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Sample records for 1h nmr spectroscopy

  1. 1H NMR spectroscopy-based interventional metabolic phenotyping

    Lauridsen, Michael B; Bliddal, Henning; Christensen, Robin;

    2010-01-01

    1H NMR spectroscopy-based metabolic phenotyping was used to identify biomarkers in the plasma of patients with rheumatoid arthritis (RA). Forty-seven patients with RA (23 with active disease at baseline and 24 in remission) and 51 healthy subjects were evaluated during a one-year follow-up with...

  2. Localized double-quantum-filtered 1H NMR spectroscopy

    Thomas, M. A.; Hetherington, H. P.; Meyerhoff, D. J.; Twieg, D. B.

    The image-guided in vivo spectroscopic (ISIS) pulse sequence has been combined with a double-quantum-filter scheme in order to obtain localized and water-suppressed 1H NMR spectra of J-coupled metabolites. The coherence-transfer efficiency associated with the DQ filter for AX and A 3X spin systems is described. Phantom results of carnosine, alanine, and ethanol in aqueous solution are presented. For comparison, the 1H NMR spectrum of alanine in aqueous solution with the binomial (1331, 2662) spin-echo sequence is also shown.

  3. Metabolite Characterization in Peritoneal Dialysis Effluent Using High-resolution 1H and 1H-13C NMR Spectroscopy

    Guleria, Anupam; Rawat, Atul; Khetrapal, C L; Prasad, Narayan; Kumar, Dinesh

    2014-01-01

    Metabolite analysis of peritoneal dialysis (PD) effluent may provide information regarding onset and progression of complications associated with prolonged PD therapy. In this context, the NMR detectable small metabolites of PD effluent samples were characterized using high resolution 1H and 1H-13C NMR spectroscopy. The various spectra were recorded (at 800 MHz proton frequency) on PD effluent samples obtained after 4 hour (intraperitoneal) dwell time from patients with end stage renal failure (ESRF) and continuing normally on PD therapy. Inspite of devastating spectral feature of PD effluent due to the presence of intense resonances from glucose and lactate, we were able to identify about 53 small endogenous metabolites (including many complex coupled spin systems) and more than 90 % of the total CH cross peaks of 1H-13C HSQC spectrum were identified specific to various metabolites of PD effluent. We foresee that the characteristic fingerprints of various metabolites of control PD effluent samples will be us...

  4. Structural analysis of the carbohydrate chains of glycoproteins by 500-MHz 1H-NMR spectroscopy

    This thesis deals with the structural analysis by 500-MHz 1H-NMR spectroscopy of carbohydrate chains obtained from glycoproteins. In the chapters 1 to 6 the structural analysis of N-glycosidically linked carbohydrate chains is described. The chapters 7 to 10 describe the structural analysis of O-glycosidically linked carbohydrate chains. 381 refs.; 44 figs.; 24 tabs.; 7 schemes

  5. Suppression of baseline artifacts in 1H NMR spectroscopy of diluted water solutions

    Suppression of baseline artifacts in 1H NMR spectroscopy of diluted aqueous solutions has been discussed. The time-domain technique capable of eliminating or lowering the baseline distortions in the spectra caused by the ringing of low pas filters has been proposed. Simultaneously, the problem of proper adjusting of the start of data acquisition have been discussed

  6. Statistical contributrion to the analysis of metabonomic data in 1H-NMR spectroscopy

    Rousseau, Réjane

    2011-01-01

    This thesis provides a complete methodology to lead a metabonomic study from the data acquisition to the discovery of biomarkers. Metabonomics aims to discover biomarkers or the metabolites altered in biological reactions. 1H-NMR spectroscopy is used to generate spectral profiles describing the composition of metabolites in collected biofluid samples. Statistical comparisons of spectra obtained in various biological states permits a quantitative investigation of metabolites changes inherent t...

  7. Metabolic phenotyping by 1H-NMR spectroscopy detects lung cancer via a simple blood sample

    Louis,Evelyne; MESOTTEN, Liesbet; Thomeer, Michiel; Vandeurzen, Kurt; Darquennes, Karen; Vanhove, Karolien; Reekmans, Gunter; Adriaensens, Peter

    2013-01-01

    Introduction: Lung cancer is the leading cause of cancer death worldwide. There is an urgent need of effective methods to detect lung cancer. Accumulating evidence shows that the metabolism of cancer cells differs from that of normal cells. Disturbances in biochemical pathways which occur during the development of cancer provoke changes in the metabolic phenotype. Objective: To determine the metabolic phenotype of lung cancer by 1H-NMR spectroscopy. Methods: Fasting venous blood samples of 78...

  8. 1H to 13C Energy Transfer in Solid State NMR Spectroscopy of Natural Organic Systems

    Berns, Anne E.; Conte, Pellegrino

    2010-05-01

    Cross polarization (CP) magic angle spinning (MAS) 13C-NMR spectroscopy is a solid state NMR technique widely used to study chemical composition of organic materials with low or no solubility in the common deuterated solvents used to run liquid state NMR experiments. Based on the magnetization transfer from abundant nuclei (with spin of 1 -2) having a high gyromagnetic ratio (γ), such as protons, to the less abundant 13C nuclei with low γ values, 13C-CPMAS NMR spectroscopy is often applied in environmental chemistry to obtain quantitative information on the chemical composition of natural organic matter (NOM) (Conte et al., 2004), although its quantitative assessment is still matter of heavy debates. Many authors (Baldock et al., 1997; Conte et al., 1997, 2002; Dria et al., 2002; Kiem et al., 2000; Kögel-Knabner, 2000; Preston, 2001), reported that the application of appropriate instrument setup as well as the use of special pulse sequences and correct spectra elaboration may provide signal intensities that are directly proportional to the amount of nuclei creating a NMR signal. However, many other papers dealt with the quantitative unsuitability of 13C-CPMAS NMR spectroscopy. Among those, Mao et al. (2000), Smernik and Oades (2000 a,b), and Preston (2001) reported that cross-polarized NMR techniques may fail in a complete excitation of the 13C nuclei. In fact, the amount of observable carbons via 13C-CPMAS NMR spectroscopy appeared, in many cases, lower than that measured by a direct observation of the 13C nuclei. As a consequence, cross-polarized NMR techniques may provide spectra where signal distribution may not be representative of the quantitative distribution of the different natural organic matter components. Cross-polarization is obtained after application of an initial 90° x pulse on protons and a further spin lock pulse (along the y axis) having a fixed length (contact time) for both nuclei (1H and 13C) once the Hartmann-Hahn condition is matched

  9. Classification of Wines Based on Combination of 1H NMR Spectroscopy and Principal Component Analysis

    DU, Yuan-Yuan; BAI, Guo-Yun; ZHANG, Xu; LIU, Mai-Li

    2007-01-01

    A combination of 1H nuclear magnetic resonance (NMR) spectroscopy and principal component analysis (PCA)has shown the potential for being a useful method for classification of type, production origin or geographic origin of wines. In this preliminary study, twenty-one bottled wines were classified/separated for their location of production in Shacheng, Changli and Yantai, and the types of the blended, medium dry, dry white and dry red wines, using the NMR-PCA method. The wines were produced by three subsidiary companies of an enterprise according to the same national standard. The separation was believed to be mainly due to the fermentation process for different wines and environmental variations, such as local climate, soil, underground water, sunlight and rainfall. The major chemicals associated with the separation were identified.

  10. Authentication of beef versus horse meat using 60 MHz 1H NMR spectroscopy.

    Jakes, W; Gerdova, A; Defernez, M; Watson, A D; McCallum, C; Limer, E; Colquhoun, I J; Williamson, D C; Kemsley, E K

    2015-05-15

    This work reports a candidate screening protocol to distinguish beef from horse meat based upon comparison of triglyceride signatures obtained by 60 MHz (1)H NMR spectroscopy. Using a simple chloroform-based extraction, we obtained classic low-field triglyceride spectra from typically a 10 min acquisition time. Peak integration was sufficient to differentiate samples of fresh beef (76 extractions) and horse (62 extractions) using Naïve Bayes classification. Principal component analysis gave a two-dimensional "authentic" beef region (p=0.001) against which further spectra could be compared. This model was challenged using a subset of 23 freeze-thawed training samples. The outcomes indicated that storing samples by freezing does not adversely affect the analysis. Of a further collection of extractions from previously unseen samples, 90/91 beef spectra were classified as authentic, and 16/16 horse spectra as non-authentic. We conclude that 60 MHz (1)H NMR represents a feasible high-throughput approach for screening raw meat. PMID:25577043

  11. (1)H NMR Spectroscopy of Fecal Extracts Enables Detection of Advanced Colorectal Neoplasia.

    Amiot, Aurelien; Dona, Anthony C; Wijeyesekera, Anisha; Tournigand, Christophe; Baumgaertner, Isabelle; Lebaleur, Yann; Sobhani, Iradj; Holmes, Elaine

    2015-09-01

    Colorectal cancer (CRC) is a growing cause of mortality in developing countries, warranting investigation into its etiopathogenesis and earlier diagnosis. Here, we investigated the fecal metabolic phenotype of patients with advanced colorectal neoplasia and controls using (1)H-nuclear magnetic resonance (NMR) spectroscopy and multivariate modeling. The fecal microbiota composition was assessed by quantitative real-time PCR as well as Wif-1 methylation levels in stools, serum, and urine and correlated to the metabolic profile of each patient. The predictivity of the model was 0.507 (Q(2)Y), and the explained variance was 0.755 (R(2)Y). Patients with advanced colorectal neoplasia demonstrated increased fecal concentrations of four short-chain fatty acids (valerate, acetate, propionate, and butyrate) and decreased signals relating to β-glucose, glutamine, and glutamate. The predictive accuracy of the multivariate (1)H NMR model was higher than that of the guaiac-fecal occult blood test and the Wif-1 methylation test for predicting advanced colorectal neoplasia. Correlation analysis between fecal metabolites and bacterial profiles revealed strong associations between Faecalibacterium prausnitzii and Clostridium leptum species with short-chain fatty acids concentration and inverse correlation between Faecalibacterium prausnitzii and glucose. These preliminary results suggest that fecal metabonomics may potentially have a future role in a noninvasive colorectal screening program and may contribute to our understanding of the role of these dysregulated molecules in the cross-talk between the host and its bacterial microbiota. PMID:26211820

  12. Low-field (1)H NMR spectroscopy for distinguishing between arabica and robusta ground roast coffees.

    Defernez, Marianne; Wren, Ella; Watson, Andrew D; Gunning, Yvonne; Colquhoun, Ian J; Le Gall, Gwénaëlle; Williamson, David; Kemsley, E Kate

    2017-02-01

    This work reports a new screening protocol for addressing issues of coffee authenticity using low-field (60MHz) bench-top (1)H NMR spectroscopy. Using a simple chloroform-based extraction, useful spectra were obtained from the lipophilic fraction of ground roast coffees. It was found that 16-O-methylcafestol (16-OMC, a recognized marker compound for robusta beans) gives rise to an isolated peak in the 60MHz spectrum, which can be used as an indicator of the presence of robusta beans in the sample. A total of 81 extracts from authenticated coffees and mixtures were analysed, from which the detection limit of robusta in arabica was estimated to be between 10% and 20% w/w. Using the established protocol, a surveillance exercise was conducted of 27 retail samples of ground roast coffees which were labelled as "100% arabica". None were found to contain undeclared robusta content above the estimated detection limit. PMID:27596398

  13. Discovering [superscript 13]C NMR, [superscript 1]H NMR, and IR Spectroscopy in the General Chemistry Laboratory through a Sequence of Guided-Inquiry Exercises

    Iler, H. Darrell; Justice, David; Brauer, Shari; Landis, Amanda

    2012-01-01

    This sequence of three guided-inquiry labs is designed for a second-semester general chemistry course and challenges students to discover basic theoretical principles associated with [superscript 13]C NMR, [superscript 1]H NMR, and IR spectroscopy. Students learn to identify and explain basic concepts of magnetic resonance and vibrational…

  14. High sensitivity 1H-NMR spectroscopy of homeopathic remedies made in water

    Anick David J

    2004-11-01

    Full Text Available Abstract Background The efficacy of homeopathy is controversial. Homeopathic remedies are made via iterated shaking and dilution, in ethanol or in water, from a starting substance. Remedies of potency 12 C or higher are ultra-dilute (UD, i.e. contain zero molecules of the starting material. Various hypotheses have been advanced to explain how a UD remedy might be different from unprepared solvent. One such hypothesis posits that a remedy contains stable clusters, i.e. localized regions where one or more hydrogen bonds remain fixed on a long time scale. High sensitivity proton nuclear magnetic resonance spectroscopy has not previously been used to look for evidence of differences between UD remedies and controls. Methods Homeopathic remedies made in water were studied via high sensitivity proton nuclear magnetic resonance spectroscopy. A total of 57 remedy samples representing six starting materials and spanning a variety of potencies from 6 C to 10 M were tested along with 46 controls. Results By presaturating on the water peak, signals could be reliably detected that represented H-containing species at concentrations as low as 5 μM. There were 35 positions where a discrete signal was seen in one or more of the 103 spectra, which should theoretically have been absent from the spectrum of pure water. Of these 35, fifteen were identified as machine-generated artifacts, eight were identified as trace levels of organic contaminants, and twelve were unexplained. Of the unexplained signals, six were seen in just one spectrum each. None of the artifacts or unexplained signals occurred more frequently in remedies than in controls, using a p Conclusion No discrete signals suggesting a difference between remedies and controls were seen, via high sensitivity 1H-NMR spectroscopy. The results failed to support a hypothesis that remedies made in water contain long-lived non-dynamic alterations of the H-bonding pattern of the solvent.

  15. Scalable synthesis of quaterrylene: solution-phase 1H NMR spectroscopy of its oxidative dication.

    Thamatam, Rajesh; Skraba, Sarah L; Johnson, Richard P

    2013-10-14

    Quaterrylene is prepared in a single reaction and high yield by Scholl-type coupling of perylene, utilizing trifluoromethanesulfonic acid as catalyst and DDQ or molecular oxygen as oxidant. Dissolution in 1 M triflic acid/dichloroethane with sonication yields the aromatic quaterrylene oxidative dication, which is characterized by its (1)H NMR spectrum. PMID:23999880

  16. 1H NMR Spectroscopy and MVA Analysis of Diplodus sargus Eating the Exotic Pest Caulerpa cylindracea

    Sandra A. De Pascali

    2015-06-01

    Full Text Available The green alga Caulerpa cylindracea is a non-autochthonous and invasive species that is severely affecting the native communities in the Mediterranean Sea. Recent researches show that the native edible fish Diplodus sargus actively feeds on this alga and cellular and physiological alterations have been related to the novel alimentary habits. The complex effects of such a trophic exposure to the invasive pest are still poorly understood. Here we report on the metabolic profiles of plasma from D. sargus individuals exposed to C. cylindracea along the southern Italian coast, using 1H NMR spectroscopy and multivariate analysis (Principal Component Analysis, PCA, Orthogonal Partial Least Square, PLS, and Orthogonal Partial Least Square Discriminant Analysis, OPLS-DA. Fish were sampled in two seasonal periods from three different locations, each characterized by a different degree of algal abundance. The levels of the algal bisindole alkaloid caulerpin, which is accumulated in the fish tissues, was used as an indicator of the trophic exposure to the seaweed and related to the plasma metabolic profiles. The profiles appeared clearly influenced by the sampling period beside the content of caulerpin, while the analyses also supported a moderate alteration of lipid and choline metabolism related to the Caulerpa-based diet.

  17. Metabonomic signature analysis of cervical carcinoma and precancerous lesions in women by 1H NMR spectroscopy

    Hasim, Ayshamgul; ALI, MAYINUER; MAMTIMIN, BATUR; Ma, Jun-Qi; Li, Qiao-Zhi; ABUDULA, ABULIZI

    2012-01-01

    1H nuclear magnetic resonance (NMR)-based metabonomics has been used to characterize the metabolic profiles of cervical intraepithelial neoplasia (CIN) and cervical squamous cell carcinoma (CSCC). Principal component analysis (PCA) and orthogonal partial least-squares discriminant analysis (OPLS-DA) were used to model the systematic variation related to patients with CIN or CSCC with healthy controls. Potential metabolic biomarkers were identified using database comparisons, and the one-way a...

  18. Impact of Adenovirus infection in host cell metabolism evaluated by (1)H-NMR spectroscopy.

    Silva, Ana Carina; P Teixeira, Ana; M Alves, Paula

    2016-08-10

    Adenovirus-based vectors are powerful vehicles for gene transfer applications in vaccination and gene therapy. Although highly exploited in the clinical setting, key aspects of the adenovirus biology are still not well understood, in particular the subversion of host cell metabolism during viral infection and replication. The aim of this work was to gain insights on the metabolism of two human cell lines (HEK293 and an amniocyte-derived cell line, 1G3) after infection with an adenovirus serotype 5 vector (AdV5). In order to profile metabolic alterations, we used (1)H-NMR spectroscopy, which allowed the quantification of 35 metabolites in cell culture supernatants with low sample preparation and in a relatively short time. Significant differences between both cell lines in non-infected cultures were identified, namely in glutamine and acetate metabolism, as well as by-product secretion. The main response to AdV5 infection was an increase in glucose consumption and lactate production rates. Moreover, cultures performed with or without glutamine supplementation confirmed the exhaustion of this amino acid as one of the main causes of lower AdV5 production at high cell densities (10- and 1.5-fold less specific yields in HEK293 and 1G3 cells, respectively), and highlighted different degrees of glutamine dependency of adenovirus replication in each cell line. The observed metabolic alterations associated with AdV5 infection and specificity of the host cell line can be useful for targeted bioprocess optimization. PMID:27215342

  19. Strategies for organic impurity quantification by 1H NMR spectroscopy: Constrained total-line-shape fitting

    A constrained total-line-shape (CTLS) fitting strategy for organic impurity analysis from 1H NMR spectra was developed and assessed by studying two examples. In general, total-line-shape fitting allows integration of overlapping lines without suffering from baseline artifacts as much as traditional integration methods. It is shown here that the constrained total-line-shape fitting, where the spectral structures of the multiplets to be fitted are taken into account in form of constraints, allows quantification of seriously overlapping lines and when the signals are close to the root of major signals. Also, a method for removal of 13C satellite signals is described. The results indicate that our approach significantly improves the usefulness of qNMR in impurity analysis and that impurity levels of 0.1 mol%, which in some cases means down to 0.01 wt%, can be easily determined with relative standard error smaller than 10%

  20. Metabolic phenotyping by 1H-NMR spectroscopy to detect lung cancer via a simple blood sample

    Louis,Evelyne; Adriaensens, Peter; MESOTTEN, Liesbet; Thomeer, Michiel; Reekmans, Gunter; Vanhove, Karolien; Vandeurzen, Kurt; Darquennes, Karen

    2013-01-01

    Introduction: Lung cancer is the leading cause of cancer death worldwide. There is an urgent need of effective methods to detect lung cancer. Accumulating evidence shows that the metabolism of cancer cells differs from that of normal cells. Disturbances in biochemical pathways which occur during the development of cancer provoke changes in the metabolic phenotype. Objective: To determine the metabolic phenotype of lung cancer by 1H-NMR spectroscopy. Methods: Fasting venous blood samples of 78...

  1. In vivo NMR field-cycling relaxation spectroscopy reveals 14N1H relaxation sinks in the backbones of proteins

    In this preliminary note, the authors report an in vivo study of Hirudo medicinalis, using field-cycling relaxation spectroscopy, showing clear 14N1H quadrupole dips, proving that the amide 14N1H groups of proteins can act as relaxation sinks in a frequency range relevant for NMR tomography. Also, as a byproduct of this work it is noted that during these experiments, leeches were exposed to field variation rates of about 50 Ts-1 in several thousand field-cycles up and down, without any obvious damage. (U.K.)

  2. Metabolic profiling studies on the toxicological effects of realgar in rats by 1H NMR spectroscopy

    The toxicological effects of realgar after intragastrical administration (1 g/kg body weight) were investigated over a 21 day period in male Wistar rats using metabonomic analysis of 1H NMR spectra of urine, serum and liver tissue aqueous extracts. Liver and kidney histopathology examination and serum clinical chemistry analyses were also performed. 1H NMR spectra and pattern recognition analyses from realgar treated animals showed increased excretion of urinary Kreb's cycle intermediates, increased levels of ketone bodies in urine and serum, and decreased levels of hepatic glucose and glycogen, as well as hypoglycemia and hyperlipoidemia, suggesting the perturbation of energy metabolism. Elevated levels of choline containing metabolites and betaine in serum and liver tissue aqueous extracts and increased serum creatine indicated altered transmethylation. Decreased urinary levels of trimethylamine-N-oxide, phenylacetylglycine and hippurate suggested the effects on the gut microflora environment by realgar. Signs of impairment of amino acid metabolism were supported by increased hepatic glutamate levels, increased methionine and decreased alanine levels in serum, and hypertaurinuria. The observed increase in glutathione in liver tissue aqueous extracts could be a biomarker of realgar induced oxidative injury. Serum clinical chemistry analyses showed increased levels of lactate dehydrogenase, aspartate aminotransferase, and alkaline phosphatase as well as increased levels of blood urea nitrogen and creatinine, indicating slight liver and kidney injury. The time-dependent biochemical variations induced by realgar were achieved using pattern recognition methods. This work illustrated the high reliability of NMR-based metabonomic approach on the study of the biochemical effects induced by traditional Chinese medicine

  3. The secondary structure of echistatin from 1H-NMR, circular-dichroism and Raman spectroscopy.

    Saudek, V; Atkinson, R A; Lepage, P; Pelton, J T

    1991-12-01

    Detailed biophysical studies have been carried out on echistatin, a member of the disintegrin family of small, cysteine-rich, RGD-containing proteins, isolated from the venom of the saw-scaled viper Echis carinatus. Analysis of circular-dichroism spectra indicates that, at 20 degrees C, echistatin contains no alpha-helix but contains mostly beta-turns and beta-sheet. Two isobestic points are observed as the temperature is raised, the conformational changes associated with that observed between 40 degrees C and 72 degrees C being irreversible. Raman spectra also indicate considerable beta-turn and beta-sheet (20%) structure and an absence of alpha-helical structure. Three of the four disulphide bridges are shown to be in an all-gauche conformation, while the fourth adopts a trans-gauche-gauche conformation. The 1H-NMR spectrum of echistatin has been almost fully assigned. A single conformation was observed at 27 degrees C with the four proline residues adopting only the trans conformation. A large number of backbone amide protons were found to exchange slowly, but no segments of the backbone were found to be in either alpha-helical or beta-sheet conformation. A number of turns could be characterised. An irregular beta-hairpin contains the RGD sequence in a mobile loop at its tip. Two of the four disulphide cross-links have been identified from the NMR spectra. The data presented in this paper will serve to define the structure of echistatin more closely in subsequent studies. PMID:1761037

  4. In vivo1H NMR spectroscopy of the human brain at 9.4 T: Initial results

    Deelchand, Dinesh Kumar; Moortele, Pierre-François Van de; Adriany, Gregor; Iltis, Isabelle; Andersen, Peter; Strupp, John P.; Thomas Vaughan, J.; Uğurbil, Kâmil; Henry, Pierre-Gilles

    2010-09-01

    In vivo proton NMR spectroscopy allows non-invasive detection and quantification of a wide range of biochemical compounds in the brain. Higher field strength is generally considered advantageous for spectroscopy due to increased signal-to-noise and increased spectral dispersion. So far 1H NMR spectra have been reported in the human brain up to 7 T. In this study we show that excellent quality short echo time STEAM and LASER 1H NMR spectra can be measured in the human brain at 9.4 T. The information content of the human brain spectra appears very similar to that measured in the past decade in rodent brains at the same field strength, in spite of broader linewidth in human brain. Compared to lower fields, the T1 relaxation times of metabolites were slightly longer while T2 relaxation values of metabolites were shorter (<100 ms) at 9.4 T. The linewidth of the total creatine (tCr) resonance at 3.03 ppm increased linearly with magnetic field (1.35 Hz/T from 1.5 T to 9.4 T), with a minimum achievable tCr linewidth of around 12.5 Hz at 9.4 T. At very high field, B0 microsusceptibility effects are the main contributor to the minimum achievable linewidth.

  5. Selective excitation enables assignment of proton resonances and {sup 1}H-{sup 1}H distance measurement in ultrafast magic angle spinning solid state NMR spectroscopy

    Zhang, Rongchun; Ramamoorthy, Ayyalusamy, E-mail: ramamoor@umich.edu [Biophysics and Department of Chemistry, The University of Michigan, Ann Arbor, Michigan 48109-1055 (United States)

    2015-07-21

    Remarkable developments in ultrafast magic angle spinning (MAS) solid-state NMR spectroscopy enabled proton-based high-resolution multidimensional experiments on solids. To fully utilize the benefits rendered by proton-based ultrafast MAS experiments, assignment of {sup 1}H resonances becomes absolutely necessary. Herein, we propose an approach to identify different proton peaks by using dipolar-coupled heteronuclei such as {sup 13}C or {sup 15}N. In this method, after the initial preparation of proton magnetization and cross-polarization to {sup 13}C nuclei, transverse magnetization of desired {sup 13}C nuclei is selectively prepared by using DANTE (Delays Alternating with Nutations for Tailored Excitation) sequence and then, it is transferred to bonded protons with a short-contact-time cross polarization. Our experimental results demonstrate that protons bonded to specific {sup 13}C atoms can be identified and overlapping proton peaks can also be assigned. In contrast to the regular 2D HETCOR experiment, only a few 1D experiments are required for the complete assignment of peaks in the proton spectrum. Furthermore, the finite-pulse radio frequency driven recoupling sequence could be incorporated right after the selection of specific proton signals to monitor the intensity buildup for other proton signals. This enables the extraction of {sup 1}H-{sup 1}H distances between different pairs of protons. Therefore, we believe that the proposed method will greatly aid in fast assignment of peaks in proton spectra and will be useful in the development of proton-based multi-dimensional solid-state NMR experiments to study atomic-level resolution structure and dynamics of solids.

  6. Chemically Methylated and Reduced Pectins: Preparation and Characterisation by 1H-NMR Spectroscopy, Enzymatic Degradation and Gelling Properties

    Rosenbohm, Christoph; Lundt, Inge; Christensen, T.M.I.E.; Young, N.W.G.

    2003-01-01

    The gelling properties of pectin are known to be closely related to the degree of methylation (DM) and the distribution of the ester groups. In order to investigate this dependency, a natural citrus pectin (DM=64%) has been methylated to pectins with higher DM’s or saponified to achieve pectins w...... activities than with unmodified pectin. The new reduced pectins exhibit high gelling properties. Keywords: Pectin; Methylation; Deesterification; Reduction; DM and DR by 1H-NMR spectroscopy; Reduced Pectin; Pectinases; Gelling properties....

  7. Metabonomic signature analysis of cervical carcinoma and precancerous lesions in women by (1)H NMR spectroscopy.

    Hasim, Ayshamgul; Ali, Mayinuer; Mamtimin, Batur; Ma, Jun-Qi; Li, Qiao-Zhi; Abudula, Abulizi

    2012-06-01

    (1)H nuclear magnetic resonance (NMR)-based metabonomics has been used to characterize the metabolic profiles of cervical intraepithelial neoplasia (CIN) and cervical squamous cell carcinoma (CSCC). Principal component analysis (PCA) and orthogonal partial least-squares discriminant analysis (OPLS-DA) were used to model the systematic variation related to patients with CIN or CSCC with healthy controls. Potential metabolic biomarkers were identified using database comparisons, and the one-way analysis of variance (ANOVA) test was used to examine the significance of the metabolites. Compared with plasma obtained from the healthy controls, plasma from patients with CIN had higher levels of very-low density lipoprotein (VLDL), acetone, unsaturated lipid and carnitine, together with lower levels of creatine, lactate, isoleucine, leucine, valine, alanine, glutamine, histidine, glycine, acetylcysteine, myo-inositol, choline and glycoprotein. Plasma from patients with CSCC had higher levels of acetate and formate, together with lower levels of creatine, lactate, isoleucine, leucine, valine, alanine, glutamine, histidine and tyrosine compared with the plasma of the healthy controls. In addition, compared with the plasma of patients with CIN, the plasma of CSCC patients had higher levels of acetate, formate, lactate, isoleucine, leucine, valine, alanine, glutamine, histidine, tyrosine, acetylcysteine, myo-inositol, glycoprotein, α-glucose and β-glucose, together with lower levels of acetone, unsaturated lipid and carnitine. Moreover, the profiles showed high feasibility and specificity by statistical analysis with OPLS-DA compared to the Thinprep cytology test (TCT) by setting the histopathological outcome as standard. The metabolic profile obtained for cervical cancer is significant, even for the precancerous disease. This suggests a systemic metabolic response to cancer, which may be used to identify potential early diagnostic biomarkers of the cancer and to establish

  8. Effect of 1,10-phenanthroline aromaticity in carboxylic acids:1H NMR spectroscopy, GIAO calculations and thermodynamic properties

    Machado, Camila M. B.; Santos, Vanessa F. C.; Belarmino, Marcia K. D. L.; França, José A. A.; Moura, Gustavo L. C.; Lima, Nathalia B. D.

    2016-08-01

    Hydrogen bonding represents a class of chemical interactions, which are directly responsible for several physical properties, such as: energetic stabilities, boiling points, vibrational modes, bond lengths, etc. In this article, we examine from the point of view of 1H NMR spectroscopy and GIAO calculations, the effects associated with the process of formation of the hydrogen bonds as they appear in the chemical shifts of the acidic hydrogens in the complexes between nitrogenated compounds, PHEN, BIPY and DIBIPY, and carboxylic acids, HOOCH, HOOCCH3 and HOOCC6H5. All computational simulations were performed using the quantum chemical methods B3LYP/6-31++G(d,p) and ωB97X-D/def2-TZVP. The 1H NMR spectroscopy results showed that, in both cases, the hydrogen nucleus of the OH group is the most affected in the process of hydrogen bond formation. For the complexes involving PHEN we observed that the hydrogen nucleus is more strongly shielded when compared with this signal in the corresponding complexes involving BIPY and DIBIPY.

  9. Experimental and analytical variation in human urine in 1H NMR spectroscopy-based metabolic phenotyping studies.

    Maher, Anthony D; Zirah, Séverine F M; Holmes, Elaine; Nicholson, Jeremy K

    2007-07-15

    1H NMR spectroscopy potentially provides a robust approach for high-throughput metabolic screening of biofluids such as urine and plasma, but sample handling and preparation need careful optimization to ensure that spectra accurately report biological status or disease state. We have investigated the effects of storage temperature and time on the 1H NMR spectral profiles of human urine from two participants, collected three times a day on four different days. These were analyzed using modern chemometric methods. Analytical and preparation variation (tested between -40 degrees C and room temperature) and time of storage (to 24 h) were found to be much less influential than biological variation in sample classification. Statistical total correlation spectroscopy and discriminant function methods were used to identify the specific metabolites that were hypervariable due to preparation and biology. Significant intraindividual variation in metabolite profiles were observed even for urine collected on the same day and after at least 6 h fasting. The effect of long-term storage at different temperatures was also investigated, showing urine is stable if frozen for at least 3 months and that storage at room temperature for long periods (1-3 months) results in a metabolic profile explained by bacterial activity. Presampling (e.g., previous day) intake of food and medicine can also strongly influence the urinary metabolic profiles indicating that collective detailed participant historical meta data are important for interpretation of metabolic phenotypes and for avoiding false biomarker discovery. PMID:17555297

  10. Formation of κ-carrageenan-gelatin polyelectrolyte complexes studied by (1)H NMR, UV spectroscopy and kinematic viscosity measurements.

    Voron'ko, Nicolay G; Derkach, Svetlana R; Vovk, Mikhail A; Tolstoy, Peter M

    2016-10-20

    The intermolecular interactions between an anionic polysaccharide from the red algae κ-carrageenan and a gelatin polypeptide, forming stoichiometric polysaccharide-polypeptide (bio)polyelectrolyte complexes in the aqueous phase, were examined. The major method of investigation was high-resolution (1)H NMR spectroscopy. Additional data were obtained by UV absorption spectroscopy, light scattering dispersion and capillary viscometry. Experimental data were interpreted in terms of the changing roles of electrostatic interactions, hydrophobic interactions and hydrogen bonds when κ-carrageenan-gelatin complexes are formed. At high temperatures, when biopolymer macromolecules in solution are in the state of random coil, hydrophobic interactions make a major contribution to complex stabilization. At the temperature of gelatin's coil→helix conformational transition and at lower temperatures, electrostatic interactions and hydrogen bonds play a defining role in complex formation. A proposed model of the κ-carrageenan-gelatin complex is discussed. PMID:27474666

  11. LC-MS- and (1)H NMR Spectroscopy-Guided Identification of Antifungal Diterpenoids from Sagittaria latifolia.

    Ravu, Ranga Rao; Jacob, Melissa R; Jeffries, Cynthia; Tu, Ying; Khan, Shabana I; Agarwal, Ameeta K; Guy, R Kiplin; Walker, Larry A; Clark, Alice M; Li, Xing-Cong

    2015-09-25

    Antifungal screening of small-molecule natural product libraries showed that a column fraction (CF) derived from the plant extract of Sagittaria latifolia was active against the fungal pathogen Cryptococcus neoformans. Dereplication analysis by liquid chromatography-mass spectrometry (LC-MS) and proton nuclear magnetic resonance spectroscopy ((1)H NMR) indicated the presence of new compounds in this CF. Subsequent fractionation of the plant extract resulted in the identification of two new isopimaradiene-type diterpenoids, 1 and 2. The structures of 1 and 2 were determined by chemical methods and spectroscopic analysis as isopimara-7,15-dien-19-ol 19-O-α-l-arabinofuranoside and isopimara-7,15-dien-19-ol 19-O-α-l-(5'-acetoxy)arabinofuranoside, respectively. Compound 1 exhibited IC50 values of 3.7 and 1.8 μg/mL, respectively, against C. neoformans and C. gattii. Its aglycone, isopimara-7,15-dien-19-ol (3), resulting from acid hydrolysis of 1, was also active against the two fungal pathogens, with IC50 values of 9.2 and 6.8 μg/mL, respectively. This study demonstrates that utilization of the combined LC-MS and (1)H NMR analytical tools is an improved chemical screening approach for hit prioritization in natural product drug discovery. PMID:26371504

  12. Metabolic Discrimination of Catharanthus roseus Leaves Infected by Phytoplasma Using 1H-NMR Spectroscopy and Multivariate Data Analysis1

    Choi, Young Hae; Tapias, Elisabet Casas; Kim, Hye Kyong; Lefeber, Alfons W.M.; Erkelens, Cornelis; Verhoeven, Jacobus Th.J.; Brzin, Jernej; Zel, Jana; Verpoorte, Robert

    2004-01-01

    A comprehensive metabolomic profiling of Catharanthus roseus L. G. Don infected by 10 types of phytoplasmas was carried out using one-dimensional and two-dimensional NMR spectroscopy followed by principal component analysis (PCA), an unsupervised clustering method requiring no knowledge of the data set and used to reduce the dimensionality of multivariate data while preserving most of the variance within it. With a combination of these techniques, we were able to identify those metabolites that were present in different levels in phytoplasma-infected C. roseus leaves than in healthy ones. The infection by phytoplasma in C. roseus leaves causes an increase of metabolites related to the biosynthetic pathways of phenylpropanoids or terpenoid indole alkaloids: chlorogenic acid, loganic acid, secologanin, and vindoline. Furthermore, higher abundance of Glc, Glu, polyphenols, succinic acid, and Suc were detected in the phytoplasma-infected leaves. The PCA of the 1H-NMR signals of healthy and phytoplasma-infected C. roseus leaves shows that these metabolites are major discriminating factors to characterize the phytoplasma-infected C. roseus leaves from healthy ones. Based on the NMR and PCA analysis, it might be suggested that the biosynthetic pathway of terpenoid indole alkaloids, together with that of phenylpropanoids, is stimulated by the infection of phytoplasma. PMID:15286294

  13. The Discovery-Oriented Approach to Organic Chemistry. 2. Selectivity in Alcohol Oxidation. An Exercise in 1H NMR Spectroscopy for Sophomore Organic Laboratories

    Shadwick, Steven R.; Mohan, Ram S.

    1999-08-01

    We have developed a simple oxidation experiment that presents the student with a puzzle and is a good exercise in 1H NMR spectroscopy. The experiment, which illustrates the important concept of selectivity in organic synthesis, involves selective oxidation of a mixture of 1-heptanol and 2-heptanol using commercial swimming pool chlorine. 1H NMR analysis of the product mixture allows the student to determine the selectivity exhibited by the reagent.

  14. Evaluation of chemical changes during Myrciaria cauliflora (jabuticaba fruit) fermentation by {sup 1}H NMR spectroscopy and chemometric analyses

    Fortes, Gilmara A.C.; Naves, Sara S.; Ferri, Pedro H.; Santos, Suzana C., E-mail: suzana.quimica.ufg@hotmail.com [Universidade Federal de Goias (UFG), Goiania, GO (Brazil). Inst. de Quimica. Lab. de Bioatividade Molecular

    2012-10-15

    Organic acids, sugars, alcohols, phenolic compounds, color properties, pH and titratable acidity were monitored during the commercial fermentation of jabuticaba (Myrciaria cauliflora) by {sup 1}H nuclear magnetic resonance (NMR) spectroscopy, spectrophotometric assays and standard methods of analysis. Data collected was analyzed by principal component (PCA), hierarchical cluster (HCA) and canonical correlation (CCA) analyses. Two sample groups were distinguished and the variables responsible for separation were sugars, anthocyanins, alcohols, hue and acetic and succinic acids. The canonical correlation analysis confirmed the influence of alcohols (ethanol, methanol and glycerol), organic acids (citric, succinic and acetic acids), pH and titratable acidity on the extraction and stability of anthocyanins and co pigments. As a result, color properties were also affected by phenolic variation throughout the fermentative process. (author)

  15. (1)H NMR spectroscopy and chemometrics evaluation of non-thermal processing of orange juice.

