Synthesis and In Vitro Antibacterial Evaluation of Schiff Bases Derived FROM 2-Chloro-3-Quinolinecarboxaldehyde

Background: Design, identification, and synthesis of new antimicrobial agents along with preventive proceedings are essential to confront antibiotic-resistant pathogenic bacteria. Heterocyclic Schiff bases are biologically important compounds whose antimicrobial potentials have been proven to bacterial and fungal pathogens. Objectives: In this study, some quinoline Schiff bases were synthesized from condensation of 2-chloro3-quinolinecarboxaldehyde and aniline derivatives. Their inhibitory activities were evaluated against 6 gram-positive and 2 gram-negative bacterial pathogens. Methods: Disc diffusion, broth microdilution, and time-kill tests were applied according to the CLSI guidelines to determine IZD, MIC, and MBC values. Results: 2-Chloro-3-quinolinecarboxaldehyde Schiff bases could inhibit the growth of bacteria with IZDs of 7.5-19.8 mm, MICs of 256-2048 μg mL-1, and MBCs of 512 to ≥2048 μg mL-1. Conclusion: Moderate antibacterial effects were observed with heterocyclic Schiff bases. Complexation and structural changes can improve their antimicrobial properties.