Carbon-13 and proton NMR analysis of isotopically labeled benzo[a]pyrenes

1983 ◽  
Vol 105 (4) ◽  
pp. 733-735 ◽  
Author(s):  
Clifford J. Unkefer ◽  
Robert E. London ◽  
Thomas W. Whaley ◽  
Guido H. Daub
Keyword(s):  
Proton Nmr ◽  
Nmr Analysis

scholarly journals NMR lipid profiles of cells, tissues, and body fluids: proton NMR analysis of human erythrocyte lipids.

1994 ◽  
Vol 35 (11) ◽  
pp. 1925-1931
Author(s):  
R K Adosraku ◽  
G T Choi ◽  
V Constantinou-Kokotos ◽  
M M Anderson ◽  
W A Gibbons
Keyword(s):  
Human Erythrocyte ◽  
Proton Nmr ◽  
Body Fluids ◽  
Lipid Profiles ◽  
Nmr Analysis ◽  
Erythrocyte Lipids

The chemistry of 2-methyltetrahydropyran-4-one: An L-Selectride reaction that gives predominantly the equatorial alcohol

1978 ◽  
Vol 56 (6) ◽  
pp. 789-793 ◽  
Author(s):  
Donald C. Wigfield ◽  
Steve Feiner
Keyword(s):  
Proton Nmr ◽  
Reducing Agents ◽  
Cyclic Ether ◽  
Nmr Analysis ◽  
Ether Oxygen

The stereoisomers of 2-methyltetrahydropyran-4-ol have been separated and identified by carbon-13 and proton nmr analysis of the trideuteriomethyl-2,6,6-trideuterio analogue. Stereoisomeric product ratios of reduction of 2-methyltetrahydropyran-4-one (1) by NaBH4, KBH4, L-Selectride, K-Selectride, and LiBH(nBu)3 have been determined and compared with reductions of 3-methylcyclohexanone. Product ratios in the reduction of the two substrates by the borohydride reducing agents are similar but are quite different in the reduction by the Selectride reducing agents, 1 being reduced by Selectride to give 73% equatorialalcohol. Two possible mechanisms of reduction of 1 are proposed, involving intramolecular assistance by the cyclic ether oxygen.

Proton NMR analysis of plasma is a weak predictor of coronary artery disease

2006 ◽  
Vol 12 (6) ◽  
pp. 705-710 ◽  
Author(s):  
Heide L Kirschenlohr ◽  
Julian L Griffin ◽  
Sarah C Clarke ◽  
Ranyl Rhydwen ◽  
Andrew A Grace ◽  
...  
Keyword(s):  
Coronary Artery Disease ◽  
Coronary Artery ◽  
Proton Nmr ◽  
Nmr Analysis ◽  
Artery Disease

A Quantitative NMR Method for Silyllithium Analysis

Synlett ◽  
2017 ◽  
Vol 28 (18) ◽  
pp. 2449-2452
Author(s):  
Scott Sieburth ◽  
Yingjian Bo
Keyword(s):  
Proton Nmr ◽  
Relative Quantification ◽  
Nmr Analysis ◽  
Quantitative Nmr ◽  
Simple Method ◽  
Nmr Method

A rapid and extremely simple method for silyl anion analysis is presented. The progress of silyllithium reagent preparation can be determined by quenching an aliquot with neat chloro(trimethyl)silane, evaporation, dilution with CDCl3, and direct proton NMR analysis. This procedure is fast, simple, and allows for identification and relative quantification of the starting reagent, intermediates, and the silyllithium product.

Ex Vivo Proton NMR Analysis and Characterization of Thymus Lipid Metabolites and their Variation with Age in C57BL/6 Mice

2011 ◽  
Vol 4 (1) ◽  
pp. 57-69
Author(s):  
Iago Pinal-Fernandez ◽  
Manuel Martin-Pastor ◽  
Pedro Ferro-Gallego ◽  
Lourdes Dominguez-Gerpe
Keyword(s):  
Ex Vivo ◽  
Proton Nmr ◽  
Nmr Analysis ◽  
Lipid Metabolites

A proton NMR analysis of the OCH3 group conformation in 2-methoxypyridines

1982 ◽  
Vol 20 (1) ◽  
pp. 40-41 ◽  
Author(s):  
R. H. Contreras ◽  
J. C. Facelli ◽  
D. G. de Kowalewski
Keyword(s):  
Proton Nmr ◽  
Nmr Analysis ◽  
Och3 Group

scholarly journals Absolute Quantification of Choline-Related Biomarkers in Breast Cancer Biopsies by Liquid Chromatography Electrospray Ionization Mass Spectrometry

2013 ◽  
Vol 36 (3-4) ◽  
pp. 71-83 ◽  
Author(s):  
Maria Chiara Mimmi ◽  
Nicoletta Finato ◽  
Gloria Pizzolato ◽  
Carlo Alberto Beltrami ◽  
Federico Fogolari ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Mass Spectrometry ◽  
Liquid Chromatography ◽  
Electrospray Ionization ◽  
Electrospray Ionization Mass Spectrometry ◽  
Proton Nmr ◽  
Absolute Quantification ◽  
Ionization Mass Spectrometry ◽  
Ionization Mass ◽  
Nmr Analysis

It has been repeatedly demonstrated that choline metabolism is altered in a wide variety of cancers. In breast tumours, the choline metabolite profile is characterized by an elevation of phosphocholine and total choline-compounds. This pattern is increasingly being exploited as biomarker in cancer diagnosis.The majority of in vitro metabolomics studies, for biomarkers quantification in cell cultures or tissues, entail proton NMR spectroscopy. Although many “targeted” approaches have been proposed to quantify metabolites from standard one-dimensional (1D) NMR experiments, the task is often made difficult by the high degree of overlap characterizing 1H NMR spectra of biological samples.Here we present an optimized protocol for tissue extraction and absolute quantification of choline, phosphocholine and glycerophosphocholine by means of liquid chromatography electrospray ionization mass spectrometry (LC-ESI-MS). The selected chromatographic separation system with a HILIC (hydrophilic interaction chromatography) amide column effectively separates free choline and its phopshorylated derivatives, contrary to failure observed using standard reversed-phase chromatography. The metabolite absolute quantification is based on external calibration with commercial standards, and is validated by a parallel 1D proton NMR analysis.The LC-MS/NMR analysis is applied to three breast carcinoma specimens obtained by surgical excision, each one accompanied by a control tissue sample taken outside the tumor margin. The metabolite concentrations measured are in good agreement with previous results on metabolic profile changes of breast cancer. Each of the three cancerous biopsies, when compared with the control tissue, exhibit a highly increased levels phosphocholine, total choline and phosphocholine/glycerophosphocholine ratio.

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