密蒙花花蕾不同提取部位的抗氧化活性研究

Study on Antioxidant Activity of Different Extraction Parts from Flower Buds of Buddlejae flos

目的:比较密蒙花花蕾不同提取部位的体外抗氧化活性。方法:用60%乙醇提取密蒙花花蕾得乙醇粗提物(ET),用水分散后,依次用石油醚、乙酸乙酯和正丁醇萃取ET得各部位样品PE、EA、BU和水部位样品(SH);以二丁基羟基甲苯(BHT)为阳性对照。采用1,1-二苯基-2-苦基苯肼(DPPH)、2,2′-联氨-双(3-乙基苯并噻唑啉-6-磺酸)二氨盐(ABTS)自由基清除法和铁离子还原/抗氧化能力分析(FRAP)法分别考察各部位样品的抗氧化能力,计算半数抑制浓度(IC50)及抗氧化当量TEAC值。结果:与其他部位样品比较,ET与EA具有较强的抗氧化活性,EA清除DPPH、ABTS自由基的IC50分别为13.75、9.78μg/ml,ET为14.93、11.41μg/ml;EA对DPPH自由基的清除能力强于BHT(IC50为18.71μg/ml)。EA、ET、BHT的TEAC值分别为1 657.67、1 586.25、1 581.68μmol/g。结论:密蒙花花蕾的乙酸乙酯提取物具有较好的抗氧化能力。

OBJECTIVE：To compare antioxidant activity of different extraction parts from flower buds of Buddlejae flos in vitro. 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 dibutyl 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 radical 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 scavenging 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（IC50was 18.71 μg/ml）. TEAC of EA,ET and BHT were 1 657.67,1 586.25 and 1 581.68 μmol/g. CONCLUSIONS：The ethyl acetate extract from flower buds of B. flos has good antioxidant activity.