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Sample records for nmr analysis results

  1. Facilitating the performance of qNMR analysis using automated quantification and results verification.

    Science.gov (United States)

    Monakhova, Yulia B; Diehl, Bernd W K

    2017-09-01

    Quantitative nuclear magnetic resonance (qNMR) is considered as a powerful tool for measuring the absolute amount of small molecules in complex mixtures. However, verification of the accuracy of such quantification is not a trivial task. In particular, preprocessing and integration steps are challenging and potentially erroneous. A script was developed in Matlab environment to automate qNMR analysis. Verification of the results is based on two evolving integration profiles. The analysis of binary mixtures of internal standards as well as pharmaceutical products has shown that all common artifacts (phase and baseline distortion, impurities) can be easily recognized in routine qNMR experiments. In the absence of distortion, deviation between automatically (mean value of several integrals) and manually calculated values was generally below 0.1%. The routine is independent of multiplet pattern, solvent, spectrometer, nuclei type and pulse sequence used. In general, the usage of the developed script can facilitate and verify results of routine qNMR analysis in an automatic manner. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

  2. PVT Degradation Studies: NMR Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Herman M. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Kouzes, Richard T. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2017-06-06

    Under certain environmental conditions, polyvinyl toluene (PVT) plastic scintillator has been observed to undergo internal fogging. Nuclear magnetic resonance spectroscopy has been used to elucidate the state of water inside the PVT. The deuterium NMR results show that water absorbed by PVT under warm, humid conditions enters several distinct environments, and when the PVT is transferred from incubation to ambient temperature and humidity the water is lost on a time scale of a few hours from these samples. Most of the deuterium NMR peaks can be assigned to bulk liquid water, but almost 35% of the detected signal intensity is contained in a resonance that resembles spectra of water contained in nanometer-scale pores in mesoporous carbon.

  3. [Rapid analysis of suppositories by quantitative 1H NMR spectroscopy].

    Science.gov (United States)

    Abramovich, R A; Kovaleva, S A; Goriainov, S V; Vorob'ev, A N; Kalabin, G A

    2012-01-01

    Rapid analysis of suppositories with ibuprofen and arbidol by quantitative 1H NMR spectroscopy was performed. Optimal conditions for the analysis were developed. The results are useful for design of rapid methods for quality control of suppositories with different components

  4. Multispectral dual isotope and NMR image analysis

    Energy Technology Data Exchange (ETDEWEB)

    Vannier, M.W.; Beihn, R.M.; Butterfield, R.L.; De Land, F.H.

    1985-05-01

    Dual isotope scintigraphy and nuclear magnetic resonance imaging produce image data that is intrinsically multispectral. That is multiple images of the same anatomic region are generated with different gray scale distribution and morphologic content that is largely redundant. Image processing technology, originally developed by NASA for satellite imaging, is available for multispectral analysis. These methods have been applied to provide tissue characterization. Tissue specific information encoded in the grapy scale data from dual isotope and NMR studies may be extracted using multispectral pattern recognition methods. The authors used table lookup minimum distance, maximum likelihood and cluster analysis techniques with data sets from Ga-67 / Tc-99m, 1-131 labeled antibodies / Tc-99m, Tc-99m perfusion / Xe-133 ventilation, and NMR studies. The results show; tissue characteristic signatures exist in dual isotope and NMR imaging, and these spectral signatures are identifiable using multispectral image analysis and provide tissue classification maps with scatter diagrams that facilitate interpretation and assist in elucidating subtle changes.

  5. NMR spectroscopy: a tool for conformational analysis

    Energy Technology Data Exchange (ETDEWEB)

    Tormena, Claudio F.; Cormanich, Rodrigo A.; Rittner, Roberto, E-mail: rittner@iqm.unicamp.br [Universidade Estadual de Campinas (UNICAMP), SP (Brazil). Inst. de Quimica. Lab. de Fisico-Quimica Organica; Freitas, Matheus P. [Universidade Federal de Lavras (UFLA), MG (Brazil). Dept. de Qumica

    2011-07-01

    The present review deals with the application of NMR data to the conformational analysis of simple organic compounds, together with other experimental methods like infrared spectroscopy and with theoretical calculations. Each sub-section describes the results for a group of compounds which belong to a given organic function like ketones, esters, etc. Studies of a single compound, even of special relevance, were excluded since the main goal of this review is to compare the results for a given function, where different substituents were used or small structural changes were introduced in the substrate, in an attempt to disclose their effects in the conformational equilibrium. Moreover, the huge amount of data available in the literature, on this research field, imposed some limitations which will be detailed in the Introduction, but it can be reminded in advance that these limitations include mostly the period when these results were published. (author)

  6. NMR spectroscopy: a tool for conformational analysis

    International Nuclear Information System (INIS)

    Tormena, Claudio F.; Cormanich, Rodrigo A.; Rittner, Roberto; Freitas, Matheus P.

    2011-01-01

    The present review deals with the application of NMR data to the conformational analysis of simple organic compounds, together with other experimental methods like infrared spectroscopy and with theoretical calculations. Each sub-section describes the results for a group of compounds which belong to a given organic function like ketones, esters, etc. Studies of a single compound, even of special relevance, were excluded since the main goal of this review is to compare the results for a given function, where different substituents were used or small structural changes were introduced in the substrate, in an attempt to disclose their effects in the conformational equilibrium. Moreover, the huge amount of data available in the literature, on this research field, imposed some limitations which will be detailed in the Introduction, but it can be reminded in advance that these limitations include mostly the period when these results were published. (author)

  7. ImatraNMR: Novel software for batch integration and analysis of quantitative NMR spectra

    Science.gov (United States)

    Mäkelä, A. V.; Heikkilä, O.; Kilpeläinen, I.; Heikkinen, S.

    2011-08-01

    Quantitative NMR spectroscopy is a useful and important tool for analysis of various mixtures. Recently, in addition of traditional quantitative 1D 1H and 13C NMR methods, a variety of pulse sequences aimed for quantitative or semiquantitative analysis have been developed. To obtain actual usable results from quantitative spectra, they must be processed and analyzed with suitable software. Currently, there are many processing packages available from spectrometer manufacturers and third party developers, and most of them are capable of analyzing and integration of quantitative spectra. However, they are mainly aimed for processing single or few spectra, and are slow and difficult to use when large numbers of spectra and signals are being analyzed, even when using pre-saved integration areas or custom scripting features. In this article, we present a novel software, ImatraNMR, designed for batch analysis of quantitative spectra. In addition to capability of analyzing large number of spectra, it provides results in text and CSV formats, allowing further data-analysis using spreadsheet programs or general analysis programs, such as Matlab. The software is written with Java, and thus it should run in any platform capable of providing Java Runtime Environment version 1.6 or newer, however, currently it has only been tested with Windows and Linux (Ubuntu 10.04). The software is free for non-commercial use, and is provided with source code upon request.

  8. CcpNmr AnalysisAssign: a flexible platform for integrated NMR analysis

    Energy Technology Data Exchange (ETDEWEB)

    Skinner, Simon P.; Fogh, Rasmus H. [University of Leicester, Department of Molecular and Cell Biology, Leicester Institute for Structural- and Chemical Biology (United Kingdom); Boucher, Wayne [University of Cambridge, Department of Biochemistry (United Kingdom); Ragan, Timothy J.; Mureddu, Luca G.; Vuister, Geerten W., E-mail: gv29@le.ac.uk [University of Leicester, Department of Molecular and Cell Biology, Leicester Institute for Structural- and Chemical Biology (United Kingdom)

    2016-10-15

    NMR spectroscopy is an indispensably powerful technique for the analysis of biomolecules under ambient conditions, both for structural- and functional studies. However, in practice the complexity of the technique has often frustrated its application by non-specialists. In this paper, we present CcpNmr version-3, the latest software release from the Collaborative Computational Project for NMR, for all aspects of NMR data analysis, including liquid- and solid-state NMR data. This software has been designed to be simple, functional and flexible, and aims to ensure that routine tasks can be performed in a straightforward manner. We have designed the software according to modern software engineering principles and leveraged the capabilities of modern graphics libraries to simplify a variety of data analysis tasks. We describe the process of backbone assignment as an example of the flexibility and simplicity of implementing workflows, as well as the toolkit used to create the necessary graphics for this workflow. The package can be downloaded from www.ccpn.ac.uk/v3-software/downloads http://www.ccpn.ac.uk/v3-software/downloads and is freely available to all non-profit organisations.

  9. NMR

    International Nuclear Information System (INIS)

    Kneeland, J.B.; Lee, B.C.P.; Whalen, J.P.; Knowles, R.J.R.; Cahill, P.T.

    1984-01-01

    Although still quite new, NMR imaging has already emerged as a safe, noninvasive, painless, and effective diagnostic modality requiring no ionizing radiation. Also, NMR appears already to have established itself as the method of choice for the examination of the brain spinal cord (excluding herniated disks). Another area in which NMR excels is in the examination of the pelvis. The use of surface coils offers the promise of visualizing structures with resolution unobtainable by any other means. In addition, NMR, with its superb visualization of vascular structures and potential ability to measure flow, may soon revolutionize the diagnosis of cardiovascular disease. Finally, NMR, through biochemically and physiologically based T/sub 1/ and T/sub 2/ indices or through spectroscopy, may provide a means of monitoring therapeutic response so as to permit tailoring of treatment to the individual patient. In short, NMR is today probably at the same stage as the x-ray was in Roentgen's day

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

    International Nuclear Information System (INIS)

    Monakhova, Yulia B.; Godelmann, Rolf; Hermann, Armin; Kuballa, Thomas; Cannet, Claire; Schäfer, Hartmut; Spraul, Manfred; Rutledge, Douglas N.

    2014-01-01

    Highlights: • 1 H NMR profilings of 718 wines were fused with stable isotope analysis data (SNIF-NMR, 18 O, 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 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 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 1 H NMR profiles are fused with stable isotope (SNIF-NMR, 18 O, 13 C) data. Variable selection based on clustering of latent variables was performed on 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 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 1 H NMR data alone in 82–89% respectively). Certain enhancement was obtained also for the year of vintage (from 88 to 97% for 1 H NMR to 99% for the fused data), whereas in case of grape varieties improved models were not obtained. The combination of 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

  11. A global analysis of NMR distance constraints from the PDB

    International Nuclear Information System (INIS)

    Vranken, Wim

    2007-01-01

    Information obtained from Nuclear Magnetic Resonance (NMR) experiments is encoded as a set of constraint lists when calculating three-dimensional structures for a protein. With the amount of constraint data from the world wide Protein Data Bank (wwPDB) that is now available, it is possible to do a global, large-scale analysis using only information from the constraints, without taking the coordinate information into account. This article describes such an analysis of distance constraints from NOE data based on a set of 1834 NMR PDB entries containing 1909 protein chains. In order to best represent the quality and extent of the data that is currently deposited at the wwPDB, only the original data as deposited by the authors was used, and no attempt was made to 'clean up' and further interpret this information. Because the constraint lists provide a single set of data, and not an ensemble of structural solutions, they are easier to analyse and provide a reduced form of structural information that is relevant for NMR analysis only. The online resource resulting from this analysis makes it possible to check, for example, how often a particular contact occurs when assigning NOESY spectra, or to find out whether a particular sequence fragment is likely to be difficult to assign. In this respect it formalises information that scientists with experience in spectrum analysis are aware of but cannot necessarily quantify. The analysis described here illustrates the importance of depositing constraints (and all other possible NMR derived information) along with the structure coordinates, as this type of information can greatly assist the NMR community

  12. Quantitative produced water analysis using mobile 1H NMR

    Science.gov (United States)

    Wagner, Lisabeth; Kalli, Chris; Fridjonsson, Einar O.; May, Eric F.; Stanwix, Paul L.; Graham, Brendan F.; Carroll, Matthew R. J.; Johns, Michael L.

    2016-10-01

    Measurement of oil contamination of produced water is required in the oil and gas industry to the (ppm) level prior to discharge in order to meet typical environmental legislative requirements. Here we present the use of compact, mobile 1H nuclear magnetic resonance (NMR) spectroscopy, in combination with solid phase extraction (SPE), to meet this metrology need. The NMR hardware employed featured a sufficiently homogeneous magnetic field, such that chemical shift differences could be used to unambiguously differentiate, and hence quantitatively detect, the required oil and solvent NMR signals. A solvent system consisting of 1% v/v chloroform in tetrachloroethylene was deployed, this provided a comparable 1H NMR signal intensity for the oil and the solvent (chloroform) and hence an internal reference 1H signal from the chloroform resulting in the measurement being effectively self-calibrating. The measurement process was applied to water contaminated with hexane or crude oil over the range 1-30 ppm. The results were validated against known solubility limits as well as infrared analysis and gas chromatography.

  13. NMR Analysis of Some Pentacycloundecanedione Derivatives

    African Journals Online (AJOL)

    NJD

    was used to assist with the elucidation of the asymmetric ketal structure. KEYWORDS. NMR elucidation, pentacycloundecane, 2D NMR. 1. Introduction. The chemistry ... intermediate for the diol 413,14 which is used in the synthesis of various crown ethers13,15–17 and macrocycles.11,18. 2. Experimental. The four products ...

  14. Phosphorus-31 NMR analysis of gold plating baths

    Energy Technology Data Exchange (ETDEWEB)

    Smith, R.E.

