Design, synthesis and in vitro study of densely functionalized oxindoles as potent α-glucosidase inhibitors

Diabetes a non-communicable disease occurs either due to the lack of insulin or the inability of the human body to recognize it. The recent data indicated an increase in the trend of people diagnosed with type 2 diabetes mainly due to unhealthy life style. Here in we report a new class of oxindole derivatives 6a-kvia scaffold hopping of known α-glucosidase inhibitors 1-4. When molecular docking was performed against a homology model of α-glucosidase the resulting compound 6d revealed binding interactions comparable to 1-4. The compounds were accessed through a unique condensation-ring opening protocol of pyridofuranone building blocks. Overall the compounds exhibited decent binding to the yeast α-glucosidase, where the most potent compound 6h, inhibited the enzyme with IC₅₀ of 0.6 µM. This was nearly threefold improvement from the original known compounds 1-4, selected to design the newer analogs. The reaction kinetics of 6h indicated competitive inhibition.