六种粘细菌095B06次生代谢产物的分离、鉴定及初步生物学活性研究

目的:研究粘细菌的活性次生代谢产物的分离、鉴定及生物学活性.方法:利用稻瘟霉模型筛选活性菌株,对活性菌株Myxococcus xanthus 095B06发酵液的甲醇提取物采用硅胶柱色谱、凝胶柱色谱、高效液相色谱等手段进行分离纯化化学成分,通过1HNMR、13CNMR和ESI-MS对化合物进行结构鉴定,利用纸片扩散法和四甲基偶氮唑盐比色法对单体化合物进行生物活性评价.结果和结论:从粘细菌095B06发酵液中分离鉴定了4个大环内酯类化合物、1个甾醇类化合物及1个生物碱类化合物,它们分别为Avermectin A1a(1)、Avermectin A2a(2)、Avermectin B1a(3)、Avermectin B2a(4)、麦角甾-7,22-双烯-3,5,6-三醇(赛勒维甾醇)(5)和4-喹啉羧酸(6).化合物1～5为首次从粘细菌中分离得到,且化合物2和4对肿瘤细胞SMMC-7721具有较强的抑制作用,其IC50均为5 μg/ml.

Isolation, identification, and biological characterization of 6 secondary metabolites extracted from Myxococcus xanthus 095B06

Objective:To study the isolation,identification, and biological characteristics of the secondary metabolites of myxobacteria.Methods: A growth inhibition model of Pyricularia oryzae was used to screen the active microbes.The compounds extracted with methanol from the fermentation broth of Myxococcus xanthus 095B06 were separated by silica chromatography,gel filtration chromatography,and high-performance liquid chromatography.The chemical structures of the compounds were identified by 1HNMR,13CNMR,ESI-MS,and EI-MS techniques.The bioactive activities of the separated compounds were evaluated by Kirby-Bauer Disc Diffusion method and MTT method.Results: Six compounds,namely,Avermectin A1a,Avermectin A2a,Avermectin B1a,Avermectin B2a,ergosta-7,22-dien-3,5,6-triol,and 4-quinolinecarboxylic acid,were obtained.Conclusion: Compound 1,2,3,4,and 5 have been isolated from myxobacteria for the first time and compound 2 and 4 can strongly inhibit the growth of SMMC-7721 cell line,with both IC_50 values being 5 g/ml.