High-resolution Carbon-13 Nuclear Magnetic Resonance Research Articles

Quantitative high-resolution carbon-13 NMR analysis of lipids extracted from the white muscle of Atlantic tuna (Thunnus alalunga)

Lipids extracted from albacore tuna were studied using high-resolution 13 C nuclear magnetic resonance (NMR) spectroscopy. Simultaneous quantitative determination of free fatty acids, lipid classes, and fatty acids α-β positional distribution in triacylglycerols win obtained. Glyceride and phospholipid composition was studied using glyceryl resonances. Lipids extracted from fresh white muscles of Atlantic tuna had a different triacylglycerol and phospholipid content, related to fish weight. Free fatty acid carbonyl resonances were detected at the lower field of the 13 C NMR carbonyl region and used for its quantitative determination

The 3'-keto-diol equilibrium of trospectomycin sulfate bulk drug and freeze-dried formulation: solid-state carbon-13 cross-polarization magic angle spinning (CP/MAS) and high-resolution carbon-13 nuclear magnetic resonance (NMR) spectroscopy studies.

Understanding how moisture interacts with a drug or formulation is a critical component of product development. This study demonstrates how water affects the 3'-gem-diol<==>3'-keto equilibrium in trospectomycin sulfate bulk drug and freeze-dried formulation, as probed by solid-state carbon-13 cross-polarization magic angle spinning (CP/MAS) and high-resolution nuclear magnetic resonance (NMR) spectroscopy. Drying the bulk drug or formulation to low water levels dehydrates trospectomycin sulfate from the diol to the keto form. Carbon-13 CP/MAS NMR spectroscopy measures the keto drug concentration in solid samples directly. The bulk drug, which contains approximately 16% water, is more than 90% in the 3'-diol form. Oven drying to < 3% water converts approximately 75% of the drug to the 3'-keto form. The drug is formulated as a freeze-dried, sterile powder that can contain up to 12% water depending on the freeze-drying conditions. These studies show that the 3'-keto concentration rises uniformly (up to 75%) with decreasing residual water in the freeze-dried cake. The keto-diol equilibrium was also studied in solution by high-resolution carbon-13 NMR experiments, and it was found that raising the temperature or using dimethyl sulfoxide (DMSO) as a solvent also dehydrates the drug. For example, in aqueous solution at 25 degrees C, nearly all (> 95%) of the drug is in the 3'-diol form. After equilibration at 60 degrees C, however, the 3'-keto content increases to 7%, and in d6-DMSO solvent at 25 degrees C the drug is mostly (60%) in the 3'-keto form.

The determination of ionic bonding interactions of N-phenyl glycine and N-(2-hydroxy-3-methacryloxypropyl)-N-phenyl glycine as measured by carbon-13 NMR analysis.

The purpose of the present investigation was to determine whether high-resolution carbon-13 nuclear magnetic resonance could be utilized for detection of ionic bonding interactions of NPG and NPG-GMA with selected inorganic cations. The C1-carbonyl carbon of NPG and NPG-GMA were labeled with 13C to help magnify the spectral response signal. The labeled monomers were allowed to react with Ca(OH)2 and LiOH. The C-13 carbonyl resonance was observed by solution- and solid-state NMR. The interaction of the cations in solution and on a powered glass support resulted in a downfield chemical shift of about 2-5 ppm, indicating the presence of a chemical interaction between the monomer and the cations. The reaction of the monomers with the solid substrates of hydroxyapatite, and bovine dentin did not result in a significant downfield shift in the carbonyl resonance. The results provide evidence that high-resolution nuclear magnetic resonance can be used for evaluation of chemical bonding interactions of dental adhesives with inorganic ions.

High-resolution carbon-13 nuclear magnetic resonance study of the soybean 7S storage protein fraction in solution

The study was undertaken toidentify the aminoacid residues of the 7S soybean protein fraction in solution and to examine the usefulness of NMR in monitoring the conformational changes and association-diassociation reactions induced by pH and ionic strength.

High-resolution carbon-13 nuclear magnetic resonance spectra and structure of amorphous and crystalline forms of stereoregular poly(methyl methacrylate)s

High-resolution carbon-13 nuclear magnetic resonance spectra and structure of amorphous and crystalline forms of stereoregular poly(methyl methacrylate)s

High-resolution carbon-13 nuclear magnetic resonance of trigonal and orthorhombic crystals of poly(oxymethylene)

High-resolution carbon-13 nuclear magnetic resonance of trigonal and orthorhombic crystals of poly(oxymethylene)

High-temperature NMR using inductive heating

We report a simple, efficient method for carrying out nuclear magnetic resonance (NMR) experiments at high temperature in any NMR probe without modification. The sample tube is coated with a thin film of metal and the rf coil used for the NMR experiment is used to inductively heat the film, thus heating the sample inside the tube. Using this approach, we have obtained both proton and high-resolution carbon-13 NMR spectra at temperatures as high as 730 K.

