The potential health benefits of wine are frequently attributed to the antioxidant properties of its phenolic constituents. In this study, the antioxidant efficacies of five phenolic components of a red wine were assessed in the presence of hydrogen peroxide (H2O2) and metal ions ([Fe3+], [Fe2+], [Cu2+]), using functional thin-layer chromatography (TLC). The pH of the red wine sample was adjusted to 2.0 without prior extraction. Chromatographic separation was performed using silica gel 60 F254 TLC plates with toluene-ethyl acetate-formic acid 30:25:5 (ν/ν) as mobile phase. Five phenolic components (one flavonol and four phenolic acids) were identified. In independent experiments, the red wine was challenged with a range of oxidant systems comprising H2O2, redox-active metals (Fe3+ and Cu2+), and hydroxyl radical generators (Fe2+-H2O2 and Cu2+-H2O2). The results showed that all phenolic compounds gradually diminished in a concentration- and time-dependent manner. All systems tested showed that quercetin, caffeic acid, and gallic acid possessed the highest antioxidant efficacies, while chlorogenic acid and p-coumaric acid exhibited lower antioxidant capacities. Based on these results, the ranking order of the antioxidant efficacies of the phenolic components in the red wine sample was as follows: quercetin > caffeic acid > gallic acid > p-coumaric acid > chlorogenic acid. This is the first application of functional TLC to delineate the antioxidant profile of red wine in the presence of different oxidant systems involving redox-active metals and H2O2, and to rank the individual components according to their antioxidant efficacies.
A. Waterhouse, Ann. NY Acad. Sci. 957 (2002) 21–36.
Waterhouse A., '' (2002) 957Ann. NY Acad. Sci.: 21-36.
Waterhouse A.Ann. NY Acad. Sci.20029572136)| false
A. Kondrashov, R. Ševčík, H. Benáková, M. Koštířová, S. Štipek, Eur. J. Clin. Nutr. Metab. 4 (2009) e41–e46.
Štipek S., '' (2009) 4Eur. J. Clin. Nutr. Metab.: e41-e46.
Štipek S.Eur. J. Clin. Nutr. Metab.20094e41e46)| false
B. Halliwell, Free Radic. Biol. Med. 46 (2009) 531–542.