Study On Secondary Metabolites From Two Strains Of Marine Sponge-associated Streptomyces

Sponge-associated actinomycetes are the important source of marinenatural products. In our present work, secondary metabolites from twostrains of sponge-associated streptomyces (S71and S59) which wereisolated from the South China Sea were investigated.Two strains of streptomyces were selected for compounds isolation bychemical and biological activity screening and the fermentation conditionsoptimization. Isolation and purification of the secondary metabolites wereperformed by means of chromatography (thin layer chromatography, silicagel and reversed-phase silica gel column chromatography, SephadexLH-20column chromatography and high performance liquidchromatography). Finally, Five compounds (compounds1-5) wereobtained from the strain S71.Structure identification of five compounds was elucidated throughspectrometry analyses (mass spectroscopies and nuclear magneticresonance spectroscopies). Compounds1-4belong to glutarimideantibiotics and4was identified from nature for the first time. Compound5is a known indole alkaloid.The antimicrobial activities of compounds1-3were determined in aprimary screen against Staphylococcus aureus, Pseudomonas aeruginosaPAO1and Mycobacterium smegmatis mc2155. And the results indicatedno antimicrobial activities for compounds1-3against the microorganismstested. The antitumor activities of compound3were studied with humangastric carcinoma cell line (MGC-80-3) and human liver carcinoma cellline (SMMC7221). As a result, the IC50was found to be27.16μg/mL and 112.75ug/mL, respectively. Therefore, compound3shows little or noantitumor activities against MGC-80-3and SMMC7221cell lines.The secondary metabolites identified from sponge-associatedactinomycetes will enrich the diversity of marine natural products.