Sources Of Marine Actinomycetes Study Of Secondary Metabolites

Actinomycetes are the most economically and biotechnological valuableprokaryotes for bioactive natural products. The study on actinomycetes has attachedgreat concern of many countries in the world. Therefore, the pioneering on newresources of actinomycetes and the new methods on this is an important content.There are over20,000bioactive secondary metabolites from microorganism so far,about half of the compounds were produced by actinomycetes. In this paper, marinederived atinomycetes were isolated from sponge and mangrove soil. According toantitumor bioassay screening and chemical analysis, three actinomycetes were chosento research their secondary metabolites. On the purpose of finding new halogenated, astudy was launched to investigate actinomycetes which has halogenase genes. Thisstudy include the bioactivity screening of actinomycete strains, selection of workingstrains, optimization of culture conditions, bioassay-guided fractionation, structuraldetermination and anti-tumor bioassay of pure compounds.Fifty-two actinomycetes strains were isolated from marine sponges samples.Onehundred and twenty-two actinomycetes strains were isolated from mangrove soil. And45actinomycetes strains were anti-tumor bioassay strains through chemical analysisand antitumor bioassay screening. Through bioassay testing and HPLC analysis, threeactinomycetes strains were the future study. The fermentation conditions weredetermined after a series of experiment about bioassay testing and HPLC and TLCanalysis.Twenty compounds were isolated from the EtOAc extracts of the fermentationschromatographed by repeated, silica gel column, Sephadex LH-20andsemi-preparative HPLC. From GW31-48,12compounds (1-12) were isolated,including5cycloheximide (1-5)，4dipeptides (6-9)，1indole alkaloid（10），2benzenederivates（11-12）, and compound1and2are new. From AH17-3,4compounds(13-16) were isolated, including4polyketone compound. From AH7-2,7compoundswere isolated, and four structures of the7pure compounds were determined, including1polyketone compound(17) and2thiazole compounds(18,19). Their bioactivewere on the study.To acquire halogenated compounds, one micromonospora strain which wasproved have halogenase gene has been researched. Unfortunately, there were nohalogenated compounds be found.In conclusion,20compounds were isolated from3actionmycetes strains.Chemical analysis and antitumor bioassay screening combine gene screen is a goodmethod, and can overcome some problems such as the finding of old compounds havehigh activity and new compound have low activity. The result of study is a footing forthe further study.