[20(22) E ]-Lanostane Triterpenes from the Fungus Ganoderma australe .

Twelve new lanostane triterpenoids ( 1 - 5 , 7 - 13 ) were isolated from the fruiting bodies of the fungus Ganoderma australe . The structures of the new compounds were elucidated by extensive 1D and 2D NMR, and HRESIMS spectroscopic analysis. All the triterpenes are featured by 20(22) E configurations which are uncommon in the Ganoderma triterpene family. The absolute configuration of the C-25 of compounds 1 , 2 , and 6 were determined by the phenylglycine methyl ester (PGME) method. A postulated biosynthetic pathway for compound 1 was discussed. This study opens new insights into the secondary metabolites of the chemically underinvestigated fungus G. australe .