荷叶多酚体外抗氧化活性研究

Study on in Vitro Antioxidant Activity of Polyphenols Extracted from Lotus Leaves

探究荷叶中多酚类物质的抗氧化活性.以体积分数55%乙醇恒温浸提荷叶中的多酚类物质,得到粗多酚（LP-C）,经AB-8大孔树脂纯化得纯化多酚（LP-P）,LP-C经大孔树脂吸附依次由30%乙醇和50%乙醇洗脱,得级分LP-30和LP-50;对上述4组样品的总还原力、羟基自由基清除率和亚硝酸盐清除率进行测定,采用HPLC-DAD法初步分析LP-30和LP-50成分.各组样品在质量浓度0.02-0.2mg/mL范围内总还原力、清除羟基自由基活力和清除亚硝酸盐活力有良好的量效关系;经HPLC-DAD分离,级分LP-30出现3个主峰,LP-50出现7个主峰.荷叶多酚具有优良的抗氧化活性.

The researh aimed to investigate the antioxidant activity of polyphenols from lotus leaves.LP-C was the polyphenols extracted with 55 % ethyl alcohol at a constant temperature and LP-P was the total polyphenols purified by AB-8 macroporous resins. LP-30 and LP-50 were obtained by gradiently eluting polyphenols absorbed on macroporous resins.Total reducing power, hydroxy radical scavenging rate and nitrite sacvenging rate were measured for the above four samples. In additon, the HPLC-DAD method was used to analyze constituents of LP-30 and LP-50 preliminarily.The four samples exhibited strong to- tal reducing power, hydroxy radical scavenging activity and nitrite scavenging activity, which was obviously related to the concentration（0.02-0.2 mg/mL）.Three peaks in LP-30 and five peaks in LP-50 were determined by HPLC-DAD separation.Polyphenols in lotus leav.es had excellent in vitro antioxidant activity.