Two new bis-diterpenoid alkaloids from Aconitum weixiense

Further investigation on the roots of Aconitum weixiense led to the isolation of two new bis-diterpenoid alkaloids, named as weisaconitines E and F (1-2), which were elucidated by IR, HR-ESI-MS, 1D- and 2D-NMR analyses. Their structures are characterized as denudatine-atisine-type bis-diterpenoid alkaloids.