimethylamino-methylenebenozosuberone 2 which in turn reacts with heterocyclic amines to furnish new heterocyclic ring systems 6-9. Moreover, enaminone 2 reacts with hydrazine hydrate and hydroxylamine hydrochloride to afford the corresponding benzo[6,7]cyclohepta[1,2-c]pyrazole (10) and benzo[6,7]cyclohepta[2,1-d]isoxazole (12), respectively. In addition, the reactions of enaminone 2 with active methylene compounds afforded benzo[6,7]cyclohepta[1,2-b]pyridines (13-18). The X-ray crystallographic analysis of compounds 6 and 16, were recorded. We demonstrated the ability of nine new synthesized compounds to inhibit Hepatitis C Virus (HCV) and Subacute Sclerosing Panencephalitis (SSPE) due to structural similarity between ribavirin and some of the newly synthesized compounds were they contain triazoles and its bioisosters. In addition, the ability of ten synthesized compounds to react with the biologically relevant reactive nitrogen species, peroxynitrite was investigated indirectly by measurement of their ability to inhibit ONOO(-)-induced tyrosine nitration. The antioxidant activity of these ten compounds was also studied using 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay.

Topics: Animals; Antioxidants; Antiviral Agents; Biphenyl Compounds; Brain; Cricetinae; Hepacivirus; Heterocyclic Compounds, 2-Ring; Microbial Sensitivity Tests; Peroxynitrous Acid; Picrates; Pyridines; Replicon; Viral Nonstructural Proteins

Synthesis of enone core based dendrimers with carbazole as surface group has been achieved. All the synthesized dendrimers showed excellent antioxidant behavior with commercially available 1,1-diphenyl-2-picryl hydrazyl (DPPH).

Topics: Antioxidants; Biphenyl Compounds; Carbazoles; Dendrimers; Molecular Structure; Picrates; Surface Properties

A new class of sulfone linked pyrrolyl oxazolines and thiazolines were synthesized from E-arylsulfonylethenesulfonylacetic acid methyl ester and studied their antimicrobial and antioxidant activities.

Topics: Anti-Infective Agents; Bacteria; Biphenyl Compounds; Free Radical Scavengers; Fungi; Microbial Sensitivity Tests; Nitric Oxide; Oxazoles; Picrates; Sulfones; Thiazoles

Three new dihydro-beta-agarofuran polyesters, 1alpha,9beta-difuranoyloxy-2-oxodihydro-beta-agarofuran (1), 1alpha,9beta-difuranoyloxy-2-oxo-3-enedihydro-beta-agarofuran (2), and 1alpha,9beta-difuranoyloxydihydro-beta-agarofuran (3), have been isolated from the CHCl(3) extract of the root bark of Osyris lanceolata, together with two known pentacylic triterpenoids, 4 and 5. Compounds 1-5 did not scavenge the DPPH radical within 30 min of reaction time. All five compounds displayed antifungal activity against Candida albicans. Compounds 1, 3, 4, and 5 showed antibacterial activity against the Gram-positive Bacillus subtilis and Staphylococcus aureus and Gram-negative Escherichia coli and Pseudomonas aeruginosa, with 4 and 5 being the most active. Compound 2 displayed weak antibacterial activity only against Escherichia coli.

Topics: Anti-Bacterial Agents; Bacillus subtilis; Biphenyl Compounds; Botswana; Candida albicans; Escherichia coli; Microbial Sensitivity Tests; Molecular Structure; Picrates; Plant Bark; Pseudomonas aeruginosa; Santalaceae; Sesquiterpenes; Staphylococcus aureus; Triterpenes

A new class of oxadiazoles is prepared by treating aminosulfonylacetic acids with different carboxylic acid hydrazides. Interconversion of oxadiazoles to thiadiazoles is carried out with thiourea. The compounds are screened for antimicrobial and antioxidant activities.

Topics: Anti-Infective Agents; Antioxidants; Bacteria; Biphenyl Compounds; Microbial Sensitivity Tests; Nitric Oxide; Oxadiazoles; Picrates; Thiadiazoles

From Veronica longifolia were isolated three chlorinated iridoid glucosides, namely, asystasioside E (6) and its 6-O-esters 6a and 6b, named longifoliosides A and B, respectively. The structures of 6a and 6b were proved by analysis of their spectroscopic data and by conversion to the catalpol ester verproside (5a) or to catalpol (5), respectively. The configuration of the previously known vanilloyl analogue, urphoside B, was shown to be the 6β-epimer (6c) of the structure originally reported. Longifoliosides A (6a) and B (6b) were found to exhibit radical-scavenging activity against nitric oxide, superoxide, and 2,2-diphenyl-1-picrylhydrazyl radicals.

Topics: Antioxidants; Biphenyl Compounds; Esters; Germany; Glucosides; Hydrocarbons, Chlorinated; Iridoids; Molecular Structure; Nitric Oxide; Picrates; Superoxides; Veronica

The synthesis of three types of pulvinic acid analogues, using a diversity-oriented strategy starting from a single compound, dimethyl l-tartrate, is described. Lacey-Dieckmann condensation, alcohol dehydration and Suzuki-Miyaura cross-couplings were employed in the course of the analogues syntheses. The evaluation of the antioxidant properties of the 28 synthesized analogues was carried out using antioxidant capacity assays (protection of thymidine and β-carotene) and free radical scavenging assays (DPPH radical and ABTS radical cation). This allowed to assess the relative influence of the groups bonded to the tetronic ring and to the exocyclic double bond on the activity, as well as the importance of this exocyclic double bond. It was shown that the presence of an electron-donating group on the 3-position of the tetronic ring had a beneficial effect. It was shown in several assays that the presence of the exocyclic bond was not crucial to the activity.

Topics: Benzothiazoles; beta Carotene; Biphenyl Compounds; Carboxylic Acids; Free Radical Scavengers; Lactones; Picrates; Sulfonic Acids; Tartrates; Thymidine

Antioxidant and antimelanogenesis activities of protocatechuic acid (1) from Origanum vulgare (oregano) were investigated. The antioxidative capacity of 1 was confirmed from its free-radical-scavenging activities, inhibition of lipid peroxidation, and suppression of reactive oxygen species in H(2)O(2)-induced BNLCL2 cells. The inhibition by 1 of tyrosinase and DOPA oxidase activity and melanin production was possibly related to the down-regulation of melanocortin-1 receptor, microphthalmia-associated transcription factor, tyrosinase, tyrosinase-related proteins-2, and tyrosinase-related proteins-1 expression in α-melanocyte-stimulating hormone-induced B16 cells. After a gel containing 1 was applied to mice, the values of L* slightly increased, and a* and erythema-melanin levels of skin were reduced by comparing the values of untreated control groups, indicating 1 can reduce melanin production. These results suggest that 1 may act as an effective quencher of oxidative attackers with antimelanogenesis properties.

Topics: alpha-MSH; Animals; Antioxidants; Benzothiazoles; Biphenyl Compounds; Drugs, Chinese Herbal; Free Radical Scavengers; Hydroxybenzoates; Melanins; Melanocytes; Mice; Molecular Structure; Monophenol Monooxygenase; Origanum; Picrates; Reactive Oxygen Species; Skin Pigmentation; Sulfonic Acids

Forsythia suspensa extract has been proved as a potential antioxidant in the recent years. The present study was undertaken to obtain the optimal antioxidant fraction in vitro and examine its antioxidative potential against diquat-induced oxidative stress in male Sprague Dawley rats in vivo. In vitro, 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging experiment indicated that the CH2Cl2 fraction of F. suspensa (FSC) exerted the strongest scavenging activities; forsythoside A, forythialan A and phillygenin from it might be the major antioxidant constituents. In vivo, pretreatment of rats with different doses of FSC (25, 50 and 100 mg/kg bw) and vitamin C (100 mg/kg bw, positive control) for 15 days significantly lowered the tumor necrosis factor-alpha (TNF-alpha), interleukin-1beta (IL-1beta), and interleukin-6 (IL-6) in plasma compared to the negative control group. Also, FSC significantly increased the activities of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), and the levels of glutathione (GSH) in plasma, liver and kidney whereas it decreased the levels of malondialdehyde (MDA) in plasma and kidney. Moreover, the protective effect of FSC (100 mg/kg bw) was better than vitamin C. These results revealed that FSC exerted a protective effect against diquat-induced oxidative stress and is worthy of becoming a potential dietary antioxidant.

Topics: Animals; Antioxidants; Ascorbic Acid; Biphenyl Compounds; Cytokines; Diquat; Forsythia; Free Radicals; Fruit; Glycosides; Herbicides; Indicators and Reagents; Kidney; Lignans; Liver; Male; Oxidative Stress; Oxidoreductases; Picrates; Rats; Rats, Sprague-Dawley

The present research aimed at evaluating the vitamin C, total phenolic content (TPC), phenolic compounds, carotenoids, and chlorophyll contents, as well as antioxidant activity (AAC) of six Actinidia species fruit. Vitamin C, phenolic compounds, carotenoids and chlorophylls were measured using high-performance liquid chromatography. TPC was determined using the Folin-Ciocalteau reagent, and AAC using 2,2-diphenyl-1-picryl hydrazyl (DPPH) assay. The highest concentrations of vitamin C and TPC were found for Actinidia kolomikta fruit (1008.3 and 634.1 mg/100 g fresh weight [FW], respectively). Among phenolic compounds, seven phenolic acids and three flavonoids were identified. The 2,5-dihydroxybenzoic acid prevailed in A. kolomikta (425.54 mg/100 g FW), while tannic acid dominated in other species (4.63-100.43 mg/100 g FW). The largest amounts of chlorophylls and carotenoids were identified as Actinidia macrosperma (4.02 and 2.09 mg/100 g FW, respectively). The AAC of fruit extracts decreased in the order of A. kolomikta > Actinidia purpurea > Actinidia melanandra > A. macrosperma > Actinidia arguta > Actinidia deliciosa according to the DPPH assay.

Topics: Actinidia; Antioxidants; Ascorbic Acid; Biphenyl Compounds; Carotenoids; Chlorophyll; Chromatography, High Pressure Liquid; Flavonoids; Fruit; Phenols; Phylogeny; Picrates; Plant Extracts; Polyphenols; Species Specificity; Tannins

It is well known that extracts of purple sweet potato (PSP) have potent antioxidant activity. However, it has not been established whether extracts of PSP inhibit oxidation of low-density lipoprotein (LDL) or protein glycation. LDL oxidation and protein glycation are well-known risk factors for chronic metabolic diseases, such as atherosclerosis and diabetes mellitus. Chopped and sliced PSP and yellow sweet potato (YSP) were extracted individually at a concentration of 1 g of PSP tuber/mL using either ethanol or water for 6 hours. The PSP ethanol extract (100-fold diluted) showed stronger radical (2,2-diphenyl-1-picrylhydrazyl radical) scavenging activity than the water extract of PSP and the ethanol extract of YSP (up to a sixfold higher activity). The ethanol extract of PSP also exhibited the highest increase in ferric reducing ability among all extracts. Cupric ion-mediated LDL oxidation was strongly inhibited by the ethanol extract of PSP, with similar potency to vitamin C treatment (final concentration, 10 mM). The PSP extract strongly inhibited fructose-mediated protein glycation as determined by fluorescence spectroscopy. The PSP extract-treated apolipoprotein (apo) A-I showed a decreased multimerization pattern on sodium dodecyl sulfate-polyacrylamide gel electrophoresis, whereas glycated apoA-I showed the strongest multimeric band. PSP extract treatment also inhibited the uptake of oxidized LDL into human macrophage cells with suppression of malondialdehyde production in the cell culture medium. In conclusion, these results suggest that the extract of PSP can be used as a putative anti-atherosclerotic and antidiabetic agent with strong antioxidant functions. This is the first report to show the biological functions of PSP extract to treat hyperlipidemic and hyperglycemic disorders.

Topics: Antioxidants; Apolipoprotein A-I; Ascorbic Acid; Atherosclerosis; Biphenyl Compounds; Cholesterol, LDL; Fructose; Glycation End Products, Advanced; Glycosylation; Humans; Ipomoea batatas; Lipid Peroxidation; Macrophages; Malondialdehyde; Phytotherapy; Picrates; Plant Extracts; Plant Roots

Fifteen fruits commonly used by the ethnic population in Nepal were studied for the antioxidant activity and total polyphenol content (TPC). Among them, Terminalia bellirica, Terminalia chebula, Phyllanthus emblica and Spondias pinnata were the most potent antioxidants as compared with vitamin C based on the 1,1-diphenyl-2-picryl hydrazyl radical assay. These fruits also contained high TPCs. Spondias pinnata, Pyrularia edulis, Melastoma malabathricum, Cipadema bacifera and Choerospondias axillaries fruits were evaluated for the first time. Moreover, Spondias pinnata was found to be more potent (16% radical scavenging activity at 5 microg/ml) than vitamin C (5% radical scavenging activity at 5 microg/ml). Antioxidant activity showed correlation to TPC with the correlation coefficients (R(2)) as 0.7189 and 0.7246 for the methanol and water extracts, respectively. This study suggests that a number of these fruits may have the potential to confer beneficial health effects due to their antioxidant activity and TPC.

Topics: Anacardiaceae; Antioxidants; Ascorbic Acid; Biphenyl Compounds; Flavonoids; Free Radical Scavengers; Fruit; Magnoliopsida; Nepal; Phenols; Phyllanthus; Picrates; Plant Extracts; Polyphenols; Terminalia

Jujube (Ziziphus jujuba Mill.) has long been used for human consumption and medicinal purposes in China. It is recommended for some diseases in which radical species are produced as a result of oxidative stress. However, the systematic study on the antioxidant capacities of various tissues of jujube is still lacking. In order to address this, various tissues of three jujube varieties were characterized with respect to their antioxidant capacities and antioxidant compounds such as flavonoid, ascorbic acid, anthocyanin and phenolic. Antioxidant capacity was measured using the DPPH (2,2-diphenyl-1-picrylhydrazyl) and FRAP (ferric-reducing antioxidant power) assays. The phenolic acids were analyzed by high-performance liquid chromatography (HPLC). The results show that the peel of all cultivars has the highest antioxidant capacities, reflecting the highest content of total phenolics, flavonoids, and anthocyanins found in this part. In addition, the predominant phenolic acid in jujube was found to be protocatechuic acid, followed by gallic acid, chlorogenic acid and caffeic acid. The results obtained in this study clearly indicate that Chinese jujube has a significant potential to use as a natural antioxidant agent.

Topics: Anthocyanins; Antioxidants; Ascorbic Acid; Biphenyl Compounds; China; Chromatography, High Pressure Liquid; Ethanol; Picrates; Plant Extracts; Ziziphus

An analytical study was carried out on the presence of antioxidant constituents and the in vitro antioxidant capacity in the extracts of three species of Spanish red-skinned cactus pear fruits (Opuntia ficus-indica, Opuntia undulata and Opuntia stricta). The cactus pear fruit extracts were analyzed for determined constituents: ascorbic acid, flavonoids (quercetin, isorhamnetin, myricetin, kaempferol and luteolin), betalains, taurine, total carotenoids and total phenolics. The antioxidant capacity was assessed by means of two different methods: the 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) (Trolox equivalent antioxidant capacity) method and the 2,2-diphenyl-1-picrylhydrazyl radical method. Opuntia ficus-indica fruit extract had the strongest antioxidant capacity and taurine content. O. stricta fruits were the richest in ascorbic acid and total phenolics, whereas O. undulata fruits showed the highest carotenoid content. Quercetin and isorhamnetin were the main flavonoids detected. This study provides basic information on the presence of bioactive compounds and antioxidant capacity in extracts of cactus pear fruits, in order to consider these extracts as ingredient for the production of health-promoting food.

Topics: Antioxidants; Ascorbic Acid; Biphenyl Compounds; Carotenoids; Chromans; Flavonoids; Flavonols; Fruit; Opuntia; Phenols; Picrates; Plant Preparations; Polyphenols; Quercetin; Taurine

Spirulina is a commercial alga well known to contain various antioxidants, especially phycocyanin. Apart from being sold as a nutraceutical, Spirulina is incorporated as a functional ingredient in food products and beverages. Most of the previous reports on antioxidant activity of Spirulina were based on chemical rather than cell-based assays. The primary objective of this study was to assess the antioxidant activity of aqueous extract from Spirulina based on its protective effect against cell death induced by free radicals.. The antioxidant activity of the cold water extract from food-grade Spirulina platensis was assessed using both chemical and cell-based assays. In the cell-based assay, mouse fibroblast cells (3T3) cells were incubated for 1 h in medium containing aqueous extract of Spirulina or vitamin C (positive control) at 25, 125 and 250 μg/mL before the addition of 50 μM 1,1-diphenyl-2-picrylhydrazyl (DPPH) or 3-ethylbenzothiazoline-6-sulfonic acid (ABTS). The cells were incubated for another 24 h before being assessed for cell death due to apoptosis using the Cell Death Detection ELISA Kit. Spectrophotometric assays based on DPPH and ABTS were also used to assess the antioxidant activity of the extract compared to vitamin C and vitamin E (positive controls).. Spirulina extract did not cause cytotoxic effect on 3T3 cells within the range of concentrations tested (0 - 250 μg/mL). The extract reduced significantly (p < 0.05) apoptotic cell death due to DPPH and ABTS by 4 to 5-fold although the activity was less than vitamin C. Based on the DPPH assay, the radical scavenging activity of the extract was higher than phycocyanin and was at least 50% of vitamin C and vitamin E. Based on the ABTS assay, the antioxidant activity of the extract at 50 μmug/mL was as good as vitamin C and vitamin E.. The results showed that aqueous extract of Spirulina has a protective effect against apoptotic cell death due to free radicals. The potential application of incorporating Spirulina into food products and beverages to enhance their antioxidant capacity is worth exploring.

