Synthesis and Characterization of a Novel Hybrid Azo-Imine Scaffold with Antibacterial and Drug-Likeness Properties

A novel azo-imine derivative, AIPyr, was synthesized via a two-step process involving the diazotization of 3-aminopyridine followed by azo coupling with salicylaldehyde to form an aldehyde-functionalized azo intermediate, which was subsequently condensed with 4-ethyl aniline through a Schiff base reaction. The structure of AIPyr was confirmed by 1H and 13C NMR spectroscopy and elemental analysis. Its antibacterial activity was evaluated using the broth microdilution method against Escherichia coli (E. coli) O157:H7 and Staphylococcus aureus ATCC 25923. The compound exhibited selective antibacterial activity against E. coli, with a MIC value of 325 µg/mL and an MBC of 1300 µg/mL, while no significant inhibition was observed against S. aureus. In silico docking studies revealed moderate binding affinity to E. coli β-ketoacyl-ACP synthase III (1HNJ) and stronger interactions with the human VEGFR2 kinase domain (2XIR), suggesting a potential for broader protein interaction. ADME predictions using SwissADME indicated good gastrointestinal absorption, moderate solubility, and acceptable druglikeness, with minor structural alerts offering opportunities for future optimization. These findings support AIPyr as a synthetically accessible and biologically promising scaffold.