Distinguishing isomeric aldohexose-ketohexose disaccharides by electrospray ionization mass spectrometry in positive mode

Abstract

Glc-Fru isomers were discriminated in the PCA score plots for their lithium and sodium adducts by using different collision modes. The results showed that HCD-MS/MS is an ideal tool for differentiating lithium adducts, whereas, CID-MS/MS is better for discriminating sodium adducts. The hydrogen migration of the hydroxyl group at C3 of the fructose unit caused the glycosidic bond decomposition of lithiated sucrose.

MALDI‐MS Analysis of Sucrose Using a Charcoal Matrix with Different Cationization Agents

“…Figure shows the structures of sucrose and its potential sodium‐adducted fragment ions. Cleavage of the glycosidic bonds is widely known to be the main mechanism for generating fragment ions, where glucosyl‐oxygen bond cleavage provides B 1 and Y 1 ions and fructosyl‐oxygen bond cleavage generates C 1 and Z 1 ions. In general, the fragmentation of carbohydrates containing reducing ends results in abundant losses of reducing‐terminal residues, generating B‐type or Y‐type ions .…”

Neutral losses of sodium benzoate and benzoic acid in the fragmentation of the [M + Na]+ ions of methoxyfenozide and tebufenozide via intramolecular rearrangement in electrospray ionization tandem mass spectrometry

“…In some cases, the Na + only acts as a charge tag but is not involved in the fragmentation: so‐called charge‐remote fragmentation . In other cases, the Na + plays an important role in the fragmentation, which can affect the CID process . The effect of Na + is usually compared with another alkali metal cation, Li + , and they can lead to different fragmentation behavior because of the stronger inductive effect of Li + than that of Na + .…”

Distinguishing Linkage Position and Anomeric Configuration of Glucose–Glucose Disaccharides by Water Adduction to Lithiated Molecules

“…Collision-induced dissociation (CID) was reported to distinguish the linkage position for several disaccharides. , CID was then used to determine the anomericity of several disaccharides that were first derivatized with Zn­(II)-diethylenetriamine chloride prior to mass spectral analysis . Since then, other methods have been developed to determine linkage position and the anomericity of some linkages, which do not require a prior derivatization step. − Most of these methods report relatively high concentrations (typically ≥100 μM) to provide sufficient signal intensity to confidently distinguish isomers. High concentrations are necessary for determining the anomericity of the linkage because there are only very small differences in product ions ratios.…”