Synthesis and Characterization of C-3 Modified Gemifloxacin Derivatives as Potential Anti-Urease and Antimicrobial Agents

Background: Quinolones derivatives have been clinically effective and are used to treat bacterial infections in either community or hospital environments. In current circumstances, acquired microbial resistance (AMR) have gained profound interest for investigators due to irregular/ misuse of antibiotics. Objective: In order to overwhelm the resistance and increase the effectiveness, gemifloxacin-H2 receptor antagonist (cimetidine, famotidine and ranitidine) carboxamide derivatives were designed and synthesized by means of structural modifications at the C-3 position of gemifloxacin (GMFX), an important member of fluoroquinolone class. Method: Synthesis method allows incorporating number of substituents (cimetidine, famotidine and ranitidine)on carboxylic group of gemifloxacinpresent at position C-3. These synthesized derivatives were screened for their physicochemical properties and structurally characterized by spectroscopic analysis (UV-Vis, FT-IR, 1HNMR and Mass). Their in-vitro microbial activities (disk diffusion method) and anti-urease effectiveness were also determined. Results: Three new carboxamide derivatives (G-D21, G-D22 and G-D23) were synthesized in good yield. Spectroscopic studies reveals that the changes occurs at 1645-1639cm-1 attributed to υ(C=O) carb, which was originally observed at 1641-1633 cm-1 in gemifloxacin, indicating formation of amide bond. These derivatives didnot exhibit strong antibacterial response but G-D22 possess highest anti-urease activity (93.5%). Conclusion: Therefore, here we can conclude that these characterized carboxamide derivatives of gemifloxacin didn’t exhibits microbial activities better than gemifloxacin against the studied organisms rather they were potent against the urease enzyme than the parent molecule.