Isolation and Characterization of Swainsonine from Texas Locoweed (Astragalus emoryanus)

Abstract
Swainsonine (1,2,8-trihydroxyoctahydroindolizine) was isolated from locoweed (Astragalus emoryanus) that grows in Texas. Using a biological assay as a measure of activity and purity, a relatively straightforward purification of the compound is described. The purified material was a potent inhibitor of jack bean α-mannosidase and also of glycoprotein processing. The positive ion electron impact mass spectra of this compound was identical to that of authentic swainsonine. Nuclear magnetic resonance analysis also confirmed that the material was swainsonine.