Free glycans

Malto-oligosaccharides are produced during fermentation via the enzyme-catalyzed breakdown of large polysaccharides and are typically chains of 3-10 glucose monomers. ESI-MS was used to determine the distribution of malto-oligosaccharides in beer.185 Calibration used known concentrations of standard malto-oligosaccharides. Peak areas obtained on injections of diluted beer samples were then compared to the calibration, from which concentrations of malto-oligosaccharides in the beer were determined. 

---

Amino-4-hydroxybenzoic acid First matrix to be developed specifically for carbohydrates (free glycans) found to be useful for the analysis of glycoprotein A-glycans31... 

Arabinose phenylosazone Arabinose phenylosazone has proven to provide better resolution and sensitivity than DHB for neutral free glycans,39 also useful for the analysis of sialylated and sulfated glycans40,41 particularly in negative ion mode... 

The mass of the intact glycan can be obtained by addition of the residue masses plus die figure for fiie relevant terminal groups (18.153 for free glycan, 46.069 for methyl derivative and 102.090 for acetyl derivative. For fiie mass of fiie molecular ion, also add the mass of the adduct, i.e. 1.0079 for hydrogen, 22.9898 for sodium and 38.0983 for potassium. 

For the acceptor 2, the other partner in the reaction in Scheme 1, all hydroxyl groups, except the targeted one(s) are usually protected. Benzyl is the traditional permanent protecting group, for it must survive until the final step where it is removed to provide the free glycan . 

If the reducing end ring structure is important in certain circumstances, free glycans can be derivatized to glycosyl... 

Kdn can be detected in free glycans, glycolipids, and glycoproteins in various cells and tissues from animals that express NeuSAc. The expression level is very low in mammals. 

---