Isoquinoline alkaloid N-oxides from Thalictrum simplex

The new aporphine alkaloid, (+)-thalicsimidine N-oxide, was found together with the known aporphines, (+)-thalicsimidine, (+)-ocoteine, (+)-preocoteine and preocoteine N-oxide. Both novel phenanthrene alkaloid oxidation products, thalihazine N-oxide and N-hydroxy-northalicthuberine, were isolated together with the known thalihazine and northalicthuberine. The structures of the aporphine and phenanthrene alkaloids as well as their N-oxides were established from spectral analyses.