Synthesis and biological activity of new 18β-glycyrrhetinic acid derivatives

In an attempt to find out new, potent and safe anti-inflammatory molecules and as a contribution in the chemistry of triterpenes, a series of 18β-glycyrrhetinic acid (GTA) derivatives (4a–j, 5a–e, 7–9, 11–13) were synthesized and evaluated as anti-inflammatory agents using carrageenan induced rat paw edema method. The synthesized derivatives proved superior anti-inflammatory activity to GTA. Moreover, some of the produced derivatives demonstrated higher effect than prednisolone and indomethacin. This remarkable anti-inflammatory effect was combined with no detrimental effect on the gastrointestinal tract (GIT) of the test rats. All of the synthesized compounds were characterized by NMR spectroscopy and high-resolution ESI mass spectrometry.