We have investigated the alkaloidal constituents of the root of an Aconitum species collected at Mt. Mineoka (Chiba Pref.). In addition to the known nine compounds, i.e. mesaconitine, hypaconitine, aconitine, deoxyaconitine, isotalatizidine, 14-O-acetyltalatizamine, neoline, takaosamine, and ignavine, a new diterpene alkaloid was isolated. The structure of this new base was established to be 15-α-hydroxyneoline by the spectroscopic evidence and by the partial synthesis from neoline.
