排序方式: 共有12条查询结果,搜索用时 46 毫秒
1.
2.
3.
Vafiadi C Topakas E Bakx EJ Schols HA Christakopoulos P 《Molecules (Basel, Switzerland)》2007,12(7):1367-1375
The chemoenzymatic synthesis of feruloylated arabino-oligosaccharides has been achieved, using a feruloyl esterase type C from Sporotrichum thermophile (StFaeC).The structure of the feruloylated products was confirmed by ESI-MS(n). 相似文献
4.
5.
Kabel MA Heijnis WH Bakx EJ Kuijpers R Voragen AG Schols HA 《Journal of chromatography. A》2006,1137(1):119-126
Various plant polysaccharide derived mono- and oligosaccharides were derivatized with the fluorescent 9-aminopyrene-1,4,6-trisulfonate (APTS) and subjected to capillary electrophoresis (CE) in combination with laser induced fluorescence (LIF) detection. CE-LIF was suitable for mol-based quantification of various APTS-monosaccharides. CE-LIF of APTS-oligosaccharides showed high resolutions, while analysis times were at maximum 15 min. The coupling of CE to electrospray-iontrap mass spectrometery (MS) with online UV detection showed to be a powerful technique in the identification of APTS-oligosaccharides. For the first time, various APTS-xylo-oligosaccharides, having either no, O-acetyl, arabinosyl or xylosyl substitutions at varying positions, were identified by using CE-LIF and CE-MS(n). 相似文献
6.
The resistance of microfilters in a flow of micellar solutions indicates that the surfactant which is adsorbed in the pores
forms a mobile admicelle. The flow in these admicelles can be stopped by Marangoni forces if there is a concentration gradient
of surfactant across the filter. On the basis of thermodynamic concepts and experimental data it is argued that the resistance
of the filters could be affected by shear-induced surfactant adsorption. To minimize the entropy production in the flow through
a narrow pore the micellar solution separates into parallel fluxes of liquid through the lumen of the pore and of mobile surfactant
in the flowing admicelle.
Received: 14 July 1999 Accepted: 24 November 1999 相似文献
7.
Rudy Simons Jean‐Paul Vincken Edwin J. Bakx Marian A. Verbruggen Harry Gruppen 《Rapid communications in mass spectrometry : RCM》2009,23(19):3083-3093
Due to their substitution with an isoprenoid group, prenylated flavonoids have an increased affinity for biological membranes and target proteins, enhancing their potential bioactivity. Although many prenylated flavonoids have been described, there are no methods that specifically screen for their presence in complex mixtures, prior to purification. We describe a method based on ultra‐high‐performance liquid chromatography (UHPLC) with electrospray ionisation mass spectrometry (ESI‐MS) that allows rapid screening for prenylated flavonoids in multi‐component plant extracts. Identification of the prenylated flavonoids is based on screening for neutral losses of 42 u and 56 u in the positive‐ion mode MS2 and MS3 spectra within the MS chromatograms. In addition, this method discriminates between a prenyl chain and a ring‐closed prenyl (pyran ring), based on the ratio of the relative abundances of the ions that lose 42 u and 56 u (42:56). The application of this screening method on a 70% aq. ethanol, ethanol and ethyl acetate extract of the roots of Glycyrrhiza glabra indicated the presence of 70 mono‐ and di‐prenylated flavonoids. In addition, of each prenylated flavonoid the type of prenylation, chain or pyran ring was determined. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
8.
9.
10.