Sparteine

Sparteine is a class 1a antiarrhythmic agent; a sodium channel blocker. It is an alkaloid and can be extracted from scotch broom. It is the predominant alkaloid in Lupinus mutabilis, and is thought to chelate the bivalents calcium and magnesium. It is not FDA approved for human use as an antiarrhythmic agent, and it is not included in the Vaughn Williams classification of antiarrhythmic drugs.

It is also used as a chiral base in organic chemistry, and as a ligand in organic chemical synthesis.

Biosynthesis

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. The mechanism of formation has been studied enzymatically, as well as with tracer experiments, but the exact route of synthesis still remains unclear.