sentences:  Sparteine is a lupin alkaloid containing a tetracyclic bis-quinolizidine ring system derived from three C5 chains of lysine, or more specifically, L-lysine.The first intermediate in the biosynthesis is cadaverine, the decarboxylation product of lysine catalyzed by the enzyme lysine decarboxylase (LDC).Three units of cadaverine are used to form the quinolizidine skeleton.