Quantitative determination of the biologically active compounds of licorice (Glycyrrhiza) roots

Introduction. Licorice (Glycyrrhiza glabra L.) and Ural licorice (Glycyrrhiza uralensis Fisch.) are widely used in official medicine. Licorice roots are widely used in the production of a number of medicines. Licorice root raw materials are standardized in terms of the content of glycyrrhizic acid. The main biologically active compounds of licorice also include flavonoids, the major compound of which is licurazide. Given the significant contribution of flavonoids to the biological activity of raw materials and licorice preparations, it is advisable to consider the possibility of determining both glycyrrhizic acid and licurazide. Objective: to develop procedures for quantification of the content of glycyrrhizic acid and licurazide in the licorice roots, using a HPLC method. Material and methods. The materials were the Glycyrrhiza glabra L. and Glycyrrhiza uralensis Fisch. roots harvested in 2018 and 2021 from the plants grown in the Botanical Garden of the Samara Medical University; the commercial samples of plant raw materials (AO «Krasnogorskleksredstva», OOO «Firma KIMA»); the state standard samples (SSSs) of glycyrrhizic acid monoammonium salt (glycyram) (PA 42-0034-00) and licurazide (PA 42-2573-88); a working standard sample of glycyrrhizic acid. Aqueous ethanol extracts were obtained from licorice roots, which were used to quantify the active components by a HPLC method. Results. Procedures were developed to measure the count of glycyrrhizic acid and licurazide in the licorice roots by HPLC. The error in determining the mean levels of glycyrrhizic acid and licurazide in the licorice roots with a 95% confidence probability was ±4.11 and ±4.76%, respectively. The content of glycyrrhizic acid (in terms of glycyram) in the licorice roots ranged from 3.24 to 4.49%; that of licurazide did from 0.200 to 0.321%. Conclusion. The investigation has shown that it is expedient to standardize licorice roots by two indicators: the content of glycyrrhizic acid and the diagnostically significant flavonoid licurazide by a HPLC method in the isocratic elution mode.

Glycyrrhiza glabra L, Glycyrrhiza uralensis Fisch, licorice, Glycyrrhiza glabra L, Ural licorice, Glycyrrhiza uralensis Fisch, standardization, HPLC, glycyrrhizic acid, flavonoids, licurazide