Study On The Secondary Metabolites And Biological Activity Of Four Actinomycetes

135 strains of actinomyectes, which was isolated from Marine sediments of the South China Sea, was Screened. Bioassay was conducted using in vitro antitumor activities against six tumor cell lines A549, DU145, H1299, HCT15, HEP3B and SF268 and using antibacterial model against Bacillus subtilis, Bacillus thuringiensis, Staphyloccocus aureus, Escherichia coli,and using brine shrimp. More than 46.5% of the fermentation extracts have different anti-tumor effect on NCI cancer cell lines in vitro, over 21.5% of the fermentation extracts have different inhibitory effect on Bacillus subtilis, Bacillus thuringiensis, Staphylococcus aureus and Escherichia coli. Also 39.7% of the fermentation extract have shrimp bio-lethal.Streptomyces sp. SCSIO1666 and Marinactinospora thermotolerans SCSIO 00652 was screened to produce bioactive secondary metabolites. The fermentation condition of the strain was optimized and the bioactive secondary metabolites were isolated by means of solvent extraction, normal and reversed-phase silica gel. The structures of compounds were identified by physicochemical properties and spectral analyses.Two bioactive compounds were isolated and their structures were identified as tirandamycin A (1) and tirandamycin B (2) from Streptomyces sp. SCSIO1666. The fermentation titer of the two compounds was improved more 500-fold when 3% marine salt was added. Also, the fermentation titer of tirandamycin A was found to be greatly improved by addition of XAD-16 resin.Three indole alkaloids were isolated from Marinactinospora thermotolerans SCSIO 00652. Two of which are pendolmycin and methylpendolmycin, and anther is a sugar base, may be new compounds, to be further structurals analysis. And fiveβ-carboline compounds were isolated from mutant strain Marinactinospora thermotolerans SCSIO 00652 142 H-4-7. Three are new compouds, the other two need to be further structural analysis. There are a lot of secondary metabolites active compounds as a new drug lead compounds. To solve mankind now faces drug-resistant strains, and new diseases are emerging challenges.Moreover, 11 terrestrial actinomycetes were screened for biological activity. The strains streptomyces sp. 100266 which have ultraviolet absorption similar with Streptolydigin was selected large-scale fermentation. Four compounds which all have a UVλmax 355nm was isolated, two of which are new compounds, the structure needs to be further analysis.