地肤子抑菌活性成分筛选

Screening of Antibacterial Active Constituents from Fructus kochiae

以最小抑菌浓度为指标,采用二倍稀释法分别测试地肤子乙醇提取物中的石油醚相、乙酸乙酯相、正丁醇相和水相萃取物对4株细菌和5株植物病原菌的抑制作用;再对抑菌活性较强的萃取物进行分离纯化,通过二倍稀释法测试所分离化合物的抑菌活性,并对其结构进行表征。结果表明,正丁醇相萃取物的抑菌活性最强,从中分离得到3个化合物,其中化合物Ⅰ的抑菌活性较强,对大肠杆菌具有显著的抑制作用,其最小抑菌浓度为31.3μg·mL-1,经1 HNMR、IR及高分辨质谱等鉴定化合物Ⅰ为齐墩果酸。齐墩果酸有较强的抑菌活性,是地肤子抑菌活性的物质基础。

Using the minimal antibacterial concentration as an index,we determined the antibacterial activities of four fractions from ethanol extract against four bacteria and five plant pathogenous fungi by a double-dilution method,such as petroleum ether fraction,acetic ether fraction,n-butanol fraction,and water fraction.Moreover,we separated and purified a fraction with higher antibacterial activity,determined the antibacterial activities of purified compounds by a double-dilution method,and characterized the structures of the compounds.The results indicate that n-butanol fraction shows the highest antibacterial activity,from which three compounds are separated.Among them,compoundⅠhas the highest antibacterial activity,which shows strong antibacterial activity against Escherichia coli with the minimal antibacterial concentration of 31.3μg·mL^-1.Furthermore,compoundⅠis identified as oleanic acid by 1HNMR,IR,and high resolution mass spectrometer.Oleanic acid has high antibacterial activity,which is the material basis of the antibacterial activity of Fructus kochiae.