Three new alkaloids, ryosenamine (I), ryosenaminol (II) and ibukinamine (III), were isolated from Aconitum ibukiense Nakai (ibuki torikabuto). The structure of ryosenamine (I) was elucidated as 1-deoxyhypognavine by spectroscopical study and determined by its correlation with ryosenaminol (II), the structure of the latter being confirmed by X-ray analysis. The structure of ibukinamine (III) was also determined by X-ray analysis.
