Alkaloids of Rhazya stricta Decaisne: studies on rhazinaline and geissoschizine

Abstract

Chemical investigation of the basic principles of the leaves of Rhazya stricta Decaisne led to the isolation of a number of indolic bases. The studies on two of these, viz., rhazinaline and geissoschizine are described. Rhazinaline, a new alkaloid, has been characterised as 16-formyl-16-epistrictamine. A detailed spectroscopical study of geissoschizine, which had not been previously isolated from a plant source, was carried out confirming the previous structural assignment. The isolation of this alkaloid from a plant source is important from a biogenetic viewpoint, since geissoschizine is one of the key preformed intermediates in the biosynthesis of C₁₉-C₂₀ indole alkaloids.