Anti-cancer and anti-inflammatory new vakognavine-type alkaloid from the roots of Aconitum carmichaelii

Vakognavine-type alkaloids are a rare kind of diterpenoid alkaloid isolated from Delphinium and Aconitum species. During our research on the chemical constituents of the roots of Aconitum carmichaelii, a new vakognavine-type alkaloid (1) along with a known vakognavine-type alkaloid, trifoliolasine E (2), and two known hetisine-type alkaloids (3 and 4) were obtained. The structures were elucidated by a combination of high resolution ESI-MS, 1D and 2D NMR spectra. Compound 1 showed strong inhibitory effects on HT-29, SGC-7901, and HepG2 cell lines with IC50 values of 0.948, 0.983, and 3.645 μM, respectively, while trifoliolasine E (2) exhibited moderate activities. Compound 1 was also found to dose-dependently inhibit the activity of cyclooxygenase-2 (COX-2) with an IC50 value of 29.75 μM. To the best of our knowledge, this is the first report on the bioactivity of vakognavine-type diterpenoid alkaloids.