Penicellide, a nonpeptide calpain inhibitor, produced by Penicillium sp. F60760

Abstract

Penicillide, having a 5H,7H-dibenzo[b,g][1,5] dioxocin-5-one skeleton, was isolated from the culture broth of Penicillium sp. F60760 as a nonpeptide inhibitor of calpain, a calcium-activated papain-like protease. The IC50 value for the effect of penicillide against m-calpaln was 7.1 μM. However, penicillide did not inhibit papain at a concentration of 200 μM. These results suggest that penicillide is a new class of nonpeptide calpain inhibitor having an eight membered lactone ring.