Two lanostane triterpenoids with α -glucosidase inhibitory activity from the fruiting bodies of Ganoderma weberianum .

A new oxygenated lanostane-type triterpenoid, 20 S ,24 S -epoxy-lanosta-7,9(11)-dien-3 β ,15 α ,25 R ,26-tetraol ( 1 ), together with three known compounds ( 2 - 4 ) were isolated from the fruiting bodies of Ganoderma weberianum . Extensive NMR spectrometry and HRESIMS analysis, as well as NMR and ECD calculations elucidated the structure of the new compound. 27-nor-3 β -hydroxylanosta-7,9(11),23 E -trien-25-one ( 2 ) showed superior α -glucosidase inhibitory activity with IC ₅₀ value of 122.1 μM to that of positive control acarbose (304.6 μM).