茶多酚体外助氧化作用的自由基机理

Radical Mechanism of Prooxidant Effect on Tea Polyphenols(TP)in vitro

从茶叶中分离得到的茶多酚及其主体成分(-)-表没食子儿茶素没食子酸酯——(-)-EGCG在体外碱性条件诱发下能产生O_2^(?)和多酚类半醌阴离子自由基,(-)-EGCG 的产生能力强于茶多酚复合体,茶多酚的这一特性可能是在高浓度时产生毒性反应的实质,是高浓度下清除自由基作用减弱的原因。

Superoxide anion radical and semiquinone anion radicals were producedby tea polyphenols and(-)-EGCG extracted from tea in alkaline solutionin vitro.The potency of production of(-)-EGCG was stronger than that ofTP.It might be a reason on toxicological effect and weaker scavengingeffect at high concentration.