Castanospermine-obtained from the seeds of the Australian leguminous tree Castanospermum australe A. Cunn. (Leguminosae) (Moreton Bay Chestnut)

A. Castanospermine

Biological Source It is obtained from the seeds of the Australian leguminous tree Castanospermum australe A. Cunn. (Leguminosae) (Moreton Bay Chestnut).

Chemical Structure

[1S-(1α, 6β, 7α, 8β, 8aβ]-Octahydro-1, 6, 7, 8-indolizinetetrol; (C₈H₁₅NO₄). It is a polyhydroxy alkaloid.

Isolation The isolation of the naturally occurring (+)-form of castanospermine from the seeds of the Australian leguminous tree has been duly accomplished.*

Characteristic Features

1. The crystals obtained from aqueous ethanol have mp 212-215°C (decomposed).

2. Its specific optical rotation is [α]_D²⁵  +79.7^o (C = 0.93 in water); and dissociation constant pK 6.09.

Uses Its has demonstrated activity against the AIDS virus HIV, by virtue of their ability to inhibit glyosidase enzymes involved in glycoprotein biosynthesis. However, the glycoprotein coating seems to be vital for the proliferation of the AIDS virus.