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Study On Bioactive Secondary Metabolites From Three Strains Of Polar Microbes And The Influence Factors Of Their Diversities

Posted on:2016-02-26Degree:MasterType:Thesis
Country:ChinaCandidate:D H MeiFull Text:PDF
GTID:2191330479487609Subject:Applied Chemistry
Abstract/Summary:PDF Full Text Request
The natural environment with low temperature, drought, strong radiation and less nutrition is the most famous characteristic of the polar regions.which makes the polar microorganisms produce secondary metabolites with unique molecular structures, interesting bioactivities and special mechallisms.. Various types of constituents, including aromatic nitro compounds, peptides and terpenoids, had been reported from different polar microorganism. In recent years, investigation on the diversity of polar microorganisms and their bioactive metabolites, has become one of the hot spots.In our investigation on secondary metabolites of Arctic actinomycete with new structure or potent bioactivity, this study used Streptomyces sp. from polar sources as the major research object to explore the structure types of secondary metabolites and the influence factors of the chemical diversity.By solvent extraction, column chromatography on Sephadex LH-20 and silica gel, and HPLC, secondary metabolites were investigated from three strains of polar actinomycete including the Arctic Streptomyces sp. 623 F, the Antarctic krill associated Streptomyces sp. NJ-94 and an unidentified Antarctic actinomycete strain A19-2. Four compounds(1-4) were isolated from Streptomyces sp. 623 F, together with three compounds(5-7) from A19-2 and six compounds(7-12) from Streptomyces sp. NJ-94.The structures of these compounds were identified as2,9-Dihydroxy-4-phenyl-cyclopenta[a]naphthalen-5-one(1),8,9-Dihydroxy-2-methoxy-4-phenyl-cyclopenta[a]naphthalen-5-one(2),9-Hydroxy-2-methoxy-4-phenyl-cyclopenta[a]naphthalen-5-one(3), vulgamycin(4),Cerebroside B(5), 3-(4-hydroxybenzyl)hexahydropyrrolo[1,2-a]pyrazine-1,4-dione(6), 3-benzyl-7-hydroxyl-hexahydropyrrolo[1,2-a]pyrazine-1,4-dione(7),3-(1-methylpropyl)-hexahydropyrrolo-[1,2-a]pyrazine-1,4-dione(8), cyclo-(Pro-Leu)(9), Tryptophan(10), Gephyromycin( 11) and4,10-dihydroxy-2-methyl-1-dodeca-1,4-lactone(12). Compounds 1-3 are new structures with rare skeleton, and their bioassay and total synthesis, as well as the structural elucidation of some other minor compounds are still in process.Study on the diversity of secondary metabolites under different culture conditions of Streptomyces sp. NJ94 was carried out by LC-TOF MS data analysis.We tried to add SAHA, a histone deacetylase inhibitor, in the culture mediums forbetter diversity of secondary metabolites and a hogher yield of Gephyromycin analogues. And we also tried to use Antarctic krill protein as N-source of the culture mediums, to investigate the chemical diversity changes. We found that histone deacetylase inhibitor and different N-source of the mediums should be important influence factors of secondary metabolites’ diversity.This study have identified new structure constituents, and tried to exploy some special influence factors of the chemical diversity, which indicated that the polar microbes have high values for research and great potential for development. Has made the beneficial attempt for the late epiphytic microbial metabolism of krill,and provide the basis for the wide application of Antarctic krill protein in fermentation industry.
Keywords/Search Tags:polar microbes, Streptomyces sp., secondary metabolites, influence factors of diversity
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