WS-9659 A AND B, NOVEL TESTOSTERONE 5α-REDUCTASE INHIBITORS ISOLATED FROM A STREPTOMYCES

I. TAXONOMY, FERMENTATION, ISOLATION, PHYSICO-CHEMICAL CHARACTERISTICS

Abstract

WS-9659 A and B, produced by Streptomyces sp. No. 9659, were extracted from cultured broth, purified by solvent extraction followed by chromatography on silica gel and then isolated as prisms (C₂₂H₂₄N₂O, mp 161-162°C, C₂₂H₂₃N₂OCl, mp 152-153°C). WS-9659 A and B have testosterone 5α-reductase inhibitory activity. The IC₅₀ values of WS-9659 A and B for partially purified rat prostate testosterone 5α-reductase were 5.0 × 10^-7 M and l.0× 10^-5 M, respectively.