塔克拉玛干沙漠来源链霉菌Streptomyces sp. 90次级代谢产物的研究

摘要：目的 研究塔克拉玛干沙漠来源链霉菌Streptomyces sp. 90的次级代谢产物。方法 采用反相硅胶柱色谱、葡聚糖凝胶Sephadex LH-20、半制备HPLC方法分离纯化该菌株的发酵粗提物，通过ESI-MS、NMR等波谱数据分析并与文献对比确定化合物的结构，采用琼脂扩散法和稀释法分别追踪化合物抗菌活性及评价化合物1的最低抑菌浓度(minimal inhibitory concentration, MIC)，利用LC-MS法初步研究光照和温度因素对化合物1稳定性的影响。结果 从Streptomyces sp. 90中分离得到6个化合物，通过质谱和核磁共振等方法确定了化合物的结构，分别为已知化合物collismycin A(1)、collismycin B(2)、pyrisulfoxin A(3)、SF2738C(4)、SF2738D(5)和SF2738F(6)；化合物1对表皮葡萄球菌表现出较明显的抑制作用，MIC值在8~16 μg/mL之间，对甲氧西林耐药的金黄色葡萄球菌(MRSA)表现出一定抑制作用，MIC在32~64 μg/mL，而对革兰阴性菌抑制活性较弱。化合物1在溶液状态下对光照敏感，而对温度较稳定。结论 化合物1为放线菌Streptomyces sp. 90主要活性物质，但对光照不稳定。

Studies on secondary metabolites from the Taklimakan Desert-derived Streptomyces sp. 90

Abstract Objective To study the secondary metabolites produced by a Taklimakan desert-derived Streptomyces sp. 90. Methods The secondary metabolites were isolated and purified from the fermentation extracts of the Streptomyces sp. 90 by reversed-phase silica gel column chromatography, Sephadex LH-20, and semi-preparative HPLC. The chemical structures of these compounds were elucidated and confirmed by ESI-MS, NMR spectral analysis, and comparison with the data of literature. The bioassay-guided isolation of secondary metabolites and MICs of compound 1 against 37 bacterial strains were obtained by the paper disc-agar diffusion and agar dilution method. The stability of compound 1 was studied by LC-MS. Results A total of six compounds were isolated from the extracts of the Streptomyces sp. 90 and identified as known collismycin A(1), collismycin B(2), pyrisulfoxin A(3), SF2738C(4), SF2738D(5), and SF2738F(6). Compound 1 showed strong inhibitory activity on Staphylococcus epidermidis with the MICs value of 8~16 μg/mL, and displayed moderate anti-MRSA activity with the MICs value of 32~64 μg/mL and weak activity against Gram-negative bacteria strains. The solution of compound 1 is sensitive to light but stable to temperature. Conclusion Compound 1 is the main bioactive substance of Streptomyces sp. 90, and it is unstable to