Discovery of a potent glucokinase activator with a favorable liver and pancreas distribution pattern for the treatment of type 2 diabetes mellitus

Glucokinase (GK) is an enzyme that plays an important role as a glucose sensor while maintaining whole body glucose homeostasis. Allosteric activators of GK (GKAs) have the potential to treat type 2 diabetes mellitus. To identify novel GKAs, a series of compounds based on a thiophenyl-pyrrolidine scaffold were designed and synthesized. In this series, compound 38 was found to inhibit glucose excursion in an oral glucose tolerance test (OGTT) in mice. Optimization of 38 using a zwitterion approach led to the identification of the novel GKA 59. GKA 59 exhibited potent blood glucose control in the OGTT test as well as a favorable safety profile. Owing to low pancreatic distribution, compound 59 primarily activates GK in the liver. This characteristic could overcome limitations of other GKAs, such as hypoglycemia, increased plasma triglycerides, and loss of efficacy.