    Alves Filho, Elenilson G; Almeida, Francisca D L; Cavalcante, Rosane S; de Brito, Edy S; Cullen, Patrick J; Frias, Jesus M; Bourke, Paula; Fernandes, Fabiano A N; Rodrigues, Sueli

    2016-08-01

    This study evaluated the effect of atmospheric cold plasma and ozone treatments on the key compounds (sugars, amino acids and short chain organic acids) in orange juice by NMR and chemometric analysis. The juice was directly and indirectly exposed to atmospheric cold plasma field at 70kV for different treatment time (15, 30, 45 and 60sec). For ozone processing different loads were evaluated. The Principal Component Analysis shown that the groups of compounds are affected differently depending on the processing. The ozone was the processing that more affected the aromatic compounds and atmospheric cold plasma processing affected more the aliphatic compounds. However, these variations did not result in significant changes in orange juice composition as a whole. Thus, NMR data and chemometrics were suitable to follow quality changes in orange juice processing by atmospheric cold plasma and ozone. PMID:26988481

  16. Metabolic phenotyping of blood plasma by 1H-NMR spectroscopy to detect lung cancer?

    Louis,Evelyne; MESOTTEN, Liesbet; Thomeer, Michiel; Vanhove, Karolien; Vandeurzen, K.; Sadowska, A.; Reekmans, Gunter; Adriaensens, Peter

    2013-01-01

    Introduction. Lung cancer is the leading cause of cancer death worldwide. An effective method which allows to detect lung cancer is urgently needed. Accumulating evidence shows that the metabolism of cancer cells differs from that of normal cells(1). Disturbances in biochemical pathways which occur during the development of cancer provoke changes in the metabolic phenotype(2). Objective. To determine the metabolic phenotype of lung cancer by means of proton nuclear magnetic resonance (1H-...

  17. Metabonomic study of human serum in gallbladder cancer by 1H NMR spectroscopy

    Gallbladder carcinoma (GBC) is one of the most lethal malignancies of upper gastrointestinal tract and it has the highest mortality rate in Chile and India. It has a very high incidence rates in northern India therefore it is also called as an Indian disease. There are several factors which play important role in development of gallbladder cancer including long-standing stones in gallbladder and alterations in composition of bile. Studies on gallstones and gallbladder tissues revealed that benign group can easily be discriminated from malignant group. Many proteomic studies have been performed for different cancers and several responsible serum protein markers have been identified but there is no such metabonomics study that shows the presence of any biomarker associated with gallbladder carcinoma. Identification of such biomarker would help immensely in the diagnostic of GBC. For this study we have collected blood samples (70; including patients from Chronic Cholecystitis (CC), XanthoGranulomatous Cholecystitis (XGC) and Gallbladder Cancer (GBC)) post-operatively (immediately after surgery) from patient undergoing cholecystectomy in Department of Surgical Gastroenterology, SGPGIMS. Control samples were also collected from 20 volunteers after 12 hrs of fasting. 4 ml of blood sample was collected and was allowed to clot in plastic tube for 30 min at room temperature in incubator. The serum was collected by centrifugation and samples were stored at -80 deg C till NMR experiments. 400 μL of serum was used for recording NMR spectra. NMR spectra were recorded at Bruker Avance 800 MHz spectrometer using CPMG pulse sequence with water presaturation. Control serum shows presence of various amino acids and low molecular weight metabolites. Detailed multivariate analysis along with markers found in serum associated with GBC will be presented. (author)

  18. 1H NMR Spectroscopy and Multivariate Analysis of Monovarietal EVOOs as a Tool for Modulating Coratina-Based Blends

    Laura Del Coco

    2014-04-01

    Full Text Available Coratina cultivar-based olives are very common among 100% Italian extra virgin olive oils (EVOOs. Often, the very spicy character of this cultivar, mostly due to the high polyphenols concentration, requires blending with other “sweetener” oils. In this work, monovarietal EVOO samples from the Coratina cultivar (Apulia, Italy were investigated and compared with monovarietal EVOO from native or recently introduced Apulian (Italy cultivars (Ogliarola Garganica, Ogliarola Barese, Cima di Mola, Peranzana, Picholine, from Calabria (Italy (Carolea and Rossanese and from other Mediterranean countries, such as Spain (Picual and Greece (Kalamata and Koroneiki by 1H NMR spectroscopy and multivariate analysis (principal component analysis (PCA. In this regard, NMR signals could allow a first qualitative evaluation of the chemical composition of EVOO and, in particular, of its minor component content (phenols and aldehydes, an intrinsic behavior of EVOO taste, related to the cultivar and geographical origins. Moreover, this study offers an opportunity to address blended EVOOs tastes by using oils from a specific region or country of origin.

  19. Quantitative 1 H NMR spectroscopy analysis of the poly(3-hydroxy alkanoate) extracted from Rhizobium meliloti cells

    1H NMR analysis was carried out to determine the nature and the concentration of the poly(3-hydroxyalkanoate) (PHA) accumulated by Rhizobium meliloti M5N1. The PHA was identified as being poly(3-hydroxybutyrate) (PHB). Benzene was shown to meet all the requirements of an internal reference for PHB quantification. NMR data were in good agreement with corresponding data obtained by Gas Chromatography (GC) analysis. (authors). 4 refs., 2 figs

  20. Coal structure at reactive sites by sup 1 H- sup 13 C- sup 19 F double cross polarization (DCP)/MAS sup 13 C NMR spectroscopy

    Hagaman, E.W.; Woody, M.C. (Oak Ridge National Lab., TN (USA))

    1989-01-01

    The solid state NMR technique, {sup 1}H-{sup 13}C-{sup 31}P double cross polarization (DCP)/MAS {sup 13}C-NMR spectroscopy, uses the direct dipolar interaction between {sup 13}C-{sup 31}P spin pairs in organophosphorus substances to identify the subset of carbons within a spherical volume element of 0.4 nm radius centered on the {sup 31}P atom. In combination with chemical manipulation of coals designed to introduce phosphorus containing functionality into the organic matrix, the NMR experiment becomes a method to examine selectively the carbon bonding network at the reactive sites in the coal. This approach generates a statistical structure description of the coal at the reaction centers in contrast to bulk carbon characterization using conventional {sup 1}H-{sup 13}C CP/MAS {sup 13}C NMR spectroscopy. 3 refs.

  1. Real-Time Monitoring of New Delhi Metallo-β-Lactamase Activity in Living Bacterial Cells by 1H NMR Spectroscopy**

    Ma, Junhe; McLeod, Sarah; MacCormack, Kathleen; Sriram, Shubha; Gao, Ning; Breeze, Alexander L.; Hu, Jun

    2014-01-01

    Disconnections between in vitro responses and those observed in whole cells confound many attempts to design drugs in areas of serious medical need. A method based on 1D 1H NMR spectroscopy is reported that affords the ability to monitor the hydrolytic decomposition of the carbapenem antibiotic meropenem inside Escherichia coli cells expressing New Delhi metallo-β-lactamase subclass 1 (NDM-1), an emerging antibiotic-resistance threat. Cell-based NMR studies demonstrated that two known NDM-1 i...

  2. Domain structure of antithrombin III. Tentative localization of the heparin binding region using 1H NMR spectroscopy

    The denaturation of human and bovine antithrombin III by guanidine hydrochloride has been followed by 1H NMR spectroscopy. The same unfolding transition seen previously from circular dichroism studies at low denaturant concentration was detected here by discontinuous changes in the chemical shifts of the C(2) protons of two of the five histidines in human antithrombin III and of three of the six histidines in bovine antithrombin III. These two histidines in human antithrombin III are assigned to residue 1 and, more tentatively, to residue 65. Two of the three histidines similarly affected in the bovine protein appear to be homologous to residues in the human protein. This supports the proposal of similar structures for the two proteins. In the presence of heparin, the discontinuous titration behavior of these histidine resonances is shifted to higher denaturant concentration, reflecting the stabilization of the easily unfolded first domain of the protein by bound heparin. From the tentative assignment of one of these resonances to histidine-1, it is proposed that the heparin binding site of antithrombin III is located in the N-terminal region and that this region forms a separate domain from the rest of the protein. The pattern of disulfide linkages is such that this domain may well extend from residue 1 to at least residue 128. Thermal denaturation also leads to major perturbation of these two histidine resonances in human antithrombin III, though stable intermediates in the unfolding were not detected

  3. Gender-specific metabolomic profiling of obesity in leptin-deficient ob/ob mice by 1H NMR spectroscopy.

    Eun-Young Won

    Full Text Available Despite the numerous metabolic studies on obesity, gender bias in obesity has rarely been investigated. Here, we report the metabolomic analysis of obesity by using leptin-deficient ob/ob mice based on the gender. Metabolomic analyses of urine and serum from ob/ob mice compared with those from C57BL/6J lean mice, based on the (1H NMR spectroscopy in combination with multivariate statistical analysis, revealed clear metabolic differences between obese and lean mice. We also identified 48 urine and 22 serum metabolites that were statistically significantly altered in obese mice compared to lean controls. These metabolites are involved in amino acid metabolism (leucine, alanine, ariginine, lysine, and methionine, tricarbocylic acid cycle and glucose metabolism (pyruvate, citrate, glycolate, acetoacetate, and acetone, lipid metabolism (cholesterol and carnitine, creatine metabolism (creatine and creatinine, and gut-microbiome-derived metabolism (choline, TMAO, hippurate, p-cresol, isobutyrate, 2-hydroxyisobutyrate, methylamine, and trigonelline. Notably, our metabolomic studies showed distinct gender variations. The obese male mice metabolism was specifically associated with insulin signaling, whereas the obese female mice metabolism was associated with lipid metabolism. Taken together, our study identifies the biomarker signature for obesity in ob/ob mice and provides biochemical insights into the metabolic alteration in obesity based on gender.

  4. Identification and quantification of the main organic components of vinegars by high resolution 1H NMR spectroscopy

    A detailed analysis of the proton high-field NMR spectra of vinegars (in particular of Italian balsamic vinegars) is reported. A large number of organic substances belonging to different classes, such as carbohydrates, alcohols, organic acids, volatile compounds and amino acids, were assigned. The possibility of quantification of the substances identified in the whole vinegar sample, without extraction or pre-concentration steps, was also tested. The data validity was demonstrated in terms of precision, accuracy, repeatability and inter-day reproducibility. The effects of the most critical experimental parameters (sample concentration, water suppression and relaxation time) on the analysis response were also discussed. 1H NMR results were compared with those obtained by traditional techniques (GC-MS, titrations), and good correlations were obtained. The results showed that 1H NMR with water suppression allows a rapid, simultaneous determination of carbohydrates (glucose and fructose), organic acids (acetic, formic, lactic, malic, citric, succinic and tartaric acids), alcohols and polyols (ethanol, acetoin, 2,3-butanediol, hydroxymethylfurfural), and volatile substances (ethyl acetate) in vinegar samples. On the contrary, the amino acid determination without sample pre-concentration was critical. The 1H NMR method proposed was applied to different samples of vinegars, allowing, in particular, the discrimination of vinegars and balsamic vinegars

  5. Identification and quantification of the main organic components of vinegars by high resolution {sup 1}H NMR spectroscopy

    Caligiani, A. [Dipartimento di Chimica Organica e Industriale, Universita degli Studi di Parma, Via Usberti 17A, 43100-Parma (Italy)]. E-mail: augusta.caligiani@unipr.it; Acquotti, D. [Centro Interfacolta Misure, Universita degli Studi di Parma, Via Usberti 23A, 43100-Parma (Italy); Palla, G. [Dipartimento di Chimica Organica e Industriale, Universita degli Studi di Parma, Via Usberti 17A, 43100-Parma (Italy); Bocchi, V. [Dipartimento di Chimica Organica e Industriale, Universita degli Studi di Parma, Via Usberti 17A, 43100-Parma (Italy)

    2007-02-28

    A detailed analysis of the proton high-field NMR spectra of vinegars (in particular of Italian balsamic vinegars) is reported. A large number of organic substances belonging to different classes, such as carbohydrates, alcohols, organic acids, volatile compounds and amino acids, were assigned. The possibility of quantification of the substances identified in the whole vinegar sample, without extraction or pre-concentration steps, was also tested. The data validity was demonstrated in terms of precision, accuracy, repeatability and inter-day reproducibility. The effects of the most critical experimental parameters (sample concentration, water suppression and relaxation time) on the analysis response were also discussed. {sup 1}H NMR results were compared with those obtained by traditional techniques (GC-MS, titrations), and good correlations were obtained. The results showed that {sup 1}H NMR with water suppression allows a rapid, simultaneous determination of carbohydrates (glucose and fructose), organic acids (acetic, formic, lactic, malic, citric, succinic and tartaric acids), alcohols and polyols (ethanol, acetoin, 2,3-butanediol, hydroxymethylfurfural), and volatile substances (ethyl acetate) in vinegar samples. On the contrary, the amino acid determination without sample pre-concentration was critical. The {sup 1}H NMR method proposed was applied to different samples of vinegars, allowing, in particular, the discrimination of vinegars and balsamic vinegars.

  6. Identification and quantification of the main organic components of vinegars by high resolution 1H NMR spectroscopy.

    Caligiani, A; Acquotti, D; Palla, G; Bocchi, V

    2007-02-28

    A detailed analysis of the proton high-field NMR spectra of vinegars (in particular of Italian balsamic vinegars) is reported. A large number of organic substances belonging to different classes, such as carbohydrates, alcohols, organic acids, volatile compounds and amino acids, were assigned. The possibility of quantification of the substances identified in the whole vinegar sample, without extraction or pre-concentration steps, was also tested. The data validity was demonstrated in terms of precision, accuracy, repeatability and inter-day reproducibility. The effects of the most critical experimental parameters (sample concentration, water suppression and relaxation time) on the analysis response were also discussed. (1)H NMR results were compared with those obtained by traditional techniques (GC-MS, titrations), and good correlations were obtained. The results showed that (1)H NMR with water suppression allows a rapid, simultaneous determination of carbohydrates (glucose and fructose), organic acids (acetic, formic, lactic, malic, citric, succinic and tartaric acids), alcohols and polyols (ethanol, acetoin, 2,3-butanediol, hydroxymethylfurfural), and volatile substances (ethyl acetate) in vinegar samples. On the contrary, the amino acid determination without sample pre-concentration was critical. The (1)H NMR method proposed was applied to different samples of vinegars, allowing, in particular, the discrimination of vinegars and balsamic vinegars. PMID:17386654

  7. Determination and Comparison of Seed Oil Triacylglycerol Composition of Various Soybeans (Glycine max (L. Using 1H-NMR Spectroscopy

    Won Woo Kim

    2013-11-01

    Full Text Available Seed oil triacylglycerol (TAG composition of 32 soybean varieties were determined and compared using 1H-NMR. The contents of linolenic (Ln, linoleic (L, and oleic (O ranged from 10.7% to 19.3%, 37.4%–50.1%, and 15.7%–34.1%, respectively. As is evident, linoleic acid was the major fatty acid of soybean oil. Compositional differences among the varieties were observed. Natural oils containing unsaturated groups have been regarded as important nutrient and cosmetic ingredients because of their various biological activities. The TAG profiles of the soy bean oils could be useful for distinguishing the origin of seeds and controlling the quality of soybean oils. To the best of our knowledge, this is the first study in which the TAG composition of various soybean oils has been analyzed using the 1H-NMR method.

  8. Conformational studies on 2-substituted ethanesulfonates in aqueous solution by 1H NMR spectroscopy and DFT calculations

    Musio, Roberta; Sciacovelli, Oronzo

    2009-09-01

    The conformation of some 2-substituted sodium ethanesulfonates exerting biological functions, XCH 2CH 2SO 3Na (X = S -, Br, Cl, OH, NH 2, SH), has been investigated in aqueous solution by 1H NMR spectroscopy. Potential energy curves for rotation about the C-C bond have been calculated at DFT level of theory (B3LYP/6-311++G(2d,p)) in vacuum and in water (by IEF-PCM method). As concerning dianionic coenzyme M (X = S -), 2-bromo- and 2-chloroethanesulfonate, in vacuum the torsional potential curves and the variations of atomic charges and geometric parameters suggest that electrostatic and steric repulsions between the substituent X and -SO3- moiety determine the preference for anti conformer. In isethionate (X = OH), anionic taurine (X = NH 2), and coenzyme M (X = SH), the formation of an intramolecular hydrogen bond stabilizes also gauche-like conformers and the torsional potential curves exhibit two minima. According to Natural Bond Orbital analysis, hydrogen bond can be ascribed to electron transfer from two oxygen lone-pairs of the -SO3- moiety to the antibonding Y-H orbital of the substituent X. In all the compounds examined, hyperconjugative interactions tend to stabilize the gauche conformers with respect to the anti one. This means that conformational preferences in vacuum are determined by a counterbalancing of electrostatic, steric, and hyperconjugative interactions. Calculations in vacuum are not in agreement with the experimental conformational behaviour of the compounds examined. In order to reproduce the experimental results at least qualitatively, solvent effect must be introduced.

  9. Strategies for organic impurity quantification by {sup 1}H NMR spectroscopy: Constrained total-line-shape fitting

    Soininen, Pasi [University of Kuopio, Department of Chemistry, P.O. Box 1627, 70211 Kuopio (Finland)]. E-mail: Pasi.Soininen@uku.fi; Haarala, Jorma [Orion Pharma, P.O. Box 65, 02101 Espoo (Finland); Vepsaelaeinen, Jouko [University of Kuopio, Department of Chemistry, P.O. Box 1627, 70211 Kuopio (Finland); Niemitz, Matthias [PERCH Solutions Ltd., Microkatu 1, 70211 Kuopio (Finland); Laatikainen, Reino [University of Kuopio, Department of Chemistry, P.O. Box 1627, 70211 Kuopio (Finland)

    2005-06-29

    A constrained total-line-shape (CTLS) fitting strategy for organic impurity analysis from {sup 1}H NMR spectra was developed and assessed by studying two examples. In general, total-line-shape fitting allows integration of overlapping lines without suffering from baseline artifacts as much as traditional integration methods. It is shown here that the constrained total-line-shape fitting, where the spectral structures of the multiplets to be fitted are taken into account in form of constraints, allows quantification of seriously overlapping lines and when the signals are close to the root of major signals. Also, a method for removal of {sup 13}C satellite signals is described. The results indicate that our approach significantly improves the usefulness of qNMR in impurity analysis and that impurity levels of 0.1 mol%, which in some cases means down to 0.01 wt%, can be easily determined with relative standard error smaller than 10%.

  10. Rapid approach to identify the presence of Arabica and Robusta species in coffee using 1H NMR spectroscopy.

    Monakhova, Yulia B; Ruge, Winfried; Kuballa, Thomas; Ilse, Maren; Winkelmann, Ole; Diehl, Bernd; Thomas, Freddy; Lachenmeier, Dirk W

    2015-09-01

    NMR spectroscopy was used to verify the presence of Arabica and Robusta species in coffee. Lipophilic extracts of authentic roasted and green coffees showed the presence of established markers for Robusta (16-O-methylcafestol (16-OMC)) and for Arabica (kahweol). The integration of the 16-OMC signal (δ 3.165 ppm) was used to estimate the amount of Robusta in coffee blends with an approximate limit of detection of 1-3%. The method was successfully applied for the analysis of 77 commercial coffee samples (coffee pods, coffee capsules, and coffee beans). Furthermore, principal component analysis (PCA) was applied to the spectra of lipophilic and aqueous extracts of 20 monovarietal authentic samples. Clusters of the two species were observed. NMR spectroscopy can be used as a rapid prescreening tool to discriminate Arabica and Robusta coffee species before the confirmation applying the official method. PMID:25842325

  11. Quantitative evaluation of the lactate signal loss and its spatial dependence in press localized (1)H NMR spectroscopy.

    Jung, W I; Bunse, M; Lutz, O

    2001-10-01

    Localized (1)H NMR spectroscopy using the 90 degrees -t(1)-180 degrees -t(1)+t(2)-180 degrees -t(2)-Acq. PRESS sequence can lead to a signal loss for the lactate doublet compared with signals from uncoupled nuclei which is dependent on the choice of t(1) and t(2). The most striking signal loss of up to 78% of the total signal occurs with the symmetrical PRESS sequence (t(1)=t(2)) at an echo time of 2/J (approximately 290 ms). Calculations have shown that this signal loss is related to the pulse angle distributions produced by the two refocusing pulses which leads to the creation of single quantum polarization transfer (PT) as well as to not directly observable states (NDOS) of the lactate AX(3) spin system: zero- and multiple-quantum coherences, and longitudinal spin orders. In addition, the chemical shift dependent voxel displacement (VOD) leads to further signal loss. By calculating the density operator for various of the echo times TE=n/J, n=1, 2, 3,..., we calculated quantitatively the contributions of these effects to the signal loss as well as their spatial distribution. A maximum signal loss of 75% can be expected from theory for the symmetrical PRESS sequence and TE=2/J for Hamming filtered sinc pulses, whereby 47% are due to the creation of NDOS and up to 28% arise from PT. Taking also the VOD effect into account (2 mT/m slice selection gradients, 20-mm slices) leads to 54% signal loss from NDOS and up to 24% from PT, leading to a maximum signal loss of 78%. Using RE-BURP pulses with their more rectangular pulse angle distributions reduces the maximum signal loss to 44%. Experiments at 1.5 T using a lactate solution demonstrated a maximum lactate signal loss for sinc pulses of 82% (52% NDOS, 30% PT) at TE=290 ms using the symmetrical PRESS sequence. The great signal loss and its spatial distribution is of importance for investigations using a symmetrical PRESS sequence at TE=2/J. PMID:11567573

  12. Quantitative Evaluation of the Lactate Signal Loss and Its Spatial Dependence in PRESS Localized 1H NMR Spectroscopy

    Jung, Wulf-Ingo; Bunse, Michael; Lutz, Otto

    2001-10-01

    Localized 1H NMR spectroscopy using the 90°-t1-180°-t1+t2-180°-t2-Acq. PRESS sequence can lead to a signal loss for the lactate doublet compared with signals from uncoupled nuclei which is dependent on the choice of t1 and t2. The most striking signal loss of up to 78% of the total signal occurs with the symmetrical PRESS sequence (t1=t2) at an echo time of 2/J (≃290 ms). Calculations have shown that this signal loss is related to the pulse angle distributions produced by the two refocusing pulses which leads to the creation of single quantum polarization transfer (PT) as well as to not directly observable states (NDOS) of the lactate AX3 spin system: zero- and multiple-quantum coherences, and longitudinal spin orders. In addition, the chemical shift dependent voxel displacement (VOD) leads to further signal loss. By calculating the density operator for various of the echo times TE=n/J, n=1, 2, 3, …, we calculated quantitatively the contributions of these effects to the signal loss as well as their spatial distribution. A maximum signal loss of 75% can be expected from theory for the symmetrical PRESS sequence and TE=2/J for Hamming filtered sinc pulses, whereby 47% are due to the creation of NDOS and up to 28% arise from PT. Taking also the VOD effect into account (2 mT/m slice selection gradients, 20-mm slices) leads to 54% signal loss from NDOS and up to 24% from PT, leading to a maximum signal loss of 78%. Using RE-BURP pulses with their more rectangular pulse angle distributions reduces the maximum signal loss to 44%. Experiments at 1.5 T using a lactate solution demonstrated a maximum lactate signal loss for sinc pulses of 82% (52% NDOS, 30% PT) at TE=290 ms using the symmetrical PRESS sequence. The great signal loss and its spatial distribution is of importance for investigations using a symmetrical PRESS sequence at TE=2/J.

  13. Metabolic analysis of elicited cell suspension cultures of Cannabis sativa L. by 1H-NMR spectroscopy

    Peč, Jaroslav; Flores-Sanchez, Isvett Josefina; Choi, Young Hae; Verpoorte, Robert

    2010-01-01

    Abstract Cannabis sativa L. plants produce a diverse array of secondary metabolites. Cannabis cell cultures were treated with jasmonic acid (JA) and pectin as elicitors to evaluate their effect on metabolism from two cell lines using NMR spectroscopy and multivariate data analysis. According to principal component analysis (PCA) and partial least square-discriminant analysis (PLS-DA), the chloroform extract of the pectin-treated cultures were more different than control and JA-trea...

  14. Local environment and composition of magnesium gallium layered double hydroxides determined from solid-state 1H and 71Ga NMR spectroscopy

    Petersen, Line B.; Lipton, Andrew S.; Zorin, Vadim; Nielsen, Ulla Gro

    2014-11-01

    Ordering of gallium(III) in a series of magnesium gallium layered double hydroxides (LDH’s), [Mg1-xGax(OH)2(NO3)x yH2O], was determined using solid-state 1H and 71Ga NMR spectroscopy. Depletion of Ga in these LDH’s is demonstrated to be the result of soluble [Ga(OH)4]-complexes formed during synthesis.

  15. Local environment and composition of magnesium gallium layered double hydroxides determined from solid-state 1H and 71Ga NMR spectroscopy

    Boisen Petersen, Line; Lipton, Andrew S.; Zorin, Vadim;

    2014-01-01

    Ordering of gallium(III) in a series of magnesium gallium (MgGa) layered double hydroxides (LDHs), [Mg1−xGax(OH)2(NO3)x·yH2O] was investigated using solid-state 1H and 71Ga NMR spectroscopy as well as powder X-ray diffraction. Three different proton environments from Mg3single bondOH, Mg2Gasingle...

  16. Assignment of the side-chain 1H and 13C resonances of interleukin-1β using double- and triple-resonance heteronuclear three-dimensional NMR spectroscopy

    The assignment of the aliphatic 1H and 13C resonances of IL-1β, a protein of 153 residues and molecular mass 17.4 kDa, is presented by use of a number of novel three-dimensional (3D) heteronuclear NMR experiments which rely on large heteronuclear one-bond J couplings to transfer magnetization and establish through-bond connectivities. These 3D NMR experiments circumvent problems traditionally associated with the application of conventional 2D 1H-1H correlation experiments to proteins of this size, in particular the extensive chemical shift overlap which precludes the interpretation of the spectra and the reduced sensitivity arising from 1H line widths that are often significantly larger than the 1H-1H J couplings. The assignment proceeds in two stages. In the first step the 13Cα chemical shifts are correlated with the NH and 15N chemical shifts by a 3D triple-resonance NH-15N-13Cα (HNCA) correlation experiment which reveals both intraresidue NH(i)-15N(i)-13Cα(i) and some weaker interresidue NH(i)-15N(i)-Cα(i-1) correlations, the former via intraresidue one-bond 1JNCα and the latter via interresidue two-bond 2HNCα couplings. The second step involves the identification of side-chain spin systems by 3D 1H-13C-13C-1H correlated (HCCH-COSY) and 3D 1H-13C-13C-1H total correlated (HCCH-TOCSY) spectroscopy, the latter making use of isotropic mixing of 13C magnetization to obtain relayed connectivities along the side chains. The authors were able to obtain complete 1H and 13C side-chain assignments for all residues, with the exception of 4 (out of a total of 15) lysine residues for which partial assignments were obtained

  17. 1H NMR-based spectroscopy detects metabolic alterations in serum of patients with early-stage ulcerative colitis

    Highlights: •Twenty ulcerative colitis patients and nineteen healthy controls were enrolled. •Increased 3-hydroxybutyrate, glucose, phenylalanine, and decreased lipid were found. •We report early stage diagnosis of ulcerative colitis using NMR-based metabolomics. -- Abstract: Ulcerative colitis (UC) has seriously impaired the health of citizens. Accurate diagnosis of UC at an early stage is crucial to improve the efficiency of treatment and prognosis. In this study, proton nuclear magnetic resonance (1H NMR)-based metabolomic analysis was performed on serum samples collected from active UC patients (n = 20) and healthy controls (n = 19), respectively. The obtained spectral profiles were subjected to multivariate data analysis. Our results showed that consistent metabolic alterations were present between the two groups. Compared to healthy controls, UC patients displayed increased 3-hydroxybutyrate, β-glucose, α-glucose, and phenylalanine, but decreased lipid in serum. These findings highlight the possibilities of NMR-based metabolomics as a non-invasive diagnostic tool for UC

  18. {sup 1}H NMR-based spectroscopy detects metabolic alterations in serum of patients with early-stage ulcerative colitis

    Zhang, Ying; Lin, Lianjie [Second Department of Gastroenterology, Shengjing Hospital, China Medical University, Shenyang 110004 (China); Xu, Yanbin [Wanlei Life Sciences (Shenyang) Co., Ltd., Shenyang 110179 (China); Lin, Yan; Jin, Yu [Second Department of Gastroenterology, Shengjing Hospital, China Medical University, Shenyang 110004 (China); Zheng, Changqing, E-mail: changqing_zheng@126.com [Second Department of Gastroenterology, Shengjing Hospital, China Medical University, Shenyang 110004 (China)

    2013-04-19

    Highlights: •Twenty ulcerative colitis patients and nineteen healthy controls were enrolled. •Increased 3-hydroxybutyrate, glucose, phenylalanine, and decreased lipid were found. •We report early stage diagnosis of ulcerative colitis using NMR-based metabolomics. -- Abstract: Ulcerative colitis (UC) has seriously impaired the health of citizens. Accurate diagnosis of UC at an early stage is crucial to improve the efficiency of treatment and prognosis. In this study, proton nuclear magnetic resonance ({sup 1}H NMR)-based metabolomic analysis was performed on serum samples collected from active UC patients (n = 20) and healthy controls (n = 19), respectively. The obtained spectral profiles were subjected to multivariate data analysis. Our results showed that consistent metabolic alterations were present between the two groups. Compared to healthy controls, UC patients displayed increased 3-hydroxybutyrate, β-glucose, α-glucose, and phenylalanine, but decreased lipid in serum. These findings highlight the possibilities of NMR-based metabolomics as a non-invasive diagnostic tool for UC.

  19. 1H HR-MAS NMR Spectroscopy and the Metabolite Determination of Typical Foods in Mediterranean Diet

    Carmelo Corsaro

    2015-01-01

    Full Text Available NMR spectroscopy has become an experimental technique widely used in food science. The experimental procedures that allow precise and quantitative analysis on different foods are relatively simple. For a better sensitivity and resolution, NMR spectroscopy is usually applied to liquid sample by means of extraction procedures that can be addressed to the observation of particular compounds. For the study of semisolid systems such as intact tissues, High-Resolution Magic Angle Spinning (HR-MAS has received great attention within the biomedical area and beyond. Metabolic profiling and metabolism changes can be investigated both in animal organs and in foods. In this work we present a proton HR-MAS NMR study on the typical vegetable foods of Mediterranean diet such as the Protected Geographical Indication (PGI cherry tomato of Pachino, the PGI Interdonato lemon of Messina, several Protected Designation of Origin (PDO extra virgin olive oils from Sicily, and the Traditional Italian Food Product (PAT red garlic of Nubia. We were able to identify and quantify the main metabolites within the studied systems that can be used for their characterization and authentication.

  20. Local environment and composition of magnesium gallium layered double hydroxides determined from solid-state {sup 1}H and {sup 71}Ga NMR spectroscopy

    Petersen, Line Boisen [Department of Physics, Chemistry and Pharmacy, University of Southern Denmark, Campusvej 55, 5230 Odense M (Denmark); Lipton, Andrew S. [Biological Sciences Division, Pacific Northwest National Laboratory, 902 Battelle Boulevard, Richland, WA 99354 (United States); Zorin, Vadim [Agilent Technologies UK Ltd., 6 Mead Road, Yarnton, Oxfordshire OX5 1QU (United Kingdom); Nielsen, Ulla Gro, E-mail: ugn@sdu.dk [Department of Physics, Chemistry and Pharmacy, University of Southern Denmark, Campusvej 55, 5230 Odense M (Denmark)

    2014-11-15

    Ordering of gallium(III) in a series of magnesium gallium (MgGa) layered double hydroxides (LDHs), [Mg{sub 1−x}Ga{sub x}(OH){sub 2}(NO{sub 3}){sub x}·yH{sub 2}O] was investigated using solid-state {sup 1}H and {sup 71}Ga NMR spectroscopy as well as powder X-ray diffraction. Three different proton environments from Mg{sub 3}-OH, Mg{sub 2}Ga-OH and intergallery water molecules were assigned and quantified using ({sup 1}H,{sup 71}Ga) HETCOR and {sup 1}H MAS NMR. A single {sup 71}Ga site originating from the unique Ga site in the MgGa LDH's was observed in {sup 71}Ga MAS and 3QMAS NMR spectra. Both {sup 1}H MAS NMR spectra recorded at 21.1 T (900 MHz) and elemental analysis show that the synthesized MgGa LDH's had a lower Mg:Ga ratio than that of the starting reactant solution. The origin of this is the formation of soluble [Ga(OH){sub 4}]{sup −} complexes formed during synthesis, and not due to formation of insoluble gallium (oxy)hydroxides. No sign of Ga-O-Ga connectivities or defects were detected for the MgGa LDH's. - Graphical abstract: Two types of hydroxides groups are observed in magnesium gallium layered double hydroxides revealing an ordering of Ga in the cation layer. - Highlights: • Ga is ordered in our magnesium gallium layered double hydroxides. • Ga depletion due to formation of soluble Ga complexes during synthesis. • No sign of Ga rich regions in magnesium gallium LDHs. • Solid state {sup 1}H and {sup 71}Ga give detailed insight into the structure.

