用电化学方法研究槲皮素等的抗超氧阴离子自由基作用

 目的：研究槲皮素、芦丁、维生素C(VC)、维生素E(VE)对超氧阴离子自由基的清除作用。方法：利用邻苯三酚自氧化体系产生超氧阴离子自由基，用单扫示波极谱法进行检测。结果：槲皮素与芦丁都能有效地清除超氧阴离子自由基(0₂)，但芦丁的清除作用比槲皮素的弱些，它们的IC₅₀值分别为17.8μmol·L^-1和16.3μmol·L^-1。二者清除能力强弱的差别可从其结构特征方面进行合理地解释。相同浓度的VC和VE对O₂的抑制率分别为76.8%和25.7%。结论：槲皮素和芦丁均为黄酮类化合物，能够有效地清除超氧阴离子自由基，用电化学方法可以直接检测其对自由基的清除作用，在此体系中，VC清除O₂的作用强于VE。

The anti superoxide anion radical effect of quercetin etc. studied by electrochemistry method

OBJECTIVE: To investigate the anti superoxide anion radical effect of quercetin, rutin, VC, VE. METHODS: The single sweep oscillopolarography method was applied to determine the O₂ that was produced by the autoxidation of pyrogallol. RESULTS: Quercetin and rutin inhibited the formation of O₂ effectively, however, the scavenging ability of rutin was weaker than that of quercetin, and their IC₅₀ was 17.8 μmol·L^-1 and 16.3 μmol·L^-1 respectively. The difference of scavenging effect of these two compounds can be interpreted from their chemical structures. The inhibitory rates of VC and VE at the same concentration were 76.8%, 25.7% respectively. CONCLUSIONS: Quercetin and rutin are flavonoid and effective superoxide radical scavengers. The scavenging effect of flavonoids on superoxide anion radical can be determined directly by electrochemistry method. The scavenging effect of VC on O₂ is stronger than that of VE in this system.