染料木素及其乳糖苷清除自由基能力的研究

Free Radical Scavenging Activities of Genistein and Its Lactosides

采用DPPH法、Fenton反应-邻二氮菲-Fe2+光度法和邻苯三酚自氧化法,测定染料木素及其乳糖苷修饰物清除DPPH·、·OH和O2·能力。结果表明,染料木素及其乳糖苷修饰物清除DPPH·和·OH能力的顺序为:染料木素7,4'-二-O-β-D-吡喃乳糖苷>染料木素4'-O-β-D-吡喃乳糖苷>染料木素7-O-β-D-吡喃乳糖苷>染料木素;相反,在低浓度时,染料木素清除O2·的能力强于其乳糖苷修饰物,除染料木素和染料木素7-O-β-D-吡喃乳糖苷对O2·有弱抑制作用外,其他两种乳糖苷对邻苯三酚的自氧化速率均呈现负抑制,且随样液浓度的增加,抑制率降低。

The free radical scavenging activities ofgenistein and its lactocides were assessed by using three methods, namely the anti-DPPH free radical, Fenton reaction with 1,10-phenanthroline-Fe2＋ spectrophotometry and pyrogallol autoxidation assays. The results showed that the abilities of genistein and its lactosides in scavenging DPPH· and ·OH radicals are in the order of genistein 7,4＇ di-O-β-lactoside 〉 genistein 4＇-O-β-lactoside 〉 genistein 7--O-β-lactoside 〉 genistein. In contrast, genistein is effective in scavenging O2· than its lactosides at low concentration. Furthermore, the other two genistein lactosides have negative effects on inhibiting autoxidation rate ofpyrogallol except for genistein 7-O-β-lactoside. In general, the inhibiting rates to samples decrease with the concentration increase.