Synthesis, Computational Studies, and Biological Evaluation of Sulphamethoxazole-based Schiff Bases as Antimicrobial Agents

Background: Sulphamethoxazole-based Schiff-base compounds display poten-tial antibacterial and antifungal activity. Sulphamethoxazole is considered to be a versatile pharmacophore that can be utilized for designing and developing numerous bioactive lead compounds. In this work, some new sulphamethoxazole-based Schiff base compounds were synthesized, which are expected to possess antimicrobial activity, making them potentially useful for treating microbial infections. Objective: Concerning issues of drug resistance in presently available drugs, this study aimed to synthesize new sulphamethoxazole-based Schiff bases and evaluate their antimi-crobial activity. Methods: New sulphamethoxazole-based Schiff bases were synthesized by condensing sul-phamethoxazole with various acetophenones in methanol in the presence of glacial acetic acid. The synthesized compounds were characterized using various techniques, such as TLC, melting point, IR, NMR, and mass analysis. The computational properties of the com-pounds were also assessed using online software programs, and the similarity of the target compounds was also calculated as compared to sulphamethoxazole and clotrimazole. The antimicrobial activity of the target compounds was tested against Bacillus subtilis (Gram-positive), Escherichia coli (Gram-negative), and Candida albicans. Results: The target compounds (3a-f) were successfully synthesized and characterized by spectroscopic and analytical methods. The results of computational properties, similarity, and antimicrobial activity against B. subtilis, E. coli, and C. albicans of new sulphamethox-azole-based Schiff bases showed significant antimicrobial potential. Conclusion: The synthesized new Schiff bases, particularly compound 3c, exhibited prom-ising antimicrobial activity and good physicochemical properties as compared to standard drugs, indicating their potential for further development as antimicrobial agents.