3 interglycosidic linkage

Ferreres F, Llorach R and Gil-Izquierdo A. 2004. Characterization of the interglycosidic linkage in di-, tri-, tetra- and pentaglycosylated flavonoids and differentiation of positional isomers by liquid chromatogra-phy/electrospray ionization tandem mass spectrometry. J Mass Spectrom 39(3) 312—321. 

Franski, R. et al., Differentiation of interglycosidic linkages in permethylated flavonoids from linked-scan mass spectra (B/E), J. Agric. Food Chem., 50, 976, 2002. 

Although FAB-MS gives information on the sequence of monosaccharides in the oligosaccharide moiety, it is not possible to determine the location of the interglycosidic linkages by this method. NMR has been the method of choice for complete characterization of the oligosaccharide chain. 

One common structural feature is the presence of a xylose unit attached to C-3 of the aglycone and substituted at C-2 with a quinovose unit. As shown in Table 2, carbons involved in the interglycosidic linkages show chemical shifts at 5 ca. 82-88 ppm, shifted downfield from those expected for the corresponding methyl glycopyranosides. 

In the mass spectrum of 36, the major pathway was initiated, as expected, by cleavage of the interglycosidic linkage, to give the glycosyl carbonium ions 78 (m/z 283) of the nonreducing group of the mole-... 

Finally, disaccharides with sulfur in the ring of the nonreducing sugar and basic nitrogen as interglycosidic linkage were prepared as potent glucoamylase inhibitors [97]. 

In O Scheme 67 is shown the assembly of the thio analogue of a phytoelicitor active heptasac-charide. In contrast to the above example, here all the thio-interglycosidic linkages are formed through the reaction of anomeric thiols with non-anomeric electrophiles [196],... 

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