Triterpenoids from Euphorbia pulcherrima with inhibitory effects on osteoclastogenesis

Abstract Three new compounds ( 1 – 3 ), euphorimaoid A ( 1 ), euphorimaoid B ( 2 ), 1 α -hydroxy-3 β -acetoxy-olean-9,12-diene ( 3 ), two firstly isolated natural products 3 β -acetyloxy-olean-13(18)-en-12-one ( 4 ) and 18,19-epoxyolean-3 β -ol acetate ( 5 ), together with 13 known compounds ( 6 – 18 ) have been identified from the aerial parts of Euphorbia pulcherrima Willd. Structures of compounds 1 – 5 were elucidated by comprehensive spectroscopic analysis. The absolute configuration of euphorimaoid A ( 1) was established using single crystal X-ray diffraction analysis. All the isolates were evaluated for their inhibition of osteoclastogenesis in BMMs. Among them, compounds 7 and 10 showed significantly inhibition in a concentration-dependent manner.