Synthesis, Antibacterial Evaluation, and Docking Studies of Some Azo Compounds and Schiff Bases Derived from Sulfonamide

Objective: The aim of study was to synthesize new products of sulfonamide compounds containing azo and Schiff base fragments and confirm the structures by ۱H-NMR and FT-IR spectroscopy, as well as to investigate the antibacterial activities against medically important Gram (+) and Gram (-) bacterial strains.Materials and Methods: Novel sulfonamides derivatives S۱, S۲, S۳, A۱, A۲, and A۳ were synthesized and tested with staphylococcus aureus and Pseudomonas aeruginosa as well as against Candida albicans fungi. Molecular docking was used to study the theoretical binding of the compounds with some selected proteins.Results: It was found that compounds S۱, S۲, and S۳ have more potent activity against the three types of microorganisms as compared with A۱, A۲, and A۳. Against Candida albicans, it was found that compounds S۱ and S۳ gave the best activity, ۲۱ and ۲۰ mm, respectively. Antibacterial activity showed that compound A۲ gave the best activity (۳۴ mm at ۱۰۰۰ µg/mL) against Staphylococcus aureus. Other compounds S۱, S۲, S۳, A۱, and A۳ gave very good activities against the same bacteria, ۲۹, ۱۳, ۲۹, ۲۸, and ۲۸ mm, respectively, at the same concentration. Antibacterial activity against Pseudomonas aeruginosa showed that the compounds S۱ gave the best inhibition zone (۲۵ mm) at ۱۰۰۰ µg/mL, whereas compounds S۲ and S۳ showed good potent activity (۱۵ and ۲۰ mm, respectively). Molecular docking studies showed that free binding energy (S) of the compounds against S. aureus using protein ۱JIJ were -۷.۱۵ to -۸.۶۰ kcal/mol, whereas free binding energy (S) using ۵V۵Z fungi protein gave the values -۷.۱۰ to -۸.۲۲ kcal/mol.Conclusion: Schiff bases gave good activity against the selected microorganism species compared with azo compounds. There is clear correlation between the activity of the compounds and their molecular docking through the high negative values of free binding energy.

Keywords:

azo compounds , Schiff bases , antibacterial , Antifungal , Molecular docking , Organic synthesis