Topics: 3T3 Cells; Animals; Antioxidants; Apoptosis; Ascorbic Acid; Benzothiazoles; Biphenyl Compounds; Enzyme-Linked Immunosorbent Assay; Fibroblasts; Free Radicals; Mice; Oxidative Stress; Phycocyanin; Picrates; Plant Extracts; Spectrophotometry; Spirulina; Sulfonic Acids; Vitamin E

2-Dimethylaminomethylene-1-benzosuberone 1 was coupled with diazotized aniline derivatives to afford a series of the hitherto unreported 2-arylazo-1-benzosuberones 3a-i. The tautomeric structure and the effect of substituents on the tautomeric form (s) of the products 3a-i were discussed. Similar coupling of the enaminone 1 with diazonium salts of heterocyclic amines gave the respective fused azolotriazino-benzosuberones. Some of the newly synthesized compounds showed potent antimicrobial, anti-HCV, antioxidant, antitumor (as topoisomerase I inhibitors), and antimicrobial activities.

Topics: Animals; Anti-Bacterial Agents; Antineoplastic Agents; Antioxidants; Antiviral Agents; Azo Compounds; Biphenyl Compounds; Cricetinae; Hepacivirus; Hydrazones; Inhibitory Concentration 50; Magnetic Resonance Spectroscopy; Mass Spectrometry; Mice; Microbial Sensitivity Tests; Neoplasms, Experimental; Picrates; Spectrophotometry, Infrared; SSPE Virus

A novel antioxidant activity assay was developed using laccase-oxidized phenolics. In a three-step approach, phenolic compounds were first oxidized by laccase. Laccase was then inhibited using 80% (v/v) methanol which also stabilized the oxidized phenolics which were then used to measure antioxidant activities of ascorbic acid and Trolox. From a number of laccase-oxidized phenolics screened for potential use in the measurement of antioxidant activities, syringaldazine emerged the best, giving results comparable to the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical, which is currently used in conventional methods. Like DPPH radicals, two moles of stoichiometric oxidized syringaldazine were reduced by one mole of either ascorbic acid or Trolox. For the first time we show that antioxidant activity can be correlated to oxygen consumption by laccase. Reduction of one molecule of oxygen corresponded to oxidation of four molecules of syringaldazine which in turn is reduced by two molecules of Trolox or ascorbic acid. This study therefore demonstrates the great potential of using laccase-oxidized syringaldazine for the measurement of antioxidant activity.

Topics: Antioxidants; Ascorbic Acid; Biological Assay; Biphenyl Compounds; Chromans; Free Radicals; Laccase; Methanol; Oxidation-Reduction; Oxygen; Phenols; Picrates; Spectrophotometry, Ultraviolet; Time Factors

The influence of high O(2) atmosphere on postharvest decay, quality, total phenolic, total anthocyanin contents, antioxidant enzymes activity, and antioxidant activity of Chinese bayberry fruit was investigated. Freshly harvested Chinese bayberry fruits were placed in jars and ventilated continuously with air or with 80 and 100% O(2) for up to 12 days. Samples were randomly selected initially and at 3-days interval during storage. The fruit exposed to high O(2) was resistant to decay, had high levels of total soluble solids, titratable acidity and ascorbic acid contents, and also reduced the increment of pH value. High O(2) treatment was less stressful as reflected by having the significantly lower malonaldehyde contents and higher catalase, ascorbic acid peroxidase, and peroxidase activities during storage. Both 80% and 100% O(2) treaments had also retained the bioactive contents and 1,1-diphenyl-2-picrylhydrazyl radical scavenging activity during storage. These results indicate that elevated O(2) levels may improve the ability of the antioxidative defense mechanism in Chinese bayberry and result in a better control of fruit decay.

Topics: Anthocyanins; Antioxidants; Ascorbic Acid; Biphenyl Compounds; Catalase; Food Preservation; Free Radical Scavengers; Fruit; Malondialdehyde; Myrica; Oxygen; Peroxidase; Picrates

Three new compounds were isolated from the stems of Dendrobium candidum: (S)-3,4,4'-trihydroxy-5,alpha-dimethoxybibenzyl (1), named dendrocandin C; (S)-3,4,4'-trihydroxy-5-methoxy-alpha-ethoxybibenzyl (2), named dendrocandin D; and 3,3',4,4'-tetrahydroxy-5-methoxybibenzyl (3), named dendrocandin E. Their structures were elucidated by 1D- and 2D-NMR spectroscopy and mass spectroscopy. The isolated compounds exhibited potent antioxidant activity in the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging test, with IC(50) values of 34.2, 34.5, and 15.6 microM for compounds 1, 2, and 3, respectively. Vitamin C was used as positive control with IC(50) 23.2 microM.

Topics: Antioxidants; Ascorbic Acid; Bibenzyls; Biphenyl Compounds; Dendrobium; Magnetic Resonance Spectroscopy; Methanol; Picrates; Solvents; Spectrometry, Mass, Electrospray Ionization; Spectrophotometry, Ultraviolet

Powdered rooibos tea extract (RTE), which is rich in polyphenols, is made from rooibos tea by freeze-drying. "Rooibos" is Afrikaans for "red bush," and the scientific name is "Aspalathus linearis." It is a broom-like member of the legume family of plants and is used to make an herbal tea which has been popular in South Africa for generations and is now consumed in many countries. In the present work, the anti-oxidative effect of RTE on oils and fats in autoxidation or thermal oxidation was studied, and it was confirmed that RTE has a very strong anti-oxidative effect on emulsifying oils owing to the water-soluble polyphenols such as rutin and quercetin contained in RTE. RTE was found to have a strong ability to quench radicals generated in the water phase, and to confer higher thermal stability against deep fat frying than tocopherol. But RTE showed little anti-oxidative effect on frying oil because of its lower oil-solubility.

Topics: Antioxidants; Ascorbic Acid; Aspalathus; Biphenyl Compounds; Citric Acid; Esters; Flavonoids; Free Radical Scavengers; Linoleic Acid; Lipid Metabolism; Oxidation-Reduction; Peroxides; Phenols; Phosphatidylethanolamines; Picrates; Plant Extracts; Polyphenols; Safflower Oil; Soybean Oil; Tea; Temperature; Time Factors

An antioxidant substance (AOS) obtained from an enzymatic extract of the red seaweed Gloiopeltis tenax was purified by DEAE-Sephadex CL-6B and Sephadex G-100 column chromatography. The purification yield of AOS was 14.3%. The AOS predominantly contained fucose, mannose, and galactose but also contained a sulfate group. The structure of AOS was investigated by periodate oxidation, desulfation, Fourier transform-infrared spectroscopy, and nuclear magnetic resonance spectroscopy. AOS was mainly composed of alternating units of beta-D-Glc(1 --> 2)alpha-D-Man(1 --> 4)beta-D-Gal(1 --> 4)alpha-D-Man(1 --> 4)beta-D-Gal alpha-D-Man (1 --> 4) beta-D-Glc (or Xyl)- and branched linkage of alpha-D-Man(1 --> 3) alpha-D-Fuc. In addition, the fucose residues were shown to be 2-O- and 4-O-sulfated and, therefore, were either terminal or 3-linked. The antioxidative activity of AOS was measured using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging assay and the beta-carotene-linoleate assay systems and was compared with those of butylated hydroxytoluene and ascorbic acid (AscA). The results showed that AOS exhibited higher antioxidative activity than AscA in the DPPH assay model and in the beta-carotene-linoleate assay system at all of the four concentration levels tested (from 50 to 200 microg/mL). These results suggested that AOS from the red seaweed G. tenax is an efficient novel antioxidant.

Topics: Antioxidants; Ascorbic Acid; Biphenyl Compounds; Butylated Hydroxytoluene; Free Radical Scavengers; Hexoses; Picrates; Plant Extracts; Seaweed; Sulfates

Russula delica Fr. is a well known macrofungi which is used as a food in Turkey. The ethanolic extract of R. delica exhibited antimicrobial activity against some of the tested foodborne and spoilage bacteria. The phenolic composition of R. delica ethanolic extract was analyzed by high performance liquid chromatography (HPLC). The major component in R. delica ethanolic extract was catechin (5.33 mg/L). Antioxidant activities of the ethanolic extract of R. delica was evaluated by using 2,2-diphenyl-1-picrylhydrazyl (DPPH) radicals scavenging and chelating ability on ferrous ions assays. Scavenging effect on DPPH radicals was 26% at 10mg/ml and chelating effects on ferrous ions was 58% at 5mg/ml. In addition, the amounts of total phenol content (6.23 mg/g), ascorbic acid (2.93 mg/g), beta-carotene (0.11 mg/g) and lycopene (0.03 mg/g) in the macrofungi ethanolic extract were determined.

Topics: Agaricales; Anti-Infective Agents; Antioxidants; Ascorbic Acid; beta Carotene; Biphenyl Compounds; Carotenoids; Catechin; Chromatography, High Pressure Liquid; Ethanol; Free Radical Scavengers; Free Radicals; Indicators and Reagents; Iron Chelating Agents; Lycopene; Microbial Sensitivity Tests; Phenols; Picrates; Plant Extracts; Solvents

Nine new gentisyl alcohol derivatives, namely, the trimeric terrestrol A (8), dimeric terrestrols B-H (1-7), and a monomeric derivative (12), together with four known analogues (9-11, 13) were isolated from the marine-derived fungus Penicillium terrestre. The structures of the new compounds were elucidated by spectroscopic methods including one- and two-dimensional NMR as well as low- and high-resolution mass spectrometric analysis. These new compounds (1-8, 12) showed cytotoxic effects on HL-60, MOLT-4, BEL-7402, and A-549 cell lines with IC50 values in the range 5-65 microM. Compound 6 also showed moderate inhibitory activity against protein tyrosine kinases (Src and KDR). Furthermore, all new compounds exhibited moderate radical scavenging activity against DPPH with IC50 values in the range 2.6-8.5 microM.

Topics: Antineoplastic Agents; Benzyl Alcohols; Biphenyl Compounds; China; Drug Screening Assays, Antitumor; Free Radical Scavengers; Humans; Inhibitory Concentration 50; Marine Biology; Molecular Structure; Penicillium; Picrates; src-Family Kinases; Vascular Endothelial Growth Factor Receptor-2

The structure of an antiradical arabinoglucogalactan ( 1) from Panax notoginseng roots was determined. This polymeric carbohydrate was obtained through successive phosphate buffer (pH 7.0) extraction after cold-water pretreatment and purification by ion-exchange and gel-filtration chromatography. Monosaccharide analysis, permethylation analysis, NaIO 4 and CrO 3 oxidations, Smith degradation, graded acid hydrolysis, and IR and NMR experiments indicated that 1 possesses a backbone of (1-->3)-linked beta- d-galactofuranosyl residues, with branches of alpha- l-Ara f-(1-->4)-beta- d-Glc p-(1--> residues at O-6. Additionally, 1 exhibited high scavenging activity against DPPH free radicals with a 50% scavenging concentration (SC50) of 11.72 +/- 0.91 microg/mL, suggesting that this arabinoglucogalactan is a potential antiradical.

Topics: Biphenyl Compounds; Carbohydrate Sequence; Free Radical Scavengers; Galactans; Nuclear Magnetic Resonance, Biomolecular; Oxidation-Reduction; Panax notoginseng; Picrates; Plant Roots; Plants, Medicinal; Stereoisomerism

In order to search for structurally novel and bioactive natural compounds from microorganisms, a halotolerant fungal strain, Penicillium citrinum B-57, which mainly produces citrinin derivatives, was isolated from sediments collected from the Jilantai salt field. From the ethyl acetate extract of P. citrinum B-57, two new citrinin dimers, pennicitrinone C ( 1) and penicitrinol B ( 2), and 11 known related compounds were isolated and identified by spectroscopic and chemical methods. These compounds showed antioxidative activity against DPPH radicals with IC 50 values ranging from 0.8 to 59 microM.

Topics: Antioxidants; Biphenyl Compounds; China; Citrinin; Molecular Structure; Penicillium; Picrates

Chemical analysis of the fruiting bodies of the agaricoid fungus Cortinarius subtortus yielded three new natural products, two quinoline and one isocarbostyryl alkaloid. The structures of compounds 1- 3 were determined by analysis of NMR and MS data. Compound 1 exhibited inhibitory effects against the phytopathogenic fungus Colletotrichum coccodes. All three compounds displayed moderate antioxidant activity in a DPPH free radical scavenging bioassay.

Topics: Agaricales; Alkaloids; Antifungal Agents; Antioxidants; Biphenyl Compounds; Colletotrichum; Free Radical Scavengers; Fruiting Bodies, Fungal; Germany; Isoquinolines; Molecular Structure; Nuclear Magnetic Resonance, Biomolecular; Picrates

A new cysteine sulfoxide, (S(S)R(C))-S-(3-pentenyl)-L-cysteine sulfoxide (1), was identified from the seeds of Allium cepa var. tropeana, together with the known methiin, etiin, alliin, isoalliin, propiin, and butiin. The structure of compound 1 was established by analysis of its physical and spectroscopic data. The antioxidant activity of an extract containing cysteine sulfoxides and compound 1 was evaluated using the FRAP and DPPH tests.

Topics: Antioxidants; Biphenyl Compounds; Cysteine; Italy; Molecular Structure; Nuclear Magnetic Resonance, Biomolecular; Onions; Picrates; Seeds; Sulfoxides

Argpyrimidine, the product of non-enzymatic protein glycation by methylglyoxal, has been implicated in the pathophysiology of diabetes mellitus and neurodegenerative diseases. Chemically, argpyrimidine is a substituted pyrimidinol with structural features common to known antioxidants. The objective of this study was to investigate the antioxidant properties of argpyrimidine. Argpyrimidine was synthesized by mixing L-arginine with 3-acetoxypentane-2,4-dione under acidic conditions and purified by chromatography. Argpyrimidine inhibited lipid peroxidation of rat brain homogenates catalyzed by hydroxyl radicals, metal ions, and autooxidation in a concentration- and time-dependent manner. In addition, argpyrimidine scavenged superoxide anion, 1,1-diphenyl 2-picryl-hydrazyl-stable free radical, intracellular-hydrogen peroxide, and inhibited free-radical-mediated nicking of plasmid-DNA. Taken together, our data suggest that argpyrimidine has antioxidant properties and may therefore have biological relevance in pathophysiologies associated with diabetes mellitus and neurodegenerative diseases.

Topics: Antioxidants; Ascorbic Acid; Biphenyl Compounds; Cell Line, Tumor; DNA; Ferric Compounds; Ferrous Compounds; Free Radical Scavengers; Humans; Hydrogen Peroxide; In Situ Nick-End Labeling; Lipid Peroxidation; Ornithine; Oxidants; Oxidation-Reduction; Oxidative Stress; Picrates; Plasmids; Pyrimidines; Superoxides

4-Amino-5-phenyl-4H-1,2,4-triazole-3-thiol (1) underwent facile condensation with various phosphorus dichlorides (2a-j) in the presence of triethylamine in dry tetrahydrofuran at 60-65 degrees C and afforded corresponding thiadiazaphosphol-2-ones (3a-j). Their chemical structures were characterized using IR, (1)H-, (13)C-, (31)P-NMR and Mass spectral studies. All the title compounds were screened for antioxidant properties by radical scavenging methods such as 1,1-diphenyl-2-picryl hydrazyl (DPPH), hydroxyl and lipid peroxidation. They exhibited potent in vitro antioxidant activity dose dependently. Their bioassay showed them to possess significant antibacterial activity.

Topics: Anti-Bacterial Agents; Antioxidants; Ascorbic Acid; Bacteria; Biphenyl Compounds; Ferric Compounds; Free Radical Scavengers; Hydroxyl Radical; Lipid Peroxidation; Magnetic Resonance Spectroscopy; Mass Spectrometry; Microbial Sensitivity Tests; Organophosphorus Compounds; Picrates; Spectrophotometry, Infrared; Thiadiazoles

Recent investigations have shown that the antioxidant properties of plants could be correlated with oxidative stress defense and different human diseases. In this respect flavonoids and other polyphenolic compounds have gained the greatest attention. The present study was undertaken to evaluate the in vitro and in vivo antioxidant activities of aqueous extract of Artemisia vulgaris. The plant extract was tested for DPPH (2, 2-diphenyl, 2-picryl hydrazyl) radical scavenging, nitric oxide radical scavenging, reducing power assays, total phenol, flavonoid and flavonol content. Determination of serum ascorbic acid level, blood glutathione level and superoxide dismutase activity in rats treated with 100 mg/Kg of Artemisia vulgaris extract. The extract exhibited scavenging potential with IC50 value of 11.4 micro g/ ml for DPPH, the value were found to close to those of standard rutin (10 micro g/ ml).On the other hand Artemisia vulgaris extract exhibited nitric oxide scavenging activity with IC50 value 125 mg/ ml. The reducing power of the extract depends on the amount of extract. The content of phenolic compounds (mg/g) in aqueous extract was found 19 +/- 0.16 mg/g plant extract and expressed in gallic acid equivalents (GAE). The flavonoidal and flavonol contents were found to be 7.96 +/- 0.76 and 3.4 +/- 0.0 respectively mg/g plant extract in rutin equivalent. The treatment of rats with aqueous extract of Artemisia vulgaris resulted in a significant increase in blood glutathione level, superoxide dismutase activity and serum ascorbic acid level as compared to their corresponding controls. The results obtained in the present study indicate that aqueous extract of Artemisia vulgaris is a potential source of natural antioxidants.

