基因序列分析指导的海洋糖丝菌中特曲霉素X的发现  

Identification of tetracenomycin X from a marine-derived Saccharothrix sp.guided by genes sequence analysis

作　　者：刘玢[1,3] 谭亿[1] 甘茂罗[1,2] 周红霞[1] 王以光[1] 平欲晖[3] 李斌[3] 杨兆勇[1] 肖春玲[1] 

机构地区：[1]中国医学科学院、北京协和医学院医药生物技术研究所,北京100050 [2]中国医学科学院、北京协和医学院药物研究所,天然药物活性物质与功能国家重点实验室,北京100050 [3]江西中医药大学,江西南昌330004

出　　处：《药学学报》2014年第2期230-236,共7页Acta Pharmaceutica Sinica

基　　金：国家自然科学基金资助项目(81273414,81001386);天然药物活性物质与功能国家重点实验室开放课题资助项目(GTZK210302)

摘　　要：一株海洋来源的稀有放线菌（Saccharothrix sp．10—10）发酵液粗提物显示出较强的抗革兰阳性耐药菌活性。对该产生菌中可能参与次级代谢产物生物合成的主要关键酶系基因保守序列的聚合酶链反应fpolymerase chain reaction，PCR）分析，发现其II型聚酮合酶基因片段，与特曲霉素生物合成基因簇中的相关序列具有较高的同源性。经活性追踪，利用多种色谱方法从Saccharothrixsp．10-10发酵液中分离纯化得到特曲霉素x（tetracenomycin X，1），同时还得到氧代托马霉素（oxotomaymycin，2），该两种化合物为首次从海洋糖丝菌属放线菌中发现，并利用2DNMR对这两个化合物的”CNMR数据进行了准确归属。体外活性结果表明，化合物1对甲氧西林耐药金葡菌（MRSA）和万古霉素耐药肠球菌（VRE）等耐药菌显示出显著的抗菌活性，最低抑菌浓度（MIC）为32-64μg·mL^-1；此外，化合物1还对多株人肿瘤细胞显示出较强的细胞毒活性，IC50值为5．1～18．0μmol·L^-1。The crude extracts of the fermentation broth trom a marine sediment-derived actmomycete strata, Saccharothrix sp. 10-10, showed significant antibacterial activities against drug-resistant pathogens. A genome- mining PCR-based experiment targeting the genes encoding key enzymes involved in the biosynthesis of secondary metabolites indicated that the strain 10-10 showed the potential to produce tetracenomycin-like compounds. Further chemical investigation of the cultures of this strain led to the identification of two antibiotics, including a tetracenomycin （Tcm） analogs, Tcm X （1）, and a tomaymycin derivative, oxotomaymycin （2）. Their structures were identified by spectroscopic data analysis, including UV, 1D-NMR, 2D-NMR and MS spectra. Tcm X （1） showed moderate antibacterial activities against a number of drug-resistant pathogens, including methicillin-resistant Staphylococcus aureus （MRSA） with the MIC values in the range of 32-64 gg-mL-1. and vancomycin-resistant Enterococci （VRE） pathogens, In addition, 1 also displayed significant cytotoxic activities against human cancer cell lines, including HL60 （leukemia）, HepG2 （liver）, and MCF-7 （breast） with the IC 5o values of 5.1, 9.7 and 18.0 ~rnol.L-1, respectively. Guided by the PCR-based gene sequence analysis, Tcm X （1） and oxotomaymycin （2） were identified from the genus of Saccharothrix and their 13C NMR data were correctly assigned on the basis of2D NMR spectroscopic data analysis for the first time.

关 键 词：海洋放线菌 糖丝菌 基因探查 耐药菌 特曲霉素X 氧代托马霉素 

分 类 号：R284[医药卫生—中药学]