BACKGROUND OF THE INVENTION
Castanospermine is an alkaloid having the following formula: ##STR1## Systematically, this compound is named (1S,6S,7R,8R,8aR)-1,6,7,8-tetrahydroxyindolizidine.
The isolation of of this compound from Castanospermum australe has been described by L. D. Hohenshutz, et al.,