链霉菌I08A1776产生的水溶性链丝菌素

Water-soluble streptothricins from Streptomyces sp.I08A 1776

目的分离纯化链霉菌108A1776发酵液中的水溶性抗耐药结核活性成分。方法利用离子交换、反相和亲水作用等多种色谱技术进行分离纯化，通过现代波谱学方法鉴定活性成分结构。结果分离得到3个水溶性活性成分，其结构分别确定为链丝菌素EO）、N^β-乙酰链丝菌素E（2）和β-乙酰链丝菌素D（3）。链丝菌素E（1）对结核分枝杆菌H37Rv和临床分离耐药株的MIC值为0．25～1．0μg／mL。结论首次利用亲水作用色谱分离纯化微生物发酵液中的水溶性活性化合物。亲水作用色谱在微生物水溶性次级代谢产物的分离纯化中具有广阔的应用前景。链丝菌素E具有较强的体外抗耐药结核分枝杆菌活性。

Objective To investigate the water-soluble anti-tubercular agents from the culture broth of Streptomyces sp. I08A 1776. Methods Compounds were purified by a combination of chromatographic methods, including ion-exchange, RP-HPLC, and hydrophilic interaction chromatography （HILIC） techniques. Structures of the isolates were identified by IR, MS, CD, and 1D and 2D NMR spectroscopic data analysis. The antimicrobial activities against Staphylococcus aureus, Enterococcus faecalis, Bacillus subtilis, Mycobacterium smegmatis, Mycobacterium tuberculosis H37Rv and clinically isolated MDR strains, Pseudomonas aeruginosa, Morganella morganii, Escherichia coli, and Candida albicans were evaluated by the micro-broth dilution method. The cytotoxicities against human lung adenocarcinoma （A549）, hepatocellular carcinoma （HepG2）, and cervical cancer （Hela） cells lines were evaluated by using the MTT method. Results Three water-soluble streptothricins were obtained. Their structures were elucidated as streptothricin E Nβ, 1）, Nβ-acetylstreptothricin E （AN-201 I, 2）, and Nβ-acetylstreptothricin D （AN-201 II, 3）. Streptothricin E showed anti-tubercular activities against M. tuberculosis H37Rv and clinically isolated drug-resistant strains with MIC values of 0.25-1.0pg/mL. Compounds 1-3 were inactive against the A549, HepG2, and Hela cancer cells （IC50 values 〉 10gmol/L）. Conclusion Three water-soluble streptothricins were isolated by hydrophilic interaction chromatography method for the first time. HILIC can be used for the isolation and purification of water-soluble secondary metabolites from microbial cultures broth. Streptothricin E （1） showed significant anti-tubercular activities.