Oligosaccharides traditional methods

One of the applications of CE for carbohydrate analysis that has shown increase acceptance in the biotechnology industry is the relative distribution of the N-linked oligossacharides on the conserved asparagines residue on the Fc portion of rMAbs. The advantages of CE over traditional methods include enhanced separation efficiencies, shorter analysis time, and improved robustness. The oligosaccharides present on a monoclonal antibody are asialo-N-linked complex biantennary structures with a core fucose, typical of the structures produced in the Chinese hamster ovary (CHO) cells. The main forms share the fucosylated branched core structure but vary in their terminal galactose occupancy ... 

Recently, numerous approaches have been studied for the development of cheaper and most effective adsorbents containing biopolymers. The most widespread biopolymers are polysaccharides [190], chitin [167, 139, 7] and cyclodextrin [157, 26, 32]. These biopolymers reach the increasing demand for treatment of industrial wastewater before their use or disposal. Because the pollutants creates environmental and health diffieulties, associated with heavy metals and pesticides and their deposit through the food chain [39]. Traditional methods for the elimination of heavy metals from industrial wastewater may be inefficient or costly, particularly when metals are present at low concentrations [30, 184]. Chitin, chitosan and oligosaccharides represent interesting and attractive alternative adsorbents because of their particular structure, physico-chemical characteristics, chemical stability, high reactivity and excellent selectivity towards metals. Moreover, Ihey are abundant, renewable and biodegradable resources and have a capacity to associate by physical and chemical interactions with a wide variety of molecules [22, 131]. 

In addition, a novel fluorous support has been developed recently as an alternative to traditional polymer supports and applied successfully to oligosaccharide synthesis in combination with the trichloroacetimidate method [541]. Each intermediate in the fluorous oligosaccharide synthesis [542,543] could be obtained by simple fluorous-organic solvent extraction, and the reactions could be monitored by TLC, NMR and MS, in contrast to solid-phase reactions. Moreover, the new liquid-phase technique is anticipated to be easily applicable to the large-scale synthesis. 

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-... 

NMR spectroscopy has developed during the last few years into a very powerful method to establish both the conformation of an oligosaccharide in solution and in the crystalline state. The solution conformation of a saccharide can be determined generally by the combination of 13C-NMR and H-NMR techniques. 2-d methods became available in the last few years and are prerequisites for the elucidation of the three dimensional structure of an oligosaccharide [7]. Both NOE measurements [21] as well as traditional determination of coupling constants and chemical shifts are important tools for the determination of preferred conformations. 2-dimensional methods have greatly improved the accessibility of these parameters from complex molecules. 

Traditionally, homonuclear 2D double quantum filtered correlation spectroscopy (DQF-COSY) and total correlated spectroscopy (TOCSY) spectra are valuable in the identification of resonances of individual monosaccharide units. In the presence of small couplings, through space connectivities detected by NOESY/ROESY (nuclear Overhauser effect spectroscopy/ rotational nuclear Overhauser effect spectroscopy) experiments are also useful in completing the resonance assignment. When the H NMR spectra of complex oligosaccharides are too crowded to fully elucidate the structure by homonuclear correlation methods, it is efficient to use 2D heteronuclear correlation methods, such as heteronuclear single quantum correlation... 

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