Thalibealine, a Novel Tetrahydroprotoberberine−Aporphine Dimeric Alkaloid fromThalictrum wangii¹

A novel tetrahydroprotoberberine-aporphine dimeric alkaloid, (-)-thalibealine (1), was isolated from the roots of Thalictrum wangiii, and its structure established via spectroscopic analysis. Three other alkaloids were isolated, including the benzyltetrahydroisoquinoline - aporphine dimer (+)-thalmelatidine, the aporphine (+)-magnoflorine, and the protoberberine berberine. This is the first reported isolation of a tetrahydroprotoberberine - aporphine dimer from nature, as well as the first reported isolation of constituents from Thalictrum wangii.