RESUMO
OBJECTIVE:To compare antioxidant activity of different extraction parts from flower buds of Buddlejae flos in vi-tro. METHODS:Ethanol crude extract (ET) was extracted from flower buds of B. flos with 60% ethanol and diffused by water;and petroleum ether,ethyl acetate and n-butanol were used to extract ET to obtain PE,EA,BU and water samples(SH). Using di-butyl hydroxy toluene(BHT)as positive control,the antioxidant capacity of PE,EA,BU and SH were investigated by using 1, 1-diphenyl-2-picrylhydrazyl(DPPH),2,2′-azino-bis(3-ethyl benzothiazoline-6-sulfonic acid)diammonium salt(ABTS)free radi-cal scavenging method and ironion reduction/oxidation resistance ability (FRAP) method. IC50 and antioxdant equivalent TEAC were calculated. RESULTS:Compared with other samples,ET and EA had stronger antioxidant activity,and IC50 of EA scaveng-ing DPPH and ABTS free radical were 13.75,9.78 μg/ml,and those of ET were 14.93,11.41 μg/ml;scavenging ability of EA to DPPH free radical was stronger than that of BHT(IC50 was 18.71 μg/ml). TEAC of EA,ET and BHT were 1 657.67,1 586.25 and 1 581.68μmol/g. CONCLUSIONS:The ethyl acetate extract from flower buds of B. flos has good antioxidant activity.