几种松萝中松萝酸含量及提取物清除DPPH自由基能力测定

Measurement on Content of Usnic Acid in Several Usnea and the Activity of the Extractives Scavenging DPPH Free Radical

为了得到提取松萝酸的最佳原料,采用紫外分光光度法在波长284 nm处对长松萝、环裂松萝、粗皮松萝、桦树松萝、亚花松萝中松萝酸含量进行提取分析,结果表明,长松萝主要活性成分松萝酸含量最高,达到5.66%以上。以分光光度法测定抗坏血酸清除二苯基苦基苯肼(DPPH)自由基的能力并制作清除率曲线,将IC值作为评价试样清除DPPH自由基能力的指标,应用于松萝提取物清除DPPH自由基能力的测定。将试样和抗坏血酸的测定结果进行比较,发现几种松萝提取物的清除DPPH自由基的能力均不强。

For obtaining the best materiel that extract usnic acid, this experimentation mensurates content of usnic acid in Usnea longissima, U. diffracta, U. montis-fuji , U. betulina and U. subfloridana in UV-Visible Spectrophotometer at 284 nm waver and indagates reserve. The result of the experimentation indicates, the usnic acid is best in U. longissima, the content is more than 5.66 percent. And a spectrophotometric method for determining 1,1-diphenyl-2-picryl- hydrazyl（DPPH） free radical scavenging activity of ascorbic acid was put forword, The evaluating criterion of DPPH free radical scavenging activity was regarded as ＂IC50＂ by determining the scavenging rate curves . The DPPH free radical scavenging activity of the extractives from usnea were determined by this method. Compared with ascorbic acid , the extractives＇ activity is lower.