  1. Local environment and composition of magnesium gallium layered double hydroxides determined from solid-state 1H and 71Ga NMR spectroscopy

    Ordering of gallium(III) in a series of magnesium gallium (MgGa) layered double hydroxides (LDHs), [Mg1−xGax(OH)2(NO3)x·yH2O] was investigated using solid-state 1H and 71Ga NMR spectroscopy as well as powder X-ray diffraction. Three different proton environments from Mg3-OH, Mg2Ga-OH and intergallery water molecules were assigned and quantified using (1H,71Ga) HETCOR and 1H MAS NMR. A single 71Ga site originating from the unique Ga site in the MgGa LDH's was observed in 71Ga MAS and 3QMAS NMR spectra. Both 1H MAS NMR spectra recorded at 21.1 T (900 MHz) and elemental analysis show that the synthesized MgGa LDH's had a lower Mg:Ga ratio than that of the starting reactant solution. The origin of this is the formation of soluble [Ga(OH)4]− complexes formed during synthesis, and not due to formation of insoluble gallium (oxy)hydroxides. No sign of Ga-O-Ga connectivities or defects were detected for the MgGa LDH's. - Graphical abstract: Two types of hydroxides groups are observed in magnesium gallium layered double hydroxides revealing an ordering of Ga in the cation layer. - Highlights: • Ga is ordered in our magnesium gallium layered double hydroxides. • Ga depletion due to formation of soluble Ga complexes during synthesis. • No sign of Ga rich regions in magnesium gallium LDHs. • Solid state 1H and 71Ga give detailed insight into the structure

  2. Characterisation of PEGylated PLGA nanoparticles comparing the nanoparticle bulk to the particle surface using UV/vis spectroscopy, SEC, 1H NMR spectroscopy, and X-ray photoelectron spectroscopy

    Graphical abstract: - Highlights: • We compared nanoparticles prepared on the basis of PLGA and PEG–PLGA for their polymeric composition in the particle bulk and on the surface. • We validated three analytical methods (UV/vis, SEC, 1H NMR) for quantification of the polymeric stabiliser PVA and 1H NMR for the quantification of PEG. • In the case of PEG–PLGA as starting material we observed significant PEG contents not only on the surface but even in the particle bulk. • We observed an unexpected accumulation of the polymeric stabiliser PVA on PEGylated particle surfaces. - Abstract: Hypothesis: The bulk and the surface structure of nanoparticles based on poly(lactic-co-glycolic acid) (PLGA) and PLGA–PEG copolymer is expected to consist of different polymer compositions. An enrichment of hydrophilic PEG on the surface in combination with an accumulation of PLGA in the bulk is anticipated. Hence, the imbalance between bulk and surface composition should be detectable by suitable analytical methods. Experiments: Nanoparticles were assembled using an emulsion-evaporation method with polyvinyl alcohol (PVA) as stabiliser. Mixtures of PLGA and PLGA–PEG copolymer were applied to achieve variably PEGylated nanoparticles. The nanoparticle composition was analysed with respect to PLGA, PVA and PEG, comparing the polymer content of the nanoparticle bulk to the surface. For the bulk, PVA was quantified by a UV/vis spectroscopic method as well as size exclusion chromatography (SEC), and 1H nuclear magnetic resonance (NMR) spectroscopy. PEG determination of the bulk was carried out using quantitative 1H NMR spectroscopy. Surface composition was investigated by X-ray photoelectron spectroscopy (XPS). Findings: For the characterisation of the polymer composition 1H NMR, SEC, and XPS-methods were successfully established and validated. Unexpectedly, a significant PEG content was detected within the particle bulk. The comparison of nanoparticle bulk to surface showed

  3. Characterisation of PEGylated PLGA nanoparticles comparing the nanoparticle bulk to the particle surface using UV/vis spectroscopy, SEC, {sup 1}H NMR spectroscopy, and X-ray photoelectron spectroscopy

    Spek, S.; Haeuser, M. [Institute of Pharmaceutical Technology and Biopharmacy, University of Muenster, Corrensstrasse 48, 48149 Muenster (Germany); Schaefer, M.M. [nanoAnalytics, Heisenbergstrasse 11, 48149 Muenster (Germany); Langer, K., E-mail: k.langer@wwu.de [Institute of Pharmaceutical Technology and Biopharmacy, University of Muenster, Corrensstrasse 48, 48149 Muenster (Germany)

    2015-08-30

    Graphical abstract: - Highlights: • We compared nanoparticles prepared on the basis of PLGA and PEG–PLGA for their polymeric composition in the particle bulk and on the surface. • We validated three analytical methods (UV/vis, SEC, {sup 1}H NMR) for quantification of the polymeric stabiliser PVA and {sup 1}H NMR for the quantification of PEG. • In the case of PEG–PLGA as starting material we observed significant PEG contents not only on the surface but even in the particle bulk. • We observed an unexpected accumulation of the polymeric stabiliser PVA on PEGylated particle surfaces. - Abstract: Hypothesis: The bulk and the surface structure of nanoparticles based on poly(lactic-co-glycolic acid) (PLGA) and PLGA–PEG copolymer is expected to consist of different polymer compositions. An enrichment of hydrophilic PEG on the surface in combination with an accumulation of PLGA in the bulk is anticipated. Hence, the imbalance between bulk and surface composition should be detectable by suitable analytical methods. Experiments: Nanoparticles were assembled using an emulsion-evaporation method with polyvinyl alcohol (PVA) as stabiliser. Mixtures of PLGA and PLGA–PEG copolymer were applied to achieve variably PEGylated nanoparticles. The nanoparticle composition was analysed with respect to PLGA, PVA and PEG, comparing the polymer content of the nanoparticle bulk to the surface. For the bulk, PVA was quantified by a UV/vis spectroscopic method as well as size exclusion chromatography (SEC), and {sup 1}H nuclear magnetic resonance (NMR) spectroscopy. PEG determination of the bulk was carried out using quantitative {sup 1}H NMR spectroscopy. Surface composition was investigated by X-ray photoelectron spectroscopy (XPS). Findings: For the characterisation of the polymer composition {sup 1}H NMR, SEC, and XPS-methods were successfully established and validated. Unexpectedly, a significant PEG content was detected within the particle bulk. The comparison of

  4. Simultaneous Analysis of Major Coenzymes of Cellular Redox Reactions and Energy Using ex Vivo (1)H NMR Spectroscopy.

    Nagana Gowda, G A; Abell, Lauren; Lee, Chi Fung; Tian, Rong; Raftery, Daniel

    2016-05-01

    Coenzymes of cellular redox reactions and cellular energy mediate biochemical reactions fundamental to the functioning of all living cells. Despite their immense interest, no simple method exists to gain insights into their cellular concentrations in a single step. We show that a simple (1)H NMR experiment can simultaneously measure oxidized and reduced forms of nicotinamide adenine dinucleotide (NAD(+) and NADH), oxidized and reduced forms of nicotinamide adenine dinucleotide phosphate (NADP(+) and NADPH), and adenosine triphosphate (ATP) and its precursors, adenosine diphosphate (ADP) and adenosine monophosphate (AMP), using mouse heart, kidney, brain, liver, and skeletal muscle tissue extracts as examples. Combining 1D/2D NMR experiments, chemical shift libraries, and authentic compound data, reliable peak identities for these coenzymes have been established. To assess this methodology, cardiac NADH and NAD(+) ratios/pool sizes were measured using mouse models with a cardiac-specific knockout of the mitochondrial Complex I Ndufs4 gene (cKO) and cardiac-specific overexpression of nicotinamide phosphoribosyltransferase (cNAMPT) as examples. Sensitivity of NAD(+) and NADH to cKO or cNAMPT was observed, as anticipated. Time-dependent investigations showed that the levels of NADH and NADPH diminish by up to ∼50% within 24 h; concomitantly, NAD(+) and NADP(+) increase proportionately; however, degassing the sample and flushing the sample tubes with helium gas halted such changes. The analysis protocol along with the annotated characteristic fingerprints for each coenzyme is provided for easy identification and absolute quantification using a single internal reference for routine use. The ability to visualize the ubiquitous coenzymes fundamental to cellular functions, simultaneously and reliably, offers a new avenue to interrogate the mechanistic details of cellular function in health and disease. PMID:27043450

  5. Rapid identification of osmolytes in tropical microalgae and cyanobacteria by (1)H HR-MAS NMR spectroscopy.

    Zea Obando, Claudia; Linossier, Isabelle; Kervarec, Nelly; Zubia, Mayalen; Turquet, Jean; Faÿ, Fabienne; Rehel, Karine

    2016-06-01

    In this study, we report the chemical characterization of 47 tropical microalgae and cyanobacteria by HR-MAS. The generated data confirm the interest of HR-MAS as a rapid screening technique with the major advantage of its easiness. The sample is used as powder of freeze-dried microalgae without any extraction process before acquisition. The spectral fingerprints of strains are then tested as variables for a chemotaxonomy study to discriminate cyanobacteria and dinoflagellates. The individual factor map generated by PCA analysis succeeds in separating the two groups, essentially thanks to the presence of specific carbohydrates. Furthermore, more resolved signals enable to identify many osmolytes. More precisely the characteristics δ of 2-O-alpha-D-glucosylglycerol (GG) are observed in all 21 h-MAS spectra of tropical cyanobacteria. After specific extraction, complementary analysis by 1D and 2D-NMR spectroscopies validates the identification of this osmolyte. PMID:27130130

  6. Sequence-specific interaction of Hoechst 33258 with the minor groove of an adenine-tract DNA duplex studied in solution by 1H NMR spectroscopy.

    Searle, M S; Embrey, K J

    1990-01-01

    The interaction of Hoechst 33258 with the minor groove of the adenine-tract DNA duplex d(CTTTTGCAAAAG)2 has been studied in both D2O and H2O solutions by 1D and 2D 1H NMR spectroscopy. Thirty-one nuclear Overhauser effects between drug and nucleotide protons within the minor groove of the duplex, together with ring-current induced perturbations to the chemical shifts of basepair and deoxyribose protons, define the position and orientation of the bound dye molecules. Two drug molecules bind co...

  7. Uses of 1H NMR and 13C NMR spectroscopy in studies of phenylenedioxydiacetamides complexation with the cations of calcium and potassium in solution

    The complexation abilities and the coordination sites of 12 derivatives using infrared, 1HNMR and 13C NMR spectroscopy are analyzed. The spectroscopic results indicate that only the 1,2-phenylenedioxydiacetamides are suitable ligands; the 1,3 derivatives did not react. These ionophors 1-8 represent fourdentale chelating ligands where all four oxygen atmos are involved in bonds to the metal. Independent from its charge one cations is coordinate by two ionophors. (M.J.C.)

  8. 1H and 23Na MAS NMR spectroscopy of cationic species in CO2 selective alkaline earth metal porous silicoaluminophosphates prepared via liquid and solid state ion exchange

    Arévalo-Hidalgo, Ana G.; Dugar, Sneha; Fu, Riqiang; Hernández-Maldonado, Arturo J.

    2012-07-01

    The location of extraframework cations in Sr2+ and Ba2+ ion-exchanged SAPO-34 was estimated by means of 1H and 23Na MAS NMR spectroscopy and spectral deconvolution. Incorporation of the alkaline earth metal cations onto the SAPO framework was achieved via liquid state ion exchange, coupled partial detemplation/solid-state ion exchange, and combination of both techniques. MAS NMR revealed that the level of ion exchange was limited by the presence of protons and sodium cations near hexagonal prisms (site SI), which are relatively difficult to exchange with the alkaline earth metal due to steric and charge repulsion criteria. In addition, the presence of ammonium cations in the supercages facilitated the exchange of otherwise tenacious hydrogen as corroborated by unit cell compositional data as well as enhanced CO2 adsorption at low partial pressures. The extraframework ammonium species were produced from partial detemplation of the structure-directing agent employed for the SAPO-34 synthesis, tetraethylammonium.

  9. 2H and 13C tracer studies of ethanol metabolism by Fourier transform 13C[2H, 1H] NMR difference spectroscopy

    A novel form of NMR difference spectroscopy has been developed to monitor low levels of deuterium incorporation in steroids resulting from ethanol metabolism. Ethanol specifically labeled with 13C and/or 2H was administered to bile fistula rats, and bile acids were collected, derivatized and separated. Subtracting 13C [1H] spectra from 13C[2H,1H] spectra of such samples, where the brackets imply complete noise decoupling of the indicated nuclei, results in difference spectra. These spectra display 13C resonances only from 13C spins which are J-coupled to 2H spins. Particular sites and extents of 2H incorporation along the steroid skeletons could thus be evaluated and compared with GC-MS analysis. A practical lower limit of approximately 20 nanomoles of 13C--2H couples could be observed using this technique, through use of sample microcells, quadrature detection and long-term signal averaging

  10. Interaction of apocytochrome c and derived polypeptide fragments with sodium dodecyl sulfate micelles monitored by photochemically induced dynamic nuclear polarization in 1H NMR and fluorescence spectroscopy

    The topology of apocytochrome c, the heme-free precursor of the mitochondrial protein cytochrome c, was investigated in a lipid-associated form. For this purpose photochemically induced dynamic nuclear polarization 1H nuclear magnetic resonance (CIDNP 1H NMR) spectroscopy and quenching of tryptophan and tyrosine fluorescence by acrylamide were applied to an apocytochrome c-sodium dodecyl sulfate (SDS) micellar system. A pH titration of the chemical shifts of the histidine C2 proton resonances of apocytochrome c, using conventional 1H NMR, yielded pKa's of 5.9 ± 0.1 and 6.2 ± 0.1, which were assigned to histidine-18 and -33 and histidine-26, respectively. In the presence of SDS micelles an average pKa of 8.1 ± 0.1 was obtained for all histidine C2 protons. Photo-CIDNP enhancements of the histidine, tryptophan, and tyrosine residues, contained in the intact apocytochrome c and in chemically and enzymatically prepared fragments of the precursor, were reduced in the presence of SDS micelles. Similarly, the quenching of the tryptophan fluorescence of the polypeptides by acrylamide was diminished in the presence of SDS. These results indicate the aromatic residues studied are localized in the interface of the SDS micelle

  11. Interaction of apocytochrome c and derived polypeptide fragments with sodium dodecyl sulfate micelles monitored by photochemically induced dynamic nuclear polarization in sup 1 H NMR and fluorescence spectroscopy

    Snel, M.M.E.; Kaptein, R.; de Kruijff, B. (Univ. of Utrecht (Netherlands))

    1991-04-09

    The topology of apocytochrome c, the heme-free precursor of the mitochondrial protein cytochrome c, was investigated in a lipid-associated form. For this purpose photochemically induced dynamic nuclear polarization {sup 1}H nuclear magnetic resonance (CIDNP {sup 1}H NMR) spectroscopy and quenching of tryptophan and tyrosine fluorescence by acrylamide were applied to an apocytochrome c-sodium dodecyl sulfate (SDS) micellar system. A pH titration of the chemical shifts of the histidine C2 proton resonances of apocytochrome c, using conventional {sup 1}H NMR, yielded pK{sub a}'s of 5.9 {plus minus} 0.1 and 6.2 {plus minus} 0.1, which were assigned to histidine-18 and -33 and histidine-26, respectively. In the presence of SDS micelles an average pK{sub a} of 8.1 {plus minus} 0.1 was obtained for all histidine C2 protons. Photo-CIDNP enhancements of the histidine, tryptophan, and tyrosine residues, contained in the intact apocytochrome c and in chemically and enzymatically prepared fragments of the precursor, were reduced in the presence of SDS micelles. Similarly, the quenching of the tryptophan fluorescence of the polypeptides by acrylamide was diminished in the presence of SDS. These results indicate the aromatic residues studied are localized in the interface of the SDS micelle.

  12. Calculation of average molecular parameters, functional groups, and a surrogate molecule for heavy fuel oils using 1H and 13C NMR spectroscopy

    Abdul Jameel, Abdul Gani

    2016-04-22

    Heavy fuel oil (HFO) is primarily used as fuel in marine engines and in boilers to generate electricity. Nuclear Magnetic Resonance (NMR) is a powerful analytical tool for structure elucidation and in this study, 1H NMR and 13C NMR spectroscopy were used for the structural characterization of 2 HFO samples. The NMR data was combined with elemental analysis and average molecular weight to quantify average molecular parameters (AMPs), such as the number of paraffinic carbons, naphthenic carbons, aromatic hydrogens, olefinic hydrogens, etc. in the HFO samples. Recent formulae published in the literature were used for calculating various derived AMPs like aromaticity factor 〖(f〗_a), C/H ratio, average paraffinic chain length (¯n), naphthenic ring number 〖(R〗_N), aromatic ring number〖 (R〗_A), total ring number〖 (R〗_T), aromatic condensation index (φ) and aromatic condensation degree (Ω). These derived AMPs help in understanding the overall structure of the fuel. A total of 19 functional groups were defined to represent the HFO samples, and their respective concentrations were calculated by formulating balance equations that equate the concentration of the functional groups with the concentration of the AMPs. Heteroatoms like sulfur, nitrogen, and oxygen were also included in the functional groups. Surrogate molecules were finally constructed to represent the average structure of the molecules present in the HFO samples. This surrogate molecule can be used for property estimation of the HFO samples and also serve as a surrogate to represent the molecular structure for use in kinetic studies.

  13. Investigations of primary and secondary amine carbamate stability by 1H NMR spectroscopy for post combustion capture of carbon dioxide

    Highlights: ► Carbamate stability constants of series of amines have been measured at (288 to 318) K. ► Standard molar enthalpies and entropies have been determined by van’t Hoff analyses. ► A ΔHmo-ΔSmo plot for carbamate formation gives a linear relationship. ► This relationship provides a guide for the selection of amines for PCC applications. ► Stereochemical effects and intramolecular H-bonding affect carbamate formation. - Abstract: Carbamate formation is one of the major chemical reactions that can occur in solution in the capture of CO2 by amine-based solvents, and carbamate formation makes a significant enthalpy contribution to the absorption-desorption of CO2 that occurs in the absorber/stripper columns of the PCC process. Consequently, the formation of carbamates of selected series of primary and secondary amines over the temperature range (288 to 318) K has been investigated by equilibrium 1H NMR studies, and the stability constants (K9) for the equilibrium: RNH2+HCO3-⇄K9RNHCOO-+H2O are reported. van’t Hoff analyses have resulted in standard molar enthalpies, ΔHmo, and entropies, ΔSmo, of carbamate formation. A ΔHmo-ΔSmo plot generates a linear correlation for carbamate formation (providing a mean standard molar free energy, ΔGmo, for carbamate formation of about −7 kJ · mol−1), and this relationship helps provide a guide to the selection of an amine(s) solvent for CO2 capture, in terms of enthalpy considerations. A linear ΔHmo-ΔSmo plot also occurs for carbamate protonation. The formation of the carbamates has been correlated with systematic changes in composition and structure, and steric effects have been identified by comparing molecular geometries obtained using density functional B3LYP/6-311++G(d,p) calculations. Trends in steric effects have been identified in the series of compounds monoethanolamine (MEA), 1-amino-2-propanol, 2-amino-1-propanol (AP) and 2-amino-2-methyl-1-propanol (AMP). In the case of 2

  14. 1H and 23Na MAS NMR spectroscopy of cationic species in CO2 selective alkaline earth metal porous silicoaluminophosphates prepared via liquid and solid state ion exchange

    The location of extraframework cations in Sr2+ and Ba2+ ion-exchanged SAPO-34 was estimated by means of 1H and 23Na MAS NMR spectroscopy and spectral deconvolution. Incorporation of the alkaline earth metal cations onto the SAPO framework was achieved via liquid state ion exchange, coupled partial detemplation/solid-state ion exchange, and combination of both techniques. MAS NMR revealed that the level of ion exchange was limited by the presence of protons and sodium cations near hexagonal prisms (site SI), which are relatively difficult to exchange with the alkaline earth metal due to steric and charge repulsion criteria. In addition, the presence of ammonium cations in the supercages facilitated the exchange of otherwise tenacious hydrogen as corroborated by unit cell compositional data as well as enhanced CO2 adsorption at low partial pressures. The extraframework ammonium species were produced from partial detemplation of the structure-directing agent employed for the SAPO-34 synthesis, tetraethylammonium. - Graphical abstract: MAS NMR was used to elucidate the position the cationic species in alkaline earth metal exchanged silicoaluminophosphates. These species played a significant role during the ion exchange process and, therefore, the materials ultimate CO2 adsorption performance. Highlights: ► Location of extraframework Sr2+ or Ba2+ cations was estimated by means of 1H and 23Na MAS NMR. ► Level of Sr2+ or Ba2+ ion exchange was limited by the presence of protons and sodium cations. ► Presence of ammonium cations in the supercages facilitated the exchange. ► Sr2+ and Ba2+ ion exchanged SAPOs are outstanding CO2 adsorbents.

  15. Evidence for a dipolar-coupled AM system in carnosine in human calf muscle from in vivo 1H NMR spectroscopy

    Schröder, Leif; Bachert, Peter

    2003-10-01

    Spin systems with residual dipolar couplings such as creatine, taurine, and lactate in skeletal muscle tissue exhibit first-order spectra in in vivo 1H NMR spectroscopy at 1.5 T because the coupled protons are represented by (nearly) symmetrized eigenfunctions. The imidazole ring protons (H2, H4) of carnosine are suspected to form also a coupled system. The ring's stiffness could enable a connectivity between these anisochronous protons with the consequence of second-order spectra at low field strength. Our purpose was to study whether this deviation from the Paschen-Back condition can be used to detect the H2-H4 coupling in localized 1D 1H NMR spectra obtained at 1.5 T (64 MHz) from the human calf in a conventional whole-body scanner. As for the hydrogen hyperfine interaction, a Breit-Rabi equation was derived to describe the transition from Zeeman to Paschen-Back regime for two dipolar-coupled protons. The ratio of the measurable coupling strength ( Sk) and the difference in resonance frequencies of the coupled spins (Δ ω) induces quantum-state mixing of various degree upon definition of an appropriate eigenbase of the coupled spin system. The corresponding Clebsch-Gordan coefficients manifest in characteristic energy corrections in the Breit-Rabi formula. These additional terms were used to define an asymmetry parameter of the line positions as a function of Sk and Δ ω. The observed frequency shifts of the resonances were found to be consistent with this parameter within the accuracy achievable in in vivo NMR spectroscopy. Thus it was possible to identify the origin of satellite peaks of H2, H4 and to describe this so far not investigated type of residual dipolar coupling in vivo.

  16. NMR spectroscopy

    The book reviews the applications of NMR-spectroscopy in medicine and biology. The first chapter of about 40 pages summarizes the history of development and explains the chemical and physical fundamentals of this new and non-invasive method in an easily comprehensible manner. The other chapters summarize diagnostic results obtained with this method in organs and tissues, so that the reader will find a systematic overview of the available findings obtained in the various organ systems. It must be noted, however, that ongoing research work and new insight quite naturally will necessitate corrections to be done, as is the case here with some biochemical interpretations which would need adjustment to latest research results. NMR-spectroscopy is able to measure very fine energy differences on the molecular level, and thus offers insight into metabolic processes, with the advantage that there is no need of applying ionizing radiation in order to qualitatively or quantitatively analyse the metabolic processes in the various organ systems. (orig./DG) With 40 figs., 4 tabs

  17. Study of the contact charge transfer behavior between cryptophanes (A and E) and fullerene by absorption, fluorescence and {sup 1}H NMR spectroscopy

    Zhang Caihong; Shen Weili; Fan Ruying; Zhang Guomei; Shangguan Lingzhi; Chao Jianbin; Shuang Shaomin [Research Center of Environmental Science and Engineering, School of Chemistry and Chemical Engineering, Shanxi University, Taiyuan 030006 (China); Dong Chuan, E-mail: dc@sxu.edu.cn [Research Center of Environmental Science and Engineering, School of Chemistry and Chemical Engineering, Shanxi University, Taiyuan 030006 (China); Choi, Martin M.F., E-mail: mfchoi@hkbu.edu.hk [Department of Chemistry, Hong Kong Baptist University, Kowloon Tong (Hong Kong)

    2009-09-14

    A group of novel cage-like compounds cryptophanes A and E were synthesized from vanillin by a three-step method. The intermolecular interaction between cryptophanes (A and E) and fullerene (C{sub 60}) was investigated in detail by absorption, fluorescence and {sup 1}H NMR spectroscopy. The absorption of C{sub 60} at 410-650 nm decreased in the presence of cryptophanes A or E. The decrease in absorption intensity was proportional to the concentration of cryptophanes A or E. On the other hand, the fluorescence intensity of cryptophanes A or E decreased and the emission maxima were blue-shifted with the increase in C{sub 60} concentration. These results suggest that contact charge transfer (CCT) complexes can be formed from C{sub 60} with cryptophanes A or E. In addition, the electrochemical behavior of cryptophanes (A and E) and C{sub 60} was studied by cyclic voltammetry. The redox currents of cryptophanes (A and E) decreased and the peak potentials were shifted on addition of C{sub 60}. The changes in the chemical shifts ({Delta}{delta}) of aromatic protons of cryptophanes (A and E) in their NMR spectra further support that CCT complexes were formed with cryptophanes as the electron donors and C{sub 60} as the electron acceptor.

  18. 1H NMR in a-Si

    Carlos, W. E.; Taylor, P. C.

    1982-10-01

    Results of pulsed NMR studies of hydrogen in a-Si: H prepared at several laboratories by glow discharge of silane are presented. The origins of the two 1H NMR lines seen in almost all samples of a-Si: H are discussed. Solid-echo measurements are presented which indicate that these two components are due to spatially isolated groups of protons. We attribute the narrow line to protons slightly clustered in the bulk of the material and the broad line to protons distributed on internal surfaces. The spin-lattice relaxation time shows a minimum at T~30 K which is interpreted as due to relaxation via spin diffusion to a small number of H2 molecules acting as relaxation centers. Annealing results suggest that all the hydrogen molecules are trapped in very similar sites.

  19. Exploration of non-spinning ^1H NMR Spectroscopy as a Tool for Determination and Monitoring of Gas Hydrate Formation and Dissociation Processes

    Henrichsen, Magnus Rossmann

    2015-01-01

    Natural gas hydrates provide both a flow- assurance hazard and a potential fossil fuel source. In order to face the challenges presented by these scenarios, a greater understanding of the properties of hydrates in a range of environments is required. NMR spectroscopy provides a powerful tool for investigation of such properties; however, most previous studies have involved use of either deuterated components, ^13C NMR, magic angle spinning or a combination of these. Proton NMR of static natur...

  20. Application of High-Resolution 1H MAS NMR Spectroscopy to the Analysis of Intact Bones from Mice Exposed to Gamma Radiation

    Zhang, QiBin; Hu, Jian Zhi; Rommereim, Donald N.; Murphy, Mark K; Phipps, Richard P.; HUSO, DAVID L.; Dicello, John F

    2009-01-01

    Herein we demonstrate that high-resolution magic angle spinning (MAS) 1H NMR can be used to profile the pathology of bone marrow rapidly and with minimal sample preparation. The spectral resolution obtained allows several metabolites to be analyzed quantitatively. The level of NMR-detectable metabolites in the epiphysis + metaphysis sections of mouse femur were significantly higher than that observed in the diaphysis of the same femur. The major metabolite damage to bone marrow resulting from...

  1. High-resolution magic angle spinning (1)H NMR spectroscopy of metabolic changes in rabbit lens after treatment with dexamethasone combined with UVB exposure

    Seather, O.; Risa, O.; Čejková, Jitka; Krane, J.; Midelfart, A.

    2004-01-01

    Roč. 242, - (2004), s. 1000-1007. ISSN 0721-832X R&D Projects: GA ČR GA304/03/0419 Institutional research plan: CEZ:AV0Z5008914 Keywords : HR-MAS 1H NMR Subject RIV: FF - HEENT, Dentistry Impact factor: 1.513, year: 2004

  2. Secondary structure in solution of two anti-HIV-1 hammerhead ribozymes as investigated by two-dimensional 1H 500 MHz NMR spectroscopy in water

    Sarma, R. H.; Sarma, M. H.; Rein, R.; Shibata, M.; Setlik, R. S.; Ornstein, R. L.; Kazim, A. L.; Cairo, A.; Tomasi, T. B.

    1995-01-01

    Two hammerhead chimeric RNA/DNA ribozymes (HRz) were synthesized in pure form. Both were 30 nucleotides long, and the sequences were such that they could be targeted to cleave the HIV-1 gag RNA. Named HRz-W and HRz-M, the former had its invariable core region conserved, the latter had a uridine in the invariable region replaced by a guanine. Their secodary structures were determined by 2D NOESY 1H 500 MHz NMR spectroscopy in 90% water and 10% D2(0), following the imino protons. The data show that both HRz-M and HRz-W form identical secondary structures with stem regions consisting of continuous stacks of AT and GT pairs. An energy minimized computer model of this stem region is provided. The results suggest that the loss of catalytic activity that is known to result when an invariant core residue is replaced is not related to the secondary structure of the ribozymes in the absence of substrate.

  3. Hepatic lipid profiling of deer mice fed ethanol using {sup 1}H and {sup 31}P NMR spectroscopy: A dose-dependent subchronic study

    Fernando, Harshica; Bhopale, Kamlesh K.; Boor, Paul J.; Ansari, G.A. Shakeel; Kaphalia, Bhupendra S., E-mail: bkaphali@utmb.edu

    2012-11-01

    Chronic alcohol abuse is a 2nd major cause of liver disease resulting in significant morbidity and mortality. Alcoholic liver disease (ALD) is characterized by a wide spectrum of pathologies starting from fat accumulation (steatosis) in early reversible stage to inflammation with or without fibrosis and cirrhosis in later irreversible stages. Previously, we reported significant steatosis in the livers of hepatic alcohol dehydrogenase (ADH)-deficient (ADH{sup −}) vs. hepatic ADH-normal (ADH{sup +}) deer mice fed 4% ethanol daily for 2 months [Bhopale et al., 2006, Alcohol 39, 179–188]. However, ADH{sup −} deer mice fed 4% ethanol also showed a significant mortality. Therefore, a dose-dependent study was conducted to understand the mechanism and identify lipid(s) involved in the development of ethanol-induced fatty liver. ADH{sup −} and ADH{sup +} deer mice fed 1, 2 or 3.5% ethanol daily for 2 months and fatty infiltration in the livers were evaluated by histology and by measuring dry weights of extracted lipids. Lipid metabolomic changes in extracted lipids were determined by proton ({sup 1}H) and {sup 31}phosphorus ({sup 31}P) nuclear magnetic resonance (NMR) spectroscopy. The NMR data was analyzed by hierarchical clustering (HC) and principle component analysis (PCA) for pattern recognition. Extensive vacuolization by histology and significantly increased dry weights of total lipids found only in the livers of ADH{sup −} deer mice fed 3.5% ethanol vs. pair-fed controls suggest a dose-dependent formation of fatty liver in ADH{sup −} deer mouse model. Analysis of NMR data of ADH{sup −} deer mice fed 3.5% ethanol vs. pair-fed controls shows increases for total cholesterol, esterified cholesterol, fatty acid methyl esters (FAMEs), triacylglycerides and unsaturation, and decreases for free cholesterol, phospholipids and allylic and diallylic protons. Certain classes of neutral lipids (cholesterol esters, fatty acyl chain (-COCH{sub 2}-) and FAMEs) were

  4. Hepatic lipid profiling of deer mice fed ethanol using 1H and 31P NMR spectroscopy: A dose-dependent subchronic study

    Chronic alcohol abuse is a 2nd major cause of liver disease resulting in significant morbidity and mortality. Alcoholic liver disease (ALD) is characterized by a wide spectrum of pathologies starting from fat accumulation (steatosis) in early reversible stage to inflammation with or without fibrosis and cirrhosis in later irreversible stages. Previously, we reported significant steatosis in the livers of hepatic alcohol dehydrogenase (ADH)-deficient (ADH−) vs. hepatic ADH-normal (ADH+) deer mice fed 4% ethanol daily for 2 months [Bhopale et al., 2006, Alcohol 39, 179–188]. However, ADH− deer mice fed 4% ethanol also showed a significant mortality. Therefore, a dose-dependent study was conducted to understand the mechanism and identify lipid(s) involved in the development of ethanol-induced fatty liver. ADH− and ADH+ deer mice fed 1, 2 or 3.5% ethanol daily for 2 months and fatty infiltration in the livers were evaluated by histology and by measuring dry weights of extracted lipids. Lipid metabolomic changes in extracted lipids were determined by proton (1H) and 31phosphorus (31P) nuclear magnetic resonance (NMR) spectroscopy. The NMR data was analyzed by hierarchical clustering (HC) and principle component analysis (PCA) for pattern recognition. Extensive vacuolization by histology and significantly increased dry weights of total lipids found only in the livers of ADH− deer mice fed 3.5% ethanol vs. pair-fed controls suggest a dose-dependent formation of fatty liver in ADH− deer mouse model. Analysis of NMR data of ADH− deer mice fed 3.5% ethanol vs. pair-fed controls shows increases for total cholesterol, esterified cholesterol, fatty acid methyl esters (FAMEs), triacylglycerides and unsaturation, and decreases for free cholesterol, phospholipids and allylic and diallylic protons. Certain classes of neutral lipids (cholesterol esters, fatty acyl chain (-COCH2-) and FAMEs) were also mildly increased in ADH− deer mice fed 1 or 2% ethanol. Only small

  5. Urine Metabolomics by 1H-NMR Spectroscopy Indicates Associations between Serum 3,5-T2 Concentrations and Intermediary Metabolism in Euthyroid Humans

    Pietzner, Maik; Homuth, Georg; Budde, Kathrin; Lehmphul, Ina; Völker, Uwe; Völzke, Henry; Nauck, Matthias; Köhrle, Josef; Friedrich, Nele

    2015-01-01

    Context 3,5-Diiodo-L-thyronine (3,5-T2) is a thyroid hormone metabolite which exhibited versatile effects in rodent models, including the prevention of insulin resistance or hepatic steatosis typically forced by a high-fat diet. With respect to euthyroid humans, we recently observed a putative link between serum 3,5-T2 and glucose but not lipid metabolism. Objective The aim of the present study was to widely screen the urine metabolome for associations with serum 3,5-T2 concentrations in healthy individuals. Study Design and Methods Urine metabolites of 715 euthyroid participants of the population-based Study of Health in Pomerania (SHIP-TREND) were analyzed by 1H-NMR spectroscopy. Multinomial logistic and multivariate linear regression models were used to detect associations between urine metabolites and serum 3,5-T2 concentrations. Results Serum 3,5-T2 concentrations were positively associated with urinary levels of trigonelline, pyroglutamate, acetone and hippurate. In detail, the odds for intermediate or suppressed serum 3,5-T2 concentrations doubled owing to a 1-standard deviation (SD) decrease in urine trigonelline levels, or increased by 29-50% in relation to a 1-SD decrease in urine pyroglutamate, acetone and hippurate levels. Conclusion Our findings in humans confirmed the metabolic effects of circulating 3,5-T2 on glucose and lipid metabolism, oxidative stress and enhanced drug metabolism as postulated before based on interventional pharmacological studies in rodents. Of note, 3,5-T2 exhibited a unique urinary metabolic profile distinct from previously published results for the classical thyroid hormones. PMID:26601079

  6. 1H NMR spectroscopic identification of a glue sniffing biomarker.

    Kwon, Bobae; Kim, Siwon; Kim, Sosun; Lee, Dong-Kye; Park, Yu-Jin; Kim, Myung-Duck; Lee, Jae-Shin; Kim, Suhkmann

    2011-06-15

    Organic solvent abuse typically involves sniffing organic solvents to experience the mind-altering conditions they induce. In Republic of Korea, organic solvent abuse is a serious social problem, especially among teenagers. Several studies have addressed the effects of organic solvent abuse on mind and body, but there are no simple methods by which such abuse can be positively identified. In this report, we describe a method for analyzing toluene metabolites (toluene is the main ingredient of glue) in glue-sniffers' urine using (1)H NMR spectroscopy. Toluene is a commonly used solvent in the rubber, paint, plastics, leather, printing, and chemical industries. Inhaled toluene is metabolized to hippuric acid in the liver and excreted in the urine. Hippuric acid is known as a good biomarker for biological monitoring of toluene exposure. We have scanned hippuric acid and other toluene metabolites by NMR spectroscopy and performed statistical multivariate analysis of the data. Based on this analysis, we sought to determine parameters by which glue-sniffing (toluene inhalation) behavior may be verified. We also demonstrate the use of a pattern recognition method for accurate and efficient analysis of NMR data. In comparison to conventional methods, such as mass spectroscopy coupled with liquid chromatography or gas chromatography, nuclear magnetic resonance spectroscopy has several advantages, including simple sample preparation, non-destructive sampling, accuracy, short acquisition time, and reproducibility in the determination of urinary hippuric acid. PMID:21316881

  7. 1H HRMAS NMR spectroscopy and chemometrics for evaluation of metabolic changes in citrus sinensis Caused by Xanthomonas axonopodis pv. citri

    Xanthomonas axonopodis (Xac) bacterium causes one of the most feared and untreatable diseases in citriculture: citrus canker. To understand the response mechanisms of orange trees when attacked by Xac, leaves and fruits of Citrus sinensis were directly evaluated by HRMAS NMR (high resolution magic angle spinning nuclear magnetic resonance) spectroscopy. This technique allows the analysis of samples without laborious pre-treatments and also allows access to important information about chemical composition of samples. The orange tree leaves and fruit peels investigated in this study demonstrated the biochemical changes caused by Xac. Aided by chemometric analysis, the HRMAS NMR results show relevant changes in amino acids, carbohydrates, organic acids and terpenoids content. (author)

  8. Binding of iodide to Arthromyces ramosus peroxidase investigated with X-ray crystallographic analysis, 1H and 127I NMR spectroscopy, and steady-state kinetics

    The site and characteristics of iodide binding to Arthromyces ramosus peroxidase were examined by x-ray crystallographic analysis, 1H and 127I NMR, and kinetic studies. X-ray analysis of an A. ramosus peroxidase crystal soaked in a KI solution at pH 5.5 showed that a single iodide ion is located at the entrance of the access channel to the distal side of the heme and lies between the two peptide segments, Phe90-Pro91-Ala92 and Ser151-Leu152-Ile153, 12.8 angstrom from the heme iron. The distances between the iodide ion and heme peripheral methyl groups were all more than 10 angstrom. The findings agree with the results obtained with 1H NMR in which the chemical shift and intensity of the methyl groups in the hyperfine shift region of A. ramosus peroxidase were hardly affected by the addition of iodide, unlike the case of horseradish peroxidase. Moreover, 127I NMR and steady-state kinetics showed that the binding of iodide depends on protonation of an amino acid residue with a PKa of about 5.3, which presumably is the distal histidine (His56), 7.8 angstrom away from the iodide ion. The mechanism of electron transfer from the iodide ion to the heme iron is discussed on the basis of these findings

  9. Metabonomic profiling of serum and urine by (1H NMR-based spectroscopy discriminates patients with chronic obstructive pulmonary disease and healthy individuals.

    Lingling Wang

    Full Text Available Chronic obstructive pulmonary disease (COPD has seriously impacted the health of individuals and populations. In this study, proton nuclear magnetic resonance ((1H NMR-based metabonomics combined with multivariate pattern recognition analysis was applied to investigate the metabolic signatures of patients with COPD. Serum and urine samples were collected from COPD patients (n = 32 and healthy controls (n = 21, respectively. Samples were analyzed by high resolution (1H NMR (600 MHz, and the obtained spectral profiles were then subjected to multivariate data analysis. Consistent metabolic differences have been found in serum as well as in urine samples from COPD patients and healthy controls. Compared to healthy controls, COPD patients displayed decreased lipoprotein and amino acids, including branched-chain amino acids (BCAAs, and increased glycerolphosphocholine in serum. Moreover, metabolic differences in urine were more significant than in serum. Decreased urinary 1-methylnicotinamide, creatinine and lactate have been discovered in COPD patients in comparison with healthy controls. Conversely, acetate, ketone bodies, carnosine, m-hydroxyphenylacetate, phenylacetyglycine, pyruvate and α-ketoglutarate exhibited enhanced expression levels in COPD patients relative to healthy subjects. Our results illustrate the potential application of NMR-based metabonomics in early diagnosis and understanding the mechanisms of COPD.

  10. Effect of organochlorine pesticides exposure on the maize root metabolome assessed using high-resolution magic-angle spinning (1)H NMR spectroscopy.

    Blondel, Claire; Khelalfa, Farid; Reynaud, Stéphane; Fauvelle, Florence; Raveton, Muriel

    2016-07-01

    (1)H-HRMAS NMR-based metabolomics was used to better understand the toxic effects on maize root tips of organochlorine pesticides (OCPs), namely lindane (γHCH) and chlordecone (CLD). Maize seedlings were exposed to 2.5 μM γHCH (mimicking basic environmental contaminations) for 7 days and compared to 2.5 μM CLD and 25 μM γHCH for 7 days (mimicking hot spot contaminations). The (1)H-HRMAS NMR-based metabolomic profiles provided details of the changes in carbohydrates, amino acids, tricarboxylic acid (TCA) cycle intermediates and fatty acids with a significant separation between the control and OCP-exposed root tips. First of all, alterations in the balance between glycolysis/gluconeogenesis were observed with sucrose depletion and with dose-dependent fluctuations in glucose content. Secondly, observations indicated that OCPs might inactivate the TCA cycle, with sizeable succinate and fumarate depletion. Thirdly, disturbances in the amino acid composition (GABA, glutamine/glutamate, asparagine, isoleucine) reflected a new distribution of internal nitrogen compounds under OCP stress. Finally, OCP exposure caused an increase in fatty acid content, concomitant with a marked rise in oxidized fatty acids which could indicate failures in cell integrity and vitality. Moreover, the accumulation of asparagine and oxidized fatty acids with the induction of LOX3 transcription levels under OCP exposure highlighted an induction of protein and lipid catabolism. The overall data indicated that the effect of OCPs on primary metabolism could have broader physiological consequences on root development. Therefore, (1)H-HRMAS NMR metabolomics is a sensitive tool for understanding molecular disturbances under OCP exposure and can be used to perform a rapid assessment of phytotoxicity. PMID:27131813

  11. Conformational and Coordination Equilibria on DOTA Complexes of Lanthanide Metal Ions in Aqueous Solution Studied by 1H-NMR Spectroscopy

    Aime, Silvio; Botta, Mauro; Fasano, Mauro; Marques, M. Paula M.; Geraldes, Carlos F. G. C.; Pubanz, Dirk; Merbach, André E.

