Ws009 a and b, new endothelin receptor antagonists isolated from streptomyces sp. no. 89009: I. Taxonomy, fermentation, isolation, physico-chemical properties and biological activities

Abstract

WS009 A and novel endothelin receptor antagonists, have been isolated from the fermentation broth of Streptomyces sp. No. 89009. These antagonists were purified from the culture filtrate followed by Diaion SP-207, DEAE Toyopearl column chromatography and HPLC. WS009 A and B showed selective activity in an endothelin receptor binding assay with IC50 of 5.8 × 10-6m and 6.7 × 10-7m, respectively. On the basis of spectroscopic and chemical evidence, the structures of WS009 A and B have been established as 1 and 3, and are highly hydroxylated benz[a]anthraquinone chromophores. © 1992, JAPAN ANTIBIOTICS RESEARCH ASSOCIATION. All rights reserved.