甜茶中鞣花酸抗氧化作用研究

目的]研究甜茶中鞣花酸的抗氧化作用。方法]以甜茶根为原料,经提取、溶剂萃取、重结晶等手段,得到了鞣花酸晶体;采用体外试验对甜茶中鞣花酸的清除DPPH.自由基能力及还原能力进行了研究,并用磷钼酸盐法测定了甜茶中鞣花酸的总抗氧化活性。结果]鞣花酸清除DPPH.效果明显,并且具有速度快、用量少、抗氧化能力强等特点;当浓度为0.10 mg/ml时,鞣花酸对DPPH.自由基的清除率达到92.5%以上。鞣花酸的还原能力随着浓度的增大而变强;与BHT相比,当浓度低于0.5 mg/ml时,鞣花酸的还原能力低于BHT;而当浓度达到0.5 mg/ml时,鞣花酸的还原能力强于BHT。鞣花酸总抗氧化活性随着浓度及加入时间的增大而增大;当浓度为1.2mg/ml时,EA的抗氧化性没有BHT强,但1 h后EA的抗氧化性比BHT稍强。结论]甜茶鞣花酸清除自由基的能力很强,具有开发利用意义。

Study on the Antioxidant Activity of Ellagic Acid from Rubuso suavissimus S.Lee

Objective] To study the antioxidant activity of ellagic acid from Rubuso suavissimus S.Lee.Method] The ellagic acid was extracted and purified form R.suavissimus by solvent extraction and recrystallization,and its DPPH· scavenging capacity and reducing capacity were studied by in vitro test.In addition,the total antioxidant activity of ellagic acid was determined by phosphomolybdate method.Result] The ellagic acid could effectively eliminate DPPH· free radicals,which was characterized by fast speed,low dosage and strong antioxidant activity.When the concentration of ellagic acid was 0.10 mg/ml,the DPPH· scavenging rate reached more than 92.5%.The reducing capacity of ellagic acid was improved by raising concentration,which was lower than that of BHT at the concentration below 0.5 mg/ml and higher than that of BHT at the concentration above 0.5 mg/ml.Furthermore,the total antioxidant activity increased with the increase of concentration and with the extension of action time.Conclusion] It is significant to develop and utilize ellagic acid with strong free radical scavenging capacity.