Bacterial resistance is the most dangerous and critical problem associated with the use of antibiotics, due to the uncontrolled and miss use of many types of them. Fluoroquinolones are a class of antibacterial agents that possess an anti-inflammatory effect in addition to their antibacterial effect, and they are resisted by many species of microorganisms through different mechanisms. It was found that increase bulkiness at C7 of fluoroquinolones moiety will reduce bacterial resistance by reducing the effect of the efflux pump, and it was also reported that this modification will improve anti-inflammatory activity. So, thiazole ring and a group of its derivatives (which possess antibacterial and anti-inflammatory activity) were incorporated into a secondary amine at the piperazine ring of norfloxacin. Using FT-IR spectroscopy, 1H-NMR spectral, and some physical-physiochemical properties, the synthesized compounds were confirmed and characterized for their chemical structures. In vivo, an acute anti-inflammatory effect of compounds, III and IVa-f, was estimated using the paw-edema model in rats. Norfloxacin 20mg/kg, and diclofenac sodium 3mg/kg were employed as reference drugs. All tested compounds exhibited significant (p<0.05) reduction in the paw edema when compared to the control group (propylene glycol (PG)). In in-vitro, the antibacterial effect of all synthesized compounds was evaluated via the use of the agar-well diffusion method (AWD). The antibacterial study was shown a topmost inhibition zone for the compound III against E. coli and the lowest inhibition zone for the compound IVd against Staphylococcus aureus. Docking studies showed the affinity of the synthesized compounds toward the topoisomerase enzyme.
