大叶蟹甲草不同萃取部位抗氧化活性研究

目的研究大叶蟹甲草不同萃取部位的抗氧化活性。方法采用ABTS、DPPH自由基及还原性反应体系，利用分光光度法测定大叶蟹甲草的总提液、乙酸乙酯层、正丁醇层和石油醚层在不同浓度下的抗氧化能力及其总酚含量。结果大叶蟹甲草的不同萃取部位对AB＇IS、DPPH自由基均具有较强的清除能力及还原能力，其结果与浓度呈良好的量效关系。其中乙酸乙酯层抗氧化能力最强，在浓度为0．62mg／mL时，对ABTS自由基的最大清除率为91．57％，对DPPH·的最大清除率为94．87％，与同浓度VC的清除率接近，且其IC50分别为0．066mg／mL、0．004mg／mL，测得乙酸乙酯层总酚含量最高，达10．45％。大叶蟹甲草具有较好的抗氧化能力，其中乙酸乙酯层抗氧化能力最显著，与总酚含量有较大的相关性，同时该结果也客观地反映了DPPH法、ABTS-＋法及还原性法测定大叶蟹甲草抗氧化活性的准确性。

Antioxidant activity from different extractione of cacalia firma kom

Object：study on the antioxidant activity from different extraction of cacalia firma kom.Methods： Using ABTS, DPPH radical and reducing reaction, determination the total extracts ,Ethyl acetate, butanol layer and layer of cacalia firma kom. in different concentrations of the antioxidant capacity and total phenolic content. Results： The results showed a good dose-concentration relationship.The acetidin fraction of caealia firma kom. Show the most potent antioxidant activities in each assay. When the concentration of 0.62mg/mL,showing 91.57% in the ABTS radical scavenging, 94.87% in the DPPH radical scavenging. With the same concentration of the radical scavenging close to the VC. And each IC50 are 0.066mg/mL,0.004mg/mL.Therefore, our study verified that the butanol fraction has strong antioxidant activities which are correlated with its high level of phenolics. The phenolics concent of the acetidin fraction is 2.9 （mg/20mg）.Conclusions： The cacalia firma kom. has good antioxidant capacity. The aeetidin fraction antiorddant capacity significantly, And total phenolics content have a greater correlation. Meanwhile, the results also reflect the ABTS o ＋ method is objective, DPPH method and reducing method for the determination of antioxidant activity of cacalia firma kom.