Antioxidant Activity of Cu (II)-His Complex on the Photosensitized Oxidation of Linoleic Acid in FMN-Light System

抄録

The effects of His and Cu (II)-His complex were examined on photosensitized oxidation of linoleic acid (LA) in the FMN (riboflavin 5'-phosphate)-light system. The generation of superoxide anion (0₂^-) and the peroxidation of LA were promoted by addition of His, and they were inhibited by addition of Cu (II)-His complex. The peroxidation of LA by 0₂^-resulted in the formation of H₂O₂ and linoleic acid hydroperoxide (LAHPO). Cu(II)-His complex promoted the decomposition of H₂0₂ and LAHPO during generation of 0₂^-, and the decomposition of H₂0₂ by the complex resulted in limited OH formation. Cu (II)-His complex inhibited both oxygen uptake and the accumulation of peroxides, and the decreases in both were similar. These results suggest that the antioxidant activity of Cu(II)-His complex may be attributed to the quenching of 0₂^- rather than to catalytic action on decomposition of peroxides.