A high-resolution carbon-13 nuclear magnetic resonance study of glycinin in deuterium oxide solutions

Application de la spectroscopie RMN a l'etude de la composition et de la structure de ces proteines du soja. Interpretation des resultats obtenus

High-resolution proton and carbon-13 NMR of membranes: why sonicate?

We have obtained high-field (11.7-T) proton and carbon-13 Fourier transform (FT) nuclear magnetic resonance (NMR) spectra of egg lecithin and egg lecithin-cholesterol (1:1) multibilayers, using "magic-angle" sample spinning (MASS) techniques, and sonicated egg lecithin and egg lecithin-cholesterol (1:1) vesicles, using conventional FT NMR methods. Resolution of the proton and carbon-13 MASS NMR spectra of the pure egg lecithin samples is essentially identical with that of sonicated samples, but spectra of the unsonicated lipid, using MASS, can be obtained very much faster than with the more dilute, sonicated systems. With the 1:1 lecithin-cholesterol systems, proton MASS NMR spectra are virtually identical with conventional FT spectra of sonicated samples, while with 13C NMR, we demonstrate that most 13C nuclei in the cholesterol moiety can be monitored, even though these same nuclei are essentially invisible, i.e., are severely broadened, in the corresponding sonicated systems. In addition, 13C MASS NMR, spectra can again be recorded much faster than with sonicated samples, due to concentration effects. Taken together, these results strongly suggest there will seldom be need in the future to resort to ultrasonic disruption of lipid bilayer membranes in order to obtain high-resolution proton or carbon-13 NMR spectra.

High-resolution carbon-13 nuclear magnetic resonance studies of maize proteins

The first high-field, high-resolution 13 C nuclear magnetic resonance spectra of zein, and two sub-fractions obtained by extraction in aqueous alcohol systems, are reported. Solubility of zein was also investigated in fourteen different organic solvents and found to be optimal in 100% DMSO and 50% pyridine-water. The effects of extraction or pretreatment of zein with specific solvents were also investigated. Spectral assignments are proposed for zein based on a comparison of the 13 C chemical shift values for peaks in the zein spectra with previously published 13 C chemical shift assignments for proteins. Biochemical characterization of the protein samples by SDS-PAGE and amino acid analysis were carried out in parallel with the NMR studies to aid in the interpretation of NMR spectra.

Studying enzyme mechanism by 13C nuclear magnetic resonance.

High-resolution carbon-13 nuclear magnetic resonance (NMR) spectra of enzyme-inhibitor and enzyme-substrate complexes provide detailed structural and stereochemical information on the mechanism of enzyme action. The proteases trypsin and papain are shown to form tetrahedrally coordinated complexes and acyl derivatives with a variety of compounds artificially enriched at the site or sites of interest. These results are compared with the structural information derived from x-ray diffraction. Detailed NMR studies have provided a clearer picture of the ionization state of the residues participating in enzyme-catalyzed processes than other more classical techniques. The dynamics of enzymic catalysis can be observed at sub-zero temperatures by a combination of cryoenzymology and carbon-13 NMR spectroscopy. With these powerful techniques, transient, covalently bound intermediates in enzyme-catalyzed reactions can be detected and their structures rigorously assigned.

High-resolution carbon-13 nuclear magnetic resonance spectrometry and relaxation behavior of organic solids from fossil fuels

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTHigh-resolution carbon-13 nuclear magnetic resonance spectrometry and relaxation behavior of organic solids from fossil fuelsMichael A. Wilson, Anthony M. Vassallo, Philip J. Collin, and Horst. RottendorfCite this: Anal. Chem. 1984, 56, 3, 433–436Publication Date (Print):March 1, 1984Publication History Published online1 May 2002Published inissue 1 March 1984https://doi.org/10.1021/ac00267a031RIGHTS & PERMISSIONSArticle Views57Altmetric-Citations31LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (524 KB) Get e-Alerts Get e-Alerts

ChemInform Abstract: HIGH‐RESOLUTION CARBON‐13 NUCLEAR MAGNETIC RESONANCE SPECTRA OF SOME SOLID ANTHRAQUINONE DYES AND RELATED SPECIES

