Constants of carbohydrates

Table II. Signs of Proton-Proton Constants of Carbohydrate Derivatives...

From a study (29) of the relative signs of various H, H coupling constants of carbohydrate derivatives it is evident that the couplings... 

DEVELOPMENTS IN THE KARPLUS EQUATION AS THEY RELATE TO THE NMR COUPLING CONSTANTS OF CARBOHYDRATES... 

K. Bock and C. Pedersen, Solvent effects on one-bond, C- H coupling constants of carbohydrates, Carbohydr. Res., 71 (1979) 319-321. 

B. Coxon, Developments in the Karplus equation as they relate to the NMR coupling constants of carbohydrates. Advances in carbohydrate chemistry and biochemistry 62 (2009), 17-82. 

Adds of carbohydrate origin which are constantly produced by living systems and are not considered as waste products. 

Kasaai M.R. 2007. Calculation of Mark-Houwink-Sakurada (MHS) equation viscometric constants for chitosan in any solvent-temperature system using experimental reported viscometric constants data. Carbohydrate Polymers 68, 477-488. 

Beau has applied the DCC concept to a number of carbohydrate systems [13-16]. Carbohydrate-binding proteins often exhibit weak ligand interactions with millimolar dissociation constants, a quite different scenario to the enzyme-small molecule DCLs discussed thus far. The protein target initially chosen for study was hen egg-white lysozyme (HEWL), a glycosidase known to bind A-acetyl-o-glucosamine (d-G1cNAc) with... 

Ester-type dimers illustrate the four-step approach for identification of carbohydrate structural elements in the oligosaccharide cores by NMR spectroscopy. Eor these type of compounds, edited NMR sub-spectra have permitted the assignment of all of the resonances in both monomeric units (22, 78). Spectroscopic simulation of the coupling constants can be deduced for proton resonances with a non-first-order resolution. Figure 2 illustrates this approach for batatin 1 (230) the... 

It is used in IC systems when the amperometric process confers selectivity to the determination of the analytes. The operative modes employed in the amperometric techniques for detection in flow systems include those at (1) constant potential, where the current is measured in continuous mode, (2) at pulsed potential with sampling of the current at dehned periods of time (pulsed amperometry, PAD), or (3) at pulsed potential with integration of the current at defined periods of time (integrated pulsed amperometry, IPAD). Amperometric techniques are successfully employed for the determination of carbohydrates, catecholamines, phenols, cyanide, iodide, amines, etc., even if, for optimal detection, it is often required to change the mobile-phase conditions. This is the case of the detection of biogenic amines separated by cation-exchange in acidic eluent and detected by IPAD at the Au electrode after the post-column addition of a pH modiher (NaOH) [262]. 

The work discussed in this article serves to illustrate the applicability of gel chromatography to a wide variety of carbohydrates. The technique can be used not only as a means of fractionation but also, provided that the relationship between molecular weight and such other molecular parameters as size and shape remains constant, as a method of estimating the molecular weights of polysaccharides. Often, information derived from gel chromatography has proved useful in structural elucidation. 

TABLE 15-2 Equilibrium Constants, Mass Action Coefficients, and Free-Energy Changes for Enzymes of Carbohydrate Metabolism... 

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