Thalprzewalskiinone, a new oxobenzylisoquinoline alkaloid from Thalictrum przewalskii

A novel oxobenzylisoquinoline alkaloid, thalprzewalskiinone (1), was isolated from the roots of Thalictrum przewalskii, and its structure was established via spectroscopic analysis. Five other alkaloids were isolated: the protoberberines pseudocoptisine and berberine, the aporphines (+)-N-methylnantenine and (+)-magnoflorine, and the simple isoquinolone N-methyl-6,7-dimethoxyisoquinolone. Isovanillin was also isolated from this extract.