    1997-01-01

    A variable-temperature, -pressure, and -ionic strength 1H NMR study of the DOTA complexes of different trivalent cations (Sc, Y, La, Ce → Lu) (DOTA = 1,4,7,10-tetraaza-1,4,7,10-tetrakis(carboxymethyl)cyclododecane) yielded data that are in contradiction with the hitherto used model of only two enantiomeric pairs of diastereoisomers that differ in the ligand conformations. A two-isomer equilibrium cannot explain the newly observed apparent reversal of the isomer ratio at the end of the series....

  12. Metabolomic profiling of the phytomedicinal constituents of Carica papaya L. leaves and seeds by 1H NMR spectroscopy and multivariate statistical analysis.

    Gogna, Navdeep; Hamid, Neda; Dorai, Kavita

    2015-11-10

    Extracts from the Carica papaya L. plant are widely reported to contain metabolites with antibacterial, antioxidant and anticancer activity. This study aims to analyze the metabolic profiles of papaya leaves and seeds in order to gain insights into their phytomedicinal constituents. We performed metabolite fingerprinting using 1D and 2D 1H NMR experiments and used multivariate statistical analysis to identify those plant parts that contain the most concentrations of metabolites of phytomedicinal value. Secondary metabolites such as phenyl propanoids, including flavonoids, were found in greater concentrations in the leaves as compared to the seeds. UPLC-ESI-MS verified the presence of significant metabolites in the papaya extracts suggested by the NMR analysis. Interestingly, the concentration of eleven secondary metabolites namely caffeic, cinnamic, chlorogenic, quinic, coumaric, vanillic, and protocatechuic acids, naringenin, hesperidin, rutin, and kaempferol, were higher in young as compared to old papaya leaves. The results of the NMR analysis were corroborated by estimating the total phenolic and flavonoid content of the extracts. Estimation of antioxidant activity in leaves and seed extracts by DPPH and ABTS in-vitro assays and antioxidant capacity in C2C12 cell line also showed that papaya extracts exhibit high antioxidant activity. PMID:26163870

  13. {sup 1}H MR spectroscopy in epilepsy

    Hajek, Milan [MR Unit, Department of Diagnostic and Interventional Radiology, Institute for Clinical and Experimental Medicine, Videnska 1958/9, 140 21 Prague (Czech Republic)], E-mail: miha@medicon.cz; Dezortova, Monika [MR Unit, Department of Diagnostic and Interventional Radiology, Institute for Clinical and Experimental Medicine, Videnska 1958/9, 140 21 Prague (Czech Republic)], E-mail: mode@medicon.cz; Krsek, Pavel [Department of Pediatric Neurology, Charles University, Second Medical School, Motol Hospital, V Uvalu 84, 150 06 Prague 5 (Czech Republic)], E-mail: pavel.krsek@post.cz

    2008-08-15

    The introduction to the application of {sup 1}H MR spectroscopy for clinical and research studies of mesial temporal and extratemporal epilepsies is done. The techniques of single voxel and spectroscopic imaging are discussed and the analysis of {sup 1}H MR spectra together with basic metabolic descriptions is presented.

  14. 1H MR spectroscopy in epilepsy

    The introduction to the application of 1H MR spectroscopy for clinical and research studies of mesial temporal and extratemporal epilepsies is done. The techniques of single voxel and spectroscopic imaging are discussed and the analysis of 1H MR spectra together with basic metabolic descriptions is presented

  15. Site-directed mutagenesis and 1H NMR spectroscopy of an interdomain segment in the pyruvate dehydrogenase multienzyme complex of Escherichia coli

    Deletion of two of the three homologous lipoyl domains that form the N-terminal half of each dihydrolipoamide acetyltransferase (E2p) polypeptide chain of the Escherichia coli pyruvate dehydrogenase complex can be achieved by in vitro deletion in the structural gene aceF. A site-directed mutagenesis of this shortened aceF gene was carried out to replace the glutamine residue at position 291 (wild-type numbering) with a histidine residue. Residue 291 is near the middle of a long segment (about 30 amino acid residues) of polypeptide chain, rich in alanine, proline, and charged amino acids, that links the remaining lipoyl domain to the dihydrolipoamide dehydrogenase (E3) binding domain in the E2p chain. A fully active enzyme complex was still assembled, and despite the enormous size of the particle, sharp resonances attributable to the single new histidine residue per E2p chain could be detected in the 400-MHz 1H NMR spectrum of the complex. The sharpness of these resonances, their chemical shifts (7.94 and 7.05 ppm), and the apparent pK/sub a/ (6.4) of the side chain were all consistent with this histidine residue being exposed to solvent in a conformationally flexible region of the E2p polypeptide chain. These experiments provide direct proof for the conformational flexibility of this region of polypeptide chain, which is though to play an important part in the movement of the lipoyl domain required for active site coupling in the enzyme complex. The major sharp resonance (at l.39 ppm) in the 400-MHz 1H NMR spectrum of the mutated complex, was somewhat smaller than expected, suggesting that the insertion of the histidine residue at position 291 had diminished the flexibility of some at least of the alanine residues in this segment of polypeptide chain

  16. Assessment of a 1H high-resolution magic angle spinning NMR spectroscopy procedure for free sugars quantification in intact plant tissue.

    Delgado-Goñi, Teresa; Campo, Sonia; Martín-Sitjar, Juana; Cabañas, Miquel E; San Segundo, Blanca; Arús, Carles

    2013-08-01

    In most plants, sucrose is the primary product of photosynthesis, the transport form of assimilated carbon, and also one of the main factors determining sweetness in fresh fruits. Traditional methods for sugar quantification (mainly sucrose, glucose and fructose) require obtaining crude plant extracts, which sometimes involve substantial sample manipulation, making the process time-consuming and increasing the risk of sample degradation. Here, we describe and validate a fast method to determine sugar content in intact plant tissue by using high-resolution magic angle spinning nuclear magnetic resonance spectroscopy (HR-MAS NMR). The HR-MAS NMR method was used for quantifying sucrose, glucose and fructose in mesocarp tissues from melon fruits (Cucumis melo var. reticulatus and Cucumis melo var. cantalupensis). The resulting sugar content varied among individual melons, ranging from 1.4 to 7.3 g of sucrose, 0.4-2.5 g of glucose; and 0.73-2.83 g of fructose (values per 100 g fw). These values were in agreement with those described in the literature for melon fruit tissue, and no significant differences were found when comparing them with those obtained using the traditional, enzymatic procedure, on melon tissue extracts. The HR-MAS NMR method offers a fast (usually <30 min) and sensitive method for sugar quantification in intact plant tissues, it requires a small amount of tissue (typically 50 mg fw) and avoids the interferences and risks associated with obtaining plant extracts. Furthermore, this method might also allow the quantification of additional metabolites detectable in the plant tissue NMR spectrum. PMID:23824526

  17. Mechanism of the bisphosphatase reaction of 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase probed by (1)H-(15)N NMR spectroscopy.

    Okar, D A; Live, D H; Devany, M H; Lange, A J

    2000-08-15

    The histidines in the bisphosphatase domain of rat liver 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase were labeled with (15)N, both specifically at N1' and globally, for use in heteronuclear single quantum correlation (HSQC) NMR spectroscopic analyses. The histidine-associated (15)N resonances were assigned by correlation to the C2' protons which had been assigned previously [Okar et al., Biochemistry 38, 1999, 4471-79]. Acquisition of the (1)H-(15)N HSQC from a phosphate-free sample demonstrated that the existence of His-258 in the rare N1' tautomeric state is dependent upon occupation of the phosphate binding site filled by the O2 phosphate of the substrate, fructose-2,6-bisphosphate, and subsequently, the phosphohistidine intermediate. The phosphohistidine intermediate is characterized by two hydrogen bonds involving the catalytic histidines, His-258 and His-392, which are directly observed at the N1' positions of the imidazole rings. The N1' of phospho-His-258 is protonated ((1)H chemical shift, 14.0 ppm) and hydrogen bonded to the backbone carbonyl of Gly-259. The N1' of cationic His-392 is hydrogen bonded ((1)H chemical shift, 13.5 ppm) to the phosphoryl moiety of the phosphohistidine. The existence of a protonated phospho-His-258 intermediate and the observation of a fairly strong hydrogen bond to the same phosphohistidine implies that hydrolysis of the covalent intermediate proceeds without any requirement for an "activated" water. Using the labeled histidines as probes of the catalytic site mutation of Glu-327 to alanine revealed that, in addition to its function as the proton donor to fructose-6-phosphate during formation of the transient phosphohistidine intermediate at the N3' of His-258, this residue has a significant role in maintaining the structural integrity of the catalytic site. The (1)H-(15)N HSQC data also provide clear evidence that despite being a surface residue, His-446 has a very acidic pK(a), much less than 6.0. On the basis of

  18. Hochfeld 1H-NMR-Mikroskopie zur biophysikalischen Grundlagenforschung

    Haddad, Daniel

    2005-01-01

    Dank der mit modernen NMR-Spektrometern (Kernspintomographen) routinemäßig realisierbaren isotropen räumlichen Auflösungen von wenigen Mikrometern, ergeben sich für die 1H NMR-Mikroskopie zahlreiche neue Anwendungsgebiete. Allerdings sind die Möglichkeiten und Grenzen der NMR-Mikroskopie bezüglich ihrer praktischen Anwendbarkeit bisher nur wenig untersucht worden. Die vorliegende Arbeit ist im Bereich der biophysikalischen Grundlagenforschung angesiedelt und soll die praktische Anwendbarkeit ...

  19. Applying 1H NMR Spectroscopy to Detect Changes in the Urinary Metabolite Levels of Chinese Half-Pipe Snowboarders after Different Exercises

    Fuqiu Wang

    2015-01-01

    Full Text Available Monitoring physical training is important for the health and performance of athletes, and real-time assessment of fatigue is crucial to improve training efficiency. The relationship between key biomarkers and exercise has been reported. The aim of this study was to determine the effects of different levels of training exercises on the urine metabolome. 1H NMR-based metabolomics analysis was performed on urine samples from half-pipe snowboarders, and spectral profiles were subjected to PCA and PLS-DA. Our results show that metabolic profiles varied during different stages of exercises. Lactate, alanine, trimethylamine, malonate, taurine, and glycine levels decreased while TMAO and phenylalanine levels increased in the stage with higher amount and intensity of exercise. Although the amount of exercise was reduced in subsequent stage, no significant variations of metabolic profile were found. Metabolic changes induced by training level were analyzed with related metabolic pathway. Studying metabolome changes can provide a better understanding of the physiology of athletes and could aid in adjusting training.

  20. Selective anion sensing by a tris-amide CTV derivative: 1H NMR titration, self-assembled monolayers, and impedance spectroscopy.

    Zhang, Sheng; Echegoyen, Luis

    2005-02-16

    A hydrogen-bond forming tris(amide) receptor based on cyclotriveratrylene (CTV) was prepared. Self-assembled monolayers (SAMs) of the receptor were formed on gold surfaces. Desorption experiments show a surface coverage of 2.26 x 10(-10) mol/cm(2). (1)H NMR and UV measurements confirm that the receptor exhibits the highest affinity for acetate ions among the anions studied. Electrochemical impedance was used to investigate anion sensing by the SAMs and proved to be an efficient and convenient technique for detecting anions in aqueous solutions. Upon binding acetate anions, the monolayer-modified gold electrodes show a drastic increase of the R(ct) values when Fe(CN)(6)(3-/4-) is used as the redox probe. When the probe was changed to a positively charged one, Ru(NH3)(6)(3+/2+), the R(ct) values decreased monotonically as the acetate concentration was increased, thus confirming the accumulation of negative surface charge upon anion binding. H(2)PO(4-) shows some interference when sensing AcO-. Other monovalent anions such as Cl-, Br-, NO3(-) and HSO4(-) do not bind to the CTV receptor either in solution or on the surfaces. PMID:15701037

  1. Identification of 2-[2-nitro-4-(trifluoromethyl)benzoyl]- cyclohexane-1,3-dione metabolites in urine of patients suffering from tyrosinemia type I with the use of 1H and 19F NMR spectroscopy.

    Szczeciński, Przemysław; Lamparska, Diana; Gryff-Keller, Adam; Gradowska, Wanda

    2008-01-01

    Organic extracts of six urine samples from children treated with nitisinone, a medicine against tyrosinemia type I, were investigated by (1)H and (19)F NMR spectroscopy. The presence of unchanged 2-[2-nitro-4-(trifluoromethyl)benzoyl]cyclohexane-1,3-dione (NTBC), 6-hydroxy-2-[2-nitro-4-(trifluoromethyl)benzoyl]cyclohexane-1,3-dione (NTBC-OH) and 2-nitro-4-trifluoromethylbenzoic acid (NTFA) as well as a few other unidentified compounds containing CF(3) group was documented. PMID:19039335

  2. Identification of 2-[2-nitro-4-(trifluoromethyl)benzoyl]-cyclohexane-1,3-dione metabolites in urine of patients suffering from tyrosinemia type I with the use of 1H and 19F NMR spectroscopy

    Organic extracts of six urine samples from children treated with nitisinone, a medicine against tyrosinemia type I, were investigated by 1H and 19F NMR spectroscopy. The presence of unchanged 2-[2-nitro-4-(trifluoromethyl)benzoyl]cyclohexane-1,3-dione (NTBC), 6-hydroxy-2-[2-nitro- 4-(trifluoromethyl)benzoyl]cyclohexane-1,3-dione (NTBC-OH) and 2-nitro-4-trifluoromethylbenzoic acid (NTFA) as well as a few other unidentified compounds containing CF3 group was documented. (authors)

  3. Synthesis and purification of 2-deoxy-2-[18F]fluoro-D-glucose and 2-deoxy-2-[18F]fluoro-D-mannose: characterization of products by 1H- and 19F-NMR spectroscopy

    A procedure has been developed that allows the separation 2-deoxy-2-[18F]fluoro-D-glucose from 2-deoxy-2-[18F]fluoro-D-mannose employing selectively optimized ion-moderated partition chromatography. Both compounds can be obtained with a >98% chemical and radiochemical purity in about one half-life of 18F. Both the α- and β-anomers of both sugars were completely characterized by high-resolution 1H- and 19F-NMR spectroscopy. Various convenient preparation methods for 2-deoxy-2-[18F]fluoro-D-glucose were compared. (author)

  4. Application of 1H and 23Na magic angle spinning NMR spectroscopy to define the HRBC up-taking of MRI contrast agents

    Calabi, Luisella; Paleari, Lino; Biondi, Luca; Linati, Laura; De Miranda, Mario; Ghelli, Stefano

    2003-09-01

    The up-take of Gd(III) complexes of BOPTA, DTPA, DOTA, EDTP, HPDO3A, and DOTP in HRBC has been evaluated by measuring the lanthanide induced shift (LIS) produced by the corresponding dysprosium complexes (DC) on the MAS-NMR resonances of water protons and free sodium ions. These complexes are important in their use as MRI contrast agents (MRI-CA) in diagnostics. 1H and 23Na MAS-NMR spectra of HRBC suspension, collected at 9.395 T, show only one signal due to extra- and intra-cellular water (or sodium). In MAS spectra, the presence of DC in a cellular compartment produces the LIS of only the nuclei (water proton or sodium) in that cellular compartment and this LIS can be related to the DC concentrations (by the experimental curves of LIS vs. DC concentrations) collected in the physiological solution. To obtain correct results about LIS, the use of MAS technique is mandatory, because it guarantees the only the nuclei staying in the same cellular compartment where the LC is present show the LIS. In all the cases considered, the addition of the DC to HRBC (100% hematocrit) produced a shift of only the extra-cellular water (or sodium) signal and the gradient of concentration ( GC) between extra- and intra-cellular compartments resulted greater than 100:1, when calculated by means of sodium signals. These high values of GC are direct proofs that none of the tested dysprosium complexes crosses the HRBC membrane. Since the DC are iso-structural to the gadolinium complexes the corresponding gadolinium ones (MRI-CA) do not cross the HRBC membrane and, consequently, they are not up-taken in HRBC. The GC values calculated by means of water proton signals resulted much lower than those obtained by sodium signals. This proves that the choice of the isotope is a crucial step in order to use this method in the best way. In fact, GC value depends on the lowest detectable LIS which, in turn, depends on the nature of the LC (lanthanide complex) and the observed isotopes.

  5. Laundering and Deinking Applications of 1H NMR Imaging

    Tutunjian, P. N.; Borchardt, J. K.; Prieto, N. E.; Raney, K. H.; Ferris, J. A.

    One-dimensional 1H NMR imaging techniques are used to visualize oil removal from fabrics and paper fibers immersed in aqueous solutions of nonionic detergents. The method provides a unique approach to the study of oil-removal kinetics in nonionic detergent systems where traditional optical techniques fail due to solution turbidity. The only requirement of the NMR experiment is the use of deuterated water in order to selectively image the hydrocarbon phase. Preliminary applications to laundering and paper deinking are discussed.

  6. {sup 1}H and {sup 23}Na MAS NMR spectroscopy of cationic species in CO{sub 2} selective alkaline earth metal porous silicoaluminophosphates prepared via liquid and solid state ion exchange

    Arevalo-Hidalgo, Ana G. [Department of Chemical Engineering, University of Puerto Rico-Mayagueez Campus, Mayagueez, PR 00681-9000 (Puerto Rico); Dugar, Sneha; Fu, Riqiang [National High Magnetic Field Laboratory, Florida State University, Tallahassee, FL 32310 (United States); Hernandez-Maldonado, Arturo J., E-mail: arturoj.hernandez@upr.edu [Department of Chemical Engineering, University of Puerto Rico-Mayagueez Campus, Mayagueez, PR 00681-9000 (Puerto Rico)

    2012-07-15

    The location of extraframework cations in Sr{sup 2+} and Ba{sup 2+} ion-exchanged SAPO-34 was estimated by means of {sup 1}H and {sup 23}Na MAS NMR spectroscopy and spectral deconvolution. Incorporation of the alkaline earth metal cations onto the SAPO framework was achieved via liquid state ion exchange, coupled partial detemplation/solid-state ion exchange, and combination of both techniques. MAS NMR revealed that the level of ion exchange was limited by the presence of protons and sodium cations near hexagonal prisms (site SI), which are relatively difficult to exchange with the alkaline earth metal due to steric and charge repulsion criteria. In addition, the presence of ammonium cations in the supercages facilitated the exchange of otherwise tenacious hydrogen as corroborated by unit cell compositional data as well as enhanced CO{sub 2} adsorption at low partial pressures. The extraframework ammonium species were produced from partial detemplation of the structure-directing agent employed for the SAPO-34 synthesis, tetraethylammonium. - Graphical abstract: MAS NMR was used to elucidate the position the cationic species in alkaline earth metal exchanged silicoaluminophosphates. These species played a significant role during the ion exchange process and, therefore, the materials ultimate CO{sub 2} adsorption performance. Highlights: Black-Right-Pointing-Pointer Location of extraframework Sr{sup 2+} or Ba{sup 2+} cations was estimated by means of {sup 1}H and {sup 23}Na MAS NMR. Black-Right-Pointing-Pointer Level of Sr{sup 2+} or Ba{sup 2+} ion exchange was limited by the presence of protons and sodium cations. Black-Right-Pointing-Pointer Presence of ammonium cations in the supercages facilitated the exchange. Black-Right-Pointing-Pointer Sr{sup 2+} and Ba{sup 2+} ion exchanged SAPOs are outstanding CO{sub 2} adsorbents.

  7. Dimethyl sulfone in human cerebrospinal fluid and blood plasma confirmed by one-dimensional (1)H and two-dimensional (1)H-(13)C NMR.

    Engelke, U.F.H.; Tangerman, A.; Willemsen, M.A.A.P.; Moskau, D.; Loss, S.; Mudd, S.H.; Wevers, R.A.

    2005-01-01

    (1)H-NMR spectroscopy at 500 MHz was used to confirm that a previously unidentified singlet resonance at 3.14 ppm in the spectra of cerebrospinal fluid and plasma samples corresponds to dimethyl sulfone (DMSO(2)). A triple resonance inverse cryogenic NMR probe, with pre-amplifier and the RF-coils co

  8. Applications of 1H-NMR to Biodiesel Research

    Biodiesel is an alternative diesel fuel derived from vegetable oils, animal fats, or used cooking oils. It is produced by reacting these materials with an alcohol in the presence of a catalyst to give the corresponding mono-alkyl esters. 1H-NMR is a routine analytical method that has been used for...

  9. Conformational Analysis of Indole Alkaloids Corynantheine and Dihydrocorynantheine by Dynamic 1H NMR Spectroscopy and Computational Methods: Steric Effects of Ethyl vs Vinyl Group

    Stærk, Dan; Norrby, Per-Ola; Jaroszewski, Jerzy W.

    2001-01-01

    (*) level) computational methods, the results of which were in good agreement with the H-1 NMR data. However, the calculations identified the rotamers as essentially isoenergetic, the experimental energy differences being to small to be reproduced exactly by the theory. Comparison of density-functional and...

  10. {sup 1}H and {sup 13}C NMR spectroscopy of 5-methyl-5H-indole-[2,3-b]quinoline; Spektroskopia {sup 1}H i {sup 13}C NMR 5-metylo-5H-indole-[2,3-b]chinoliny

    Kamienska-Trela, K.; Kania, L.; Kaczmarek, L. [Inst. Chemii Organicznej, Polska Akademia Nauk, Warsaw (Poland)

    1994-12-31

    {sup 1}H and {sup 13}C NMR spectra of 5-methyl-5H-indole quinoline have been measured in CDCl{sub 3} solution. The full assignation of resonant signals observed for this compound has been done. Also the chemical shifts {delta}({sup 1}H) and {delta}({sup 13}C) have been determined. That parameters as being tightly dependent on electronic density in molecule are very important also from the view point of biological activity of investigated compound. 3 refs, 1 fig., 1 tab.

  11. Using a Problem Solving-Cooperative Learning Approach to Improve Students' Skills for Interpreting [Superscript 1]H NMR Spectra of Unknown Compounds in an Organic Spectroscopy Course

    Angawi, Rihab F.

    2014-01-01

    To address third- and fourth-year chemistry students' difficulties with the challenge of interpreting [superscript 1]H NMR spectra, a problem solving-cooperative learning technique was incorporated in a Spectra of Organic Compounds course. Using this approach helped students deepen their understanding of the basics of [superscript 1]H NMR…

  12. 1H NMR determination of urinary betaine in patients with premature vascular disease and mild homocysteinemia.

    Lundberg, P; Dudman, N P; Kuchel, P W; Wilcken, D E

    1995-02-01

    Urinary N,N,N-trimethylglycine (betaine) and N,N-dimethylglycine (DMG) have been identified and quantified for clinical purposes by proton nuclear magnetic resonance (1H NMR) measurement in previous studies. We have assessed these procedures by using both one-dimensional (1-D) and 2-D NMR spectroscopy, together with pH titration of urinary extracts to help assign 1H NMR spectral peaks. The betaine calibration curve linearity was excellent (r = 0.997, P = 0.0001) over the concentration range 0.2-1.2 mmol/L, and CVs for replicate betaine analyses ranged from 7% (n = 10) at the lowest concentration to 1% (n = 9) at the highest. The detection limit for betaine was < 15 mumol/L. Urinary DMG concentrations were substantially lower than those of betaine. Urinary betaine and DMG concentrations measured by 1H NMR spectroscopy from 13 patients with premature vascular disease and 17 normal controls provided clinically pertinent data. We conclude that 1H NMR provides unique advantages as a research tool for determination of urinary betaine and DMG concentrations. PMID:7533065

  13. Comparative 1H NMR-based metabonomic analysis of HIV-1 sera

    1H NMR spectroscopy of sera from HIV-1 infected and uninfected individuals was performed on 300 and 600 MHz instruments. The resultant spectra were automatically data reduced to 90 and 180 integral segments of equal length. Analysis of variance identified significant differences between the sample groups, especially for the samples analyzed on 600 MHz and reduced to fewer segments. Linear discriminant analysis correctly classified 100% of the samples analyzed on the 300 MHz NMR (reduced to 180 segments); an increase in instrument sensitivity resulted in lower percentages of correctly classified samples. Multinomial logistic regression (MLR) resulted in 100% correct classification of all samples from both instruments. Thus 1H-NMR metabonomics on either instrument distinguishes HIV-positive individuals using or not using anti retroviral therapy, but the sensitivity of the instrument impacts on data reduction. Furthermore, MLR is a novel multivariate statistical technique for improved classification of biological data analyzed in NMR

  14. Comparative {sup 1}H NMR-based metabonomic analysis of HIV-1 sera

    Philippeos, C. [University of Johannesburg, Department of Biochemistry (South Africa); Steffens, F. E. [University of Pretoria, Department of Statistics (South Africa); Meyer, D. [University of Pretoria, Department of Biochemistry (South Africa)], E-mail: debra.meyer@up.ac.za

    2009-07-15

    {sup 1}H NMR spectroscopy of sera from HIV-1 infected and uninfected individuals was performed on 300 and 600 MHz instruments. The resultant spectra were automatically data reduced to 90 and 180 integral segments of equal length. Analysis of variance identified significant differences between the sample groups, especially for the samples analyzed on 600 MHz and reduced to fewer segments. Linear discriminant analysis correctly classified 100% of the samples analyzed on the 300 MHz NMR (reduced to 180 segments); an increase in instrument sensitivity resulted in lower percentages of correctly classified samples. Multinomial logistic regression (MLR) resulted in 100% correct classification of all samples from both instruments. Thus {sup 1}H-NMR metabonomics on either instrument distinguishes HIV-positive individuals using or not using anti retroviral therapy, but the sensitivity of the instrument impacts on data reduction. Furthermore, MLR is a novel multivariate statistical technique for improved classification of biological data analyzed in NMR.

  15. Rapid assessment of the illegal presence of 1,3-dimethylamylamine (DMAA) in sports nutrition and dietary supplements using 1H NMR spectroscopy.

    Monakhova, Yulia B; Ilse, Maren; Hengen, Julia; El-Atma, Oliver; Kuballa, Thomas; Kohl-Himmelseher, Matthias; Lachenmeier, Dirk W

    2014-09-01

    1,3-Dimethylamylamine (DMAA) is a stimulant that can be found in pre-workout sports nutrition and dietary supplements. This practice is illegal because DMAA is not a safe food ingredient but rather an unapproved medicinal compound due to its pharmacological action. In order to determine the DMAA content in such products, a nuclear magnetic resonance (NMR) spectroscopic method was developed and validated (DMAA was quantified as DMAA-HCl). For quantification, the collective integral from two of the methyl groups of the molecule in the range δ 0.92-0.84 ppm was used. The method was linear over the examined range of 1-21 g/kg (R(2) = 0.9937). The recoveries from spiked concentrations (0.1-6 g/kg) ranged between 85% and 105% (96% on average), with a relative standard deviation (RSD) of 1% for an authentic sample. The detection limit was 0.03 g/kg and the quantification limit was 0.08 g/kg (calculated for 75 mg sample weight). The actual DMAA-HCl content in the sample was quantified using calibration curves (external standardization) or 3,5-dinitrobenzoic acid as single-point internal standard. The developed NMR methodology was applied for the analysis of 16 products, from which 9 samples were found positive (the DMAA-HCl concentration varied between 3.1 g/kg and 415 g/kg). The method can be recommended for routine use in food testing, customs or doping control laboratories. PMID:24913715

  16. International symposium on NMR spectroscopy

    The publication consists of 32 papers and presentations from the field of NMR spectroscopy applications submitted to the International Symposium on NMR Spectroscopy held at Smolenice between 29 Sep and 3 Oct, 1980. (B.S.)

  17. Stability and molecular dynamics of solid lasamide (API of diuretic and antivirial drugs) studied by 1H NMR spectroscopy and DFT methods

    Latosińska, J. N.; Latosińska, M.; Medycki, W.

    2009-08-01

    Temperature dependence of the relaxation time T1 (in the ranges: 10-200 K at 24.667 MHz; 105-460 K at 90 MHz) and the second moment of the NMR line for protons M2 (in the range: 130-400 K, 24.667 MHz) in a polycrystalline sample of 2,4-dichloro-5-sulfamoyl-benzoic acid (lasamide) an Active Pharmaceutical Ingredient of both diuretic and antiviral drugs have been measured. The results have revealed two activation processes: the concerted proton transfer in inter-molecular double hydrogen bonds (the low-temperature T1 minimum at about 92 K; the activation energy 5.02 kJ/mol) and the jumps of the -NH 2 group (the high-temperature, 2 Gs 2 reduction of the second moment; the activation energy 48 kJ/mol). The low-temperature flattening of the T1 dependence stretched up to the helium temperatures indicating the incoherent tunnelling in the proton transfer dynamics.

  18. Observation by flow 1H NMR and dimerization kinetics and products of reactive ortho-quinodimethanes and benzocyclobutadiene

    The reactive o-quinodimethanes, 1,2-dimethylene-1,2-dihydronaphthalene (9) and o-xylylene (1) were observed by flow 1H NMR spectroscopy at room temperature. The 1H NMR spectrum of 9 was obtained in the absence of precursor and dimers. However, the 1H NMR spectrum of the more reactive 1, generated in a similar manner from [o-((trimethylsilyl)methyl)benzyl]trimethylammonium iodide (5.) could be obtained only in the presence of its stable [4 + 2] and [4 + 4] dimers. The dimerization kinetics of 3-methyl- (5'), 3,6-dimethyl- (11), 3-isopropyl- (12), and 3,6-diisoproply-1,2-xylylene (13) in acetonitrile (CH3CN) were studied by stopped-flow UV-visible spectroscopy. Fluoride ion induced 1,2-elimination from 2-elimination from 2-trimethylsilylbenzocyclobutenyl-1 mesylate (26) was used to generate the reactive molecule benzocyclobutadiene (1') in CD3CN, which was observed by flow 1H NMR spectroscopy at room temperature. The 1H NMR spectrum (in CD3CN) of 1,2-dimethylene-1,2-dihydrothiophene (1 double-prime), obtained by fluoride ion induced 1,4-elimination from 3-(trimethylammoniummethyl)-2-(trimethylsilylmethyl)thiophene iodine was observed by flow 1H NMR spectroscopy at room temperature. The dimerization rate of 1 double-prime in CH3CN, generated in the same manner, was measured by UV-visible spectroscopy. 166 refs., 7 figs., 7 tabs

  19. Wine analysis to check quality and authenticity by fully-automated 1H-NMR

    Spraul Manfred

    2015-01-01

    Full Text Available Fully-automated high resolution 1H-NMR spectroscopy offers unique screening capabilities for food quality and safety by combining non-targeted and targeted screening in one analysis (15–20 min from acquisition to report. The advantage of high resolution 1H-NMR is its absolute reproducibility and transferability from laboratory to laboratory, which is not equaled by any other method currently used in food analysis. NMR reproducibility allows statistical investigations e.g. for detection of variety, geographical origin and adulterations, where smallest changes of many ingredients at the same time must be recorded. Reproducibility and transferability of the solutions shown are user-, instrument- and laboratory-independent. Sample prepara- tion, measurement and processing are based on strict standard operation procedures which are substantial for this fully automated solution. The non-targeted approach to the data allows detecting even unknown deviations, if they are visible in the 1H-NMR spectra of e.g. fruit juice, wine or honey. The same data acquired in high-throughput mode are also subjected to quantification of multiple compounds. This 1H-NMR methodology will shortly be introduced, then results on wine will be presented and the advantages of the solutions shown. The method has been proven on juice, honey and wine, where so far unknown frauds could be detected, while at the same time generating targeted parameters are obtained.

  20. Dynamic 1H NMR Studies of Schiff Base Derivatives

    Köylü, M. Z.; Ekinci, A.; Böyükata, M.; Temel, H.

    2016-01-01

    The spin-lattice relaxation time T 1 and the spin-spin relaxation time T 2 of two Schiff base derivatives, N,N'-ethylenebis(salicylidene)-1,2-diaminoethane (H2L1) and N,N'-ethylenebis (salicylidene)-1,3-diaminopropane (H2L2), in DMSO-d6 solvent were studied as a function of temperature in the range of 20-50°C using a Bruker Avance 400.132 MHz 1H NMR spectrometer. Based on the activation energy ( E a) and correlation time (τc), we believe that the Schiff base derivatives perform a molecular tumbling motion.

  1. Solution behavior and complete 1H and 13C NMR assignments of the coenzyme B12 derivative (5'-deoxyadenosyl)cobinamide using modern 2D NMR experiments, including 600-MHz 1H NMR data

    Two-dimensional (2D) NMR methods have been used to assign completely the 1H and 13C NMR spectra of the (5'-deoxyadenosyl)cobinamide cation (AdoCbi+) in D2O. Most of the 1H spectral assignments were made by using 2D homonuclear shift correlation spectroscopy (COSY), homonuclear Hartmann-Hahn spectroscopy (HOHAHA), absorption-mode (phase sensitive) 2D nuclear Overhauser effect (NOE) spectroscopy, and spin-locked NOE spectroscopy (also called ROESY, for rotating-frame Overhauser enhancement spectroscopy). Most of the protonated carbon resonances were assigned by using 1H-detected heteronuclear multiple-quantum coherence (HMQC) spectroscopy. The nonprotonated carbon resonances, as well as the remaining unassigned 1H and 13C NMR signals, were assigned from long-range 1H-13C connectivities determined from 1H-detected multiple-bond heteronuclear multiple-quantum coherence spectroscopy (HMBC). Comparison of the 13C chemical shifts and 1H NOEs of AdoCbi+ with those of coenzyme B12 ((5'-deoxyadenosyl)cobalamin) and its benzimidazole-protonated, base-off form indicates that the electronic properties and structure of AdoCbi+ are similar to that of coenzyme B12 in the protonated, base-off form. The 13C chemical shifts of most of the carbons of AdoCbi+ do not vary significantly from those of base-off, benzimidazole-protonated coenzyme B12, indicating that the electronic environment of the corrin ring is also similar in both compounds. However, significant differences in the chemical shifts of some of the corresponding carbons of the b, d, e, and f corrin side chains in AdoCbi+ and in base-off, benzimidazole-protonated coenzyme B12 indicate that the positions of these side chains may be different in AdoCbi+ compared to base-off coenzyme B12

  2. Discrimination of sugarcane according to cultivar by 1H NMR and chemometric analyses

    Alves Filho, Elenilson G.; Silva, Lorena M.A.; Choze, Rafael; Liao, Luciano M. [Laboratorio de Ressonancia Magnetica Nuclear, Instituto de Quimica, Universidade Federal de Goias (UFG), Goiania, GO (Brazil); Honda, Neli K.; Alcantara, Glaucia B. [Departamento de Quimica, Universidade Federal de Mato Grosso do Sul (UFMS), Campo Grande, MS (Brazil)

    2012-07-01

    Several technologies for the development of new sugarcane cultivars have mainly focused on the increase in productivity and greater disease resistance. Sugarcane cultivars are usually identified by the organography of the leaves and stems, the analysis of peroxidase and esterase isoenzyme activities and the total soluble protein as well as soluble solid content. Nuclear magnetic resonance (NMR) associated with chemometric analysis has proven to be a valuable tool for cultivar assessment. Thus, this article describes the potential of chemometric analysis applied to 1H high resolution magic angle spinning (HRMAS) and NMR in solution for the investigation of sugarcane cultivars. For this purpose, leaves from eight different cultivars of sugarcane were investigated by {sup 1}H NMR spectroscopy in combination with chemometric analysis. The approach shows to be a useful tool for the distinction and classification of different sugarcane cultivars as well as to access the differences on its chemical composition. (author)

  3. Quantitative analysis of sugars in wood hydrolyzates with 1H NMR during the autohydrolysis of hardwoods.

    Mittal, Ashutosh; Scott, Gary M; Amidon, Thomas E; Kiemle, David J; Stipanovic, Arthur J

    2009-12-01

    The focus of this work was to determine the utility of (1)H NMR spectroscopy in the quantification of sugars resulting from the solubilization of hemicelluloses during the autohydrolysis of hardwoods and the use of this technique to evaluate the kinetics of this process over a range of temperatures and times. Yields of residual xylan, xylooligomers, xylose, glucose, and the degraded products of sugars, i.e., furfural and HMF (5-hydroxymethyl furfural), were determined. The monosaccharide and oligomer contents were quantified with a recently developed high resolution (1)H NMR spectroscopic analysis. This method provided precise measurement of the residual xylan and cellulose remaining in the extracted wood samples and xylose and glucose in the hydrolyzates. NMR was found to exhibit good repeatability and provided carbohydrate compositional results comparable to published methods for sugar maple and aspen woods. PMID:19674893

  4. 1H and 13C NMR investigation of 20-hydroxyecdysone dioxolane derivatives, a novel group of MDR modulator agents.

