Synthesis and antibacterial activity of 7-(7-aminomethyl-5-azaspiro 2,4 hept-5-yl)-1-cyclopropyl-6-fluoro-8-methoxy-1,4-dihydro-4-oxo-3-quinolinecarboxylic acid and its analogues / 药学学报

ABSTRACT

<p><b>AIM</b>To find new antibacterial agents of quinolone with high activity and low toxicity.</p><p><b>METHODS</b>To design and synthesize 7-(7-aminomethyl-5-azaspiro [2,4] hept-5-yl)-1-cyclopropyl-6-fluoro-8-methoxy-1,4-dihydro-4-oxo-3-quinolinecarboxylic acid and its analogues, and to study their antibacterial activity in vitro and in vivo.</p><p><b>RESULTS</b>Twenty new compounds (2 - 11, 17 - 26) were obtained including five targeted compounds (22 - 26). The structures of the compounds were confirmed by 1HNMR, MS and HRMS. Compounds 22 - 26 showed broad spectrum of antibacterial activity against Gram-positive and Gram-negative organisms. Especially for compound 24, the relevant MIC values for 13 strains of Gram-positive organisms were < 0.001 - 0.03 mg(-1), including 4 strains of S. pneumoniae, 2 strains of S. pyogenes, 3 strains of S. aureus and 2 strains of Enterococci which exhibited more potent activity than contrast agents (clinafloxacin and gatifloxacin). The MIC values of 24 for 6 strains Gram-positive organisms were 0.01 - 1 mg x L(-1), which exhibited equal or lower activity than contrast agents. They were more effective than ciprofloxacin and gatifloxacin against intraperitoneal infections caused by S. pneumoniae and S. aureus in mice.</p><p><b>CONCLUSION</b>Compounds (23, 24 and 26) showed excellent antibacterial activity in vitro and in vivo and should be worth further investigation.</p>