Synthesis and in vitro antibacterial activity of fluoroquinolone derivatives containing 3-(N'-alkoxycarbamimidoyl)-4-(alkoxyimino) pyrrolidines.

A series of novel 7-[3-(N'-alkoxycarbamimidoyl)-4-(alkoxyimino)pyrrolidin-1-yl] fluoroquinolone derivatives were designed, synthesized and characterized by (1)H NMR, MS and HRMS. These fluoroquinolones were screened for their in vitro antibacterial activity. Most of them exhibit good potency in inhibiting the growth of Staphylococcus aureus and Staphylococcus epidermidis (MIC: 0.06-4.00 μg/mL). The activity of compounds 33 and 43 against S. aureus including MRSA and S. epidermidis including MRSE (MIC: 0.06-0.125 μg/mL) is more than or comparable to the reference drugs levofloxacin and gemifloxacin. In addition, compound 33 is 32 and 16-32 fold more potent than both the reference drugs against Enterococcus faecium 08-7 and Klebsiella pneumoniae 09-22, respectively.