Disaccharides and Oligosaccharides

Abbreviations for use in representing oligosaccharides are shown in Table 5.3. See Pure Appl. Chem., 54, 1517, 1982. 

A number of names for modified sugars, which occur frequently in natural glycosides, are in common use. 

Allomethylose 6-Deoxyallose Cymarose 2,6-Dideoxy-3-0-methyl-n7 o-hexose 

Note that if the absolute configuration of a sugar is not clear from the literature, CAS makes certain assumptions, e.g., rhamnose is assumed to be l-. 

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Several monophasic solvent systems are useful for the separation of carbohydrate mixtures, and in all those listed in Table 9.3 the smallest solute molecules have the fastest mobility. Thus pentoses have higher RF values than hexoses, followed by disaccharides and oligosaccharides. 

This process is completed in the duodenum where pancreatic a-amylase produces a mixture of monosaccharides, disaccharides, and oligosaccharides. 

The specific correlations of functional groups with the chemical shifts of carbon and associated protons are always important tools for structure elucidation of simple sugars as well as complex oligosaccharides. The conformational behavior [65,66] of a particular disaccharide and oligosaccharide in solution is determined not only by intramolecular interactions but also by potential interactions that exist between the oligosaccharide and its environment. In particular, the nature of the solvent or more generally the environment in which the compound finds itself, can profoundly affect its geometry. Two such important factors, namely the fully solvated state (i. e. the molecule free in solution) and the molecule solvated by a macromolecular receptor (i. e. the molecule bound to the active site of the protein) contribute to the preferred conformation. 

Although glycosides of unsubstituted sugars have no great importance as reference compounds in carbohydrate chemistry, they are valuable as standard substrates in enzyme chemistry. Moreover, when it comes to the synthesis of natural glycosides, disaccharides, and oligosaccharides, the simple alkyl and aryl glycosides serve as prototypes. 

Starch is cleaved by salivary amylase in the mouth and by pancreatic amylase in the intestine to disaccharides and oligosaccharides. 

Vidadala SR, Hotha S (2009) Methyl glycosides are identified as glycosyl donors for the synthesis of glycosides, disaccharides and oligosaccharides. Chem Commun 18 2505-2507... 

ESI In-Source CID of Oligosaccharides In-source CID can also provide information on linkage and anomeric configurations [13,46]. Derivatization improves HPLC separation and fragmentation [46]. This aspect was demonstrated by the ESI in-source CID of / -aminobenzoic acid ethyl ester-labeled disaccharides and oligosaccharides [46]. 

D. T. Li and G. R. Her, Strncmral analysis of chromophore-labeled disaccharides and oligosaccharides by electrospray ionization mass spectrometry and high-performance liquid chromatography/electrospray ionization mass spectrometry, J. Mass Spectrom. 33, 644-652 (1998). 

Biological Activity of Sugars Disaccharides and oligosaccharides Sucrose... 

Disaccharides and oligosaccharides are ubquitous in plants and fungi. Several of these, [e.g., sucrose (37)] are among the most important energy transfer compounds in plants. 

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