PF1092A, B and C, new nonsteroidal progesterone receptor ligands produced by Penicillium oblatum .1. Taxonomy of producing strain, fermentation, isolation and biological activities

Three new nonsteroidal progesterone receptor ligands, PF1092A, B and C, have been isolated from Penicillium oblatum. They were purified from the solid cultures of rice media using ethyl acetate extraction, silica gel and Sephadex LH-20 column chromatographies, and crystallization. All three ligands competitively inhibited [H-3]-progesterone binding to porcine uteri cytosol preparations with IC50 of 3.0 x 10 nM (PF1092A), 2.2 x 10(2) nM (PF1092B) and 2.2 x 10(3) nM (PF1092C).