Crystalline chemical components of Fomes senex and structure of senexdiolic acid and related compounds

Abstract

The isolation of four new terpenoid (one C30 and three C29) compounds from the fungus Fomes senex and the elucidation of their structures are described. The C30 compound, senexdiolic acid, is shown to be 3β,22-dihydroxy-lanosta-8,24-dien-30-oic acid (Ia), senexonol is 22-hydroxy-31-norlanosta-8,24-dien-3-one (Il), senexdione is the corresponding nor-diketone (Io), and oxidosenexone is 22,25-epoxy-31-norlanost-8-en-3-one (IIe). These compounds have significance for the biosynthesis of sterols.