    1992-03-01

    This report describes the nuclear magnetic resonance (NMR) analysis of gold plating baths in the Micro-Miniature Electronic Assembly department of Allied-Signal Inc., Kansas City Division (KCD). The baths were analyzed for phosphorylated components. In freshly prepared gold plating baths in this department the principle compound observed is aminotrimethyl-phosphonate, or ATMP. As the bath is used in production, the ATMP breaks down; and new compounds, aminodimethylphosphonate (ADMP), aminomonomethylphosphonate, (AMMP), and inorganic phosphate (H{sub 2}PO{sub 4}{sup {minus}}), are formed. The NMR method has been used for almost three years to monitor the concentrations of the ATMP and breakdown products. In a previous report, results from January through October 1988 were reported. In this report, results from November 1988 through January 1991 are given.

  15. Automated NMR relaxation dispersion data analysis using NESSY

    Directory of Open Access Journals (Sweden)

    Gooley Paul R

    2011-10-01

    Full Text Available Abstract Background Proteins are dynamic molecules with motions ranging from picoseconds to longer than seconds. Many protein functions, however, appear to occur on the micro to millisecond timescale and therefore there has been intense research of the importance of these motions in catalysis and molecular interactions. Nuclear Magnetic Resonance (NMR relaxation dispersion experiments are used to measure motion of discrete nuclei within the micro to millisecond timescale. Information about conformational/chemical exchange, populations of exchanging states and chemical shift differences are extracted from these experiments. To ensure these parameters are correctly extracted, accurate and careful analysis of these experiments is necessary. Results The software introduced in this article is designed for the automatic analysis of relaxation dispersion data and the extraction of the parameters mentioned above. It is written in Python for multi platform use and highest performance. Experimental data can be fitted to different models using the Levenberg-Marquardt minimization algorithm and different statistical tests can be used to select the best model. To demonstrate the functionality of this program, synthetic data as well as NMR data were analyzed. Analysis of these data including the generation of plots and color coded structures can be performed with minimal user intervention and using standard procedures that are included in the program. Conclusions NESSY is easy to use open source software to analyze NMR relaxation data. The robustness and standard procedures are demonstrated in this article.

  16. Multivariate analysis relating oil shale geochemical properties to NMR relaxometry

    Science.gov (United States)

    Birdwell, Justin E.; Washburn, Kathryn E.

    2015-01-01

    Low-field nuclear magnetic resonance (NMR) relaxometry has been used to provide insight into shale composition by separating relaxation responses from the various hydrogen-bearing phases present in shales in a noninvasive way. Previous low-field NMR work using solid-echo methods provided qualitative information on organic constituents associated with raw and pyrolyzed oil shale samples, but uncertainty in the interpretation of longitudinal-transverse (T1–T2) relaxometry correlation results indicated further study was required. Qualitative confirmation of peaks attributed to kerogen in oil shale was achieved by comparing T1–T2 correlation measurements made on oil shale samples to measurements made on kerogen isolated from those shales. Quantitative relationships between T1–T2 correlation data and organic geochemical properties of raw and pyrolyzed oil shales were determined using partial least-squares regression (PLSR). Relaxometry results were also compared to infrared spectra, and the results not only provided further confidence in the organic matter peak interpretations but also confirmed attribution of T1–T2 peaks to clay hydroxyls. In addition, PLSR analysis was applied to correlate relaxometry data to trace element concentrations with good success. The results of this work show that NMR relaxometry measurements using the solid-echo approach produce T1–T2 peak distributions that correlate well with geochemical properties of raw and pyrolyzed oil shales.

  17. Crystallographically-based analysis of the NMR spectra of maghemite

    International Nuclear Information System (INIS)

    Spiers, K.M.; Cashion, J.D.

    2012-01-01

    All possible iron environments with respect to nearest neighbour vacancies in vacancy-ordered and vacancy-disordered maghemite have been evaluated and used as the foundation for a crystallographically-based analysis of the published NMR spectra of maghemite. The spectral components have been assigned to particular configurations and excellent agreement obtained in comparing predicted spectra with published spectra taken in applied magnetic fields. The broadness of the published NMR lines has been explained by calculations of the magnetic dipole fields at the various iron sites and consideration of the supertransferred hyperfine fields. - Highlights: ► Analysis of 57 Fe NMR of maghemite based on vacancy ordering and nearest neighbour vacancies. ► Assignment of NMR spectral components based on crystallographic analysis of unique iron sites. ► Strong agreement between predicted spectra and published spectra taken in applied magnetic fields. ► Maghemite NMR spectral broadening due to various iron sites and supertransferred hyperfine field.

  18. NMR analysis of compositional heterogeneity in polysaccharides

    Science.gov (United States)

    Many copolysaccharides are compositionally heterogeneous, and the composition determined by the usual analytical or spectroscopic methods provides only an average value. For some polysaccharides, the NMR data contain copolymer sequence information, such as diad, triad, and tetrad sequence intensiti...

  19. Optimized "detectors" for dynamics analysis in solid-state NMR

    Science.gov (United States)

    Smith, Albert A.; Ernst, Matthias; Meier, Beat H.

    2018-01-01

    Relaxation in nuclear magnetic resonance (NMR) results from stochastic motions that modulate anisotropic NMR interactions. Therefore, measurement of relaxation-rate constants can be used to characterize molecular-dynamic processes. The motion is often characterized by Markov processes using an auto-correlation function, which is assumed to be a sum of multiple decaying exponentials. We have recently shown that such a model can lead to severe misrepresentation of the real motion, when the real correlation function is more complex than the model. Furthermore, multiple distributions of motion may yield the same set of dynamics data. Therefore, we introduce optimized dynamics "detectors" to characterize motions which are linear combinations of relaxation-rate constants. A detector estimates the average or total amplitude of motion for a range of motional correlation times. The information obtained through the detectors is less specific than information obtained using an explicit model, but this is necessary because the information contained in the relaxation data is ambiguous, if one does not know the correct motional model. On the other hand, if one has a molecular dynamics trajectory, one may calculate the corresponding detector responses, allowing direct comparison to experimental NMR dynamics analysis. We describe how to construct a set of optimized detectors for a given set of relaxation measurements. We then investigate the properties of detectors for a number of different data sets, thus gaining an insight into the actual information content of the NMR data. Finally, we show an example analysis of ubiquitin dynamics data using detectors, using the DIFRATE software.

  20. Nanogram-scale preparation and NMR analysis for mass-limited small volatile compounds.

    Directory of Open Access Journals (Sweden)

    Satoshi Nojima

    2011-03-01

    Full Text Available Semiochemicals are often produced in infinitesimally small quantities, so their isolation requires large amounts of starting material, not only requiring significant effort in sample preparation, but also resulting in a complex mixture of compounds from which the bioactive compound needs to be purified and identified. Often, compounds cannot be unambiguously identified by their mass spectra alone, and NMR analysis is required for absolute chemical identification, further exacerbating the situation because NMR is relatively insensitive and requires large amounts of pure analyte, generally more than several micrograms. We developed an integrated approach for purification and NMR analysis of <1 µg of material. Collections from high performance preparative gas-chromatography are directly eluted with minimal NMR solvent into capillary NMR tubes. With this technique, (1H-NMR spectra were obtained on 50 ng of geranyl acetate, which served as a model compound, and reasonable H-H COSY NMR spectra were obtained from 250 ng of geranyl acetate. This simple off-line integration of preparative GC and NMR will facilitate the purification and chemical identification of novel volatile compounds, such as insect pheromones and other semiochemicals, which occur in minute (sub-nanogram, and often limited, quantities.

  1. PDBStat: a universal restraint converter and restraint analysis software package for protein NMR

    International Nuclear Information System (INIS)

    Tejero, Roberto; Snyder, David; Mao, Binchen; Aramini, James M.; Montelione, Gaetano T.

    2013-01-01

    The heterogeneous array of software tools used in the process of protein NMR structure determination presents organizational challenges in the structure determination and validation processes, and creates a learning curve that limits the broader use of protein NMR in biology. These challenges, including accurate use of data in different data formats required by software carrying out similar tasks, continue to confound the efforts of novices and experts alike. These important issues need to be addressed robustly in order to standardize protein NMR structure determination and validation. PDBStat is a C/C++ computer program originally developed as a universal coordinate and protein NMR restraint converter. Its primary function is to provide a user-friendly tool for interconverting between protein coordinate and protein NMR restraint data formats. It also provides an integrated set of computational methods for protein NMR restraint analysis and structure quality assessment, relabeling of prochiral atoms with correct IUPAC names, as well as multiple methods for analysis of the consistency of atomic positions indicated by their convergence across a protein NMR ensemble. In this paper we provide a detailed description of the PDBStat software, and highlight some of its valuable computational capabilities. As an example, we demonstrate the use of the PDBStat restraint converter for restrained CS-Rosetta structure generation calculations, and compare the resulting protein NMR structure models with those generated from the same NMR restraint data using more traditional structure determination methods. These results demonstrate the value of a universal restraint converter in allowing the use of multiple structure generation methods with the same restraint data for consensus analysis of protein NMR structures and the underlying restraint data

  2. NMR data visualization, processing, and analysis on mobile devices.

    Science.gov (United States)

    Cobas, Carlos; Iglesias, Isaac; Seoane, Felipe

    2015-08-01

    Touch-screen computers are emerging as a popular platform for many applications, including those in chemistry and analytical sciences. In this work, we present our implementation of a new NMR 'app' designed for hand-held and portable touch-controlled devices, such as smartphones and tablets. It features a flexible architecture formed by a powerful NMR processing and analysis kernel and an intuitive user interface that makes full use of the smart devices haptic capabilities. Routine 1D and 2D NMR spectra acquired in most NMR instruments can be processed in a fully unattended way. More advanced experiments such as non-uniform sampled NMR spectra are also supported through a very efficient parallelized Modified Iterative Soft Thresholding algorithm. Specific technical development features as well as the overall feasibility of using NMR software apps will also be discussed. All aspects considered the functionalities of the app allowing it to work as a stand-alone tool or as a 'companion' to more advanced desktop applications such as Mnova NMR. Copyright © 2015 John Wiley & Sons, Ltd.

  3. CASD-NMR 2: robust and accurate unsupervised analysis of raw NOESY spectra and protein structure determination with UNIO

    International Nuclear Information System (INIS)

    Guerry, Paul; Duong, Viet Dung; Herrmann, Torsten

    2015-01-01

    UNIO is a comprehensive software suite for protein NMR structure determination that enables full automation of all NMR data analysis steps involved—including signal identification in NMR spectra, sequence-specific backbone and side-chain resonance assignment, NOE assignment and structure calculation. Within the framework of the second round of the community-wide stringent blind NMR structure determination challenge (CASD-NMR 2), we participated in two categories of CASD-NMR 2, namely using either raw NMR spectra or unrefined NOE peak lists as input. A total of 15 resulting NMR structure bundles were submitted for 9 out of 10 blind protein targets. All submitted UNIO structures accurately coincided with the corresponding blind targets as documented by an average backbone root mean-square deviation to the reference proteins of only 1.2 Å. Also, the precision of the UNIO structure bundles was virtually identical to the ensemble of reference structures. By assessing the quality of all UNIO structures submitted to the two categories, we find throughout that only the UNIO–ATNOS/CANDID approach using raw NMR spectra consistently yielded structure bundles of high quality for direct deposition in the Protein Data Bank. In conclusion, the results obtained in CASD-NMR 2 are another vital proof for robust, accurate and unsupervised NMR data analysis by UNIO for real-world applications

  4. Complete 1H NMR spectral analysis of ten chemical markers of Ginkgo biloba.

    Science.gov (United States)

    Napolitano, José G; Lankin, David C; Chen, Shao-Nong; Pauli, Guido F

    2012-08-01

    The complete and unambiguous (1)H NMR assignments of ten marker constituents of Ginkgo biloba are described. The comprehensive (1)H NMR profiles (fingerprints) of ginkgolide A, ginkgolide B, ginkgolide C, ginkgolide J, bilobalide, quercetin, kaempferol, isorhamnetin, isoquercetin, and rutin in DMSO-d(6) were obtained through the examination of 1D (1)H NMR and 2D (1)H,(1)H-COSY data, in combination with (1)H iterative full spin analysis (HiFSA). The computational analysis of discrete spin systems allowed a detailed characterization of all the (1)H NMR signals in terms of chemical shifts (δ(H)) and spin-spin coupling constants (J(HH)), regardless of signal overlap and higher order coupling effects. The capability of the HiFSA-generated (1)H fingerprints to reproduce experimental (1)H NMR spectra at different field strengths was also evaluated. As a result of this analysis, a revised set of (1)H NMR parameters for all ten phytoconstituents was assembled. Furthermore, precise (1)H NMR assignments of the sugar moieties of isoquercetin and rutin are reported for the first time. Copyright © 2012 John Wiley & Sons, Ltd.

