GPR120 is a promising target for the treatment of type 2 diabetes (T2DM), which is activated by free fatty acids (FFAs) and stimulates the release of glucagon-like peptide-1(GLP-1). GLP-1, as an incretin, can enhance glucose-dependent secretion of insulin from pancreatic beta cells and reduce blood glucose. In this study, a series of novel GPR120 agonists were designed and synthesized to improve the stability and hydrophilicity of the phenylpropanoic acid GPR120 agonist TUG-891. Compound 11b showed excellent GPR120 agonistic activity and pharmacokinetic properties, and could reduce the blood glucose of normal mice in a dose-dependent manner. In addition, no hypoglycemic side effects were observed even at a dose of 100 mg/kg. Moreover, 11b showed good anti-hyperglycemic effects in diet-induced obese (DIO) mice. Molecular simulation illustrated that compound 11b could enter the active site of GPR120 and interact with ARG99. Taken together, the results indicate that compound 11b might be a promising drug candidate for the treatment of T2DM.

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.

Diabetes mellitus (DM) is a common metabolic disease that poses a severe threat to human health. Despite a range of therapeutic approaches, there remains a lack of effective and safe therapies with the existing drugs. Therefore, there is an urgent need to develop novel, effective, and safe therapeutic strategies for DM. Free fatty acid receptor 4 (FFAR4), also known as GPR120, is a member of the G protein-coupled receptor family, which has received considerable attention as an attractive new therapeutic target for treating DM. In the present study, based on the structure of TUG-891, which has excellent activity and selectivity, a series of novel FFAR4 agonists was designed by replacing the phenylpropanoic acid β position carbon atom with an oxygen atom, while replacing the linking oxymethylene with an amide-linking group. The target compounds were evaluated for FFAR4 agonistic activity, and the preferred compounds were evaluated for selectivity, oral glucose tolerance in normal ICR mice, antidiabetic activity in diet-induced obese (DIO) mice, pharmacokinetic properties in ICR mice and molecular modeling studies. The results showed that compound 10f possessed excellent FFAR4 agonistic activity and selectivity, significantly improved glucose tolerance in normal ICR mice, lowered blood glucose and promoted insulin secretion in a dose-dependent manner in DIO mice, and showed favorable pharmacokinetic properties. These results indicate that compound 10f may be a promising compound that deserves further structure–activity relationship and pharmacological studies for the development of antidiabetic drugs.