**Abstract**

In the complex pharmacognostic studies of three species of the genus *Hedysarum* L., we have developed a method for quantitative determination by UV spectrophotometry, HPLC, and capillary electrophoresis of the sum of xanthones in terms of mangiferin. The technique takes into account the basic physicochemical properties of xanthones; is characterized by reproducibility, high accuracy, and simplicity; and allows conducting both a screening assessment of various raw materials containing mangiferin derivatives and standardization of the prepared vegetable raw materials. The developed methods are tested on the aboveground organs of *Hedysarum* species, which are collected and dried by taking into account the rules and requirements for the preparation of medicinal raw materials. As a result, it was found that the greatest quantitative content of the sum of xanthones in terms of mangiferin is distinguished by the grass *H. caucasicum* M. Bieb. (0.62 0.021%). For the first time, morphological-anatomical diagnostic signs of the species *Hedysarum caucasicum M. Bieb*., *Hedysarum daghestanicum Rupr. ex Boiss*., *Hedysarum grandiflorum Pall*. are necessary for standardization of medicinal vegetal raw materials. The results show the prospect of further investigation of *Hedysarum* as an additional source of mangiferin.

**Keywords:** *Hedysarum*, xanthones, mangiferine, antiviral therapy