Topics: Administration, Oral; Animals; Artemisia; Ascorbic Acid; Biphenyl Compounds; Flavonoids; Flavonols; Free Radical Scavengers; Glutathione; Male; Nitric Oxide; Oxidation-Reduction; Phenols; Picrates; Plant Extracts; Rats; Rats, Wistar; Superoxide Dismutase

A novel norlignan derivative, crassifogenin C (1), and a known compound, curcapital (2), were isolated from the ethanolic extract of the rhizomes of Curculigo crassifolia. Their structures were elucidated on the basis of spectroscopic evidence and comparisons with literature data. Curcapital (2) was isolated from this plant for the first time. The free radical scavenging activity of the isolated compounds along with crassifoside E (3) and crassifoside F (4), which were reported previously, was evaluated by the 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay. All compounds showed strong radical scavenging activity. The primary structure-activity relationship is also discussed.

Topics: Ascorbic Acid; Biphenyl Compounds; Curculigo; Free Radical Scavengers; Lignans; Magnetic Resonance Spectroscopy; Molecular Conformation; Picrates; Plant Roots; Spectrophotometry, Infrared; Spectrophotometry, Ultraviolet

Danshensu (3-(3,4-dihydroxyphenyl) lactic acid) and salvianolic acid B, two natural phenolic acids of caffeic acid derivatives isolated from Salvia miltiorrhiza root of the most widely used traditional Chinese medicine for the treatment of various cardiovascular diseases, have been reported to have potential protective effects from oxidative injury. To better understand their biological functions, the in vitro radical scavenging and antioxidant activities of danshensu and salvianolic acid B were evaluated along with vitamin C. Both danshensu and salvianolic acid B exhibited higher scavenging activities against free hydroxyl radicals (HO()), superoxide anion radicals (O(2)(-)), 1,1-diphenyl-2-picryl-hydrazyl (DPPH) radicals and 2-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) radicals than vitamin C. In contrary, danshensu and salvianolic acid B showed weaker iron chelating and hydrogen peroxide (H(2)O(2)) scavenging activities than vitamin C. As expressed as vitamin C equivalent capacity (VCEAC), the relative VCEAC values (mg/100ml) were in the order of salvianolic acid B (18.59) > danshensu (12.89) > vitamin C (10.00) by ABTS radical assay. The protective efficiencies against hydrogen peroxide induced human vein vascular endothelial cell damage were correlated with their antioxidant activities. Analysis of structure-activity relationship of these two compounds showed that the condensation and conjugation of danshensu and caffeic acid appears important for antioxidant activity. These results indicated that danshensu and salvianolic acid B are efficient radical scavengers and antioxidants, and salvianolic acid B is superior to danshensu. Their radical scavenging and antioxidant properties might have potential applications in food and healthcare industry.

Topics: Antioxidants; Ascorbic Acid; Benzofurans; Benzothiazoles; Biphenyl Compounds; Cell Survival; Chelating Agents; Endothelial Cells; Ferrous Compounds; Free Radical Scavengers; Humans; Hydrogen Peroxide; Hydroxyl Radical; Lactates; Oxidants; Picrates; Plant Roots; Salvia; Sulfonic Acids; Tetrazolium Salts; Thiazoles

Eleven antidiabetic traditional Chinese medicine (TCM) extracts rich in saponins were examined for their antioxidant and antiglycation activities. The antioxidant activities of these extracts were evaluated by studying the inhibition of lipid peroxidation in rat liver microsomes induced by ascorbate/Fe2+, cumine hydroperoxide (CHP) or CCl4/reduced form of nicotinamide-adenine dinucleotide phosphate (NADPH). The antioxidant capacities were also evaluated by studying the scavenging of 2,2'-diphenyl-1-picrylhydrazyl (DPPH) free radical. The antiglycation activities of these extracts were evaluated by hemoglobin-delta-gluconolactone (delta-Glu) assay, bovine serum albumin (BSA)-glucose assay and N-acetyl-glycyl-lysine methyl ester (GK peptide)-ribose assay. Aralia taibaiensis outperformed other extracts in most of the assays except inhibition of early glycation products formation, where Acanthopanax senticosus showed higher activity. Aralia taibaiensis was particularly potent in inhibiting the late glycation and formation of advanced glycation end products (AGEs) on proteins. The antioxidant and antiglycation activities of most extracts were correlated with the saponin content. The results demonstrate that the antidiabetic activities of most extracts could be explained, at least in part, by their combined antioxidant and antiglycation properties.

Topics: Animals; Antioxidants; Ascorbic Acid; Biphenyl Compounds; Diabetes Mellitus; Drugs, Chinese Herbal; Free Radical Scavengers; Hydrazines; Lipid Peroxidation; Microsomes, Liver; Nitrosamines; Oxidation-Reduction; Picrates; Rats; Rats, Sprague-Dawley; Saponins

Numerous investigations exist about the alterations that oxygen free radicals can provoke on biomolecules; these modifications can be prevented and/or reversed by different antioxidants agents. On the other hand, 2,2-diphenyl-1-picrylhydrazyl radical (DPPH), a stable nitrogen synthetic radical, is used to evaluate the antioxidant capacity of medicinal herbal products; however, the structural changes that this radical provoke on the herbal active principles are not clear yet. In this work, we compared the redox reactivity of oxygen free radicals and DPPH radical on phospholipids and protein thiol groups present in rat liver microsomes. Cu2+/ascorbate was used as generator system of oxygen free radical and as antioxidant, an extract of Buddleja globosa's leaves. Cu2+/ascorbate provoked microsomal lipid peroxidation, microsomal thiols oxidation and oxygen consumption; all of these phenomena were inhibited by B. globosa extract. On the other hand, DPPH was bleached in different extension by the herbal extract and phosphatidyl choline; beside, DPPH decreased microsomal thiols content, but this phenomenon were not prevented by the herbal extract. Furthermore, DPPH did not induce oxygen consumption and neither modified the oxygen consumption induced by Cu2+/ascorbate. Distinct redox mechanisms may explain the differences between the reactivity of DPPH and oxygen free radicals on biomolecules, which is discussed.

Topics: Animals; Antioxidants; Ascorbic Acid; Biphenyl Compounds; Buddleja; Copper; Flavonoids; In Vitro Techniques; Indicators and Reagents; Lipid Peroxidation; Male; Microsomes, Liver; Oxidants; Oxidation-Reduction; Oxygen Consumption; Phenols; Phosphatidylcholines; Picrates; Plant Extracts; Polyphenols; Rats; Rats, Sprague-Dawley; Reactive Oxygen Species; Sulfhydryl Compounds

The glycation reaction involves a series of non-enzymatic reactions between the carbonyl group on reducing sugars and the amino group on proteins leading to the formation of advanced glycation end-products (AGEs), which are acknowledged to be involved in the pathogenesis of diabetic and aging-related complications. Consequently, the development of AGE inhibitors is considered to have therapeutic potential in patients with diabetes or age-related diseases. The preliminary results showed that a methanol extract (PAE) of Plantago asiatica, which is traditionally used as a folk medicine in Asian countries to treat fever, cough, wound etc., had strong glycation inhibitory activity. The effects of the extract on AGE fluorescence were dose-dependent, reaching 41% inhibition at 0.1 microg/mL of extract. The purified principle from PAE was identified as plantamajoside. As well as antioxidant activities, in vitro glycation inhibitory activities with 10 and 25 mm plantamajoside were higher than those with 10 and 25 mm aminoguanidine. The results demonstrate that PAE and plantamajoside had significant effects on in vitro AGE formation, and the glycation inhibitory activity and antioxidant activity of plantamajoside were comparable to those obtained using millimolar concentrations of the standard antiglycation agent aminoguanidine, and the antioxidant ascorbate, respectively.

Topics: Antioxidants; Ascorbic Acid; Biphenyl Compounds; Catechols; Dose-Response Relationship, Drug; Enzyme Inhibitors; Flavonoids; Glucosides; Glycation End Products, Advanced; Guanidines; Magnetic Resonance Spectroscopy; Methanol; Phenols; Picrates; Plant Extracts; Plantago; Polyphenols

Many studies have focused on the effect of fresh fruits on the risk of developing cancer and other diseases involved with reactive species and free radicals. The intake of frozen fruits has spread widely in the last years, but, until now, their biological activity is not completely known. In this study, 23 samples of frozen fruits were analyzed for their nutritional composition, total polyphenols, total carotenoids, and vitamin C content. Antioxidant, mutagenic, and antimutagenic effects were also evaluated. Antioxidant assays included 2,2-diphenyl-1-picrylhydrazyl radical (DPPH(.)) scavenging activity and determination of superoxide dismutase (SOD)- and catalase (CAT)-like activities. Mutagenic and antimutagenic evaluations were performed in eukaryotic cells of Saccharomyces cerevisiae yeast. Most samples (74%) showed antioxidant activity similar to vitamin C in the DPPH(.) assay, and this activity was positively correlated (r = 0.366; P

Topics: Antimutagenic Agents; Antioxidants; Ascorbic Acid; Biphenyl Compounds; Carotenoids; Catalase; Flavonoids; Food Handling; Freezing; Fruit; Mutagenicity Tests; Mutagens; Pesticides; Phenols; Picrates; Polyphenols; Saccharomyces cerevisiae; Superoxide Dismutase

Two new dibenzoxazepinones have been isolated from the leaves of Carex distachya, an herbaceous plant growing in the Mediterranean area. The structures have been elucidated on the basis of their spectroscopic properties. Bidimensional NMR (DQ-COSY, TOCSY, NOESY, ROESY, HSQC, and HMBC) furnished important data useful for the characterization of the molecules. The compounds have been assayed, for the antioxidant activity, by measuring its capacity to scavenge the DPPH, the superoxide anion, and nitric oxide radicals.

Topics: Biphenyl Compounds; Carex Plant; Dibenzoxazepines; Free Radical Scavengers; Magnetic Resonance Spectroscopy; Nitric Oxide; Nitroblue Tetrazolium; Nitroprusside; Picrates; Plant Extracts; Plant Leaves; Spectrometry, Mass, Electrospray Ionization; Spectrophotometry, Infrared; Spectrophotometry, Ultraviolet; Superoxides

Bioassay-guided fractionation of the 60% ethanol extract of the stems of Dendrobium nobile using the DPPH assay led to the isolation of two new bibenzyl derivatives, nobilin D (1) and nobilin E (2), and a new fluorenone, nobilone (3), together with seven known compounds (4-10). Their structures were determined on the basis of spectroscopic analyses. Compounds 1, 2, 4, 7, 8, and 10 exhibited significant antioxidant activity higher than or equivalent to vitamin C in the DPPH assay, and compounds 1, 3, 4, and 7-10 displayed higher antioxidant activity than vitamin C in the ORAC assay. Compounds 1, 2, and 10 also exhibited stronger inhibitory effects on NO production than resveratrol.

Topics: Antioxidants; Bibenzyls; Biphenyl Compounds; Dendrobium; Drugs, Chinese Herbal; Fluorenes; Nitric Oxide; Picrates; Plant Stems; Plants, Medicinal; Resveratrol; Sesquiterpenes, Germacrane; Stilbenes

The chemistry of the burrowing sponge Aka coralliphagum was investigated to identify chemically labile secondary metabolites. The HPLC-MS analysis of the two growth forms typica and incrustans revealed different metabolites. The previously unknown sulfated compounds siphonodictyals B1 to B3 (6-8), corallidictyals C (9) and D (10), and siphonodictyal G (11) were isolated, and their structures were elucidated by NMR and MS experiments. The compounds were tested in a DPPH assay, in antimicrobial assays against bacteria, yeasts, and fungi, and in antiproliferation assays using cultures of mouse fibroblasts. The biological activity was linked to the presence of the ortho-hydroquinone moiety.

Topics: Animals; Aspergillus fumigatus; Biphenyl Compounds; Caribbean Region; Chromatography, High Pressure Liquid; Drug Screening Assays, Antitumor; Escherichia coli; Fibroblasts; Mice; Microbial Sensitivity Tests; Molecular Structure; Nuclear Magnetic Resonance, Biomolecular; Picrates; Porifera; Sesquiterpenes; Staphylococcus aureus

Eight new oxygenated lignans, kadsuphilols A-H (1-8), were isolated from the leaves and stems of Kadsura philippinensis. Four of the isolated lignans (1-4) possess the normal C18-dibenzocyclooctadiene skeleton, while the other four lignans (5-8) are C19-homolignans possessing a substituted cyclohexadienone ring with a spiro-benzofuranoid moiety. The structures of the isolated metabolites were elucidated through spectroscopic analyses, including 2D NMR experiments. Compounds 1 and 4 are the first report of an R-biphenyl configuration with a beta-oxygenated substituent at the C-9 position. The in vitro radical-scavenging activities of these compounds using DPPH were tested and evaluated. Compound 3 exhibited more potent activity than vitamins C and E.

Topics: Ascorbic Acid; Biphenyl Compounds; Free Radical Scavengers; Kadsura; Lignans; Molecular Structure; Picrates; Plant Leaves; Plant Stems; Plants, Medicinal; Taiwan; Vitamin E

Twelve new compounds, variecolorins A-L ( 1- 12), together with eleven known analogues ( 13- 23) were isolated from the broth of a halotolerant fungus, Aspergillus variecolor. The structures of compounds 1- 12 were determined by chemical and spectroscopic methods. Compounds 1- 11, 13- 15, and 20- 23 exhibited weak radical scavenging activity against DPPH, with IC 50 values from 43 to 103 microM. The new compounds 1- 12 all were essentially nontoxic against the P388, HL-60, BEL-7402, and A-549 cell lines with IC 50 values from 70 to 260 microM.

Topics: Alkaloids; Animals; Aspergillus; Biphenyl Compounds; China; Drug Screening Assays, Antitumor; Free Radical Scavengers; Inhibitory Concentration 50; Molecular Structure; Picrates; Salinity

The 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical-scavenging mechanism of 2-O-alpha-D-glucopyranosyl-L-ascorbic acid (AA-2G) was studied. We found two undefined products, named X and Y, in the reaction mixture of AA-2G and the DPPH radical under acidic conditions by HPLC analysis. The reaction mixture was further subjected to LC-MS analysis. X was found to be a covalent adduct of AA-2G and the DPPH radical. On the other hand, Y could not be identified, probably because it was a mixture. A time-course study of the radical-scavenging reaction revealed that one molecule of AA-2G scavenged one molecule of DPPH radical to generate an AA-2G radical, which readily reacted with another molecule of the DPPH radical to form a covalent adduct (X). Subsequently, this adduct slowly quenched a third molecule of the DPPH radical, resulting in reaction products (Y). Therefore, one molecule of AA-2G has only one oxidizable -OH group, but can scavenge three molecules of the DPPH radical. The radical-scavenging mechanism of AA-2G elucidated in this study should be useful in understanding the biological roles of AA-2G per se in the food and cosmetic fields.

Topics: Ascorbic Acid; Biphenyl Compounds; Chromatography, High Pressure Liquid; Free Radical Scavengers; Picrates

Lotus rhizome powder was extracted with solvents of different polarities. Antioxidant activities of the extracts were evaluated by a 2, 2'-diphenylpicrylhydrazyl (DPPH) assay and a beta-carotene bleaching assay, and compared with that of butylated hydroxyanisole (BHA) and ascorbic acid. Methanol showed the highest extract yield among all of solvents. Although acetone extract had the highest total phenolics content, methanol extract had the highest total phenolics recovery from lotus powder (20.1 mg catechin equivalents/100g lotus powder). Extract of either methanol or acetone demonstrated the highest DPPH scavenging activity at both 66.7 mg/L and 133.3 mg/L. All extracts exhibited higher antioxidant activity coefficient (AAC) than that of ascorbic acid, furthermore, dichloromethane and petroleum extracts had comparable AAC with BHA by the beta-carotene bleaching assay. The properties of the extracting solvents significantly affected the yield, total phenolics content and antioxidant activity of lotus rhizome extracts.

Topics: Acetates; Acetone; Antioxidants; Ascorbic Acid; beta Carotene; Biphenyl Compounds; Butylated Hydroxyanisole; Free Radical Scavengers; Hydrazines; Nelumbo; Picrates; Plant Extracts; Rhizome; Solvents

The effects of fruiting body maturity on antioxidant activity and antioxidants production of the wild mushroom, Lactarius piperatus, were evaluated. Several biochemical assays were used to screen the antioxidant properties: reducing power, 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging capacity, inhibition of erythrocytes hemolysis mediated by peroxyl radicals and inhibition of lipid peroxidation using the beta-carotene linoleate model system. The amounts of phenols, flavonoids, ascorbic acid, beta-carotene and lycopene present in the immature, mature and degraded fruiting bodies were also determined. The highest antioxidant contents and the lowest EC(50) values for antioxidant activity were obtained in the mature stage with immature spores.

