Three New Lactone-Type Diterpenoid Alkaloids from Aconitum rotundifolium Kar. & Kir.

Three new lactone-type C-19-diterpenoid alkaloids, rotundifosines A C (1 - 3) along with two known diterpenoid alkaloids, heterophyllidine (4) and chellespontine (5) were isolated from the whole plant of Aconitum rotundifolium Kar. & Kir. Their structures were established on the basis of extensive spectroscopic analysis, including 1D and 2D NMR experiments. Compounds 1 - 3 were evaluated for cytotoxicity against MCF-7, MDA-MB-231, 786-0 and HepG2 human cancer cell lines.