Calvatianone, a Sterol Possessing a 6/5/6/5-Fused Ring System with a Contracted Tetrahydrofuran B-Ring, from the Fruiting Bodies of Calvatia nipponica.

Calvatia nipponica is an extremely rare mushroom with a limited number of studies on its chemical components and biological activities published. Here we report the isolation of a novel sterol, cal...