Rate Constants for Hydrogen Atom Abstraction by (alpha)-Tocopheroxyl Radical from Lipid, Hydroperoxide and Ascorbic Acid

The rate constants for each reaction of (alpha)-tocopheroxyl radical with methyl linoleate, t-butyl hydroperoxide and ascorbic acid, and also the bimolecular reaction of (alpha)-tocopheroxyl radicals were measured by a stopped-flow ESR technique in order to understand the antioxidant action of (alpha)-tocopherol. It was suggested that (alpha)tocopheroxyl radical is primarily reduced by ascorbic acid in vivo.