Terpenoids from Euphorbia helioscopia and Their Cytotoxic Activities against H1975 Cells.

Three previously undescribed diterpenoids, helioscopnoids A-C, and eight known compounds were isolated from the whole plants of Euphorbia helioscopia. Their structures were established by extensive analysis of spectra and data comparison with previous literatures. Among them, compound 4 was identified as 24,24-dimethoxy-25,26,27-trinoreuphan-3ß-ol with revised configurations of C-13, C-14, and C-17 (13R*, 14R*, 17R*). Cytotoxicity assays revealed that all compounds exhibited varying levels of cytotoxicity against H1975 cells, with compound 9 displaying the most potent activity, as indicated by cell viability rates of 18.13 % and 20.76 % at concentrations of 20 µM and 5 µM, respectively. This study expands the understanding of E. helioscopia terpenoids' structural diversity and biological activities, contributing to the exploration of potential therapeutic applications.