RES-701-2, -3 and -4, Novel and Selective Endothelin Type B Receptor Antagonists Produced by Streptomyces sp. I. Taxonomy of Producing Strains, Fermentation, Isolation, and Biochemical Properties.

Abstract

RES-701-2, -3 and -4, novel cyclic peptide endothelin antagonists, were isolated from the culture broths of Streptomyces sp. RE-701 and RE-896, RES-701s selectively inhibited the ET-1 binding to endothelin type B receptor (ETB receptor) with IC50 values ranging from 5 to 20 nM. Taxonomy of the producing strains, fermentation, isolation and biochemical properties of RES-701s are described.