Glycyrrhizic Acid Derivatives as New Antiviral and Immune Modulating Agents

The search for new drugs to treat viral infections and immune deficiencies of various etiologies is still one of the most important tasks of medicinal chemistry, pharmacy, and medicine due to the widespread prevalence of a number of socially dangerous viral infections. This review focuses on the chemical modification of Glycyrrhizic acid (Gl), the main component of licorice root, which is currently a leading natural glycoside that is considered to be promising for the development of new antiviral agents. The review presents the results of studies conducted over the past 15 years to obtain a library of Gl acid derivatives for biological studies and to search for leader compounds. The synthesis of new biologically active derivatives and analogues (conjugates with amino acids and dipeptides, amino sugars, licorice triterpene acids conjugates with amino sugars, saponins and mono glycosides, and heterocyclic amides) was conducted, and their antiviral and immune modulating properties were studied. Potent inhibitors of HIV, SARS CoV, Epstein-Barr, and influenza A/H1N1 viruses and the stimulators of primary immune response were found among the Gl derivatives and analogues that were produced.