1992 Volume 45 Issue 1 Pages 74-82
WS-7338 A, B, C and D, novel endothelin receptor antagonists, have been isolated from fermentation broth of Streptomyces sp. No. 7338. These antagonists were purified from the culture mycelium by extraction with acetone, followed by carbon column chromatography and HPLC. Among them, WS-7338 B showed good activity in an endothelin receptor binding assay with an IC50 of2.7×10-7M.