ABSTRACT
To explore new agents of quinolone derivatives with high antibacterial activity, 7-(4-alkoxyimino-3-methyl-3-methylaminopiperidin-1-yl)quinolones were designed and synthesized, and their activity against gram-positive and gram-negative strains was tested in vitro. Sixteen target compounds were obtained. Their structures were established by 1H NMR, HRMS and X-ray crystallographic analysis. Compounds 14k and 14m-14o show good antibacterial activity against the tested five gram-positive strains and five gram-negative strains (MIC: 0.25-16 micromg x mL(-1)), of which the most active compound 14o is 8-fold more potent than levofloxacin against S. pneumoniae (MIC: 4 microg x mL(-1)), and comparable to levofloxacin against S. aureus, S. epidermidis, E. faecalis and E. coli (MIC: 0.25-1 microg x mL(-1)), but generally less potent than gemifloxacin.
Subject(s)
Anti-Bacterial Agents , Chemistry , Pharmacology , Gram-Negative Bacteria , Gram-Positive Bacteria , Molecular Structure , Quinolones , Chemistry , PharmacologyABSTRACT
To explore new agents of quinolone derivatives with high activity against Gram-positive and Gram-negative microorganisms, 7-(3-amino-4-alkoxyimino-1-piperidyl) quinolones were designed and synthesized, and their activity against Gram-positive and Gram- negative microorganisms were tested in vivo and in vitro. Twenty one target compounds were obtained. Their structures were established by 1H NMR, HRMS and X-ray crystallographic analysis. The target compounds possess different antimicrobial activities against both Gram-negative and Gram-positive microorganisms. Compounds 14a and 14m have broad spectral antibacterial activities. They show better antibacterial activities against 12 strains Gram-positive bacteria than three references. In particular, their activities against S. aureus and S. epidermidis (including MRSA and MRSE) were 4 - 16 times than that of gemifloxacin and balofloxacin, and 8 - 64 times than that of levofloxacin. The MIC values to S. aureus strains of compounds 14a and 14m were 0.25 - 1 mg x L(-1) and 0.125 - 1 mg x L(-1), to S. epidermidis strains were 0.5 - 4 mg x L(-1) and 1 - 8 mg x L(-1) respectively. The in vivo results showed that they have as good internal protection as gemifloxacin and moxifloxacin against systemic infection model in mice (P > 0.05).
Subject(s)
Animals , Female , Male , Mice , Anti-Bacterial Agents , Pharmacology , Therapeutic Uses , Gram-Negative Bacteria , Gram-Positive Bacteria , Methicillin-Resistant Staphylococcus aureus , Microbial Sensitivity Tests , Molecular Structure , Pneumococcal Infections , Drug Therapy , Quinolones , Pharmacology , Therapeutic Uses , Random Allocation , Staphylococcal Infections , Drug TherapyABSTRACT
<p><b>AIM</b>To explore new agents of quinolone derivatives with high activity against Gram-positive organisms.</p><p><b>METHODS</b>dl-7-(4,4-Dimethyl-3- aminomethylpyrrolidinyl)-quinolones were designed and synthesized, and their activity against Gram-positive organisms was tested in vitro.</p><p><b>RESULTS</b>Ten target compounds were obtained. The structures of these compounds were confirmed by 1H NMR, MS. The target compounds with dl-4,4-dimethyl-3-( methyl) aminomethylpyrrolidine side chains had high activity against Gram-positive organisms. Especially the MIC values of compound 22 for 4 strains of Gram-positive resistant bacteria (two strains of MRSA and two of MRSE) were 0.015 -0.5 mg x L(-), which exhibited more potent activities than gatifloxacin (4 - 128 times). Its MIC value for Pseudomonas aeruginosa 03-5 (0.008 mg x L(-1)) was 4 times as that of gatifloxacin (0.03 mg x L(-1)).</p><p><b>CONCLUSION</b>The compound 22 showed high activity against Gram-positive organisms in vitro and it is worth of more investigation.</p>
Subject(s)
Anti-Bacterial Agents , Pharmacology , Gram-Negative Aerobic Bacteria , Gram-Positive Bacteria , Microbial Sensitivity Tests , Molecular Structure , Pseudomonas aeruginosa , Quinolones , Pharmacology , Staphylococcus epidermidisABSTRACT
<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>