A Novel Polyketide Antibiotic Produced by the Marine-Derived Streptomyces sp. CP26-58
San Francisco State University
Chemistry and Biochemistry
Actinomycetes separated from marine habitats have received extensive attention as a prolific source for bioactive secondary metabolites in the last decade. As part of our program to discover novel anticancer drug candidates from marine sediment-derived actinomycetes, the Streptomyces sp. CP26-58 strain separated from deep-water sediment collected in San Francisco Bay was identified as a producer of cytotoxic compounds based on the screening results against HeLa cells. To identify the active substances, this strain was grown in a seawater-based liquid medium (10L) containing soluble starch, yeast, and peptone as main ingredients. The organic extract was purified using chromatography techniques employing a combination of HP20 column chromatography and reverse phase HPLC. This purification process afforded three new secondary metabolites. Two of the isolated compounds were determined as new derivatives of naphthabline. The last new compound turned out to be a very unique polyketide class of compound based on analysis of the comprehensive 1D and 2D NMR data. In the presentation, the details of structure elucidation and biological activities of this new polyketide will be presented.