Novel fluoroquinolones analogues bearing 4-(arylcarbamoyl)benzyl: design, synthesis, and antibacterial evaluation.

Bacterial resistance to fluoroquinolone has been increasing at an alarming rate worldwide. In an attempt to find more potent anti-bacterial agents, an efficient, straightforward protocol was performed to obtain a large substrate scope of novel ciprofloxacin and sarafloxacin analogues conjugated with 4-(arylcarbamoyl)benzyl 7a-ab. All prepared compounds were evaluated for their anti-bacterial activities against three gram-positive strains (Methicillin resistant staphylococcus aureus (MRSA), Staphylococcus aureus, and Enterococcus faecalis) as well as three gram-negative strains (Pseudomonas aeruginosa, Klebsiella pneumonia, and Escherichia coli) through three standard methods including broth microdilution, agar-disc diffusion, and agar-well diffusion assays. Most of the compounds exhibited great to excellent anti-bacterial potencies against MRSA and S. aureus. Among the targeted compounds, derivative 7n exhibited great antibacterial potency, which was noticeably more potent than parent ciprofloxacin. Subsequently, a molecular docking study was performed for this compound to find out its probable binding mode with the active site of S. aureus DNA gyrase (PDB ID: 2XCT).