Abstract: 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.

Key words: Caragana microphylla Lain., Flavonoids, Polarity, Antioxidative activity

CLC Number: 

• S793.3