• 제목/요약/키워드: New quinolones

검색결과 26건 처리시간 0.025초

Antibacterial properties of quinolones

  • Yoshida, Hiroaki
    • 한국응용약물학회:학술대회논문집
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    • 한국응용약물학회 1997년도 춘계학술대회
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    • pp.40-47
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    • 1997
  • New quinolones generally have a broad antibacterial spectrum against gram-positive, gram-negative, glucose-nonfermenting and anaerobic bacteria. Some of newly developed quinolones have potent activities against S. aureus including MRSA, S.pneumoniae including PRSP, B. fragilis, chlamydiae, mycoplasmas and mycobacteria as well, and show good activities against various strains resistant to antibacterial agents of other classes. Quinolones display postantibiotic effects in vitro and are bactericidal at concentrations similar to or twice that of the minimum inhibitory concentrations (MICs) for susceptible pathogens. In experimental murine infection models including systemic infections with various pathogens such as S. aureus, S. pyogenes, S. pneumoniae, E. coli and P. aeruginosa, quinolones have shown good oral efficacy as well as parenteral efficacy. Good oral absorption and good tissue penetration of quinolones account for good therapeutic effects in clinical settings. The target of quinolones are two structurally related type II topoisomerases, DNA gyrase and DNA topoisomerase IV. Quinolones are shown to stabilize the ternary quinolone-gyrase-DNA complex and inhibit the religation of the cleaved double-stranded DNA. Bacteria can acquire resistance to quinolones by mutations of these target enzymes. Mutation sites and amino acid changes in DNA gyrase and DNA topoisomerase IV are similar in the organisms examined, suggesting that the mechanism of quinolone resistance in the target enzymes is essentially the same among various organisms. Quinolones act on both the target enzymes to different degrees depending on the organisms or agents tested, and bacteria become highly resistant to quinolones in a step-wise fashion. Incomplete cross-resistance among quinolones in some strains of E. coli and S. aureus suggests the possibility of finding quinolones active against quinolone-resistant strains which are prevailing now. To find such quinolones, the potency toward two target enzymes and the membrane permeability including influx and/or efflux systems should be taken into account.

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혼성 Bivalent Ligand 퀴놀론 유도체의 합성 (Synthesis of Hybrid Bivalent Ligand Quinolone Derivatives)

  • 이상필;임채욱;김동순;임철부
    • 약학회지
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    • 제38권6호
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    • pp.664-672
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    • 1994
  • Eighteen new hybrid bivalent ligand quinolones that contain two different type of pharmacophores in a single molecule were prepared and evaluated for in viかo antibacterial activity. Hybrid bivalent ligands p-nitrobenzyloxycarbonyl quinolones were prepared by the treatment of active esters of succinyl fluoroquinolones with 1,7-disubstituted fluoroquinolone carboxylic acids in DMF. Eighteen final quinolone carboxylic acids were obtained by the reduction of compounds $25{\sim}42$ with hydrogen in the presence of 10% Pd-C. Among these derivatives, compound[56] showed the most potent antibacterial activity against a wide range of microoranisms.

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세균성결막염에 대한 안과용 플루오로퀴놀론계 항균제의 효과: 체계적문헌고찰 (Effect of Ophthalmic Fluoroquinolones on Bacterial Conjunctivitis: Systematic Review)

  • 손현순
    • 약학회지
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    • 제55권1호
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    • pp.22-31
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    • 2011
  • This systematic review was conducted to assess the clinical effect of ocular fluoroquinolones used for the treatment of bacterial conjunctivitis. A literature search for randomized controlled clinical trials registered up to January 2010 based on PubMed database, using the following search terms: conjunctivitis and fluoroquinolones (besifloxacin, moxifloxacin, gatifloxacin, levofloxacin, lomefloxacin, ciprofloxacin and ofloxacin) were performed. Pooled data on the clinical resolution and bacterial eradication rates derived from selected 16 studies were reported as the relative risk (RR) and 95% confidence interval (95% CI) compared with placebo. Early clinical resolution and microbiological eradication rates in placebo were 28% and 62% respectively. Fluoroquinolones were significantly effective comparing to placebo: early RR 1.94 (95% CI 1.60~2.34) and late RR 1.30 (1.19~1.43) in clinical resolution rates, and early RR 1.75 (1.58~1.94) and late RR 1.28 (1.18~1.39) in microbiological eradication rates. Besifloxacin, ciprofloaxain and moxifloxacin in clinical resolution, and besifloxacin and levofloxacin in microbiological eradication showed higher RRs than pooled overall fluoroquinolones' RRs. New quinolones had higher antibacterial potencies for all pathogens isolated from bacterial conjunctivitis and resistant isolates than old generation quinolones. In conclusion, ocular 7 fluoroquinolones were all effective than placebo for bacterial conjunctivitis and there were differences between quinolones in early and late clinical resolutions and microbiological eradications, and no differences in safety comparing to placebo.

p-TSA를 이용한 퀴놀론 유도체의 비대칭 이합체 합성 (Synthesis of Asymmetric Dimer of Quinolone Derivatives Using p-TSA)

  • 박명숙
    • 약학회지
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    • 제48권3호
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    • pp.202-206
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    • 2004
  • New asymmetric dimers, N,N'-dialkyl-4'-hydroxy-4-oxo-2,2',3,3'-tetrahydro-2,2'-diphenyl-4,4'-quinolones 3a-f were synthesized through the dehydration and dea1coholation of N-alkylanilines and ethyl benzoylacetate. Dimers 3a-f were identified by NMR, IR and GC-MS. A series of dimer 3a-f has been synthesized using acid-catalyzed one-pot reaction that involved the condensation, cyc1ization and dimerization. Similarly, the 6,6'-methoxy (or 7,7'-methoxy) substituted dimers were prepared from N-alkyl-meta-(or para)-anisidines. Formation of dimers was undertaken with p-toluenesulfonic acid (p-TSA) at 90∼11$0^{\circ}C$ in toluene for 2∼6 hours over the Dean-Stark apparatus.

