Polysaccharides methodologies

For polysaccharides composed of oligosaccharide repeating units, the structural studies may ultimately lead to a complete structure. Other polysaccharides have less-ordered structures, and the aim of the structural studies should be to define the factors governing these structures. Polysaccharide methodology has been summarized2 in two review articles. 

Polysaccharide methodology, with particular emphasis on such analytical techniques as g.l.c., m.s., and and n.m.r. spectroscopy and on fragmentation procedures, has been reviewed. ... 

Modem Methodology of Structural Polysaccharide Chemistry, M. Stacey, Chem. Br., 6 (1970) 113-118. 

D. A. Brant and T. A. Talashek, in Industrial Polysaccharides The Impact of Biotechnology and Advanced Methodologies, Gordon and Breach Science Publishers, New York (1987). 

Carbohydrates and polysaccharides, on the one hand, and peptides and proteins, on the other, have been considered as separate classes of natural products for a long time. Fundamental chemical methodology for the synthesis of both saccharides and peptides was developed by Emil Fischer et al. at the beginning of the 20th century. 1,2 However, the harsh conditions employed in early solution and solid-phase peptide synthesis hindered the combination of peptide and carbohydrate chemistry, i.e. glycopeptide synthesis. Considerable efforts were made to combine the two branches of natural product chemistry, and the state of the art within glycopeptide synthesis has improved dramatically during the last decades, as described in a number of reviews. 3 23,512"514 ... 

Nuclear magnetic resonance (NMR) spectroscopy is a very powerful tool for analyzing the conformation and molecular architecture of carbohydrate molecules. Both one- and two-dimensional (ID and 2D) methodologies have provided valuable information about small and large molecules, ranging from the anomeric configuration of a monosaccharide to the sequence of monosaccharide residues that constitute an oligo- or polysaccharide. 

The application of static light scattering to polymers is based on the theoretical equations of Debye (1944, 1947) and the methodology of Zimm (1948). The principles apply equally to polysaccharides (Sorochan et al., 1971). In total intensity light scattering, monochromatic light (436 and 546 nm) at constant T passes through the dispersion and becomes plane polarized the horizontal beam is scattered in accordance with the equation (Hiemenz, 1986)... 

Carbohydrates in algae and plants are often classified based on methodological discrimination. The structural carbohydrates are not water-soluble, whereas the other types of carbohydrates are water-soluble and typically extracted by hot water. In Phaeocystis five different pools of carbohydrates can be distinguished. Like all algal and plant cells, both solitary and colonial cells produce (1) structural carbohydrates, polysaccharides that are mainly part of the cell wall, (2) mono- and oligosaccharides, which are present as intermediates in the synthesis and catabolism of cell components, and (3) intracellular storage glucan. Colonial cells of Phaeocystis excrete (4) mucopolysaccharides, heteropolysaccharides that... 

After their isolation by chromatographic techniques (anion-exchange chromatography, size exclusion, etc.), different analytical methodologies have been used to identify and quantify the polysaccharides in wine the most commonly used being the traditional methylation analysis followed by GC-MS (Doco and Bril-louet 1993). Polysaccharides have also been determined after solvolysis with anhydrous methanol containing HCl by GC-MS of their per-G-trimethylsilylated methyl glycosides (Vidal et al. 2003). Other techniques such as Fourier transform infrared spectroscopy (FTIR) have been more recently proposed (Coimbra et al. 2002,2005 Boulet et al. 2007). 

We extended the methodology developed for molecular characterization of cotton fiber to analysis of other polysaccharides. In this report, we present the results obtained from MWDs determined by SEC for various complex carbohydrate samples dissolved in DMAC-LiCl. Applications include cotton fiber, corn and wheat starch flours, and avocado cell walls. Relationships are evaluated between the respective MWDs and cotton fiber development, variety, inheritance, textile processing, and strength starch extrusion conditions and stage of ripening in avocado. 

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