Optimisation of the Method of Obtaining the Monoammonium Salt of Glycyrrhizic Acid from the Roots of the Ural Licorice (<i>Glycyrrhiza uralensis</i> Fisher) of Siberian Populations
We optimised the method of obtaining the monoammonium salt of glycyrrhizic acid (glycyram) from the roots of the Ural licorice (Glycyrrhiza uralensis Fisher) of Siberian populations. The method includes the following stages: extraction of the roots with a 0.5 % solution of NH4OH, precipitation of the sum of acids with the help of concentrated H2SO4, subsequent re-extraction with a 1 % solution of H2SO4 in acetone, salting out the triammonium salt of glyccyrrhizic acid using a 25 % NH4OH solution, transformation of this salt into the monoammonium salt (glycyram) by crystallization from glacial СН3СООН. Using this method, one may obtain the samples of glycyram with a purity of 85.2-87.5 % (according to the HPLC data). The glycyrrhizic acid content in the investigated samples of licorice roots is 2-4 %.