Discovery of Novel and Selective G-Protein Coupled Receptor 120 (GPR120) Agonists for the Treatment of Type 2 Diabetes Mellitus

Diabetes mellitus (DM), a chronic metabolic disorder characterized by high blood glucose, not only poses a serious threat to human life and health, but also places an economic burden on society. Currently available antidiabetic pharmacological agents have some adverse effects, which have stimulated researchers to explore novel antidiabetic agents with different mechanisms of action. G-protein Coupled Receptor 120 (GPR120), also known as free fatty acid receptor 4 (FFAR4), which is activated by medium-chain and long-chain fatty acids, has emerged as an interesting potential target for the treatment of metabolic disorders. Herein, we designed and synthesized a series of novel GPR120 agonists based on the structure of TUG-891, which is susceptible to β-oxidation and loses its GPR120 agonistic activity in vivo. Among the designed compounds, 14d showed excellent agonistic activity and selectivity and could improve glucose tolerance in normal mice in a dose-dependent manner. In addition, the compound 14d displayed good antidiabetic effects in diet-induced obese (DIO) mice and elevated insulin levels. Molecular simulations illustrated that compound 14d could enter the active site of GPR120 and interact with ARG99, which plays an important role in GPR120 activation. Based on these observations, compound 14d may be a promising lead compound deserving of further biological evaluation and structural modifications.