Quenching Reactions of Triplet State Riboflavin by Vitamin C: A Theoretical Investigation

摘要

Vitamin C (ascorbic acid), the water-soluble, small-molecule antioxidant, is of great biological significance [1, 2]. Previous studies [3, 4] demonstrated that vitamin C can inhibit the photo-oxidative damage caused by riboflavin which can induce Type-I and II photosensitized oxidation mechanisms [5-7]. Considering the fact that many anti-oxidants can inhibit the riboflavin's photosensitizing damage through deactivating its triplet state [7-9], it is of significance to investigate the reactions of vitamin C with triplet state riboflavin, which may contribute to the protective effect of vitamin C. In the present study, the quenching mechanisms of triplet state riboflavin by vitamin C were explored by means of density functional theory (DFT) calculations, which have been widely used in investigating both the antioxidant and photosensitization mechanisms of various bioactive compounds [7, 11-14].