Process for preparing mangiferin

摘要

A process for preparing mangiferin from plants of the genus of Hedysarum (Hedysarum alpinum L., Hedysarum flavescens Rgl. et Schmalh) comprising extraction of xanthone glycosides from the aerial portion of the plants by means of a mixture acetone-water at a volume ratio of the mixture components of 1:0.5-2 respectively; the resulting extract is evaporated, the evaporated extract is filtered. To the filtered evaporated extract sulphuric acid is added to a pH of from 2 to 4, heated at reflux and filtered. The thus-prepared extract is treated with a non-polar organic solvent with the formation of two layers, wherefrom the upper aqueous layer contains xanthone glycosides. This upper layer is treated with butanol with the formation of two layers, wherefrom the upper layer comprises a solution of xanthone glycosides in butanol. This upper butanolic layer is evaporated. The precipitated mangiferin is separated and recrystallized.