Diterpenoid alkaloids from the roots of Aconitum bulbilliferum.

The phytochemistry study of Aconitum bulbilliferum Hand.-Mazz. is firstly reported. Two C-diterpenoid alkaloids, named bulbilliferines A and B (1 and 2), three C-diterpenoid alkaloids, bulbillifedines A-C (3-5), and twenty known compounds (6-25) were isolated from the roots of A. bulbilliferum. The structures of these compounds were determined by the comprehensive spectroscopic analyses (HRESIMS, IR, 1D and 2D NMR). Among them, bulbilliferine A (1) is a denudatine-type diterpenoid alkaloid bearing a 16, 17-epoxy group. At a nontoxic dose of 10 mg/kg, 14-O-anisoylchasmanine (14) hydrochloride and austroconitine B (17) hydrochloride respectively exhibited the excellent analgesic effects with 83.6 % and 83.1 % inhibitions against acetic acid-induced writhing of mice.