Design, Synthesis, Molecular Docking, and Kinetic Study of 3-Amino-2,4-Diarylbenzo[4,5]Imidazo[1,2-a]Pyrimidines as Novel, Potent Α-Glucosidase Inhibitor

In an attempt to find novel, potent α-glucosidase inhibitors, a library of poly-substituted 3-amino-2,4-diarylbenzo[4,5]imidazo[1,2- a ]pyrimidines 3a-ag have been synthesized through heating a mixture of 2-aminobenzimidazoles 1 and α -azidochalcone 2 under the mild conditions. This efficient, facile protocol has been resulted into the desirable compounds with a wide substrate scope in good to excellent yields. Afterwards, their α-glucosidase inhibitory activities were investigated. Showing IC 50 values ranging from 16.4 ± 0.36 µM to 297.0 ± 1.2 µM confirmed their excellent potency to inhibit α-glucosidase which may provide new drug candidates in the treatment of type II diabetes mellitus. Among various synthesized 3-amino-2,4-diarylbenzo[4,5]imidazo[1,2- a ]pyrimidines, compound 3k exhibited the highest potency against α -glucosidase (IC 50 = 16.4 ± 0.36 μM) which was 45.7 times more potent than acarbose as standard inhibitor (IC 50 = 750.0 ± 1.5 μM). Moreover, the role of amine moiety on the observed activity was studied through substituting with chlorine and hydrogen resulted into a considerable deterioration on the inhibitory activity. Kinetic study and molecular docking study have confirmed the in-vitro results.