    Balázs, Attila; Hunyadi, Attila; Csábi, József; Jedlinszki, Nikoletta; Martins, Ana; Simon, András; Tóth, Gábor

    2013-12-01

    The synthesis, structure elucidation and the complete (1)H and (13)C signal assignment of a series of dioxolane derivatives of 20-hydroxyecdysone, synthesized as novel modulators of multidrug resistance, are presented. The structures and NMR signal assignment were established by comprehensive one-dimensional and two-dimensional NMR spectroscopy supported by mass spectrometry. PMID:24114927

  5. Correlative and quantitative 1H NMR-based metabolomics reveals specific metabolic pathway disturbances in diabetic rats

    Zhang, Shucha; Gowda, G. A. Nagana; Asiago, Vincent; Shanaiah, Narasimhamurthy; Barbas, Coral; Raftery, Daniel

    2008-01-01

    Type 1 diabetes was induced in Sprague–Dawley rats using streptozotocin. Rat urine samples (8 diabetic and 10 control) were analyzed by 1H nuclear magnetic resonance (NMR) spectroscopy. The derived metabolites using univariate and multivariate statistical analysis were subjected to correlative analysis. Plasma metabolites were measured by a series of bioassays. A total of 17 urinary metabolites were identified in the 1H NMR spectra and the loadings plots after principal components analysis. D...

  6. Analysis of adulterated herbal medicines and dietary supplements marketed for weight loss by DOSY 1H NMR

    VAYSSE, Julie; BALAYSSAC, Stéphane; GILARD, Véronique; DESOUBZDANNE, Denis; MALET-MARTINO, Myriam; Martino, Robert

    2010-01-01

    Abstract Twenty herbal medicines or dietary supplements marketed as natural slimming products were analyzed by Diffusion Ordered SpectroscopY (DOSY) 1H NMR and DOSY-COSY 1H NMR. The method allows analysis of the whole sample with detection of both active and inactive ingredients in these complex matrices. Among the 20 formulations analyzed, 2 were strictly herbal and 4 had a composition corresponding to declared ingredients on the packaging or the leaflet. The others were all adult...

  7. Comparison of Metabolite Concentrations in the Left Dorsolateral Prefrontal Cortex, the Left Frontal White Matter, and the Left Hippocampus in Patients in Stable Schizophrenia Treated with Antipsychotics with or without Antidepressants. 1H-NMR Spectroscopy Study

    Dominik Strzelecki

    2015-10-01

    Full Text Available Managing affective, negative, and cognitive symptoms remains the most difficult therapeutic problem in stable phase of schizophrenia. Efforts include administration of antidepressants. Drugs effects on brain metabolic parameters can be evaluated by means of proton nuclear magnetic resonance (1H-NMR spectroscopy. We compared spectroscopic parameters in the left prefrontal cortex (DLPFC, the left frontal white matter (WM and the left hippocampus and assessed the relationship between treatment and the spectroscopic parameters in both groups. We recruited 25 patients diagnosed with schizophrenia (DSM-IV-TR, with dominant negative symptoms and in stable clinical condition, who were treated with antipsychotic and antidepressive medication for minimum of three months. A group of 25 patients with schizophrenia, who were taking antipsychotic drugs but not antidepressants, was matched. We compared metabolic parameters (N-acetylaspartate (NAA, myo-inositol (mI, glutamatergic parameters (Glx, choline (Cho, and creatine (Cr between the two groups. All patients were also assessed with the Positive and Negative Syndrome Scale (PANSS and the Calgary Depression Scale for Schizophrenia (CDSS. In patients receiving antidepressants we observed significantly higher NAA/Cr and NAA/Cho ratios within the DLPFC, as well as significantly higher mI/Cr within the frontal WM. Moreover, we noted significantly lower values of parameters associated with the glutamatergic transmission—Glx/Cr and Glx/Cho in the hippocampus. Doses of antipsychotic drugs in the group treated with antidepressants were also significantly lower in the patients showing similar severity of psychopathology.

  8. 1H NMR spectroscopic determination of deterioration marker compounds in fats and oils

    Skiera, Christina

    2013-01-01

    In food and pharmaceutical analysis, the classical indices peroxide value (PV), acid value (AV) and p-anisidine value (ANV) still play an important role as quality and authenticity control parameters of fats and oils. These indices are sum parameters for certain deterioration products (PV for hydroperoxides, AV for free fatty acids, ANV for aldehydes) and are obtained using volumetric or UV/VIS spectroscopic analytical approaches. 1H NMR spectroscopy provides a fast and simple alternative to ...

  9. Primary structure determination of five sialylated oligosaccharides derived from bronchial- mucus glycoproteins of patients suffering from cystic fibrosis. The occurrence of the NeuAcα(2→3)Galα(1→4)[Fucα(1→3)]GlcNAcα(1→.) structural element revealed by 500-MHz 1H NMR spectroscopy

    Vliegenthart, J.F.G.; Lamblin, G.; Boersma, A.; Klein, A.; Roussel, P.; Halbeek, H. van

    1984-01-01

    The structure of sialylated carbohydrate units of bronchial mucins obtained from cystic fibrosis patients was investigated by 500-MHz 1H NMR spectroscopy in conjunction with sugar analysis. After subjecting the mucins to alkaline borohydride degradation, sialylated oligosaccharide-alditols were isol

  10. Synergistic effect of the simultaneous chemometric analysis of 1H NMR spectroscopic and stable isotope (SNIF-NMR, 18O, 13C) data: Application to wine analysis

    Highlights: • 1H NMR profilings of 718 wines were fused with stable isotope analysis data (SNIF-NMR, 18O, 13C). • The best improvement was obtained for prediction of the geographical origin of wine. • Certain enhancement was also obtained for the year of vintage (from 88 to 97% for 1H NMR to 99% for the fused data). • Independent component analysis was used as an alternative chemometric tool for classification. - Abstract: It is known that 1H NMR spectroscopy represents a good tool for predicting the grape variety, the geographical origin, and the year of vintage of wine. In the present study we have shown that classification models can be improved when 1H NMR profiles are fused with stable isotope (SNIF-NMR, 18O, 13C) data. Variable selection based on clustering of latent variables was performed on 1H NMR data. Afterwards, the combined data of 718 wine samples from Germany were analyzed using linear discriminant analysis (LDA), partial least squares-discriminant analysis (PLS-DA), factorial discriminant analysis (FDA) and independent components analysis (ICA). Moreover, several specialized multiblock methods (common components and specific weights analysis (ComDim), consensus PCA and consensus PLS-DA) were applied to the data. The best improvement in comparison with 1H NMR data was obtained for prediction of the geographical origin (up to 100% for the fused data, whereas stable isotope data resulted only in 60–70% correct prediction and 1H NMR data alone in 82–89% respectively). Certain enhancement was obtained also for the year of vintage (from 88 to 97% for 1H NMR to 99% for the fused data), whereas in case of grape varieties improved models were not obtained. The combination of 1H NMR data with stable isotope data improves efficiency of classification models for geographical origin and vintage of wine and can be potentially used for other food products as well

  11. 口腔癌患者血清核磁共振代谢组学研究%Metabonomic studies of serum obtained from oral cancer patients using 1H NMR spectroscopy

    黄奇骏; 姚婕; 黎玉君; 翁合妹; 龚嘉欣; 丘翠环; 杨永霞

    2013-01-01

    Objective To research the metabolite compositions of the serum samples from oral cancer patients by using nuclear magnetic resonance (NMR) based metabonomics. Methods NMR 1H spectra were measured for serum samples from 10 healthy volunteers and 10 oral cancer patients. The spectra data were analyzed by principal component analysis (PCA) to reveal the metabonomic profiles of serum from oral cancer patients and the corresponding biochemical changes. Results There were obvious metabonomic differences between healthy volunteers and oral cancer patients which were highlighted by the increased levels in amino acids (leucine, isoleucine, valine, tyrosine, phenylalanine, his-tidine), glutamate,glycoprotein, methylamine, dimethylamine and glucose, together with the decreased levels of lactate and choline in oral cancer patients. Conclusion The results show that the metabonome of serum from oral cancer patients differ markedly from that of the healthy volunteers, which indicates that serum NMR 'H spectroscopy in conjunction with PCA offers an efficient tool for the diagnosis of oral cancer.%目的 应用核磁共振代谢组学方法研究口腔癌患者血清代谢组的特征及其变化.方法健康人血清(健康组,10例)和口腔癌患者血清(口腔癌组,10例)样本,采用BRUKER 500 MHz 超导核磁共振波谱仪进行检测,运用PCA分析方法,研究口腔癌患者血清代谢组的特征,探讨相关生化过程的改变.结果健康组与口腔癌组患者血清代谢谱有不同的代谢特征.口腔癌患者血清中氨基酸(亮氨酸、异亮氨酸、缬氨酸、酪氨酸、苯丙氨酸、组氨酸),谷氨酸、糖蛋白、甲胺和二甲胺、葡萄糖的含量是升高的,而乳酸和胆碱的含量降低.结论根据血清代谢物的变化可以区分健康人和口腔癌患者.这种基于核磁共振氢谱的代谢组学方法可为口腔癌的诊断提供可靠代谢依据.

  12. Identification, synthesis and characterization of an unknown process related impurity in eslicarbazepine acetate active pharmaceutical ingredient by LC/ESI-IT/MS, 1H, 13C and 1H-1H COSY NMR

    Saji Thomas; Saroj Kumar Paul; Subhash Chandra Joshi; Vineet Kumar; Ashutosh Agarwal; Dharam Vir

    2014-01-01

    A new impurity was detected during high performance liquid chromatographic (HPLC) analysis of eslicarbazepine acetate active pharmaceutical ingredient. The structure of unknown impurity was postulated based on liquid chromatography mass spectrometry using electrospray ionization and ion trap analyzer (LC/ESI-IT/MS) analysis. Proposed structure of impurity was unambiguously confirmed by synthesis followed by characterization using 1H, 13C nuclear magnetic resonance spectrometry (NMR), 1H-1H correlation spectro-scopy (COSY) and infrared spectroscopy (IR). Based on the spectroscopic and spectrometric data, unknown impurity was characterized as 5-carbamoyl-10,11-dihydro-5H-dibenzo[b,f]azepin-10-yl propionate.

  13. 1H NMR spectroscopic studies establish that heparanase is a retaining glycosidase

    Highlights: •1H and 13C NMR chemical shifts of fondaparinux were fully assigned by 1D and 2D NMR techniques. •Hydrolysis of fondaparinux by heparanase was monitored by 1H NMR spectroscopy. •Heparanase is established to be a retaining glycosidase. -- Abstract: Heparanase is an endo-β-glucuronidase that cleaves heparan sulfate side chains of proteoglycans in basement membranes and the extracellular matrix (ECM). Heparanase is implicated in several diverse pathological processes associated with ECM degradation such as metastasis, inflammation and angiogenesis and is thus an important target for anti-cancer and anti-inflammatory drug discovery. Heparanase has been classed as belonging to the clan A glycoside hydrolase family 79 based on sequence analysis, secondary structure predictions and mutagenic analysis, and thus it has been inferred that it is a retaining glycosidase. However, there has been no direct experimental evidence to support this conclusion. Herein we describe 1H NMR spectroscopic studies of the hydrolysis of the pentasaccharide substrate fondaparinux by heparanase, and provide conclusive evidence that heparanase hydrolyses its substrate with retention of configuration and is thus established as a retaining glycosidase. Knowledge of the mechanism of hydrolysis may have implications for future design of inhibitors for this important drug target

  14. {sup 1}H NMR spectroscopic studies establish that heparanase is a retaining glycosidase

    Wilson, Jennifer C., E-mail: jennifer.wilson@griffith.edu.au [Institute for Glycomics, Griffith University Gold Coast Campus, QLD 4222 (Australia); Laloo, Andrew Elohim [School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, QLD 4072 (Australia); Singh, Sanjesh [Institute for Glycomics, Griffith University Gold Coast Campus, QLD 4222 (Australia); Ferro, Vito, E-mail: v.ferro@uq.edu.au [School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, QLD 4072 (Australia)

    2014-01-03

    Highlights: •{sup 1}H and {sup 13}C NMR chemical shifts of fondaparinux were fully assigned by 1D and 2D NMR techniques. •Hydrolysis of fondaparinux by heparanase was monitored by {sup 1}H NMR spectroscopy. •Heparanase is established to be a retaining glycosidase. -- Abstract: Heparanase is an endo-β-glucuronidase that cleaves heparan sulfate side chains of proteoglycans in basement membranes and the extracellular matrix (ECM). Heparanase is implicated in several diverse pathological processes associated with ECM degradation such as metastasis, inflammation and angiogenesis and is thus an important target for anti-cancer and anti-inflammatory drug discovery. Heparanase has been classed as belonging to the clan A glycoside hydrolase family 79 based on sequence analysis, secondary structure predictions and mutagenic analysis, and thus it has been inferred that it is a retaining glycosidase. However, there has been no direct experimental evidence to support this conclusion. Herein we describe {sup 1}H NMR spectroscopic studies of the hydrolysis of the pentasaccharide substrate fondaparinux by heparanase, and provide conclusive evidence that heparanase hydrolyses its substrate with retention of configuration and is thus established as a retaining glycosidase. Knowledge of the mechanism of hydrolysis may have implications for future design of inhibitors for this important drug target.

  15. Automated data evaluation and modelling of simultaneous (19) F-(1) H medium-resolution NMR spectra for online reaction monitoring.

    Zientek, Nicolai; Laurain, Clément; Meyer, Klas; Paul, Andrea; Engel, Dirk; Guthausen, Gisela; Kraume, Matthias; Maiwald, Michael

    2016-06-01

    Medium-resolution nuclear magnetic resonance spectroscopy (MR-NMR) currently develops to an important analytical tool for both quality control and process monitoring. In contrast to high-resolution online NMR (HR-NMR), MR-NMR can be operated under rough environmental conditions. A continuous re-circulating stream of reaction mixture from the reaction vessel to the NMR spectrometer enables a non-invasive, volume integrating online analysis of reactants and products. Here, we investigate the esterification of 2,2,2-trifluoroethanol with acetic acid to 2,2,2-trifluoroethyl acetate both by (1) H HR-NMR (500 MHz) and (1) H and (19) F MR-NMR (43 MHz) as a model system. The parallel online measurement is realised by splitting the flow, which allows the adjustment of quantitative and independent flow rates, both in the HR-NMR probe as well as in the MR-NMR probe, in addition to a fast bypass line back to the reactor. One of the fundamental acceptance criteria for online MR-MNR spectroscopy is a robust data treatment and evaluation strategy with the potential for automation. The MR-NMR spectra are treated by an automated baseline and phase correction using the minimum entropy method. The evaluation strategies comprise (i) direct integration, (ii) automated line fitting, (iii) indirect hard modelling (IHM) and (iv) partial least squares regression (PLS-R). To assess the potential of these evaluation strategies for MR-NMR, prediction results are compared with the line fitting data derived from the quantitative HR-NMR spectroscopy. Although, superior results are obtained from both IHM and PLS-R for (1) H MR-NMR, especially the latter demands for elaborate data pretreatment, whereas IHM models needed no previous alignment. Copyright © 2015 John Wiley & Sons, Ltd. PMID:25854892

  16. A Guided Inquiry Approach to NMR Spectroscopy

    Parmentier, Laura E.; Lisensky, George C.; Spencer, Brock

    1998-04-01

    We present a novel way to introduce NMR spectroscopy into the general chemistry curriculum as part of a week-long aspirin project in our one-semester introductory course. Aspirin is synthesized by reacting salicylic acid and acetic anhydride. Purity is determined by titration and IR and NMR spectroscopy. Students compare IR and NMR spectra of their aspirin product to a series of reference spectra obtained by the class. Students are able to interpret the IR spectra of their aspirin using IR data from previous experiments. NMR is introduced by having students collect 1H NMR spectra of a series of reference compounds chosen to include some of the structural features of aspirin and compare spectra and structures of the reference compounds to develop a correlation chart for chemical shifts. This process is done in small groups using shared class data and is guided by a series of questions designed to relate the different kinds of hydrogen atoms to number and position of peaks in the NMR spectrum. Students then identify the peaks in the NMR spectrum of their aspirin product and relate percent purity by titration with spectral results and percent yield. This is an enjoyable project that combines the synthesis of a familiar material with a guided inquiry-based introduction to NMR spectroscopy.

  17. Observation by flow sup 1 H NMR and dimerization kinetics and products of reactive ortho-quinodimethanes and benzocyclobutadiene

    Fischer, D.

    1990-09-21

    The reactive o-quinodimethanes, 1,2-dimethylene-1,2-dihydronaphthalene (9) and o-xylylene (1) were observed by flow {sup 1}H NMR spectroscopy at room temperature. The {sup 1}H NMR spectrum of 9 was obtained in the absence of precursor and dimers. However, the {sup 1}H NMR spectrum of the more reactive 1, generated in a similar manner from (o-((trimethylsilyl)methyl)benzyl)trimethylammonium iodide (5.) could be obtained only in the presence of its stable (4 + 2) and (4 + 4) dimers. The dimerization kinetics of 3-methyl- (5{prime}), 3,6-dimethyl- (11), 3-isopropyl- (12), and 3,6-diisoproply-1,2-xylylene (13) in acetonitrile (CH{sub 3}CN) were studied by stopped-flow UV-visible spectroscopy. Fluoride ion induced 1,2-elimination from 2-elimination from 2-trimethylsilylbenzocyclobutenyl-1 mesylate (26) was used to generate the reactive molecule benzocyclobutadiene (1{prime}) in CD{sub 3}CN, which was observed by flow {sup 1}H NMR spectroscopy at room temperature. The {sup 1}H NMR spectrum (in CD{sub 3}CN) of 1,2-dimethylene-1,2-dihydrothiophene (1{double prime}), obtained by fluoride ion induced 1,4-elimination from 3-(trimethylammoniummethyl)-2-(trimethylsilylmethyl)thiophene iodine was observed by flow {sup 1}H NMR spectroscopy at room temperature. The dimerization rate of 1{double prime} in CH{sub 3}CN, generated in the same manner, was measured by UV-visible spectroscopy. 166 refs., 7 figs., 7 tabs.

  18. Application of 1H-NMR metabolomic profiling for reef-building corals.

    Emilia M Sogin

    Full Text Available In light of global reef decline new methods to accurately, cheaply, and quickly evaluate coral metabolic states are needed to assess reef health. Metabolomic profiling can describe the response of individuals to disturbance (i.e., shifts in environmental conditions across biological models and is a powerful approach for characterizing and comparing coral metabolism. For the first time, we assess the utility of a proton-nuclear magnetic resonance spectroscopy (1H-NMR-based metabolomics approach in characterizing coral metabolite profiles by 1 investigating technical, intra-, and inter-sample variation, 2 evaluating the ability to recover targeted metabolite spikes, and 3 assessing the potential for this method to differentiate among coral species. Our results indicate 1H-NMR profiling of Porites compressa corals is highly reproducible and exhibits low levels of variability within and among colonies. The spiking experiments validate the sensitivity of our methods and showcase the capacity of orthogonal partial least squares discriminate analysis (OPLS-DA to distinguish between profiles spiked with varying metabolite concentrations (0 mM, 0.1 mM, and 10 mM. Finally, 1H-NMR metabolomics coupled with OPLS-DA, revealed species-specific patterns in metabolite profiles among four reef-building corals (Pocillopora damicornis, Porites lobata, Montipora aequituberculata, and Seriatopora hystrix. Collectively, these data indicate that 1H-NMR metabolomic techniques can profile reef-building coral metabolomes and have the potential to provide an integrated picture of the coral phenotype in response to environmental change.

  19. Application of 1H-NMR Metabolomic Profiling for Reef-Building Corals

    Sogin, Emilia M.; Anderson, Paul; Williams, Philip; Chen, Chii-Shiarng; Gates, Ruth D.

    2014-01-01

    In light of global reef decline new methods to accurately, cheaply, and quickly evaluate coral metabolic states are needed to assess reef health. Metabolomic profiling can describe the response of individuals to disturbance (i.e., shifts in environmental conditions) across biological models and is a powerful approach for characterizing and comparing coral metabolism. For the first time, we assess the utility of a proton-nuclear magnetic resonance spectroscopy (1H-NMR)-based metabolomics approach in characterizing coral metabolite profiles by 1) investigating technical, intra-, and inter-sample variation, 2) evaluating the ability to recover targeted metabolite spikes, and 3) assessing the potential for this method to differentiate among coral species. Our results indicate 1H-NMR profiling of Porites compressa corals is highly reproducible and exhibits low levels of variability within and among colonies. The spiking experiments validate the sensitivity of our methods and showcase the capacity of orthogonal partial least squares discriminate analysis (OPLS-DA) to distinguish between profiles spiked with varying metabolite concentrations (0 mM, 0.1 mM, and 10 mM). Finally, 1H-NMR metabolomics coupled with OPLS-DA, revealed species-specific patterns in metabolite profiles among four reef-building corals (Pocillopora damicornis, Porites lobata, Montipora aequituberculata, and Seriatopora hystrix). Collectively, these data indicate that 1H-NMR metabolomic techniques can profile reef-building coral metabolomes and have the potential to provide an integrated picture of the coral phenotype in response to environmental change. PMID:25354140

  20. A 1H NMR study of human calcitonin in solution

    Human calcitonin (hCT) has been investigated by NMR at 400 MHz in DMSOd6 and in an 85% DMSOd6-15% 1H2O (v/v) cryoprotective mixture. All backbone and side-chain resonances have been assigned and the secondary structure has been determined in both solvents. In DMSOd6, the simultaneous presence of dαN, dNN, and some specific weak medium-range nuclear Overhauser effects, together with the amide temperature coefficients and the analysis of the NH-αCH spin-spin coupling constants, indicates that hCT is highly flexible but with three domains (comprising segments Asn3-Gly10, Gln14-Thr21, and Thr25-Ala31) in extended conformations which dynamically transform into isolated β turns in the N- and C-terminal regions and into adjacent tight turns, resembling a 310 helix structure, in the central part. The DMSO-water mixture rigidifies the polypeptide chain, favoring and ordered, extended conformation. NOESY data indicate the presence of a short double-stranded antiparallel β sheet in the central region made by residues 16-21 and connected by a two-residue hairpin loop formed by residues 18 and 19. Two tight turns, formed by residues 3-6 and 28-31, were also identified. The central β sheet does not favor an amphipathic distribution of the residues as found for salmon calcitonin. This is in agreement with the smaller tendency of hCT to form the amphipathic α helix, postulated to be responsible for the interaction of hCT with lipids. The possible role of the cis-trans isomerism of Pro is discussed

  1. Structure elucidation of the blood group B like and blood group I active octaantennary ceramide tetracontasaccharide from rabbit erythrocyte membranes by two-dimensional 1H NMR spectroscopy at 600 MHz

    The primary structure of the ceramide tetracontasaccharide (1) from rabbit erythrocyte membranes has been determined with the aid of 600-MHz two-dimensional phase-sensitive correlated, totally correlated (TOCSY, homonuclear Hartmann-Hahn), relayed coherence transfer, triple quantum filtered, and nuclear Overhauser enhancement 1H NMR spectra. It was shown that obtaining subspectra of the constituent sugar residues from a totally correlated spectrum and assigning the resonances occurring in these subspectra by analyzing the relevant cross-peaks in phase-sensitive correlated spectra is the most efficient way for establishing complex oligosaccharide structures. This analysis has shown 1 to be the highest homologue of the multiantennary neolactoglycosphingolipids

  2. Classification of ginseng berry (Panax ginseng C.A. MEYER) extract using 1H NMR spectroscopy and its inhibition of lipid accumulation in 3 T3-L1 cells

    Yang, Seung Ok; Park, Hae Ran; Sohn, Eun Suk; Lee, Sang Won; Kim, Hyung Don; Kim, Young Chang; Kim, Kee Hong; Na, Sae Won; Choi, Hyung-Kyoon; Arasu, Mariadhas Valan; Kim, Young Ock

    2014-01-01

    Background Panax ginseng is a famous traditional medicine in Korea for its beneficial effect on obesity, cardiac and liver associated diseases. The aim of this study was to investigate the metabolite in Panax ginseng (P. ginseng, Aralicaceae) berries depending on the ripen stages and evaluate its potential inhibition on adipocyte differentiation in 3 T3-L1 cells. Methods Different ripening stage samples of P. ginseng berry were analyzed through global metabolite profiling by NMR spectroscopy....

  3. 1H NMR investigation of self-association of vanillin in aqueous solution

    A self-association of vanillin have been studied by 1H NMR spectroscopy using the analysis of proton chemical shifts changes in aqueous solution as a function of concentration. The experimental results have been analysed using indefinite non-cooperative and cooperative models of molecular self-association, enabling the determination of equilibrium constants, parameters of cooperativity and the limiting values of vanillin proton chemical shifts in the complex. It was found that the dimer formation creates energetically favourable conditions for subsequent molecular association.

  4. {sup 1}H NMR investigation of self-association of vanillin in aqueous solution

    Bogdan, Mircea; Floare, Calin G; PIrnau, Adrian, E-mail: mircea.bogdan@itim-cj.r [National Institute for Research and Development of Isotopic and Molecular Technologies, 65-103 Donath, 400293 Cluj-Napoca (Romania)

    2009-08-01

    A self-association of vanillin have been studied by {sup 1}H NMR spectroscopy using the analysis of proton chemical shifts changes in aqueous solution as a function of concentration. The experimental results have been analysed using indefinite non-cooperative and cooperative models of molecular self-association, enabling the determination of equilibrium constants, parameters of cooperativity and the limiting values of vanillin proton chemical shifts in the complex. It was found that the dimer formation creates energetically favourable conditions for subsequent molecular association.

  5. 1H NMR investigation of self-association of vanillin in aqueous solution

    Bogdan, Mircea; Floare, Calin G.; Pîrnau, Adrian

    2009-08-01

    A self-association of vanillin have been studied by 1H NMR spectroscopy using the analysis of proton chemical shifts changes in aqueous solution as a function of concentration. The experimental results have been analysed using indefinite non-cooperative and cooperative models of molecular self-association, enabling the determination of equilibrium constants, parameters of cooperativity and the limiting values of vanillin proton chemical shifts in the complex. It was found that the dimer formation creates energetically favourable conditions for subsequent molecular association.

  6. 1H Nuclear Magnetic Resonance (NMR) metabonomic study of breast cancer in Indian population

    Breast cancer is the most common cancer diagnosed in women worldwide with over 1.3 million new cases per year. Recently it has been observed that breast cancer is increasing very rapidly in low income countries including India. Lipids not only play very important and vital role of prime structural component in human body they are also important functional components in cellular metabolism. Transformation from benign to malignant tissue involves several biochemical processes and understanding these processes provides very useful insight related to cancer prognosis. Thus study of lipids becomes very important and NMR spectroscopy is one of the techniques which can be utilized to identifying all lipid components simultaneously. The tissue specimens (35, benign 20 and malignant 15; patient age group 47 yrs) were collected after breast surgeries and were snap frozen in liquid nitrogen. Part of all tissues was sent for routine histopathology. Lipid extraction was performed by Folch method (Folch, 1957) using cholesterol and methanol (2:1 ratio). The NMR spectra of the extracted lipids were recorded immediately after the sample preparation. All NMR experiments were performed on a Bruker Avance 800 MHz spectrometer. 1H NMR analysis of lipid extract of breast tissue in Indian population shows there is significant elevation of phosphotidycholine, plasmalogen and esterified cholesterol with decrease in triacylglycerol in cancer breast compared to benign tissue implying that their metabolism is definitely altered during carcinogenesis. This study analyzes the role of NMR as an additional diagnostic tool on the basis of examination of lipid extract. (author)

  7. Characterization of Hydrogenated Fullerenes by NMR Spectroscopy

    Hedenström, Mattias; Wågberg, Thomas; Johnels, Dan

    NMR spectroscopy is so far the only analytical technique that has been used to get a detailed structural characterization of hydrogenated fullerenes. A substantial amount of information derived from different NMR experiments can thus be found in the literature for a number of fullerenes hydrogenated to various degrees. These studies have benefitted from the fact that chemical shifts of 1H and 13C and in some cases also 3He can be used to obtain structural information of these compounds. Such results, together with discussions about different NMR experiments and general considerations regarding sample preparations, are summarized in this chapter. The unique information, both structural and physicochemical, that can be derived from different NMR experiments ensures that this technique will continue to be of central importance in characterization of hydrogenated fullerenes.

  8. LC-MS and 1H NMR as an improved dereplication tool to identify antifungal diterpenoids from Sagittaria latifolia

    A dereplication strategy using a combination of liquid chromatography-mass spectrometry (LC-MS) and proton nuclear magnetic resonance spectroscopy (1H NMR) to facilitate compound identification towards antifungal natural product discovery is presented. This analytical approach takes advantage of th...

  9. Annual reports on NMR spectroscopy

    Webb, Graham A; McCarthy, M J

    1995-01-01

    Over recent years, no other technique has grown to such importance as that of NMR spectroscopy. It is used in all branches of science where precise structural determination is required and where the nature of interactions and reactions in solution is being studied. Annual Reports on NMR Spectroscopy has established itself as a means for the specialist and non-specialist alike to become familiar with new applications of the technique in all branches of chemistry, including biochemistry, and pharmaceutics. This volume focuses on theoretical aspects of NMR nuclear shielding and on applications of

  10. Fundamentals of Protein NMR Spectroscopy

    Rule, Gordon S

    2006-01-01

    NMR spectroscopy has proven to be a powerful technique to study the structure and dynamics of biological macromolecules. Fundamentals of Protein NMR Spectroscopy is a comprehensive textbook that guides the reader from a basic understanding of the phenomenological properties of magnetic resonance to the application and interpretation of modern multi-dimensional NMR experiments on 15N/13C-labeled proteins. Beginning with elementary quantum mechanics, a set of practical rules is presented and used to describe many commonly employed multi-dimensional, multi-nuclear NMR pulse sequences. A modular analysis of NMR pulse sequence building blocks also provides a basis for understanding and developing novel pulse programs. This text not only covers topics from chemical shift assignment to protein structure refinement, as well as the analysis of protein dynamics and chemical kinetics, but also provides a practical guide to many aspects of modern spectrometer hardware, sample preparation, experimental set-up, and data pr...

  11. Automatic 1H-NMR Screening of Fatty Acid Composition in Edible Oils

    David Castejón

    2016-02-01

    Full Text Available In this work, we introduce an NMR-based screening method for the fatty acid composition analysis of edible oils. We describe the evaluation and optimization needed for the automated analysis of vegetable oils by low-field NMR to obtain the fatty acid composition (FAC. To achieve this, two scripts, which automatically analyze and interpret the spectral data, were developed. The objective of this work was to drive forward the automated analysis of the FAC by NMR. Due to the fact that this protocol can be carried out at low field and that the complete process from sample preparation to printing the report only takes about 3 min, this approach is promising to become a fundamental technique for high-throughput screening. To demonstrate the applicability of this method, the fatty acid composition of extra virgin olive oils from various Spanish olive varieties (arbequina, cornicabra, hojiblanca, manzanilla, and picual was determined by 1H-NMR spectroscopy according to this protocol.

  12. Automatic 1H-NMR Screening of Fatty Acid Composition in Edible Oils

    Castejón, David; Fricke, Pascal; Cambero, María Isabel; Herrera, Antonio

    2016-01-01

    In this work, we introduce an NMR-based screening method for the fatty acid composition analysis of edible oils. We describe the evaluation and optimization needed for the automated analysis of vegetable oils by low-field NMR to obtain the fatty acid composition (FAC). To achieve this, two scripts, which automatically analyze and interpret the spectral data, were developed. The objective of this work was to drive forward the automated analysis of the FAC by NMR. Due to the fact that this protocol can be carried out at low field and that the complete process from sample preparation to printing the report only takes about 3 min, this approach is promising to become a fundamental technique for high-throughput screening. To demonstrate the applicability of this method, the fatty acid composition of extra virgin olive oils from various Spanish olive varieties (arbequina, cornicabra, hojiblanca, manzanilla, and picual) was determined by 1H-NMR spectroscopy according to this protocol. PMID:26891323

  13. UV-vis, IR and 1H NMR spectroscopic studies and characterization of ionic-pair crystal violet-oxytetracycline

    Orellana, Sandra; Soto, César; Toral, M. Inés

    2010-01-01

    The present study shows the formation and characterization of the ionic-pair between the antibiotic oxytetracycline and the dye crystal violet in ammonia solution pH 9.0 ± 0.2 extracted into chloroform. The characterization was demonstrated using UV-vis spectrophotometry, 1H NMR, measurement of relaxation times T1 and IR spectroscopy, using a comparison between the signals of individual pure compounds with the signals with the mixture CV-OTC in different alkaline media. The formation of ionic-pair was also corroborated by new signals and chemical shifts. (2D) NMR spectroscopy experiments show that the interaction is electrostatic.

  14. 1H-NMR-based metabolomic profiling of CSF in early amyotrophic lateral sclerosis.

    Hélène Blasco

    Full Text Available BACKGROUND: Pathophysiological mechanisms involved in amyotrophic lateral sclerosis (ALS are complex and none has identified reliable markers useful in routine patient evaluation. The aim of this study was to analyze the CSF of patients with ALS by (1H NMR (Nuclear Magnetic Resonance spectroscopy in order to identify biomarkers in the early stages of the disease, and to evaluate the biochemical factors involved in ALS. METHODOLOGY: CSF samples were collected from patients with ALS at the time of diagnosis and from patients without neurodegenerative diseases. One and two-dimensional (1H NMR analyses were performed and metabolites were quantified by the ERETIC method. We compared the concentrations of CSF metabolites between both groups. Finally, we performed principal component (PCA and discriminant analyses. PRINCIPAL FINDINGS: Fifty CSF samples from ALS patients and 44 from controls were analyzed. We quantified 17 metabolites including amino-acids, organic acids, and ketone bodies. Quantitative analysis revealed significantly lower acetate concentrations (p = 0.0002 in ALS patients compared to controls. Concentration of acetone trended higher (p = 0.015, and those of pyruvate (p = 0.002 and ascorbate (p = 0.003 were higher in the ALS group. PCA demonstrated that the pattern of analyzed metabolites discriminated between groups. Discriminant analysis using an algorithm of 17 metabolites revealed that patients were accurately classified 81.6% of the time. CONCLUSION/SIGNIFICANCE: CSF screening by NMR spectroscopy could be a useful, simple and low cost tool to improve the early diagnosis of ALS. The results indicate a perturbation of glucose metabolism, and the need to further explore cerebral energetic metabolism.

  15. Sequential 1H NMR assignments and secondary structure of hen egg white lysozyme in solution

    Assignments of 1H NMR resonances of 121 of the 129 residues of hen egg white lysozyme have been obtained by sequence-specific methods. Spin systems were identified with phase-sensitive two-dimensional (2-D) correlated spectroscopy and single and double relayed coherence transfer spectroscopy. For key types of amino acid residues, particularly alanine, threonine, valine, and glycine, complete spin systems were identified. For other residues a less complete definition of the spin system was found to be adequate for the purpose of sequential assignment. Sequence-specific assignments were achieved by phase-sensitive 2-D nuclear Overhauser enhancement spectroscopy (NOESY). Exploitation of the wide range of hydrogen exchange rates found in lysozyme was a useful approach to overcoming the problem of spectral overlap. The sequential assignment was built up from 21 peptide segments ranging in length from 2 to 13 residues. The NOESY spectra were also used to provide information about the secondary structure of the protein in solution. Three helical regions and two regions of β-sheet were identified from the NOESY data; these regions are identical with those found in the X-ray structure of hen lysozyme. Slowly exchanging amides are generally correlated with hydrogen bonding identified in the X-ray structure; a number of exceptions to this general trend were, however, found. The results presented in this paper indicate that highly detailed information can be obtained from 2-D NMR spectra of a protein that is significantly larger than those studies previously

  16. On the {sup 1}H NMR spectra of 2-substituted benzoquinones

    Tedeschi, E.; Rezende, D.B. [Universidade de Sao Paulo (USP), SP (Brazil). Inst. de Quimica; Arruda Campos, I.P. de, E-mail: ipdacamp@uol.com.br [Universidade Paulista, Sao Paulo, SP (Brazil). Inst. de Ciencias Exatas e Tecnologia. Programa de Pos-Graduacao em Engenharia de Producao

    2009-07-01

    The novel complete analysis of the {sup 1}H NMR spectra of six monosubstituted benzoquinones is reported herein, together with a brief but complete review of the scanty previously published data on benzoquinone and its monosubstituded derivatives. (author)

  17. Dolphin: a tool for automatic targeted metabolite profiling using 1D and 2D (1)H-NMR data.

    Gómez, Josep; Brezmes, Jesús; Mallol, Roger; Rodríguez, Miguel A; Vinaixa, Maria; Salek, Reza M; Correig, Xavier; Cañellas, Nicolau

    2014-12-01

    One of the main challenges in nuclear magnetic resonance (NMR) metabolomics is to obtain valuable metabolic information from large datasets of raw NMR spectra in a high throughput, automatic, and reproducible way. To date, established software packages used to match and quantify metabolites in NMR spectra remain mostly manually operated, leading to low resolution results and subject to inconsistencies not attributable to the NMR technique itself. Here, we introduce a new software package, called Dolphin, able to automatically quantify a set of target metabolites in multiple sample measurements using an approach based on 1D and 2D NMR techniques to overcome the inherent limitations of 1D (1)H-NMR spectra in metabolomics. Dolphin takes advantage of the 2D J-resolved NMR spectroscopy signal dispersion to avoid inconsistencies in signal position detection, enhancing the reliability and confidence in metabolite matching. Furthermore, in order to improve accuracy in quantification, Dolphin uses 2D NMR spectra to obtain additional information on all neighboring signals surrounding the target metabolite. We have compared the targeted profiling results of Dolphin, recorded from standard biological mixtures, with those of two well established approaches in NMR metabolomics. Overall, Dolphin produced more accurate results with the added advantage of being a fully automated and high throughput processing package. PMID:25370160

  18. Liver Metabolite Concentrations Measured with 1H MR Spectroscopy

    Ouwerkerk, Ronald; PETTIGREW, RODERIC I.; Gharib, Ahmed M.