  5. Automics: an integrated platform for NMR-based metabonomics spectral processing and data analysis

    Directory of Open Access Journals (Sweden)

    Qu Lijia

    2009-03-01

    Full Text Available Abstract Background Spectral processing and post-experimental data analysis are the major tasks in NMR-based metabonomics studies. While there are commercial and free licensed software tools available to assist these tasks, researchers usually have to use multiple software packages for their studies because software packages generally focus on specific tasks. It would be beneficial to have a highly integrated platform, in which these tasks can be completed within one package. Moreover, with open source architecture, newly proposed algorithms or methods for spectral processing and data analysis can be implemented much more easily and accessed freely by the public. Results In this paper, we report an open source software tool, Automics, which is specifically designed for NMR-based metabonomics studies. Automics is a highly integrated platform that provides functions covering almost all the stages of NMR-based metabonomics studies. Automics provides high throughput automatic modules with most recently proposed algorithms and powerful manual modules for 1D NMR spectral processing. In addition to spectral processing functions, powerful features for data organization, data pre-processing, and data analysis have been implemented. Nine statistical methods can be applied to analyses including: feature selection (Fisher's criterion, data reduction (PCA, LDA, ULDA, unsupervised clustering (K-Mean and supervised regression and classification (PLS/PLS-DA, KNN, SIMCA, SVM. Moreover, Automics has a user-friendly graphical interface for visualizing NMR spectra and data analysis results. The functional ability of Automics is demonstrated with an analysis of a type 2 diabetes metabolic profile. Conclusion Automics facilitates high throughput 1D NMR spectral processing and high dimensional data analysis for NMR-based metabonomics applications. Using Automics, users can complete spectral processing and data analysis within one software package in most cases

  6. Automics: an integrated platform for NMR-based metabonomics spectral processing and data analysis.

    Science.gov (United States)

    Wang, Tao; Shao, Kang; Chu, Qinying; Ren, Yanfei; Mu, Yiming; Qu, Lijia; He, Jie; Jin, Changwen; Xia, Bin

    2009-03-16

    Spectral processing and post-experimental data analysis are the major tasks in NMR-based metabonomics studies. While there are commercial and free licensed software tools available to assist these tasks, researchers usually have to use multiple software packages for their studies because software packages generally focus on specific tasks. It would be beneficial to have a highly integrated platform, in which these tasks can be completed within one package. Moreover, with open source architecture, newly proposed algorithms or methods for spectral processing and data analysis can be implemented much more easily and accessed freely by the public. In this paper, we report an open source software tool, Automics, which is specifically designed for NMR-based metabonomics studies. Automics is a highly integrated platform that provides functions covering almost all the stages of NMR-based metabonomics studies. Automics provides high throughput automatic modules with most recently proposed algorithms and powerful manual modules for 1D NMR spectral processing. In addition to spectral processing functions, powerful features for data organization, data pre-processing, and data analysis have been implemented. Nine statistical methods can be applied to analyses including: feature selection (Fisher's criterion), data reduction (PCA, LDA, ULDA), unsupervised clustering (K-Mean) and supervised regression and classification (PLS/PLS-DA, KNN, SIMCA, SVM). Moreover, Automics has a user-friendly graphical interface for visualizing NMR spectra and data analysis results. The functional ability of Automics is demonstrated with an analysis of a type 2 diabetes metabolic profile. Automics facilitates high throughput 1D NMR spectral processing and high dimensional data analysis for NMR-based metabonomics applications. Using Automics, users can complete spectral processing and data analysis within one software package in most cases. Moreover, with its open source architecture, interested

  7. Fourier Analysis and Structure Determination. Part II: Pulse NMR and NMR Imaging.

    Science.gov (United States)

    Chesick, John P.

    1989-01-01

    Uses simple pulse NMR experiments to discuss Fourier transforms. Studies the generation of spin echoes used in the imaging procedure. Shows that pulse NMR experiments give signals that are additions of sinusoids of differing amplitudes, frequencies, and phases. (MVL)

  8. NMR-based approach to the analysis of radiopharmaceuticals: radiochemical purity, specific activity, and radioactive concentration values by proton and tritium NMR spectroscopy.

    Science.gov (United States)

    Schenk, David J; Dormer, Peter G; Hesk, David; Pollack, Scott R; Lavey, Carolee Flader

    2015-06-15

    Compounds containing tritium are widely used across the drug discovery and development landscape. These materials are widely utilized because they can be efficiently synthesized and produced at high specific activity. Results from internally calibrated (3)H and (1)H nuclear magnetic resonance (NMR) spectroscopy suggests that at least in some cases, this calibrated approach could supplement or potentially replace radio-high-performance liquid chromatography for radiochemical purity, dilution and scintillation counting for the measurement of radioactivity per volume, and liquid chromatography/mass spectrometry analysis for the determination of specific activity. In summary, the NMR-derived values agreed with those from the standard approaches to within 1% to 9% for solution count and specific activity. Additionally, the NMR-derived values for radiochemical purity deviated by less than 5%. A benefit of this method is that these values may be calculated at the same time that (3)H NMR analysis provides the location and distribution of tritium atoms within the molecule. Presented and discussed here is the application of this method, advantages and disadvantages of the approach, and a rationale for utilizing internally calibrated (1)H and (3)H NMR spectroscopy for specific activity, radioactive concentration, and radiochemical purity whenever acquiring (3)H NMR for tritium location. Copyright © 2015 John Wiley & Sons, Ltd.

  9. Evaluation of algorithms for analysis of NMR relaxation decay curves

    NARCIS (Netherlands)

    Weerd, van der L.; Vergeldt, F.J.; Jager, de P.A.; As, van H.

    2000-01-01

    Quantitative processing of NMR relaxation images depends on the characteristics of the used fitting algorithm. Therefore several common fitting algorithms are compared for decay curves with low signal-to-noise ratios. The use of magnitude data yields a non-zero base line, and is shown to result in

  10. [Optimization of experimental parameters for quantitative NMR (qNMR) and its application in quantitative analysis of traditional Chinese medicines].

    Science.gov (United States)

    Ma, Xiao-Li; Zou, Ping-Ping; Lei, Wei; Tu, Peng-Fei; Jiang, Yong

    2014-09-01

    Quantitative NMR (qNMR) is a technology based on the principle of NMR. This technology does not need the references of the determined components, which supplies a solution for the problem of reference scarcity in the quantitative analysis of traditional Chinese medicines. Moreover, this technology has the advantages of easy operation, non-destructiveness for the determined sample, high accuracy and repeatability, in comparison with HPLC, LC-MS and GC-MS. NMR technology has achieved quantum leap in sensitivity and accuracy with the development of NMR hardware. In addition, the choice of appropriate experimental parameters of the pre-treatment and measurement procedure as well as the post-acquisition processing is also important for obtaining high-quality and reproducible NMR spectra. This review summarizes the principle of qHNMR, the various experimental parameters affecting the accuracy and the precision of qHNMR, such as signal to noise ratio, relaxation delay, pulse width, acquisition time, window function, phase correction and baseline correction, and their corresponding optimized methods. Moreover, the application of qHNMR in the fields of quantitation of single or multi-components of traditional Chinese medicines, the purity detection of references, and the quality analysis of foods has been discussed. In addition, the existing questions and the future application prospects of qNMR in natural product areas are also presented.

  11. Comprehensive NMR analysis of compositional changes of black garlic during thermal processing.

    Science.gov (United States)

    Liang, Tingfu; Wei, Feifei; Lu, Yi; Kodani, Yoshinori; Nakada, Mitsuhiko; Miyakawa, Takuya; Tanokura, Masaru

    2015-01-21

    Black garlic is a processed food product obtained by subjecting whole raw garlic to thermal processing that causes chemical reactions, such as the Maillard reaction, which change the composition of the garlic. In this paper, we report a nuclear magnetic resonance (NMR)-based comprehensive analysis of raw garlic and black garlic extracts to determine the compositional changes resulting from thermal processing. (1)H NMR spectra with a detailed signal assignment showed that 38 components were altered by thermal processing of raw garlic. For example, the contents of 11 l-amino acids increased during the first step of thermal processing over 5 days and then decreased. Multivariate data analysis revealed changes in the contents of fructose, glucose, acetic acid, formic acid, pyroglutamic acid, cycloalliin, and 5-(hydroxymethyl)furfural (5-HMF). Our results provide comprehensive information on changes in NMR-detectable components during thermal processing of whole garlic.

  12. Supramolecular chemical shift reagents inducing conformational transitions: NMR analysis of carbohydrate homooligomer mixtures

    DEFF Research Database (Denmark)

    Beeren, Sophie; Meier, Sebastian

    2015-01-01

    We introduce the concept of supramolecular chemical shift reagents as a tool to improve signal resolution for the NMR analysis of homooligomers. Non-covalent interactions with the shift reagent can constrain otherwise flexible analytes inducing a conformational transition that results in signal s...

  13. The fluorescence properties and NMR analysis of protopine and allocryptopine

    Energy Technology Data Exchange (ETDEWEB)

    Kubala, Martin, E-mail: mkubala@prfnw.upol.c [Department of Biophysics, Faculty of Science, Palacky University, tr. 17. listopadu 12, CZ-77146 Olomouc (Czech Republic); Vacek, Jan [Department of Medical Chemistry and Biochemistry, Faculty of Medicine and Dentistry, Palacky University, Hnevotinska 3, CZ-77515 Olomouc (Czech Republic); Popa, Igor [Department of Inorganic Chemistry, Faculty of Science, Palacky University, tr. 17. listopadu 12, CZ-77146 Olomouc (Czech Republic); Janovska, Marika [Department of Biophysics, Faculty of Science, Palacky University, tr. 17. listopadu 12, CZ-77146 Olomouc (Czech Republic); Kosina, Pavel; Ulrichova, Jitka [Department of Medical Chemistry and Biochemistry, Faculty of Medicine and Dentistry, Palacky University, Hnevotinska 3, CZ-77515 Olomouc (Czech Republic); Travnicek, Zdenek [Department of Inorganic Chemistry, Faculty of Science, Palacky University, tr. 17. listopadu 12, CZ-77146 Olomouc (Czech Republic); Simanek, Vilim [Department of Medical Chemistry and Biochemistry, Faculty of Medicine and Dentistry, Palacky University, Hnevotinska 3, CZ-77515 Olomouc (Czech Republic)

    2011-07-15

    The fluorescence properties of protopine and allocryptopine in aqueous and organic environments are described for the first time. The fluorescence of alkaloids and their pH-dependent interconversion to cationic forms (transannular interaction) were studied using steady-state and time-resolved fluorescence techniques. For the analysis of tricyclic base and cis/trans tetracyclic cations of the alkaloids, NMR and X-ray crystallography were used. - Highlights: {yields} We describe fundamental fluorescence characteristics of alkaloids protopine and allocryptopine. {yields} We analyzed the pH-dependent transitions and cis/trans isomerization. {yields} These two alkaloids can be better distinguished by their fluorescence decay characteristics. {yields} The fluorescence parameters are related to the NMR and crystallographic structural data.

  14. Quali- and quantitative analysis of commercial coffee by NMR

    International Nuclear Information System (INIS)

    Tavares, Leila Aley; Ferreira, Antonio Gilberto

    2006-01-01

    Coffee is one of the beverages most widely consumed in the world and the 'cafezinho' is normally prepared from a blend of roasted powder of two species, Coffea arabica and Coffea canephora. Each one exhibits differences in their taste and in the chemical composition, especially in the caffeine percentage. There are several procedures proposed in the literature for caffeine determination in different samples like soft drinks, coffee, medicines, etc but most of them need a sample workup which involves at least one step of purification. This work describes the quantitative analysis of caffeine using 1 H NMR and the identification of the major components in commercial coffee samples using 1D and 2D NMR techniques without any sample pre-treatment. (author)

  15. Automatic differential analysis of NMR experiments in complex samples.

    Science.gov (United States)

    Margueritte, Laure; Markov, Petar; Chiron, Lionel; Starck, Jean-Philippe; Vonthron-Sénécheau, Catherine; Bourjot, Mélanie; Delsuc, Marc-André

    2017-11-20

    Liquid state nuclear magnetic resonance (NMR) is a powerful tool for the analysis of complex mixtures of unknown molecules. This capacity has been used in many analytical approaches: metabolomics, identification of active compounds in natural extracts, and characterization of species, and such studies require the acquisition of many diverse NMR measurements on series of samples. Although acquisition can easily be performed automatically, the number of NMR experiments involved in these studies increases very rapidly, and this data avalanche requires to resort to automatic processing and analysis. We present here a program that allows the autonomous, unsupervised processing of a large corpus of 1D, 2D, and diffusion-ordered spectroscopy experiments from a series of samples acquired in different conditions. The program provides all the signal processing steps, as well as peak-picking and bucketing of 1D and 2D spectra, the program and its components are fully available. In an experiment mimicking the search of a bioactive species in a natural extract, we use it for the automatic detection of small amounts of artemisinin added to a series of plant extracts and for the generation of the spectral fingerprint of this molecule. This program called Plasmodesma is a novel tool that should be useful to decipher complex mixtures, particularly in the discovery of biologically active natural products from plants extracts but can also in drug discovery or metabolomics studies. Copyright © 2017 John Wiley & Sons, Ltd.

  16. LC-NMR Technique in the Analysis of Phytosterols in Natural Extracts

    Directory of Open Access Journals (Sweden)

    Štěpán Horník

    2013-01-01

    Full Text Available The ability of LC-NMR to detect simultaneously free and conjugated phytosterols in natural extracts was tested. The advantages and disadvantages of a gradient HPLC-NMR method were compared to the fast composition screening using SEC-NMR method. Fractions of free and conjugated phytosterols were isolated and analyzed by isocratic HPLC-NMR methods. The results of qualitative and quantitative analyses were in a good agreement with the literature data.

