1株发光杆菌Photorhabdus asymbiotica的次级代谢产物研究

摘要：目的 研究1株发光杆菌Photorhabdus asymbiotica抗革兰阴性菌的活性次级代谢产物。方法 以抗革兰阴性菌活性为导向，采用大孔吸附树脂、MCI柱色谱，以及反相高效液相色谱等多种分离纯化技术，利用HR-ESIMS和NMR等波谱学方法，分离Photorhabdus asymbiotica发酵液中的化合物并鉴定其结构。结果 从菌株Photorhabdus asymbiotica中获得3个次级代谢产物，并鉴定为darobactin(1)、环(L-色氨酸-L-脯氨酸)(2)和环(L-脯氨酸-L-苯丙氨酸)(3)。其中化合物1对大肠埃希菌、肺炎克雷伯菌和鲍曼不动杆菌均具有显著的抗菌活性。结论 化合物1为发光杆菌Photorhabdus asymbiotica中主要的抗革兰阴性菌活性化学成分。

Secondary metabolites from a bacterium of Photorhabdus asymbiotica

Abstract Objective To study the secondary metabolites with anti-Gram-negative bacteria activity produced by a bacterium of Photorhabdus asymbiotica. Methods The secondary metabolites were isolated from the fermentation of Photorhabdus asymbiotica by a variety of chromatographic techniques including macroporous resin, MCI gel, and reverse high performance liquid chromatography. Their structures were identified by HR-ESI-MS, NMR spectralanalysis, and comparison with the spectral data from literatures. Results Three known compounds were identified as darobactin (1), cyclo (L-Pro-L-Phe) (2), and cyclo (L-Trp-L-Pro) (3). Compound 1 showed significant antibacterial activity against Escherichia coli, Klebsiella pneumoniae, and Acinetobacter baumannii with the MICs values of 1.56~12.5 μg/mL. Conclusion Darobactin is the main bioactive component of the bacteria Photorhabdus