Characteristic fragmentation patterns of trimethylsilyl and trimethylsilyl-oxime derivatives of plant disaccharides as obtained by gas chromatography coupled to ion-trap mass spectrometry

The characteristic fragmentation pattern of six reducing and two non reducing type disaccharides – (neohesperidose, acuminose, sambubiose, rutinose, vicianose, primverose, and two arabinosyl-inositols) has been described. These saccharides have not been previously identified by on-line chromatographic techniques. Unambiguous specific characteristics of the TMS (oxime)s such as mass distribution, syn/anti oximes ratios and elution order proved to be associated with their reducing or non reducing character, with their aldosyl property and with the position of their O-glycosidic linkages. The practical utility of the mass fragmentation study of these rare disaccharides was demonstrated, at the first time, by the simultaneous, on-line identification and quantification of the acuminose, vicianose, primverose and arabinosyl-inositol contents of tea leaves, from green and black tea blends of Indian and Chinese origin.

► Rare plant disaccharides were identified and quantified by GC–MS.
► Retention order and mass fragmentation of eight glycosides were characterized.
► Acidic and enzymatic extracts were analyzed as TMS-oximes.
► Glycosides found in tea: arabinosyl-inositols, acuminose, vicianose, primverose.