In-vitro microbiological evaluation of gemifloxacin derivatives: Synthesis, vibrational spectroscopy, molecular docking and DFT studies

Herein, to address the challenges associated with microbial resistance against antibiotics, three new gemifloxacin derivatives (G-D08, G-D09 and G-D10), have been synthesized using conventional esterification (Fischer) and amide approach (C-3 and C-7 modified) in efficient yields. UV-Vis, FT-IR, 1HNMR, and Mass spectroscopy for characterization while DFT studies for computational conformational stability. In-silico pharmacokinetics (Swiss ADME, Bio transformers) and toxicological properties (T.E.S.T software) evaluated that all derivatives followed Lipinski's criterion and exhibits no vital organ toxicity. Microbiological evaluation in reciprocation towards designated strains of Gram +ve and Gram -ve bacteria, and fungi demonstrated potent actuation towards K. pneumonia, Candida albicans and Citrobacter freundii in comparison to gemifloxacin, surpassing antibacterial and antifungal responsiveness, reinforced by B3LYP/6–311 G level of theory. Energy gaps (HOMO-LUMO) of derivative G-D09 and G-D10 is 1.72 eV determinant as cognizant. Molecular docking approach was also applied through MOE software against K. pneumonia (PDB ID: 6k63), C. freundii (PDB ID: 3JWB) and C. albicans (PDB ID: 1AI9) ranging between -6.05 and -7.79 kcal/ mol, authenticating their higher antibacterial response towards Klebsiella pneumoniae among all compounds and G-D10 as potent antifungal agent.