Alkaloid extracts from Baptisia australis leaves, analyzed by capillary gas chromatography and gc/ms, were shown to contain sparteine (1), lupanine (6), cytisine (3), N-methyleytisine (2), anagyrine (8), 17-oxosparteine (11), 13-hydroxyanagyrine (10), 5,6-dehydrohipanine (4), tinctorine (7) (new for Baptisia), isotinctorine (5) (new alkaloid) and 13-acetoxyanagyrine (9) (new alkaloid). The alkaloid content of cell suspension cultures was three orders lower than that of the differentiated plants; lupanine figured as the only alkaloid. A biogenetic pathway with lupanine biosynthesis as the central part, from which the α-pyridone alkaloids derive via 5,6-dehydrolupanine (4), is discussed. © 1981, American Chemical Society. All rights reserved.