Isolation And Identification Of Secondary Metabolites From Several Strains Of Polar Marine Microbes

Marine microorganisms have abundant resources. It plays a very important role as secondary metabolite producers. The secondary metabolites of marine microorganisms are an important compounds source of drug lead. At present, a series of new bioactive substances have been found. Because of the cold natural environment in the polar ocean area, the polar microorganisms and its metabolites showed higher novelty in structure and function. In recent years, many compounds with novel structure or significant activity have been isolated from the polar microorganisms, such as aromatic nitro compounds, peptides, terpenoids, alkaloids and other skeleton types, which provided rich resources for the drug research and development.With 4 polar microorganism strains as the research material, including the Arctic actinomycete Streptomyces sp.604 F which contained halogenase gene validated in previous study, this study has two main purposes, the first is to obtain novel compounds with small molecular structure, especially halo-containing constituents,and to accumulate the foundation for marine natural products; the other one is to isolate compounds with good biological activity from these strains. This paper takes the Arctic actinomycete strains Streptomyces sp.514 F, 604 F and 527 F, and the unidentified microorganism NJES13 associated with Antarctic krill as the research objects, to isolate and identify the chemical constituents, and to carry out deep investigation on cultures of Streptomyces sp.604 F for their metabolites diversity. By extraction and column chromatography, including chromatography on silica gel,reverse-phased silica gel, Sepadex LH-20, MCI gel and macroporus resin, and semi-preparative HPLC, more than 20 compounds were obtained, and 12 of them have been identified on the basis of spectroscopic analyses(including EI-MS, HR-ESI-MS,1H-NMR,13C-NMR,1H-1H COSY, HMBC and HSQC), and by comparison with the literatures. 12 compounds were identified as Antimycin A1b(1), Antimycin A4a(2), Antimycin A2a(3),Antimycin A3a(4), Antimycin A1a(5), Vulgamycin(6), 8-deoxyenterocin(7),2-Hydroxytetrangomycin(8), gephyromycin(9), a new compound(10),4’,7-Dihydroxy-3’-methoxyisoflavone(11) and 2-Acetamidophenol(12). It’s the first report of compounds 1-7 from the microbes derived from Arctic sediment, and it’s the first time that these two types of compounds were identified as metabolites of the same source. Compounds 8-10 are found in the new genus for the first time from the Antarctic actinomycetes, and the compound 10 is a new compound with structure in further elucidstion.Combined with the verification and cloning of halogenase gene from Streptomyces sp.604 F by our collaborating group, the culture condition modification was also carried out by metabolites diversity analysis, which provides the guidance to find halo-containing constituents, and to the isolation and identification of new structure products. At present, studies have shown that polar microorganism has great medicinal potential. Therefore, it is necessary to carry out isolation and identification of new structure and bioactive metabolites.