Pannorin, a new 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitor produced by Chrysosporium pannorum.

Pannorin, a naphthopyrone that inhibits 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase, the rate-limiting enzyme in cholesterol synthesis, was isolated from a culture broth of Chrysosporium pannorum M10539 by solvent extraction, Bio-Gel P-6 column chromatography and reverse phase HPLC (Silica ODS). Spectroscopic analyses of the compound yielded 4,8,10-trihydroxy-5-methyl-2H-naphtho[1,2-b]pyran-2-one as the proposed structure. Pannorin inhibited HMG-CoA reductase and in vitro sterol synthesis 50% at a concentration of 160 microM.