Hamid Beyzaei
Hadis Hosseini Moghadam
Ghodsieh Bagherzade
Reza Aryan
Mohammadreza Moghaddam-Manesh

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 ۲-chloro۳-quinolinecarboxaldehyde and aniline derivatives. Their inhibitory activities were evaluated against ۶ gram-positive and ۲ 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: ۲-Chloro-۳-quinolinecarboxaldehyde Schiff bases could inhibit the growth of bacteria with IZDs of ۷.۵-۱۹.۸ mm, MICs of ۲۵۶-۲۰۴۸ μg mL-۱, and MBCs of ۵۱۲ to ≥۲۰۴۸ μg mL-۱. Conclusion: Moderate antibacterial effects were observed with heterocyclic Schiff bases. Complexation and structural changes can improve their antimicrobial properties.