Lupine Alkaloids

Abstract

The alkaloids of lupine (Lupinus spp.) comprise about thirty different compounds with structural resemblances, and, apparently, biochemical interrelationships. These compounds, often called “lupine alkaloids”, are not completely confined to this genus but are well-known in related Leguminosae genera such as Baptisia, Cytisus, and Genista and are also found sporadically in other plant families. All contain one or two quinolizidine ring systems and may therefore be called quinolizidine alkaloids. Some examples are given below to illustrate the major structural types. It will be noted that (−)-cytisine and (+)-sparteine have the same absolute configuration of the methylene bridge. Okuda et al. [1] have pointed out that customarily a series of lupine alkaloids with the same configuration occur together in the same plant. Thus, plants having (+)-sparteine as a rule contain (−)-cytisin, (−)-baptifoline, (−)-lupanine, and (−)-thermopsine. Plants having (−)-sparteine will have the enantiomorphic series. An exception is G. aetnensis where (+)- and (−)-sparteine are found in different parts of the same plant (see below). These observations on co-occurrence presumably indicate that members of the same stereochemical series are also biosynthetically related.

Sweet is the broom flower, but yet sour enough;

And sweet is moly, but his root is ill;

So, every sweet, with sour is tempered still.

Sweet is the Rose, Edmund Spenser