Synthesis, bioactivity, and molecular docking of benzimidazole-2-carbamate derivatives as potent α-glucosidase inhibitors

Since time immemorial, diabetes has claimed countless lives throughout the world, and hundreds of millions of people across the globe endure this chronic metabolic disorder with perpetual health complications. Hence, specialists in medicinal and bioorganic chemistry are continually invigorated to design and synthesize α-glucosidase inhibitors that could potentially act as antidiabetic agents. To this end, in this work we have produced a series of variously substituted piperazin-1-yl benzimidazole-2-carbamates (7a–f) from multistep reactions in experimental yields ranging from moderate to relatively high. Subsequent to chemical identification with HRMS and spectroscopic elucidation using NMR and vibrational spectroscopic techniques, 15 derivatives were investigated for potential α-glucosidase inhibitory behavior. All, but 7a-1, exhibited higher inhibition (IC₅₀: 118–742 μM) than acarbose (IC₅₀: 759 μM), the standard α-glucosidase inhibitor. The most effective inhibitors in this series were 7d-1 and 7f-2 with IC₅₀ values of 118 and 155 μM, respectively. Kinetic studies demonstrated that 7d-1 is a competitive inhibitor of α-glucosidase. Molecular docking was employed to provide insight into the interactions of these bioactive organic molecules with the amino acid residues at the active site of the foregoing enzyme.