中文摘要：

目的研究链霉菌CPCC203718中的抗菌活性次级代谢产物。方法发酵液经乙酸乙酯萃取、正相硅胶柱色谱、Sephadex LH-20凝胶柱色谱和半制备HPLC等方法进行分离纯化，利用多种现代波谱技术进行化合物结构鉴定。结果从链霉菌CPCC203718发酵液中分离鉴定了9个化合物，分别为：macrolactin B（1）、环（4-羟基-脯氨酸-亮氨酸）（2）、环（脯氨酸-酪氨酸）（3）、对羟基苯乙醇（4）、对羟基苯甲醛（5）、环（苯丙氨酸-甘氨酸）（6）、3-羟基吡啶（7）、环（缬氨酸-脯氨酸）（8）、germicidin A（9）。结论从链霉菌CPCC203718发酵液中得到9个化合物，其中化合物1具有良好的抗金黄色葡萄球菌活性，MIC为80μmL，化合物4具有抗肺炎克雷伯菌活性，MIC为512μg／mL。

英文摘要：

Objective To investigate antibacterial secondary metabolites from Streptomyces sp. CPCC 203718. Methods The fermentation borth was extracted with EtOAc, and the EtOAc extract was isolated and purified by silica gel column chromatography, Sephadex LH-20 column chromatography and semi-preparative HPLC. The structures of isolated compounds was elucidated by extensive spectroscopic analyses. Results Nine compounds were isolated from the fermentation broth of Streptomyces sp. CPCC 203718 and elucidated as macrolactin B（1）, cyclo-（4- hydroxyl-Pro-Leu）（2）, cyclo-（Pro-Tyr）（3）, p-hydroxyphenethyl alcohol（4）, p-hydroxybenzaldehyde（5）, cyclo-（Phe-Gly）（6）, 3-hydroxy pyridine（7）, cyclo-（Val-Pro）（8）, germicidin A（9）. Conclusion Nine compounds were obtained from the fermentation borth of Streptomyces sp. CPCC 203718. Compound 1 shows significant antibacterial activity against Staphylococcus aureus with MIC values of 8μg/mL, compound 4 shows antibacterieal activtity against Klebsiella pneumonia with MIC values of 512μg/mL.