  17. Chemometric analysis of ESIMS and NMR data from Piper species

    International Nuclear Information System (INIS)

    Yamaguchi, Lydia F.; Freitas, Giovana C.; Yoshida, Nidia C.; Silva, Renata A.; Gaia, Anderson M.; Silva, Adalberto M.; Kato, Massuo J.; Emerenciano, Vicente de P.; Scotti, Marcus T.; Guimaraes, Elsie F.; Floh, Eny I.S.; Colombo, Carlos A.; Siqueira, Walter J.

    2011-01-01

    The metabolomic profiling based on the application of multivariate analysis (principal component analysis, PCA) of positive mode electrospray ionization mass spectrometric (ESIMS) and 1 H nuclear magnetic resonance (NMR) data of crude extracts highlighted some species characterized by lignans (P. solmsianum, P. truncatum and P. cernuum), neolignans (P. regnellii) and chromenes (P. gaudichaudianum). A specific analysis focusing on species having pendant and globular inflorescences (P. caldense, P. carniconnectivum, P. bowiei and P. permucronatum) or amides-producing species indicated higher potential of the methodology in determining similarities and establishing priorities for further phytochemical investigation. Such intraspecific analysis applied to analyzed seedling leaves of the P. solmsianum, P. regnellii and P. gaudichaudianum species revealed the production of dillapiole and apiole instead of lignans, neolignans or prenylated benzoic acid, produced by the adult leaves, respectively. In case of amides-producing species, a similar profile was observed regardless the developmental stage. (author)

  18. Chemometric analysis of ESIMS and NMR data from Piper species

    Energy Technology Data Exchange (ETDEWEB)

    Yamaguchi, Lydia F.; Freitas, Giovana C.; Yoshida, Nidia C.; Silva, Renata A.; Gaia, Anderson M.; Silva, Adalberto M.; Kato, Massuo J.; Emerenciano, Vicente de P., E-mail: majokato@iq.usp.br [Departamento de Quimica Fundamental, Instituto de Quimica, Universidade de Sao Paulo, SP (Brazil); Scotti, Marcus T. [Centro de Ciencias Aplicadas e Educacao (Campus IV), Universidade Federal da Paraiba, Rio Tinto, PB (Brazil); Guimaraes, Elsie F. [Instituto de Pesquisas Jardim Botanico do Rio de Janeiro, RJ (Brazil); Floh, Eny I.S. [Departamento de Botanica, Instituto de Biociencias, Sao Paulo, SP (Brazil); Colombo, Carlos A.; Siqueira, Walter J. [Centro de Genetica Biologia Molecular e Fitoquimica, Instituto Agronomico de Campinas, SP (Brazil)

    2011-09-15

    The metabolomic profiling based on the application of multivariate analysis (principal component analysis, PCA) of positive mode electrospray ionization mass spectrometric (ESIMS) and {sup 1}H nuclear magnetic resonance (NMR) data of crude extracts highlighted some species characterized by lignans (P. solmsianum, P. truncatum and P. cernuum), neolignans (P. regnellii) and chromenes (P. gaudichaudianum). A specific analysis focusing on species having pendant and globular inflorescences (P. caldense, P. carniconnectivum, P. bowiei and P. permucronatum) or amides-producing species indicated higher potential of the methodology in determining similarities and establishing priorities for further phytochemical investigation. Such intraspecific analysis applied to analyzed seedling leaves of the P. solmsianum, P. regnellii and P. gaudichaudianum species revealed the production of dillapiole and apiole instead of lignans, neolignans or prenylated benzoic acid, produced by the adult leaves, respectively. In case of amides-producing species, a similar profile was observed regardless the developmental stage. (author)

  19. Comparative quantitative analysis of artemisinin by chromatography and qNMR.

    Science.gov (United States)

    Liu, Ning Qing; Choi, Young Hae; Verpoorte, Robert; van der Kooy, Frank

    2010-01-01

    Since the discovery of artemisinin in the 1970s, many techniques based on diverse chromatography techniques have been developed to detect and quantify this important antiplasmodial compound. The accurate quantification of this compound in the Artemisia annua plant material is mainly needed for breeding purposes in order to cultivate higher yielding varieties. It is also important for the quality control of herbal preparations containing A. annua plant material. To evaluate the most common validated quantification techniques (LC-MS, HPLC-ELSD and TLC) and compare the results to quantitative nuclear magnetic resonance spectroscopy (qNMR) in eight different A. annua samples collected from around the world. The leaf material were extracted according to standard procedures and analysed with the validated quantification techniques. For the qNMR analysis we did not employ a standard curve but instead used an internal standard (maleid acid) which is not chemically related to artemisinin. We found a significant difference between the results in this study. Compared with the qNMR results the HPLC-ELSD corresponded closely, followed by LC-MS. Quantitation with TLC led to an estimation range of -0.5 to +3.2 mg artemisinin/g of A. annua. These results imply that qNMR, with the addition of an internal standard, can be used to quantify artemisinin in A. annua samples in a rapid and reproducible manner. Copyright © 2010 John Wiley & Sons, Ltd.

  20. Structures of glycans bound to receptors from saturation transfer difference (STD) NMR spectroscopy: quantitative analysis by using CORCEMA-ST.

    Science.gov (United States)

    Enríquez-Navas, Pedro M; Guzzi, Cinzia; Muñoz-García, Juan C; Nieto, Pedro M; Angulo, Jesús

    2015-01-01

    Glycan-receptor interactions are of fundamental relevance for a large number of biological processes, and their kinetics properties (medium/weak binding affinities) make them appropriated to be studied by ligand observed NMR techniques, among which saturation transfer difference (STD) NMR spectroscopy has been shown to be a very robust and powerful approach. The quantitative analysis of the results from a STD NMR study of a glycan-receptor interaction is essential to be able to translate the resulting spectral intensities into a 3D molecular model of the complex. This chapter describes how to carry out such a quantitative analysis by means of the Complete Relaxation and Conformational Exchange Matrix Approach for STD NMR (CORCEMA-ST), in general terms, and an example of a previous work on an antibody-glycan interaction is also shown.

  1. 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

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    Science.gov (United States)

    Monakhova, Yulia B; Godelmann, Rolf; Hermann, Armin; Kuballa, Thomas; Cannet, Claire; Schäfer, Hartmut; Spraul, Manfred; Rutledge, Douglas N

    2014-06-23

    It is known that (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 (1)H NMR profiles are fused with stable isotope (SNIF-NMR, (18)O, (13)C) data. Variable selection based on clustering of latent variables was performed on (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 (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 (1)H NMR data alone in 82-89% respectively). Certain enhancement was obtained also for the year of vintage (from 88 to 97% for (1)H NMR to 99% for the fused data), whereas in case of grape varieties improved models were not obtained. The combination of (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. Copyright © 2014 Elsevier B.V. All rights reserved.

  3. Simplified "No-D" NMR Methods for Routine Analysis and Organometallic Reagent Concentration Determination.

    Science.gov (United States)

    Fallon, Thomas; Meek, Tamaryn

    2017-11-03

    The use of tetrachloroethylene spiked with tetramethylsilane as a solvent for routine NMR analysis has been evaluated. Excellent quality spectra are reliably obtained, comparable to samples run in chloroform-d. Validation of this method is presented, together with the spectral data of commonly encountered trace impurities. In addition, NMR analysis for the concentration determination of organometallic reagents has been simplified using double-walled NMR tubes using a calibrated external reference solution within a hermetically sealed chamber.

  4. HR MAS 1H NMR spectroscopy analysis of marine microalgal whole cells

    OpenAIRE

    Chauton, Matilde S.; Optun, Odd Inge; Bathen, Tone F.; Volent, Zsolt; Gribbestad, Ingrid S.; Johnsen, Geir

    2003-01-01

    To study the use of nuclear magnetic resonance (NMR) spectroscopy as a method of classification, we performed high-resolution magic angle spinning proton (HR MAS 1H) NMR spectroscopy analysis of whole-cell samples of Dunaliella sp. (Chlorophyceae), Amphidinium carterae (Dinophyceae), Phaeodactylum tricornutum and Thalassiosira pseudonana (Bacillariophyceae). Emphasising the potential use of NMR spectroscopy as a routine analysis of microalgae we chose a straightforward procedure for culturing...

  5. Conformational analysis of capsaicin using 13C, 15N MAS NMR, GIAO DFT and GA calculations

    Science.gov (United States)

    Siudem, Paweł; Paradowska, Katarzyna; Bukowicki, Jarosław

    2017-10-01

    Capsaicin produced by plants from genus Capsicum exerts multiple pharmacological effects and has found applications in food and pharmaceutical industry. The alkaloid was studied by a combined approach: solid-state NMR, GA conformational search and GIAO DFT methods. The 13C CPMAS NMR spectra were recorded using variable contact time and dipolar dephasing experiments. The results of cross-polarization (CP) kinetics, such as TCP values and long T1ρH (100-200 ms), indicated that the capsaicin molecule is fairly mobile, especially at the end of the aliphatic chain. The15N MAS NMR spectrum showed one narrow signal at -255 ppm. Genetic algorithm (GA) search with multi modal optimization was used to find low-energy conformations of capsaicin. Theoretical GIAO DFT calculations were performed using different basis sets to characterize five selected conformations. 13C CPMAS NMR was used as a validation method and the experimental chemical shifts were compared with those calculated for selected stable conformers. Conformational analysis suggests that the side chain can be bent or extended. A comparison of the experimental and the calculated chemical shifts indicates that solid capsaicin does not have the same structure as those established by PWXRD.

  6. An integrated workflow for robust alignment and simplified quantitative analysis of NMR spectrometry data

    Directory of Open Access Journals (Sweden)

    Dommisse Roger

    2011-10-01

    Full Text Available Abstract Background Nuclear magnetic resonance spectroscopy (NMR is a powerful technique to reveal and compare quantitative metabolic profiles of biological tissues. However, chemical and physical sample variations make the analysis of the data challenging, and typically require the application of a number of preprocessing steps prior to data interpretation. For example, noise reduction, normalization, baseline correction, peak picking, spectrum alignment and statistical analysis are indispensable components in any NMR analysis pipeline. Results We introduce a novel suite of informatics tools for the quantitative analysis of NMR metabolomic profile data. The core of the processing cascade is a novel peak alignment algorithm, called hierarchical Cluster-based Peak Alignment (CluPA. The algorithm aligns a target spectrum to the reference spectrum in a top-down fashion by building a hierarchical cluster tree from peak lists of reference and target spectra and then dividing the spectra into smaller segments based on the most distant clusters of the tree. To reduce the computational time to estimate the spectral misalignment, the method makes use of Fast Fourier Transformation (FFT cross-correlation. Since the method returns a high-quality alignment, we can propose a simple methodology to study the variability of the NMR spectra. For each aligned NMR data point the ratio of the between-group and within-group sum of squares (BW-ratio is calculated to quantify the difference in variability between and within predefined groups of NMR spectra. This differential analysis is related to the calculation of the F-statistic or a one-way ANOVA, but without distributional assumptions. Statistical inference based on the BW-ratio is achieved by bootstrapping the null distribution from the experimental data. Conclusions The workflow performance was evaluated using a previously published dataset. Correlation maps, spectral and grey scale plots show clear

  7. Functional Analysis of the Nitrogen Metabolite Repression Regulator Gene nmrA in Aspergillus flavus

    Directory of Open Access Journals (Sweden)

    Xiaoyun Han

    2016-11-01

    Full Text Available In Aspergillus nidulans, the nitrogen metabolite repression regulator NmrA plays a major role in regulating the activity of the GATA transcription factor AreA during nitrogen metabolism. However, the function of nmrA in Aspergillus flavus has notbeen previously studied. Here, we report the identification and functional analysis of nmrA in A. flavus. Our work showed that the amino acid sequences of NmrA are highly conserved among Aspergillus species and that A. flavus NmrA protein contains a canonical Rossmann fold motif. Deletion of nmrA slowed the growth of A. flavus but significantly increased conidiation and sclerotia production. Moreover, seed infection experiments indicated that nmrA is required for the invasive virulence of A. flavus. In addition, the ΔnmrA mutant showed increased sensitivity to rapamycin and methyl methanesulfonate, suggesting that nmrA could be responsive to target of rapamycin signaling and DNA damage. Furthermore, quantitative real-time reverse transcription polymerase chain reaction analysis suggested that nmrA might interact with other nitrogen regulatory and catabolic genes. Our study provides a better understanding of nitrogen metabolite repression and the nitrogen metabolism network in fungi.

  8. NMR-Based Metabolomic Analysis of Spatial Variation in Soft Corals

    Directory of Open Access Journals (Sweden)

    Qing He

    2014-03-01

    Full Text Available Soft corals are common marine organisms that inhabit tropical and subtropical oceans. They are shown to be rich source of secondary metabolites with biological activities. In this work, soft corals from two geographical locations were investigated using 1H-NMR spectroscopy coupled with multivariate statistical analysis at the metabolic level. A partial least-squares discriminant analysis showed clear separation among extracts of soft corals grown in Sanya Bay and Weizhou Island. The specific markers that contributed to discrimination between soft corals in two origins belonged to terpenes, sterols and N-containing compounds. The satisfied precision of classification obtained indicates this approach using combined 1H-NMR and chemometrics is effective to discriminate soft corals collected in different geographical locations. The results revealed that metabolites of soft corals evidently depended on living environmental condition, which would provide valuable information for further relevant coastal marine environment evaluation.

