Active Oxygens Generation by Flavonoids

概要

論文の詳細を見る
The hydrogen peroxide (H_2O_2)-generating effects of 14 flavonoids were investigated. Seven out of 14 flavonoids tested were found to generate H_2O_2 in an acetate buffer of pH 7.4. The H_2O_2-generating abilities of flavonoids decrease in the order of myricetin>baicalein>quercetin>(-)-epicatechin>(+)-catechin>fisetin=7,8-dihydroxy flavone. This ability was observed in flavonoids with either a pyrogallol or catechol structure, and the pyrogallol-type flavonoids generated more H_2O_2 than the catechol-types. The amount of H_2O_2 generated by myricetin (pyrogallol-type flavonoid) was proportional to its concentration and to the reaction time until about 4 h. In addition, H_2O_2 generation by myricetin was dependent on the amount of dissolved oxygen in the buffer, and it was inhibited by the addition of superoxide dismutase.These results suggest that the flavonoids generate H_2O_2 by donating a hydrogen from their pyrogallol or catechol structure to oxygen, through a superoxide anion radical.It was also found that flavonoids which generated more H_2O_2 were more powerful antioxidants in the NADPH-dependent lipid peroxidation of rat microsomes.
公益社団法人日本薬学会の論文
1998-02-15