RESUMO
Lonchocarpol A, a flavanone, demonstrates in vitro inhibitory activity against methicillin-resistant Staphylococcus aureus and vancomycin-resistant Enterococcus faecium. This activity is antagonized by mouse plasma, which may account for its lack of in vivo activity. This compound demonstrates no differentiation with respect to the inhibition of RNA, DNA, cell wall, and protein synthesis.
Assuntos
Antibacterianos/farmacologia , Isoflavonas/farmacologia , Animais , Antibacterianos/isolamento & purificação , Bacillus megaterium/efeitos dos fármacos , Ensaios de Seleção de Medicamentos Antitumorais , Enterococcus faecium/efeitos dos fármacos , Isoflavonas/isolamento & purificação , Leucemia L1210/patologia , Camundongos , Testes de Sensibilidade Microbiana , Mariposas/química , Mycobacterium/efeitos dos fármacos , Staphylococcus aureus/efeitos dos fármacos , Células Tumorais CultivadasRESUMO
gamma-Pyrone-3-acetic acid (L-741,494) is a novel metabolite produced by a culture of the fungal genus Xylaria. This substance is a water-soluble, competitive, irreversible inhibitor of Interleukin-1 beta Converting Enzyme that is inactive against papain and trypsin. It has a mol wt of 154 and an empirical formula of C7H6O4. We propose the name xylaric acid for this compound.
Assuntos
Acetatos/farmacologia , Cisteína Endopeptidases/química , Metaloendopeptidases/química , Pironas/farmacologia , Xylariales/metabolismo , Acetatos/química , Acetatos/isolamento & purificação , Sequência de Aminoácidos , Caspase 1 , Cromatografia por Troca Iônica , Espectroscopia de Ressonância Magnética , Dados de Sequência Molecular , Pironas/química , Pironas/isolamento & purificaçãoRESUMO
The solubility of antibiotics used in animal feeds in organic solvents was determined. The solubility data could be used in identification of classes and in some cases individual members of the same class of antibiotics, and in differential step(s) in the analysis of these antibiotics. A universal solvent was developed to extract all antibiotics from animal feeds.
Assuntos
Ração Animal/análise , Antibacterianos/química , Solventes/química , Animais , Antibacterianos/análise , Antibacterianos/isolamento & purificação , Alimentos Fortificados , SolubilidadeRESUMO
A new method was developed for the determination of antibiotics in animal feeds. This qualitative and quantitative method can be applied to 17 antibiotics currently accepted for use in animal feeds. A solvent prewash step is used to differentiate groups of antibiotics and individuals of the same class of antibiotics and to remove interfering substances. Agarose gel electrophoresis at pH 6.0 and 8.0 is used to further differentiate the individual antibiotics and as an agar diffusion assay. Minimum detectable concentrations of antibiotics currently accepted for use in animal feeds were determined against selected microorganisms.
Assuntos
Ração Animal/análise , Antibacterianos/análise , Antibacterianos/isolamento & purificação , Antibacterianos/farmacologia , Bactérias/efeitos dos fármacos , Bioensaio , Meios de Cultura , Eletroforese em Gel de Poliacrilamida , Indicadores e Reagentes , Macrolídeos , Neomicina/análise , Neomicina/farmacologia , Oxitetraciclina/análise , Oxitetraciclina/farmacologia , Peptídeos/análise , Peptídeos/farmacologia , Solubilidade , Tetraciclinas/análise , Tetraciclinas/farmacologiaAssuntos
Antibacterianos/síntese química , Colecistocinina/antagonistas & inibidores , Colecistocinina/metabolismo , Virginiamicina/análogos & derivados , Virginiamicina/síntese química , Animais , Antibacterianos/química , Antibacterianos/farmacologia , Encéfalo/efeitos dos fármacos , Encéfalo/metabolismo , Cobaias , Humanos , Testes de Sensibilidade Microbiana , Pâncreas/efeitos dos fármacos , Pâncreas/metabolismo , Ratos , Receptores da Colecistocinina/efeitos dos fármacos , Receptores da Colecistocinina/metabolismoRESUMO
A novel electrophoresis system using agarose gel has been developed for the separation and as an aid in the classification of antibiotics. This system utilizes Nunc cell factory disposable tissue culture dishes, which serve as bioassay dish and cooling chamber for agarose gel, in a custom designed electrophoresis unit. Tris(hydroxymethyl) methylamine-succinate buffer at pH 6.0 and 8.0 are employed as the electrolyte for electrophoresis. Bioautography was used as the indicator of mobility. Any agar diffusion assay can be modified to use this system. A suggested name for this system is Nunc cell factory agarose gel electrophoresis (NUAGE). Selected antibiotics, representative of the aminoglycoside, beta-lactam, macrolide, moenocinol, peptide, polyene, polyether, quinone and tetracycline classes, were separated with this system.
Assuntos
Ração Animal/análise , Antibacterianos/isolamento & purificação , Eletroforese em Gel de Ágar/métodos , Eletroforese em Gel de Ágar/instrumentaçãoRESUMO
A new system for screening antibiotics in animal feeds involves washing antibiotic-containing animal feeds with a series of organic solvents to eliminate interferences and partially separate the antibiotics. Antibiotics are then determined by using paper electrophoresis and thin-layer bioautography. This approach enables the separation and qualitative identification of 17 antibiotics currently used in animal feeds and provides the ability to detect low-level cross-contamination.
