WS79089A, B and C, new endothelin converting enzyme inhibitors isolated from Streptosporangium roseum. No. 79089. Taxonomy, fermentation, isolation, physico-chemical properties and biological activities.

WS79089A, B and C, which are novel endothelin converting enzyme (ECE) inhibitors have been isolated from the fermentation broth of Streptosporangium roseum No. 79089. These inhibitors were purified from an acetone extract of whole culture broth followed by Silicar CC-4 column chromatography and HPLC. WS79089A, B and C showed highly selective ECE inhibition activity with IC50 values of 0.73μM 0.14μM and 3.42μM, respectively. On the basis of spectroscopic and chemical evidence, the tentative structures of WS79089A, B and C have been proposed, they have benzo[a]naphtacen chromophores.