New tertiary alkaloids with a 4-quinolone skeleton, (±)-ribalinine (3b), (-)-ribalinidine (3c), (±) and (+)-ribaline (2b), have been obtained from Balfourodendron riedelianum. During isolation, 3c and 3b were found together with the quaternary alkaloidal fraction. The structure elucidations were in part based on spectrometric data. Furthermore, 2b and 3c were chemically correlated with the known ribalinium whilst the structure of 3b was confirmed by total synthesis. The configuration of 3c is S as determined by the Korean's method. © 1973.