中文摘要：

目的对分离自我国南海红树林底泥的链霉菌Streptomycessp．H41—26菌株的发酵物抗菌活性成分进行分离和鉴定。方法对链霉菌Streptomycessp．H41．26菌株的发酵菌丝体采用95％乙醇提取，醇提取物经乙酸乙酯萃取获得抗菌活性部位，通过ODS开放柱层析分离和反相高效液相制备纯化。结果分离得到4个化合物，经NMR IMS等波谱学方法分别鉴定为：放线菌素D（1）、放线菌素X2（2）、放线菌素Xβ（3）31放线菌素Xa（4）。结论化合物1～4在0．1mg／mL时，对大肠埃希菌（ATCC8739）、金黄色葡萄球菌（ATCC6538P）、伤寒沙门菌（ATCC6539）、乙型副伤寒沙门菌（50094）和乙型溶血性链球菌（ATCC32204）具有明显的抗菌活性，其中化合物2在0．01mg／mL时，对除大肠埃希菌外的其他4种细菌抑制效果仍很明显。

英文摘要：

Objective To study the chemical constituents of the fermentation broth of an antibacterial Streptomyces sp. H41-26 which was isolated from the bottom soil of a mangrove zone in South China Sea. Methods The cultured mycelia of this strain was extracted with 95% ethanol and the extracts were partitioned with ethyl acetate. Then the ethyl acetate fraction with antibacterial activity was purified by open ODS column chromatography and preparative HPLC. Results Four compounds were obtained and these compounds were identified to be actinomycin D（1）, actinomycin X2（2）, actinomycin X~（3） and actinomycin X（4） by extensive spectroscopic methods including NMR and MS, repectively. Conclusion Compounds 1N4 showed potential antimicrobial activity against E. coli （ATCC8739）, Staphyloecocus aureus （ATCC6538P）, Salmonella typhi （ATCC6539）, Rosenbach （50094）, Salmonella paratyphi B （ATCC32204）. Particularly, compound 2 had significant inhibitory activity against all strains except for E. cob （ATCC8739） at 0.01mg/mL.