Studies on Steroids. XIII. The Structure of Rhodexin-B and-C.

Abstract

Rhodexin-B, a cardiac glycoside of Rhodea japonica ROTH., was subjected to the Mannich hydrolysis and oleandrigenin (16-acetylgitoxigenin) was obtained as the main product, together with gitoxigenin, dianhydrogitoxigenin, and rhamnose. From these results the existing formulation for the structure of rhodexin-B and-C were corrected to 16-acetylgitoxigenin rhamnoside (II) and 16-acetylgitoxigenin rhamnosido-glucoside (III), respectively. This report constitutes the first example of the Mannich hydrolysis of the glycosides of oleandrigenin linking with a 2-hydroxy sugar.