Di- and Oligo-saccharides

II. Synthesis of Septanose-Containing Mono-, Di-, and Oligo-Saccharides 127... 

However, two other applications of mass spectrometry to carbohydrate chemistry seem the most important and promising. These are the identification of partially methylated monosaccharides, and structural analysis of di- and oligo-saccharides (and penetration of this new technique into polysaccharide chemistry). 

This biochemical technique has been extended to the preparation of many di- and oligo-saccharides. The a-D-fructofuranosyl derivatives of 2-deoxy-D-fcraftt no-hexose (6-linked)1 1 and of D-xylose1 have been prepared. 

Applying periodic acid oxidation to reducing di- and oligo-saccharides having (1 — 4) linkages, J. E. Courtois observed the overoxidation phenomenon, which was further extended by study of the oxidation of malonic, malic, and citric acids. Two heteroside structures, amygdaloside and vician-oside, were also studied with this reagent. 

Obviously, these methods are inapplicable to esterification of free sugars and of alkali-labile glycosides and esters (including the resultant sulfonic esters), but may be employed with sugar alcohols, non-reducing di- and oligo-saccharides, and alkali-stable glycosides and acetals (e.g., certain-O-isopropylidene derivatives). 

Other Disaccharides. Amino sugar-containing di- and oligo-saccharides of undetermined structure have been demonstrated in certain enzymic, synthetic reactions.298... 

In the case of di- and oligo-saccharides, a simpler method may be employed. The aqueous extract of the pherogram is added to a short carbon-Celite column, inorganic material is eluted with water, and the carbohydrate is subsequently eluted with aqueous ethanol. This method may be used for any substance which is not readily eluted from a carbon-Celite column by water but which can be eluted with aqueous ethanol. Alternatively, the saccharide extracted from the pherogram may be acetylated. ... 

Tomasik, P., Palasinski, M., and Wiejak, S., The thermal decomposition of carbohydrates. Part I. The decomposition of mono-, di-, and oligo-saccharides, Adv. Carbohydr. Chem. Biochem., 47, 203, 1989. 

Despite the valuable preliminary biochemical investigations outlined, the chemical behavior of the erythro and threo isomers of 4-deoxy-L-hex-4-enopyranuronates has not yet been thoroughly studied. Similarly, more-detailed chemical studies in the field of the di- and oligo-saccharides having terminally linked, unsaturated deoxyhexopyranuronate residues have not been made. 

Di- and oligo-saccharide derivatives are less sensitive to dehydration reactions in the course of the Maillard reaction, and contribute less to color formation, as compared to the respective monosaccharides. ... 

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