Glucose spectroscopic studies

VO(acac)2 < VO(Et-acac)2 VO(Me-acac)2 BMOV. Conversion rates for all hydrolysis products were faster than for the original species. Both EPR and visible spectroscopic studies of solutions prepared for administration to diabetic rats ocumented both a salt effect on the species formed and formation of a new halogen-containing complex. The authors concluded that vanadium compound efficacy with respect to long-term lowering of plasma glucose levels in diabetic rats traced the concentration of the hydrolysis product in the administration solution. 

A brief overview about the fundamental principles of the pathogenesis of skeletal muscle insulin resistance and its contribution to the development of type 2 diabetes mellitus is given in the following. Priority is given to the role of lipid metabolism, which is the main field of the reported spectroscopic studies. Furthermore, the technique of euglycemic hyperinsulinemic glucose clamp is described allowing determination of the individual insulin sensitivity of musculature. The role of IMCL in insulin resistance of the skeletal muscle is discussed. 

Hassel B, Sonnewald U, Fonnum F (1995a) Glial-neuronal interactions as studied by cerebral metabolism of [2- C]acetate and [l- C]glucose. An ex vivo C NMR spectroscopic study. J Neurochem 64 2773-2782. 

Nuclear magnetic resonance (NMR), irrfrared (IR) and optical rotary dispersion (ORD) spectroscopy studies have demonstrated that D-glucopyranose units have the same conformation in both dimethyl sulfoxide (DMSO) and heavy water (D2O). The spectroscopic studies on CDs in aqueous solution suggest that the conformation of CDs in the solution is almost identical to their conformation in the crystalline state. j8-CDs have perfect symmetry, while a- and y-CDs rings are slightly distorted. The planar structure of a-CDs in solution deviates by about 100 pm from that in the crystal structure. The twist form observed experimentally in the glucose unit number five out of the plane of the five other glucose units disappears in solution [4,9]. 

Infrared spectroscopic studies of glucose oxidase (Parker, 1962a), invertase (Parker, 1962fc), and )S-glucosidase (Parker, 1964) in aqueous solutions have been reported. In the case of the latter two enzymes, kinetic studies were done (see also, Parker, 1967). The substrate used with )S-glucosidase was phenyl )S-D-glucoside. Rate constants were calculated from absorbance data of the free-glucose band at 1149 cm . 

Nonpulsatile optical spectroscopy has been used for more than half a century for noninvasive medical assessment, such as in the use of multiwavelength tissue analysis for oximetry and skin reflectance measurement for bilirubin assessment in jaundiced neonates. These early applications have found some limited use, but with modest impact. Recent investigations into new nonpulsatile spectroscopy methods for assessment of deep-tissue oxygenation (e.g., cerebral oxygen monitoring), for evaluation of respiratory status at the cellular level, and for the detection of other critical analytes, such as glucose, may yet prove more fruitful. The former applications have led to spectroscopic studies of cytochromes in tissues, and the latter has led to considerable work into new approaches in near-infrared analysis of intact tissues. 

X-Ray irradiation of polycrystalline sodium and barium salts of D-glucose 1-and 6-phosphate and of D-ribose 5-phosphate produced P03 radicals, as evidenced by ESR spectroscopic studies no precursor phosphoranyl radicals were detected. ... 

Apart from the number of theoretical studies on n-glucopyranose [257, 258], only one vibrational spectroscopic study of a-D-glucopyranose isolated in Ar matrix has been reported [259]. Laser spectroscopy through UV—UV and IR—UV doubleresonance techniques has contributed to the description of the conformations of some p-phenylglucopyranosides and their hydrates [219, 220, 260, 261] but these studies are limited to vibrational resolution and the structural conclusions are not totally transferable to D-glucose because of the electronic chromophore at the anomeric position. 

The specific volumes and coefficients of refraction have been calculated for aqueous solutions of sucrose at several temperatures. Self-diffusion coefficients have been reported for sucrose, sodium D-glucuronate, and 2-amino-2-deoxy-D-glucose hydrochloride in aqueous solution. The triboluminescence (i.e. luminescence caused by mechanical stress) of crystalline mono- and di-saccharides has been studied this phenomenon was shown by some sugars (e.g. sucrose and D-glucose) but not by others (e.g. cellobiose and D-mannose). An e.s.r. spectroscopic study of D-glucose, D-mannose, D-galactose, D-fructose, and methyl... 

Xylitol reacted with boric acid under reduced pressure to give mixtures of boric esters and polymeric xylitol-borate complexes, and a cryoscopic study of the borate complexes formed by pentaerythritol has been reported. N.m.r. spectroscopic studies have confirmed that borax complexes with HO-1 and -2 and with HO-3, -5, and -6 of D-glucose in the a-furanose form to give bidentate and terdentate complexes, respectively. Only those D-glucobioses that are (1 3)- or (1 6)-linked formed complexes with borax. 

These are some examples of the use of i.r. spectra in the analysis and identification of carbohydrates in foods and natural products. Very often, these spectroscopic techniques are complementary to others, such as the study of aldobiouronic acids obtained by hydrolysis of peach-gum polysaccharides by their optical rotations and their i.r. spectra.100 However, the i.r. results appear to be sufficiently reliable to be used in the detection of traces of fructose and glucose, and to determine the d.e. (dextrose equivalent) of corn syrups, as well as the quantitative carbohydrate content in different products.101... 

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