尿酸、キノリン環化合物/遷移金属複合体による活性酸素生成

抄録

Prooxidant properties of uric acid and xanthurenic acid as quinoline compound were analyzed. Production of reactive oxygen species was evidenced by the inactivation of aconitase, the most sensitive enzyme to oxidative stress in permeabilized yeast cells. Uric acid and xanthurenic acid produced reactive oxygen species in the presence of iron (ferrous) ion. The inactivation required sodium azide the inhibitor of catalase and KCN the inhibitor of Cu, Zn-SOD and cytochrome c oxidase, suggesting that the superoxide radical produced from these compounds/transition metal complex is responsible for the inactivation of aconitase. Uric acid showed a potent reducing activity of copper (cupric) ion, and further scavenging activity of DPPH radical, and xanthurenic acid showed reducing activity lower than uric acid. Uric acid and xanthurenic acid may produce periferryl ion and causing continuous generation superoxide anion by redox cycling. Toxicity of these compounds may be related to their prooxidant activities.