  9. Metabolomic differentiation of maca (Lepidium meyenii) accessions cultivated under different conditions using NMR and chemometric analysis.

    Science.gov (United States)

    Zhao, Jianping; Avula, Bharathi; Chan, Michael; Clément, Céline; Kreuzer, Michael; Khan, Ikhlas A

    2012-01-01

    To gain insights on the effects of color type, cultivation history, and growing site on the composition alterations of maca (Lepidium meyenii Walpers) hypocotyls, NMR profiling combined with chemometric analysis was applied to investigate the metabolite variability in different maca accessions. Maca hypocotyls with different colors (yellow, pink, violet, and lead-colored) cultivated at different geographic sites and different areas were examined for differences in metabolite expression. Differentiations of the maca accessions grown under the different cultivation conditions were determined by principle component analyses (PCAs) which were performed on the datasets derived from their ¹H NMR spectra. A total of 16 metabolites were identified by NMR analysis, and the changes in metabolite levels in relation to the color types and growing conditions of maca hypocotyls were evaluated using univariate statistical analysis. In addition, the changes of the correlation pattern among the metabolites identified in the maca accessions planted at the two different sites were examined. The results from both multivariate and univariate analysis indicated that the planting site was the major determining factor with regards to metabolite variations in maca hypocotyls, while the color of maca accession seems to be of minor importance in this respect. © Georg Thieme Verlag KG Stuttgart · New York.

  10. NMR bioreactor development for live in-situ microbial functional analysis

    Science.gov (United States)

    Majors, Paul D.; McLean, Jeffrey S.; Scholten, Johannes C. M.

    2008-05-01

    A live, in-situ metabolomics capability was developed for prokaryotic cultures under controlled growth conditions. Toward this goal, a radiofrequency-transparent bioreactor was developed and integrated with a commercial wide-bore nuclear magnetic resonance (NMR) imaging spectrometer and a commercial bioreactor controller. Water suppressed 1H NMR spectroscopy was used to monitor glucose and fructose utilization and byproduct excretion by Eubacterium aggregans (an anaerobic bacterial species relevant for biofuel production) under controlled batch and continuous culture conditions. The resulting metabolite profiles (short chain organic acids and ethanol) and trends are consistent with existing knowledge of its metabolism. However, our study also showed that E. aggregans produces lactate end product in significant concentrations—a result not previously reported. The advantages of live in-situ microbial metabolomics analysis and its complementariness with functional genomics/systems biology methods are discussed.

  11. NMR-based urine analysis in rats: prediction of proximal tubule kidney toxicity and phospholipidosis.

    Science.gov (United States)

    Lienemann, Kai; Plötz, Thomas; Pestel, Sabine

    2008-01-01

    The aim of safety pharmacology is early detection of compound-induced side-effects. NMR-based urine analysis followed by multivariate data analysis (metabonomics) identifies efficiently differences between toxic and non-toxic compounds; but in most cases multiple administrations of the test compound are necessary. We tested the feasibility of detecting proximal tubule kidney toxicity and phospholipidosis with metabonomics techniques after single compound administration as an early safety pharmacology approach. Rats were treated orally, intravenously, inhalatively or intraperitoneally with different test compounds. Urine was collected at 0-8 h and 8-24 h after compound administration, and (1)H NMR-patterns were recorded from the samples. Variation of post-processing and feature extraction methods led to different views on the data. Support Vector Machines were trained on these different data sets and then aggregated as experts in an Ensemble. Finally, validity was monitored with a cross-validation study using a training, validation, and test data set. Proximal tubule kidney toxicity could be predicted with reasonable total classification accuracy (85%), specificity (88%) and sensitivity (78%). In comparison to alternative histological studies, results were obtained quicker, compound need was reduced, and very importantly fewer animals were needed. In contrast, the induction of phospholipidosis by the test compounds could not be predicted using NMR-based urine analysis or the previously published biomarker PAG. NMR-based urine analysis was shown to effectively predict proximal tubule kidney toxicity after single compound administration in rats. Thus, this experimental design allows early detection of toxicity risks with relatively low amounts of compound in a reasonably short period of time.

  12. NMR analysis of male fathead minnow urinary metabolites: A potential approach for studying impacts of chemical exposures

    Energy Technology Data Exchange (ETDEWEB)

    Ekman, D.R. [Ecosystems Research Division, U.S. EPA, 960 College Station Road, Athens, GA 30605 (United States)], E-mail: ekman.drew@epa.gov; Teng, Q. [Ecosystems Research Division, U.S. EPA, 960 College Station Road, Athens, GA 30605 (United States); Jensen, K.M.; Martinovic, D.; Villeneuve, D.L.; Ankley, G.T. [Mid-Continent Ecology Division, U.S. EPA, 6201 Congdon Boulevard, Duluth, MN 55804 (United States); Collette, T.W. [Ecosystems Research Division, U.S. EPA, 960 College Station Road, Athens, GA 30605 (United States)

    2007-11-30

    The potential for profiling metabolites in urine from male fathead minnows (Pimephales promelas) to assess chemical exposures was explored using nuclear magnetic resonance (NMR) spectroscopy. Both one-dimensional (1D) and two-dimensional (2D) NMR spectroscopy was used for the assignment of metabolites in urine from unexposed fish. Because fathead minnow urine is dilute, we lyophilized these samples prior to analysis. Furthermore, 1D {sup 1}H NMR spectra of unlyophilized urine from unexposed male fathead minnow and Sprague-Dawley rat were acquired to qualitatively compare rat and fish metabolite profiles and to provide an estimate of the total urinary metabolite pool concentration difference. As a small proof-of-concept study, lyophilized urine samples from male fathead minnows exposed to three different concentrations of the antiandrogen vinclozolin were analyzed by 1D {sup 1}H NMR to assess exposure-induced changes. Through a combination of principal components analysis (PCA) and measurements of {sup 1}H NMR peak intensities, several metabolites were identified as changing with statistical significance in response to exposure. Among those changes occurring in response to exposure to the highest concentration (450 {mu}g/L) of vinclozolin were large increases in taurine, lactate, acetate, and formate. These increases coincided with a marked decrease in hippurate, a combination potentially indicative of hepatotoxicity. The results of these investigations clearly demonstrate the potential utility of an NMR-based approach for assessing chemical exposures in male fathead minnow, using urine collected from individual fish.

  13. New insight into the microtexture of chalks from NMR analysis

    DEFF Research Database (Denmark)

    Faÿ-Gomord, Ophélie; Soete, Jeroen; Katika, Konstantina

    2016-01-01

    An integrated petrographical and petrophysical study was carried out on a set of 35 outcrop chalk samples, covering a wide range of lithologies and textures. In this study various chalk rock-types have been characterized, in terms of microtextures and porous network, by integrating both geological...... quality chalks independently of their sedimentological and/or diagenetic history. The study aims to develop an NMR-based approach to characterize a broad range of chalk samples. The provided laboratory low-field NMR chalk classification can be used as a guide to interpret NMR logging data...

  14. Reliability of ^1^H NMR analysis for assessment of lipid oxidation at frying temperatures

    Science.gov (United States)

    The reliability of a method using ^1^H NMR analysis for assessment of oil oxidation at a frying temperature was examined. During heating and frying at 180 °C, changes of soybean oil signals in the ^1^H NMR spectrum including olefinic (5.16-5.30 ppm), bisallylic (2.70-2.88 ppm), and allylic (1.94-2.1...

  15. Factor analysis of 27Al MAS NMR spectra for identifying nanocrystalline phases in amorphous geopolymers

    Czech Academy of Sciences Publication Activity Database

    Urbanová, Martina; Kobera, Libor; Brus, Jiří

    2013-01-01

    Roč. 51, č. 11 (2013), s. 734-742 ISSN 0749-1581 R&D Projects: GA ČR(CZ) GA13-24155S Institutional support: RVO:61389013 Keywords : solid-state NMR * 27Al MAS NMR * factor analysis Subject RIV: JN - Civil Engineering Impact factor: 1.559, year: 2013

  16. GUARDD: user-friendly MATLAB software for rigorous analysis of CPMG RD NMR data.

    Science.gov (United States)

    Kleckner, Ian R; Foster, Mark P

    2012-01-01

    Molecular dynamics are essential for life, and nuclear magnetic resonance (NMR) spectroscopy has been used extensively to characterize these phenomena since the 1950s. For the past 15 years, the Carr-Purcell Meiboom-Gill relaxation dispersion (CPMG RD) NMR experiment has afforded advanced NMR labs access to kinetic, thermodynamic, and structural details of protein and RNA dynamics in the crucial μs-ms time window. However, analysis of RD data is challenging because datasets are often large and require many non-linear fitting parameters, thereby confounding assessment of accuracy. Moreover, novice CPMG experimentalists face an additional barrier because current software options lack an intuitive user interface and extensive documentation. Hence, we present the open-source software package GUARDD (Graphical User-friendly Analysis of Relaxation Dispersion Data), which is designed to organize, automate, and enhance the analytical procedures which operate on CPMG RD data ( http://code.google.com/p/guardd/). This MATLAB-based program includes a graphical user interface, permits global fitting to multi-field, multi-temperature, multi-coherence data, and implements χ (2)-mapping procedures, via grid-search and Monte Carlo methods, to enhance and assess fitting accuracy. The presentation features allow users to seamlessly traverse the large amount of results, and the RD Simulator feature can help design future experiments as well as serve as a teaching tool for those unfamiliar with RD phenomena. Based on these innovative features, we expect that GUARDD will fill a well-defined gap in service of the RD NMR community.

  17. Whole-core analysis by 13C NMR

    International Nuclear Information System (INIS)

    Vinegar, H.J.; Tutunjian, P.N.; Edelstein, W.A.; Roemer, P.B.

    1991-01-01

    This paper reports on a whole-core nuclear magnetic resonance (NMR) system that was used to obtain natural abundance 13 C spectra. The system enables rapid, nondestructive measurements of bulk volume of movable oil, aliphatic/aromatic ratio, oil viscosity, and organic vs. carbonate carbon. 13 C NMR can be used in cores where the 1 H NMR spectrum is too broad to resolve oil and water resonances separately. A 5 1/4-in. 13 C/ 1 H NMR coil was installed on a General Electric (GE) CSI-2T NMR imager/spectrometer. With a 4-in.-OD whole core, good 13 C signal/noise ratio (SNR) is obtained within minutes, while 1 H spectra are obtained in seconds. NMR measurements have been made of the 13 C and 1 H density of crude oils with a wide range of API gravities. For light- and medium-gravity oils, the 13 C and 1 H signal per unit volume is constant within about 3.5%. For heavy crudes, the 13 C and 1 H density measured by NMR is reduced by the shortening of spin-spin relaxation time. 13 C and 1 H NMR spin-lattice relaxation times were measured on a suite of Cannon viscosity standards, crude oils (4 to 60 degrees API), and alkanes (C 5 through C 16 ) with viscosities at 77 degrees F ranging from 0.5 cp to 2.5 x 10 7 cp. The 13 C and 1 H relaxation times show a similar correlation with viscosity from which oil viscosity can be estimated accurately for viscosities up to 100 cp. The 13 C surface relaxation rate for oils on water-wet rocks is very low. Nonproton decoupled 13 C NMR is shown to be insensitive to kerogen; thus, 13 C NMR measures only the movable hydrocarbon content of the cores. In carbonates, the 13 C spectrum also contains a carbonate powder pattern useful in quantifying inorganic carbon and distinguishing organic from carbonate carbon

  18. NMR guided focused ultrasound for myoma therapy - results from the first radiology-gynecology expert meeting

    International Nuclear Information System (INIS)

    Beck, A.; Charite Universitaetsmedizin Berlin, Campus Virchow-Klinikum, Berlin; David, M.; Kroencke, T.; Charite Universitaetsmedizin Berlin, Campus Charite Mitte, Berlin

    2013-01-01

    The contribution on the results from the first radiology-gynecology expert meeting concerning NMR guided focused ultrasound (MRgFUS) for myoma therapy covers the following topics: structural prerequisites for MRgFUS therapy; required examinations before MRgFUS therapy; indication for MRgFUS therapy; success criteria for the MRgFUS therapy; contraindications; MRgFUS therapy for patients that want to have children; side effects and complications of MRgFUS therapy; post-examination after MRgFUS therapy.

  19. Analysis of 2D NMR relaxation data using Chisholm approximations.

    Science.gov (United States)

    Huber, S; Haase, A; Gleich, B

    2017-08-01

    To analyze 2D NMR relaxation data based on a discrete delta-like relaxation map we extended the Padé-Laplace method to two dimensions. We approximate the forward Laplace image of the time domain signal by a Chisholm approximation, i.e. a rational polynomial in two dimensions. The poles and residues of this approximation correspond to the relaxation rates and weighting factors of the underlying relaxation map. In this work we explain the principle ideas of our algorithm and demonstrate its applicability. Therefore we compare the inversion results of the Chisholm approximation and Tikhonov regularization method as a function of SNR when the investigated signal is based on a given discrete relaxation map. Our algorithm proved to be reliable for SNRs larger than 50 and is able to compete with the Tikhonov regularization method. Furthermore we show that our method is also able to detect the simulated relaxation compartments of narrow Gaussian distributions with widths less or equal than 0.05s -1 . Finally we investigate the resolution limit with experimental data. For a SNR of 750 the Chisholm approximation method was able to resolve two relaxation compartments in 8 of 10 cases when both compartments differ by a factor of 1.7. Copyright © 2017 Elsevier Inc. All rights reserved.

