Planta Med 2015; 81 - PT34
DOI: 10.1055/s-0035-1556412

Two new cytotoxic meroterpenoids produced by the marine sediment-derived Streptomyces sp. CP26 – 58

SR Gee 1, H Martucci 1, T Gokey 1, AB Guliaev 1, WM Bray 2, RS Lokey 2, T Amagata 1
  • 1Department of Chemistry and Biochemistry, San Francisco State University, San Francisco, California 94132
  • 2Department of Chemistry and Biochemistry, University of California, Santa Cruz, Santa Cruz, California 95064

A chemical library containing 474 organic extracts has been applied to an image-based anticancer screening using HeLa cells. This screening identified 41 strains that showed potent cytotoxic effects against HeLa cells. Based on the bioassay-guided fractionation, two new meroterpenoids (1 and 2) were isolated from one of the active strains, Streptomyces sp. CP26 – 58, together with the known tetronasin (3). The structures of the two new compounds possessing an unprecedented six-fused ring system were firmly assembled by comprehensive 1D and 2D NMR analysis. In addition, their absolute configurations were deduced based on ab intio electronic circular dichroism (ECD) spectral calculations.