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.