WS-7528, A NEW ISOFLAVANONE WITH ESTROGEN ACTIVITY ISOLATED FROM STREPTOMYCES SP. NO. 7528

TAXONOMY, FERMENTATION, ISOLATION, PHYSICO-CHEMICAL PROPERTIES AND BIOLOGICAL ACTIVITIES

Abstract

WS-7528, produced by Streptomyces sp. No. 7528, was extracted from cultured broth, purified by solvent extraction followed by chromatography on silica gel and then isolated as pale yellow powder (C₁₆H₁₄O₅, mp 95-98°C). WS-7528 inhibited estrogen binding to its receptor protein in rat uterine cytosol. The IC₅₀ value of WS-7528 for partially purified rat uterine cytosol receptor was 5.7×10^-8M.
This compound was found to induce the growth of the estrogen dependent cell line MCF-7.
WS-7528 was tested orally and subcutaneously in immature rats to confirm its effect on the growth of the uterus.
WS-7528 has also weak anti-inflammatory activity on the carrageenin paw edema of the rat model.