Oligosaccharides challenge

Carbohydrates and especially oligosaccharides represent a special category for NMR spectroscopists. The structural characterization of oligosaccharides by NMR spectroscopy has remained challenging because of the lack of experimental parameters and the intrinsic high mobility in solution. For instance, the conformation around the exocyclic glycosidic bonds cannot unambiguously be determined from measurement of interresidue 1H-1H NOE measurements. 

The challenge for developing methods for synthesizing oligosaccharides, notably for complex oligosaccharides, that can be scaled up to an industrial level is obvious, based on the use of substrates and enzymes that are available at reasonable cost and purity. Strategies for oligosaccharides synthesis include ... 

Not only can the synthetic strategy find applications in the construction of challenging peptides, it can also be applied for the assembly of other biopolymers, such as oligosaccharides and nucleic acids. 

The chemical synthesis of oligosaccharides is also more complicated than the synthesis of other biopolymers, because the construction of each individual oligosaccharide poses a new challenge, requiring a knowledge of methods, together with experience and experimental skill. Thus, there are no universal methods available neither for biological in vivo nor for chemical in vitro syntheses. 

A number of challenges still remain before a flexible, high-yielding, and absolutely selective strategy for the synthesis of oligosaccharides on the solid support becomes available. Once these problems are solved, the construction of an automated oligosaccharide synthesizer will become feasible. 

Amino acid Secreted by endophytic green alga A. operculata challenged with kappa-carrageenan oligosaccharides L-Asparagine... 

Omori T (1996) Substitution Reactions of Technetium Compounds. 176 253-274 Oscarson S (1997) Synthesis of Oligosaccharides of Bacterial Origin Containing Heptoses, Uronic Acids and Fructofuranoses as Synthetic Challengers. 186 171-202 Ostrowicky A, Koepp E, Vogtle F (1991) The Vesium Effect Synthesis of Medio- and Macrocyclic Compounds. 161 37-68 Otsuji Y,see Mizuno K (1994) 169 301-346 Pdlinkd I, see Tasi G (1995) 174 45-72... 

Synthesis of Oligosaccharides of Bacterial Origin Containing Heptoses, Uronic Acids and Fructofuranoses as Synthetic Challenges... 

Most ILMs are less acidic than the commonly used acidic matrices alone. This leads to the possibility to synthesize matrices with only weakly acidic or even neutral or basic pH values [48]. These matrices may be beneficial for the analysis of acid-labile compounds [40]. For example, these matrices were successfully used for the measurement of acid-labile compounds like sulphated oligosaccharides, which are a class of compounds with high biological relevance [49]. Using classical preparations, the detection of these challenging analytes was only possible after derivatization or in the form of noncovalent complexes formed with basic peptides. Upon use of the ILM,... 

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