研究白花蛇舌草(Hedyotis diffusa Willd)总黄酮的提取工艺及其体外抗氧化活性。以白花蛇舌草总黄酮提取率为评价参数,通过单因素试验、正交试验优化提取工艺;测定了总还原力及Fe2+螯合力、羟自由基和超氧阴离子清除能力研究白花蛇舌草总黄酮的抗氧化活性。结果表明,用95%乙醇与白花蛇舌草粉末按40∶1(m L∶g),在90℃下提取180 min,此时提取率最高,达(2.22±0.01)%。体外抗氧化活性结果显示白花蛇舌草总黄酮具有较强的总还原力,Fe2+螯合率最高为90%,羟自由基和超氧阴离子的清除率分别达79%、77%。白花蛇舌草总黄酮具有显著的体外抗氧化活性,具有进一步开发利用的价值。
This study was to optimize the conditions of extraction of total flavonoids from Hedyotis diffusa Willd and detect their antioxidant activities in vitro. Using extraction rate as the evaluation index,single factor experiments and orthogonal test were adopted to optimze the extraction process. Then,four antioxidant parameters of total flavonoids from Hedyotis diffusa Willd,including total reducing power,Fe-(2+) chelating,hydroxy radical scavenging,and superoxide anion radical scavenging capacities,were measured. The results showed that the optimum conditions of extraction were as following :ethanol concentration was95%,the ratio of liquid to solid was 40∶1(m L∶g); extraction time 180 min and temperature,90 ℃. Under these conditions,the extrction ratio was(2.22±0.01)%. The total flavonoids from Hedyotis diffusa Willd had showed high total reducing power,their chelating rate of Fe-(2+) reached 90%,the radical scavenging activities against hydroxyl radical and superoxide anion were 79%and 77%,respectively. So the antioxidant activities in vitro of flavonoids from Hedyotis diffusa Willd is obvious,which is worth further being developed and utilized.