Nuclear magnetic resonance sugar solution

Mora-Gutierrez, A., Farrell, Jr., H.M. (2000). Sugar-casein interaction in deuterated solutions of bovine and caprine casein as determined by oxygen-17 and carbon-13 nuclear magnetic resonance a case of preferential interactions. Journal of Agricultural and Food Chemistry, 48, 3245-3255. 

Since 1942 some new analytical techniques have become available for the study of sugar solutions, notably nuclear magnetic resonance spectroscopy (NMR) and gas-liquid chromatography (GLC). The NMR method is discussed elsewhere in this volume GLC-based techniques are described here. 

Tnformation about the characteristics of keto-hexoses in solution has been - derived mainly from optical rotatory data (I, 2, 3, 4) and in recent years by application of the principles of conformational analysis (5, 6). In the current study an attempt is made to describe the conformation and composition of these sugars in solution by nuclear magnetic resonance (NMR) spectroscopy, a highly sensitive means for examining stereochemistry and for differentiating between isomeric species. 

Composition of Sugar Solutions as Determined by Nuclear Magnetic Resonance Measurements ... 

In some instances, nuclear magnetic resonance techniques employing trimethylsilyl ethers have provided information on the composition of sugar solutions that could not be obtained by classical methods. Thus, the formation of D-galactofuranose during mutarotation was shown by gas chromatography of the trimethylsilyl derivatives of D-galactose (from the mutarotation mixture). The products were... 

Nuclear magnetic resonance spectroscopy gives precise information on complexation in solution. Equilibrium is rapidly established on an NMR time scale, hence only an average spectrum is observed and it is difficult to determine the spectrum of a pure complex. When complexation of a sugar or polyol with a diamagnetic ion occurs, all of the signals shift downfield. Equation (11.1) allows the variation of the shielding constant Ao- of the proton to be calculated when the nucleus is subjected to an electric field E whose projection on the C-H bond is... 

The effect of the solvent on the proportions of the anomers for sugars in solution has also been studied by Perlin and coworkers by nuclear magnetic resonance measurements (see p. 46, Part I). These workers suggested that, in aqueous solutions of D-fructose, the pyranose form is stabilized by hydrogen-bonding with water molecules. Additional data supplied by Perlin are given in Table XVII. 

The other analytical methods involving biomass composition that are currently in development (FT-IR, NIR, and pyMBMS) are able to resolve and quantify individual sugar composition. This is not possible with HR-TGA however, in conjunction with H nuclear magnetic resonance (NMR), sugar residues can be identified, and their abundance can be determined. Carbohydrate compositional profiles of lignocellulosic biomass can be accurately quantified based on the 600 MHz H-NMR spectram of unpurified acid hydrolyzates wherein the hemicellulose and cellulose ftactions of biomass have been reduced to a mixmre of sugars in acidic solution [23]. 

Solution nuclear magnetic resonance (NMR) spectroscopy was introduced by Newman and Tate (1980) to define the structural composition of soil organic phosphorus. The technique allows the identification of several inorganic phosphorus forms (phosphate, pyrophosphate, polyphosphate) and organic phosphorus forms, such as phosphate monoesters (e.g. inositol phosphates and sugar phosphates), phosphate diesters (e.g. nucleic acids, phospholipids, teichoic acids) and phosphonates. 

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