  20. Complete 1H NMR spectral analysis of ten chemical markers of Ginkgo biloba

    OpenAIRE

    Napolitano, José G.; Lankin, David C.; Chen, Shao-Nong; Pauli, Guido F.

    2012-01-01

    The complete and unambiguous 1H NMR assignments of ten marker constituents of Ginkgo biloba are described. The comprehensive 1H NMR profiles (fingerprints) of ginkgolide A, ginkgolide B, ginkgolide C, ginkgolide J, bilobalide, quercetin, kaempferol, isorhamnetin, isoquercetin, and rutin in DMSO-d6 were obtained through the examination of 1D 1H NMR and 2D 1H,1H-COSY data, in combination with 1H iterative Full Spin Analysis (HiFSA). The computational analysis of discrete spin systems allowed a ...

  1. Variable-temperature NMR and conformational analysis of Oenothein B

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Suzana C.; Carvalho, Ariadne G.; Fortes, Gilmara A.C.; Ferri, Pedro H.; Oliveira, Anselmo E. de, E-mail: suzana.quimica.ufg@hotmail.com [Universidade Federal de Goias (UFGO), Goiania, GO (Brazil). Instituto de Quimica

    2014-02-15

    Oenothein B is a dimeric hydrolyzable tannin with a wide range of biological activities, such as antitumour, anti-inflammatory and antiviral. Its nuclear magnetic resonance (NMR) at room temperature show duplications and broadening of signals. Experiments of 1D and 2D NMR at lower temperatures were useful for the complete NMR assignments of all hydrogens and carbons. The 3D structure of the most stable conformer was determined for the first time by nuclear Overhauser effect spectroscopy (NOESY) experiment (-20 deg C) and density functional theory (DFT)(B3LYP/6-31G)/ polarizable continuum model (PCM) quantum chemical calculations. The favoured conformation showed a highly compacted geometry and a lack of symmetry, in which the two valoneoyl groups showed distinct conformational parameters and stabilities. (author)

  2. NMR analysis of silk for the interpretation of ancient history

    International Nuclear Information System (INIS)

    Chujo, Riichiro

    1998-01-01

    The aim of this paper is the characterization of archaeological silk with the aid of nuclear magnetic resonance (NMR). In this paper the nucleus is confined to 13C as a stable isotope carbon which is the most basic element in organic compounds. Among the stable carbon isotopes 12C is the most abundant but it has no magnetic moment and the natural abundance of 13C is only 1.108% and this isotope is frequently used in NMR due to its non-zero magnetic moment

  3. Spectral analysis, vibrational assignments, NBO analysis, NMR, UV-Vis, hyperpolarizability analysis of 2-aminofluorene by density functional theory.

    Science.gov (United States)

    Jone Pradeepa, S; Sundaraganesan, N

    2014-05-05

    In this present investigation, the collective experimental and theoretical study on molecular structure, vibrational analysis and NBO analysis has been reported for 2-aminofluorene. FT-IR spectrum was recorded in the range 4000-400 cm(-1). FT-Raman spectrum was recorded in the range 4000-50 cm(-1). The molecular geometry, vibrational spectra, and natural bond orbital analysis (NBO) were calculated for 2-aminofluorene using Density Functional Theory (DFT) based on B3LYP/6-31G(d,p) model chemistry. (13)C and (1)H NMR chemical shifts of 2-aminofluorene were calculated using GIAO method. The computed vibrational and NMR spectra were compared with the experimental results. The total energy distribution (TED) was derived to deepen the understanding of different modes of vibrations contributed by respective wavenumber. The experimental UV-Vis spectra was recorded in the region of 400-200 nm and correlated with simulated spectra by suitably solvated B3LYP/6-31G(d,p) model. The HOMO-LUMO energies were measured with time dependent DFT approach. The nonlinearity of the title compound was confirmed by hyperpolarizabilty examination. Using theoretical calculation Molecular Electrostatic Potential (MEP) was investigated. Copyright © 2014 Elsevier B.V. All rights reserved.

  4. DFT molecular modeling and NMR conformational analysis of a new longipinenetriolone diester

    Science.gov (United States)

    Cerda-García-Rojas, Carlos M.; Guerra-Ramírez, Diana; Román-Marín, Luisa U.; Hernández-Hernández, Juan D.; Joseph-Nathan, Pedro

    2006-05-01

    The structure and conformational behavior of the new natural compound (4 R,5 S,7 S,8 R,9 S,10 R,11 R)-longipin-2-en-7,8,9-triol-1-one 7-angelate-9-isovalerate (1) isolated from Stevia eupatoria, were studied by molecular modeling and NMR spectroscopy. A Monte Carlo search followed by DFT calculations at the B3LYP/6-31G* level provided the theoretical conformations of the sesquiterpene framework, which were in full agreement with results derived from the 1H- 1H coupling constant analysis.

  5. A route to quantitative 13C NMR analysis of multicomponent polyesters

    DEFF Research Database (Denmark)

    Hvilsted, S.

    1991-01-01

    A protocol for quantitative sequential 13C NMR analysis is developed for polyesters composed of trimethylol propane (TMP), neopentyl glycol (NPG), and adipic and isophthalic acids. TMP centred, structural models with methyl adipate and isophthalate branches in all possible combinations are synthe......A protocol for quantitative sequential 13C NMR analysis is developed for polyesters composed of trimethylol propane (TMP), neopentyl glycol (NPG), and adipic and isophthalic acids. TMP centred, structural models with methyl adipate and isophthalate branches in all possible combinations...

  6. HIGH FIELD 13C NMR SPECTROSCOPIC ANALYSIS OF THE ...

    African Journals Online (AJOL)

    a

    2 carbon atoms of Sat in the β and α glyceridic positions. The. 34.114 ppm ... Table 1. 13C NMR chemical shifts of Jatropha curcas oil. Chemical shift (ppm). Assignment. 173.388. C-1, Sat. 173.302. C-1, O, L (α). 172.887. C-1, O, L (β). 34.223.

  7. Crystallinity and compositional changes in carbonated apatites: Evidence from {sup 31}P solid-state NMR, Raman, and AFM analysis

    Energy Technology Data Exchange (ETDEWEB)

    McElderry, John-David P.; Zhu, Peizhi [Department of Chemistry, University of Michigan, Ann Arbor, MI 48109-1055 (United States); Mroue, Kamal H. [Department of Chemistry, University of Michigan, Ann Arbor, MI 48109-1055 (United States); Department of Biophysics, University of Michigan, Ann Arbor, MI 48109-1055 (United States); Xu, Jiadi [Department of Biophysics, University of Michigan, Ann Arbor, MI 48109-1055 (United States); Pavan, Barbara [Department of Chemistry and Science of Advanced Materials Program, Central Michigan University, Mt. Pleasant, MI 48859 (United States); Fang, Ming [Department of Chemistry, University of Michigan, Ann Arbor, MI 48109-1055 (United States); Zhao, Guisheng; McNerny, Erin; Kohn, David H.; Franceschi, Renny T. [School of Dentistry, University of Michigan, Ann Arbor, MI 48109-1055 (United States); Holl, Mark M.Banaszak [Department of Chemistry, University of Michigan, Ann Arbor, MI 48109-1055 (United States); Tecklenburg, Mary M.J., E-mail: mary.tecklenburg@cmich.edu [Department of Chemistry and Science of Advanced Materials Program, Central Michigan University, Mt. Pleasant, MI 48859 (United States); Ramamoorthy, Ayyalusamy [Department of Chemistry, University of Michigan, Ann Arbor, MI 48109-1055 (United States); Department of Biophysics, University of Michigan, Ann Arbor, MI 48109-1055 (United States); Morris, Michael D. [Department of Chemistry, University of Michigan, Ann Arbor, MI 48109-1055 (United States)

    2013-10-15

    Solid-state (magic-angle spinning) NMR spectroscopy is a useful tool for obtaining structural information on bone organic and mineral components and synthetic model minerals at the atomic-level. Raman and {sup 31}P NMR spectral parameters were investigated in a series of synthetic B-type carbonated apatites (CAps). Inverse {sup 31}P NMR linewidth and inverse Raman PO{sub 4}{sup 3−}ν{sub 1} bandwidth were both correlated with powder XRD c-axis crystallinity over the 0.3–10.3 wt% CO{sub 3}{sup 2−} range investigated. Comparison with bone powder crystallinities showed agreement with values predicted by NMR and Raman calibration curves. Carbonate content was divided into two domains by the {sup 31}P NMR chemical shift frequency and the Raman phosphate ν{sub 1} band position. These parameters remain stable except for an abrupt transition at 6.5 wt% carbonate, a composition which corresponds to an average of one carbonate per unit cell. This near-binary distribution of spectroscopic properties was also found in AFM-measured particle sizes and Ca/P molar ratios by elemental analysis. We propose that this transition differentiates between two charge-balancing ion-loss mechanisms as measured by Ca/P ratios. These results define a criterion for spectroscopic characterization of B-type carbonate substitution in apatitic minerals. - Graphical abstract: Carbonated apatite shows an abrupt change in spectral (NMR, Raman) and morphological (AFM) properties at a composition of about one carbonate substitution per unit cell. Display Omitted - Highlights: • Crystallinity (XRD), particle size (AFM) of carbonated apatites and bone mineral. • Linear relationships among crystallinity, {sup 31}P NMR and Raman inverse bandwidths. • Low and high carbonated apatites use different charge-balancing ion-loss mechanism.

  8. Implementation of picoSpin Benchtop NMR Instruments into Organic Chemistry Teaching Laboratories through Spectral Analysis of Fischer Esterification Products

    Science.gov (United States)

    Yearty, Kasey L.; Sharp, Joseph T.; Meehan, Emma K.; Wallace, Doyle R.; Jackson, Douglas M.; Morrison, Richard W.

    2017-01-01

    [Superscript 1]H NMR analysis is an important analytical technique presented in introductory organic chemistry courses. NMR instrument access is limited for undergraduate organic chemistry students due to the size of the instrument, price of NMR solvents, and the maintenance level required for instrument upkeep. The University of Georgia Chemistry…

  9. Reproducibility of NMR Analysis of Urine Samples: Impact of Sample Preparation, Storage Conditions, and Animal Health Status

    Directory of Open Access Journals (Sweden)

    Christina Schreier

    2013-01-01

    Full Text Available Introduction. Spectroscopic analysis of urine samples from laboratory animals can be used to predict the efficacy and side effects of drugs. This employs methods combining 1H NMR spectroscopy with quantification of biomarkers or with multivariate data analysis. The most critical steps in data evaluation are analytical reproducibility of NMR data (collection, storage, and processing and the health status of the animals, which may influence urine pH and osmolarity. Methods. We treated rats with a solvent, a diuretic, or a nephrotoxicant and collected urine samples. Samples were titrated to pH 3 to 9, or salt concentrations increased up to 20-fold. The effects of storage conditions and freeze-thaw cycles were monitored. Selected metabolites and multivariate data analysis were evaluated after 1H NMR spectroscopy. Results. We showed that variation of pH from 3 to 9 and increases in osmolarity up to 6-fold had no effect on the quantification of the metabolites or on multivariate data analysis. Storage led to changes after 14 days at 4°C or after 12 months at −20°C, independent of sample composition. Multiple freeze-thaw cycles did not affect data analysis. Conclusion. Reproducibility of NMR measurements is not dependent on sample composition under physiological or pathological conditions.

  10. Isotopomer analysis of lipid biosynthesis by high resolution mass spectrometry and NMR

    Energy Technology Data Exchange (ETDEWEB)

    Lane, Andrew N., E-mail: anlane01@louisville.edu [JG Brown Cancer Center, 529 S. Jackson Street, Louisville, KY 40202 (United States); Center for Regulatory and Environmental Analytical Metabolomics (CREAM), University of Louisville, Louisville, KY (United States); Fan, Teresa W.-M. [JG Brown Cancer Center, 529 S. Jackson Street, Louisville, KY 40202 (United States); Center for Regulatory and Environmental Analytical Metabolomics (CREAM), University of Louisville, Louisville, KY (United States); Department of Chemistry, University of Louisville, Louisville, KY 40292 (United States); Xie, Zhengzhi; Moseley, Hunter N.B.; Higashi, Richard M. [Center for Regulatory and Environmental Analytical Metabolomics (CREAM), University of Louisville, Louisville, KY (United States); Department of Chemistry, University of Louisville, Louisville, KY 40292 (United States)

    2009-10-05

    We have coupled 2D-NMR and infusion FT-ICR-MS with computer-assisted assignment to profile {sup 13}C-isotopologues of glycerophospholipids (GPL) directly in crude cell extracts, resulting in very high information throughput of >3000 isobaric molecules in a few minutes. A mass accuracy of better than 1 ppm combined with a resolution of 100,000 at the measured m/z was required to distinguish isotopomers from other GPL structures. Isotopologue analysis of GPLs extracted from LCC2 breast cancer cells grown on [U-{sup 13}C]-glucose provided a rich trove of information about the biosynthesis and turnover of the GPLs. The isotopologue intensity ratios from the FT-ICR-MS were accurate to {approx}1% or better based on natural abundance background, and depended on the signal-to-nose ratio. The time course of incorporation of {sup 13}C from [U-{sup 13}C]-glucose into a particular phosphatidylcholine was analyzed in detail, to provide a quantitative measure of the sizes of glycerol, acetyl CoA and total GPL pools in growing LCC2 cells. Independent and complementary analysis of the positional {sup 13}C enrichment in the glycerol and fatty acyl chains obtained from high resolution 2D NMR was used to verify key aspects of the model. This technology enables simple and rapid sample preparation, has rapid analysis, and is generally applicable to unfractionated GPLs of almost any head group, and to mixtures of other classes of metabolites.

