6个不同种源梓树叶片的总酚含量和抗氧化性能的比较

总酚含量和抗氧化性能水平的高低是植物做为药用价值的重要指标。为了比较不同种源梓树叶片的总酚含量和抗氧化性能的差异，寻找抗氧化性能较强的梓树品种，首先进行了提取方法的优化，然后使用最优的提取方法提取了6个种源（辽宁、甘肃、河南、湖北、湖南、贵州）1年生梓树叶片的抗氧化物质，测定了总酚含量、还原力、羟自由基清除率、DPPH清除率、ABTS清除率和FRAP铁离子还原能力。结果表明:使用60%甲醇，料液比1∶10，超声提取90 min，获得梓树叶片的总酚含量较高，辽宁、甘肃和河南种源梓树叶片的总酚含量和抗氧化能力较高，而湖南、湖北和贵州地区的较低。总酚含量和抗氧化能力具有显著的地理差异，北方梓树的显著高于南方。可为选育具有更高抗氧化性能的林木提供指导，为进一步研究抗氧化性能差异的机理提供基础。

Comparison of Total Phenols and Antioxidant Activity in the Leaves of Catalpa ovate from Six Provenances

The total phenolic content and antioxidant activity are important indicators for medicinal plants. To compare the differences in total phenolic contents and antioxidant activities among the leaves of 1-year-old Catalpa ovate from different provenances to select varieties with srong antioxidant activity, the leaves from 6 regions such as Liaoning, Gansu, Henan, Hubei, Hunan and Guizhou were collected. The total phenol content, reducing power, rates of free radical scanvenging capability, such as hydroxyl radical, DPPH radical and ABTS, and FRAP iron clearance reducing ability were measured. The results showed that optimal extraction conditions were solvent: 60% methanol, ratio of material to solvent: 1∶10, and time of ultrasonic wave aided extraction: 90 min. Samples collected from Liaoning, Gansu, and Henan were found higher phenol contents and strong antioxidant activity, while those from Hunan, Hubei, and Guizhou were lower. Significant geographical differences were observed: varieties from northern China were superior than those from southern China. The results would provide guidance for the selection of varieties with high antioxidant activity as well as for anti-oxidation mechanism study.