Synthesis, antioxidant and anti-diabetic potential of novel benzimidazole substituted coumarin-3-carboxamides

Abstract

A series of benzimidazole tethered coumarin-3-carboxamide analogues were synthesised and screened for their antioxidant potential using DPPH and ABTS assay. And α-amylase inhibition potential also verified using DNSA method.The compound 10j with picoline substitution on the carboxamide linker emerged as most potent analogue for DPPH radical scavenging with IC50value 89.57 μM in comparison with the standard ascorbic acid (IC50 value 92.67 μM) and the compound 10f with 3,5-dimethoxy phenyl substituted carboxamide linker exhibited strongest scavenging activity (IC50 = 93.45 μM) against ABTS radical compared with the standard drug Trolox (IC50 = 96.24 μM). However, all the compounds in the series showed moderate α-amylase inhibition and the compound 10f again emerged as best antidiabetic analogue in the series with IC50 67.52 μM in comparison with metformin standard (IC50 = 54.13 μM). Molecular docking study with the receptor protein alpha-amylase (PDB ID 4 × 9y) using Autodock Vina tool rationalised the results obtained.