Quinoline-imidazo[1,2-a]pyridine conjugates as potential antioxidant agents: Synthesis, experimental and theoretical approaches

N-heterocyclic compounds such as quinolines and imidazopyridines are very important structures in medicinal chemistry, especially for drug development. In this work, a series of novel quinoline-imidazo[1,2-a]pyridines hybrids (IMP1-10) were synthesized from 3-(quinolin-3-yl) oxirane-2,2-carbonitriles (1-10) via a nucleophilic ring-opening reaction and were characterized by conventional analytical techniques. The antioxidant capacity of the synthesized compounds was investigated using the DPPH, FRAP and ABTS methods, and it was found that IMP-7 exhibited the best DPPH and FRAP activity with an IC₅₀ values of 0,33 ± 0,05 µM and 2387,45 ± 23,25 μmol TE/g, respectively. In the course of the analysis of the ABTS assay results, IMP-10 was found to demonstrate the highest activity, with an IC₅₀ value of 0.67 ± 0.04 µM. The antioxidant mechanism properties of the most potent compounds IMP-7, IMP-8 and IMP-10 were calculated with the Gaussian package program using HF/6-31++G(d,p) basis set.