(一)表没食子儿茶素没食子酸酯对活性氧自由基的清除作用机制

Mechanism of scavenging effects of ( - ) -epi- gallocatechin gallate on active oxygen free radicals

本文研究了(一)表没食子儿茶素没食子 酸酯[(—)-EGCG]清除O_(?)和·OH的半数清除率SC_(50)、清除速率常数k和清除反应的化学计量因子n,用体外模型分析了药物对活性氧自由基的清除机制和(—)-EGCG自由基的启动及结构特点,推论药物的清除反应中心为B、D和A环,每分子药物可捕捉6个O_(?)或·OH,与化学计量因子n=6相符。

The concentration of 50% scavenging ratio (SC50) and the scavenging rate constants (k) and stiochiometric factor (n)were determined when ( - )-epigallocatechin gallate [(- )-EGCG] scavenging superoxide anion free radical (O2 ) and hydroxyl radical (OH). The mechanism of scavenging active free radicals of ( - )-EGCG and the promotion of ( -)-EGCG free radical and its structure were analyzed in vitro. Our results suggest that the centers of scavenging reaction of (-)-EGCG are B, D, and A cycles,and each ( -)-EGCG traps six O2 or OH. It is in accord with the value of stiochiometric factor n = 6.