RESUMO
The aim of this study was to evaluate the antimicrobial activity of lapachol, α-lapachone, ß-lapachone and six antimicrobials (ampicillin, amoxicillin/clavulanic acid, cefoxitin, gentamicin, ciprofloxacin and meropenem) against twelve strains of Staphylococcus aureus from which resistance phenotypes were previously determined by the disk diffusion method. Five S. aureus strains (LFBM 01, LFBM 26, LFBM 28, LFBM 31 and LFBM 33) showed resistance to all antimicrobial agents tested and were selected for the study of the interaction between ß-lapachone and antimicrobial agents, busing checkerboard method. The criteria used to evaluate the synergistic activity were defined by the Fractional Inhibitory Concentration Index (FICI). Among the naphthoquinones, ß-lapachone was the most effective against S. aureus strains. FICI values ranged from 0.07 to 0.5, suggesting a synergistic interaction against multidrug resistant S. aureus (MRSA) strains. An additive effect was observed with the combination ß-lapachone/ciprofloxacin against the LFBM 33 strain. The combination of ß-lapachone with cefoxitin showed no added benefit against LFBM 31 and LFBM 33 strains. This study demonstrated that, in general, ß-lapachone combined with beta lactams antimicrobials, fluoroquinolones and carbapenems acts synergistically inhibiting MRSA strains.
Assuntos
Antibacterianos/farmacologia , Ciprofloxacina/farmacologia , Resistência a Meticilina/efeitos dos fármacos , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Naftoquinonas/farmacologia , Infecções Estafilocócicas/microbiologia , Tabebuia/química , Combinação de Medicamentos , Sinergismo Farmacológico , Humanos , Testes de Sensibilidade MicrobianaRESUMO
O Plantago major é uma planta herbácea conhecida como transagem que ocorre espontaneamente nas regiões de clima temperado ou subtropical, sendo facilmente cultivada no Brasil. Popularmente é utilizada no tratamento de inflamações de boca e garganta, infecções intestinais e como agente antibacteriano. O infuso das folhas é usado como gargarejo no combate às inflamações da boca, garganta, gengivas sangrentas e parotidites. O estudo microbiológico para a avaliação da atividade do extrato hidro-alcoólico foi realizado pelo método de difusão em meio sólido, frente a doze isolados clínicos de Staphylococcus aureus, obtidos de feridas abertas da pele, secreções vaginais e da orofaringe. O extrato foi padronizado obtendo-se uma solução de concentração igual à 193,0 mg/ml. Os microrganismos foram identificados através de provas bioquímicas específicas e suas culturas foram mantidas em meio sólido Mueller-Hinton. A ciprofloxacina foi utilizada como padrão antibacteriano na concentração de 10,0 mg/ml. Os microrganismos mostraram-se sensíveis ao extrato hidro-alcoólico, apresentando halos de inibição entre 10,0 e 13,0 mm e para o padrão ciprofloxacina entre 10,0 e 15,0 mm. Baseados nos estudos acima descritos o trabalho continuará com a determinação da Concentração Mínima Inibitória (CMI).
RESUMO
The synthesis and physicochemical properties of 4-butyl-2H-benzo[1,4]thiazin-3-one derivatives are described. These new compounds were synthesised by alkylation in 4-N position and acylation and/or alkylation of 6-NH2 by phase transfer catalysis. Acid hydrolysis of 6-alkylacylamino group yielded 6-alkylamino-4-butyl-2H-benzo[1,4]thiazin-3-ones. The antimicrobial in vitro activity was determined on five compounds.
Assuntos
Anti-Infecciosos/síntese química , Tiazinas/síntese química , Anti-Infecciosos/química , Anti-Infecciosos/farmacologia , Testes de Sensibilidade Microbiana , Tiazinas/farmacologiaRESUMO
Synthesis and physico-chemical properties of 3-(4-bromobenzyl)-, 3-(4-chlorobenzyl)-5-arylidene-thiazolidine-2,4-diones and 3-(4-chlorobenzyl)-4-thioxo-5-arylidene-thiazolidin-2- ones are described. Twelve new products were synthesized by the aldolisation-crotonisation reaction from aromatic aldehydes and N-alkylated thiazolidinediones or thioxothiazolidinones. Seven compounds were preliminary tested for their bacteriostatic activity.
Assuntos
Antibacterianos/síntese química , Tiazóis/síntese química , Antibacterianos/farmacologia , Bactérias/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Tiazóis/farmacologiaRESUMO
Synthesis and physico-chemical properties of new 3-benzyl-4-thioxo-5-arylideneimidazolidine-2-ones and 3-benzyl-5-arylideneimidazolidine-2,4-dione are described. These compounds were synthesized by condensation reaction from aromatic aldehydes and 3-substituted imidazolidine-2,4-diones or 4-thioxoimidazolidine-2-ones. The N-alkylation of 5-benzylideneimidazolidine-2,4-dione led simultaneously to mono- and dialkylated derivatives. The nucleophilic addition of 1-methyl-3-benzylimidazolidine-2,4-dione with 2-cyano-3-(3,4-dichlorophenyl) acrylate also yielded the 3-substituted 5-arylideneimidazolidine-2,4-dione derivative. Antimicrobial in vitro activity was determined on some compounds.
Assuntos
Antibacterianos/síntese química , Imidazóis/síntese química , Antibacterianos/química , Antibacterianos/farmacologia , Bactérias/efeitos dos fármacos , Contagem de Colônia Microbiana , Cromatografia Gasosa-Espectrometria de Massas , Imidazóis/química , Imidazóis/farmacologiaRESUMO
Synthesis and physico-chemical properties of four 3-benzyl or 3-(4-chlorobenzyl)-4-thioxo-5-arylazo-imidazolidin-2-ones, five 3-(4-nitrobenzyl)-5-arylidenethiazolidine-2,4-diones and three 3-(4-phenyl-phenacyl)-4-thioxo-5-arylidenethiazolidin-2-ones have been described. These new products were synthesized by an aldolisation-crotonisation reaction from aromatic aldehydes and 3-substituted thioxothiazolidin-2-ones or thiazolidine-2,4-diones. The arylazo-imidazolidine compounds were synthesized by copulation of diazonium ions with imidazolidines. Antimicrobial activity was determined for some compounds.