肾茶多酚提取工艺及其抗氧化活性研究

Extraction and Antioxidant Activity of Polyphenols from Clerodendranthus spicatus

采用回流提取法,进行单因素试验和L9（34）正交试验,确定肾茶多酚最佳提取工艺;并通过测定1,1-二联苯基-2-苦肼自由基（DPPH·）和羟自由基（·OH）清除率评价其抗氧化活性。得到的肾茶多酚的优化提取工艺为液料比10∶1（m L/g）,50%乙醇回流3次,每次提取2 h,肾茶多酚提取率为3.60%,优选的提取工艺稳定可靠,重现性好。体外抗氧化活性实验结果显示：肾茶多酚的抗氧化能力随质量浓度的增大而增强,在1~10μg/m L浓度范围内和100~1250μg/m L浓度范围内,其清除DPPH自由基和羟基自由基的能力略强于抗坏血酸,两者的对DPPH自由基半数抑制浓度分别为5.78和6.31μg/m L;对羟基自由基的半数抑制浓度为851.1和940.1μg/m L。

Reflux extraction method was used to extract the polyphenols from Clerodendranthus spicatus in this study. Single factor experiments and the L9 （3^4） orthogonal experiment was applied to optimize the extraction conditions. In addition,the antioxidant activities of the extract were evaluated by DPPH · and · OH scavenging assays. The optimal ex- traction conditions for extracting polyphenols were as follows： liquid/solid ratio of 10：1 mL/g, ethanol concentration of 50%, 2 h per time, and extract 3 times. Under the optimized conditions, the extraction yield of total polyphenol was up to 3.60%. In vitro antioxidant activity of total polyphenols increased with the increasing of concentration,the scavenging abilities against DPPH ·and · OH were stronger than vitamin C within the range of 1-10 μg/mL and within the range of 100-1250 μg/mL,respectively. The ICso values were 5.78 and 6.31 μg/mL toward DPPH · ,and 851.1 and 940.1 μg/ mL toward · OH, respectively.