Endothelin-binding inhibitors, BE-18257A and BE-18257B. I. Taxonomy, fermentation, isolation and characterization

Two endothelin (ET)-binding inhibitors, BE-18257A and BE-18257B, which antagonized 125I-ET-1 binding to a porcine aortic smooth muscle membrane, were isolated from the mycelium of a strain of Streptomyces misakiensis. These binding inhibitors were extracted with methanol from mycelium and purified by HPLC.