Seven New Aconitine-Type Diterpenoid Alkaloids from the Roots of Aconitum apetalum

Seven new aconitine-type C₁₉-diterpenoid alkaloids, apetaldines K-Q (1-7), were isolated from the roots of Aconitum apetalum (Huth) B. Fedtsch. Their structures were established on the basis of extensive spectroscopic analyses (HRESIMS, 1D and 2D NMR). Among them, compounds 1 and 2 possess a unique 2-(E)-(2-methylbut-2-enamido)benzoate moiety at the C-18 position. Furthermore, cytotoxic activities of these diterpenoid alkaloids were also evaluated.