Novel Alanine-based Antimicrobial and Antioxidant Agents: Synthesis and Molecular Docking

Abstract
Objective: To synthesize new alanine-based phenyl sulphonamide derivatives with significant antimicrobial and antioxidant activities.

Methods: The reaction of alanine with benzene sulphonyl chloride afforded compound 3a. The ammonolysis of its N-acylated derivative gave the carboxamide which yielded the aryl/heteroaryl derivatives compounds 3d, 3e, and 3f via Buchwald–Hartwig nickel catalyzed amidation reaction. Structures agreed with the spectra data. Their antimicrobial activities, antioxidant activities, and molecular docking interactions were evaluated.

Findings: Compounds 3f and 3a was the best antimicrobial agents with minimum inhibitory concentration (MIC) range of 0.5–1.0 µg/ml while compound 3a displayed the highest in vitro antioxidant percentage inhibition of 95.70% and the best 50% inhibitory concentration (IC50) value of 1.072 ± 0.002 µg/ml comparable to ascorbic acid of 96.38% antioxidant percentage inhibition and 0.999 ± 0.001 µg/ml IC50 value. Compounds 3c, 3a, and 3f had the highest in silico antibacterial, antifungal, and antioxidant binding energies of −10.03, −11.79, and −13.13 kcal/mol, respectively.

Novelty/improvement: Alanine was found to potentiate the antimicrobial and antioxidant actions of benzenesulphonamide and carboxamide derivatives.

Keywords: Alanine, Antimicrobial, Phenylsulphonamide, Molecular Docking, Antioxidant.