Euphatexols A and B, two unusual euphane triterpenoids from the latex of Euphorbia resinifera
Abstract Two unusual euphane triterpenoids, named euphatexols A (1) and B (2) were isolated from the latex of Euphorbia resinifera. Their structures were elucidated based on the extensive analysis of spectroscopic data (HRMS, 1D and 2D NMR) Compound 1 possesses a rare tetrahydrofuran ring formed via C 1 and C 11, which is firstly reported in euphane triterpenoids. Compound 2 represents an unusual 27 nor euphane triterpenoid. Moreover, compounds 1 and 2 showed significant cytotoxic activities against HepG2 cells with 87.0% and 87.4% inhibition rate at 1 mM, respectively.