Monosaccharides, derivatization

More suitable for the determination of medium-and high-molecular-weight polysaccharides Shorter (50%) analysis times Higher recoveries with greater accuracy Directly applicable to sugar samples Far more sensitive Allows separation of a and / anomers Preferable for monosaccharides Derivatization required... 

Chiesa, C., Oefner, P. J., Zieske, L. R. and O Neill, R. A. Micellar electrokinetic chromatography of monosaccharides derivatized with l-phenyl-3-methyl-2-pyrazolin-5-one. J Capillary Electrvphor, 2,175, 1995. 

Considers only the basic monosaccharide units. A derivatized monosaccharide unit, such as a D-galactopyranosyl 6-sulfate unit, is not considered as a unit separate from a D-galactopyranosyl unit, for example. 

Monosaccharides of glycopro- DaisoGel silica, in-column teins(as l-phenyl-3-methyl- derivatized by 5-pyrazolone derivatives) octadecyltrimethoxysilane or... 

The use of mass spectrometry to characterize oligosaccharides is not new. Indeed, GC/MS has been used for several decades to identify monosaccharides or very small oligosaccharides. The use of GC/MS needs the prior derivatization of these molecules by methylation, acetylation or trimethylsilylation. 

Today (2000), GC/MS is still the method of choice for the determination of the monosaccharide composition of oligosaccharides and is widely used. The analysis starts with the hydrolysis or alcoholysis of the oligosaccharide to monosaccharides, which after derivatization (mostly by trimethylsilylation) are analysed by GC/MS. [221] Monosaccharide identification is based on comparison of retention time and fragmentation pattern with references. 

In another approach, Hindsgaul et al. reported a combinatorial strategy to obtain glycohybrids (Scheme 5) [8]. Glycohybrids are derived from monosaccharides via a Michael reaction, followed by the derivatization of the carbonyl group with several amino acids. This chemistry was further extended to the solution phase parallel synthesis to obtain a library of several compounds. 

A polar stationary phases such as ODS and TMS and polar such as CN, diol, or NO2 have been successfully applied to the separation of monosaccharides Separation of maltodextrin derivatized with trifluoroacetic anhydride using FID and a CN packed column Capillary supercritical fluid chromatography-MS is well suited to confirm the identity of the TMS derivative of inositol triphosphate Chiral analytes Enantioseparation... 

An elegant alternative approach for noncovalent interaction relies on fluorous-lluorous interactions. A glycan array of monosaccharides and disaccharides bearing anomeric fluorous tags was noncovalently immobilized on fluorous-derivatized glass slides (19, 20). The attachment method is compatible with a wide range of functional groups and has been successfully used to probe carbohydrate-protein interactions. 

The use of gas chromatography requires volatile compounds, of course, and derivatives must be made of the hydrolyzed monosaccharides. Many investigators have used methylation or acetylation to produce these derivatives (10,16). However, both of these methods require more steps than are desirable with a small sample. In addition, the reaction time required for quantitative conversion to the derivative may be a problem. The use of trimethylsilyl ethers makes the derivatization exceedingly simple and relatively fast. Formation of these derivatives in the absence of water has been shown to occur without anomerization and to proceed quantitatively (30,31). The reaction mixture is chromatographed directly (Figure 9). 

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