RESUMO
A series of N-[5-(chlorobenzylthio)-1,3,4-thiadiazol-2-yl] piperazinyl quinolone derivatives (4a-I) have been synthesized by reaction of piperazinyl quinolones with 5-chloro-2-(chlorobenzylthio)-1,3,4-thiadiazoles. Their structures were confirmed by elemental analysis, IR and NMR spectra. The antibacterial activities of 4a-I against a variety of Gram-positive and Gram-negative bacteria were determined. Several compounds showed a good antibacterial activity against Gram-positive bacteria among which, compound 4e with a 2-chlorobenzylthio moiety in ciprofloxacin derivative, exhibited high activities against Staphylococcus aureus and Staphylococcus epidermidis (MIC = 0.06 microg/mL). The structure-activity relationship (SAR) study revealed that the position of chlorine atom on benzyl moiety would dramatically affect the antibacterial activities of the synthesized compounds.
Assuntos
Antibacterianos , Piperazinas , Quinolonas , Tiadiazóis , Antibacterianos/síntese química , Antibacterianos/química , Antibacterianos/farmacologia , Bactérias Gram-Negativas/efeitos dos fármacos , Bactérias Gram-Positivas/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Estrutura Molecular , Piperazinas/síntese química , Piperazinas/química , Piperazinas/farmacologia , Quinolonas/síntese química , Quinolonas/química , Quinolonas/farmacologia , Relação Estrutura-Atividade , Tiadiazóis/síntese química , Tiadiazóis/química , Tiadiazóis/farmacologiaRESUMO
A number of levofloxacin analogues carrying a 2-aryl-2-oxoethyl or a 2-aryl-2-oxyiminoethyl moiety attached to the piperazine ring at C-10 position have been prepared and evaluated as antibacterial agents against a series of Gram-positive and Gram-negative bacteria. Some of them exhibited significant inhibitory activity against Gram-positive bacteria.
Assuntos
Antibacterianos/síntese química , Antibacterianos/farmacologia , Levofloxacino , Ofloxacino/análogos & derivados , Ofloxacino/farmacologia , Antibacterianos/química , Estrutura Molecular , Ofloxacino/química , Relação Estrutura-AtividadeRESUMO
Novel levofloxacin-containing hybrids carrying a 5-(nitroaryl)-1,3,4-thiadiazol-2-yl group were synthesized and evaluated in vitro against Gram-positive and Gram-negative bacteria. Preliminary data indicated that levofloxacin-nitrofuran and levofloxacin-nitroimidazole hybrids have a potent activity against Gram-positive organisms with enhanced anti-staphylococcal activity compared with the parent quinolone (N-desmethyl levofloxacin).
