Natural Occurrence, Synthesis and Biological Applications of Spermidine Alkaloids

Spermidine alkaloids are polyaminated macrocycles containing a lactam ring, which are biosynthetically derived from L-Orn or L-Arg via putrescine intermediates. The presence of these polyamines in nature is very limited, occurring in only a few plant families, and therefore the isolation of spermidine alkaloids serves chemotaxonomic purposes. The interest in the isolation and synthesis of these alkaloids also results from the structural complexity and broad range of bioactivity attributed to these macrocyclic structures.