    2012-01-01

    In vivo measurement of liver choline concentrations in healthy humans is feasible, and even measurement of glycogen can be achieved in some patients at 3.0 T with point-resolved 1H MR spectroscopy by using navigator-guided synchronization to respiratory motion and state-of-the-art B0 field shimming techniques.

  19. 1H NMR profiling as an approach to differentiate conventionally and organically grown tomatoes.

    Hohmann, Monika; Christoph, Norbert; Wachter, Helmut; Holzgrabe, Ulrike

    2014-08-20

    This study describes the approach of (1)H NMR profiling for the authentication of organically produced tomatoes (Solanum lycopersicum). Overall, 361 tomato samples of two different cultivars and four different producers were regularly analyzed during a 7 month period. The results of principal component analysis showed a significant trend for the separation between organically and conventionally produced tomatoes (p cultivation method, yet the results indicate significant differences between (1)H NMR spectra of organically and conventionally grown tomatoes. PMID:25066078

  20. Structure and dynamics of model membranes by advanced NMR spectroscopy

    The molecular conformation and dynamics of phospholipids have important implications for the detailed understanding of membrane function, fluidity, composition and protein-lipid interaction. The advanced nuclear magnetic resonance (NMR) methods used in the study of structure and dynamics of model membranes are reviewed. Conformational exchange of the lipid headgroup as well as segmental order can be measured using dipolar couplings between the nuclei 31 P - 1 H, 13 C - 1 H, 1 H - 1 H and 31 P - 13 C by a novel solid-state two-dimensional (2D) NMR technique. Self-diffusion of lipids and water in lipid bilayers measured by sensitive NMR method of fringe field of superconducting magnet as well as 2D deuterium exchange NMR spectroscopy are presented. The powerful method of 2D NOESY in establishing the intermolecular interaction between an antineoplastic drug (daunomycin) and a model membrane is discussed. (authors)

  1. Age-Related 1H NMR Characterization of Cerebrospinal Fluid in Newborn and Young Healthy Piglets

    Barone, Francesca; Elmi, Alberto; Romagnoli, Noemi; Bacci, Maria Laura

    2016-01-01

    When it comes to neuroscience, pigs represent an important animal model due to their resemblance with humans’ brains for several patterns including anatomy and developmental stages. Cerebrospinal fluid (CSF) is a relatively easy-to-collect specimen that can provide important information about neurological health and function, proving its importance as both a diagnostic and biomedical monitoring tool. Consequently, it would be of high scientific interest and value to obtain more standard physiological information regarding its composition and dynamics for both swine pathology and the refinement of experimental protocols. Recently, proton nuclear magnetic resonance (1H NMR) spectroscopy has been applied in order to analyze the metabolomic profile of this biological fluid, and results showed the technique to be highly reproducible and reliable. The aim of the present study was to investigate in both qualitative and quantitative manner the composition of Cerebrospinal Fluid harvested form healthy newborn (5 days old-P5) and young (30-P30 and 50-P50 days old) piglets using 1H NMR Spectroscopy, and to analyze any possible difference in metabolites concentration between age groups, related to age and Blood-Brain-Barrier maturation. On each of the analyzed samples, 30 molecules could be observed above their limit of quantification, accounting for 95–98% of the total area of the spectra. The concentrations of adenine, tyrosine, leucine, valine, 3-hydroxyvalerate, 3-methyl-2-oxovalerate were found to decrease between P05 and P50, while the concentrations of glutamine, creatinine, methanol, trimethylamine and myo-inositol were found to increase. The P05-P30 comparison was also significant for glutamine, creatinine, adenine, tyrosine, leucine, valine, 3-hydroxyisovalerate, 3-methyl-2-oxovalerate, while for the P30-P50 comparison we found significant differences for glutamine, myo-inositol, leucine and trimethylamine. None of these molecules showed at P30 concentrations

  2. 应用1H-NMR研究高果糖对白脂肪组织代谢组的影响%Application of 1H-NMR Spectroscopy for Investigating Effects of High Fructose on Metabonome of White Adipose Tissues of Rats

    杨永霞; 郑凌云; 陈阿丽; 王亚玲; 王琳琳; 韩智慧

    2015-01-01

    Objective To study the metabolomics changes of white adipose tissues in insulin resistance rats induced by fructose feeding by using 1H nuclear magnetic resonance(1H-NMR). Methods Sixteen Wistar rats were evenly divided into control group and model group after adaptive feeding for one week. Rats in the model group were given 100 g/L of fructose water for 8 weeks to induce insulin resistance,and rats in the control group were given pure water in the same volume as the model group. At the end of the 8th week, the white adipose tissues were isolated and the 1H-NMR spectrum of each sample was collected for principal component analysis. Results Compared with the control group,the metabolomics of the white adipose tissues in model rats had obvious changes, showing as higher levels of alanine, trimethylamine oxide/betaine, choline and glycerol, and lower levels of lactic acid, lipid, glutamate, choline glycerophosphate/phosphatidylcholine, and unsaturated lipid, and the differences were statistically significant. Conclusion 1H-NMR based on metabonomics method can show the metabolic characteristics of white adipose tissues in insulin resistance rats induced by high fructose feeding,and provide biochemical changes of white adipose tissues.%目的:采用基于核磁共振的代谢组学方法研究高果糖喂养对白脂肪代谢组的影响。方法选取16只Wistar大鼠,将其适应1周后随机分为正常对照组和模型组,每组8只。采用100 g·L-1果糖水饲喂8周建立胰岛素抵抗(insulin resistance,IR)模型,对照组给予与模型组等体积的纯净水。8周末取大鼠白脂肪组织,运用主成分方法(principal component analysis,PCA)对白脂肪组织水溶性提取液的核磁共振氢谱(1H-NMR)谱进行分析。结果与正常对照组比较,模型组大鼠的白脂肪组织代谢组明显变化,其中丙氨酸、氧化三甲胺/甜菜碱、胆碱和丙三醇含量升高,乳酸、脂质、谷氨酸、甘油

  3. Discrimination of the geographical origin of beef by (1)H NMR-based metabolomics.

    Jung, Youngae; Lee, Jueun; Kwon, Joseph; Lee, Kwang-Sik; Ryu, Do Hyun; Hwang, Geum-Sook

    2010-10-13

    The geographical origin of beef is of increasing interest to consumers and producers due to "mad cow" disease and the implementation of the Free Trade Agreement (FTA). In this study, (1)H NMR spectroscopy coupled with multivariate statistical analyses was used to differentiate the geographical origin of beef samples. Principal component analysis (PCA) and orthogonal projection to latent structure-discriminant analysis (OPLS-DA) showed significant separation between extracts of beef originating from four countries: Australia, Korea, New Zealand, and the United States. The major metabolites responsible for differentiation in OPLS-DA loading plots were succinate and various amino acids including isoleucine, leucine, methionine, tyrosine, and valine. A one-way ANOVA was performed to statistically certify the difference in metabolite levels. The data suggest that NMR-based metabolomics is an efficient method to distinguish fingerprinting difference between raw beef samples, and several metabolites including various amino acids and succinate can be possible biomarkers for discriminating the geographical origin of beef. PMID:20831251

  4. Combined Analysis of Stable Isotope, (1)H NMR, and Fatty Acid To Verify Sesame Oil Authenticity.

    Kim, Jeongeun; Jin, Gyungsu; Lee, Yunhee; Chun, Hyang Sook; Ahn, Sangdoo; Kim, Byung Hee

    2015-10-14

    The aim of this study was to verify the authenticity of sesame oils using combined analysis of stable isotope ratio, (1)H NMR spectroscopy, and fatty acid profiles of the oils. Analytical data were obtained from 35 samples of authentic sesame oils and 29 samples of adulterated sesame oils currently distributed in Korea. The orthogonal projection to latent structure discriminant analysis technique was used to select variables that most effectively verify the sesame oil authenticity. The variables include δ(13)C value, integration values of NMR peaks that signify the CH3 of n-3 fatty acids, CH2 between two C═C, protons from sesamin/sesamolin, and 18:1n-9, 18:3n-3, 18:2t, and 18:3t content values. The authenticity of 65 of 70 blind samples was correctly verified by applying the range of the eight variables found in the authentic sesame oil samples, suggesting that triple analysis is a useful approach to verify sesame oil authenticity. PMID:26395416

  5. Biochemical effects of gadolinium chloride in rats liver and kidney studied by 1H NMR metabolomics

    LIAO Peiqiu; WEI Lai; Wu Huifeng; LI Weisheng; WU Yijie; LI Xiaojing; NI Jiazuan; PEI Fengkui

    2009-01-01

    The biochemical effects of gadolinium chloride were studied using high-resolution IH nuclear magnetic resonance (NMR) spec-troscopy to investigate the biochemical composition of tissue (liver and kidney) aqueous extracts obtained from control and gadolinium chlo-ride (GdCl3) (10 and 50 mg/kg body weight, intraperitoneal injection, i.p.) treated rats. Tissue samples were collected at 48, 96 and 168 h p.d. after exposure to GdCl3, and extracted using methanol/chloroform solvent system. 1H NMR spectra of tissue extracts were analyzed by pat-tern recognition using principal components analysis. The liver damages caused by GdCl3 were characterized by increased succinate and de-creased glycogen level and elevated lactate, alanine and betaine concentration in liver. Furthermore, the increase of creatine and lactate, and decrease of glutamate, alanine, phosphocholine, glycophosphocholine (GPC), betaine, myo-inositoi and trimethylamine N-oxide (TMAO)levels in kidney illustrated kidney disturbance induced by GdCl3.

  6. 35Cl and 1H NMR study of anion binding to reduced bovine copper-zinc superoxide dismutase

    Binding of chloride to reduced bovine copper-zinc superoxide dismutase (Cu2Zn2SOD) and chemically modified derivatives was monitored by the line width at half-height of the Cl- resonance as measured by 35Cl nuclear magnetic resonance (NMR) spectroscopy. Reduced arginine-modified and reduced lysine-modified Cu2Zn2SOD (at concentrations of 2.14 x 10-4 M) caused less broadening of the Cl- resonance line width of 0.1 M NaCl solutions than did reduced native protein when measured under the same conditions; Cl- broadening with all protein derivatives decreased drastically in the presence of 0.05 M phosphate. The C-H and N-H proton resonances of histidyl imidazoles of reduced native and reduced lysine-modified Cu2Zn2SOD were shifted by addition of Cl- (with apparent affinity constants of 12 and ∼ 2 M-1, respectively) whereas this anion had less effect in the 1H NMR spectrum of reduced arginine-modified Cu2Zn2SOD (affinity constant -1) under the same conditions. phosphate caused relatively smaller changes on the 1H NMR resonances of all reduced protein derivatives. The competition measured by 1H NMR spectroscopy between chloride and phosphate for anion binding sites in the neighborhood of the Cu1 ion was much less than that for nonspecific Cl- binding monitored by 35Cl NMR spectroscopy. It is concluded from these experiments that, in addition to the weak anion binding at or near the CuI ion, Arg-141, Lys-120, and Lys-134 serve as major anion binding sites in the reduced native protein. 57 refs., 5 figs., 2 tabs

  7. Binding mechanism of the tyrosine-kinase inhibitor nilotinib to human serum albumin determined by (1)H STD NMR, (19)F NMR, and molecular modeling.

    Yan, Jin; Wu, Di; Sun, Pingchuan; Ma, Xiaoli; Wang, Lili; Li, Shanshan; Xu, Kailin; Li, Hui

    2016-05-30

    Drug interaction with albumins significantly affects in vivo drug transport and biological metabolism. To gain insight into the binding mechanisms of tyrosine-kinase inhibitor nilotinib (NIL) to human serum albumin (HSA), an approach combining (1)H saturation-transfer difference (STD) nuclear magnetic resonance (NMR) spectroscopy, (19)F NMR spectroscopy, steady-state fluorescence quenching, and molecular modeling was adopted. (19)F NMR was used to determine the binding constant, and a value of 4.12×10(3)M(-1) was obtained. Fluorescence spectroscopy was also used to determine the binding constant, and the value obtained was within the same order of magnitude. The binding process was mainly driven by hydrogen bonds and van der Waals forces. Displacement experiments further showed that NIL mainly bound to the hydrophobic cavity of HSA's subdomain IIA, also called Sudlow's site I. Molecular docking simulation was also used to establish a molecular binding model, and findings were consistent with those of displacement and the (1)H STD NMR experiments. PMID:26922576

  8. A survey on quantitative analysis of organic compounds by nuclear magnetic resonance (NMR) spectroscopy

    Nuclear Magnetic Resonance (NMR) spectroscopy is known as a powerful analytical technique, which is used to determine the structure of small and macro organic compounds. In recent years, 1H NMR is being recognized more and more as a quantitative analytical method, which is based on the principle where the area under a 1H NMR signal peak in solution state is proportional to the number of nuclei contributing to the peak. In this report, the basic concepts, developmental history and current state of the quantitative 1H NMR (qNMR) method are described. Furthermore, future prospect of the qNMR method is presented. (author)

  9. Factors affecting the robustness of metabolite fingerprinting using 1H NMR spectra.

    Defernez, Marianne; Colquhoun, Ian J

    2003-03-01

    1H NMR spectroscopy is one of the techniques whose potential is currently being explored in the emerging field of metabolomics. It is a non-targeted method, producing signals for all proton-containing chemical species. For crude plant materials the spectra are always complex, with many signals overlapping. Hence a most suitable approach for analysing them is 'metabolite fingerprinting', which is aimed at highlighting compositional similarities and exploring the overall natural variability in a population of samples. The most commonly used method for this is principal component analysis (PCA), as it allows the whole spectral trace to be analysed and the vast quantity of information to be simplified. In this paper we investigate whether there are factors which may affect the NMR spectra in a way that subsequently decreases the robustness of the metabolite fingerprinting by PCA. Imperfections in the signal registration (i.e. inconsistency of the peak position) are generally detrimental to analysing whole traces by multivariate methods. The sources of such problems are illustrated through specially designed repeatability studies using potato and tomato samples, and the analysis of a tea dataset containing many samples. Careful sample preparation can help to limit peak shifts; for instance here by attempting to control the pH of the extracts. In addition, some compounds are susceptible to interactions affecting their chemical shifts and mathematical alignment of peaks may be necessary. Lastly factors such as resolution can also affect analyses and must be carefully adjusted. Our choice of examples aims to raise awareness of potential problems. We do not question the validity of the NMR approach, but point out those areas where special care may need to be taken. PMID:12590127

  10. 1H NMR based metabolic profiling in the evaluation of Japanese green tea quality.

    Tarachiwin, Lucksanaporn; Ute, Koichi; Kobayashi, Akio; Fukusaki, Eiichiro

    2007-11-14

    Classification of tea quality is now mainly performed according to the sensory results by professional tea tasters. However, this evaluation method is inconsistent in differentiating their qualities. A combination of a (1)H NMR technique and a multivariate analysis was introduced to the quality evaluation of green tea by means of a metabolomic technique. A broad range of metabolites were detected by (1)H NMR spectrometry. The principal component analysis (PCA) was used to reduce the complexity of the (1)H NMR spectra data set and provided the quality discrimination result. It offered an extensive clue for classification and quality assessment without any prepurification method. A set of green teas from a Japanese tea contest were analyzed by (1)H NMR to classify the quality with respect to that judged by tea tasters and to conceive a quality prediction model. Metabolic profiling and fingerprinting of (1)H NMR spectra of green teas with different quality were studied. PCA showed a separation between the high- and the low-quality green teas. The taste marker compounds contributing to the discrimination of tea quality were identified. Reliable prediction models were obtained by the partial least-squares projection to latent structure (PLS) analysis together with a preprocessing filter of both orthogonal signal correction (OSC) and a combination between OSC and wavelet transform algorithms. PMID:17944534

  11. Side-chain dynamics of a detergent-solubilized membrane protein: Measurement of tryptophan and glutamine hydrogen-exchange rates in M13 coat protein by 1H NMR spectroscopy

    M13 coat protein is a small (50 amino acids) lipid-soluble protein that becomes an integral membrane protein during the infection stage of the life cycle of the M13 phage and is therefore used as a model membrane protein. To study side-chain dynamics in the protein, the authors have measured individual hydrogen-exchange rates for a primary amide in the side chain of glutamine-15 and for the indole amine of tryptophan-26. The protein was solubilized with the use of perdeuteriated sodium dodecyl sulfate (SDS), and hydrogen-exchange rates were measured by using 1H nuclear magnetic resonance spectroscopy. The glutamine-15 syn proton exchanged at a rate identical with that in glutamine model peptides except that the pH corresponding to minimum exchange was elevated by about 1.5 pH units. The tryptophan-26 indole amine proton exchange was biphasic, suggesting that two populations of tryptophan-26 exist. It is suggested that the two populations may reflect protein dimerization or aggregation in the SDS micelles. The pH values of minimum exchange for tryptophan-26 in both environments were also elevated by 1.3-1.9 pH units. This phenomenon is reproduced when small tryptophan- and glutamine-containing hydrophobic peptides are dissolved in the presence of SDS micelles. The electrostatic nature of this phenomenon is proven by showing that the minimum pH for exchange can be reduced by dissolving the hydrophobic peptides in the positively charged detergent micelle dodecyltrimethylammonium bromide

  12. Structural proteomics by NMR spectroscopy.

    Shin, Joon; Lee, Woonghee; Lee, Weontae

    2008-08-01

    Structural proteomics is one of the powerful research areas in the postgenomic era, elucidating structure-function relationships of uncharacterized gene products based on the 3D protein structure. It proposes biochemical and cellular functions of unannotated proteins and thereby identifies potential drug design and protein engineering targets. Recently, a number of pioneering groups in structural proteomics research have achieved proof of structural proteomic theory by predicting the 3D structures of hypothetical proteins that successfully identified the biological functions of those proteins. The pioneering groups made use of a number of techniques, including NMR spectroscopy, which has been applied successfully to structural proteomics studies over the past 10 years. In addition, advances in hardware design, data acquisition methods, sample preparation and automation of data analysis have been developed and successfully applied to high-throughput structure determination techniques. These efforts ensure that NMR spectroscopy will become an important methodology for performing structural proteomics research on a genomic scale. NMR-based structural proteomics together with x-ray crystallography will provide a comprehensive structural database to predict the basic biological functions of hypothetical proteins identified by the genome projects. PMID:18761469

  13. 23Na and 1H NMR studies on melittin channels activated by tricyclic tranquilizers.

    Tanaka, H.; Matsunaga, K.; Kawazura, H

    1992-01-01

    A dynamic 23Na nuclear magnetic resonance (NMR) technique was applied to the exchange system of Na+ ions present inside and outside large unilamellar vesicles at an equivalent concentration. Addition of melittin to phosphatidylcholine vesicles did not induce any detectable Na+ transport across the membrane but subsequent addition of a trace of chlorpromazine or imipramine did induce Na+ transport. Because the formation of a drug-melittin adduct in a solution was detected by 1H NMR, the activa...

  14. SU-E-I-34: Intermittent Low- and High-Dose Ethanol Exposure Alters Neurochemical Responses in Adult Rat Brain: An Ex Vivo 1H NMR Spectroscopy at 11.7 T

    Lee, Do-Wan; Kim, Sang-Young; Song, Kyu-Ho; Choe, Bo-Young [Department of Biomedical Engineering, and Research Institute of Biomedical Engineering, The Catholic University of Korea College of Medicine, Seoul (Korea, Republic of)

    2014-06-01

    Purpose: The first goal of this study was to determine the influence of the dose-dependent effects of intermittent ethanol intoxication on cerebral neurochemical responses among sham controls and low- and high-dose-ethanol-exposed rats with ex vivo high-resolution spectra. The second goal of this study was to determine the correlations between the metabolite-metabolite levels (pairs-of-metabolite levels) from all of the individual data from the frontal cortex of the intermittent ethanol-intoxicated rats. Methods: Eight-week-old male Wistar rats were divided into 3 groups. Twenty rats in the LDE (n = 10) and the HDE (n = 10) groups received ethanol doses of 1.5 g/kg and 2.5 g/kg, respectively, through oral gavage every 8-h for 4 days. At the end of the 4-day intermittent ethanol exposure, one-dimensional ex vivo 500-MHz proton nuclear magnetic resonance spectra were acquired from 30 samples of the frontal cortex region (from the 3 groups). Results: Normalized total-N-acetylaspartate (tNAA: NAA + NAAG [N-acetylaspartyl-glutamate]), gamma-aminobutyric acid (GABA), and glutathione (GSH) levels were significantly lower in the frontal cortex of the HDE-exposed rats than that of the LDE-exposed rats. Moreover, compared to the CNTL group, the LDE rats exhibited significantly higher normalized GABA levels. The 6 pairs of normalized metabolite levels were positively (+) or negatively (−) correlated in the rat frontal cortex as follows: tNAA and GABA (+), tNAA and Aspartate (Asp) (−), myo-Inositol (mIns) and Asp (−), mIns and Alanine (+), mIns and Taurine (+), and mIns and tNAA (−). Conclusion: Our results suggested that repeated intermittent ethanol intoxication might result in neuronal degeneration and dysfunction, changes in the rate of GABA synthesis, and oxidative stress in the rat frontal cortex. Our ex vivo 1H high-resolution-magic angle spinning nuclear magnetic resonance spectroscopy results suggested some novel metabolic markers for the dose

  15. SU-E-I-34: Intermittent Low- and High-Dose Ethanol Exposure Alters Neurochemical Responses in Adult Rat Brain: An Ex Vivo 1H NMR Spectroscopy at 11.7 T

    Purpose: The first goal of this study was to determine the influence of the dose-dependent effects of intermittent ethanol intoxication on cerebral neurochemical responses among sham controls and low- and high-dose-ethanol-exposed rats with ex vivo high-resolution spectra. The second goal of this study was to determine the correlations between the metabolite-metabolite levels (pairs-of-metabolite levels) from all of the individual data from the frontal cortex of the intermittent ethanol-intoxicated rats. Methods: Eight-week-old male Wistar rats were divided into 3 groups. Twenty rats in the LDE (n = 10) and the HDE (n = 10) groups received ethanol doses of 1.5 g/kg and 2.5 g/kg, respectively, through oral gavage every 8-h for 4 days. At the end of the 4-day intermittent ethanol exposure, one-dimensional ex vivo 500-MHz proton nuclear magnetic resonance spectra were acquired from 30 samples of the frontal cortex region (from the 3 groups). Results: Normalized total-N-acetylaspartate (tNAA: NAA + NAAG [N-acetylaspartyl-glutamate]), gamma-aminobutyric acid (GABA), and glutathione (GSH) levels were significantly lower in the frontal cortex of the HDE-exposed rats than that of the LDE-exposed rats. Moreover, compared to the CNTL group, the LDE rats exhibited significantly higher normalized GABA levels. The 6 pairs of normalized metabolite levels were positively (+) or negatively (−) correlated in the rat frontal cortex as follows: tNAA and GABA (+), tNAA and Aspartate (Asp) (−), myo-Inositol (mIns) and Asp (−), mIns and Alanine (+), mIns and Taurine (+), and mIns and tNAA (−). Conclusion: Our results suggested that repeated intermittent ethanol intoxication might result in neuronal degeneration and dysfunction, changes in the rate of GABA synthesis, and oxidative stress in the rat frontal cortex. Our ex vivo 1H high-resolution-magic angle spinning nuclear magnetic resonance spectroscopy results suggested some novel metabolic markers for the dose

  16. Localization of epileptogenic focus by 1H MR spectroscopy

    In fourteen patients suffering from pharmacoresistant epilepsy with partial complex seizures, 1H MR spectra from the left and right hippocampus were assessed. From the ratios NAA/Cr, NAA/Cho and NAA/(Cr+Cho) the asymmetry coefficient was calculated which characterizes the reduced NAA (N-acetyl aspartate) concentration in the assumed epileptogenic focus. An agreement between MRS and the EEG findings was found in 10 out of 14 cases, i.e. in 71%. MR spectroscopy is therefore another non-invasive diagnostic method suitable for the assessment of lateralization of an epileptic focus before epileptosurgery. (author) 2 tabs., 3 figs., 30 refs

  17. Novel determination of the total phenolic content in crude plant extracts by the use of 1H NMR of the -OH spectral region

    A novel method for the determination of the total phenolic content using 1H NMR spectroscopy in the -OH spectral region is presented. The use of DMSO-d6, which is an aprotic and strongly hydrogen bonding solvent, allows the 'appearance' of the relative sharp resonances of phenolic hydroxyl protons in the region of 8-14 ppm. The determination of the total phenolic -OH content requires three steps: (i) a 1D 1H NMR spectrum is obtained in DMSO-d6; (ii) a subsequent 1D 1H NMR spectrum is recorded with irradiation of the residual water signal which results in the elimination or reduction of the phenolic -OH groups, due to proton exchange; and (iii) 1D 1H NMR spectra are recorded with the addition of a progressively increased amount of salt, NaHCO3, which results in extensive linebroadening of the COOH resonances thus allowing the discrimination of the phenolic from the carboxylic acid signals. Integration, with respect to the internal standard TSP-d4, of the signal resonances between 14 and 8 ppm in spectrum (i) which are either eliminated or reduced in intensity in steps (ii) and (iii) allows the quantitation of the total phenolic content. The method was applied to model compounds, a mixture of them and several extracts of natural products. The results of the proposed 1H NMR method were compared to the Folin-Ciocalteu (FC) reagent method. Additionally, since 1H NMR refers to the total phenolic hydroxyl protons, a reaction factor, Ae, is proposed that corresponds to the hydroxyl reactivity. The 1H NMR method is rapid and accurate bearing the inherent advantages of the NMR spectroscopy and can be applied directly in complex extracts. Furthermore, it can be applied in a wide range of matrixes from crude plant extracts and food products to biological samples.

  18. Quantification of aldehyde impurities in poloxamer by 1H NMR spectrometry

    This work presents a fast and simple quantitative method for impurity determination of acetaldehyde and propionaldehyde in poloxamer 188 by proton nuclear magnetic resonance spectroscopy (1H NMR). The sample is dissolved in D2O with DCl and analyzed with a 600 MHz NMR spectrometer. Data processing, including filtering by convolution of spectra with a triangular function and integration, is performed in MATLAB. The repeated studies of one sample, including automatic gradient shimming and data processing, revealed a relative standard deviation (R.S.D.) of 2.8%. For the reproducibility, also including sample preparation, the R.S.D. was less than 10%. The predictability of a linear calibration model was estimated by the root mean square error of prediction from leave-one-out cross-validation (RMSECV). Using 64 scans, RMSECV was found to be 7.2 and 5.5 μg g-1 for acetaldehyde and propionaldehyde respectively for a 4.3-min acquisition time. The limits of detection, defined as three times the noise, reached 19 and 15 μg g-1 respectively under the same experimental conditions. These limits are sufficient to quantify 80 and 100 μg g-1 of the impurities, which has been found to be the maximum allowed content in the poloxamer for some medical applications. Thus the method has the potential to replace the current liquid chromatography (LC) method for impurity determination of acetaldehyde and propionaldehyde in poloxamer, which is time-consuming and includes a work-up procedure involving many steps

  19. Evaluation of 1H NMR relaxometry for the assessment of pore size distribution in soil samples

    Jaeger, F.; Bowe, S.; As, van H.; Schaumann, G.E.

    2009-01-01

    1H NMR relaxometry is used in earth science as a non-destructive and time-saving method to determine pore size distributions (PSD) in porous media with pore sizes ranging from nm to mm. This is a broader range than generally reported for results from X-ray computed tomography (X-ray CT) scanning, wh

  20. Polypharmacotherapy in rheumatology: 1H NMR analysis of binding of phenylbutazone and methotrexate to serum albumin

    Maciążek-Jurczyk, M.; Sułkowska, A.; Równicka-Zubik, J.; Bojko, B.; Szkudlarek-Haśnik, A.; Knopik, M.; Sułkowski, W. W.

    2011-05-01

    The influence of phenylbutazone (Phe) and methotrexate (MTX) on binding of MTX and Phe to human (HSA) and bovine (BSA) serum albumin in the low-affinity binding sites is investigated. The strength and kind of interactions between serum albumin (SA) and drugs used in combination therapy were found using 1H NMR spectroscopy. A stoichiometric molar ratios for Phe-SA and MTX-SA complexes are 36:1 and 31:1, respectively. It appeared these molar ratios are higher for the ternary systems than it were in the binary ones. The presence of the additional drug (MTX or Phe) causes the increase of an affinity of albumin towards Phe and MTX. It was found that the aliphatic groups of MTX are more resistant to the influence of Phe on the MTX-SA complex than the aromatic rings. The results showed the important impact of another drug (MTX or Phe) on the affinity of SA towards Phe and MTX in the low-affinity binding sites. This work is a subsequent part of the spectroscopic study on Phe-MTX-SA interactions (Maciążek-Jurczyk, 2009 [1]).

  1. A novel Bayesian approach to quantify clinical variables and to determine their spectroscopic counterparts in 1H NMR metabonomic data

    Kaski Kimmo

    2007-05-01

    Full Text Available Abstract Background A key challenge in metabonomics is to uncover quantitative associations between multidimensional spectroscopic data and biochemical measures used for disease risk assessment and diagnostics. Here we focus on clinically relevant estimation of lipoprotein lipids by 1H NMR spectroscopy of serum. Results A Bayesian methodology, with a biochemical motivation, is presented for a real 1H NMR metabonomics data set of 75 serum samples. Lipoprotein lipid concentrations were independently obtained for these samples via ultracentrifugation and specific biochemical assays. The Bayesian models were constructed by Markov chain Monte Carlo (MCMC and they showed remarkably good quantitative performance, the predictive R-values being 0.985 for the very low density lipoprotein triglycerides (VLDL-TG, 0.787 for the intermediate, 0.943 for the low, and 0.933 for the high density lipoprotein cholesterol (IDL-C, LDL-C and HDL-C, respectively. The modelling produced a kernel-based reformulation of the data, the parameters of which coincided with the well-known biochemical characteristics of the 1H NMR spectra; particularly for VLDL-TG and HDL-C the Bayesian methodology was able to clearly identify the most characteristic resonances within the heavily overlapping information in the spectra. For IDL-C and LDL-C the resulting model kernels were more complex than those for VLDL-TG and HDL-C, probably reflecting the severe overlap of the IDL and LDL resonances in the 1H NMR spectra. Conclusion The systematic use of Bayesian MCMC analysis is computationally demanding. Nevertheless, the combination of high-quality quantification and the biochemical rationale of the resulting models is expected to be useful in the field of metabonomics.

  2. Applications of 1H-NMR relaxometry in experimental liver studies

    Purpose of this study was to investigate applications of proton nuclear magnetic resonance (1H-NMR) relaxometry in experimental medicine. Relaxometry was performed by measurements of spin-lattice (T1) and spin-spin (T2) relaxation time parameters on liver biopsies up to four hours after biopsy excision. Variations of relaxation times due to species and strain, different sample handling and different liver damage models, ethionine fatty liver and paracetamol liver necrosis, were investigated. Cell integrity effects were studied on homogenized liver samples. Relaxation time parameters, especially 'main' components T1A and T2A of biexponential model fit, were identified to react very sensitive after tissue damages as well as to cell viability. Thus, investigation of stored liver grafts was performed in order to evaluate the possibility of a rapid liver graft viability testing method for human liver transplantation surgery by 1H-NMR relaxometry. Another series of measurements was performed to investigate the applicability of isoflurane anesthesia for in vivo NMR experiments. This study proved the good appropriateness of isoflurane for that purpose provided that physiological monitoring and individual adjustment of anesthesia are performed. In these investigations it could be revealed that mainly T1A and T2A are influenced by tissue condition and that different information is inherent in these two parameters, with T2A reflecting tissue viability and changes of tissue conditions very sensitively but rather unspecifically in respect to the damage applied. Based on these results the following future applications of 1H-NMR relaxometry are suggested : (1) model investigations, (2) investigation of given pathologies, (3) investigation of basic requirements for in vivo NMR and (4) application in a liver graft viability testing protocol, which seems to be the most important future application of 1H-NMR relaxometry in medicine. (author)

  3. 1H NMR studies of insulin: histidine residues, metal binding, and dissociation in alkaline solution

    The shifts of the H2 histidine B5 and B10 resonances of 2-Zn insulin hexamer were followed in 2H2O by 1H NMR spectroscopy at 270 MHz from pH 9.85 to 7. The two resonances present at high pH, previously assigned to H2 histidine B5 and B10 residues, moved slightly downfield and split into four resonances at pH 8.95 and also at pH 7. By use of a paramagnetic broadening probe (Mn2+) and the addition of Zn2+ to metal-free insulin, it was deduced that the four resonances arose from histidines B10 and B5 in two different magnetic environments, probably either bound to Zn2+ or not bound to Zn2+. The pK' values of the B5 and B10 histidines were determined in 60% 2H2O-40% dioxan, in which insulin was soluble throughout the pH range, to be 7.1 and 6.8, respectively at 37 degrees C. Studies at higher pH indicated that at a concentration level suitable for 1H NMR (approximately 1 mM) at 37 degrees C in 2H2O the 2-Zn hexamer was largely dissociated to dimer at pH 10.3 and to monomer at pH 10.8. Addition of paramagnetic shift probe Ni2+ to metal-free insulin caused changes to the spectrum similar to those produced on addition of diamagnetic Zn2+. Addition of Co2+ gave a different result, but there was no paramagnetic shift of the H2 histidine B10 resonance, probably because of rapid exchange at the binding site. Addition of Cd2+ and of Cd2+ and Ca2+ produced changes that were similar to each other but were different from those observed on addition of Zn2+, probably due to the binding of Cd2+ and Ca2+ at glutamate B13

  4. Primary structure determination of five sialylated oligosaccharides derived from bronchial mucus glycoproteins of patients suffering from cystic fibrosis. The occurrence of the NeuAc alpha(2----3)Gal beta(1----4)[Fuc alpha(1----3)] GlcNAc beta(1----.) structural element revealed by 500-MHz 1H NMR spectroscopy.

    Lamblin, G; Boersma, A; Klein, A; Roussel, P; van Halbeek, H; Vliegenthart, J F

    1984-07-25

    The structure of sialylated carbohydrate units of bronchial mucins obtained from cystic fibrosis patients was investigated by 500-MHz 1H NMR spectroscopy in conjunction with sugar analysis. After subjecting the mucins to alkaline borohydride degradation, sialylated oligosaccharide-alditols were isolated by anion-exchange chromatography and fractionated by high performance liquid chromatography. Five compounds could be obtained in a rather pure state; their structures were established as the following: A-1, NeuAc alpha(2----3)Gal beta(1----4) [Fuc alpha(1----3)]GlcNAc beta(1----3)Gal-NAc-ol; A-2, NeuAc alpha(2----3)Gal beta(1----4)GlcNAc beta(1----6)-[GlcNAc beta (1----3)]GalNAc-o1; A-3, NeuAc alpha(2----3)Gal beta-(1----4)[Fuc alpha(1----3)]GlcNAc beta(1----3)Gal beta(1----3) GalNAc-o1; A-4, NeuAc alpha(2----3)Gal beta(1----4)[Fuc alpha(1----3)]Glc-NAc NAc beta(1----6)[GlcNAc beta(1----3)]GalNAc-o1; A-6,NeuAc alpha-(2----3) Gal beta(1----4)[Fuc alpha(1----3)]GlcNAc beta(1----6)[Gal beta-(1----4) GlcNAc beta(1----3)]GalNAc-o1. The simultaneous presence of sialic acid in alpha(2----3)-linkage to Gal and fucose in alpha(1----3)-linkage to GlcNAc of the same N-acetyllactosamine unit could be adequately proved by high resolution 1H NMR spectroscopy. This sequence constitutes a novel structural element for mucins. PMID:6746638

  5. 1H MR spectroscopy characteristics of cerebral alveolar echinococcosis

    Objective: To investigate the characteristics of proton magnetic resonance spectroscopy (1H MRS) in patients with cerebral alveolar echinococcosis (CAE). Methods: Thirteen patients with 33 lesions proven to be CAE histologically and clinically were examined by conventional MRI and 2D multi-voxel spectroscopy with a 3.0 T double gradient superconductivity magnetic resonance scanner. Concentrations of the metabolites containing N-acetyl-aspartic-acid (NAA), Choline (Cho), Creatine (Cr), lipids and lactic acid (Lip + Lac), myo-Inositol (mI) were detected and the value of Cho/Cr, NAA/Cr, (Lip + Lac)/Cr, mI/Cr were calculated. The values of Cho/Cr, NAA/Cr, (Lip + Lac)/Cr, mI/Cr were compared between the lesions and the contralateral normal brain parenchyma. Statistical analysis was performed using the Wilcoxon signed-rank test. Results: CAE 1H MRS in the lesions was characterized by the decrease of Cho, NAA to varying degrees, and a visible lipid with or without lactate peak. Compared with the control group, the ratio of NAA/Cr was decreased markedly, whereas Cho/Cr, mI/Cr increased mildly and (Lip + Lac)/Cr increased markedly in the lesions. The medians and interquartile ranges of Cho/Cr, NAA/Cr, (Lip + Lac)/Cr and mI/Cr in the lesions were: 1.88 (1.24-2.23), 1.32 (1.07-1.58), 32.96 (24.59-47.30) and 0.91 (0.67-1.08), respectively. The medians and interquartile ranges of Cho/Cr, NAA/Cr, (Lip + Lac)/Cr and mI/Cr of control group were 0.84 (0.704-0.98), 2.00 (1.80-2.18), 0.90 (0.74-0.99) and 0.26 (0.18-0.31), respectively. There were statistically significant differences of the measures between the lesions and the control regions (Z=-5.932, -6.086, -6.946, -6.984, P<0.01). Conclusions: Multi-voxel 1H MRS can reflect pathological characteristics of CAE. 1H MRS provides metabolic information for diagnosis of CAE and may be a supplement to conventional magnetic resonance examination. (authors)

  6. Gene synthesis, bacterial expression, and 1H NMR spectroscopic studies of the rat outer mitochondrial membrane cytochrome b5.

