Euphorpekone A (1) and euphorpekone B (2), two new diterpenoids, 3β-hydroxy-25-methyloxylanosta-8,23-diene, a new triterpenoid (3), together with a known triterpenoid, 3β,25-dihydroxylanosta-8,23-diene (4), were isolated from Euphorbia pekinensis Rupr. Their structures were elucidated on the basis of UV, IR, 1D ((1)H, (13)C, NOE) and 2D ((1)H-(1)H COSY, HSQC, HMBC) NMR, HR-ESI-MS, X-ray diffraction analysis, and CD method.
Keywords: Euphorbia pekinensis; Euphorbiaceae; diterpenoid; triterpenoid.