Topics: Antioxidants; Ascorbic Acid; Basidiomycota; beta Carotene; Biphenyl Compounds; Carotenoids; Dose-Response Relationship, Drug; Erythrocytes; Flavonoids; Food Analysis; Free Radical Scavengers; Hydrazines; Lipid Peroxidation; Lycopene; Oxidation-Reduction; Phenols; Picrates; Spores, Fungal

Arsenic is one of the ubiquitous environmental pollutants, which affects nearly all organ systems. The present study has been carried out to investigate the hepatoprotective role of arjunolic acid, a triterpenoid saponin, against arsenic-induced oxidative damages in murine livers. Administration of sodium arsenite at a dose of 10 mg/kg body weight for 2 days significantly reduced the activities of antioxidant enzymes, superoxide dismutase, catalase, glutathione S-transferase, glutathione reductase and glutathione peroxidase as well as depleted the level of reduced glutathione and total thiols. In addition, sodium arsenite also increased the activities of serum marker enzymes, alanine transaminase and alkaline phosphatase, enhanced DNA fragmentation, protein carbonyl content, lipid peroxidation end-products and the level of oxidized glutathione. Studies with arjunolic acid show that in vitro it possesses free radical-scavenging and in vivo antioxidant activities. Treatment with arjunolic acid at a dose of 20 mg/kg body weight for 4 days prior to arsenic administration prevents the alterations of the activities of all antioxidant indices and levels of the other parameters studied. Histological studies revealed less centrilobular necrosis in the liver treated with arjunolic acid prior to arsenic intoxication compared to the liver treated with the toxin alone. Effects of a known antioxidant, vitamin C, have been included in the study as a positive control. In conclusion, the results suggest that arjunolic acid possesses the ability to attenuate arsenic-induced oxidative stress in murine liver probably via its antioxidant activity.

Topics: Animals; Antioxidants; Arsenic Poisoning; Ascorbic Acid; Biphenyl Compounds; Chemical and Drug Induced Liver Injury; DNA Fragmentation; Free Radical Scavengers; Glutathione; Lipid Peroxidation; Liver; Liver Function Tests; Male; Mice; Picrates; Terminalia; Triterpenes

As part of our program to develop potential imaging agents for ascorbate bioactivity in the brain, 5-O-(4'-iodobenzyl)-L-ascorbic acid was prepared through a seven-step sequence which involved C5-O-alkylation with p-iodobenzyl bromide in the presence of Ag2O and CaSO4 as the key step, starting from L-ascorbic acid. The scavenging activity of the p-iodobenzylated analog against 2,2-diphenyl-1-picrylhyrazyl (DPPH) radical was almost the same as that of L-ascorbic acid itself.

Topics: Alkylation; Ascorbic Acid; Biphenyl Compounds; Diagnostic Imaging; Free Radical Scavengers; Indicators and Reagents; Magnetic Resonance Spectroscopy; Picrates; Spectrometry, Mass, Electrospray Ionization; Spectrometry, Mass, Fast Atom Bombardment; Spectrophotometry, Infrared

Four new C18 dibenzocyclooctadiene lignans, kadsuphilins A (1) and B (3), 6-epi-gomisin (2), and 1-demethylkadsuphilin A (4), along with eight known related metabolites, were isolated from an EtOAc fraction of an alcoholic extract of the aerial parts of Kadsura philippinensis growing in Taiwan. The structures of 1-4 were elucidated on the basis of spectroscopic analyses, including 2D NMR (HMQC, HMBC, and NOESY) experiments, and by comparison of their spectroscopic data with those of related metabolites. The configurations of the biphenyl and cyclooctadiene moieties were deduced from circular dichroism (CD) and NOESY NMR spectra, respectively. Some of the compounds showed radical-scavenging activity in a DPPH-HPLC method.

Topics: Biphenyl Compounds; Cyclooctanes; Free Radical Scavengers; Kadsura; Lignans; Molecular Structure; Nuclear Magnetic Resonance, Biomolecular; Picrates; Plants, Medicinal; Taiwan

Most pomegranate (Punica granatum Linn., Punicaceae) fruit parts are known to possess enormous antioxidant activity. The present study evaluated antioxidant and hepatoprotective activity of pomegranate flowers. Alcoholic (ethanolic) extract of flowers was prepared and used in the present study. The extract was found to contain a large amount of polyphenols and exhibit enormous reducing ability, both indicative of potent antioxidant ability. The extract showed 81.6% antioxidant activity in DPPH model system. The ability of extract to scavenge reactive oxygen species (ROS) and reactive nitrogen species (RNS) was tested and it was found to significantly scavenge superoxide (O(2)(.-)) (by up to 53.3%), hydrogen peroxide (H(2)O(2)) (by up to 30%), hydroxyl radicals (()OH) (by up to 37%) and nitric oxide (NO) (by up to 74.5%). The extract also inhibited (.)OH induced oxidation of lipids and proteins in vitro. These results indicated pomegranate flower extract to exert a significant antioxidant activity in vitro. The efficacy of extract was tested in vivo and it was found to exhibit a potent protective activity in acute oxidative tissue injury animal model: ferric nitrilotriacetate (Fe-NTA) induced hepatotoxicity in mice. Intraperitoneal administration of 9 mg/kg body wt. Fe-NTA to mice induced oxidative stress and liver injury. Pretreatment with pomegranate flower extract at a dose regimen of 50-150 mg/kg body wt. for a week significantly and dose dependently protected against Fe-NTA induced oxidative stress as well as hepatic injury. The extract afforded up to 60% protection against hepatic lipid peroxidation and preserved glutathione (GSH) levels and activities of antioxidant enzymes viz., catalase (CAT), glutathione peroxidase (GPX) glutathione reductase (GR) and glutathione-S-transferase (GST) by up to 36%, 28.5%, 28.7%, 40.2% and 42.5% respectively. A protection against Fe-NTA induced liver injury was apparent as inhibition in the modulation of liver markers viz., aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP), bilirubin and albumin in serum. The histopathological changes produced by Fe-NTA, such as ballooning degeneration, fatty changes, necrosis were also alleviated by the extract. These results indicate pomegranate flowers to possess potent antioxidant and hepatoprotective property, the former being probably responsible for the latter.

Topics: Animals; Antioxidants; Ascorbic Acid; Biphenyl Compounds; Catalase; Chemical and Drug Induced Liver Injury; Ferric Compounds; Flowers; Free Radical Scavengers; Glutathione; Glutathione Peroxidase; Glutathione Transferase; Hydrogen Peroxide; Hydroxyl Radical; Lipid Peroxidation; Liver; Liver Function Tests; Lythraceae; Male; Mice; Nitric Oxide; Nitrilotriacetic Acid; Oxidants; Oxidation-Reduction; Oxidoreductases; Phenols; Picrates; Plant Extracts; Subcellular Fractions; Superoxides

In the last decade, naturally occurring antioxidants continue to play an important role in the food-supplement industry. The content of antioxidants in a plant depends on the species, temperature, humidity, period of growth, harvest month, part of the plant used and many other variables. Herein, we present a new method able to determine the all over antioxidative power (AP) of plant extracts or lyophilised plant parts based on the reducing activity against a stable test radical. The method is performed by ESR spectroscopy and is based on the well-known 1,1-diphenyl-2-picryl-hydrazil (DPPH) method with the major difference that both the antioxidative capacity and the antioxidative activity are used to characterise an antioxidant. The resulting antioxidative power is expressed in antioxidative units (AU), where 1AU corresponds to the activity of a 1 ppm solution of Vitamin C as a benchmark. This method allows a rapid, unexpensive and general applicable technique for the measurement of the antioxidative power of very different kinds of substances. The inclusion of the kinetic behaviour of the reducing process of the antioxidant for the determination of the AP allows the identification of the main antioxidant present in a sample. Herein, we present the application example of seeds, sprouts and adult parts of dandelion, amaranth, quinoa, fenugreek, broccoli, red clover and mugwort, where the AP method permits to characterise the plants with the highest antioxidant capacity and reaction velocity. The method permits to select active plant extracts for the food and nutrition industry.

Topics: Antioxidants; Ascorbic Acid; Biphenyl Compounds; Electron Spin Resonance Spectroscopy; Free Radical Scavengers; Free Radicals; Humans; Indicators and Reagents; Picrates; Plant Extracts; Seeds; Trigonella; Vitamin E

The study was carried out to determine the relative efficacies of polyphenolic flavonoids, quercetin, catechin and epicatechin against tert-BOOH induced oxidative stress in human macrophage, U-937 cell line. Exposure of the cells to tert-BOOH oxidative stress resulted in a significant increase in cytotoxicity and reactive oxygen species (ROS) generation. Further, a significant decrease in mitochondrial membrane potential and increase in lipid peroxidation and DNA damage was observed in cells exposed to tert-BOOH. Pretreatment of cells with quercetin, catechin and epicatechin significantly inhibited tert-BOOH induced cytotoxicity by inhibiting ROS generation. The flavonoids inhibited DNA damage induced by tert-BOOH and preserved the mitochondrial transmembrane potential significantly. Epicatechin and catechin were found to be more efficient than quercetin in inhibiting tert-BOOH induced cellular damage.

Topics: Antioxidants; Ascorbic Acid; Biphenyl Compounds; Catechin; Cell Line; Cell Survival; Comet Assay; DNA Damage; Electrophoresis, Polyacrylamide Gel; Flavonoids; Free Radical Scavengers; Humans; Lipid Peroxidation; Macrophages; Membrane Potentials; Mitochondria, Liver; Oxidative Stress; Picrates; Quercetin; tert-Butylhydroperoxide

The aim of this study was to characterize the antioxidant activity of three ascorbic acid (AA) derivatives O-substituted at the C-2 position of AA: ascorbic acid 2-glucoside (AA-2G), ascorbic acid 2-phosphate (AA-2P), and ascorbic acid 2-sulfate (AA-2S). The radical-scavenging activities of these AA derivatives and some common low molecular-weight antioxidants such as uric acid or glutathione against 1,1-diphenyl-picrylhydrazyl (DPPH) radical, 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) radical cation (ABTS+), or galvinoxyl radical were kinetically and stoichiometrically evaluated under pH-controlled conditions. Those AA derivatives slowly and continuously reacted with DPPH radical and ABTS+, but not with galvinoxyl radical. They effectively reacted with DPPH radical under acidic conditions and with ABTS+ under neutral conditions. In contrast, AA immediately quenched all species of radicals tested at all pH values investigated. The reactivity of Trolox, a water-soluble vitamin E analogue, was comparable to that of AA in terms of kinetics and stoichiometrics. Uric acid and glutathione exhibited long-lasting radical-scavenging activity against these radicals under certain pH conditions. The radical-scavenging profiles of AA derivatives were closer to those of uric acid and glutathione rather than to that of AA. The number of radicals scavenged by one molecule of AA derivatives, uric acid, or glutathione was equal to or greater than that by AA or Trolox under the appropriate conditions. These data suggest the potential usage of AA derivatives as radical scavengers.

Topics: Ascorbic Acid; Benzhydryl Compounds; Benzothiazoles; Biphenyl Compounds; Chromans; Free Radical Scavengers; Glutathione; Hydrogen-Ion Concentration; Kinetics; Picrates; Sulfonic Acids; Uric Acid

Antioxidant potential of Aspergillus candidus MTCC 2202 broth filtrate extract was studied using different antioxidant models, whereas anti-inflammatory potential was studied using carrageenan-induced rat paw oedema model. The ethyl acetate extract at 1000 microg/ml showed maximum scavenging activity of the stable radical 1,1-diphenyl,2-picryl hydrazyl upto 96.65% (IC50=430.36 microg/ml) and scavenging of the radical cation, 2,2-azinobis-(3-ethylbenzothiazoline-6-sulphonate) upto 92.25% (IC50=606.29 microg/ml) at the same concentration. The extract had good reducing power, however showed moderate inhibition for conjugated dienes and thiobarbituric acid reactive acid substances (59.56 and 51.45%). The total phenolic content of various extracts of A. candidus broth filtrate was measured and a correlation between radical scavenging activities of extracts with total phenolic content was observed. The ethyl acetate extract (125 mg/kg ip) showed significant anti-inflammatory activity in carrageenan-induced rat paw oedema model. The exhibited antioxidant activity of ethyl acetate extract of A. candidus broth filtrate was comparable with BHA and ascorbic acid, while anti-inflammatory activity was comparable with standard diclofenac sodium.

Topics: Animals; Anti-Inflammatory Agents; Antioxidants; Ascorbic Acid; Aspergillus; Biphenyl Compounds; Butylated Hydroxyanisole; Cations; Culture Media; Diclofenac; Edema; Free Radicals; Hydrazines; Phenol; Picrates; Rats

Glossogyne tenuifolia (Labill) Cass. (Compositae) is a special medicinal plant in the Pescadores Islands. Ethanolic, cold and hot water extracts were prepared from the dried herb and their antioxidant properties and components were studied. Ascorbic acid, alpha-tocopherol, butylated hydroxyanisole, citric and ethylenediaminetetraacetic acids were used in assays for comparison. With regard to EC(50) values in antioxidant activity, ethanolic and hot water extracts (0.08 and 0.09 mg/ml) were much more effective than the cold water extract (0.76 mg/ml). At 1.0 mg/ml, reducing capacities were 1.57, 0.31 and 1.04 for ethanolic, cold water and hot water extracts, respectively. Scavenging abilities on 1,1-diphenyl-2-picrylhydrazyl radicals were in descending order: ethanolic > cold water > hot water extracts. At 20 mg/ml, the hot water extract chelated all hydroxyl ions (100%) whereas the scavenging ability of the cold water extract was 68.86%. Chelating abilities on ferrous ions were in descending order: cold water > hot water > ethanolic extracts. Phenols were found to be the major antioxidant components. All EC(50) values were below 20 mg/ml, and some even below 0.1 mg/ml, indicating that all three extracts from G. tenuifolia were rich in antioxidant properties.

Topics: Antioxidants; Ascorbic Acid; Asteraceae; beta Carotene; Biphenyl Compounds; Chromatography, High Pressure Liquid; Dose-Response Relationship, Drug; Ferrous Compounds; Free Radical Scavengers; Hydrazines; Hydroxyl Radical; Iron Chelating Agents; Oxidation-Reduction; Picrates; Plant Extracts; Tocopherols

One NaCl-tolerant chrysanthemum (Chrysanthemum morifolium Ramat.) variant (E2) has been developed in a stable form through IN VITRO mutagenesis using ethylmethane sulfonate (EMS) as the chemical mutagen. Salt tolerance was evaluated by the capacity of the plant to maintain both flower quality and yield under stress conditions. Enhanced tolerance of the E2 variant has been attributed to the increased activity of superoxide dismutase (SOD), ascorbate peroxidase (APX), and dehydroascorbate reductase (DHAR), and, to a lesser extent of membrane damage than NaCl-treated control plants. Isoform analysis revealed that an increase in total SOD activity in the E2 variant was solely due to significant activation of the Cu/Zn isoform. Elevated levels of carotenoids and ascorbate in E2 leaves have been reflected in their higher free radical scavenging capacity (RSC) expressed in terms of DPPH (2,2-diphenyl-1-picrylhydrazyl) scavenging ability. Data reflect that a proper balance between enzymatic and non-enzymatic defence systems is required for combating salinity stress in chrysanthemum. Better performance of the E2 progeny under same salinity stress condition, even in the second year, confirms the genetic stability of the salt-tolerance character. On the whole, the E2 variant, developed through 0.025 % EMS treatment, might be considered as a NaCl-tolerant strain showing positive characters towards NaCl stress.

Topics: Abscisic Acid; Antioxidants; Ascorbic Acid; Biphenyl Compounds; Carotenoids; Chlorophyll; Chrysanthemum; Electron Transport; Flowers; Hydrogen Peroxide; Isoenzymes; Lipid Peroxidation; Mutagenesis; Peroxidase; Photosystem II Protein Complex; Picrates; Proline; Sodium Chloride

A series of 7-hydroxy-4-oxo-4H-chromene- (3a - h) and 7-hydroxychroman-2-carboxylic acid N-alkyl amides (4a - g) were synthesized and their antioxidant activities were evaluated. While compounds 3a - h were less active, compounds 4a - g exhibited more potent inhibition of lipid peroxidation initiated by Fe2+ and ascorbic acid in rat brain homogenates. Among them, 7-hydroxychroman-2-carboxylic acid N-alkylamides (4e - g) bearing nonyl, decyl, and undecyl side chain exhibited 3 times more potent inhibition than trolox (1).

Topics: Alkanes; Animals; Antioxidants; Ascorbic Acid; Biphenyl Compounds; Chromans; Free Radical Scavengers; Indicators and Reagents; Iron; Lipid Peroxidation; Picrates; Rats

Five new quinone derivatives, (R)-7-hydroxy-alpha-dunnione (1), (R)-8-hydroxy-alpha-dunnione (2), (R)-7,8-dihydroxy-alpha-dunnione (3), (R)-7-methoxy-6,8-dihydroxy-alpha-dunnione (4), and 1,7-dihydroxy-2-hydroxymethylanthraquinone (5), along with seven known compounds, were isolated from Chirita eburnea. All structures were elucidated by spectroscopic techniques (NMR, MS, UV, and IR). The EtOAc fraction of the EtOH extract and compounds 3 and 4 showed free radical (DPPH) scavenging activity, with IC50 values of 101.7 +/- 5.2 microg/mL, 124.82 +/- 8.4 microM, and 45.72 +/- 3.6 microM, respectively, compared with 86.91 +/-6.8 microM for ascorbate.