    Rivera, M; Barillas-Mury, C; Christensen, K A; Little, J W; Wells, M A; Walker, F A

    1992-12-01

    The gene coding for the water-soluble domain of the outer mitochondrial membrane cytochrome b5 (OM cytochrome b5) from rat liver has been synthetized and expressed in Escherichia coli. The DNA sequence was obtained by back-translating the known amino acid sequence [Lederer, F., Ghrir, R., Guiard, B., Cortial, S., & Ito, A. (1983) Eur. J. Biochem. 132, 95-102]. The recombinant OM cytochrome b5 was characterized by UV-visible, EPR, and 1H NMR spectroscopy. The UV-visible and EPR spectra of the OM cytochrome b5 are almost identical to the ones obtained from the overexpressed rat microsomal cytochrome b5 [Bodman, S. B. V., Schyler, M. A., Jollie, D. R., & Sligar, S. G. (1986) Proc. Natl. Acad. Sci. U.S.A. 83, 9443-9447]. The one-dimensional 1H NMR spectrum of the OM cytochrome b5 indicates that the rhombic perturbation of the ferric center is essentially identical to that in the microsomal beef, rabbit, chicken, and rat cytochromes b5. Two-dimensional 1H NMR spectroscopy (NOESY) and one-dimensional NOE difference spectroscopy were used to assign the contact-shifted resonances that correspond to each of the two isomers that result from the rotation of the heme around its alpha-gamma-meso axis. The assignment of the resonances allowed the determination of the heme orientation ratio in the OM cytochrome b5, which was found to be 1.0 +/- 0.1. It is noteworthy that the two cytochromes b5 that have similar populations of the two heme isomers (large heme disorder) originate from the rat liver. PMID:1333795

  7. Identification, synthesis and characterization of an unknown process related impurity in eslicarbazepine acetate active pharmaceutical ingredient by LC/ESI–IT/MS, 1H, 13C and 1H–1H COSY NMR

    Saji Thomas

    2014-10-01

    Full Text Available A new impurity was detected during high performance liquid chromatographic (HPLC analysis of eslicarbazepine acetate active pharmaceutical ingredient. The structure of unknown impurity was postulated based on liquid chromatography mass spectrometry using electrospray ionization and ion trap analyzer (LC/ESI–IT/MS analysis. Proposed structure of impurity was unambiguously confirmed by synthesis followed by characterization using 1H, 13C nuclear magnetic resonance spectrometry (NMR, 1H–1H correlation spectroscopy (COSY and infrared spectroscopy (IR. Based on the spectroscopic and spectrometric data, unknown impurity was characterized as 5-carbamoyl-10,11-dihydro-5H-dibenzo[b,f]azepin-10-yl propionate.

  8. An efficient spectra processing method for metabolite identification from 1H-NMR metabolomics data.

    Jacob, Daniel; Deborde, Catherine; Moing, Annick

    2013-06-01

    The spectra processing step is crucial in metabolomics approaches, especially for proton NMR metabolomics profiling. During this step, noise reduction, baseline correction, peak alignment and reduction of the 1D (1)H-NMR spectral data are required in order to allow biological information to be highlighted through further statistical analyses. Above all, data reduction (binning or bucketing) strongly impacts subsequent statistical data analysis and potential biomarker discovery. Here, we propose an efficient spectra processing method which also provides helpful support for compound identification using a new data reduction algorithm that produces relevant variables, called buckets. These buckets are the result of the extraction of all relevant peaks contained in the complex mixture spectra, rid of any non-significant signal. Taking advantage of the concentration variability of each compound in a series of samples and based on significant correlations that link these buckets together into clusters, the method further proposes automatic assignment of metabolites by matching these clusters with the spectra of reference compounds from the Human Metabolome Database or a home-made database. This new method is applied to a set of simulated (1)H-NMR spectra to determine the effect of some processing parameters and, as a proof of concept, to a tomato (1)H-NMR dataset to test its ability to recover the fruit extract compositions. The implementation code for both clustering and matching steps is available upon request to the corresponding author. PMID:23525538

  9. NMR resonance splitting of urea in stretched hydrogels: proton exchange and (1)H/(2)H isotopologues.

    Kuchel, Philip W; Naumann, Christoph; Chapman, Bogdan E; Shishmarev, Dmitry; Håkansson, Pär; Bacskay, George; Hush, Noel S

    2014-10-01

    Urea at ∼12 M in concentrated gelatin gel, that was stretched, gave (1)H and (2)H NMR spectral splitting patterns that varied in a predictable way with changes in the relative proportions of (1)H2O and (2)H2O in the medium. This required consideration of the combinatorics of the two amide groups in urea that have a total of four protonation/deuteration sites giving rise to 16 different isotopologues, if all the atoms were separately identifiable. The rate constant that characterized the exchange of the protons with water was estimated by back-transformation analysis of 2D-EXSY spectra. There was no (1)H NMR spectral evidence that the chiral gelatin medium had caused in-equivalence in the protons bonded to each amide nitrogen atom. The spectral splitting patterns in (1)H and (2)H NMR spectra were accounted for by intra-molecular scalar and dipolar interactions, and quadrupolar interactions with the electric field gradients of the gelatin matrix, respectively. PMID:25241007

  10. 23Na and 1H NMR Relaxometry of Shale at High Magnetic Field

    Yang, Donghan

    2016-01-01

    Formation evaluation of unconventional reservoirs is challenging due to the coexistence of different phases such as kerogen, bitumen, movable and bound light hydrocarbon and water. Current low-frequency (0.05 T) nuclear magnetic resonance (NMR) laboratory and logging methods are incapable of quantitatively separating the different phases. We demonstrate the utility of high-field (9 T) NMR 2D T1-T2 measurements for separating hydrocarbon and the clay-interacting aqueous phases in shale based on the difference in the frequency dependence of the spin-lattice relaxation time. Furthermore, we demonstrate 23Na NMR as a promising complementary technique to conventional 1H NMR for shale fluid typing, taking advantage of the fact that sodium ions are only present in the aqueous phase. We validate high-field (9 T) 23Na-1H NMR relaxometry for assessing brine-filled porosity and brine salinity in various porous materials, including porous glass, conventional rocks, clays, and shale, and apply it for differentiating hydro...

  11. NMR Spectroscopy and Its Value: A Primer

    Veeraraghavan, Sudha

    2008-01-01

    Nuclear magnetic resonance (NMR) spectroscopy is widely used by chemists. Furthermore, the use of NMR spectroscopy to solve structures of macromolecules or to examine protein-ligand interactions is popular. Yet, few students entering graduate education in biological sciences have been introduced to this method or its utility. Over the last six…

  12. 15N and 1H NMR evidence for multiple conformations of the complex of dihydrofolate reductase with its substrate, folate

    The binding of folate to Lactobacillus casei dihydrofolate reductase in the presence and absence of NADP+ has been studied by 15N NMR, using [5-15N]folate. In the presence of NADP+, three separate signals were observed for the single 15N atom, in agreement with our earlier evidence from 1H and 13C NMR for multiple conformations of this complex. The 15N spectra of the binary enzyme-folate complex provide evidence for the first time that this complex also exists in at least two conformational states. This is confirmed by the observation of two separate resonances for the 7-proton of bound folate, located by two-dimensional exchange spectroscopy. 15 refs.; 3 figs.; 1 table

  13. MetaboHunter: an automatic approach for identification of metabolites from 1H-NMR spectra of complex mixtures

    Culf Adrian

    2011-10-01

    Full Text Available Abstract Background One-dimensional 1H-NMR spectroscopy is widely used for high-throughput characterization of metabolites in complex biological mixtures. However, the accurate identification of individual compounds is still a challenging task, particularly in spectral regions with higher peak densities. The need for automatic tools to facilitate and further improve the accuracy of such tasks, while using increasingly larger reference spectral libraries becomes a priority of current metabolomics research. Results We introduce a web server application, called MetaboHunter, which can be used for automatic assignment of 1H-NMR spectra of metabolites. MetaboHunter provides methods for automatic metabolite identification based on spectra or peak lists with three different search methods and with possibility for peak drift in a user defined spectral range. The assignment is performed using as reference libraries manually curated data from two major publicly available databases of NMR metabolite standard measurements (HMDB and MMCD. Tests using a variety of synthetic and experimental spectra of single and multi metabolite mixtures show that MetaboHunter is able to identify, in average, more than 80% of detectable metabolites from spectra of synthetic mixtures and more than 50% from spectra corresponding to experimental mixtures. This work also suggests that better scoring functions improve by more than 30% the performance of MetaboHunter's metabolite identification methods. Conclusions MetaboHunter is a freely accessible, easy to use and user friendly 1H-NMR-based web server application that provides efficient data input and pre-processing, flexible parameter settings, fast and automatic metabolite fingerprinting and results visualization via intuitive plotting and compound peak hit maps. Compared to other published and freely accessible metabolomics tools, MetaboHunter implements three efficient methods to search for metabolites in manually curated

  14. The (1) H NMR spectrum of pyrazole in a nematic phase.

    Provasi, Patricio; Jimeno, María Luisa; Alkorta, Ibon; Reviriego, Felipe; Elguero, José; Jokisaari, Jukka

    2016-08-01

    The experimental (1) H nuclear magnetic resonance (NMR) spectrum of 1H-pyrazole was recorded in thermotropic nematic liquid crystal N-(p-ethoxybenzylidene)-p-butylaniline (EBBA) within the temperature range of 299-308 K. Two of three observable dipolar DHH -couplings appeared to be equal at each temperature because of fast prototropic tautomerism. Analysis of the Saupe orientational order parameters using fixed geometry determined by computations and experimental dipolar couplings results in a situation in which the molecular orientation relative to the magnetic field (and the liquid crystal director) can be described exceptionally by a single parameter. Copyright © 2016 John Wiley & Sons, Ltd. PMID:26947581

  15. (1)H-NMR-based discrimination of thermal and vinegar treated ginseng roots.

    Kim, So-Hyun; Hyun, Sun-Hee; Yang, Seung-Ok; Choi, Hyung-Kyoon; Lee, Boo-Yong

    2010-08-01

    To investigate the changes in nonvolatile metabolites of thermal and/or vinegar treated ginseng (TVG), samples prepared using various treatment conditions were analyzed using an (1)H-NMR-based metabolomics technique. The processing conditions of the ginseng in this study were 100, 140, and 180 degrees C with and without vinegar and the duration of exposure to each temperature was 10, 30, and 50 min, respectively. There was a clear separation in the score plots among various treatment conditions. Major compounds contributing to the separation of 50% methanol extracts of TVG with various process conditions were valine, lactate, alanine, arginine, glucose, fructose, and sucrose. As temperature increased, valine, arginine, glucose, fructose, and sucrose concentrations decreased, whereas lactate, glucose, and fructose increased in the vinegar-treated samples compared to non-vinegar-treated samples. The present study suggests the usefulness of an (1)H-NMR-based metabolomics approach to discriminate TVG samples, subjected to different processing conditions. PMID:20722913

  16. Evaluation of saffron (Crocus sativus L.) adulteration with plant adulterants by (1)H NMR metabolite fingerprinting.

    Petrakis, Eleftherios A; Cagliani, Laura R; Polissiou, Moschos G; Consonni, Roberto

    2015-04-15

    In the present work, a preliminary study for the detection of adulterated saffron and the identification of the adulterant used by means of (1)H NMR and chemometrics is reported. Authentic Greek saffron and four typical plant-derived materials utilised as bulking agents in saffron, i.e., Crocus sativus stamens, safflower, turmeric, and gardenia were investigated. A two-step approach, relied on the application of both OPLS-DA and O2PLS-DA models to the (1)H NMR data, was adopted to perform authentication and prediction of authentic and adulterated saffron. Taking into account the deficiency of established methodologies to detect saffron adulteration with plant adulterants, the method developed resulted reliable in assessing the type of adulteration and could be viable for dealing with extensive saffron frauds at a minimum level of 20% (w/w). PMID:25466103

  17. 1H NMR study of thermotropic phase transition in aqueous polymer solutions

    Spěváček, Jiří; Hanyková, L.

    Poznan : Adam Mickiewicz University, Poznan, 2002 - (Garsztka, M.; Pisula, D.; Wegorowska, W.). s. 237 [Congress AMPERE: Magnetic Resonance and Related Phenomena /31./. 15.07.2002-19.07.2002, Poznan] R&D Projects: GA AV ČR KSK4050111 Grant ostatní: GA UK(CZ) 164/20B Keywords : 1H NMR * thermotropic phase transition * poly(vinyl methyl ether)/D2O solutions Subject RIV: CD - Macromolecular Chemistry

  18. Application of cryoprobe 1H nuclear magnetic resonance spectroscopy and multivariate analysis for the verification of corsican honey.

    Donarski, James A; Jones, Stephen A; Charlton, Adrian J

    2008-07-23

    Proton nuclear magnetic resonance spectroscopy ((1)H NMR) and multivariate analysis techniques have been used to classify honey into two groups by geographical origin. Honey from Corsica (Miel de Corse) was used as an example of a protected designation of origin product. Mathematical models were constructed to determine the feasibility of distinguishing between honey from Corsica and that from other geographical locations in Europe, using (1)H NMR spectroscopy. Honey from 10 different regions within five countries was analyzed. (1)H NMR spectra were used as input variables for projection to latent structures (PLS) followed by linear discriminant analysis (LDA) and genetic programming (GP). Models were generated using three methods, PLS-LDA, two-stage GP, and a combination of PLS and GP (PLS-GP). The PLS-GP model used variables selected by PLS for subsequent GP calculations. All models were generated using Venetian blind cross-validation. Overall classification rates for the discrimination of Corsican and non-Corsican honey of 75.8, 94.5, and 96.2% were determined using PLS-LDA, two-stage GP, and PLS-GP, respectively. The variables utilized by PLS-GP were related to their (1)H NMR chemical shifts, and this led to the identification of trigonelline in honey for the first time. PMID:18564849

  19. Complete 1H and 13C NMR assignments and anti fungal activity of two 8-hydroxy flavonoids in mixture

    A mixture of the two new flavonols 8-hydroxy-3, 4', 5, 6, 7-pentamethoxyflavone (1) and 8-hydroxy-3, 3', 4', 5, 6, 7-hexamethoxyflavone (2) was isolated from a commercial sample of Citrus aurantifolia. An array of one- (1H NMR, {1H} -13C NMR, and APT-13C NMR) and two-dimensional NMR techniques (COSY, NOESY, HMQC and HMBC) was used to achieve the structural elucidation and the complete 1H and 13C chemical shift assignments of these natural compounds. In addition, the antifungal activity of these compounds against phytopathogenic and human pathogenic fungi was investigated. (author)

  20. 1H NMR- based metabolomics approaches as non- invasive tools for diagnosis of endometriosis

    Negar Ghazi

    2016-01-01

    Full Text Available Background: So far, non-invasive diagnostic approaches such as ultrasound, magnetic resonance imaging, or blood tests do not have sufficient diagnostic power for endometriosis disease. Lack of a non-invasive diagnostic test contributes to the long delay between onset of symptoms and diagnosis of endometriosis. Objective: The present study focuses on the identification of predictive biomarkers in serum by pattern recognition techniques and uses partial least square discriminant analysis, multi-layer feed forward artificial neural networks (ANNs and quadratic discriminant analysis (QDA modeling tools for the early diagnosis of endometriosis in a minimally invasive manner by 1H- NMR based metabolomics. Materials and Methods: This prospective cohort study was done in Pasteur Institute, Iran in June 2013. Serum samples of 31 infertile women with endometriosis (stage II and III who confirmed by diagnostic laparoscopy and 15 normal women were collected and analyzed by nuclear magnetic resonance spectroscopy. The model was built by using partial least square discriminant analysis, QDA, and ANNs to determine classifier metabolites for early prediction risk of disease. Results: The levels of 2- methoxyestron, 2-methoxy estradiol, dehydroepiandrostion androstendione, aldosterone, and deoxy corticosterone were enhanced significantly in infertile group. While cholesterol and primary bile acids levels were decreased. QDA model showed significant difference between two study groups. Positive and negative predict value levels obtained about 71% and 78%, respectively. ANNs provided also criteria for detection of endometriosis. Conclusion: The QDA and ANNs modeling can be used as computational tools in noninvasive diagnose of endometriosis. However, the model designed by QDA methods is more efficient compared to ANNs in diagnosis of endometriosis patients.

  1. 1H NMR- based metabolomics approaches as non- invasive tools for diagnosis of endometriosis

    Ghazi, Negar; Arjmand, Mohammad; Akbari, Ziba; Mellati, Ali Owsat; Saheb-Kashaf, Hamid; Zamani, Zahra

    2016-01-01

    Background: So far, non-invasive diagnostic approaches such as ultrasound, magnetic resonance imaging, or blood tests do not have sufficient diagnostic power for endometriosis disease. Lack of a non-invasive diagnostic test contributes to the long delay between onset of symptoms and diagnosis of endometriosis. Objective: The present study focuses on the identification of predictive biomarkers in serum by pattern recognition techniques and uses partial least square discriminant analysis, multi-layer feed forward artificial neural networks (ANNs) and quadratic discriminant analysis (QDA) modeling tools for the early diagnosis of endometriosis in a minimally invasive manner by 1H- NMR based metabolomics. Materials and Methods: This prospective cohort study was done in Pasteur Institute, Iran in June 2013. Serum samples of 31 infertile women with endometriosis (stage II and III) who confirmed by diagnostic laparoscopy and 15 normal women were collected and analyzed by nuclear magnetic resonance spectroscopy. The model was built by using partial least square discriminant analysis, QDA, and ANNs to determine classifier metabolites for early prediction risk of disease. Results: The levels of 2- methoxyestron, 2-methoxy estradiol, dehydroepiandrostion androstendione, aldosterone, and deoxy corticosterone were enhanced significantly in infertile group. While cholesterol and primary bile acids levels were decreased. QDA model showed significant difference between two study groups. Positive and negative predict value levels obtained about 71% and 78%, respectively. ANNs provided also criteria for detection of endometriosis. Conclusion: The QDA and ANNs modeling can be used as computational tools in noninvasive diagnose of endometriosis. However, the model designed by QDA methods is more efficient compared to ANNs in diagnosis of endometriosis patients.

  2. 1H NMR- based metabolite profiling of tropane alkaloids in Duboisia spec.

    Ullrich, Sophie Friederike

    2016-07-01

    Full Text Available Duboisia R.Br. (Solanaceae is the main source of the tropane alkaloid scopolamine, which is an important precursor of various active pharmaceutical ingredients due to its anticholinergic properties. As only little is known about the metabolite composition among the different species, NMRbased metabolic profiling was done in order to elucidate primary and secondary metabolism in Duboisia especially focusing on the tropane alkaloid pathway. For this purpose, plants of five different genotypes (Duboisia myoporoides, D. leichardtii and hybrids of D. myoporoides and D. leichhardtii were cultivated under strictly controlled conditions in climate chambers, leaf and root extracts were prepared and measured via 1H NMR. 14 different metabolites could be identified using 1D- and 2D-NMR techniques. Principal component analysis of the NMR data allowed a clear distinction between Duboisia hybrids and the wild types, which could be again subgrouped in D. myoporoides and D. leichhardtii, based on the metabolites identified.

  3. Complete 1H NMR assignments of pyrrolizidine alkaloids and a new eudesmanoid from Senecio polypodioides.

    Villanueva-Cañongo, Claudia; Pérez-Hernández, Nury; Hernández-Carlos, Beatriz; Cedillo-Portugal, Ernestina; Joseph-Nathan, Pedro; Burgueño-Tapia, Eleuterio

    2014-05-01

    Chemical investigation of the aerial parts of Senecio polypodioides lead to the isolation of the new eudesmanoid 1β-angeloyloxyeudesm-7-ene-4β,9α-diol (1) and the known dirhamnosyl flavonoid lespidin (3), while from roots, the known 7β-angeloyloxy-1-methylene-8α-pyrrolizidine (5) and sarracine N-oxide (6), as well as the new neosarracine N-oxide (8), were obtained. The structure of 1 and 8 was elucidated by spectral means. Complete assignments of the (1)H NMR data for 5, 6, sarracine (7), and 8 were made using one-dimensional and two-dimensional NMR experiments and by application of the iterative full spin analysis of the PERCH NMR software. PMID:24574143

  4. Translational diffusion in paramagnetic liquids by 1H NMR relaxometry: Nitroxide radicals in solution

    Kruk, D.; Korpała, A.; Kubica, A.; Meier, R.; Rössler, E. A.; Moscicki, J.

    2013-01-01

    For nitroxide radicals in solution one can identify three frequency regimes in which 1H spin-lattice relaxation rate of solvent molecules depend linearly on square root of the 1H resonance frequency. Combining a recently developed theory of nuclear (proton) spin-lattice relaxation in solutions of nitroxide radicals [D. Kruk et al., J. Chem. Phys. 137, 044512 (2012)], 10.1063/1.4736854 with properties of the spectral density function associated with translational dynamics, relationships between the corresponding linear changes of the relaxation rate (for 14N spin probes) and relative translational diffusion coefficient of the solvent and solute molecules have been derived (in analogy to 15N spin probes [E. Belorizky et al., J. Phys. Chem. A 102, 3674 (1998)], 10.1021/jp980397h). This method allows a simple and straightforward determination of diffusion coefficients in spin-labeled systems, by means of 1H nuclear magnetic resonance (NMR) relaxometry. The approach has thoroughly been tested by applying to a large set of experimental data—1H spin-lattice relaxation dispersion results for solutions of different viscosity (decalin, glycerol, propylene glycol) of 14N and 15N spin probes. The experiments have been performed versus temperature (to cover a broad range of translational diffusion coefficients) using field cycling spectrometer which covers three decades in 1H resonance frequency, 10 kHz-20 MHz. The limitations of NMR relaxometry caused by the time scale of the translational dynamics as well as electron spin relaxation have been discussed. It has been shown that for spin-labeled systems NMR relaxometry gives access to considerably faster diffusion processes than for diamagnetic systems.

  5. High resolution 1H NMR spectroscopic studies of the metabolism and excretion of ampicillin in rats and amoxycillin in rats and man.

    Connor, S C; Everett, J R; Jennings, K R; Nicholson, J K; Woodnutt, G

    1994-02-01

    High resolution proton nuclear magnetic resonance (1H NMR) spectroscopy has been used to investigate the metabolism and urinary excretion of the aminopenicillins, ampicillin and amoxycillin, in rats and of amoxycillin in man. 1H NMR resonances of the aminopenicillins, together with those for their 5R, 6R and 5S, 6R penicilloic acids and diketopiperazine metabolites were detected, assigned and quantified in urine samples with the aid of spin-echo NMR techniques. The dimer of amoxycillin was detected in rat urine for the first time together with novel drug-related resonances assigned to amoxycillin carbamate. Quantitative 1H NMR spectroscopic results were consistent with HPLC and microbiological data considering that only single measurements were recorded. Due to the short analysis time and simple sample preparation, NMR was particularly useful for studying the metabolism of the aminopenicillins for which sample degradation poses analytical problems. The non-invasive character of 1H NMR spectroscopic analysis of urine also provided unique information on a reversible reaction between amoxycillin and bicarbonate, an endogenous urinary metabolite. PMID:8021801

  6. Complete {sup 1}H and {sup 13}C NMR structural assignments for a group of four goyazensolide-type furanoheliangolides

    Soares, Ana Carolina Ferreira; Silva, Aline Nazare; Matos, Priscilla Mendonca; Silva, Eder Henrique da; Heleno, Vladimir Constantino Gomes [Universidade de Franca, Franca, SP (Brazil). Nucleo de Pesquisas em Ciencias Exatas e Tecnologicas; Lopes, Norberto Peporine; Lopes, Joao Luis Callegari [Universidade de Sao Paulo (FCFRP/USP), Ribeirao Preto, SP (Brazil). Fac. de Ciencias Farmaceuticas de Ribeirao Preto. Dept. de Quimica e Fisica; Sass, Daiane Cristina, E-mail: vheleno_05@yahoo.com.br [Universidade de Sao Paulo (FFCLRP/USP), Ribeirao Preto, SP (Brazil). Fac. de Filosofia, Ciencias e Letras de Ribeirao Preto. Dept. de Quimica

    2012-07-01

    Four goyazensolide-type sesquiterpene lactones - lychnofolide, centratherin, goyazensolide and goyazensolide acetate - were thoroughly studied by NMR experimental techniques. {sup 1}H NMR, {sup 13}C NMR {l_brace}{sup 1}H{r_brace}, COSY, HMQC, HMBC, J-res. and NOE experiments were performed to provide the needed structural information. Complete and unequivocal assignment, including the determination of all multiplicities, was obtained for each structure and the data collections are presented in tables (author)

  7. Complete 1H and 13C NMR structural assignments for a group of four goyazensolide-type furanoheliangolides

    Four goyazensolide-type sesquiterpene lactones - lychnofolide, centratherin, goyazensolide and goyazensolide acetate - were thoroughly studied by NMR experimental techniques. 1H NMR, 13C NMR {1H}, COSY, HMQC, HMBC, J-res. and NOE experiments were performed to provide the needed structural information. Complete and unequivocal assignment, including the determination of all multiplicities, was obtained for each structure and the data collections are presented in tables (author)

  8. Structure and equilibria of Ca 2+-complexes of glucose and sorbitol from multinuclear ( 1H, 13C and 43Ca) NMR measurements supplemented with molecular modelling calculations

    Pallagi, A.; Dudás, Cs.; Csendes, Z.; Forgó, P.; Pálinkó, I.; Sipos, P.

    2011-05-01

    Ca 2+-complexation of D-glucose and D-sorbitol have been investigated with the aid of multinuclear ( 1H, 13C and 43Ca) NMR spectroscopy and ab initio quantum chemical calculations. Formation constants of the forming 1:1 complexes have been estimated from one-dimensional 13C NMR spectra obtained at constant ionic strength (1 M NaCl). Binding sites were identified from 2D 1H- 43Ca NMR spectra. 2D NMR measurements and ab initio calculations indicated that Ca 2+ ions were bound in a tridentate manner via the glycosidic OH, the ethereal oxygen in the ring and the OH on the terminal carbon for the α- and β-anomers of glucose and for sorbitol simultaneous binding of four hydroxide moieties (C1, C2, C4 and C6) was suggested.

  9. Quantification of dextrose in model solution by 1H MR spectroscopy at 1.5T

    To evaluate the feasibility of proton magnetic resonance spectroscopy (1H-MRS) using a 1.5T magnetic resonance (MR) imager for quantification of the contents of model solutions. We prepared model solutions of dextrose +water and dextrose +water + ethanol at dextrose concentrations of 0.01% to 50% and 0.01% to 20%, respectively. Using these solutions and a 1.5T MR imager together with a high-resolution nuclear magnetic resonance (NMR) spectroscope, we calculated the ratios of dextrose to water peak, (dextrose +ethanol) to water peak, and (dextrose + ethanol) to ethanol peak, as seen on MR and NMR spectra, analysing the relationships between dextrose concentration and the ratios of peaks, and between the ratios of the peaks seen on MR spectra and those seen on NMR spectra. Changes in the ratios between dextrose concentration and dextrose to water peak, (dextrose + ethanol) to water peak and (dextrose + ethanol) to ethanol peak, as seen on MR spectra, were statistically significant, and there was good linear regression. There was also close correlation between the ratios of the observed on MR and NMR spectra. The results depict the quantification of dextrose concentration according to the ratios of spectral peaks obtained by proton MRS at 1.5T. Using proton MRS at 1.5T, and on the basis of the ratios of spectcal peaks, it was possible to quantify the concentration of dextrose in model solutions of dextrose + water and dextrose + water+ ethanol. The results of this study suggest that for quantifying the contents of biofluids, the use of low-tesla 1H-MRS is feasible

  10. Xanthan Gum Removal for 1H-NMR Analysis of the Intracellular Metabolome of the Bacteria Xanthomonas axonopodis pv. citri 306

    Vanessa R. Pegos

    2014-04-01

    Full Text Available Xanthomonas is a genus of phytopathogenic bacteria, which produces a slimy, polysaccharide matrix known as xanthan gum, which involves, protects and helps the bacteria during host colonization. Although broadly used as a stabilizer and thickener in the cosmetic and food industries, xanthan gum can be a troubling artifact in molecular investigations due to its rheological properties. In particular, a cross-reaction between reference compounds and the xanthan gum could compromise metabolic quantification by NMR spectroscopy. Aiming at an efficient gum extraction protocol, for a 1H-NMR-based metabolic profiling study of Xanthomonas, we tested four different interventions on the broadly used methanol-chloroform extraction protocol for the intracellular metabolic contents observation. Lower limits for bacterial pellet volumes for extraction were also probed, and a strategy is illustrated with an initial analysis of X. citri’s metabolism by 1H-NMR spectroscopy.

  11. Identification of fucans from four species of sea cucumber by high temperature 1H NMR

    Wu, Nian; Chen, Shiguo; Ye, Xingqian; Li, Guoyun; Yin, Li'ang; Xue, Changhu

    2014-10-01

    Acidic polysaccharide, which has various biological activities, is one of the most important components of sea cucumber. In the present study, crude polysaccharide was extracted from four species of sea cucumber from three different geographical zones, Pearsonothuria graeffei ( Pg) from Indo-Pacific, Holothuria vagabunda ( Hv) from Norwegian Coast, Stichopus tremulu ( St) from Western Indian Ocean, and Isostichopus badionotu ( Ib) from Western Atlantic. The polysaccharide extract was separated and purified with a cellulose DEAE anion-exchange column to obtain corresponding sea cucumber fucans (SC-Fucs). The chemical property of these SC-Fucs, including molecular weight, monosaccharide composition and sulfate content, was determined. Their structure was compared simply with fourier infrared spectrum analyzer and identified with high temperature 1H nuclear magnetic resonance spectrum analyzer (NMR) and room temperature 13C NMR. The results indicated that Fuc- Pg obtained from the torrid zone mainly contained 2,4-O-disulfated and non-sulfated fucose residue, whereas Fuc- Ib from the temperate zone contained non-, 2-O- and 2,4-O-disulfated fucose residue; Fuc- St from the frigid zone and Fuc- Hv from the torrid zone contained mainly non-sulfated fucose residue. The proton of SC-Fucs was better resolved via high temperature 1H NMR than via room temperature 1H NMR. The fingerprint of sea cucumber in different sea regions was established based on the index of anomer hydrogen signal in SC-Fucs. Further work will help to understand whether there exists a close relationship between the geographical area of sea cucumber and the sulfation pattern of SC-Fucs.

  12. Interleaved localized 1H/31P nuclear magnetic resonance spectroscopy of skeletal muscle

    Nuclear magnetic resonance (NMR) has been used as a spectroscopic method in physics and chemistry before it was developed to become a diagnostic imaging tool in medicine. When NMR spectroscopy is applied to human tissue, metabolism can be studied in normal physiological and pathological states in vivo. Metabolite concentrations and rates can be monitored dynamically and with localization of a defined region of interest. The 'window' which is opened for observation, i.e. which quantities are measured, depends on the nucleus used for RF excitation. Mechanisms of adenosine tri-phosphate (ATP) resynthesis, as a direct source of energy for muscle contraction, are phosphocreatine (PCr) splitting, glycolysis, beta-oxidation and, finally, oxidative phosphorylation. Whilst the dependency of these processes' fractional contribution to muscular energy supply on exercise type and duration is well known, quantitative models of the regulating mechanisms involved are still subject of current research. A large fraction of the established knowledge about metabolism is based on biochemical analysis of tissue acquired invasively (e.g. microdialysis and open-flow microperfusion) or representing averaged metabolic concentrations for the whole body (via serum metabolites or gas exchange analysis). Localized NMR spectroscopy, however, is capable of non-invasively acquiring time-resolved data from a defined volume of interest, in vivo. In contrast to the vast majority of MRS studies investigating metabolism, where spectra of a single nucleus (commonly 1H, 31P or 13C) were acquired or several MR spectra with different nuclei were measured in separate experiments, this work opens an additional 'window' on muscle metabolism by interleaved localized acquisition of 1H and 31P NMR spectra from human calf muscle in vivo, during rest, exercise and recovery, in a single experiment. Using this technique, the time courses of the concentrations of phosphocreatine, inorganic phosphate (Pi), ATP, total

  13. Integration of screening and identifying ligand(s) from medicinal plant extracts based on target recognition by using NMR spectroscopy

    sprotocols

    2015-01-01

    Authors: Yalin Tang, Qian Shang, Junfeng Xiang, Qianfan Yang, Qiuju Zhou, Lin Li, Hong Zhang, Qian Li, Hongxia Sun, Aijiao Guan, Wei Jiang & Wei Gai ### Abstract This protocol presents the screening of ligand(s) from medicinal plant extracts based on target recognition by using NMR spectroscopy. A detailed description of sample preparation and analysis process is provided. NMR spectroscopies described here are 1H NMR, diffusion-ordered spectroscopy (DOSY), relaxation-edited NMR, ...

  14. Discriminating binding and positioning of amphiphiles to lipid bilayers by 1H NMR

    The binding and positioning in lipid bilayers of three well-known drugs--imipramine, nicotine, and caffeine--have been studied using 1H NMR. The membrane model system consisted of 'fast-tumbling' lipid bicelles, in which a bilayered lipid domain, composed of the unsaturated lipid, 1,2-dimyristelaidoyl-sn-glycero-3-phosphocholine (DMLPC) was surrounded by a rim of deuterated detergent-like lipids, consisting of 1,2-dihexanoyl-sn-glycero-3-phosphocholine (DHPC-d22). Binding and immersion depth information was obtained by three experiments. (1) 1H chemical shift perturbations, upon transfer of the amphiphiles from water to a bicelle mixture, were used to estimate regions of the amphiphiles that interact with the membrane. (2) Water contact to resolvable protons was measured through a Nuclear Overhauser Effect (NOE) between water and resolvable drug and lipid resonances. In the case of both lipids and membrane bound drugs, positive NOEs with large cross-relaxation rates were measured for most resonances originating from the membrane hydrophilic region, while negative NOEs were observed predominantly to resonances in the hydrophobic region of the membrane. (3) 1H NMR measurements of oxygen-induced (paramagnetic) spin-lattice relaxation rates, which are known to increase with membrane immersion depth, were used to corroborate conclusions based on chemical shift perturbations and water-ligand NOEs

  15. NMR spectroscopy assists synthetic fuels research

    Cookson, D.J.; Smith, B.E.

    1983-01-01

    NMR spectroscopy has proved to be a useful and versatile technique for the study of synthetic fuels feedstocks, catalysts, process intermediates and final products. Some applications of the technique to coal and gas conversion research are illustrated and discussed.

  16. Synergistic effect of the simultaneous chemometric analysis of {sup 1}H NMR spectroscopic and stable isotope (SNIF-NMR, {sup 18}O, {sup 13}C) data: Application to wine analysis

    Monakhova, Yulia B., E-mail: yul-monakhova@mail.ru [Chemisches und Veterinäruntersuchungsamt (CVUA) Karlsruhe, Weissenburger Strasse 3, Karlsruhe 76187 (Germany); Bruker Biospin GmbH, Silberstreifen, Rheinstetten 76287 (Germany); Department of Chemistry, Saratov State University, Astrakhanskaya Street 83, Saratov 410012 (Russian Federation); Godelmann, Rolf [Chemisches und Veterinäruntersuchungsamt (CVUA) Karlsruhe, Weissenburger Strasse 3, Karlsruhe 76187 (Germany); Hermann, Armin [Landesuntersuchungsamt -Institut für Lebensmittelchemie und Arzneimittelprüfung, Emy-Roeder-Straße 1, Mainz 55129 (Germany); Kuballa, Thomas [Chemisches und Veterinäruntersuchungsamt (CVUA) Karlsruhe, Weissenburger Strasse 3, Karlsruhe 76187 (Germany); Cannet, Claire; Schäfer, Hartmut; Spraul, Manfred [Bruker Biospin GmbH, Silberstreifen, Rheinstetten 76287 (Germany); Rutledge, Douglas N. [AgroParisTech, UMR 1145, Ingénierie Procédés Aliments, 16 rue Claude Bernard, Paris F-75005 (France)

    2014-06-23

    Highlights: • {sup 1}H NMR profilings of 718 wines were fused with stable isotope analysis data (SNIF-NMR, {sup 18}O, {sup 13}C). • The best improvement was obtained for prediction of the geographical origin of wine. • Certain enhancement was also obtained for the year of vintage (from 88 to 97% for {sup 1}H NMR to 99% for the fused data). • Independent component analysis was used as an alternative chemometric tool for classification. - Abstract: It is known that {sup 1}H NMR spectroscopy represents a good tool for predicting the grape variety, the geographical origin, and the year of vintage of wine. In the present study we have shown that classification models can be improved when {sup 1}H NMR profiles are fused with stable isotope (SNIF-NMR, {sup 18}O, {sup 13}C) data. Variable selection based on clustering of latent variables was performed on {sup 1}H NMR data. Afterwards, the combined data of 718 wine samples from Germany were analyzed using linear discriminant analysis (LDA), partial least squares-discriminant analysis (PLS-DA), factorial discriminant analysis (FDA) and independent components analysis (ICA). Moreover, several specialized multiblock methods (common components and specific weights analysis (ComDim), consensus PCA and consensus PLS-DA) were applied to the data. The best improvement in comparison with {sup 1}H NMR data was obtained for prediction of the geographical origin (up to 100% for the fused data, whereas stable isotope data resulted only in 60–70% correct prediction and {sup 1}H NMR data alone in 82–89% respectively). Certain enhancement was obtained also for the year of vintage (from 88 to 97% for {sup 1}H NMR to 99% for the fused data), whereas in case of grape varieties improved models were not obtained. The combination of {sup 1}H NMR data with stable isotope data improves efficiency of classification models for geographical origin and vintage of wine and can be potentially used for other food products as well.

