Terpendoles, Novel ACAT Inhibitors Produced by Albophoma yamanashiensis. I. Production, Isolation and Biological Properties.

A series of new acyl-CoA: cholesterol acyltransferase (ACAT) inhibitors termed terpendoles were isolated from the culture broth of a fungal strain FO-2546 which was proposed to belong to a new genus designated as Albophoma yamanashiensis. Among four structurally related terpendoles, terpendole C showed the most potent ACAT inhibitory activity with an IC50 value of 2.1 microM in an in vitro enzyme assay, followed by terpendoles D (IC50: 3.2 microM), A (15.1 microM) and B (26.8 microM). Evaluation of their ACAT inhibition in the cell assay using J774 macrophages indicated that terpendole D exhibited the highest specificity (cytotoxicity vs. ACAT inhibition) among microbial ACAT inhibitors we discovered so far.