Nuclear magnetic resonance enhancement

V. Vitzthum, M.A. Caporini, G. Bodenhausen, Solid-state nitrogen-14 nuclear magnetic resonance enhanced by dynamic nuclear polarization using a gyrotron, J. Magn. Reson. 205 (2010) 177-179. 

Morris G A and Freeman R 1979 Enhancement of nuclear magnetic resonance signals by polarization transfer J. Am. Chem. See. 101 760-2... 

Ward H R and Lawler R G 1967 Nuclear magnetic resonance emission and enhanced absorption In rapid organometalllc reactions J. Am. Chem. Soc. 89 5518-19... 

Bowers, C. R., Sensitivity enhancement utilizing parahydrogen. In Grant, D.M., Harris, R. K. (Eds.), Encyclopedia of Nuclear Magnetic Resonance, Volume 9, 2002, p.l. 

Retention of a protein or protein activity after 105,000y, 1 hr Chromatography on gel filtration columns with large pore sizes Electron microscopy—however, sample preparation may partially reconstitute membranes Decrease in solution turbidity, which may be detected by a diminution in light scattering or an enhancement in light transmission Diffusion of membrane lipids as assayed by nuclear magnetic resonance and electron spin resonance... 

Example Isotopic enrichment is a standard means to enhance the response of an analyte in nuclear magnetic resonance (NMR). Such measures gain importance if extremely low solubility is combined with a large number of carbons, as is often the case with [60]fullerene compounds. [19] The molecular ion signals, IVT, of Qo with natural isotopic abundance and of C-enriched Cgo are shown below (Fig. 3.11 for EI-MS of [60]fullerenes cf. Refs. [20-22]). From these mass spectra, the enrichment can be determined by use of Eq. 3.1. For Qo of natural isotopic abundance we obtain Mrceo = 60 x 12.0108 u = 720.65 u. Applying Eq. 

Nerdal, W. and Andersen, 0.M., Intermolecular aromatic acid association of an anthocyanin (petanin) evidenced by two-dimensional nuclear Overhauser enhancement nuclear magnetic resonance experiments and distance geometry calculations, Phytochem. Anal, 3, 182, 1992. 

Fig. 5. The 13C nuclear magnetic resonance line widths of the (enriched) choline methyl resonances in dipalmitoylphosphatidylcholine (A) and in dielaidoylphosphatidylcholine (O), as a function of temperature. Spectra taken at 90.5 MHz similar results were also obtained at 25.2 MHz. Note that the higher-melting lipid, dipalmitoylphosphatidylcholine, shows a readily observable enhanced line broadening at temperatures TU 32°C, corresponding to the onset of the lateral phase separation. (Data from Ref. 4.) [Reprinted with permission from P. Brulet and H. M. McConnell, J. Am. Chem. Soc., 98, 1314 (1977). Copyright by American Chemical Society.]...

Use of an integrated system incorporating CCC separation, PDA detector, and LC-MS proved to be a valuable tool in the rapid identification of known compounds from microbial extracts.6 This collection of analytical data has enabled us to make exploratory use of advanced data analysis methods to enhance the identification process. For example, from the UV absorbance maxima and molecular weight for the active compound(s) present in a fraction, a list of potential structural matches from a natural products database (e.g., Berdy Bioactive Natural Products Database, Dictionary of Natural Products by Chapman and Hall, etc.) can be generated. Subsequently, the identity of metabolite(s) was ascertained by acquiring a proton nuclear magnetic resonance ( H-NMR) spectrum. 

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