Glucose proton resonance spectrum

Figure 2.17 Application of the reverse DEPT pulse sequence to monitor C-labeled glucose by mouse liver-cell extract. (A) Normal FT spectrum. (B) Reverse DEPT spectrum showing the a- and )3-anomeric proton resonances. (C) Two different CH2 proton resonances, a and b, appear after 1.5 h of metabolism. (D) Edited H spectrum confirming that the CH2 resonances arise from metabolic products. (Reprinted from J. Magn. Resonance 56, Brooks et al., 521, copyright 1984, Academic Press.)...

Fig. 3.5 Expansion of a selective decoupled spectrum (top trace) and normal spectrum (bottom trace) of peracetylated glucose. Proton H-C(5) with resonance at 3.85 ppm has been decoupled.

Fig. 9.—Proton Magnetic Resonance Spectrum of l,2,3, 4,6-Penta-0-acetyl-3-deoxy-3-C-(hydroxymethyl)-a-D-glucose in CDCI3 at 100 MHz.

Fig. 8.—The Partial, H Nuclear Magnetic Resonance Spectrum of Sucrose Octaacetate (8) in Solution in Acetone-rid, With a Diagrammatic Representation of the First-order Assignment of the n-Glucose Protons is Shown in A. [The set of INDOR traces (B, C, D, and E) was obtained by sequentially monitoring transitions 1, 8, 5, and 3.]...

Figure 1 shown below is the proton NMR spectrum of an acid hydrolyzed sample of a fast-growing species of willow (Salix spp.). Although the spectral region from 3.2-4.0 ppm is veiy complex, the well resolved resonances centered near 5.2 ppm and 4.6 ppm can be assigned to the a and p anomeric Cl protons of D-glucose and D-xylose. The higher intensity resonance of each pair is D-... 

Physical characterization of a SCL-MCL PHA copolymer produced from glucose in recombinant E. coli expressing fatty acid biosynthesis enzymes and PHA synthase. The isolated polymer produced by frtty acid biosynthetic enzymes and a mutant PHA synthase was characterized by NMR, gel permeation chromatography (GPC), and differential scanning calorimetry (DSC). In order to determine the structure of the isolated polymer and to show that the polymer was a true copolymer rather than a blend of polymers, NMR was used. The mol% fractions of the secondary (C6) and tertiary (C8) monomer units were determined from the intensity ratio of tiie main-chain methylene proton resonance to methyl proton resonance in the H NMR spectra (Figure 3A). Supporting information for tertiary (C8) monomer units were obtained by C NMR analysis. As shown in Figure 3B, the C NMR spectrum was used to show that the polymer was a random copolymer rather than a blend of polymers. 

The widespread occurrence of long-range couplings in both furanose and pyranose derivatives explains why so many of the P.M.R. spectra of carbohydrate derivatives are apparently poorly resolved, even when the resolution of the spectrometer is above reproach. For example, the Hi resonance of the 1,6-anhydro-D-glucose derivative (12) is coupled to all of the other six ring protons. A further example of the line-broadening effect follows a consideration of the spectrum of 5,6-dideoxy-5,6-epithio-l,2-0-isopropylidene-/ -L-idofuranose for which the half-height... 

Fig. 3.9 Expan.sion of the ID NOE Spectra of peracetylated glucose Top trace -Unperturbed reference spectrum. Bottom trace - Difference spectrum. Proton H-C(6) with resonance at 4.3 ppm has been selectively saturated.

Load the proton spectrum of peracetylated glucose D NMRDATA GLUCOSE 1D H GH 002999,1R and expand a methyl resonance. From the Analysis pull-down menu choose the Linewidth option. With the cursor in Maximum Cursor mode, select a resonance line by clicking the left mouse button. With the cursor set on the top of the peak, click the right mouse button. A horizontal line indicates the intensity at half height and the corresponding line width (in Hz) will appear below the title bar. 

The DQF-COSY spectrum for lactose (Figure 5.21) is rich with correlations, and entry points are easy to find. This figure and others of lactose use a simplified notation in which galactose resonances are labeled Gn, where n is the proton or carbon position, and either an or fin for positions in the a-glucose residue and the /3-glucose residue, respectively. Each of the anomeric protons, which are the protons attached to C-l for each sugar residue, show one and only one correlation to their respective C-2 protons. For instance, the anomeric proton at 4.67 ppm shows a correlation to a proton (obviously attached to C-2) at 3.29 ppm. This C-2 proton at 3.29 ppm shows a correlation to a C-3 proton at 3.64 ppm. 

The HMQC-TOCSY spectrum for lactose is given in Figure 5.28 with all of the proton and carbon resonances labeled. The overall appearance of this spectrum is reminiscent of an HMBC but the correlations are quite different. It is equally interesting and useful to start on the proton axis (F2) or the carbon axis (FI). If we start on the proton axis at 5.23 ppm, the anomeric proton for the a-anomer of glucose (ad), and proceed downward vertically, we find six correlations to the six carbons of this glucose residue. If we refer back to the simple HMQC spectrum for lactose, we find only one correlation for this proton. Likewise, the anomeric proton of the /3-anomer of glucose at 4.67 ppm also shows six correlations to the carbons of its respective glucose residue. 

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