Studies on the constituents of aconitum species. IV. On the components of Aconitum japonicum THUNB.

Two new alkaloids, aljesaconitine A and aljesaconitine B, and six known alkaloids, aconitine, jesaconitine, mesaconitine, neoline, hokbusine A, and delcosine, were isolated from the roots of Aconitum japonicum THUNB. (formerly known as Aconitum subcuneatum NAKAI). The structures of aljesaconitines A and B were determined on the basis of spectral data and derivation from jesaconitine. An acetoxy group at C-8 of an aconitine-type alkaloid was found to be easily changed to an alkoxy group by the use of alcohols such as methanol and ethanol in the extraction procedure. Quantitative determination and the LD50 values of these 8-O-alkyl derivatives are also described.