(–)-Steviamine is a recently identified member of the polyhydroxylated indolizidine family. Steviamine isolated from the leaves of Stevia rebaudiana (Asteraceae) and other members of the family, swainsonine, castanosperimine, and lentiginosine, are possible antidiabetic, antiviral, and anticancer compounds.
To study steviamine further, Stephen Pyne, University of Wollongong, Australia, and colleagues developed a concise synthesis for this compound as well as analogues 10-nor-steviamine, 10-nor-ent-steviamine and 5-epi-ent-steviamine. The four-step route from a readily accessible L-β-ribofuranose derivative involves an unusual Petasis reaction, a ring-closing metathesis, and a O-mesylate cyclization reaction to generate the nitrogen-containing heterocycles.
All compounds were tested against 12 glycosidases, but showed poor inhibitory activity against most enzymes.
- Concise synthesis of steviamine and analogues and their glycosidase inhibitory activities
N. Jiangseubchatveera, M. E. Bouillon, B. Liawruangrath, S. Liawruangrath, R. J. Nash, S. G. Pyne,
Org. Biomol. Chem. 2013.