Synthesis and Antibacterial/Antitubercular/Antioxidant Activities of Compounds Containing Fluoroquinolone Ring Linked to a 4-thiazolidinone Moiety

Background: Tuberculosis (TB), a contagious airborne disease caused by pathogen Mycobacterium tuberculosis (M. tb) is the second leading cause of death world-wide among the transferable diseases. It is therefore necessary to devote continuing effort for the identification and development of New Chemical Entities (NCEs) as potential antimicrobial agents to address this serious health problem. Methods: A series of new compounds containing fluoroquinolone ring linked to a 4-thiazolidinone moiety were synthesized and evaluated for their potential pharmacological properties. The ZnCl2 mediated construction of 4-thiazolidinone ring via the condensation/cyclization of Schiff bases with thioglycolic acid was used as a key step for the multi-step synthesis of this class of compounds. Results: When tested for antibacterial, antifungal, antitubercular activities in vitro and antioxidant activities several of these compounds showed good activities. Two compounds showed activities against both gram-(+) and gram-(-) strains and Mycobacterium smegmatis H37Rv ATCC 27294 (MTB) with MIC 16.28 and 27.86 μM, respectively. They also showed free radical scavenging properties with IC50 values in the range 23-33 μM and are appeared to be promising. Conclusion: Our study revealed that the molecular framework presented here could be a useful template for the identification of novel small molecules as promising antimicrobial / amtitubercular agents.