RESUMEN
Mousouchiku extract is prepared from the bamboo-sheath of Phyllostachys heterocycla MITF. (Poaceae), and is registered as a food manufacturing agent in the List of Existing Food Additives in Japan. This study describes the chromatographic evaluation of characteristic components of this extract to obtain the chemical data needed for standardized specifications. We isolated 12 known compounds from this extract: 5-hydroxymethyl-2-furfural, 4-hydroxybenzoic acid, trans-p-coumaric acid, trans-ferulic acid, N,N'-diferuloylputrescine, 4'-hydroxypropiophenone, ß-arbutin, tachioside, isotachioside, 3,4'-dihydroxypropiophenone 3-O-glucoside, koaburaside, and (+)-lyoniresinol 9'-O-glucoside. Moreover, a new propiophenone glycoside, propiophenone 4'-O-(6-ß-D-xylosyl)-ß-D-glucoside (propiophenone 4'-O-primeveroside), was isolated. The structure of each isolated compound was elucidated based on NMR and MS data or direct HPLC comparisons with authentic samples. Among the isolates, (+)-lyoniresinol 9'-O-glucoside was found to be the major ingredients of the extract as observed using HPLC analysis. However, 2,6-dimethoxy-1,4-benzoquinone, which is considered the main constituent of mousouchiku extract, was only detected as a trace constituent and not isolated in this study.
Asunto(s)
Aditivos Alimentarios/química , Fenoles/química , Poaceae/química , Antiinfecciosos/química , Antiinfecciosos/aislamiento & purificación , Antiinfecciosos/farmacología , Cromatografía Líquida de Alta Presión , Escherichia coli/efectos de los fármacos , Aditivos Alimentarios/aislamiento & purificación , Espectroscopía de Resonancia Magnética , Espectrometría de Masas , Pruebas de Sensibilidad Microbiana , Conformación Molecular , Fenoles/aislamiento & purificación , Fenoles/farmacología , Extractos Vegetales/química , Poaceae/metabolismo , Staphylococcus aureus/efectos de los fármacosRESUMEN
The associative interaction between resin-bound polybrominated arenes and small molecules was analyzed by using various spectroscopic techniques as well as a synthetic molecular model to establish the thermodynamics. The binding in acetonitrile was three orders of magnitude stronger than that in methanol, partly owing to the tertiary conformational gating of the resin that controls the entropic terms. By using the entropic superiority, the associative binding of up to 3×104 m-1 is achieved with the non-biological system. A modified Hill plot for the quantitative analysis of bindings was also devised, which enabled the interactions at the molecular level to be elucidated.