“…The evidence suggests that lysine, C6N2, via cadaverine, 'On leave from the Department of Chemistry, University of Warsaw, 02-093 Warsaw, Poland. Incorporation studies with deuterium-labelled samples of lysine (3) and cadaverine (3,(18)(19)(20)(21) into (-)sparteine (3, 18, 21) (I), (+)sparteine (19) (the enantiomer of I), (+)lupanine (3,18,20,21) 2, and (+)-13a-hydroxylupanine (20,21) (3) throw light on the mode of incorporation of the C5N unit and define the stereochemistry of some of the steps in the biosynthetic sequence from lysine into cadaverine and thence into the alkaloids.…”