Abstract:To investigate the components with antioxidant activity from Citrus aurantium L. var.amara Engl., the Citrus aurantium L. var.amara Engl. alcohol extract was purified by several traditional column chromatography technologies such as silica gel column, dextran gel column and polyamide column, combined with HPLC,NMR and other modern technologies. Three compounds were separated from chloroform and ethyl acetate extract and identified as homoeriodictyol, bergaptol and choerospondin. All of them were first isolated from Citrus aurantium L. var.amara Engl. Antioxidant activities were examined by four external evaluation systems(Reductive power measurement,ABTS, DPPH and FRAP). Bergaptol showed excellent antioxidant ability based on reductive power measurement, which is better than that of homoeriodictyol and choerospondin. By ABTS method the radical-scavenging clearance of bergaptol and homoeriodictyol were 100% and 95%, respectively, at the concentration of 800 μg/mL, which was equal or close to positive control. DPPH radical scavenging ability measurement revealed that the antioxidant effect of bergaptol was the best, and the clearance reached 79% at the highest concentration. FRAP assay indicated that the FRAP value of bergaptol and homoeriodictyol were 1.5585 and 1.1239, respectively, close to 2.1682 of positive control.