Topics: Algorithms; Biphenyl Compounds; Drugs, Chinese Herbal; Free Radical Scavengers; Magnoliopsida; Molecular Structure; Nuclear Magnetic Resonance, Biomolecular; Picrates; Plants, Medicinal; Quinones; Stereoisomerism

The n-alkyl esters of gallic acid (CAS 13857-8) have a diverse range of uses as antioxidants in food, cosmetics and pharmaceutical industries. Pharmaceutical studies performed with these compounds have found that they have many therapeutic potentialities including anti-cancer, antiviral and antimicrobial properties. However, more interest has been devoted to their antioxidant activity due to the ability to scavenge and reduce reactive oxygen species (ROS) formation. In this study, gallic acid and 14 different alkyl gallates were tested. The cytotoxicity and anti-herpetic (HSV-1, KOS and 29-R strains) activity were studied by using the MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide) colorimetric assay and the cell viability by using the Trypan blue dye exclusion method. The genotoxicity was studied by the Comet assay and the antioxidant activity by using the DPPH (1,1-diphenyl-2-picrylhydrazyl) radical scavenging and microsomal lipid peroxidation-inhibiting activities. The results showed that all the tested compounds have anti-herpetic activity at non cytotoxic concentrations with selectivity indices (SI = CC50/EC50) varying from 0.89 to 18.34, depending on the used HSV-1 strain. It was observed that all tested alkyl gallates showed some degree of genotoxicity, at the tested concentrations, except cetyl gallate, at 256.60 micromol/L (p <0.05, t-Student test), probably induced by ROS released by infected cells and/or by the alkyl gallates that were not antioxidants, at the tested concentrations, in which they demonstrated anti-herpetic activity. The hydroxyl groups can induce DNA damage due interactions with some metal ions, which are naturally present in the culture medium supplemented with fetal bovine serum, probably explaining the genotoxicity detected. However, the obtained results showed considerable antioxidant activity at smaller concentrations, when compared to quercetin which is considered as a reference drug due to its already described antioxidant potential: DPPH radical scavenging activity with IC50 values varying from 17 to 31 micromol/L; and microsomal lipid peroxidation-inhibiting activity with IC50 values varying from 21 to 59 micromol/L. It was observed that the presence of hydroxyl groups in these molecules is important for their pharmacological profile, but the length of the lateral carbonic chain does not have considerable influence.

Topics: Animals; Antineoplastic Agents; Antioxidants; Antiviral Agents; Ascorbic Acid; Biphenyl Compounds; Cell Survival; Cells, Cultured; Chlorocebus aethiops; Comet Assay; Free Radical Scavengers; Gallic Acid; Herpesviridae; Humans; Indicators and Reagents; Lipid Peroxidation; Microsomes, Liver; Mutagens; Picrates; Solutions; Vero Cells

The chemical composition of the essential oil obtained from Teucrium marum subsp. marum (Lamiaceae) was analysed by GC/MS and 30 components were identified. Isocaryophyllene (20.24%), beta-bisabolene (14.73%), beta-sesquiphellandrene (11.27%), alpha-santalene (10.97%), dolichodial (9.38%) and, alpha-caryophyllene (7.18%) were the main components. The antimicrobial activity of the essential oil was assayed against four phytopathogenic fungi and Rhyzoctonia solani resulted to be the most sensitive microorganism with a MIC value of 250 ppm. The antioxidant activity of the essential oil was evaluated using the DPPH test, 5-lipoxygenase test and luminol/xanthine/xanthine oxidase chemiluminescence assay.

Topics: Antioxidants; Ascorbic Acid; Biphenyl Compounds; Butylated Hydroxytoluene; Chromans; Drug Evaluation, Preclinical; Fatty Acids; Free Radical Scavengers; Fungicides, Industrial; Inhibitory Concentration 50; Microbial Sensitivity Tests; Mitosporic Fungi; Monoterpenes; Mycoses; Picrates; Plant Components, Aerial; Plant Diseases; Plant Oils; Sesquiterpenes; Superoxides; Teucrium

The free radical scavenging properties of retinyl ascorbate (RA-AsA) were determined by monitoring the decomposition of 2,2-diphenyl-1-picrylhydrazyl (DPPH) as a function of time and in comparison with ascorbic acid (AsA), ascorbic acid palmitate (AsA-Pal), retinoic acid (RA), retinol (ROL) and retinol palmitate (Rol-Pal). The rate constant of RA-AsA (mean3+/-SD) was 4.9+/-0.3 M(-1) s(-1), and indicated greater potency as an antioxidant compared to the rest of the test compounds (AsA 3.4+/-0.4 M(-1) s(-1), AsA-Pal, 2.9+/-0.2 M(-1) s(-1), RA 1.4+/-0.3 M(-1) s(-1), ROL 1.3+/-0.1 M(-1) s(-1), Rol-Pal exhibited insignificant activity). The decomposition rate constant of DPPH, 5+/-0.6 x 10(-8) M(-1) s(-1), in ethanol and BHA, 154+/-3 M(-1) s(-1) were both used as control. The compound RA-2-carboxy-2-hydroxy-ethanoate was isolated by prep-TLC and was identified, by 13C and 1HNMR spectroscopy, as the major by-product from the reaction of RA-AsA with DPPH, which was also found to be potent antioxidant, 2.1+/-0.2 M(-1) s(-1). This suggests that oxidation of AsA moiety did not lead to the production of erythrulose species, which could cause deleterious modifications of cellular proteins.

Topics: Administration, Topical; Ascorbic Acid; Biphenyl Compounds; Diterpenes; Free Radical Scavengers; Hydrazines; Picrates; Retinoids; Retinyl Esters; Tretinoin; Vitamin A

The antioxidant properties of amla extracts and their effects on the oxidative stress in streptozotocin-induced diabetes were examined in rats. Amla in the form of either the commercial enzymatic extract SunAmla (Taiyo Kagaku Co. Ltd., Yokkaichi, Japan) (20 or 40 mg/kg of body weight/day) or a polyphenol-rich fraction of ethyl acetate extract (10 or 20 mg/kg of body weight/day) was given orally for 20 days to the streptozotocin-induced diabetic rats. Amla extracts showed strong free radical scavenging activity. Amla also showed strong inhibition of the production of advanced glycosylated end products. The oral administration of amla extracts to the diabetic rats slightly improved body weight gain and also significantly alleviated various oxidative stress indices of the serum of the diabetic rats. The elevated serum levels of 5-hydroxymethylfurfural, which is a glycosylated protein that is an indicator of oxidative stress, were significantly reduced dose-dependently in the diabetic rats fed amla. Similarly, the serum level of creatinine, yet another oxidative stress parameter, was also reduced. Furthermore, thiobarbituric acid-reactive substances levels were significantly reduced with amla, indicating a reduction in lipid peroxidation. In addition, the decreased albumin levels in the diabetic rats were significantly improved with amla. Amla also significantly improved the serum adiponectin levels. These results form the scientific basis supporting the efficacy of amla for relieving the oxidative stress and improving glucose metabolism in diabetes.

Topics: Adiponectin; Animals; Ascorbic Acid; Biphenyl Compounds; Body Weight; Creatinine; Diabetes Mellitus, Experimental; Drinking; Eating; Flavonoids; Glycation End Products, Advanced; Glycopyrrolate; Intercellular Signaling Peptides and Proteins; Male; Organ Size; Oxidative Stress; Phenols; Phyllanthus emblica; Picrates; Plant Extracts; Polyphenols; Rats; Rats, Wistar; Serum Albumin; Thiobarbituric Acid Reactive Substances

A new diketopiperazine alkaloid, golmaenone (1). and related alkaloids, neoechinulin A (2). and L-alanyl-L-tryptophan anhydride (3). have been isolated from the culture broth of the marine-derived fungus Aspergillus sp. The structure and absolute stereochemistry of the new compound (1). was assigned by spectroscopic methods and the advanced Marfey's method. Compounds 1 and 2 exhibited a significant radical scavenging activity against 1,1-diphenyl-2-picrylhydrazyl (DPPH) with IC(50) values of 20 and 24 microM, respectively, which are similar to the positive control, ascorbic acid (IC(50), 20 microM). Compounds 1 and 2 also showed an ultraviolet-A (UV-A) (320--390 nm) protecting activity with ED(50) values of 90 and 170 microM, respectively, which are more active than oxybenzone (ED(50), 350 microM) currently being used as sunscreen.

Topics: Ascorbic Acid; Aspergillus; Benzophenones; Biphenyl Compounds; Dipeptides; Free Radical Scavengers; Indole Alkaloids; Inhibitory Concentration 50; Molecular Structure; Nuclear Magnetic Resonance, Biomolecular; Peptides, Cyclic; Picrates; Piperazines; Sunscreening Agents; Ultraviolet Rays

This study investigates a semicontinuous hot pressurized fluid extraction process and the scavenging activity on the 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical of the extract from Taiwan yams (Dioscorea alata). Liquid-liquid extractions were preliminarily employed to generate six fractions, initially extracted by ethanol. Then, the aqueous solution of dried crude ethanol extract was sequentially fractionated by hexane, chloroform, ethyl acetate, and n-butanol. The EC50 value was defined as the UV absorption of DPPH concentrations sufficiently decreased to 50% of the original value. It was found that all peel portions have a better effect on scavenging of the DPPH free radical than meat portions, especially for the ethyl acetate partition of the peel portion of Tainung #2 yam. Its EC50 value (14.5 microg mL(-1)) was even lower than that of ascorbic acid (21.4 microg mL(-1)). Furthermore, semicontinuous hot pressurized ethanol was superior to hot pressurized water in extracting the compound scavenging the DPPH radical from the Purpurea-Roxb peel. The recovery of four unknown compounds corresponded to the scavenging ratio of DPPH free radical in the hot pressurized ethanol extract. Finally, three-level and four-factor experimental design revealed that ethanol ratio and temperature were the most effective factors in order. Conditions of 80% of aqueous ethanol, 20.0 kg/kg solid ratio, 180 psig (1.342 MPa), and 100 degrees C were preferred to extract those antioxidants from the yam peel.

Topics: Ascorbic Acid; Biphenyl Compounds; Dioscorea; Ethanol; Free Radical Scavengers; Hot Temperature; Picrates; Plant Extracts; Plant Structures; Pressure; Water

Dried ground leaves of Psidium guajava L. (guava) were extracted by water and aqueous ethyl alcohol 50% (1:10) ratio, and the total phenolic content in the extracts was determined spectrophotometrically according to Folin- Ciocalteu's phenol method and calculated as gallic acid equivalent (GAE). Remarkably high total phenolic content 575.3 +/-15.5 and 511.6+/-6.2 mg of GAE/g of dried weight material (for ethanol guava leaf extracts and water guava leaf extracts, respectively) were obtained. The antioxidant activity of lyophilized extracts was determined at ambient temperature by means of a 2,2-diphenyl-1-picrylhydryzyl (DPPH*) colorimetry with detection scheme at 515 nm. The activity was evaluated by the decrease in absorbance as the result of DPPH* color change from purple to yellow. The higher the sample concentration used, the stronger was the free radical-scavenging effect. The results obtained showed that ascorbic acid was a substantially more powerful antioxidant than the extracts from guava leaf. On the other hand, the commercial guava leaf extracts and ethanol guava leaf extracts showed almost the same antioxidant power whereas water guava leaf extracts showed lower antioxidant activity. The parameter EC(50) and the time needed to reach the steady state to EC(50) concentration (T(EC(50))) affected the antiradical capacity of the sample. The antioxidant efficiency (AE) has been shown to be a more adequate parameter for selecting antioxidants than the widely used EC(50). This study revealed that guava leaf extracts comprise effective potential source of natural antioxidants.

Topics: Antioxidants; Ascorbic Acid; Biphenyl Compounds; Picrates; Plant Extracts; Plant Leaves; Psidium; Time Factors

The formation of complexes of metal ions with the flavonoids quercetin (L1), rutin (L2), galangin (L3) and catechin (L4) has been investigated by UV-visible spectroscopy. The antioxidant activities of the compounds were evaluated by using the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicalscavenging method. In this work, we have shown that the complexed flavonoids are much more effective free radical scavengers than the free flavonoids. We suggest that the higher antioxidant activity of the complexes is due to the acquisition of additional superoxide dismutating centers. Radical scavenging activities of the compounds were also investigated from an electrochemical point of view. There is a relationship between the logarithm of the antioxidant activity (represented by EC50) and the oxidation potential. The synergic effect of the complexes and ascorbic acid were studied by [13C]-NMR analyses. The results show that ascorbic acid can protect flavonoids from oxidative degradation, and reveal antioxidant synergies between ascorbic acid and the compounds.

Topics: Antioxidants; Ascorbic Acid; Biphenyl Compounds; Catechin; Drug Synergism; Flavonoids; Free Radical Scavengers; Magnetic Resonance Spectroscopy; Metals; Oxidation-Reduction; Picrates; Quercetin; Reactive Oxygen Species; Rutin; Superoxide Dismutase

Pure natural products isolated from marine sponges, algae, and cyanobacteria were examined for antioxidant activity using a 2,2-diphenyl-1-picrylhydrazyl radical (DPPH) solution-based chemical assay and a 2',7'-dichlorodihydrofluorescein diacetate (DCFH-DA) cellular-based assay. The DCFH system detects only antioxidants that penetrate cellular membranes. Potent antioxidants were identified and the results from each system compared. The algal metabolites cymopol (1), avrainvilleol (3), and fragilamide (4), and the invertebrate constituent puupehenone (5) showed strong antioxidant activity in both systems. Several compounds were active in the DPPH assay but significantly less active in the DCFH system. The green algal metabolite 7-hydroxycymopol (2) was isolated from Cymopolia barbataand its structure determined. Compound 2 was significantly less active in the DCFH system than cymopol (1). The sponge metabolites (1S)-(+)-curcuphenol (6), aaptamine (7), isoaaptamine (8), and curcudiol (9) and the cyanobacterial pigment scytonemin (10) showed strong antioxidant activity in the DPPH assay, but were relatively inactive in the DCFH system. Thus, cellular uptake dramatically affects the potential significance of antioxidants discovered using only the DPPH assay. The apparent "proantioxidants" hormothamnione A diacetate (11) and Laurencia monomer diacetate (12) require metabolic activation for antioxidant activity. Significant advantages are achieved using both a solution- and cellular-based assay to discover new antioxidants.

Topics: Animals; Antioxidants; Biological Products; Biphenyl Compounds; Cyanobacteria; Eukaryota; Jamaica; Molecular Structure; Nuclear Magnetic Resonance, Biomolecular; Picrates; Porifera; Stereoisomerism

A sulfated emodin glucoside, emodin 8-O-beta-D-glucopyranosyl-6-O-sulfate (1), was isolated from the roots of Rheum emodi in an investigation of the active constituents of this Nepalese medicinal plant, and its structure was determined by spectroscopic and chemical methods. Additionally, two rare auronols, carpusin (2) and maesopsin (3), besides other anthraquinones and phenolics, were isolated and identified. Compounds 2 and 3 showed significant antioxidant activity in the DPPH assay, while chrysophanol, physcion, and emodin and their 8-O-glucosides were found to be inactive.

Topics: Anthraquinones; Antioxidants; Benzofurans; Biphenyl Compounds; Glycosides; Inhibitory Concentration 50; Molecular Structure; Nepal; Nuclear Magnetic Resonance, Biomolecular; Picrates; Plant Roots; Plants, Medicinal; Rheum

The free radical scavenging activity of South African red (n = 46) and white (n = 40) cultivar wines was determined using 2,2'-azinobis(3-ethylbenzothialozinesulfonic acid) radical cations (ABTS(.+)) and 2,2-diphenyl-1-picrylhydrazyl radicals (DPPH.). The total antioxidant activities (TAA) of red and white wines using ABTS(.+) were 14.916 and 0.939 mM Trolox, respectively, at corresponding total phenol (TP) contents of 2339.0 and 273.8 mg of gallic acid equiv/L. Ruby Cabernet wines had the lowest TAA(ABTS) (13.177 mM Trolox) of the red wines, whereas the TAA(ABTS) values of Chardonnay and Chenin blanc wines were the highest (1.060 mM Trolox) and lowest (0.800 mM Trolox) of the white wines. The TAA(DPPH) values were of the same magnitude as the TAA(ABTS) values, and similar trends were observed. TAA correlated (P < 0.001) with total phenol content of red (r = 0.935) and white (r = 0.907) wines, as well as flavanol content of red wines (r = 0.866) and tartaric acid ester content of white wines (r = 0.767). Canonical discriminant analysis using phenolic composition and antioxidant activity was applied to differentiate between red and white cultivar wines.

