Purification and structural elucidation of three bioactive compounds isolated from Streptomyces coelicoflavus BC 01 and their biological activity

The strain Streptomyces coelicoflavus BC 01 was isolated from mangrove soil and used as inoculum for submerged fermentation. The fermented broth was extracted with ethyl acetate, the crude extract was subjected to silica gel column chromatography and the homogeneity of the isolated fractions was determined by TLC and then subjected to RP-HPLC for their purity. The purification steps led to the isolation of three pure bioactive compounds named as BC 01_C1, BC 01_C2 and BC 01_C3. The chemical structure of these three compounds was established on the basis of their spectroscopic studies like UV, IR, (1)H and (13)C NMR and GC–MS data by comparison with reference data from literature. The structure of the compound BC 01_C1 was established as 5-amino-2-(6-(2-hydroxyethyl)-3-oxononyl) cyclohex-2-enone. The compound BC 01_C2 was established as8-(aminomethyl)-7-hydroxy-1-(1-hydroxy-4-(hydroxylmethoxy)-2,3-dimethylbutyl)-2-methyl dodecahydro phenanthren-9(1H)-one and the compound BC 01_C3 was established as1-((E)-2-ethylhex-1-en-1-yl)2-((E)-2-ethylidenehexyl)cyclohexane-1,2-dicarboxylate. The MIC values of the three isolated compounds (BC 01_C1, BC 01_C2 and BC 01_C3) were found between 12.5–75 μg/ml for bacteria and 50–125 μg/ml for fungi used in this study. These compounds also possess in vitro antioxidant and anti-inflammatory activities.