Structural basis for the agonist action at free fatty acid receptor 1 (FFA1R or GPR40).

G-protein-coupled receptor 40 (GPR40) was recently identified as an interesting target for treatment of type 2 diabetes. The high level of expression in pancreatic beta cells and the dependence of glucose on stimulating the secretion of insulin led to great excitement in this field. The identification of this target was followed by the development of a series of agonists with great potential for the treatment of diabetes. All known agonists have the presence of a pharmacophoric carboxylic acid group in their structure, which makes several polar interactions at the binding site of this receptor. In this report, we provide a review of the structure-activity relationships of GPR40 agonists with a focus on the main strategies of medicinal chemistry used to develop each one of the main structural patterns exploited for this purpose. Additionally, we provide a general model for the design of GPR40 ligands that can help researchers to follow up some strategies and implement them in the development of novel agonists of this receptor.