  17. Adsorption mechanism at the molecular level between polymers and uremic octapeptide by the 2D 1H NMR Technique.

    Li, Guohua; Li, Jihong; Wang, Wei; Yang, Mei; Zhang, Yuanwei; Sun, Pingchuan; Yuan, Zhi; He, Binglin; Yu, Yaoting

    2006-06-01

    To remove uremic octapeptide from the blood stream of uremic patients, various modified polyacylamide cross-linked absorbents were prepared. Adsorption experiments showed these absorbents have significant differences in adsorption capacity to the target peptide. In this paper, two-dimension proton nuclear magnetic resonance (2D 1H NMR) spectroscopy was used to investigate the interaction mechanism between the peptide and the adsorbents. Because of the insolubility of the absorbent, some soluble linear polymers with the same functional groups as the absorbents were employed as the model adsorbents in 2D 1H NMR. The preferred binding site for the peptide and polymers was identified to be at the C-terminal carboxyl group of the octapeptide via chemical shift perturbation effects. In this study, we found that hydrogen bonding, electrostatic, and hydrophobic interactions all play a role in the interaction force but had different contributions. Especially, the great chemical shift changes of the aromatic amino acid residues (Trp) during the interaction between butyl-modified polyacrylamide and octapeptide suggested the hydrophobic interaction, incorporated with the electrostatic force, played an important role in the binding reaction in aqueous solutions. This information not only rationally explained the results of the adsorption experiments, but also identified the effective binding site and mechanism, and shall provide a structural basis for designing better affinity-type adsorbents for the target peptide. PMID:16768402

  18. sup 1 H NMR studies of hydrogen and carbon monoxide chemisorption on the EUROPt-1 catalyst

    Bouyssy, P X

    2001-01-01

    possible carbon monoxide-induced reorganisation of the surface sites available for hydrogen, following a carbon monoxide precoverage above a critical level. It also shows that carbon monoxide blocks hydrogen adsorption but not in the manner expected. No desorption of carbon monoxide was observed with gas phase infrared experiments even at hydrogen coverages approaching saturation. Secondly, to further the understanding of the dynamics of adsorbed hydrogen exchanging between the strongly bound and the weakly bound sites, proton relaxation NMR experiments were undertaken. T sub 1 and T sub 1 subrho measurements were carried out as a function of hydrogen coverage at room temperature and as a function of temperature at fixed hydrogen coverage. These experiments proved to be experimentally challenging and the data obtained do not show a clear enough trend to reach a significant conclusion as was firstly expected. A specially designed sup 1 H NMR probe, capable of holding a large quantity of catalyst sample for in ...

  19. Complete sequence-specific 1H NMR assignments for human insulin

    Solvent conditions where human insulin could be studied by high-resolution NMR were determined. Both low pH and addition of acetonitrile were required to overcome the protein's self-association and to obtain useful spectra. Two hundred eighty-six 1H resonances were located and assigned to specific sites on the protein by using two-dimensional NMR methods. The presence and position of numerous dNN sequential NOE's indicate that the insulin conformation seen in crystallographic studies is largely retained under these solution conditions. Slowly exchanging protons were observed for seven backbone amide protons and were assigned to positions A15 and A16 and to positions B15-B19. These amides all occur within helical regions of the protein

  20. Complete sequence-specific sup 1 H NMR assignments for human insulin

    Kline, A.D.; Justice, R.M. Jr. (Eli Lilly and Co., Indianapolis, IN (USA))

    1990-03-27

    Solvent conditions where human insulin could be studied by high-resolution NMR were determined. Both low pH and addition of acetonitrile were required to overcome the protein's self-association and to obtain useful spectra. Two hundred eighty-six {sup 1}H resonances were located and assigned to specific sites on the protein by using two-dimensional NMR methods. The presence and position of numerous d{sub NN} sequential NOE's indicate that the insulin conformation seen in crystallographic studies is largely retained under these solution conditions. Slowly exchanging protons were observed for seven backbone amide protons and were assigned to positions A15 and A16 and to positions B15-B19. These amides all occur within helical regions of the protein.

  1. 1H, 13C and 15N NMR assignments of phenazopyridine derivatives.

    Burgueño-Tapia, Eleuterio; Mora-Pérez, Yolanda; Morales-Ríos, Martha S; Joseph-Nathan, Pedro

    2005-03-01

    Phenazopyridine hydrochloride (1), a drug in clinical use for many decades, and some derivatives were studied by one- and two-dimensional (1)H, (13)C and (15)N NMR methodology. The assignments, combined with DFT calculations, reveal that the preferred protonation site of the drug is the pyridine ring nitrogen atom. The chemoselective acetylation of phenazopyridine (2) and its influence on the polarization of the azo nitrogen atoms were evidenced by the (15)N NMR spectra. Molecular calculations of the phenazopyridines 2-4 show that the pyridine and phenyl groups are oriented in an antiperiplanar conformation with intramolecular hydrogen bonding between the N-b atom and the C-2 amino group preserving the E-azo stereochemistry. PMID:15625718

  2. Detection and quantification of phenolic compounds in olive oil by high resolution 1H nuclear magnetic resonance spectroscopy

    High resolution 1H NMR spectroscopy has been employed as a versatile and rapid method to analyze the polar fraction of extra virgin olive oils containing various classes of phenolic compounds. The strategy for identification of phenolic compounds is based on the NMR chemical shifts of a large number of model compounds assigned by using two-dimensional (2D) NMR spectroscopy. Furthermore, 2D NMR was applied to phenolic extracts in an attempt to discover additional phenolic compounds. The 1H NMR methodology was successful in detecting simple phenols, such as p-coumaric acid, vanillic acid, homovanillyl alcohol, vanillin, free tyrosol, and free hydroxytyrosol, the flavonols apigenin and luteolin, the lignans (+) pinoresinol, (+) 1-acetoxypinoresinol and syringaresinol, two isomers of the aldehydic form of oleuropein and ligstroside, the dialdehydic form of oleuropein and ligstroside lacking a carboxymethyl group, and finally total hydroxytyrosol and total tyrosol reflecting the total amounts of free and esterified hydroxytyrol and tyrosol, respectively. The absolute amount of each phenolic constituent was determined in the polar fraction by using anhydrous 1,3,5-triazine as an internal standard

  3. Detection and quantification of phenolic compounds in olive oil by high resolution {sup 1}H nuclear magnetic resonance spectroscopy

    Christophoridou, Stella [NMR Laboratory, Department of Chemistry, University of Crete, P.O. Box 2208, Voutes, 71003 Heraklion, Crete (Greece); Dais, Photis [NMR Laboratory, Department of Chemistry, University of Crete, P.O. Box 2208, Voutes, 71003 Heraklion, Crete (Greece)], E-mail: dais@chemistry.uoc.gr

    2009-02-09

    High resolution {sup 1}H NMR spectroscopy has been employed as a versatile and rapid method to analyze the polar fraction of extra virgin olive oils containing various classes of phenolic compounds. The strategy for identification of phenolic compounds is based on the NMR chemical shifts of a large number of model compounds assigned by using two-dimensional (2D) NMR spectroscopy. Furthermore, 2D NMR was applied to phenolic extracts in an attempt to discover additional phenolic compounds. The {sup 1}H NMR methodology was successful in detecting simple phenols, such as p-coumaric acid, vanillic acid, homovanillyl alcohol, vanillin, free tyrosol, and free hydroxytyrosol, the flavonols apigenin and luteolin, the lignans (+) pinoresinol, (+) 1-acetoxypinoresinol and syringaresinol, two isomers of the aldehydic form of oleuropein and ligstroside, the dialdehydic form of oleuropein and ligstroside lacking a carboxymethyl group, and finally total hydroxytyrosol and total tyrosol reflecting the total amounts of free and esterified hydroxytyrol and tyrosol, respectively. The absolute amount of each phenolic constituent was determined in the polar fraction by using anhydrous 1,3,5-triazine as an internal standard.

  4. Differential Osmotic Behavior of Water Components in Living Skeletal Muscle Resolved by 1H-NMR

    Kimura, Masako; Takemori, Shigeru; YAMAGUCHI, Maki; Umazume, Yoshiki

    2005-01-01

    Using frog sartorius muscle, we observed transverse relaxation processes of 1H-NMR signals from myowater. The process could be well described by four characteristic exponentials: the extremely slow exponential of relaxation time constant T2 > 0.4 s, the slow one of T2 ∼ 0.15 s, the intermediate one of 0.03 s < T2 < 0.06 s, and the rapid one of T2 < 0.03 s. Addition of isotonic extracellular solution affected only the extremely slow exponential, linearly increasing its amplitude and gradually ...

  5. Determination of the Hydrogenation Degree of Telechelic Polybutadiene by {sup 1}H NMR

    Lira, C.H.; Nicolini, L.F.; Dolinsky, M.C.B. [Petroflex Industria e Comercio S.A., Duque de Caxias, RJ (Brazil)]. E-mail: clira@petroflex.com.br; Oliveira, C.M.F.; Gomes, A.S. [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Inst. de Macromoleculas Professora Eloisa Mano

    2006-07-01

    The liquid hydroxyl terminated polybutadiene (HTPB) was hydrogenated to improve its thermal and oxidative resistance. Hydrogenation was carried out using cyclohexane as solvent and a soluble catalyst system consisting of diisobutyl aluminum hydride (DIBAL-H) and Co{sup III} acetylacetonate, at a molar ratio of 6:1. Hydrogenation was only possible after esterification of hydroxyl groups due to interactions with the catalyst system. {sup 1}H NMR technique was used to confirm the esterification and hydrogenation of the polymeric material. This method can be also used to determine the degree of hydrogenation in different reaction times. (author)

  6. 1H MAS NMR spectra of hy- droxyl species on diatomite surface

    2001-01-01

    High spinning speed 1H magic-angle spinning nuclear magnetic resonance (1H MAS NMR) was used to detect surface hydroxyl groups of diatomite, which include isolated hydroxyl groups and hydrogen-bonded hydroxyl groups, and water adsorbed on diatomite surface that include pore water and hydrogen-bonded water. The corresponding proton chemical shifts of above species are ca. 2.0, 6.0-7.1, 4.9 and 3.0 respectively. Accompanied by thermal treatment temperature ascending, the pore water and hydrogen-bonded water are desorbed successively. As a result, the relative intensities of the peaks assigned to protons of isolat-ed hydroxyl groups and hydrogen-bonded hydroxyl groups increase gradually and reach their maxima at 1000℃. After 1100℃ calcination, the hydroxyl groups that classified to strongly hydrogen-bonded ones and the isolated hydroxyl groups condense basically. But some weakly hydrogen-bonded hydroxyl groups may still persist in the micropores.

  7. Direct detection of solanesol in tobacco by 1H and 13C magic angle spinning NMR

    1H and 13C NMR have been used to detect solanesol directly in tobacco without destroying or modifying the sample. Magic angle sample spinning was employed to remove the resonance line broadening due to variations of magnetic susceptibility within the sample. 13C line widths of ca . 10 Hz were obtained. The 1H MAS spectrum of tobacco allows the solanesol signals to be resolved from the broad signal of exchangeable protons. 13C spin-lattice relaxation times (T3) and nuclear Overhauser enhancements (NOE) of solanesol in chloroform solution, in intact tobacco, and as nest oil indicate that the polyisoprene chain motion in tobacco is restricted relative to the motion in solution but still sufficient to average out the dipolar couplings between protons and carbons. (author)

  8. Polymer Molecular Weight Analysis by [Superscript 1]H NMR Spectroscopy

    Izunobi, Josephat U.; Higginbotham, Clement L.

    2011-01-01

    The measurement and analysis of molecular weight and molecular weight distribution remain matters of fundamental importance for the characterization and physical properties of polymers. Gel permeation chromatography (GPC) is the most routinely used method for the molecular weight determination of polymers whereas matrix-assisted laser…

  9. Ligand-receptor Interactions by NMR Spectroscopy

    Novak. P.

    2008-04-01

    Full Text Available Today NMR spectroscopy is a method of choice for elucidation of interactions between biomolecules and the potential ligands. Knowledge on these interactions is an essential prerequisite for the rational drug design. The most important contribution of NMR to drug design a few years ago was the 3D structure determination of proteins. Besides delivering the 3D structures of the free proteins as a raw material for the modeling studies on ligand binding, NMR can directly yield valuable experimental data on the biologically important protein-ligand complexes. In addition to X-ray diffraction, NMR spectroscopy can provide information on the internal protein dynamics ordynamics of intermolecular interactions. Changes in NMR parameters allow us to detect ("SAR by NMR" and quantitatively determine binding affinities (titration, diffusion NMR experiments, etc. of potential ligands. Also, it is possible to determine the binding site and conformations of ligands, receptors and receptor-ligand complexes with the help of NMR methods such as tr-NOESY. Epitopes or functional groups responsible for binding of ligands to the receptor can be identified by employing STD or WaterLOGSY experiments. In this review are described some of the most frequent NMR methods for the characterization of the interactions between biomolecules and ligands, together with their advantages and disadvantages.

  10. Synthesis of Tigogenyl 2-Deoxy-2-phthalimido-D-glucopyranoside Derivatives and Study of their 1H-NMR Spectrum

    Shu Jie HOU; Chuan Chun ZOU; Ping Sheng LEI; De Quan YU

    2004-01-01

    Two protected tigogenyl glycosides were synthesized via parallel synthesis of oligosaccharide. Using chemical synthesis and conformational analysis the reason of the proton signal of 2" acetyl group shifted up field in 1H-NMR was discussed.

  11. Analysis of intracranial cystic disease on 1H MR spectroscopy

    Objective: To analyze the features of intracrayze the features of intracranial cystic diseases on 1H MRS, and to evaluate the applicable value of 1H MRS. Methods: Fifty-two patients were examinated by single voxel 1H MRS, included I-II graded astrocytomas (n=8), glioblastomas (n=9), metastasis (n=13), brain abscesses (n=10), epidermoids (n=4), anachnoid cysts (n=5), brain Cysticerciasis (n=3). Results: (1) There was only Lac in I-II graded astrocytomas. But in glioblastomas, as were as all showed Lac, 4 cases showed low Cho and NAA and 2 cases Lip. (2) In 13 metastasis patients, 7 cases only presented Lac, 6 cases showed Cho, 3 cases showed low NAA and 6 ones Lip. (3) In brain abscesses, all showed Lac, 9 cases displayed AA, 6 cases showed Ace, 5 cases appeared Suc and Ala, 2 eases had Lip. (4) Four eases of epidermoid showed Lac, one showed Lip. In 4 arachnoid cysts, 2 cases had low Lac, one showed Lip. Three cases of cysticercosis showed Lac, Ace, Suc, Ala and no AA, Cho, NAA. Conclusion: Lac is the most common resonance peak on 1H MRS in intracranial cystic diseases and for no diagnostic specificity. AA combined Ace, Suc, and Ala are highly specificity for brain abscess. Ace, Suc and Ala appearance cues the the possible existence of cysticercosis. 1H MRS is helpful for the qualitative diagnosis of intracranial disease. (authors)

  12. 1H NMR metabolomics of earthworm responses to polychlorinated biphenyl (PCB) exposure in soil.

    Whitfield Åslund, Melissa L; Simpson, André J; Simpson, Myrna J

    2011-06-01

    (1)H NMR-based metabolomics was used to examine the metabolic profile of D(2)O-buffer extracted tissues of Eisenia fetida earthworms exposed for 2 days to an artificial soil spiked with sub-lethal concentrations of polychlorinated biphenyls (PCBs) (0, 0.5, 1, 5, 10, or 25 mg/kg Aroclor 1254). Univariate statistical analysis of the identified metabolites revealed a significant increase in ATP concentration in earthworms exposed to the highest soil PCB concentration, but detected no significant changes in other metabolites. However, a multivariate approach which considers alterations in multiple metabolites simultaneously, identified a significant linear relationship between earthworm metabolic profiles and PCB concentration (cross-validated PLS-regression with 7 components, R(2)X = 0.99, R(2)Y = 0.77, Q(2)Y = 0.45, P earthworms (r = 0.22, P = 0.54), but were positively correlated in earthworms from the 25 mg/kg treatment (r = 0.87, P = 0.001). Overall, the observed metabolic responses suggest that PCBs disrupted both carbohydrate (energy) metabolism and membrane (osmolytic) function in E. fetida. The ability of (1)H NMR-based metabolomics to detect these responses suggests that this method offers significant potential for direct assessment of sub-lethal PCB toxicity in soil. PMID:21424327

  13. Study of the formation of carbonyl compounds in edible oils and fats by 1H-NMR and FTIR

    Moya Moreno, M. C. M.; Mendoza Olivares, D.; Amézquita López, F. J.; Peris Martínez, V.; Bosch Reig, F.

    1999-05-01

    Oils and fats start decomposing from the moment they are isolated from their natural environment. Heating accelerates oxidative rancidity and frying at high temperatures produces thermal degradation with the formation of decomposition products, such as aldehydes, ketones, free acids and hydroxilic compounds that in high levels can be harmful to human health. The decomposition products formed up to 300°C were determined by means of 1H-NMR spectroscopy and an FTIR spectroscopic method was developed for the quantification of carbonyl compounds generated during heating. The results show that there is a formation of carbonyl compounds starting at 150°C and when the sample was heated at 300°C for 40 min, the following contents (expressed as butyraldehyde mass fraction) were found: olive oil 10.5%, sunflower oil 11.3%, corn oil 3.0%, seeds oil (sunflower, safflower and canola seed) 6.6% and lard 3.5%.

  14. (1)H NMR-Based Metabolomics Reveals a Pedoclimatic Metabolic Imprinting in Ready-to-Drink Carrot Juices.

    Tomassini, Alberta; Sciubba, Fabio; Di Cocco, Maria Enrica; Capuani, Giorgio; Delfini, Maurizio; Aureli, Walter; Miccheli, Alfredo

    2016-06-29

    Carrots are usually consumed in their native form or processed into many different products. Carrot juice is a popular beverage consumed throughout the world and is attracting increasing attention due to its nutritional value, being a natural source of bioactive compounds. Ready-to-drink carrot juices produced in the same factory were analyzed by (1)H nuclear magnetic resonance (NMR) spectroscopy. The juices were made from carrot roots of the same cultivar grown in three different geographical areas in Italy. More than 30 compounds have been identified and quantified, and the data was subjected to univariate ANOVA and multivariate analyses. Clear geographical-dependent clustering was observed, and the metabolic profiles were related to the different pedoclimatic conditions. The proposed phytoprofiling approach could be employed on an industrial scale to evaluate finished products involving different sites of supply of the raw material, thus improving both the quality and uniformity of the juices. PMID:27281439

  15. Real structure of formamide entrapped by AOT nonaqueous reverse micelles: FT-IR and 1H NMR studies.

    Correa, N Mariano; Pires, Paulo Augusto R; Silber, Juana J; El Seoud, Omar A

    2005-11-10

    Noninvasive techniques such as FT-IR and (1)H NMR spectroscopy have been employed to investigate the solubilization of formamide, FA, and its aqueous solution, FA-water, by sodium 1,4-bis(2-ethylhexyl)sulfosuccinate, AOT, in heptane or isooctane reverse micelles, respectively. Partially deuterated FA (FADH) was used in the FT-IR experiments and nu(OD), n(ND) were analyzed. Also, the nu(C=O) band of FA was investigated. For AOT, the changes of the SO(3)(-) group's symmetric, nu(s), and asymmetric, nu(a), bands were also studied. The results are showing that FA is interacting strongly with the Na+ counterions of the surfactant through electrostatic interactions maintaining their hydrogen bond network present in the FA bulk. Accordingly, partially deuterated FA is "frozen" inside the aggregates and it is possible to detect, by FT-IR technique, the cis and trans isomers. Curve fitting of the nu(OD) (in the FA-water mixture) band requires use of two peaks because the band is asymmetric, not because the solubilizate molecules are present in layers of different structure. The chemical shifts of the (1)H bound to N and C of FA were studied by (1)H NMR. The comparison of the chemical shift of AOT in reverse micelles with FA and the FA-water mixture in the polar core of the aggregate shows that there is a strong preferential solvation of Na+ by FA (through electrostatic interaction) and the AOT's sulfonate group by water (through hydrogen bond interaction). PMID:16853748

  16. The Three-Dimensional Structure of Bovine Calcium Ion-Bound Osteocalcin Using 1H NMR Spectroscopy†

    Dowd, T.L; Rosen, J. F.; Li, L.; Gundberg, C.M.

    2003-01-01

    Structural information on osteocalcin or other noncollagenous bone proteins is very limited. We have solved the three-dimensional structure of calcium bound osteocalcin using 1H 2D NMR techniques and proposed a mechanism for mineral binding. The protons in the 49 amino acid sequence were assigned using standard two-dimensional homonuclear NMR experiments. Distance constraints, dihedral angle constraints, hydrogen bonds, and 1H and 13C chemical shifts were all used to calculate a family of 13 ...

  17. High-resolution NMR spectroscopy under the fume hood.

    Küster, Simon K; Danieli, Ernesto; Blümich, Bernhard; Casanova, Federico

    2011-08-01

    This work reports the possibility to acquire high-resolution (1)H NMR spectra with a fist-sized NMR magnet directly installed under the fume hood. The small NMR sensor based on permanent magnets was used to monitor the trimerization of propionaldehyde catalyzed by indium trichloride in real time by continuously circulating the reaction mixture through the magnet bore in a closed loop with the help of a peristaltic pump. Thanks to the chemical selectivity of NMR spectroscopy the progress of the reaction can be monitored on-line by determining the concentrations of both reactant and product from the area under their respective lines in the NMR spectra as a function of time. This in situ measurement demonstrates that NMR probes can be used in chemistry laboratories, e.g. for reaction optimization, or installed at specific points of interest along industrial process lines. Therefore, it will open the door for the implementation of feedback control based on spectroscopic NMR data. PMID:21698335

  18. L-glutamine: Dynamical properties investigation by means of INS, IR, RAMAN, {sup 1}H NMR and DFT techniques

    Pawlukojć, A., E-mail: andrzej@jinr.ru [Institute of Nuclear Chemistry and Technology, Dorodna 16 str., 03-195 Warsaw (Poland); Joint Institute for Nuclear Research, 141980 Dubna (Russian Federation); Hołderna-Natkaniec, K. [Faculty of Physics, A. Mickiewicz University, 61-614 Poznań (Poland); Bator, G. [Faculty of Chemistry, University of Wroclaw, F. Joliot-Curie 14, 50-383 Wroclaw (Poland); Natkaniec, I. [Joint Institute for Nuclear Research, 141980 Dubna (Russian Federation); Faculty of Physics, A. Mickiewicz University, 61-614 Poznań (Poland)

    2014-10-31

    Graphical abstract: - Highlights: • The L-glutamine was investigated by INS, IR, Raman and {sup 1}H NMR spectroscopy. • DFT calculations for the solids state model were performed. • The NH{sub 3}{sup +} torsional vibration mode is observed in the INS spectra. • Activation energy for the NH{sub 3}{sup +} group reorientation is obtained. - Abstract: Vibrational spectra of L-glutamine in the solid state were studied using the inelastic neutron scattering (INS), infrared (IR), Raman and {sup 1}H NMR spectroscopy techniques. DFT calculation using CASTEP code with the periodic boundary conditions was used to determine and describe the normal modes in the vibrational spectra of pure L-glutamine. An excellent agreement between the calculated and experimental INS, IR and Raman data has been found. Bands assigned to the stretching vibrations of the NH{sub 3}{sup +} group in hydrogen bonds are observed at 2400, 2618 and 2619 cm{sup −1}, while the NH{sub 3}{sup +} torsion vibration mode is observed at 441 cm{sup −1}. The band at 2041 cm{sup −1} is assigned to combinations of the NH{sub 3}{sup +} bending symmetry vibration and the CO{sub 2}{sup -} rocking vibration and can be used as an “indicator band” for the identification of the NH{sub 3}{sup +} groups in amino acid. For the L-glutamine an activation energy needed for the NH{sub 3}{sup +} group reorientation was obtained as 7.4 kcal/mol. It was found, that the combination three spectroscopic methods (INS, IR and Raman) with calculations for the crystal state proved to be an effective tool to investigate dynamical properties of amino acid crystals.

  19. L-glutamine: Dynamical properties investigation by means of INS, IR, RAMAN, 1H NMR and DFT techniques

    Graphical abstract: - Highlights: • The L-glutamine was investigated by INS, IR, Raman and 1H NMR spectroscopy. • DFT calculations for the solids state model were performed. • The NH3+ torsional vibration mode is observed in the INS spectra. • Activation energy for the NH3+ group reorientation is obtained. - Abstract: Vibrational spectra of L-glutamine in the solid state were studied using the inelastic neutron scattering (INS), infrared (IR), Raman and 1H NMR spectroscopy techniques. DFT calculation using CASTEP code with the periodic boundary conditions was used to determine and describe the normal modes in the vibrational spectra of pure L-glutamine. An excellent agreement between the calculated and experimental INS, IR and Raman data has been found. Bands assigned to the stretching vibrations of the NH3+ group in hydrogen bonds are observed at 2400, 2618 and 2619 cm−1, while the NH3+ torsion vibration mode is observed at 441 cm−1. The band at 2041 cm−1 is assigned to combinations of the NH3+ bending symmetry vibration and the CO2- rocking vibration and can be used as an “indicator band” for the identification of the NH3+ groups in amino acid. For the L-glutamine an activation energy needed for the NH3+ group reorientation was obtained as 7.4 kcal/mol. It was found, that the combination three spectroscopic methods (INS, IR and Raman) with calculations for the crystal state proved to be an effective tool to investigate dynamical properties of amino acid crystals

  20. Thermal degradation in a trimodal PDMS network by 1H Multiple Quantum NMR

    Giuliani, J R; Gjersing, E L; Chinn, S C; Jones, T V; Wilson, T S; Alviso, C T; Herberg, J L; Pearson, M A; Maxwell, R S

    2007-06-06

    Thermal degradation of a filled, crosslinked siloxane material synthesized from PDMS chains of three different average molecular weights and with two different crosslinking species has been studied by {sup 1}H Multiple Quantum (MQ) NMR methods. Multiple domains of polymer chains were detected by MQ NMR exhibiting Residual Dipolar Coupling (<{Omega}{sub d}>) values of 200 Hz and 600 Hz, corresponding to chains with high average molecular weight between crosslinks and chains with low average molecular weight between crosslinks or near the multifunctional crosslinking sites. Characterization of the <{Omega}{sub d}> values and changes in <{Omega}{sub d}> distributions present in the material were studied as a function of time at 250 C and indicates significant time dependent degradation. For the domains with low <{Omega}{sub d}>, a broadening in the distribution was observed with aging time. For the domain with high <{Omega}{sub d}>, increases in both the mean <{Omega}{sub d}> and the width in <{Omega}{sub d}> were observed with increasing aging time. Isothermal Thermal Gravimetric Analysis (TGA) reveals a 3% decrease in weight over 20 hours of aging at 250 C. Degraded samples also were analyzed by traditional solid state {sup 1}H NMR techniques and offgassing products were identified by Solid Phase MicroExtraction followed by Gas Chromatography-Mass Spectrometry (SPME GC-MS). The results, which will be discussed here, suggest that thermal degradation proceeds by complex competition between oxidative chain scissioning and post-curing crosslinking that both contribute to embrittlement.

  1. Mobile sensor for high resolution NMR spectroscopy and imaging

    Danieli, Ernesto; Mauler, Jörg; Perlo, Juan; Blümich, Bernhard; Casanova, Federico

    2009-05-01

    In this work we describe the construction of a mobile NMR tomograph with a highly homogeneous magnetic field. Fast MRI techniques as well as NMR spectroscopy measurements were carried out. The magnet is based on a Halbach array built from identical permanent magnet blocks generating a magnetic field of 0.22 T. To shim the field inhomogeneities inherent to magnet arrays constructed from these materials, a shim strategy based on the use of movable magnet blocks is employed. With this approach a reduction of the line-width from ˜20 kHz to less than 0.1 kHz was achieved, that is by more than two orders of magnitude, in a volume of 21 cm 3. Implementing a RARE sequence, 3D images of different objects placed in this volume were obtained in short experimental times. Moreover, by reducing the sample size to 1 cm 3, sub ppm resolution is obtained in 1H NMR spectra.

  2. 1H and 7Li NMR in li2-xhxmo3 (m = Ti, Zr)

    Baklanova, Ya

    2008-01-01

    Nuclear magnetic resonance (NMR), Raman spectroscopy and thermogravimetric methods were used to study the peculiarities of lithium ion replacement by protons in lithium metallates Li2MO3 (M=Ti, Zr). In this article we show that almost all protons in the final substitution products H2MO3 enter into the crystal structure. All protons in zirconium hydroxide belong to hydrogen-bonded OH-groups. Contrary, titanium hydroxide contains both hydrogen-bonded and isolated OH-groups. Protons in H2ZrO3 fo...

  3. Automatic Structure Determination of Regular Polysaccharides Based Solely on NMR Spectroscopy

    Lundborg, Magnus; Fontana, Carolina; Widmalm, Göran

    2011-01-01

    The structural analysis of polysaccharides requires that the sugar components and their absolute configurations are determined. We here show that this can be performed based on NMR spectroscopy by utilizing butanolysis with (+)- and (−)-2-butanol that gives the corresponding 2-butyl glycosides with characteristic 1H and 13C NMR chemical shifts. The subsequent computer-assisted structural determination by CASPER can then be based solely on NMR data in a fully automatic way as shown and impleme...

  4. 1H NMR Relaxation Investigation of Inhibitors Interacting with Torpedo californica Acetylcholinesterase

    Delfini, Maurizio; Gianferri, Raffaella; Dubbini, Veronica; Manetti, Cesare; Gaggelli, Elena; Valensin, Gianni

    2000-05-01

    Two naphthyridines interacting with Torpedo californica acetylcholinesterase (AChE) were investigated. 1H NMR spectra were recorded and nonselective, selective, and double-selective spin-lattice relaxation rates were measured. The enhancement of selective relaxation rates could be titrated by different ligand concentrations at constant AChE (yielding 0.22 and 1.53 mM for the dissociation constants) and was providing evidence of a diverse mode of interaction. The double-selective relaxation rates were used to evaluate the motional correlation times of bound ligands at 34.9 and 36.5 ns at 300 K. Selective relaxation rates of bound inhibitors could be interpreted also in terms of dipole-dipole interactions with protons in the enzyme active site.

  5. 1H NMR Cryoporometry Study of the Melting Behavior of Water in White Cement

    Boguszyńska, Joanna; Tritt-Goc, Jadwiga

    2004-09-01

    The pore size of white cement samples is studied by the melting behaviour of water confined in it, using 1H NMR cryopormetry. The influence of the preparing method and antifreeze admixture on the pore size and distribution in cement samples is investigated at 283 K. The addition of an antifreeze admixture [containing 1% Sika Rapid 2 by weight of the dry cement] influences the porosity. In wet prepared samples we observed a significant increase in the quantity of mesopores between 0.8 and 5 nm and a smaller increase of mesopores between 5 and 10 nm, when compared to cement without admixture. The compressive strength is related to the porosity of the cement. Therefore the cement with Sika Rapid 2, wet prepared at 278 K shows a higher strength than all other measured samples.

  6. Multivariate modelling with 1H NMR of pleural effusion in murine cerebral malaria

    Ghosh Soumita

    2011-11-01

    Full Text Available Abstract Background Cerebral malaria is a clinical manifestation of Plasmodium falciparum infection. Although brain damage is the predominant pathophysiological complication of cerebral malaria (CM, respiratory distress, acute lung injury, hydrothorax/pleural effusion are also observed in several cases. Immunological parameters have been assessed in pleural fluid in murine models; however there are no reports of characterization of metabolites present in pleural effusion. Methods 1H NMR of the sera and the pleural effusion of cerebral malaria infected mice were analyzed using principal component analysis, orthogonal partial least square analysis, multiway principal component analysis, and multivariate curve resolution. Results It has been observed that there was 100% occurrence of pleural effusion (PE in the mice affected with CM, as opposed to those are non-cerebral and succumbing to hyperparasitaemia (NCM/HP. An analysis of 1H NMR and SDS-PAGE profile of PE and serum samples of each of the CM mice exhibited a similar profile in terms of constituents. Multivariate analysis on these two classes of biofluids was performed and significant differences were detected in concentrations of metabolites. Glucose, creatine and glutamine contents were high in the PE and lipids being high in the sera. Multivariate curve resolution between sera and pleural effusion showed that changes in PE co-varied with that of serum in CM mice. The increase of glucose in PE is negatively correlated to the glucose in serum in CM as obtained from the result of multiway principal component analysis. Conclusions This study reports for the first time, the characterization of metabolites in pleural effusion formed during murine cerebral malaria. The study indicates that the origin of PE metabolites in murine CM may be the serum. The loss of the components like glucose, glutamine and creatine into the PE may worsen the situation of patients, in conjunction with the enhanced

  7. 1H NMR studies of selective interactions of norfloxacin with double-stranded DNA

    The interaction of the antibiotic drug norfloxacin with double-stranded DNA containing interior 5'-CpG-3', 5'-GpC-3', and 5'-GpG-3' steps was studied by 1H NMR. The drug is in fast exchange on the NMR timescale. A highly selective broadening of the imino proton resonances assigned to central CpG steps was observed after addition of drug, indicating an intercalation-like interaction. DNA sequences with central CpG steps also displayed broadening of non-hydrogen-bonded cytosine amino protons in the major groove upon addition of norfloxacin. Furthermore, a sequence-independent selective broadening of the adenine H2 resonance and an upfield shift of the guanine amino proton resonance, both protons located in the minor groove, was observed. Two-dimensional-NOESY spectra showed that no significant structural changes were induced in the DNA by the drug. The results suggest that the planar two-ring system of norfloxacin partially intercalates into CpG steps and that the drug also exhibits non-specific groove binding

  8. Tetrapropylammonium Occlusion in Nanoaggregates of Precursor of Silicalite-1 Zeolite Studied by 1H and 13C NMR

    Mohamed Haouas

    2016-06-01

    Full Text Available The dynamic behavior of tetrapropylammonium (TPA cations in the clear precursor sols for silicalite synthesis has been investigated by 1H diffusion ordered spectroscopy (DOSY, T1, T2, and T1ρ 1H relaxation, as well as 1H→13C cross polarization (CP nuclear magnetic resonance. The DOSY NMR experiments showed the presence of strong solute–solvent interactions in concentrated sols, which are decreasing upon dilution. Similarities in dependence of diffusion coefficients with fractional power of the viscosity constant observed for nanoparticles, TPA cations and water led to the conclusion that they aggregate as anisotropic silicate-TPA particles. Relaxation studies as well as 1H→13C CP experiments provide information on dynamic properties of ethanol, water and TPA cations, which are function of silicate aggregates. The general tendency showed that the presence of silicate as oligomers and particles decreases the relaxation times, in particular T2 and T1ρH, as a consequence of involvement of these latter in ion-pairing interactions with water-solvated TPA molecules slowing down their mobility. Furthermore, from the 1H→13C CP dynamics curve profiles a change in the CP transfer regime was observed from fast (TCH << T1ρH for solutions without silicates to moderate (TCH~T1ρH when silicates are interacting with the TPA cations that may reflect the occlusion of TPA into flexible silicate hydrate aggregates.

  9. Towards high resolution ^1H NMR spectra of tannin colloidal aggregates

    Mirabel, M.; Glories, Y.; Pianet, I.; Dufourc, E. J.

    1999-10-01

    The time dependent colloidal formation of tannins in hydro-alcoholic medium has been studied by 1H-NMR. Line broadening observed with time can be cancelled by making use of magic angle sample spinning (MASS) thus yielding sharp lines that allow structural studies. We used as an example catechin, a constitutive monomer of Bordeaux young red wine tannins. Chemical shift variations of polyphenol protons allow monitoring the time course of aggregation. La formation de tanins colloïdaux au cours du temps, en milieu hydroalcoolique, a été suivie par RMN-^1H. Un élargissement marqué des résonances est observé et peut être supprimé par la rotation de l'échantillon à l'angle magique ce qui ouvre tout un champ d'études structurales sur ces composés colloïdaux. L'exemple proposé est celui de la catéchine, monomère constitutif de tannins présents en grande quantité dans les vins rouges jeunes de Bordeaux. Des variations du déplacement chimique de certains protons polyphénoliques permettent de suivre l'évolution temporelle de l'agrégation.

  10. 1H NMR-based metabolite profiling of diet-induced obesity in a mouse mode

    Jee-youn Jung1,2,#, Il Yong Kim3,#, Yo Na Kim3,#, Jin-sup Kim1,5, Jae Hoon Shin3, Zi-hey Jang1,5, Ho-Sub Lee2, Geum-Sook Hwang1,5,* & Je Kyung Seong3,4,*

    2012-07-01

    Full Text Available High-fat diets (HFD and high-carbohydrate diets (HCD-induced obesity through different pathways, but the metabolicdifferences between these diets are not fully understood.Therefore, we applied proton nuclear magnetic resonance (1HNMR-based metabolomics to compare the metabolic patternsbetween C57BL/6 mice fed HCD and those fed HFD. Principalcomponent analysis derived from 1H NMR spectra of urineshowed a clear separation between the HCD and HFD groups.Based on the changes in urinary metabolites, the slow rate ofweight gain in mice fed the HCD related to activation of thetricarboxylic acid cycle (resulting in increased levels of citrateand succinate in HCD mice, while the HFD affected nicotinamidemetabolism (increased levels of 1-methylnicotineamide,nicotinamide-N-oxide in HFD mice, which leads to systemicoxidative stress. In addition, perturbation of gut microflorametabolism was also related to different metabolic patterns ofthose two diets. These findings demonstrate that 1H NMRbasedmetabolomics can identify diet-dependent perturbationsin biological pathways.