Metabolic products of microorganisms. 261 obscurolides, a novel class of phosphodiesterase inhibitors from streptomyces: I. Production, isolation, structural elucidation and biological activity of obscurolides a1 to a4

Abstract

A novel class of butyrolactones, named obscurolides, was isolated from the culture filtrate of Streptomyces viridochromogenes by chemical screening methods. The structural elucidation of the obscurolides A1 to A4 (1~4) is described. The carboxy group of the 4-aminobenzoic acid moiety of obscurolide A1 (1) is reduced in the other compounds. The isolated natural products have been proved to be diastereomeric mixtures by a partial racemization at C-7 which belongs to an allylic alcohol system. The obscurolides showed a weak inhibitory activity against calcium/calmodulin-dependent and independent phosphodiesterases from bovine. © 1992, JAPAN ANTIBIOTICS RESEARCH ASSOCIATION. All rights reserved.