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Interglycosidic Linkage (interglycosidic + linkage)

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Chemistry100%

Selected Abstracts

Mass spectrometric methods for the characterisation and differentiation of isomeric O -diglycosyl flavonoids

PHYTOCHEMICAL ANALYSIS, Issue 3 2001
Yu-Liang Ma
Abstract Tandem mass spectrometric methods have been evaluated for the characterisation of the type and the differentiation of the interglycosidic linkage of isomeric flavonoid O -diglycosides. Based on the occurrence of internal monosaccharide residue loss and the relative abundances of Y-type ions formed by fragmentation at glycosidic bonds, four pairs of isomeric flavonoid O -diglycosides can be unambiguously differentiated. The different techniques used, i.e. linked scanning at constant B/E without collisional activation and low-energy collision-induced dissociation using methane or helium as collision gas, have been shown to be useful for distinguishing the two most common (1, 2- and 1, 6-) interglycosidic linkages, e.g. flavonoid O -neohesperidosides and O -rutinosides. Copyright © 2001 John Wiley & Sons, Ltd. [source]

First report of non-coloured flavonoids in Echium plantagineum bee pollen: differentiation of isomers by liquid chromatography/ion trap mass spectrometry

RAPID COMMUNICATIONS IN MASS SPECTROMETRY, Issue 6 2010
Federico Ferreres
Apicultural products have been widely used in diet complements as well as in phytotherapy. Bee pollen from Echium plantagineum was analysed by high-performance liquid chromatography/photodiode-array detection coupled to ion trap mass spectrometry (HPLC-PAD-MSn) with an electrospray ionisation interface. The structures have been determined by the study of the ion mass fragmentation, which characterises the interglycosidic linkage in glycosylated flavonoids and differentiates positional isomers. Twelve non-coloured flavonoids were characterised, being kaempferol-3- O -neohesperidoside the major compound, besides others in trace amounts. These include quercetin, kaempferol and isorhamnetin glycosides, with several of them being isomers. Acetylated derivatives are also described. This is the first time that non-coloured flavonoids are reported from this pollen, with MS fragmentation proving to be most useful in the elucidation of isomeric structures. Copyright © 2010 John Wiley & Sons, Ltd. [source]

Mass spectrometric methods for the characterisation and differentiation of isomeric O -diglycosyl flavonoids

PHYTOCHEMICAL ANALYSIS, Issue 3 2001
Yu-Liang Ma
Abstract Tandem mass spectrometric methods have been evaluated for the characterisation of the type and the differentiation of the interglycosidic linkage of isomeric flavonoid O -diglycosides. Based on the occurrence of internal monosaccharide residue loss and the relative abundances of Y-type ions formed by fragmentation at glycosidic bonds, four pairs of isomeric flavonoid O -diglycosides can be unambiguously differentiated. The different techniques used, i.e. linked scanning at constant B/E without collisional activation and low-energy collision-induced dissociation using methane or helium as collision gas, have been shown to be useful for distinguishing the two most common (1, 2- and 1, 6-) interglycosidic linkages, e.g. flavonoid O -neohesperidosides and O -rutinosides. Copyright © 2001 John Wiley & Sons, Ltd. [source]

Electrospray ionization ion trap mass spectrometry for structural characterization of oligosaccharides derivatized with 2-aminobenzamide

RAPID COMMUNICATIONS IN MASS SPECTROMETRY, Issue 9 2005
Willy Morelle
The use of electrospray ionization (ESI) quadrupole ion trap mass spectrometry and reversed-phase high-performance liquid chromatography (HPLC) for the characterization of 2-aminobenzamide (2AB)-labeled oligosaccharides and N-linked protein oligosaccharide mixtures is described. The major signals were obtained under these conditions from the [M+Na]+ ions for all 2AB-derivatized oligosaccharides. Under collision-induced dissociation, sodiated molecular species generated in the ESI mode yield simple and predictable mass spectra. Tandem mass spectrometry (MS/MS) experiments with orders higher than two offer a number of ways to enhance MS/MS spectra and to derive information not present in MS and MS2 spectra. Information on composition, sequence, branching and, to some extent, interglycosidic linkages can be deduced from fragments resulting from the cleavage of glycosidic bonds and from weak cross-ring cleavage products. Reversed-phase HPLC and derivatization by reductive amination using 2-aminobenzamide were finally applied to characterize a glycan pool enzymatically released from glycoproteins. Copyright © 2005 John Wiley & Sons, Ltd. [source]