ABSTRACT
Complete hydrogen saturation of the indolizine system produces the indolizidine (octahydroindolizine) heterocyclic ring system. Swainsonine, the first water-soluble, polyhydroxylated indolizidine to be reported, was first isolated from, and named after, the toxic Australian legume Swainsona canescens. The potential medical uses of swainsonine have been extensively studied and well reviewed. Briefly, however, swainsonine has potential as a modulator of the immune system as a consequence of its ability to stimulate interleukin 2 production by T-helper cells, and consequent proliferation of T-lymphocytes. It is also effective as an anti-metastasis agent, inhibiting the spread of some tumors, possibly due to its activity in altering oligosaccharide processing by inhibiting complex glycosidation of glycoproteins. As with the glycomimetic swainsonine and related alkaloids, the biological activities of castanospermine and related indolizidines also involve the inhibition of glycosidases.
