1-1-diphenyl-2-picrylhydrazyl and n-hexane

The essential oil extracted from Desfontaine's rupturewort, Herniaria fontanesii J. Gay subsp. fontanesii growing wildly in Tunisia, was analyzed using GC and GC-MS techniques. The free radical scavenging capacity and total phenol contents of three crude extracts having different polarities (n-hexane, ethyl acetate and methanol) were examined. Thus, a total of 35 constituents were identified in the Desfontaine's rupturewort essential oil representing 89.8% of the whole constituents. The oil was dominated by hexadecanoic acid, caryophyllene oxide, terpin-4-ol, khusimone and trans-sabinene hydrate. The total phenolic contents ranged from 16.91 to 92.27 mg of gallic acid/g of dry weight and they were found to be significantly higher in methanol than in polar ethyl acetate and hexane extracts. Correlations were observed between the phenolic contents and the antioxidant properties. Thus, the antioxidant activity of the methanol extract was superior to that of all samples tested (IC50 = 0.21 ± 0.04 mg/mL).

Topics: Acetates; Bicyclic Monoterpenes; Biphenyl Compounds; Caryophyllaceae; Free Radical Scavengers; Gallic Acid; Gas Chromatography-Mass Spectrometry; Hexanes; Methanol; Monoterpenes; Oils, Volatile; Palmitic Acid; Picrates; Plant Components, Aerial; Plant Extracts; Polycyclic Sesquiterpenes; Sesquiterpenes; Solvents; Terpenes; Tunisia

An efficient method for the rapid extraction, separation and purification of bioactive lignans, arctiin and arctigenin, from Fructus arctii by microwave-assisted extraction coupled with high-speed countercurrent chromatography was developed. The optimal extraction conditions of arctiin and arctigenin were evaluated by orthogonal array. Arctigenin could be converted from arctiin by hydrochloric acid hydrolysis. The separations were performed at a preparative scale with two-phase solvents composed of ethyl acetate-ethanol-water (5 : 1 : 5, v/v/v) for arctiin, and n-hexane-ethyl acetate-ethanol-water (4 : 4 : 3 : 4, v/v/v/v) for arctigenin. From 500 mg of crude extract sample, 122.3 mg of arctiin and 45.7 mg of arctigenin were obtained with the purity of 98.46 and 96.57%, and the recovery of 94.3 and 81.6%, respectively. Their structures were determined by comparison with the high-performance liquid chromatography retention time of standard substance as well as UV, FT-IR, electrospray ion source (ESI)-MS, (1)H-NMR and (13)C-NMR spectrum. According to the antioxidant activity assay, arctigenin had stronger 1,1-diphenyl-2-picrylhydrazyl free radicals scavenging activity.

Topics: Acetates; Arctium; Biphenyl Compounds; Chromatography, High Pressure Liquid; Countercurrent Distribution; Ethanol; Free Radical Scavengers; Furans; Glucosides; Hexanes; Hydrochloric Acid; Hydrolysis; Lignans; Liquid-Liquid Extraction; Microwaves; Picrates; Plant Extracts; Solvents; Water

Chemical investigation of Codonopsis ovata resulted in the isolation and identification of β-sitosterol-3-O-glycoside, luteolin, apigenin, gentiacaulein, swertiaperenine, β-sitosterol, taraxeryl-3-acetate, and 3β-acetoxyoleanane-12-one. A rapid, precise, sensitive and validated HPTLC method for simultaneous quantification of these natural products (NPs) was developed on silica-gel 60F254 plate using ternary solvent system, n-hexane:ethyl acetate:formic acid (10.5:3.5:0.43, v/v/v). Markers were quantified after post chromatographic derivatization with cerric ammonium sulfate reagent. The method was validated for accuracy, precision, LOD, LOQ and all calibration curves showed a good linear relationship (r>0.9924) within test range. Precision was evaluated by intra- and inter-day tests with RSDs <2.59%, accuracy validation recovery 92.43-99.50% with RSDs <1.00%. Apigenin was found major component (natural abundance: 1.103%) and β-sitosterol the least (0.0263%). The NPs displayed antioxidant activity with luteolin exhibiting maximum effect at 1μg/mL concentration (75.9% for DPPH and 43.7% for ABTS) and others at 10 and 25μg/mL, suggesting thereby their apparent potential use for the prevention of free radical induced diseases or as an additive element to food and pharmaceutical industry.

