不同种质鱼腥草总酚、黄酮含量及其抗氧化活性

目的：提取并测定16份鱼腥草材料(含1份峨眉蕺菜)叶片总酚和黄酮含量，研究其体外抗氧化活性。方法：以95%乙醇超声提取并测定16份综合农艺性状较好的鱼腥草材料以显色及紫外分光光度测定成分含量，DPPH、ABTS法测定抗氧化活性。结果：16份鱼腥草总酚含量变异范围为7.01～15.0mg/g；黄酮含量变异范围为3.56～11.0mg/g；DPPH法抗氧化值最小为84.7μmol/g，最大为248μmol/g；而ABTS法抗氧化能力的变幅为 78.4～218μmol/g。以总酚和黄酮含量、DPPH法以及ABTS法抗氧化能力进行聚类分析，按欧氏距离大于70可将16份鱼腥草材料分为两类。其中Ⅰ类包含11份鱼腥草材料(含峨眉蕺菜)，其总酚和黄酮含量低，抗氧化能力弱。Ⅱ类包含5份鱼腥草材料，其总酚和黄酮含量高，体外抗氧化能力强。总酚、黄酮含量和体外抗氧化活性指标间相关性均达极显著水平。结论：16份鱼腥草材料总酚、黄酮含量和抗氧化活性的不同，主要是由于遗传背景所致；且总酚和黄酮含量高，体外抗氧化能力强的材料多为染色体数目大于80者。

Total Phenol and Favonoid Contents and Antioxidant Activity of Houttuynia cordata Thunb.

Leaves of sixteen H. cordata cultivars including H. emeiensis Z.Y. Zhu et S. L. Zhang were extracted with 95% ethanol by ultrasonic-assisted method. The contents of total phenolic acids and flavonoids were determined spectrometrically, and their antioxidant capacities were evaluated. The results showed that total phenol contents in dried leaves of H. cordata were in the range of 7.01－15.0 mg/g, and flavonoid contents varied from 3.56 to 11.0 mg/g. DPPH radical scavenging rates of the leaf extracts of H. cordata varied from 84.7 to 248 μmol/g, and ABTS radical scavenging rates from 78.4 to 218 μmol/g. Cluster analysis based on the contents of polyphenol and flavonoid as well as antioxidant activity in vitro indicated that 16 H. cordata cultivars could be classified into two subgroups. The group I included 11 H. cordata cultivars with relatively low total phenol content, flavonoid content, and DPPH and ABTS radical scavenging capacity, while group Ⅱ showed higher contents of polyphenol, flavonoid, and antioxidant activity in vitro. The chromosome number did not show any significant correlation with the contents of polyphenol and flavonoid or antioxidant activity in vitro, while total phenolic acid and flavonoids contents had an obvious correlation with antioxidant activity.