Peroxyl-Radical Reaction of Retinyl Acetate in Solution

Abstract

Retinyl acetate suppressed the free radical-induced oxidation of methyl linoleate. Retinyl acetate was reacted with an alkylperoxyl radical in two solvent systems, methanol and benzene. The alkylperoxyl radical was generated by the thermal decomposition of a free radical initiator, 2,2′-azobis(2,4-dimethylvaleronitrile), at 37°C. The reaction products were isolated by HPLC and their structures were identified. The main product in methanol was 14-hydroxy-13-methoxyretinyl acetate in addition to some minor products. The reaction in benzene gave some products with low yields. They were 5,6-epoxyretinyl acetate, 11,14-epoxyretinyl acetate, and 5,6,11,14-diepoxyretinyl acetate. The results indicate that retinyl acetate is capable of scavenging peroxyl radicals by its conjugated polyene structure.