The roots of Stemona japonica contain this alkaloid as a minor constituent,
occurring with its isomer, isostemonamine. The base is separated from the
accompanying alkaloids by chromatography and countercurrent distribution
methods. The structure has been determined by X-ray crystallographic analysis
of the hydrochloride dihydrate which forms triclinic crystals, space group PI,
having dimensions of a = 14.62, b = 9.29 and c = 7.74 A. The structure was
solved by a modified Fourier technique based upon the heavy-atom positions.
Iizuka et ai., J. Chem. Soc., Chem. Commun., 4, 125 (1973)
