Synthesis of Sulphonamides Using Threonine, and Evaluation of Their Biological Activities

Aim: Series of bioactive sulphonamides were synthesized using threonine an essential amino acid and their antioxidant and antimicrobial activities were evaluated.

Methodology: The reaction of L-threonine with sulphonyl chloride afforded sulfamoyl carboxylic acids while their carboxamide derivatives were obtained via ammonolysis. The structures of the synthesized compounds were elucidated using FTIR, 1H-NMR, 13C-NMR and elemental analysis. The antioxidant and antimicrobial activities were determined In vitro and in silico.

Results: it was observed that the best in vitro antibacterial activities against Bacillus subtilis, Escherichia coli, Staphylococcus aureus, Salmonella typhi, Pseudomonas aeruginosa, and antifungal activities against Aspergillus niger and Candida albicans were exhibited by compounds 1b and 1d. Compound 1f (IC50 = 1.150±0.003µg/ml) displayed the best antioxidant activity. Compound 1a showed a higher antibacterial binding energy (-11.51 kcal/mol) than penicillin (-10.89 kcal/mol) while 1c had an antifungal binding energy (-10.48kcal/mol) comparable to ketoconazole (-10.85 kcal/mol).

Conclusion: The sulfonamide derivatives synthesized from threonine were found to be potential antimicrobial and antioxidant agents.