Three new sesquiterpenoids from the stems of Strophanthus divaricatus

Abstract Three new aromadendrane-type sesquiterpenoids (1–3) and five known compounds (4–8) were isolated from the stems of Strophanthus divaricatus. Their structures were determined by spectroscopic methods including HR-ESI-MS, 1D and 2D NMR. The absolute configurations of 1–3 was determined by comparison of the experimental and computed ECD spectra. Neridienone A (6) exhibited significant cytotoxicity against human cancer cell lines BEL-7402, SGC-7901, K562, A549, and HeLa with IC50 values of 3.30 ± 0.01, 2.25 ± 0.01, 2.02 ± 0.03, 1.55 ± 0.01, 4.73 ± 0.07 μM, respectively.