1-1-diphenyl-2-picrylhydrazyl and 3-4-dihydroxyphenylethanol

Antioxidants have been the subject of intense research interest due to their numerous health benefits. In this work, a series of new conjugates of hydroxytyrosol and coumarin were synthesized and evaluated for their free radical scavenging, toxicity and antioxidant mechanism in vitro. The all target compounds 14a-t exhibited better radical scavenging activity than BHT, hydroxytyrosol, and coumarin in both DPPH radical and ABTS

Topics: Antioxidants; Apoptosis; Benzothiazoles; Biphenyl Compounds; Cell Line; Cell Survival; Coumarins; Dose-Response Relationship, Drug; Humans; Hydrogen Peroxide; Molecular Structure; Phenylethyl Alcohol; Picrates; Reactive Oxygen Species; Structure-Activity Relationship; Sulfonic Acids

Context Although olive mill wastewater (OMWW) is a good source of bioactive phenolic compounds, disposing OMWW is a serious environmental challenge. Production of wine via fermenting OMWW may be a promising alternative to deal with OMWW. However, whether or not olive wine from OMWW still reserves its original bioactivities remains unclear. Objective This study examines antioxidant activity of olive wine fermented from OMWW. Materials and methods Hydroxytyrosol in olive oil was determined by HPLC. Total flavonoid, total polyphenol and in vitro antioxidant activities were measured by spectrophotometry. Aged mice were intragastricly administered 7, 14 and 28 mL/kg olive wine consecutively for 30 d. Afterward, levels of malonaldehyde (MDA), protein carbonyl, reduced glutathione (GSH) and activity of superoxide dismutase (SOD) were assayed in mouse plasma and liver. Results Contents of hydroxytyrosol, total flavonoid and total polyphenol in olive wine were 0.14 ± 0.01, 0.29 ± 0.06 and 0.43 ± 0.03 mg/mL, respectively. The IC50 value of olive wine to scavenge DPPH and hydroxyl free radicals was 2.5% and 3.2% (v/v), respectively. Compared with the solvent control group, olive wine with a dose of 28 mL/kg remarkably lowered mouse MDA concentration in liver, and reduced protein carbonyl level in plasma (p < 0.05). Meanwhile, olive wine at doses of 7 and 28 mL/kg notably enhanced SOD activity in both mouse plasma and liver (p < 0.05). The beneficial effect on liver was superior to that of γ-tocopherol. Conclusion The study demonstrated that olive wine from OMWW has potential for treating oxidative stress-associated diseases.

Topics: Administration, Oral; Animals; Antioxidants; Biomarkers; Biphenyl Compounds; Chromatography, High Pressure Liquid; Dose-Response Relationship, Drug; Female; Fermentation; Food-Processing Industry; Fruit; Glutathione; Hydroxyl Radical; Liver; Malondialdehyde; Mice; Olea; Oxidative Stress; Phenylethyl Alcohol; Phytotherapy; Picrates; Plants, Medicinal; Protein Carbonylation; Superoxide Dismutase; Wastewater; Wine

The chemical synthesis of new lipophilic polyphenols with improved properties presents technical difficulties. Here we describe the selection, isolation and identification of lipolytic bacteria from food-processing industrial wastes, and their use for tailoring a new set of compounds with great interest in the food industry. These bacteria were employed to produce lipolytic supernatants, which were applied without further purification as biocatalysts in the chemoselective and regioselective synthesis of lipophilic partially acetylated phenolic compounds derived from olive polyphenols. The chemoselectivity of polyphenols acylation/deacylation was analyzed, revealing the preference of the lipases for phenolic hydroxyl groups and phenolic esters. In addition, the alcoholysis of peracetylated 3,4-dihydroxyphenylglycol resulted in a series of lipophilic 2-alkoxy-2-(3,4-dihydroxyphenyl)ethyl acetate through an unexpected lipase-mediated etherification at the benzylic position. These new compounds are more lipophilic and retained their antioxidant properties. This approach can provide access to unprecedented derivatives of 3,4-dihydroxyphenylglycol with improved properties.

Topics: Acylation; Bacteria; Biocatalysis; Biphenyl Compounds; Candida; Esterification; Free Radical Scavengers; Hydroxybenzoates; Lipase; Lipolysis; Methoxyhydroxyphenylglycol; Phenylethyl Alcohol; Phylogeny; Picrates; Polyphenols; Stereoisomerism

The olive oil phenol hydroxytyrosol (3), as well its metabolite homovanillic alcohol (4), were subjected to chemoselective lipase-catalysed acylations, affording with good yield 10 derivatives (5-14) bearing C(2), C(3), C(4), C(10) and C(18) acyl chains at C-1. Hydroxytyrosol (3) and its lipophilic derivatives showed very good DPPH. radical scavenging activity. Compounds 3, 4 and their lipophilic analogues 5-14 were subjected to the atypical Comet test on whole blood cells: 3 and its analogues 5 and 6, with little hydrophobic character (logP

Topics: Acetylation; Bacteria; Biphenyl Compounds; Chemical Phenomena; Chemistry, Physical; Comet Assay; DNA; DNA Damage; Free Radical Scavengers; Fungi; Humans; In Vitro Techniques; Indicators and Reagents; Lipase; Mutagens; Oxidative Stress; Phenylethyl Alcohol; Picrates; Solubility

Typical components of the Mediterranean diet, such as olive oil and red wine, contain high concentrations of complex phenols, which have been suggested to have an important antioxidant role. The aim of the present work was to determine the inhibitory potency of compounds such as oleuropein, hydroxytyrosol, and other structurally related compounds, such as gallic acid, toward reactive oxygen species generation and free radical scavenging ability. The potency of these compounds was also examined with respect to protecting in vitro low-density lipoprotein oxidation. These studies indicate that complex phenols, such as hydroxytyrosol, and gallic acid both inhibit free radical generation and act as free radical scavengers. The use of three different approaches to determine antioxidant potency demonstrates that activity in one test does not necessarily correlate with activity in another. It was also demonstrated that the presence of two phenolic groups is not always associated with antioxidant activity.

Topics: Animals; Antioxidants; Aryl Hydrocarbon Hydroxylases; Bepridil; Biphenyl Compounds; Cytochrome P-450 CYP3A; Cytochrome P-450 Enzyme Inhibitors; Enzyme Inhibitors; Free Radical Scavengers; Gallic Acid; Humans; Iridoid Glucosides; Iridoids; Lipid Peroxidation; Lipoproteins, LDL; Male; Microsomes, Liver; Olive Oil; Oxidoreductases, N-Demethylating; Phenylethyl Alcohol; Picrates; Plant Oils; Pyrans; Rats; Rats, Wistar; Reactive Oxygen Species; Steroid 16-alpha-Hydroxylase; Steroid Hydroxylases