头花蓼多酚不同极性溶剂萃取物的抗氧化活性

Antioxidant activities of different polar solvent extracts from polyphenol of Polygonum capitatum

目的:比较头花蓼多酚不同极性溶剂萃取物抗氧化活性并考察活性与多酚含量的相关性。方法:将头花蓼提取物过大孔树脂纯化后得到头花蓼精多酚样品,采用不同极性有机溶剂对头花蓼精多酚样品进行液-液萃取,将头花蓼多酚样品分为石油醚相、氯仿相、乙酸乙酯相、正丁醇相、水相不同极性溶剂萃取物。测定不同极性溶剂萃取物的总多酚含量,研究各萃取物清除DPPH自由基、羟自由基及ABTS自由基能力,分析抗氧化活性与多酚含量关系,并采用HPLC对乙酸乙酯萃取物进行初步鉴定。结果:头花蓼不同极性萃取物均有抗氧化活性,乙酸乙酯相抗氧化活性最好,清除DPPH、ABTS、羟自由基的IC50值与多酚含量呈现相关性(r=-0.988,r=-0.742,r=-0.563),槲皮苷是乙酸乙酯相的主要抗氧化成分之一。结论:乙酸乙酯相提取物可作为分离头花蓼抗氧化活性物质的重点,多酚是抗氧化的主要活性成分。

The antioxidant activities of different polar solvent extracts of Polygonum multiflorum were studied and the correlation between activity and polyphenol content was investigated.Method： The polyphenols from Polygonum capitatum were extracted by macroporous resin,and the samples were extracted with different polar organic solvents.The samples were divided into petroleum ether phase,chloroform phase,ethyl acetate phase,n-butanol phase,aqueous phase with different polar solvent extracts.The total polyphenol content of different polar solvent extracts was determined. Scavenging activities of the extracts on the DPPH free radicals,hydroxyl radicals and ABTS free radicals were studied.The relationship between antioxidant activity and polyphenol content was analyzed.And the ethyl acetate extract was identified by HPLC.Result： The antioxidant activity of ethyl acetate was the best,and IC50 of the DPPH,ABTS and hydroxyl radicals were correlated with the content of polyphenols（ r =-0.988,r =-0.742,r =-0.563）. Quercetin was the main antioxidant component of ethyl acetate phase. Conclusion： Ethyl acetate phase extract could be used as important part seperated antioxidant substances and polyphends were the main active ingredients of antioxidant activity.