title: Letter: Nonbasic aporphine alkaloids from Liriodendron tulipifera L.
mesh_terms: D000470:Alkaloids / Q000302:isolation & purification*; D001060:Aporphines / Q000302:isolation & purification*; D055598:Chemical Phenomena; D002621:Chemistry; D010946:Plants, Medicinal / Q000032:analysis*
chemical_list: D000470:Alkaloids; D001060:Aporphines