Deacetylravidomycin M, a new inhibitor of IL-4 signal transduction, produced by Streptomyces sp. WK-6326. I. Taxonomy, fermentation, isolation and biological activities

Abstract

Streptomyces sp. WK-6326, a soil isolate, was found to produce an inhibitor of interleukin (IL)-4 signal transduction. Two structurally related compounds, a novel one designated deacetylravidomycin M and the known deacetylravidomycin, were isolated from the culture broth by solvent extraction, silica gel column chromatography and HPLC. Deacetylravidomycin M inhibited IL-4-induced CD23 expression in U937 cells without any cytotoxic effect, whereas deacetylravidomycin showed no inhibitory activity.