Assuntos
Flavonoides , Glucosídeos/química , Quempferóis , Plantas Medicinais/química , Saponinas/química , Trissacarídeos/química , Configuração de Carboidratos , Sequência de Carboidratos , Espectroscopia de Ressonância Magnética/métodos , Dados de Sequência Molecular , Espectrofotometria Ultravioleta , EstereoisomerismoRESUMO
Crystal growth of monohydrogen potassium L-tartrate in an ethanolic aqueous solution was specifically inhibited by d-catechin, but not by either its epimeric isomer at C3, l-epicatechin or by gallic acid and caffeic acid. 3D-Structure similarity search of d-catechin with two molecules of the tartrate and docking study of d-catechin with the crystal model of the tartrate suggested that d-catechin mimics a structure consisting of the two tartrate molecules in the inhibition. Differences in the conformation of the catechol moieties of d-catechin and l-epicatechin may explain the distinct inhibitory effects of the epimeric isomers.
Assuntos
Catequina/química , Flavonoides , Tartaratos/química , Gráficos por Computador , Cristalização , Estrutura Molecular , Fenóis/química , Polímeros/química , SoftwareRESUMO
A new antibiotic compound, sarothralin G from Hypericum japonicum Thunb. (Sarothra japonica) has been isolated and its structure was elucidated on the basis of spectroscopic data. The compound contains phloroglucinol and filicinic acid moieties.
Assuntos
Anti-Infecciosos/isolamento & purificação , Medicamentos de Ervas Chinesas/análise , Floroglucinol/farmacologia , Espectroscopia de Ressonância Magnética , Estrutura Molecular , Floroglucinol/isolamento & purificaçãoRESUMO
ATP and AMP were immediately converted into ADP by intact cells of Escherichia coli in the presence of Mg2+, while ADP was also rapidly converted into ATP and AMP under the same conditions. Adenylate kinase was released when E. coli cells were converted to spheroplasts by treatment with lysozyme-EDTA or osmotic shock. Adenylate kinase activities detected in the cytoplasm, periplasm and membrane fractions were approximately 58%, 36% and 6% of the total cellular activity, respectively. These results indicate that adenylate kinase in E. coli occurs in the periplasm as well as the cytoplasm.