Topics: Anthocyanins; Antioxidants; Ascorbic Acid; Benzothiazoles; Biphenyl Compounds; Discriminant Analysis; Free Radical Scavengers; Fruit; Phenols; Picrates; South Africa; Sulfonic Acids; Vitis; Wine

The antioxidant capacity of butylated hydroxytoluene (BHT; 2,6-di-tert-butyl-p-cresol), propyl gallate (3,4,5-trihydroxybenzoic acid n-propyl ester), resveratrol (trans-3,4',5-trihydroxystilbene), and vitamins C (l-ascorbic acid) and E [(+)-alpha-tocopherol] was studied in chemical and biological systems. The chemical assays evaluated the capacity of these antioxidants to sequester 2,2'-azinobis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS.) and 1,1 diphenyl-2-picrylhydrazyl (DPPH.). A new colorimetric method to determine hydroxyl radical scavenging is also described. The biological tests use the eucaryotic cells of Saccharomyces cerevisiae treated with the antioxidants in the presence of the stressing agents apomorphine, hydrogen peroxide, and paraquat dichloride (methylviologen; 1,1'-dimethyl-4,4'-bipyridinium dichloride). The results in chemical systems showed that all of the antioxidants were able to significantly inhibit the oxidation of beta-carotene by hydroxyl free radicals. The assays in yeast showed that the antioxidant activity of the tested compounds depended on the stressing agent used and the mechanism of action of the antioxidant.

Topics: Antioxidants; Apomorphine; Ascorbic Acid; Benzothiazoles; beta Carotene; Biphenyl Compounds; Butylated Hydroxytoluene; Hydrogen Peroxide; Hydroxyl Radical; Oxidation-Reduction; Paraquat; Picrates; Propyl Gallate; Resveratrol; Saccharomyces cerevisiae; Stilbenes; Sulfonic Acids; Vitamin E

4-(4-Hydroxyphenyl)-5-(4-hydroxyphenylmethyl)-2-hydroxyfurane-2-one 1 was prepared by an acidic dimerisation of 4-hydroxyphenylpyruvic acid and some of its antioxidant and spectroscopic properties have been measured and compared to that of ascorbic acid. 1 is as good an antioxidant as ascorbic acid in the DPPH (2,2-diphenyl-1-picryl hydrazyl radical) test and the inhibition of hydroxyl radical and a powerful inhibitor of the Cu(2+) or AAPH (2,2'-azobis-(2-amidinopropane) dihydrochloride) induced oxidation of human LDL. 1 gives a stable radical characterised by its ESR spectrum similarly to ascorbic acid but in lower concentration and with a different reactivity towards nitroxides. Theoretical calculations allow us to propose the structure for the radical formed from 1, to explain its lower stability than ascorbyl radical and to evaluate the lipophilicity of 1.

Topics: Amidines; Antioxidants; Ascorbic Acid; Biphenyl Compounds; Chemical Phenomena; Chemistry, Physical; Cholesterol, LDL; Copper; Electromagnetic Fields; Electron Spin Resonance Spectroscopy; Furans; Humans; Hydroxyl Radical; Indicators and Reagents; Lipids; Models, Molecular; Molecular Conformation; Picrates; Spectrophotometry, Ultraviolet

Four aqueous extracts from different parts of medicinal plants used in Ayurveda (an ancient Indian Medicine) viz., Momardica charantia Linn (AP1), Glycyrrhiza glabra (AP2), Acacia catechu (AP3), and Terminalia chebula (AP4) were examined for their potential as antioxidants. The antioxidant activity of these extracts was tested by studying the inhibition of radiation induced lipid peroxidation in rat liver microsomes at different doses in the range of 100-600 Gy as estimated by thiobarbituric acid reactive substances (TBARS). Of all these extracts, AP4 showed maximum inhibition in the TBARS formation and hence is considered the best antioxidant among these four extracts. The extracts were found to restore antioxidant enzyme superoxide dismutase (SOD) from the radiation induced damage. The antioxidant capacities were also evaluated in terms of ascorbate equivalents by different methods such as cyclic voltammetry, decay of ABTS(.-) radical by pulse radiolysis and decrease in the absorbance of DPPH radicals. The results were found to be in agreement with the lipid peroxidation data and AP4 showed maximum value of ascorbate equivalents. Therefore AP4, with high antioxidant activity, is considered as the best among these four extracts.

Topics: Animals; Antioxidants; Ascorbic Acid; Biphenyl Compounds; Dose-Response Relationship, Drug; Electrochemistry; Free Radicals; Gamma Rays; Inhibitory Concentration 50; Kinetics; Lipid Peroxidation; Medicine, Ayurvedic; Microsomes, Liver; Mitochondria, Liver; Picrates; Plant Extracts; Plants, Medicinal; Pulse Radiolysis; Rats; Superoxide Dismutase; Thiobarbituric Acid Reactive Substances

Water, aqueous methanol, and aqueous ethanol extracts of freeze-dried leaves of Moringa oleifera Lam. from different agroclimatic regions were examined for radical scavenging capacities and antioxidant activities. All leaf extracts were capable of scavenging peroxyl and superoxyl radicals. Similar scavenging activities for different solvent extracts of each collection were found for the stable 1,1-diphenyl 2-picrylhydrazyl (DPPH(*)) radical. Among the three different moringa samples, both methanol and ethanol extracts of Indian origins showed the highest antioxidant activities, 65.1 and 66.8%, respectively, in the beta-carotene-linoleic acid system. Nonetheless, increasing concentration of all the extracts had significantly (P < 0.05) increased reducing power, which may in part be responsible for their antioxidant activity. The major bioactive compounds of phenolics were found to be flavonoid groups such as quercetin and kaempferol. On the basis of the results obtained, moringa leaves are found to be a potential source of natural antioxidants due to their marked antioxidant activity. This is the first report on the antioxidant properties of the extracts from freeze-dried moringa leaves. Overall, both methanol (80%) and ethanol (70%) were found to be the best solvents for the extraction of antioxidant compounds from moringa leaves.

Topics: Adenosine Diphosphate; Antioxidants; Ascorbic Acid; beta Carotene; Biphenyl Compounds; Chromatography, High Pressure Liquid; Ferric Compounds; Flavonoids; Free Radical Scavengers; Hydrogen Peroxide; Linoleic Acid; Lipid Peroxidation; Moringa oleifera; NADP; Oxidation-Reduction; Phenols; Picrates; Plant Extracts; Plant Leaves; Reducing Agents; Solvents; Superoxides

Antioxidant activity of betalain pigments (seven pure compounds and four combined fractions) from plants of the family Amaranthaceae was evaluated using the modified DPPH(*) (1,1-diphenyl-2-picrylhydrazyl) method. All tested betalains exhibited strong antioxidant activity. Their EC(50) values ranged from 3.4 to 8.4 microM. Gomphrenin type betacyanins (mean = 3.7 microM) and betaxanthins (mean = 4.2 microM) demonstrated the strongest antioxidant activity, 3-4-fold stronger than ascorbic acid (13.9 microM) and also stronger than rutin (6.1 microM) and catechin (7.2 microM). Antioxidant activity of the tested betalains decreased in the following order: simple gomphrenins > acylated gomphrenins > dopamine-betaxanthin > (S)-tryptophan-betaxanthin > 3-methoxytyramine-betaxanthin > betanin/isobetanin > celosianins > iresinins > amaranthine/isoamaranthine. This study also investigated and discussed the relationship between the chemical structure and the activity of the betalains. The free radical scavenging activity of the betalains usually increased with the numbers of hydroxyl/imino groups and, moreover, depended on the position of hydroxyl groups and glycosylation of aglycones in the betalain molecules.

Topics: Amaranthaceae; Antioxidants; Ascorbic Acid; Betalains; Biphenyl Compounds; Chromatography, High Pressure Liquid; Free Radical Scavengers; Picrates; Plant Extracts; Quaternary Ammonium Compounds; Structure-Activity Relationship

The Kampo medicine, Ninjin-yoei-to, scavenged 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals in a dose-dependent fashion as did ascorbic acid and alpha-tocopherol. Ninjin-yoei-to, which is composed of 12 herbs, had a potent DPPH radical scavenging ability. We investigated the transition of the materials that scavenge DPPH radicals in plasma after oral administration of Ninjin-yoei-to to rats. When 1.0 g kg(-1) Ninjin-yoei-to was administered, the DPPH radical scavenging ability increased at 30 min and biphasic peaks were observed at 2 h and at 10 h. From the response-time profile, kinetic parameters including values for K(a) (absorption rate constant), t(max) (peak concentration time), t(1/2) (half-life) and MRT (mean residence time) of the radical scavenging ability in plasma could be calculated for DPPH radicals. K(a) values were 0.53 +/- 0.03 and 0.36 +/- 0.07 h, t(max) values were 2.1 +/- 1.04 and 8.56 +/- 2.69 h, t(1/2) values were 1.60 +/- 0.12 and 3.39 +/- 1.72 h, and MRT values were 4.14 +/- 1.59 and 8.18 +/- 2.55 h, respectively. These parameters calculated from the antioxidation dynamics were considered to offer a very meaningful procedure for examining the effects of Ninjin-yoei-to.

Topics: Animals; Antioxidants; Ascorbic Acid; Biphenyl Compounds; Drugs, Chinese Herbal; Free Radical Scavengers; Kinetics; Male; Picrates; Rats; Rats, Wistar; Vitamin E

Tender Cocos nucifera L. (Palmacea) water (CW), variety Chandrasankara, was tested for its ability to scavenge free radicals, inhibit lipid peroxidation and protect hemoglobin from nitrite-induced oxidation. Fresh sample of CW scavenged 1,1-diphenyl-2-picrylhydrazyl (DPPH), 2,2'-azino-bis(3-ethylbenz-thiazoline-6-sulfonic acid) (ABTS) and superoxide radicals but promoted the production of hydroxyl radicals and increased lipid peroxidation. The activity was most significant for fresh samples of CW and diminished significantly upon heat, acid or alkali treatment or dialysis. Maturity of coconut drastically decreased the scavenging ability of CW against DPPH, ABTS and superoxide radicals. CW protected hemoglobin from nitrite-induced oxidation to methemoglobin when added before the autocatalytic stage of the oxidation. Acid, alkali or heat treated or dialyzed CW showed a decreased ability in protecting hemoglobin from oxidation. The scavenging ability and protection of hemoglobin from oxidation may be partly attributed to the ascorbic acid, which is an important constituent of CW. As CW is a rich source of vitamins, amino acids and enzymes, etc., more than one active principle maybe involved.

Topics: Animals; Antioxidants; Ascorbic Acid; Benzothiazoles; Biphenyl Compounds; Cocos; Erythrocytes; Female; Free Radical Scavengers; Hemoglobins; Hot Temperature; Hydrazines; Hydrogen-Ion Concentration; Hydroxyl Radical; Kinetics; Lipid Peroxidation; Male; Methemoglobin; Oxidation-Reduction; Picrates; Plant Extracts; Rats; Sulfonic Acids; Superoxides

Several extracts from marine brown alga Sargassum micracanthum (Kuetzing) Endlicher were screened for their inhibitory activity on lipid peroxidation. In an in vitro study, methanol extract (Sm-M), chloroform/ methanol (3:1) extract and ethyl acetate fraction of Sm-M inhibited lipid peroxidation in rat liver homogenates. The IC(50) values were 0.70, 0.70 and 0.37 micro g/mL, respectively. These inhibitions were stronger than vitamin C and E. These extracts showed reductive activity on DPPH, the IC(50) values were 34, 37 and 11 micro g/mL, respectively. In an in vivo study, Sm-M had the effect on CCl4 induced liver injury in rats and Sm-M (120-1200 mg/kg, p.o.) lowered dose-dependently the level of lipid peroxidation in liver.

Topics: Animals; Antioxidants; Ascorbic Acid; Biphenyl Compounds; Carbon Tetrachloride; Dose-Response Relationship, Drug; Hydrazines; Inhibitory Concentration 50; Lipid Peroxidation; Liver; Male; Phaeophyceae; Picrates; Rats; Rats, Wistar; Vitamin E

The antioxidant activities of different drugs like acetylsalicylic acid, nimesulide, dapsone, methlydopa, rifampicin and the well known antioxidants ascorbic acid and quercetin were assessed using the stable free radical alpha,alpha-diphenyl-beta-picrylhydrazyl (DPPH). DPPH is easily soluble at lower concentrations in methanol. It has a deep violet color. The changes in color are monitored calorimetrically. The measurements were made using HPLC at wavelengths 256 nm and 517 nm. The interactions between different drugs with DPPH were studied. All the compounds tested reduced DPPH. This method can be used to investigate oxygen free radical scavenging activity of drug candidates.

Topics: Antioxidants; Ascorbic Acid; Aspirin; Biphenyl Compounds; Chromatography, High Pressure Liquid; Dapsone; Free Radicals; Methyldopa; Picrates; Quercetin; Rifampin; Spectrophotometry, Ultraviolet; Sulfonamides

The lignan otobaphenol, (8R,8'R,7R)-4'-hydroxy-5'-methoxy-3,4-methylenedioxy-2',7,8,8'-neolignan, extracted from Virola Aff. Pavonis leaves, completely inhibits at a concentration of 2.5 micro M the Fe(3+)-ascorbate-induced lipoperoxidation of rat liver mitochondria that was determined by oxygen consumption and accumulation of thiobarbituric acid-reactive species. At 25 micro M, it delays the mitochondrial permeability transition induced by tert-butyl hydroperoxide or Ca(2+), substantially inhibits the state 3 respiration, does not affect the state 4 respiration and the ADP/O ratio (with succinate), diminishes the rate of Ca(2+) uptake by mitochondria, and delays the ruthenium red-insensitive uncoupler-induced release of the loaded Ca(2+). Dose-dependent delaying of the calcium-induced swelling of mitochondria in the presence of otobaphenol nonlinearly correlates with its 1,1-diphenyl-2-picrylhydrazyl free radical scavenging activity. At 75 micro M and higher, this lignan causes mitochondrial aggregation and is able to aggregate itself, without mitochondria. The formed aggregates of otobaphenol do not cause an aggregation of subsequently added mitochondria. Thus, otobaphenol seems to be a promising target to prevent the oxidative stress death of cells.

Topics: Animals; Antioxidants; Ascorbic Acid; Biphenyl Compounds; Butylated Hydroxytoluene; Calcium; Cell Membrane Permeability; Ferric Compounds; Free Radical Scavengers; Intracellular Membranes; Lipid Peroxidation; Male; Membrane Potentials; Mitochondria, Liver; Mitochondrial Swelling; NADP; Oxidative Phosphorylation; Oxygen Consumption; Phenols; Picrates; Rats; tert-Butylhydroperoxide; Thiobarbituric Acid Reactive Substances; Time Factors

Fruiting bodies of Phellinus linteus were extracted with 70% ethanol at room temperature. The Phellinus linteus extract (PL) showed strong anti-angiogenic activity, which was detected using the chick embryo chorioallantoic membrane (CAM) assay. The in vitro antioxidant activities of PL were evaluated using two different bioassays. PL was comparable to Vitamin C in scavenging the stable free radical 1,1-diphenyl-2-picrylhyrazyl (DPPH). It also inhibited lipid peroxidation (LPO) in a concentration-dependent manner. These results suggest that antioxidant and anti-angiogenic activities of Phellinus linteus would be partly responsible for its anti-tumor effect.

Topics: Agaricales; Angiogenesis Inhibitors; Animals; Antioxidants; Ascorbic Acid; Biphenyl Compounds; Brain; Chick Embryo; Free Radical Scavengers; Hydrazines; Korea; Lipid Peroxidation; Picrates; Rats; Rats, Sprague-Dawley; Xanthine Oxidase

The antioxidant properties of green, black and mixed (fruit) tea samples of different origin were investigated by means of EPR spectroscopy. A six line EPR spectrum of solid tea samples indicates the presence of Mn(II) ions and it is superimposed with a sharp singlet line attributed to semiquinone radical species (Delta H(pp)=1 mT; g=2.0022). Antioxidant properties of aqueous tea extracts in H(2)O(2)/NaOH/dimethylsulfoxide system generating reactive radicals (*OH, O(2)*-), *CH(3)) were followed by spin trapping technique. In addition, antioxidant capacity of these samples was assessed using stable radicals 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 4-hydroxy-2,2,6,6-tetramethyl-1-piperidinyloxy (TEMPOL). Typically, the highest antioxidant potential to terminate superoxide radicals was found in green teas, followed by black and fruity teas. The pro-oxidant activity of green teas evidenced by spin traps was promoted in samples with higher Mn(II) and ascorbic acid concentrations. Various sources of free radicals used in the antioxidant tests due to their specific action show different termination rates in the presence of the individual tea samples.

Topics: Antioxidants; Ascorbic Acid; Biphenyl Compounds; Cyclic N-Oxides; Electron Spin Resonance Spectroscopy; Free Radical Scavengers; Hydrogen-Ion Concentration; Kinetics; Manganese; Molecular Structure; Picrates; Plant Extracts; Spin Labels; Tea; Water

Since reactive oxygen species (ROS) and hydroxyl radicals (*OH) play an important role in the pathogenesis of many human degenerative diseases, much attention has focused on the development of safe and effective antioxidants. Preliminary experiments have revealed that the methanol (MeOH) extract of the stem of Prunus davidiana exerts inhibitory/scavenging activities on 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals, total ROS and peroxynitrites (ONOO-). In the present study, the antioxidant activities of this MeOH extract and the organic solvent-soluble fractions, dichloromethane (CH2Cl2), ethyl acetate (EtOAc), and n-butanol (n-BuOH), and the water layer of P. davidiana stem were evaluated for the potential to inhibit *OH and total ROS generation in kidney homogenates using 2',7'-dichlorodihydrofluorescein diacetate (DCHF-DA), and for the potential to scavenge authentic ONOO-. We also evaluated the inhibitory activity of seven flavonoids isolated from P. davidiana stem, kaempferol, kaempferol 7-O-beta-D-glucoside, (+)-catechin, dihydrokaempferol, hesperetin 5-O-beta-D-glucoside, naringenin and its 7-O-beta-D-glucoside, on the total ROS, *OH and ONOO- systems. For the further elucidation of the structure-inhibitory activity relationship of flavonoids on total ROS and *OH generation, we measured the antioxidant activity of sixteen flavonoids available, including three active flavonoids isolated from P. davidiana, on the total ROS and *OH systems. We found that the inhibitory activity on total ROS generation increases in strength with more numerous hydroxyl groups on their structures. Also, the presence of an ortho-hydroxyl group, whether on the A-ring or B-ring, and a 3-hydroxyl group on the C-ring increased the inhibitory activity on both total ROS and *OH generation.

