アミノフェノール／遷移金属イオン複合体による活性酸素生成と構造特異性

抄録

Prooxidant properties of aminophenol compounds including 2-(o-)，4-(p-) and 3-(m-) isomers were analyzed. Aminophenol compounds/transition metal-dependent production of reactive oxygen species was evidenced by the inactivation of aconitase, the most sensitive enzyme to oxidative stress in permeabilized yeast cells. Aminophenol compounds of 2-, and 4-isomers produced reactive oxygen species in the presence of copper (cupric) ion. The inactivation required sodium azide the inhibitor of catalase, suggesting that the superoxide radical produced from the 2- and 4-aminophenol/transition metal complex is responsible for the inactivation of aconitase. However, 3-aminophenol compound showed no inactivating effect on the aconitase, and 3-isomer did not produce the reactive oxygen species. Aminophenols of 2- and 4-isomers showed a potent reducing activity of copper (cupric) ion, and further scavenging activity of DPPH radical, but 3-aminophenol showed only a little effect. Reducing activity of aminophenols may produce periferryl ion and causing continuous generation superoxide anion by redox cycling. Acetaminophen showed no prooxidant activity, but 4-aminophenol the constituent of this drug could produce reactive oxygen species in the presence of transition metals. Side effect of excess acetaminophen may be related to the prooxidant activity of aminophenol/metal complex.