Topics: Acetates; Ammonium Sulfate; Benzothiazoles; Biphenyl Compounds; Calibration; Chromatography, Thin Layer; Codonopsis; Formates; Free Radical Scavengers; Hexanes; Limit of Detection; Linear Models; Phytotherapy; Picrates; Plant Extracts; Plants, Medicinal; Reference Standards; Reproducibility of Results; Silica Gel; Solvents; Sulfonic Acids

Based on the ethnomedicinal uses and the effective outcomes of natural products in various diseases, this study was designed to evaluate Isodon rugosus as possible remedy in oxidative stress, alzheimer's and other neurodegenerative diseases. Acetylecholinestrase (AChE) and butyrylcholinesterase (BChE) inhibitory activities of crude methanolic extract (Ir.Cr), resultant fractions (n-hexane (Ir.Hex), chloroform (Ir.Cf), ethyl acetate (Ir.EtAc), aqueous (Ir.Aq)), flavonoids (Ir.Flv) and crude saponins (Ir.Sp) of I. rugosus were investigated using Ellman's spectrophotometric method. Antioxidant potential of I. rugosus was determined using DPPH, H2O2 and ABTS free radicals scavenging assays. Total phenolic and flavonoids contents of plant extracts were determined and expressed in mg GAE/g dry weight and mg RTE/g of dry sample respectively.. Among different fractions Ir.Flv and Ir.Cf exhibited highest inhibitory activity against AChE (87.44 ± 0.51, 83.73 ± 0.64%) and BChE (82.53 ± 0.71, 88.55 ± 0.77%) enzymes at 1 mg/ml with IC50 values of 45, 50 for AChE and 40, 70 μg/ml for BChE respectively. Activity of these fractions were comparable to galanthamine causing 96.00 ± 0.30 and 88.61 ± 0.43% inhibition of AChE and BChE at 1 mg/ml concentration with IC50 values of 20 and 47 μg/ml respectively. In antioxidant assays, Ir.Flv, Ir.Cf, and Ir.EtAc demonstrated highest radicals scavenging activities in DPPH and H2O2 assays which were comparable to ascorbic acid. Ir.Flv was found most potent with IC50 of 19 and 24 μg/ml against DPPH and H2O2 radicals respectively. Whereas antioxidant activates of plant samples against ABTS free radicals was moderate. Ir.Cf, Ir.EtAc and Ir.Cr showed high phenolic and flavonoid contents and concentrations of these compounds in different fractions correlated well to their antioxidant and anticholinestrase activities.. It may be inferred from the current investigations that the Ir.Sp, Ir.Flv and various fractions of I. rugosus are good sources of anticholinesterase and antioxidant compounds. Different fractions can be subjected to activity guided isolation of bioactive compounds effective in neurological disorders.

Topics: Acetates; Acetylcholinesterase; Antioxidants; Benzothiazoles; Biphenyl Compounds; Butyrylcholinesterase; Chloroform; Cholinesterase Inhibitors; Complex Mixtures; Flavonoids; Free Radical Scavengers; Free Radicals; Hexanes; Hydrogen Peroxide; Inhibitory Concentration 50; Isodon; Medicine, Traditional; Methanol; Oxidative Stress; Picrates; Plant Components, Aerial; Plant Extracts; Saponins; Spectrophotometry; Sulfonic Acids

The present study evaluates the influence of drying and cooking processes on the health properties of two bell Capsicum annuum L. cultivars Roggiano and Senise compared with fresh peppers. The content of phytochemicals decreased in the order fresh>dried>dried frying processes. HPLC analysis was applied to quantify five flavonoids from peppers. Apigenin was identified as main constituent. Its content was affected by drying and dried frying processes. The antioxidant activity was evaluated by DPPH, ABTS, β-carotene bleaching test and Fe-chelating activity assay. A comparable radical scavenging activity was observed for both cultivars. Interestingly, frying process did not influenced this property. Roggiano peppers exhibited the highest antioxidant activity using β-carotene bleaching test with IC(50) values of 38.1 and 24.9 μg/mL for total extract and n-hexane fraction, respectively. GC-MS analysis of lipophilic fraction revealed the presence of fatty acids and vitamin E as major components. In the inhibition of the carbohydrate-hydrolyzing enzymes fresh Senise peppers exerted the strongest activity against α-amylase with an IC(50) value of 55.3 μg/mL. Our results indicate that C. annuum cultivars Roggiano and Senise have an interestingly potential health benefits not influenced by processes that are used before consumption.

Topics: alpha-Amylases; alpha-Glucosidases; Antioxidants; Benzothiazoles; beta Carotene; Biphenyl Compounds; Capsicum; Chelating Agents; Flavonoids; Food Handling; Fruit; Glycoside Hydrolase Inhibitors; Hexanes; Hypoglycemic Agents; Inhibitory Concentration 50; Iron; Phenols; Picrates; Sulfonic Acids

TLC-DPPH(•) test belongs to a group of frequently performed assays aimed at detection of compounds with desired activity (effect directed analysis). Despite its popularity a standard procedure has not been elaborated so far causing difficulties in comparing results obtained in different laboratories. Thus the aim of the presented research was an approach to develop a standardized procedure for assessing free radical scavenging properties of plant polyphenols. It was observed that specifically positive adsorbent (silica gel) strengthened the observed result of radical-antioxidant reaction, while polar bonded stationary phase CN-silica weakened it. Based on the observed results it was concluded that the TLC-DPPH(•) assay should be preferably performed on the surface of non-specific adsorbents (e.g.: RP-18) with the use of n-hexane for DPPH(•) dissolution. It is also proposed to document the results every 5 min after staining, as they change in time.

