ABSTRACT
Given its role in the mediation of energy and glucose homeostasis, the G-protein-coupled bile acid receptorâ 1 (TGR5) is considered a potential target for the treatment of typeâ 2 diabetes mellitus and other metabolic disorders. By thorough analysis of diverse structures of published TGR5 agonists, a hypothetical ligand-based pharmacophore model was built, and a new class of potent TGR5 agonists, based on the novel 3,4,5-trisubstituted 4,5-dihydro-1,2,4-oxadiazole core, was discovered by rational design. Three distinct synthetic methods for constructing 4,5-dihydro-1,2,4-oxadiazoles and extensive structure-activity relationship studies are reported herein. Compound (R)-54 n, the structure of which was determined by single-crystal X-ray diffraction and quantum chemical solid-state TDDFT-ECD calculations, showed the best potency, with an EC50 value of 1.4â nM toward hTGR5. Its favorable properties inâ vitro warrant further investigation.