Preliminary Studies On The Secondary Metabolites Of Actinomycetes From Several Different Environments

Natural products deriving from actinomycetes are very important sources for drug discovery. Among them, antibiotics are the best known and the most valuable. Actinomycetes from different sources can produce different secondary metabolites with various biological functions. In order to search for new compounds with useful biological activities, a study on the secondary metabolites of actinomycetes from different sources was carried out.Under the guidance of antibacteria activity, three sarubicin compounds (1～3) were isolated from the GYD solid-state fermentation of acid red soil-derived Streptomyces strain G15. Compound 2 is a new nature product and its absolute configuration is S. The antibacterial activity test indicated that, compound 1 and 2 just inhibited gram positive bacterias, whereas compound 3 exhibited different inhibition effects against gram positive and negative bacterias.1‰ NaCl was added into the GYM liquid fermentation medium, which showing a certain degree of marine adaptability of actinomycete strain 8.102. Two piloquinone compounds (4 and 5) were isolated from the secondary metabolites of strain 8.102, among which compound 5 is a new one. Both of them didn’t show any activity during the antibacterial activity test. Besides, nine pathogenic bacterias and two pathogenic fungus were served as indicator bacteria to conduct the biological activity screening of 22 marine actinomycete strains. The screening results showed that secondary metabolites derived from marine actinomycetes could inhibit a variety of pathogenic bacterias, which had great potential in new drug research and development.With the help of liquid chromatography-mass spectrometry, eight antibiotics with biological value were isolated from the fermented products of seven actinomycete strains:nanchangmycin (polyether), quinomycin (ester peptides), strevertene (macrolide), lasalocid (polyether), reveromycin (polyketide), staurosporine (alkaloid), BE-24566B (aromatic ketone) and triedimycin (β-lactone).Summarily, five compounds were obtained from strians G15 and 8.102, including two new compounds, and their antibacterial activities were tested. Moreover, eight different antibiotics were found during the preliminary research about the secondary metabolites of seven actinomycete strains.