Synthesis and in vitro antibacterial activity of a series of novel gatifloxacin derivatives

Abstract A series of novel gatifloxacin (GTFX) derivatives were designed, synthesized and characterized by 1 H NMR, 13 C NMR, MS and HRMS. These derivatives were evaluated for in vitro antibacterial activity against representative Gram-positive and Gram-negative strains. Our results reveal that most of the target compounds show good potency in inhibiting the growth of Staphylococcus aureus including MRSA and Staphylococcus epidermidis including MRSE. Compounds 8 , 14 and 20 have useful activity against all of the tested Gram-positive and Gram-negative strains (MICs: 0.06–4 μg/mL). In particular, 20 possessing a broad antimicrobial spectrum (MICs: 0.06–1 μg/mL) was found to be 2–32-folds more potent than the reference drug levofloxacin and parent GTFX against Pseudomonas aeruginosa .