Anicequol, a novel inhibitor for anchorage-independent growth of tumor cells from Penicillium aurantiogriseum Dierckx TP-F0213

A novel inhibitor for anchorage-independent growth of tumor cells was isolated from the culture broth of a fungal strain. The producing strain TP-F0213 was identified as Penicillium aurantiogriseum Dierckx based on the taxonomic study. The compound designated anicequol was obtained by solvent extraction, HP-20 and silica gel chromatographies and recrystallization. The planar structure was elucidated by NMR analysis to be 16-acetoxy-3,7,11-trihydroxyergost-22-en-6-one. The absolute configuration was determined by the X-ray analysis of 3,7-bis-p-bromobenzoyl derivative. The carbon skeleton of anicequol has the same absolute configuration as ergostane and the configurations of substituents are 3beta,5alpha,7beta,11beta, 16beta and 24S. Anicequol inhibited the anchorage-independent growth of human colon cancer DLD-1 cells with the IC50 of 1.2 muM whereas the IC50 against anchorage-dependent growth was 40 muM.