Reaction of 8a-hydroperoxy tocopherones with ascorbic acid.

8a-Hydroperoxy tocopherones, prepared from the photooxidation of α-, γ- and δ-tocopherols, were allowed to react with ascorbic acid in ethanol. The hydroperoxy tocopherones were reduced to 8a-hydroxy and 8a-ethoxy tocopherones which in turn were reduced to tocopherols by ascorbic acid. The tendency of the hydroperoxy tocopherones to form tocopherols during the reaction correlated with vitamin E activities of tocopherols. The results indicate that α-tocopherol and ascorbic acid can act synergistically on the quenching of 1O2. The inhibitory effects of α-tocopherol and ascorbic acid were examined on the chlorophyll-sensitized photooxidation of methyl linoleate and soybean oil. At the initial stage of the oxidation, the inhibitory effect of α-tocopherol was lengthened in the presence of ascorbic acid.