Topics: 1-Butanol; Acetates; Animals; Antioxidants; Ascorbic Acid; Biphenyl Compounds; Catechin; Chromans; Drug Evaluation, Preclinical; Flavonoids; Free Radical Scavengers; Hesperidin; Hydrazines; Hydroxyl Radical; Kaempferols; Kidney; Male; Methanol; Methylene Chloride; Penicillamine; Peroxynitrous Acid; Picrates; Plant Extracts; Plant Stems; Prunus; Rats; Rats, Wistar; Reactive Oxygen Species; Structure-Activity Relationship; Water

In the present study, essential oil from the leaves of Syrian oreganum [Origanum syriacum L. (Lauraceae)] grown in Turkish state forests of the Dortyol district, Turkey, was obtained by steam distillation. The chemical composition of oil was analysed by GC and GC-MS, and was found to contain 49.02% monoterpenes, 36.60% oxygenated monoterpenes and 12.59% sesquiterpenes. The major components are as follows: gamma-terpinene, carvacrol, p-cymene and beta-caryophyllene. Subsequently, the reducing power, antioxidant and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical-scavenging activities of the essential oil were studied. The reducing power was compared with ascorbic acid, and the other activities were compared with 2,6-di-tert-butyl-4-methyl phenol (BHT, butylated hydroxytoluene). The results showed that the activities were concentration dependent. The antioxidant activities of the oil were slightly lower than those of ascorbic acid or BHT, so the oil can be considered an effective natural antioxidant. Antimicrobial activities of the essential oil from the leaves of Origanum syriacum was also determined on 16 microorganisms tested using the agar-disc diffusion method, and showed antimicrobial activity against 13 of these.

Topics: Ampicillin; Anti-Infective Agents; Antioxidants; Ascorbic Acid; Biphenyl Compounds; Cyclohexane Monoterpenes; Cymenes; Dose-Response Relationship, Drug; Drug Evaluation, Preclinical; Escherichia coli; Free Radical Scavengers; Klebsiella pneumoniae; Micrococcus luteus; Monoterpenes; Nystatin; Oils, Volatile; Origanum; Picrates; Plant Leaves; Plant Oils; Plants, Medicinal; Polycyclic Sesquiterpenes; Sesquiterpenes; Staphylococcus aureus; Streptomycin; Turkey

An attempt to synthesize 6-hydroxypyridoxine (OPN), hydroxylation on C-6 of pyridoxine (PN) by hydroxyl radical (OH*). was conducted. Application of two well-known OH* generating reactions, i.e. the Fenton reaction and the Fe2+-EDTA/ascorbate reaction, were unsuccessful, as large amounts of by-products were formed. Although generation of OH* by autoxidation of ascorbic acid in the absence of metal ions was slow, by-products were formed in small quantities, and OPN was easily obtained in colorless crystals. Its structure was confirmed by spectral analyses. OPN was comparable to polyphenols such as (+)-catechin, rutin and gallic acid in the antioxidative activity against linoleic acid peroxidation, and was an effective DPPH radical scavenger, though the DPPH radical-scavenging activity of OPN was somewhat lower than that of the polyphenols. PN was relatively inactive under the conditions used here, indicating that the introduction of a hydroxyl group on C-6 of PN greatly enhanced both activities.

Topics: Antioxidants; Ascorbic Acid; Biphenyl Compounds; Crystallization; Edetic Acid; Ferrous Compounds; Flavonoids; Free Radical Scavengers; Hydroxyl Radical; Hydroxylation; Linoleic Acid; Oxidation-Reduction; Phenols; Picrates; Polyphenols; Pyridoxine

Bioassy-directed fractionation of a culture broth of Penicillium citrinum F5 led to the isolation of a novel antioxidant 2,3,4-trimethyl-5,7-dihydroxy-2,3-dihydrobenzofuran (1), together with gentisic acid (2), and their structures were determined on the basis of spectroscopic data. In the 1,1-diphenyl-picryl-hydrazyl (DPPH) assay system, compounds 1 and 2 showed free radical scavenging activity with IC(20) values of 10.39 and 4.26 microM, respectively.

Topics: Antioxidants; Benzofurans; Biphenyl Compounds; Chromatography, High Pressure Liquid; Free Radical Scavengers; Inhibitory Concentration 50; Molecular Structure; Nuclear Magnetic Resonance, Biomolecular; Penicillium; Picrates; Taiwan

Preparative-scale incubations with Nocardia sp. NRRL 5646 were conducted to produce new derivatives of the abietane diterpene chemoprotectant and antioxidant carnosic acid (1). Reductive biotransformation of the C-20 carboxylic acid functional group followed by biological methylation at the C-11 phenol afforded 4. Oxidative cyclization of 1 to carnosol 5 followed by dihydroxylation at the isopropyl moiety afforded 6. Metabolites 4 and 6 are new carnosic acid derivatives whose structures were confirmed by mass spectrometry and NMR spectroscopic analysis. The radical quenching properties of 4-6 using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) free-radical-scavenging assay showed activities similar to that of mixed tocopherols and carnosic acid.

Topics: Abietanes; Antioxidants; Biphenyl Compounds; Cyclization; Diterpenes; Free Radical Scavengers; Mass Spectrometry; Methylation; Molecular Structure; Nocardia; Nuclear Magnetic Resonance, Biomolecular; Oxidation-Reduction; Picrates; Plant Extracts; Rosmarinus; Structure-Activity Relationship

Alkanoyl-6-O-ascorbic acid esters are easily obtained from vitamin C, and produce self-assembled aggregates in water solutions, with an inner hydrophobic pool surrounded by an external hydrophilic shell. Compared to ascorbic acid, their solubility in oils and fats is greatly enhanced, while the peculiar antioxidant activity is retained in the polar head groups of such surfactants. In virtue of their amphiphilic nature, ascorbic acid-based supramolecular systems can dissolve relevant amounts of hydrophobic, poorly water soluble chemicals such as drugs, vitamins, and so on, and at the same time they provide a suitable shield against oxidative deterioration of valuable materials. In this article we report our study on the self-assembling properties of octanoyl-6-O-ascorbic acid in water, and on the solubilization of some lipophilic molecules in its dispersions.

Topics: Antioxidants; Ascorbic Acid; Biphenyl Compounds; Chemical Phenomena; Chemistry, Physical; Electric Conductivity; Light; Micelles; Oxidants; Pharmaceutical Preparations; Picrates; Refractometry; Scattering, Radiation; Solubility; Solvents; Spectrophotometry, Ultraviolet; Surface Tension; Viscosity

Squalene was identified by gas chromatography-mass spectrometry and high-performance liquid chromatography (HPLC) spiking analyses in the supercritical CO(2) extracts of freeze-dried abscisic leaves of Terminalia catappa L. When the freeze-dried abscisic, senescent, mature, and immature leaves and seeds were subjected to supercritical CO(2) extraction at 40 degrees C and 3000 psi and HPLC quantitation, squalene contents were 12.29, 2.42, 1.75, 0.9, and 0% in the extracts and corresponding to 1499, 451, 210, 65, and 0 microg/g in the freeze-dried sample, respectively. When the extracts were applied for antioxidative characterization by supplementation in an iron/ascorbate system with linoleic acid and in a pork fat storage system for inhibition of conjugated diene hydroperoxide (CDHP) formation or in a free radical scavenging system with 1,1-diphenyl-2-picryl-hydrazyl (DPPH), the extracts of leaves exhibited potent antioxidative and DPPH scavenging activities and increased with an increase of leaf maturity. However, the seed extracts only exhibited potent inhibition of CDHP formation and very low DPPH scavenging activity.

Topics: Animals; Antioxidants; Ascorbic Acid; Biphenyl Compounds; Chromatography, High Pressure Liquid; Chromatography, Supercritical Fluid; Free Radical Scavengers; Freeze Drying; Gas Chromatography-Mass Spectrometry; Hydrogen Peroxide; Iron; Linoleic Acid; Lipid Peroxidation; Picrates; Plant Extracts; Plant Leaves; Seeds; Squalene; Swine; Terminalia

The decarboxylated noradrenaline metabolite 3,4-dihydroxymandelic acid [DHMA, 2-(3,4-dihydroxyphenyl)-2-hydroxyacetic acid] occurs in different mammalian tissues, especially in the heart. To elucidate the physiological function of DHMA, the antioxidative and radical scavenging activity was determined by physicochemical and cell-based test systems. In the 2,2-diphenyl-1-picrylhydrazyl assay it shows a 4-fold higher radical scavenging activity compared to the standard antioxidants ascorbic acid, tocopherol, and butylated hydroxytoluene. DHMA is also a very potent superoxide radical scavenger and shows a 5-fold smaller IC(50) value compared to standard ascorbic acid. Again, in most cases the antioxidative power of DHMA against bulk lipid oxidation determined by accelerated autoxidation of oils is much higher than for the standard antioxidants. In soybean oil and squalene a DHMA/alpha-tocopherol mixture (1:1 w/w) shows a synergistic effect. Last but not least, 0.001 and 0.0005% levels of DHMA protect human primary fibroblasts against H(2)O(2)-induced oxidative stress as determined by the 2',7'-dichlorofluorescein assay.

Topics: alpha-Tocopherol; Antioxidants; Ascorbic Acid; Biphenyl Compounds; Butylated Hydroxytoluene; Chemical Phenomena; Chemistry, Physical; Drug Synergism; Fibroblasts; Free Radical Scavengers; Humans; Hydrogen Peroxide; Lipid Peroxidation; Mandelic Acids; Oxidative Stress; Picrates; Soybean Oil; Squalene; Superoxides; Tocopherols

Stoichiometric evaluation of the radical scavenging activity of O-substituted derivatives at the C-2 position of ascorbic acid (AA) was conducted. Their reaction with a stable radical, 1,1-diphenyl-2-picrylhydrazyl (DPPH), under an acidic condition was assessed by the colorimetric method. 2-O-alpha-D-Glucopyranosyl-L-ascorbic acid (AA-2G) and a series of 6-O-acyl-2-O-alpha-D-glucopyranosyl-L-ascorbic acids (6-Acyl-AA-2G) had long-term radical scavenging activity against DPPH. The reaction of AA-2G or 6-Acyl-AA-2G with DPPH was very slow when compared with AA. However, one molecule of these derivatives consumed approximately three molecules of DPPH radicals at the end of the experiment (2 h). In contrast, one molecule of AA scavenged two molecules of DPPH radicals, and the reaction ended in the short time (<10 min). The quantity of radicals quenched by AA-2G and 6-Acyl-AA-2G was superior to that of AA in a long-term reaction.

Topics: Ascorbic Acid; Biphenyl Compounds; Free Radical Scavengers; Picrates

The antioxidant and prooxidant activities of flavonoids belonging to several classes were studied to establish their structure-activity relationships against different oxidants. Special attention was paid to the flavonoids quercetin (flavone), taxifolin (flavanone) and catechin (flavanol), which possess different basic structures but the same hydroxylation pattern (3,5,7,3'4'-OH). It was found that these three flavonoids exhibited comparable antioxidant activities against different oxidants leading to the conclusion that the presence of ortho-catechol group (3',4'-OH) in the B-ring is determinant for a high antioxidant capacity. The flavone kaempferol (3,5,7,4'-OH), however, in spite of bearing no catechol group, also presents a high antioxidant activity against some oxidants. This fact can be attributed to the presence of both 2,3-double bond and the 3-hydroxyl group, meaning that the basic structure of flavonoids becomes important when the antioxidant activity of B-ring is small.

Topics: Amidines; Antioxidants; Ascorbic Acid; Biphenyl Compounds; Catechin; Edetic Acid; Flavonoids; Flavonols; Free Radicals; Iron; Kaempferols; Liposomes; Metmyoglobin; Picrates; Quercetin; Structure-Activity Relationship

Hemidesmus indicus R. Br. (Asclepiadaceae) is a well known drug in Ayurveda system of medicine. In the present study, antioxidant activity of methanolic extract of H. indicus root bark was evaluated in several in vitro and ex vivo models. Further, preliminary phytochemical analysis and TLC fingerprint profile of the extract was established to characterize the extract which showed antioxidant properties. The in vitro and ex vivo antioxidant potential of root bark of H. indicus was evaluated in different systems viz. radical scavenging activity by DPPH reduction, superoxide radical scavenging activity in riboflavin/light/NBT system, nitric oxide (NO) radical scavenging activity in sodium nitroprusside/Greiss reagent system and inhibition of lipid peroxidation induced by iron-ADP-ascorbate in liver homogenate and phenylhydrazine induced haemolysis in erythrocyte membrane stabilization study. The extract was found to have different levels of antioxidant properties in the models tested. In scavenging DPPH and superoxide radicals, its activity was intense (EC50 = 18.87 and 19.9 microg/ml respectively) while in scavenging NO radical, it was moderate. It also inhibited lipid peroxidation of liver homogenate (EC50 = 43.8 microg/ml) and the haemolysis induced by phenylhydrazine (EC50 = 9.74 microg/ml) confirming the membrane stabilization activity. The free radical scavenging property may be one of the mechanisms by which this drug is effective in several free radical mediated disease conditions.

Topics: alpha-Tocopherol; Animals; Antioxidants; Apocynaceae; Ascorbic Acid; Biphenyl Compounds; Chromatography, Thin Layer; Curcumin; Erythrocyte Membrane; Free Radical Scavengers; Hemolysis; Lipid Peroxidation; Liver; Medicine, Ayurvedic; Nitric Oxide; Oxidants; Phenylhydrazines; Picrates; Plant Bark; Plant Extracts; Plant Roots; Pyrogallol; Rats; Superoxides

To express the antioxidant capacity of plant foods in a more familiar and easily understood manner (equivalent to vitamin C mg/100 g), two stable radical species, ABTS(*)(-) and DPPH(*), commonly used for antioxidant activity measurements, were employed independently to evaluate their efficacies using apple polyphenolic extracts and seven polyphenolic standards including synthetic Trolox. Their antioxidant activities were expressed as vitamin C equivalent antioxidant capacity (VCEAC) in mg/100 g apple or mg/100 mL of the reference chemical compounds in 10 and 30 min using the ABTS(*)(-) and DPPH(*) scavenging assays, respectively. The antioxidant capacity of Gala apples and seven phenolic standards, determined by both ABTS(*)(-) and DPPH(*) scavenging assays, showed a dose-response of the first-order. Fresh Gala apples had a VCEAC of 205.4 +/- 5.6 mg/100 g using the ABTS assay, and the relative VCEACs of phenolic standards were as follows: gallic acid > quercetin > epicatechin > catechin > vitamin C > rutin > chlorogenic acid > Trolox. With the DPPH radical assay, the VCEAC of fresh Gala apples was 136.0 +/- 6.6 mg/100 g, and the relative VCEACs of seven phenolic standards were, in decreasing order, as follows: gallic acid > quercetin > epicatechin > catechin > or = vitamin C > Trolox > rutin > chlorogenic acid. Because the ABTS assay can be used in both organic and aqueous solvent systems, employs a specific absorbance at a wavelength remote from the visible region, and requires a short reaction time, it is a more desirable method than the DPPH assay. Therefore, it is recommended that antioxidant capacity be expressed as vitamin C mg/100 g equivalent (VCEAC) using the ABTS assay.

Topics: Antioxidants; Ascorbic Acid; Benzothiazoles; Biphenyl Compounds; Catechin; Chlorogenic Acid; Chromans; Free Radical Scavengers; Free Radicals; Gallic Acid; Kinetics; Malus; Oxidation-Reduction; Phenols; Picrates; Plant Extracts; Plants, Edible; Quercetin; Rutin; Sulfonic Acids

Four spectrophotometric methods of determination of antioxidant capacity: a method based on the scavenging of the l,1-diphenyl-2-picrylhydrazyl (DPPH) free radical, the "ferric-reducing ability of plasma" (FRAP), a method based on reduction of the 2.2'-azinobis (3-ethylbenzthiazolinesulfonate) free radical (ABTS.+) and a kinetic method based on the oxidation of dihydro-2,7-dichlorofluorescein by 2,2'-azobis(2-amidopropane) (ABAP) were compared with respect to standard antioxidants (ascorbate, glutathione, Trolox and urate) and human blood plasma. Various reactivities of standard antioxidants in different tests were found. glutathione showing a low reactivity in the FRAP assay. Kinetic measurements show that the reduction of indicators, especially by blood plasma, may not be complete at recommended times of the assays and the time of measurement is an important parameter when comparing the results.