  11. Isotopomer analysis of lipid biosynthesis by high resolution mass spectrometry and NMR

    International Nuclear Information System (INIS)

    Lane, Andrew N.; Fan, Teresa W.-M.; Xie, Zhengzhi; Moseley, Hunter N.B.; Higashi, Richard M.

    2009-01-01

    We have coupled 2D-NMR and infusion FT-ICR-MS with computer-assisted assignment to profile 13 C-isotopologues of glycerophospholipids (GPL) directly in crude cell extracts, resulting in very high information throughput of >3000 isobaric molecules in a few minutes. A mass accuracy of better than 1 ppm combined with a resolution of 100,000 at the measured m/z was required to distinguish isotopomers from other GPL structures. Isotopologue analysis of GPLs extracted from LCC2 breast cancer cells grown on [U- 13 C]-glucose provided a rich trove of information about the biosynthesis and turnover of the GPLs. The isotopologue intensity ratios from the FT-ICR-MS were accurate to ∼1% or better based on natural abundance background, and depended on the signal-to-nose ratio. The time course of incorporation of 13 C from [U- 13 C]-glucose into a particular phosphatidylcholine was analyzed in detail, to provide a quantitative measure of the sizes of glycerol, acetyl CoA and total GPL pools in growing LCC2 cells. Independent and complementary analysis of the positional 13 C enrichment in the glycerol and fatty acyl chains obtained from high resolution 2D NMR was used to verify key aspects of the model. This technology enables simple and rapid sample preparation, has rapid analysis, and is generally applicable to unfractionated GPLs of almost any head group, and to mixtures of other classes of metabolites.

  12. Analysis of seven-membered lactones by computational NMR methods: proton NMR chemical shift data are more discriminating than carbon.

    Science.gov (United States)

    Marell, Daniel J; Emond, Susanna J; Kulshrestha, Aman; Hoye, Thomas R

    2014-01-17

    We report an NMR chemical shift study of conformationally challenging seven-membered lactones (1-11); computed and experimental data sets are compared. The computations involved full conformational analysis of each lactone, Boltzmann-weighted averaging of the chemical shifts across all conformers, and linear correction of the computed chemical shifts. DFT geometry optimizations [M06-2X/6-31+G(d,p)] and GIAO NMR chemical shift calculations [B3LYP/6-311+G(2d,p)] provided the computed chemical shifts. The corrected mean absolute error (CMAE), the average of the differences between the computed and experimental chemical shifts for each of the 11 lactones, is encouragingly small (0.02-0.08 ppm for (1)H or 0.8-2.2 ppm for (13)C). Three pairs of cis versus trans diastereomeric lactones were used to assess the ability of the method to distinguish between stereoisomers. The experimental shifts were compared with the computed shifts for each of the two possible isomers. We introduce the use of a "match ratio"--the ratio of the larger CMAE (worse fit) to the smaller CMAE (better fit). A greater match ratio value indicates better distinguishing ability. The match ratios are larger for proton data [2.4-4.0 (av = 3.2)] than for carbon [1.1-2.3 (av = 1.6)], indicating that the former provide a better basis for discriminating these diastereomers.

  13. Use of optimized 1D TOCSY NMR for improved quantitation and metabolomic analysis of biofluids

    International Nuclear Information System (INIS)

    Sandusky, Peter; Appiah-Amponsah, Emmanuel; Raftery, Daniel

    2011-01-01

    One dimensional selective TOCSY experiments have been shown to be advantageous in providing improved data inputs for principle component analysis (PCA) (Sandusky and Raftery 2005a, b). Better subpopulation cluster resolution in the observed scores plots results from the ability to isolate metabolite signals of interest via the TOCSY based filtering approach. This report reexamines the quantitative aspects of this approach, first by optimizing the 1D TOCSY experiment as it relates to the measurement of biofluid constituent concentrations, and second by comparing the integration of 1D TOCSY read peaks to the bucket integration of 1D proton NMR spectra in terms of precision and accuracy. This comparison indicates that, because of the extensive peak overlap that occurs in the 1D proton NMR spectra of biofluid samples, bucket integrals are often far less accurate as measures of individual constituent concentrations than 1D TOCSY read peaks. Even spectral fitting approaches have proven difficult in the analysis of significantly overlapped spectral regions. Measurements of endogenous taurine made over a sample population of human urine demonstrates that, due to background signals from other constituents, bucket integrals of 1D proton spectra routinely overestimate the taurine concentrations and distort its variation over the sample population. As a result, PCA calculations performed using data matrices incorporating 1D TOCSY determined taurine concentrations produce better scores plot subpopulation cluster resolution.

  14. Use of optimized 1D TOCSY NMR for improved quantitation and metabolomic analysis of biofluids

    Energy Technology Data Exchange (ETDEWEB)

    Sandusky, Peter [Eckerd College, Department of Chemistry (United States); Appiah-Amponsah, Emmanuel; Raftery, Daniel, E-mail: raftery@purdue.edu [Purdue University, Department of Chemistry (United States)

    2011-04-15

    One dimensional selective TOCSY experiments have been shown to be advantageous in providing improved data inputs for principle component analysis (PCA) (Sandusky and Raftery 2005a, b). Better subpopulation cluster resolution in the observed scores plots results from the ability to isolate metabolite signals of interest via the TOCSY based filtering approach. This report reexamines the quantitative aspects of this approach, first by optimizing the 1D TOCSY experiment as it relates to the measurement of biofluid constituent concentrations, and second by comparing the integration of 1D TOCSY read peaks to the bucket integration of 1D proton NMR spectra in terms of precision and accuracy. This comparison indicates that, because of the extensive peak overlap that occurs in the 1D proton NMR spectra of biofluid samples, bucket integrals are often far less accurate as measures of individual constituent concentrations than 1D TOCSY read peaks. Even spectral fitting approaches have proven difficult in the analysis of significantly overlapped spectral regions. Measurements of endogenous taurine made over a sample population of human urine demonstrates that, due to background signals from other constituents, bucket integrals of 1D proton spectra routinely overestimate the taurine concentrations and distort its variation over the sample population. As a result, PCA calculations performed using data matrices incorporating 1D TOCSY determined taurine concentrations produce better scores plot subpopulation cluster resolution.

  15. Simultaneous Gaussian and exponential inversion for improved analysis of shales by NMR relaxometry

    Science.gov (United States)

    Washburn, Kathryn E.; Anderssen, Endre; Vogt, Sarah J.; Seymour, Joseph D.; Birdwell, Justin E.; Kirkland, Catherine M.; Codd, Sarah L.

    2014-01-01

    Nuclear magnetic resonance (NMR) relaxometry is commonly used to provide lithology-independent porosity and pore-size estimates for petroleum resource evaluation based on fluid-phase signals. However in shales, substantial hydrogen content is associated with solid and fluid signals and both may be detected. Depending on the motional regime, the signal from the solids may be best described using either exponential or Gaussian decay functions. When the inverse Laplace transform, the standard method for analysis of NMR relaxometry results, is applied to data containing Gaussian decays, this can lead to physically unrealistic responses such as signal or porosity overcall and relaxation times that are too short to be determined using the applied instrument settings. We apply a new simultaneous Gaussian-Exponential (SGE) inversion method to simulated data and measured results obtained on a variety of oil shale samples. The SGE inversion produces more physically realistic results than the inverse Laplace transform and displays more consistent relaxation behavior at high magnetic field strengths. Residuals for the SGE inversion are consistently lower than for the inverse Laplace method and signal overcall at short T2 times is mitigated. Beyond geological samples, the method can also be applied in other fields where the sample relaxation consists of both Gaussian and exponential decays, for example in material, medical and food sciences.

  16. Simultaneous Gaussian and exponential inversion for improved analysis of shales by NMR relaxometry

    Science.gov (United States)

    Washburn, Kathryn E.; Anderssen, Endre; Vogt, Sarah J.; Seymour, Joseph D.; Birdwell, Justin E.; Kirkland, Catherine M.; Codd, Sarah L.

    2015-01-01

    Nuclear magnetic resonance (NMR) relaxometry is commonly used to provide lithology-independent porosity and pore-size estimates for petroleum resource evaluation based on fluid-phase signals. However in shales, substantial hydrogen content is associated with solid and fluid signals and both may be detected. Depending on the motional regime, the signal from the solids may be best described using either exponential or Gaussian decay functions. When the inverse Laplace transform, the standard method for analysis of NMR relaxometry results, is applied to data containing Gaussian decays, this can lead to physically unrealistic responses such as signal or porosity overcall and relaxation times that are too short to be determined using the applied instrument settings. We apply a new simultaneous Gaussian-Exponential (SGE) inversion method to simulated data and measured results obtained on a variety of oil shale samples. The SGE inversion produces more physically realistic results than the inverse Laplace transform and displays more consistent relaxation behavior at high magnetic field strengths. Residuals for the SGE inversion are consistently lower than for the inverse Laplace method and signal overcall at short T2 times is mitigated. Beyond geological samples, the method can also be applied in other fields where the sample relaxation consists of both Gaussian and exponential decays, for example in material, medical and food sciences.

  17. Nmrglue: an open source Python package for the analysis of multidimensional NMR data

    International Nuclear Information System (INIS)

    Helmus, Jonathan J.; Jaroniec, Christopher P.

    2013-01-01

    Nmrglue, an open source Python package for working with multidimensional NMR data, is described. When used in combination with other Python scientific libraries, nmrglue provides a highly flexible and robust environment for spectral processing, analysis and visualization and includes a number of common utilities such as linear prediction, peak picking and lineshape fitting. The package also enables existing NMR software programs to be readily tied together, currently facilitating the reading, writing and conversion of data stored in Bruker, Agilent/Varian, NMRPipe, Sparky, SIMPSON, and Rowland NMR Toolkit file formats. In addition to standard applications, the versatility offered by nmrglue makes the package particularly suitable for tasks that include manipulating raw spectrometer data files, automated quantitative analysis of multidimensional NMR spectra with irregular lineshapes such as those frequently encountered in the context of biomacromolecular solid-state NMR, and rapid implementation and development of unconventional data processing methods such as covariance NMR and other non-Fourier approaches. Detailed documentation, install files and source code for nmrglue are freely available at http://nmrglue.comhttp://nmrglue.com. The source code can be redistributed and modified under the New BSD license.

  18. Phosphorus-31 NMR (nuclear magnetic resonance) analysis of gold plating baths

    Energy Technology Data Exchange (ETDEWEB)

    Smith, R.E.

    1990-01-01

    This report describes the nuclear magnetic resonance (NMR) analysis of the gold plating baths in the Micro-Miniature Electronic Assembly department of Allied-Signal Inc., Kansas City Division (KCD). The baths were analyzed for phosphorylated components. In freshly prepared gold plating baths, a 50-percent aqueous solution of aminotrimethylphosphonate (ATMP) is the principal compound observed. As the bath is used in production, the ATMP breaks down and new materials (phosphate, ADMP, and AMMP) are identified. The NMR method was used to monitor the concentrations of the ATMP and breakdown products for a nine-month period. The 225-liter bath had plated approximately 100 square feet of gold during the nine-month period. These results can be used to predict the performance of baths as they are used in production. The accuracy of the analysis is 96 percent for ATMP and 92 percent for phosphate. The precision (relative standard deviation) is 5.2 percent for ATMP and 4.5 percent for phosphate. 1 ref., 5 figs., 2 tabs.

