Vitamin E Research Today is a free monthly online journal that collates and summarizes the latest research about Vitamin E, including details on benefits, dosage, supplements, antioxidants.

Evidence for alpha-tocopherol regeneration reaction of green tea polyphenols in SDS micelles.

Zhou B, Wu LM, Yang L, Liu ZL

National Laboratory of Applied Organic Chemistry, Lanzhou University, Lanzhou, Gansu 730000, Peoples' Republic of China. bozhou@lzu.edu.cn

The synergistic antioxidant mechanism of alpha-tocopherol (vitamin E) with green tea polyphenols, i.e., (-)-epicatechin (EC), (-)-epigallocatechin (EGC), (-)-epicatechin gallate (ECG), (-)-epigallocatechin gallate (EGCG), and gallic acid (GA), was studied by assaying the kinetics of the reaction of alpha-tocopheroxyl radical with green tea polyphenols by stopped-flow electron paramagnetic resonance, the inhibition of linoleic acid peroxidation by these antioxidants, and the decay of alpha-tocopherol during the peroxidation. It was found that the green tea polyphenols could reduce alpha-tocopheroxyl radical to regenerate alpha-tocopherol with rate constants of 0.45, 1.11, 1.31, 1.91, and 0.43 x 10(2) M(-1) s(-1) for EC, EGC, ECG, EGCG, and GA, respectively, in sodium dodecyl sulfate micelles. In addition, these second-order rate constants exhibited a good linear correlation with their oxidation potentials, suggesting that electron transfer might play a role in the reaction.

Published 13 December 2004 in Free Radic Biol Med, 38(1): 78-84.
Full-text of this article is available online (may require subscription).

© 2004-2008 Vitamin E Research Today. All Rights Reserved.