Carbohydrates structural analysis

Other than a brief collaboration with S. AronofF, A. Benson, and M. Calvin (1947) on the distribution of label in photosynthesizing plant-tissue, this short sojourn by Hassid in the field of photosynthesis was not continued, and his involvement appears to have been based more on an interest in carbohydrate structural analysis than in the fundamentals of carbon fixation in plants. However, it is apparent from the later turn of events that this introduction to the utility of radioactive-tracer techniques for the elucidation of biochemical processes had a strong influence on his development. 

The main emphasis of current carbohydrate structural analysis is the applicability of modern multi-dimensional NMR for solving the two crucial problems in complex carbohydrate structural analysis, namely, the elucidation of the sequence of glycosyl residues and the solution conformation and dynamics of a carbohydrate (150). Techniques include 2D Total Correlation Spectroscopy (TOCSY), Nuclear Overhauser effect spectroscopy (NOESY), rotational nuclear Overhauser effect spectroscopy (ROES Y),hetero-nuclear single quantum coherence (HSQC), heteronuclear multiple quantum correlation (HMQC), heteronuclear multiple bond correlation (HMBC), and (pseudo) 3D and 4D extensions. 

G. R. Gray, New technology for carbohydrate structural analysis, Abstr. Carb. 24, 221st ACS National meeting, San Diego, CA (2001, April 1-5). 

Fractionated LCC [22] 5 + 2 Suitable to address LCC heterogeneities in terms of lignin and carbohydrates structures analysis of LCC linkages is problematic... 

G. Lochnit and R. Geyer, Carbohydrate structure analysis of batroxobin, a thrombin-like serine protease from Bothrops moojenrvenom. Eur. J. Biochem., 1995, 228, 805-816. 

Novel and potentially important applications of vibrational Raman optical activity studies to carbohydrate structure analysis have also been reported. Within the region 600-1600 cm this technique serves to reflect local stereochemical details (generated as a result of short-range interactions). Information relating to anomeric configuration is found at 750-950 cm, and 950-1200 cm provides a fingerprint characteristic of ring structure and substitution pattern. Above 12(X) cm, spectra are dominated by CH2 and C-OH deformations which provide useful data on the conformational preference of exocyclic hydroxymethyl units. 

This chapter is divided into two parts The first and major portion is devoted to carbohydrate structure You will see how the principles of stereochemistry and confer matronal analysis combine to aid our understanding of this complex subject The remain der of the chapter describes chemical reactions of carbohydrates Most of these reactions are simply extensions of what you have already learned concerning alcohols aldehydes ketones and acetals... 

The groundwork has now been laid for the exploitation of f.a.b.-m.s. by all carbohydrate chemists involved with the structural analysis of novel compounds. There is no reason why f.a.b.-m.s. should not take its place alongside g.l.c.-m.s., e.i.-m.s., and c.i.-m.s. as a relatively routine, analytical procedure. It is important, however, that f.a.b.-m.s. be integrated into sensible structural strategies, and that it be very closely linked to the chemical manipulations that are also being conducted as part of the structural program. 

PROTON SPIN-LATTICE RELAXATION RATES IN THE STRUCTURAL ANALYSIS OF CARBOHYDRATE MOLECULES... 

Proton Spin—Lattice Relaxation Rates in the Structural Analysis of Carbohydrate Molecules in Solution... 

V. Structural Analysis of Glycopeptides and Glycoproteins Containing Unusual Carbohydrate-Protein Linkages... 

Vliegenthart, J.F.G., Dorland, L., and van Halbeek, H. (1983) High-resolution, lH-nuclear magnetic resonance spectroscopy as a tool in the structural analysis of carbohydrates related to glycoproteins. Adv. Carbohydr. Chem. Biochem. 41, 209-374. 

Multiple-ion monitoring is, however, of considerable value in structural studies, but only if model compounds of known structure are available for comparison. Such an approach has been used in the study of the carbohydrate structures of glycoproteins from different tissues.50 Separation of glycopeptides obtained from various tissues was performed on columns of concanavalin A-Sepharose. Structural analysis by multiple-ion monitoring of partially methylated, alditol acetates derived from the various fractions indicated that the glycopeptides were separated according to the linkage pattern of mannose (see Fig. 1). 

Anhydrous hydrogen fluoride, application of for the structural analysis of polysaccharides, 47, 167-202 Anomeric and exo-anomeric effects in carbohydrate chemistry, 47, 45-123 Anomeric-oxygen activation for glycoside synthesis, trichloroacetimidate method, 50,21-123... 

In recent years, C-NMR spectroscopy has found extensive use in studies on carbohydrate polymers, in some series overshadowing the importance of H-NMR spectroscopy. Applications range through determination of primary structure, analysis of mixtures, monitoring of chemical and enzymic transformations or of chelation reactions, and studies on conformational change. Measurements of coupling are utilized in determining the... 

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