chapter  3
13 Pages

Erythrin Alkaloids

WithA. S. Chawla, V. K. Kapoor

The Erythrina genus comprises 108 species of orange or red-flowered trees, shrubs, and herbaceous plants. The plants are found throughout the tropical and semi-tropical regions of the world. The genus Erythrina (Fabaceae) is a part of the Papilionaceae subfamily of the Leguminosae family. The remarkable curare-like activity of the Erythrina alkaloids has provided the stimulus for the extensive chemical studies on the genus. Moreover, the Erythrina alkaloids were tertiary bases, whereas other alkaloids with curarizing activity were all quaternary salts. The characteristic chemical feature of the Erythrina alkaloids is the presence of a tetracycline spiroamine system, erythrinane. There are some alkaloids isolated from Erythrina species which do not have the characteristic erythrinan skeleton but have a benzylisoquinoline, tetrahydrobenzylisoquinoline, or indole system in them. The occurrence of alkenoid alkaloids is fairly wide in the genus; however, their abundance is usually much less in comparison to dienoid or lactonic alkaloids.