양만장에서 분리된 Edwardseilla tarda균에 대한 new quinolone계 약물의 항균작용 (Antibacterial activity of new quinolones against Edwardsiella tarda isolated from eel tanks)

  • 최민순;김경호;서영호;최상훈;박관하
    • 한국어병학회지
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    • 제9권2호
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    • pp.185-193
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    • 1996
  • 지금까지 사용해온 많은 항균제들에 대한 내성의 획득은 어병세균의 박멸을 어렵게 만드는 심각한 문제를 야기하고 있다. 이 연구에서는 최근 인간의 세균성 질병치료 목적으로 사용하기 시작하거나 개발중인 new quinolone계 약물 14종을 대상으로 군산근교와 뱀장어(Anguilla japonica) 양만장 사육수에서 분리한 75종의 Edwardsiella tarda균에 대한 항균활성을 측정함으로써 장래의 신규 수산용 항균제 개발에 필요한 정보를 얻고자 시도하였다. Broth dilution assay에 의해 측정한 in vitro 항균활성시험에서 DU-6859는 $MIC_{50}$$0.05{\mu}g$/ml로 가장 강력한 약효를 보여주었다. $MIC_{50}$값 0.2-$0.78{\mu}g$/ml의 범위에 드는 약물들인 T-3762, Bay-y3118, ciprofloxacin, norfloxacin, ofloxacin 및 tosufloxacin은 그 다음으로 강력한 약물군을 형성하였다. 한편 difloxacin, sparfloxacin, fleroxacin, Q-35, amifloxain, lomefloxacin 및 enoxain 등은 약효가 약한 약물들로서 $MIC_{50}$값이 1.56-$3.13{\mu}g$/ml 범위에 속하였다. 이들 항균제에 대해서 내성(MIC 값이 $v$/ml 이상으로 정하였을 때)을 가지고 있는 균수는 T-3762 및 Bay-y3118은 3주, norfloxacin은 5주, tosufloxacin 12주, ciprofloxacin 및 ofloxacin 13주, sparfloxacin 16주, fleroxacin 19주, amifloxacin 및 lomefloxacin 31주, Q-35 36주, enoxacin 41주, difloxacin 44주로 각각 나타났다. DU-6859의 경우에는 내성이 있는 균주가 전혀 발견되지 않았다. 이 연구 결과들은 new quinolone계 약물들 사이에도 Edwardsiella tarda균에 대한 항균활성이 다양함을 시사하며 또한 향후 항균제 도입에 중요한 참고자료로 이용될 수 있을 것이다.

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C7위치에 3-아미노-4-메칠치오메칠피로리디닐기를 치환한 신규 퀴놀론계 항생물질 DWP20349 및 DWP20351의 흰쥐에서의 체내동태 및 조직분포 (Pharmacokinetics and Tissue Distribution of DWP20349 and DWP20351, New Quinolones Having 3-Amino-4-methyl thiomethylpyrrolidinyl Group on C7, in Rats)

  • 조재열;남권호;유은숙;이재욱;유영효;박명환
    • 약학회지
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    • 제41권3호
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    • pp.312-320
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    • 1997
  • Pharmacokinetics and tissue distribution of DWP20349 and 20351, new quinolones, were examined in rats after a single intravenous and oral administration. Analyses of DWP20349 an d DWP20351 in plasma, tissue, and urine were determined by both HPLC and bioassay(microbiological assay). The plasma concentrations of the drugs declined biexponentially. The terminal half-lives ($t_{1/2\beta}$) of drugs were about 114 min (DWP20349) and 105 min (DWP20351) after intravenous dosing, and were 77 min (DWP20349) and 79 min (DWP20351) after oral dosing. The volume of distrbution at steady-state ($Vd_{ss}$) and total body clearances ($Cl_t$) of DWP20349 and DWP20351 were 760 ml/kg and 1126 ml/kg, and 5ml/min/kg and 10 ml/min/kg, respectively. The extents of bioavailability if DWP20349 and DWP20351 after oral administration were 29% and 28%, respectively. 24 h urinary recoveries measured by bioassay were 1.8% (DWP20349) and 1.3% (DWP20351) after oral dosing, and 2.4% (DWP20349) and 1.9% (DWP20351) after intravenous dosing. Plasma protein binding ratios ranged from 87%-90% (DWP20349) and 61%-68% (DWP20351). These drugs were highly distrbuted by the order of lung, kidney, liver and plasma (DWP20394), and lung, liver, kidney and plasma (DWP20351) after 1 hour orally administered.

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