Design, Synthesis, and Biological Evaluation of Fluoroquinolones Linked to 4-Thiazolidinone Moieties as Potent Antimicrobial Agents: Docking Analysis

Abstract— A series of novel fluoroquinolone thiazolidinone derivatives were synthesized and evaluated for their biological activity. All the newly synthesized compounds were characterized by IR, ¹H NMR, ¹³C NMR, mass spectral techniques, and elemental analysis. Our results reveal that compounds 6a–6j have considerable activity against Gram–positive microorganisms with MICs range 0.65–64.2 μg/mL and Gram–negative strains belongs to MICs range 3.1–84.7 μg/mL respectively. From screening antibacterial results 6f, 6g, and 6d showed outstanding antibacterial activity against S. aureus with MICs 0.65, 2.2 and 4.7 µg/mL respectively whereas 6f, 6e, 6c have good potency in inhibiting the growth of P. aeruginosa including zone of inhibition 33, 32, 30 mm. The most active ligand 6d reveals highest hydrophobic binding modes with IleA:97 [2.189 Å], IleA:126 [2.199 Å], carbon hydrogen and halogen bondings with ProA:214, GluA:96, AsnA:91, Π–Π, and Π-alkyl interaction PheA:474 [2.903 Å] respectively. Compounds 6b, 6d, 6g possesses highest drug likeness model score 1.52, 1.25, 1.22, and considering their bioactivity potentials, perhaps highly substitute thiazolidinone functionalized fluoroquinolones could be the future antibiotics.