Design, synthesis, and pharmacological evaluation of N-(4-mono and 4,5-disubstituted thiazol-2-yl)-2-aryl-3-(tetrahydro-2H-pyran-4-yl)propanamides as glucokinase activators

A series of N-thiazole substituted arylacetamides were designed on the basis of metabolic mechanism of the aminothiazole fragment as glucokinase (GK) activators for the treatment of type 2 diabetes. Instead of introducing a substituent to block the metabolic sensitive C-5 position on the thiazole core directly, a wide variety of C-4 or both C-4 and C-5 substitutions were explored. Compound R-9k bearing an iso-propyl group as the C-4 substituent was found possessing the highest GK activation potency with an EC₅₀ of 0.026 μM. This compound significantly increased both glucose uptake and glycogen synthesis in rat primary cultured hepatocytes. Moreover, single oral administration of compound R-9k exerted significant reduction of blood glucose levels in both ICR and ob/ob mice. These promising results indicated that compound R-9k is a potent orally active GK activator, and is warranted for further investigation as a new anti-diabetic treatment.