Chemischer InformationsdienstVolume 14, Issue 51 Physical Organic Chemistry ChemInform Abstract: HIGH-RESOLUTION CARBON-13 NUCLEAR MAGNETIC RESONANCE SPECTRA OF SOME SOLID ANTHRAQUINONE DYES AND RELATED SPECIES A. M. CHIPPENDALE, A. M. CHIPPENDALESearch for more papers by this authorA. MATHIAS, A. MATHIASSearch for more papers by this authorR. S. AUJLA, R. S. AUJLASearch for more papers by this authorR. K. HARRIS, R. K. HARRISSearch for more papers by this authorK. J. PACKER, K. J. PACKERSearch for more papers by this authorB. J. SAY, B. J. SAYSearch for more papers by this author A. M. CHIPPENDALE, A. M. CHIPPENDALESearch for more papers by this authorA. MATHIAS, A. MATHIASSearch for more papers by this authorR. S. AUJLA, R. S. AUJLASearch for more papers by this authorR. K. HARRIS, R. K. HARRISSearch for more papers by this authorK. J. PACKER, K. J. PACKERSearch for more papers by this authorB. J. SAY, B. J. SAYSearch for more papers by this author First published: December 20, 1983 https://doi.org/10.1002/chin.198351043AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article. Volume14, Issue51December 20, 1983 RelatedInformation

Applications of High-Resolution Carbon-13 Nuclear Magnetic Resonance Spectroscopy to Solid Polymers

Systematic research concerning synthetic polymers requires an understanding of molecular-level influences on macroscopic behavior. Chemical structure, morphology, orientation, and chain dynamics, which are known to have important effects on bulk material properties, have all been characterized by various forms of molecular spectroscopy. Despite such efforts, we do not have a complete understanding of the relationship between macroscopic and microscopic properties. Two general problems remain: (1) the requirement of special sample preparation for many types of spectroscopy; and (2) the limited scope of common spectroscopic techniques. Differences in sample preparation, variations in sensitivity, and ambiguities in interpretation combine to complicate the study. Recently developed NMR techniques for high-resolution in solids have demonstrated the potential to solve such problems in many cases. This review focuses on the high-resolution NMR techniques developed for 13C, the nucleus of most general interest for organic polymers. The experimental procedures are explained briefly and the provision of new information in various areas of polymer science by 13C NMR solids is discussed. Specific examples are used and some indication of future potential is presented.

High-resolution carbon-13 nuclear magnetic resonance study of conjugation in solid polyimides

High-resolution carbon-13 nuclear magnetic resonance study of conjugation in solid polyimides

Observations by high-resolution carbon-13 nuclear magnetic resonance of cellulose I related to morphology and crystal structure

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTObservations by high-resolution carbon-13 nuclear magnetic resonance of cellulose I related to morphology and crystal structureWilliam L. Earl and D. L. VanderHartCite this: Macromolecules 1981, 14, 3, 570–574Publication Date (Print):May 1, 1981Publication History Published online1 May 2002Published inissue 1 May 1981https://doi.org/10.1021/ma50004a023RIGHTS & PERMISSIONSArticle Views451Altmetric-Citations168LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (733 KB) Get e-Alerts Get e-Alerts

High-Resolution Carbon-13 Nuclear Magnetic Resonance Studies of Polymers in the Solid State. Aromatic Polyesters

High-Resolution Carbon-13 Nuclear Magnetic Resonance Studies of Polymers in the Solid State. Aromatic Polyesters

High-Resolution Carbon-13 Nuclear Magnetic Resonance Spectra of Solid D-Camphor

Abstract Proton decoupled natural abundance carbon-13 nmr spectra of solid polycrystalline d-camphor have been measured between 275K and 343K. The observed line widths are relatively sharp, making it possible to measure 13C chemical shifts and spin-lattice relaxation times, T1's, for several of the individual carbon resonances. From the temperature dependence of T1 an activation energy of 14.2 ± 2 kJ mole−1 is calculated. Effective rotational correlation times derived from the 13C T1'S are compared with those obtained for d-camphor using dielectric techniques. Some general advantages of proton decoupled 13C nmr over 1H nmr in studying molecular reorientation in orientationally disordered solids are discussed.

High-resolution carbon-13 nuclear magnetic resonance spectra and substituent effects for monohalobenzenes

High-resolution carbon-13 nuclear magnetic resonance spectra and substituent effects for monohalobenzenes