Synthesis of new hetero- and carbocyclic aromatic amides of glycyrrhizic acid as potential anti-HIV agents

Members of a new group of di- and trisubstituted amides of glycyrrhizic acid (GA), the major component of licorice root extract, were synthesized; derivatives contained fragments of heterocyclic and aromatic amines (2-aminopyridine, 4-aminopyridine, 5-aminouracil, sulfadimezine, sulfapyridazine, and L-histidine methyl ester) using the dicyclohexylcarbodiimide method. Amides of GA containing 2-aminopyridine and 5-aminopurine residues had anti-HIV-1 activity in MT-4 cell cultures. The index of selectivity (IS) of the amide of GA with 5-aminouracil was, using various parameters, from 27.73 to 277.32, exceeding values for GA (from 4.45 to 24.0).