RESUMO
Using liposome systems, we found that gallates with short alkyl chains were located in the external medium and those with longer alkyl chains were located in the surface region of lipid bilayer. Combinations of these gallates remarkably reduced oxacillin MICs against methicillin-resistant Staphylococcus aureus to below the antibiotic breakpoint (< or = 2 microg/ml).
Assuntos
Antibacterianos/farmacologia , Ácido Gálico/análogos & derivados , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Oxacilina/farmacologia , Galato de Propila/farmacologia , Sinergismo Farmacológico , Quimioterapia Combinada , Ácido Gálico/farmacologia , Humanos , Lipossomos , Meticilina/farmacologia , Testes de Sensibilidade Microbiana , Resistência beta-Lactâmica/efeitos dos fármacosRESUMO
Chromone glucosides, takanechromones A-C (1, 2 and 5) and chromanone glucosides, named takanechromanones A and B (3 and 4), were isolated from the methanolic extracts of Hypericumsikokumontanum together with 27 known compounds. Their structures were established based on spectroscopic evidence. The isolated compounds and some chromone derivatives were assayed for antimicrobial activity against Helicobacter pylori and cytotoxicity against human cancer cell lines.
Assuntos
Cromonas/química , Cromonas/farmacologia , Glucosídeos/química , Glucosídeos/farmacologia , Helicobacter pylori/efeitos dos fármacos , Hypericum/química , Antibacterianos/química , Antibacterianos/farmacologia , Antineoplásicos Fitogênicos/química , Antineoplásicos Fitogênicos/farmacologia , Linhagem Celular Tumoral , HumanosRESUMO
After establishing a linear relationship between the amount of penicillin-binding protein (PBP) 2a and membrane proteins of methicillin-resistant Staphylococcus aureus (MRSA) COL by dot-blot analysis using an antibody against PBP 2a, we determined the PBP 2a quantities in membrane fractions prepared from 14 different MRSA cells. Methicillin-sensitive S. aureus ATCC 6538P was used as a quality control strain. The amounts of PBP 2a diverged among the strains, and no relationship to beta-lactam MIC values were observed in the corresponding strains.
Assuntos
Proteínas de Bactérias/metabolismo , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Staphylococcus aureus Resistente à Meticilina/metabolismo , Proteínas de Ligação às Penicilinas/metabolismo , beta-Lactamas/farmacologia , Proteínas de Bactérias/análise , Proteínas de Bactérias/genética , Humanos , Immunoblotting , Técnicas In Vitro , Resistência a Meticilina , Staphylococcus aureus Resistente à Meticilina/genética , Staphylococcus aureus Resistente à Meticilina/isolamento & purificação , Testes de Sensibilidade Microbiana , Proteínas de Ligação às Penicilinas/análise , Proteínas de Ligação às Penicilinas/genética , Especificidade da Espécie , Infecções Estafilocócicas/tratamento farmacológico , Infecções Estafilocócicas/microbiologia , beta-Lactamas/administração & dosagemRESUMO
From Cladonia rangiferina were isolated two novel abietane diterpenoids, hanagokenols A (1) and B (2). Also in this investigation, four known abitetane diterpenoids (3-6), four known labdane diterpenoids (7-10), one known isopimarane diterpenoid (11), and six known aromatic compounds were isolated. These structures were elucidated primarily through extensive NMR experiments. Hanagokenol A (1) was a unique abietane diterpene having an ether linkage between C-6 and C-18 of sugiol. Hanagokenol B (2) is also a unique secoabietane diterpene, having gamma-lactone which occurred by cleavage and subsequently oxidation between C-6/C-7 of 12-hydroxydehydroabietinol. Furthermore, all the isolated compounds (1-17) were tested for the antimicrobial activity against methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant Enterococci (VRE).
