Constituents of West African medicinal plants. XXI. Tiliafunimine, a new imino bisbenzylisoquinoline alkaloid from Tiliacora funifera.

Tiliacora funifera (Menispermaceae) is a woody climber of Ghana and West Africa that has been used natively as a medicinal in the treatment of numerous ailments. Chromatography of an extract of the leaves of T. funifera afforded tiliafunimine (13) whose ir, uv, nmr, and mass spectra were characteristic of a trimethoxylated phenolic iminobisbenzylisoquinoline alkaloid. Reduction of tiliafunimine with sodium borohydride afforded the dihydro-derivative (14) which upon treatment with formalin gave thalrugosine (12). The final structural assignment of tiliafunimine (13) as an iminobisbenzylisoquinoline alkaloid was made by nmr and mass spectral considerations. Other alkaloids isolated from the same extract include the bisbenzylisoquinoline bases isotetrandrine (11) and thalrugosine (12).