Oligosaccharides compositional analysis

The introduction of g.l.c. for oligosaccharide analysis constituted a major breakthrough in the field. In addition to strategies for accurate and sensitive quantitation of monosaccharide type (19,20), chiral procedures may be adopted for enantiomeric (d and l) determination (21). The sensitivity of h.p.a.e. chromatography with pulsed amperometric detection now provides an alternative to g.l.c. for oligosaccharide compositional analysis (22). 

For monitoring the extent of polysaccharide hydrolysis, l.c. methods that sepeu ate and analyze the non-fermentable oligosaccharides (d.p. 3-30) derived from cellulose, hemicellulose, and pectins are useful, and have already been described (see Section III,l,c). For determination of the monosaccharide composition of completely hydrolyzed, plant polysaccharides, l.c. is especially useful and has been applied to the compositional analysis of hydrolyzed plant fiber,wood pulps,plant cell-walls,and cotton fibers.In these representative examples, the major sugars of interest, namely, glucose, xylose, galactose, arabinose, and mannose, have traditionally been difficult to resolve by l.c. The separa-... 

Monosaccharide composition analysis of the intact MAb revealed monosaccharide ratios consistent with the presence of lactosamine type, fucosylated biantennaiy oligosaccharides with less than complete galactosylation (gal man is < 2 3) (Table 1). 

An important step in the characterization of oligosaccharides may be the compositional analysis with respect to the type of monomeric units present. This is mostly done using methylation of the monomers after methanolysis or hydrolysis of the oligosaccharides and subsequent GC-MS analysis [5]. Permethylation of intact oligosaccharides can also be applied prior to ESl-MS analysis, in most cases using dimethylsulfoxide/NaOH and methyliodide [6]. The number of methyl substituents added to each sugar unit in an oligosaccharide is indicated in Table 20.1. 

Mass spectrometry of GAG oligosaccharides MS can be used to confirm SAX-HPLC findings or to elucidate the compositional analysis a... 

F.a.b.-m.s. has contributed to a detailed analysis of the high-mannose carbohydrate chains of prostaglandin endoperoxide synthase from sheep. Oligosaccharides released by hydrazinolysis were analyzed after N-re-acetylation and reduction. The f.a.b. data defined the compositions of the oligosaccharides, and showed that hydrazinolysis had effected a partial fission of the chitobiose core. 

In a study completed during the early development of f.a.b.-m.s., both f.d. and f.a.b. were used to characterize 101 fractions containing neutral oligosaccharides isolated from human milk. Samples were examined as their peracetylated alditols. In subsequent work, the structures of two minor acidic oligosaccharides from human milk were investigated. The per-methylated derivatives were analyzed by f.a.b.-m.s., and their compositions and sequences were defined by the f.a.b. data. Methylation analysis and partial formolysis were the other principal methods used. 

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