Topics: Adult; Amidines; Antioxidants; Ascorbic Acid; Benzothiazoles; Biphenyl Compounds; Chemistry, Clinical; Female; Glutathione; Humans; Kinetics; Male; Middle Aged; Oxidative Stress; Picrates; Plasma; Spectrophotometry; Sulfonic Acids; Uric Acid

The aleurone layer of Oryza sativa cv. Heugjinmi yielded a new quinolone alkaloid, 4-carbomethoxy-6-hydroxy-2-quinolone (1), showing moderate antioxidative activity in a 1,1-diphenyl-2-picrylhydrazyl free-radical scavenging assay. Physical and spectroscopic evidence has determined the structure of the compound.

Topics: Alkaloids; Anthocyanins; Antioxidants; Bepridil; Biphenyl Compounds; Chromatography; Free Radical Scavengers; Inhibitory Concentration 50; Korea; Mass Spectrometry; Molecular Structure; Nuclear Magnetic Resonance, Biomolecular; Oryza; Picrates; Quinolones; Spectrophotometry, Infrared; Spectrophotometry, Ultraviolet

The radical scavenging activity of the stable derivatives, which are O-substituted at the C-2 position of ascorbic acid (AA), against 1,1-diphenyl-2-picrylhydrazyl (DPPH) was evaluated in buffer under different pH conditions, and compared with those of AA and alpha-tocopherol. AA was shown to have 50% radical scavenging ability (EC50) at a concentration of 2.2 x 10(-5) M against 0.1 mM DPPH in 60% ethanol. Ascorbyl 6-palmitate, a lipophilic AA derivative which has a free endiol group and is therefore unstable, also showed potent radical scavenging activity with EC50 of 2.9 x 10(-5) M. A typical lipophilic antioxidant, alpha-tocopherol gave a similar EC50 value as that of AA. In contrast, ascorbyl 2,6-dipalmitate, AA 2-phosphate and AA 2-sulfate exhibited negligible scavenging activity. On the other hand, 2-O-alpha-D-glucopyranosyl-L-ascorbic acid (AA-2G) and a series of 6-O-acyl-2-O-alpha-D-glucopyranosyl-L-ascorbic acids (6-Acyl-AA-2G) themselves exhibited the radical scavenging activity of EC50: 6.1 x 10(-5) M and 4.4 x 10(-5)-5.9 x 10(-5) M, respectively, although their activities were lower than that of AA. Among 6-Acyl-AA-2G derivatives, the EC50 values tended to decrease with increasing length of their acyl carbon group. Increasing pH of the buffer resulted in decrease in the scavenging activity of all compounds tested as expected. We speculate that the difference in the radical scavenging activity of derivatives O-substituted at the C-2 position of AA may be ascribed to the linkage type of the substituent group to the endiol-lactone resonance system and the degree of dissociation of the C-3 proton.

Topics: Ascorbic Acid; Bepridil; Biphenyl Compounds; Free Radical Scavengers; Hydrolysis; Picrates; Vitamin E

DPPH (alpha,alpha-diphenyl-beta-picryl hydrazyl) (CAS 217-591-8), a stable free radical can be used to determine the antioxidant activity (AOA) of some drugs. In the present study the DPPH method was used for the first time to test AOA of dapsone (CAS 80-08-0), clofazimine (CAS 2030-63-9) and rifampicin (CAS 13282-42-1) in vitro and deproteinated blood method. Ascorbic acid (CAS 50-81-7) was used as a control in the study, which showed concentration-dependent antioxidant activity. Rifampicin showed a per se effect but it showed concentration dependent decrease in the DPPH absorbance. Ascorbic acid, dapsone and rifampicin showed DPPH scavenging activity both in vitro and deproteinated blood method. Clofazimine did not have any influence on DPPH. This method may be extended to different drugs for testing their AOA in biological fluids.

Topics: Adult; Antioxidants; Ascorbic Acid; Bepridil; Biphenyl Compounds; Clofazimine; Dapsone; Humans; Leprostatic Agents; Male; Oxidation-Reduction; Picrates; Rifampin; Spectrophotometry, Ultraviolet

As a part of our studies on the metabolism of natural compounds, gallic acid was orally administered to rats. The urinary metabolites were analyzed by high-performance liquid chromatography, and their structures were determined to be pyrogallol (M1), pyrogallol-1-O-beta-D-glucuronide (M2), 4-O-methylgallic acid-3-O-sulfate (M3), 2-O-methylpyrogallol-1-O-beta-D-glucuronide (M4), 2-O-methylpyrogallol (M5), 4-O-methylgallic acid (M6), and unchanged gallic acid on the basis of chemical and spectral data. The radical scavenging effects of gallic acid and its urinary metabolites were evaluated using 1,1-diphenyl-2-picrylhydrazyl radical.

Topics: Animals; Bepridil; Biphenyl Compounds; Chromatography, High Pressure Liquid; Free Radical Scavengers; Gallic Acid; Male; Molecular Structure; Picrates; Rats

Fenretinide, N-(4-hydroxyphenyl)retinamide (4-HPR), is a cancer chemopreventive and antiproliferative agent whose mechanism of action is unknown. 4-HPR is a potent inducer of apoptosis in HL60 human leukemia cells which generates intracellular reactive oxygen species. The structural similarity of retinoic acid (RA), 4-HPR, and alpha-tocopherol (vitamin E) led us to investigate whether 4-HPR exhibits antioxidant activity. It was found that 4-HPR scavenged alpha,alpha-diphenyl-beta-picrylhydrazyl (DPPH) radicals in a 1:1 ratio in contrast to vitamin E, where a 1:2 ratio relative to DPPH radicals was observed. In addition, linoleic acid peroxidation initiated by hydroxyl radicals was decreased by 4-HPR to the same extent as by vitamin E. Furthermore, lipid peroxidation in rat liver microsomes was reduced by 4-HPR to a greater extent than by vitamin E. Based on these results, 4-HPR appears to be an effective antioxidant that may have clinical utility for diseases treated with vitamin E.

Topics: Animals; Antineoplastic Agents; Antioxidants; Ascorbic Acid; Bepridil; Biphenyl Compounds; Fenretinide; Free Radical Scavengers; Free Radicals; Humans; Hydroxyl Radical; In Vitro Techniques; Linoleic Acid; Lipid Peroxidation; Male; Microsomes, Liver; Picrates; Rats; Rats, Sprague-Dawley; Reactive Oxygen Species; Retinoids; Vitamin E

To define the molecular mechanism(s) of resveratrol inhibition of lipid peroxidation we have utilized model systems that allow us to study the different reactions involved in this complex process. Resveratrol proved (a) to inhibit more efficiently than either Trolox or ascorbate the Fe2+ catalyzed lipid hydroperoxide-dependent peroxidation of sonicated phosphatidylcholine liposomes; (b) to be less effective than Trolox in inhibiting lipid peroxidation initiated by the water soluble AAPH peroxyl radicals; (c) when exogenously added to liposomes, to be more potent than alpha-tocopherol and Trolox, in the inhibition of peroxidation initiated by the lipid soluble AMVN peroxyl radicals; (d) when incorporated within liposomes, to be a less potent chain-breaking antioxidant than alpha-tocopherol; (e) to be a weaker antiradical than alpha-tocopherol in the reduction of the stable radical DPPH*. Resveratrol reduced Fe3+ but its reduction rate was much slower than that observed in the presence of either ascorbate or Trolox. However, at the concentration inhibiting iron catalyzed lipid peroxidation, resveratrol did not significantly reduce Fe3+, contrary to ascorbate. In their complex, our data indicate that resveratrol inhibits lipid peroxidation mainly by scavenging lipid peroxyl radicals within the membrane, like alpha-tocopherol. Although it is less effective, its capacity of spontaneously entering the lipid environment confers on it great antioxidant potential.

Topics: Antioxidants; Ascorbic Acid; Bepridil; Biphenyl Compounds; Chromans; Free Radical Scavengers; Free Radicals; In Vitro Techniques; Iron; Lipid Peroxidation; Liposomes; Picrates; Resveratrol; Stilbenes; Vitamin E

Reactive oxygen species are thought to induce cellular damage and to play a pathological role in several human diseases. Tetradecylthioacetic acid (TTA) was previously reported to prevent the oxidative modification of low-density lipoprotein (LDL) particles and to act as an antioxidant. In this study we present a new fatty acid analogue, namely tetradecylselenoacetic acid (TSA), in which the sulfur atom of TTA is replaced by a selenium atom. TSA was more potent than TTA in increasing the lag time before the onset of LDL oxidation and this effect was dose dependent. TTA and TSA were shown to reduce the iron-ascorbate-induced microsomal lipid peroxidation, TSA being more efficient than TTA. TTA and TSA, in the presence of iron, interacted with the superoxide radical as assessed by direct and indirect testing methods. TSA like TTA failed to scavenge 1.1-diphenyl-2-picrylhydrazyl radicals. TSA bound copper ions as shown by the wavelength spectra measurement. These results suggest that TTA and TSA exert their antioxidant capacity by interaction with copper or iron ions in radical scavenging, TSA being more potent than TTA. Nevertheless, a chelating effect resulting in chemically inactive metal ions cannot be excluded.

Topics: Animals; Antioxidants; Ascorbic Acid; Bepridil; Biphenyl Compounds; Copper; Cytochrome c Group; Electrophoresis, Agar Gel; Fatty Acids; Ferrous Compounds; Free Radical Scavengers; Iron; Lipid Peroxidation; Lipoproteins, LDL; Male; Microsomes, Liver; Organometallic Compounds; Palmitic Acid; Picrates; Rats; Rats, Wistar; Sulfides; Superoxides

Novel hybrid L-ascorbic acid (vitamin C) derivatives with other biologically active substances, 5-hydroxy-2-hydroxymethyl-beta-pyrone (kojic acid) and alpha-tocopherol (vitamin E), linked at the C-2 or C-3 hydroxyl group were synthesized, and their thermal stability and inhibitory effects on tyrosinase activity, active oxygen species (AOS), and free radicals were estimated in vitro. It was found that a hydrophilic derivative, 2-O-(5-hydroxy-4H-pyran-4-one-2-methyl)-L-ascorbic acid (1), exhibited good thermal stability and inhibitory activities against tyrosinase catalyzed melanin formation, AOS, and free radicals compared to vitamin C and its conventional derivatives (such as the 2-phosphate 6-stearate and 2.6-dipalmitate, and 2-O-octadecylascorbic acid), as well as vitamin E, kojic acid, and arbutin. It is apparent that 1 has the biological properties of vitamin C and kojic acid, and acts synergistically. The hydroxyl groups at the C-3 position of the vitamin C moiety and the C-5 position of the kojic acid moiety are critical for the biological activities. We consider that the kojic acid moiety of 1 counterbalances the diminution of the biological activity due to shielding of the biologically important C-2 hydroxyl group of the vitamin C moiety. In addition, the thermal stability was significantly improved relative to not only vitamin C but also kojic acid. Further, a lipophilic derivative, 3-O-[(alpha-tocopheryloxy)-2-hydroxypropyl]-L-ascorbic acid, 2, was far more stable than vitamin C and its typical lipophilic derivatives. Compound 2 exhibited almost the same inhibitory activities against tyrosinase-catalyzed melanin formation, AOS, and free radicals as typical lipophilic derivatives, although these biological activities of 2 were lower than those of vitamin C.

Topics: Ascorbic Acid; Bepridil; Biphenyl Compounds; Free Radicals; Melanins; Monophenol Monooxygenase; Oxidation-Reduction; Photochemistry; Picrates; Pyrones; Reactive Oxygen Species; Superoxides; Temperature; Tyrosine; Vitamin E

A novel series of hybrid L-ascorbic acid (vitamin C) phosphodiesters linked at the C-2 hydroxyl group with other biologically active substances, namely myo-inositol, arbutin, 4-hydroxy-L-proline, and glycolic acid were synthesized, and their thermal stability and reducing activity against free radicals were estimated in vitro. All of the phosphodiesters exhibited high thermal stabilities; however, their antioxidant activities in vitro were generally lower than that of vitamin C.

Topics: Antioxidants; Arbutin; Ascorbic Acid; Bepridil; Biphenyl Compounds; Esters; Free Radicals; Glycolates; Hydroxyproline; Inositol; Magnetic Resonance Spectroscopy; Molecular Structure; Oxidation-Reduction; Phosphorylation; Picrates; Temperature

Oren-Gedoku-To (TJ-15) inhibited enzymatically (NADPH or CumOOH) and non-enzymatically (Fe-ascorbate) induced lipid peroxidation in rat liver microsomes as assessed by TBA-reactive product accumulation. Toki-Shakuyaku-San (TJ-23) had little effect on either system. The protective effect of TJ-15 against lipid peroxidation was not dependent upon the presence of microsomal drug-metabolizing activity and could not be fully accounted for by its action on microsomal electron transfer, as evaluated by studying the kinetics of cytochrome c reduction. Both TJ-15 and TJ-23 reduced the stable free radical 1,1-diphenyl-2-picrylhydrazyl (DPPH), indicating their free radical scavenging ability. The reactivity of TJ-15 was comparable with that of standard ascorbate, while the activity of TJ-23 was approximately 10 times lower. In a free solution TJ-15 and TJ-23 effectively scavenged OH* radicals, as indicated by the inhibition of ethylene production from 2-keto-4-methiolbutyric acid (KMBA), and O2*- anion radicals, as assessed by the inhibitory effect on the rate of nitro blue tetrazolium (NBT) reduction by the O2*- generating system xanthine/xanthine oxidase.

Topics: Animals; Ascorbic Acid; Biphenyl Compounds; Drugs, Chinese Herbal; Electron Transport; Free Radical Scavengers; Hydroxyl Radical; In Vitro Techniques; Iron; Lipid Peroxidation; Male; Microsomes, Liver; NADPH-Ferrihemoprotein Reductase; Oxidants; Oxidative Stress; Picrates; Rats; Rats, Wistar; Superoxides; Xanthine Oxidase

The antioxidant action of thiopalmitic acid (SH-Pal) was studied in a lipid peroxidation system using microsomes from rat liver. The Fe(II)/ascorbic acid (AsA)-induced lipid peroxidation, as measured by the amount of thiobarbituric acid-reactive substances (TBA-RS), was progressively inhibited by the addition of increasing amounts of SH-Pal. The inhibitory effect of SH-Pal in this experimental system was greater than that of alpha-tocopherol, glutathione (GSH) and palmitic acid. The antioxidative effect was abolished gradually by the addition of increasing amounts of N-ethylmaleimide to the system. Similarly, microsomal lipid peroxidation induced by Fe(III)-ADP/NADPH or CCl4/NADPH was inhibited in a dose-dependent fashion by the addition of SH-Pal. Moreover, SH-Pal was able to reduce 1,1-diphenyl-2-picrylhydrazyl (DPPH). The alpha-tocopherol content of the microsomal lipid peroxidation system decreased rapidly when no SH-Pal was present. However, upon adding SH-Pal (90 microM), the decrease in the alpha-tocopherol content of the assay system was markedly reduced. These findings indicate that SH-Pal acts as an antioxidant and free radical scavenger in lipid peroxidation carried out by rat liver microsomes.

Topics: Adenosine Diphosphate; Animals; Antioxidants; Ascorbic Acid; Bepridil; Biphenyl Compounds; Carbon Tetrachloride; Free Radical Scavengers; In Vitro Techniques; Lipid Peroxidation; Male; Microsomes, Liver; Oxidation-Reduction; Palmitic Acids; Picrates; Rats; Rats, Wistar; Thiobarbituric Acid Reactive Substances; Vitamin E

Topics: Animals; Antioxidants; Ascorbic Acid; Biphenyl Compounds; Brain; Depression, Chemical; Dogs; Free Radicals; Hydrazines; Lipid Peroxidation; Picrates; Reperfusion Injury

Topics: Ascorbic Acid; Biomechanical Phenomena; Biphenyl Compounds; Drugs, Chinese Herbal; Electron Spin Resonance Spectroscopy; Free Radicals; Humans; Hydrazines; Picrates; Plant Extracts; Seizures; Vitamin E

The role of radical scavenging action in cerebral protective effect of drugs was investigated in vitro. Incubation of rat brain mitochondrial suspension with ascorbic acid and Fe2+ resulted in the formation of malondialdehyde and a decrease in the turbidity of the suspension, indicating that the mitochondria were peroxidatively disintegrated. Nizofenone at 10 micro M or more inhibited the peroxidative disintegration of mitochondria, and complete inhibition was observed at 100-200 micro M. The action of nizofenone was also ascertained by experiments with rat liver mitochondria. The anti-peroxidative activity of nizofenone was estimated to be approximately equivalent to that of alpha-tocopherol, and this property was unique. Among the cerebral protective drugs tested, thiopental was only slightly efficient, and pentobarbital, phenobarbital, and dimethyl sulfoxide had no effect. In addition, nizofenone was found to scavenge a stable free radical, diphenyl-p-picrylhydrazyl, but the barbiturates did not. These findings suggest that there is no intimate relationship between cerebral protective effect and free radical scavenging action.

Topics: Animals; Ascorbic Acid; Biphenyl Compounds; Brain; Dimethyl Sulfoxide; Hydrazines; Imidazoles; Indicators and Reagents; Lipid Peroxides; Male; Mitochondria; Mitochondria, Liver; Pentobarbital; Phenobarbital; Picrates; Rats; Rats, Inbred Strains