Stem barks of Guatteria discolor have yielded 18 alkaloids among which ten are new: guadiscine (13), guadiscoline (14), and guadiscidine (15), belonging to the new class of aporphine alkaloids (7,7-dimethylaporphinoids); guacoline (16) and guacolidine (17), belonging to a new class of aporphines (7-hydroxy 7-methyl aporphinoids); saxoguattine (18), a dimethylaminoethylbenzile; discoguattine (10), isocalycinine (11), and oxoisocalycinine (12) (aporphinoids); and N-oxyatherosperminine (7) (phenanthrene). The other alkaloids are known: corypalmine (1), discretamine (2), discretine (3), 10-demethyldiscretine (4), argentinine (5), atherosperminine (6), puterine (8), and O-methylpukateine (9).