Euphorfiatnoids A−I: Diterpenoids from the roots of Euphorbia fischeriana with cytotoxic effects

Nine previously undescribed diterpenoids, euphorfiatnoids A-I, together with seven known diterpenoids, were isolated from the roots of wild Euphorbia fischeriana. Their structures were elucidated by the interpretation of HRESIMS, UV, and NMR data. Their configurations were determined by electronic circular dichroism (ECD) spectroscopy analysis and the structure of euphorfiatnoid A was confirmed by X-ray crystallography. To further understand the antitumor effects of E. fischeriana, we tested the cytotoxicity of these compounds against H460, HepG2, and MCF-7 cell lines in vitro using MTT assays. Euphorfiatnoid B exhibited the most promising inhibitory effect against H460 cells with an IC50 value of 9.97 μM. Euphorfiatnoid A and C also exhibited moderate cytotoxicity against HepG2 cells with IC50 values of 11.64 and 13.10 μM, respectively.