海洋芽孢杆菌B-9987中抗MDR菌活性成分研究

Identification of anti-MDRB compounds from the marine-derived Bacillus sp.B-9987

目的挖掘具有优良多重耐药菌(MDR)抗菌活性的次级代谢产物,为海洋新药研发提供分子多样性。方法对海洋芽孢杆菌B-9987进行大发酵,将发酵产物进行提取分离,每一步分离过程进行MDR活性追踪。结果 B-9987粗提物对4株MDR菌(金黄色葡萄球菌CCARM 3090、沙门氏菌CCARM 8250、大肠杆菌CCARM 1009、粪肠球菌CCARM 5203)具有良好的抗菌活性。通过HPLC分离纯化及MS、NMR等波谱分析获得了化合物1(Macrolactin F)和化合物2(Bacillaene A)。化合物1对MDR菌没有抗菌活性。由于化合物2对光、温度、氧气十分不稳定,无法直接测试活性。对含有化合物2的组分进行活性测试,确定了B-9987的MDR菌抗菌活性来自于Bacillaene类化合物。结论鉴定了B-9987中的抗MDR菌活性成分。

Objective To discover antibacterial secondary metabolites against multi-drug resistant bacteria（MDRB）from marine-derived Bacillus sp.B-9987.Methods The culture broth of B-9987 was extracted with EtOAc,and the EtOAc extract was further separated by open column chromatography.The pure compounds were finally obtained by HPLC purification,and their structures were determined by combination of MS and NMR data analysis.The antibacterial activity test against MDRB was carried out in each step of the separation process.Results Compounds 1（Macrolactin F）and 2（Bacillaene A）were obtained by combination of a variety of chromatographic and spectroscopic analysis.Compound 1showed no antibacterial activity against MDRB.Since compound2 was very unstable against light,oxygen,as well as room temperature,it was difficult to be directly subjected to the antibacterial activity test.However,the fraction containing compound2 as the major component exhibited good antibacterial activity against 4 MDR bacterial strains（Staphylococcus aureus CCARM 3090,Salmonella Typhimurium CCARM 8250,Escherichia coli CCARM 1009,and Enterococcus faecium CCARM 5203）,indicating the anti-MDRB activity of B-9987 was attributed to bacillaene compounds.Conclusion The bioactive component against MDRB from B-9987 was identified.