小叶锦鸡儿根不同极性组分的抗氧化活性研究

Antioxidative Activity of Flavonoid Fractions with Different Polarity from Roots of Caragana microphylla Lam.

为研究小叶锦鸡儿(Caragana microphylla Lam.)根不同极性组分的抗氧化活性,按极性梯度对粗提物进行液-液萃取获得4个组分,测定了不同极性组分总黄酮含量和各项抗氧化能力指标,并研究了各组分总黄酮含量和抗氧化能力的相关性。结果表明:小叶锦鸡儿根部粗提物和不同极性组分在不同抗氧化体系中均表现出不同程度的抗氧化活性;粗提物、正己烷层、二氯甲烷层、乙酸乙酯层和水层对DPPH.清除能力的EC50分别为0.68,6.12,0.23,0.07,2.23 mg/mL;不同极性组分羟自由基清除能力与其总黄酮含量呈显著相关性,而DPPH.和超氧阴离子清除能力及总抗氧化能力与其总黄酮含量未表现出显著相关性。结果证明,小叶锦鸡儿根部不同极性组分具有较强的抗氧化活性,是良好的天然抗氧化剂。

To investigate the antioxidative activities of the fractions with different polarity from roots of Caraga- na microphylla Lain. ,four fractions were obtained by liquid-liquid extraction with stepwise gradient of solvents fol- lowing ultrasound-aid crude extraction,and the total flavonoid contents and antioxidative activities of the crude ex- tract and fractions along with their correlations were determined. The results showed that in different antioxidative determination systems,the crude extract and the fractions with different polarity exhibited antioxidative activities to different extents. The EC50 values of DPPH. scavenging activity for the crude extract and n-hexane, dichloromethane, ethyl acetate and water fractions were 0. 68 ,6.12 ,0. 23 ,0. 07 ,2. 23 mg/mL, respectively. There is a significant cor- relation between the total flavonoid content and the hydroxyl free radical scavenging activity of the four fractions. However,significant correlations were not found between the total flavonoid content and DPPH. scavenging activity, superoxide anion radical activity and total antioxidative capacity. The results suggest that the fractions of different polarity from roots of C. microphylla possess high antioxidative activities and can be good candidates for natural an- tioxidants.