马齿苋中总黄酮提取工艺优化及其抗氧化活性研究

Optimization on Extraction Process of Total Flavonoids from Purslane and Study on Their Antioxidant Activities

采用直接回流法提取马齿苋中总黄酮,通过单因素实验与正交实验对提取工艺进行了优化;并以芦丁为对照品,采用分光光度法对马齿苋中的总黄酮含量进行了检测;同时研究了马齿苋总黄酮提取液对羟基自由基(·OH)和超氧阴离子自由基(·O-2)的清除效果,并与Vc的抗氧化活性进行了比较。确定马齿苋中总黄酮最优提取工艺为:提取时间50min、水浴温度90℃、提取溶剂为30%乙酸乙酯、固液比1∶50(g∶mL),在此条件下,马齿苋总黄酮提取率可达7.15mg·g-1。当马齿苋总黄酮浓度为0.18 mg·mL-1时,对·OH的清除率高达73.12%,对·O-2的清除率可达49.02%,相同浓度时,其抗氧化活性低于Vc。

Total flavonoids were extracted from purslane by direct reflux. The extraction process was opti- mized by single factor experiment and orthogonal experiment. The content of total flavonoids from purslane was determined by spectrophotometric method using rutin as reference substance. Scavenging efficiency of total fla- vonoids from purslane to · OH and · O2- were studied and compared with that of Vc. The optimal extraction process was obtained as follows, extraction time of 50 rain,water bath temperature of 90 ℃ ,30% ethyl acetate as extraction solvent,and solid-liquid ratio of 1 ：50（g · mL）. Under the optimal conditions,the extraction rate of total flavonoids from purslane could reach as high as 7.15 mg · g-1. When the concentration of total fla- vonoids from purslane was 0. 18 mg · mL-1 ,the scavenging rate of · OH was 73.12% and the scavenging rate of · O2- was 49.02%. The antioxidant activity of Vc was better than those of total flavonoids from purslane at the same concentration.