Topics: Adsorption; Biphenyl Compounds; Calibration; Chromatography, Thin Layer; Free Radical Scavengers; Hexanes; Picrates; Polyphenols; Reference Standards; Silica Gel; Solvents; Surface Properties; Time Factors

Artemisia parviflora leaf extracts were evaluated for potential antimicrobial and antioxidant properties. Antimicrobial susceptibility assay was performed against ten standard reference bacterial strains. Antioxidant activity was analyzed using the ferric thiocyanate and 2, 2-Diphenyl-1-Picrylhydrazyl (DPPH) assays. Radical scavenging activity and total phenolic content were compared. Phytochemical analyses were performed to identify the major bioactive constitution of the plant extract.. Hexane, methanol and ethyl acetate extracts of A. parviflora leaves exhibited good activity against the microorganisms tested. The n-hexane extract of A. parviflora showed high inhibition of the growth of Pseudomonas aeruginosa, Escherichia coli and Shigella flexneri. Methanol extract showed strong radical scavenging and antioxidant activity, other extracts showed moderate antioxidant activity. The major derivatives present in the extracts are of terpenes, steroids, phenols, flavonoids, tannins and volatile oil.. The results obtained with n-hexane extract were particularly significant as it strongly inhibited the growth of P. aeruginosa, E. coli and S. flexneri. The major constituent of the n-hexane extract was identified as terpenes. Strong antioxidant activity could be observed with all the individual extracts. The antimicrobial and antioxidant property of the extracts were attributed to the secondary metabolites, terpenes and phenolic compounds present in A. parviflora and could be of considerable interest in the development of new drugs.

Topics: Anti-Bacterial Agents; Antioxidants; Artemisia; Biphenyl Compounds; Escherichia coli; Hexanes; Iron; Methanol; Microbial Sensitivity Tests; Phenols; Picrates; Plant Extracts; Plant Leaves; Pseudomonas aeruginosa; Shigella flexneri; Terpenes; Thiocyanates

A known furanocoumarin, 8-geranyloxy psoralen, was isolated from n-hexane extract of Prangos uloptera roots by the TLC method. Its structure was determined by comparison of the spectral data with the literature. Cytotoxic effects of the isolated compound were determined by MTT and Tripan blue assays. The antioxidant and antimicrobial potential of the compound were evaluated by DPPH assay and agar dilution method, respectively. The MTT assay results showed that 8-geranyloxy psoralen reduced cell viability of Hela and Mc-Coy cell lines with IC(50) values of 0.792 and 0.835 mM, respectively. Based on the Tripan blue assay, the compound has cytotoxic effects, with an IC(50) value of 1.26 mM for Mc-Coy cell line. The compound exhibited weak antioxidant potential, with an RC(50) value of 0.262 mg mL(-1) and high antimicrobial effects against Staphylococcus epidermidis and Candida kefyr.

Topics: Anti-Infective Agents; Antioxidants; Apiaceae; Biphenyl Compounds; Candida; Cell Line; Chromatography, Thin Layer; Furocoumarins; HeLa Cells; Hexanes; Humans; Picrates; Plant Extracts; Plant Roots; Staphylococcus epidermidis

Antioxidant properties of brown seaweed (Sargassum siliquastrum) extracts were evaluated using various antioxidant measurements, i.e., inhibitory effect on thiobarbituric acid-reactive substances (TBARS), 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging, metal chelating effect, reducing power effect, and total phenolic compounds. When the extraction solvents n-hexane, chloroform, ethanol, and water were compared, the water extract showed the highest yield in extracted mass. Total phenolic compounds were the highest in the ethanol extract, with 127.4 mg/g. The TBARS inhibition of chloroform and ethanol extracts at 10 mg/mL was 90.9% and 80.9%, respectively. DPPH radical scavenging capacity was more than 90% in all extracts at 1 mg/mL. The chloroform extract exhibited the highest metal ion chelating ability of 69.6% at 10 mg/mL. The reducing power was found to be the highest in the ethanol extract at 10 mg/mL, showing an effect similar to ascorbic acid. Thus, the ethanol extract of S. siliquastrum has potential as a natural antioxidant.

Topics: Antioxidants; Biphenyl Compounds; Chloroform; Ethanol; Hexanes; Iron Chelating Agents; Oxidation-Reduction; Phenols; Picrates; Sargassum; Solvents; Thiobarbituric Acid Reactive Substances; Water