  19. Parent heparin and daughter LMW heparin correlation analysis using LC-MS and NMR

    International Nuclear Information System (INIS)

    Liu, Xinyue; St Ange, Kalib; Wang, Xiaohua; Lin, Lei; Zhang, Fuming

    2017-01-01

    Heparin is a structurally complex, polysaccharide anticoagulant derived from livestock, primarily porcine intestinal tissues. Low molecular weight (LMW) heparins are derived through the controlled partial depolymerization of heparin. Increased manufacturing and regulatory concerns have provided the motivation for the development of more sophisticated analytical methods for determining both their structure and pedigree. A strategy, for the comprehensive comparison of parent heparins and their LMW heparin daughters, is described that relies on the analysis of monosaccharide composition, disaccharide composition, and oligosaccharide composition. Liquid chromatography-mass spectrometry is rapid, robust, and amenable to automated processing and interpretation of both top-down and bottom-up analyses. Nuclear magnetic resonance spectroscopy provides complementary top-down information on the chirality of the uronic acid residues and glucosamine substitution. Principal component analysis (PCA) was applied to the normalized abundance of oligosaccharides, calculated in the bottom-up analysis, to show parent and daughter correlation in oligosaccharide composition. Using these approaches, six pairs of parent heparins and their daughter generic enoxaparins from two different manufacturers were comprehensively analyzed. Enoxaparin is the most widely used LMW heparin and is prepared through controlled chemical β-eliminative cleavage of porcine intestinal heparin. Lovenox ® , the innovator version of enoxaparin marketed in the US, was analyzed as a reference for the daughter LMW heparins. The results, show similarities between LMW heparins from two different manufacturers with Lovenox ® , excellent lot-to-lot consistency of products from each manufacturer, and detects a correlation between each parent heparin and daughter LMW heparin. - Highlights: • Low molecular weight heparins prepared from different heparin parents were analyzed. • An integrated analytical approach

  20. Parent heparin and daughter LMW heparin correlation analysis using LC-MS and NMR

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Xinyue, E-mail: liux22@rpi.edu [National Glycoengineering Research Center, Shandong Provincial Key Laboratory of Carbohydrate Chemistry and Glycobiology, State Key Laboratory of Microbial Technology, Shandong University, Jinan, Shandong, 250100 (China); Department of Chemistry and Chemical Biology, Department of Chemical and Biological Engineering, Department of Biology, Department of Biomedical Engineering, Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, NY, 12180 (United States); St Ange, Kalib, E-mail: stangk2@rpi.edu [Department of Chemistry and Chemical Biology, Department of Chemical and Biological Engineering, Department of Biology, Department of Biomedical Engineering, Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, NY, 12180 (United States); Wang, Xiaohua, E-mail: wangx35@rpi.edu [Department of Chemistry and Chemical Biology, Department of Chemical and Biological Engineering, Department of Biology, Department of Biomedical Engineering, Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, NY, 12180 (United States); School of Computer and Information, Hefei University of Technology, Hefei (China); Lin, Lei, E-mail: Linl5@rpi.edu [Department of Chemistry and Chemical Biology, Department of Chemical and Biological Engineering, Department of Biology, Department of Biomedical Engineering, Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, NY, 12180 (United States); Zhang, Fuming, E-mail: zhangf2@rpi.edu [Department of Chemistry and Chemical Biology, Department of Chemical and Biological Engineering, Department of Biology, Department of Biomedical Engineering, Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, NY, 12180 (United States); and others

    2017-04-08

    Heparin is a structurally complex, polysaccharide anticoagulant derived from livestock, primarily porcine intestinal tissues. Low molecular weight (LMW) heparins are derived through the controlled partial depolymerization of heparin. Increased manufacturing and regulatory concerns have provided the motivation for the development of more sophisticated analytical methods for determining both their structure and pedigree. A strategy, for the comprehensive comparison of parent heparins and their LMW heparin daughters, is described that relies on the analysis of monosaccharide composition, disaccharide composition, and oligosaccharide composition. Liquid chromatography-mass spectrometry is rapid, robust, and amenable to automated processing and interpretation of both top-down and bottom-up analyses. Nuclear magnetic resonance spectroscopy provides complementary top-down information on the chirality of the uronic acid residues and glucosamine substitution. Principal component analysis (PCA) was applied to the normalized abundance of oligosaccharides, calculated in the bottom-up analysis, to show parent and daughter correlation in oligosaccharide composition. Using these approaches, six pairs of parent heparins and their daughter generic enoxaparins from two different manufacturers were comprehensively analyzed. Enoxaparin is the most widely used LMW heparin and is prepared through controlled chemical β-eliminative cleavage of porcine intestinal heparin. Lovenox{sup ®}, the innovator version of enoxaparin marketed in the US, was analyzed as a reference for the daughter LMW heparins. The results, show similarities between LMW heparins from two different manufacturers with Lovenox{sup ®}, excellent lot-to-lot consistency of products from each manufacturer, and detects a correlation between each parent heparin and daughter LMW heparin. - Highlights: • Low molecular weight heparins prepared from different heparin parents were analyzed. • An integrated analytical

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

    International Nuclear Information System (INIS)

    Mutsaers, J.H.G.M.

    1986-01-01

    This thesis deals with the structural analysis by 500-MHz 1 H-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

  2. Enhancing metabolomic data analysis with Progressive Consensus Alignment of NMR Spectra (PCANS

    Directory of Open Access Journals (Sweden)

    O'Connell Thomas M

    2010-03-01

    Full Text Available Abstract Background Nuclear magnetic resonance spectroscopy is one of the primary tools in metabolomics analyses, where it is used to track and quantify changes in metabolite concentrations or profiles in response to perturbation through disease, toxicants or drugs. The spectra generated through such analyses are typically confounded by noise of various types, obscuring the signals and hindering downstream statistical analysis. Such issues are becoming increasingly significant as greater numbers of large-scale systems or longitudinal studies are being performed, in which many spectra from different conditions need to be compared simultaneously. Results We describe a novel approach, termed Progressive Consensus Alignment of Nmr Spectra (PCANS, for the alignment of NMR spectra. Through the progressive integration of many pairwise comparisons, this approach generates a single consensus spectrum as an output that is then used to adjust the chemical shift positions of the peaks from the original input spectra to their final aligned positions. We characterize the performance of PCANS by aligning simulated NMR spectra, which have been provided with user-defined amounts of chemical shift variation as well as inter-group differences as would be observed in control-treatment applications. Moreover, we demonstrate how our method provides better performance than either template-based alignment or binning. Finally, we further evaluate this approach in the alignment of real mouse urine spectra and demonstrate its ability to improve downstream PCA and PLS analyses. Conclusions By avoiding the use of a template or reference spectrum, PCANS allows for the creation of a consensus spectrum that enhances the signals within the spectra while maintaining sample-specific features. This approach is of greatest benefit when complex samples are being analyzed and where it is expected that there will be spectral features unique and/or strongly different between subgroups

  3. Structural analysis of the exopolysaccharide produced by Streptococcus thermophilus ST1 solely by NMR spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Saewen, Elin [Arrhenius Laboratory, Stockholm University, Department of Organic Chemistry (Sweden); Huttunen, Eine; Zhang Xue [University of Helsinki, Department of Food Technology (Finland); Yang Zhennai [Northeast Agricultural Research Center of China, Center of Agro-food Technology (China); Widmalm, Goeran, E-mail: gw@organ.su.s [Arrhenius Laboratory, Stockholm University, Department of Organic Chemistry (Sweden)

    2010-06-15

    The use of lactic acid bacteria in fermentation of milk results in favorable physical and rheological properties due to in situ exopolysaccharide (EPS) production. The EPS from S. thermophilus ST1 produces highly viscous aqueous solutions and its structure has been investigated by NMR spectroscopy. Notably, all aspects of the elucidation of its primary structure including component analysis and absolute configuration of the constituent monosaccharides were carried out by NMR spectroscopy. An array of techniques was utilized including, inter alia, PANSY and NOESY-HSQC TILT experiments. The EPS is composed of hexasaccharide repeating units with the following structure: {yields} 3)[{alpha}-d-Glcp-(1 {yields} 4)]-{beta}-d-Galp-(1 {yields} 4)-{beta}-d-Glcp-(1 {yields} 4)[{beta}-d-Galf-(1 {yields} 6)]-{beta}-d-Glcp-(1 {yields} 6)-{beta}-d-Glcp-(1 {sup {yields}}, in which the residues in square brackets are terminal groups substituting backbone sugar residues that consequently are branch-points in the repeating unit of the polymer. Thus, the EPS consists of a backbone of four sugar residues with two terminal sugar residues making up two side-chains of the repeating unit. The molecular mass of the polymer was determined using translational diffusion experiments which resulted in M{sub w} = 62 kDa, corresponding to 64 repeating units in the EPS.

  4. Structural analysis of the exopolysaccharide produced by Streptococcus thermophilus ST1 solely by NMR spectroscopy

    International Nuclear Information System (INIS)

    Saewen, Elin; Huttunen, Eine; Zhang Xue; Yang Zhennai; Widmalm, Goeran

    2010-01-01

    The use of lactic acid bacteria in fermentation of milk results in favorable physical and rheological properties due to in situ exopolysaccharide (EPS) production. The EPS from S. thermophilus ST1 produces highly viscous aqueous solutions and its structure has been investigated by NMR spectroscopy. Notably, all aspects of the elucidation of its primary structure including component analysis and absolute configuration of the constituent monosaccharides were carried out by NMR spectroscopy. An array of techniques was utilized including, inter alia, PANSY and NOESY-HSQC TILT experiments. The EPS is composed of hexasaccharide repeating units with the following structure: → 3)[α-d-Glcp-(1 → 4)]-β-d-Galp-(1 → 4)-β-d-Glcp-(1 → 4)[β-d-Galf-(1 → 6)]-β-d-Glcp-(1 → 6)-β-d-Glcp-(1 → , in which the residues in square brackets are terminal groups substituting backbone sugar residues that consequently are branch-points in the repeating unit of the polymer. Thus, the EPS consists of a backbone of four sugar residues with two terminal sugar residues making up two side-chains of the repeating unit. The molecular mass of the polymer was determined using translational diffusion experiments which resulted in M w = 62 kDa, corresponding to 64 repeating units in the EPS.

  5. A conformational NMR analysis of methymycin aglycones: complete and unambiguous assignments of stereochemically diverse glycosylated methymycin analogs by 1D and 2D NMR techniques and molecular modeling.

    Science.gov (United States)

    Akhmedov, Novruz G; Gannett, Peter M; Wu, Bulan; Cummings, Matthew M; Train, Brian C

    2013-03-01

    The (1)H and (13)C NMR spectra of 10-deoxymethynolide (1), 8.9-dihydro-10-deoxymethynolide (2) and its glycosylated derivatives (3-9) were analyzed using gradient-selected NMR techniques, including 1D TOCSY, gCOSY, 1D NOESY (DPFGSENOE), NOESY, gHMBC, gHSQC and gHSQC-TOCSY. The NMR spectral parameters (chemical shifts and coupling constants) of 1-9 were determined by iterative analysis. For the first time, complete and unambiguous assignment of the (1)H NMR spectrum of 10-deoxymethynolide (1) has been achieved in CDCl(3), CD(3)OD and C(6)D(6) solvents. The (1)H NMR spectrum of 8,9-dihydro-10-deoxymethynolide (2) was recorded in CDCl(3), (CD(3))(2)CO and CD(3)OD solutions to determine the conformation. NMR-based conformational analysis of 1 and 2 in conjugation with molecular modeling concluded that the 12-membered ring of the macrolactones may predominantly exist in a single stable conformation in all solvents examined. In all cases, a change in solvent caused only small changes in chemical shifts and coupling constants, suggesting that all glycosylated methymycin analogs exist with similar conformations of the aglycone ring in solution. Copyright © 2013 John Wiley & Sons, Ltd.

  6. The influence of a sample rotation on the NMR line shape - experimental results

    International Nuclear Information System (INIS)

    Blicharska, B.; Kruk, D.; Schneler, E.

    1995-01-01

    The rotated liquid sample NMR spectra has been measured. The hydrodynamical effects of the rotated liquid has been taken into account. The measured spectra show the asymmetry due to the different rotation frequency of different part of the sample

  7. NMR spectroscopic and analytical ultracentrifuge analysis of membrane protein detergent complexes

    Directory of Open Access Journals (Sweden)

    Choe Senyon

    2007-11-01

    Full Text Available Abstract Background Structural studies of integral membrane proteins (IMPs are hampered by inherent difficulties in their heterologous expression and in the purification of solubilized protein-detergent complexes (PDCs. The choice and concentrations of detergents used in an IMP preparation play a critical role in protein homogeneity and are thus important for successful crystallization. Results Seeking an effective and standardized means applicable to genomic approaches for the characterization of PDCs, we chose 1D-NMR spectroscopic analysis to monitor the detergent content throughout their purification: protein extraction, detergent exchange, and sample concentration. We demonstrate that a single NMR measurement combined with a SDS-PAGE of a detergent extracted sample provides a useful gauge of the detergent's extraction potential for a given protein. Furthermore, careful monitoring of the detergent content during the process of IMP production allows for a high level of reproducibility. We also show that in many cases a simple sedimentation velocity measurement provides sufficient data to estimate both the oligomeric state and the detergent-to-protein ratio in PDCs, as well as to evaluate the homogeneity of the samples prior to crystallization screening. Conclusion The techniques presented here facilitate the screening and selection of the extraction detergent, as well as help to maintain reproducibility in the detergent exchange and PDC concentration procedures. Such reproducibility is particularly important for the optimization of initial crystallization conditions, for which multiple purifications are routinely required.

  8. Quantitation in the solid-state 13C NMR analysis of soil and organic soil fractions.

    Science.gov (United States)

    Keeler, Camille; Maciel, Gary E

    2003-05-15

    13C CP-MAS and DP-MAS spin-counting experiments have been carried out on an absolute basis for a specific whole soil and its humin, humic acid, and fulvic acid fractions, as well as a sample of the soil that was treated with 2% HF(aq). The results confirm previous conclusions that a substantial fraction of the carbon content indicated by classic elemental analysis is missed in some samples, especially whole soil and humin, by both CP-MAS and DP-MAS 13C NMR methods, and that the problem is more serious for CP-MAS than for DP-MAS. This study also confirms the fact that treatment of soil organic matter with 2% HF(aq) dramatically reduces this problem but may generate some structural uncertainties associated with significant structural alterations that accompany the HF(aq) treatment, as indicated by the 13C NMR data. The relationship between the "missing carbon" problem and the concentration of paramagnetic centers, especially Fe(III) centers, is explored in substantial detail.

  9. Metabolic fingerprinting of Tussilago farfara L. using ¹H-NMR spectroscopy and multivariate data analysis.

    Science.gov (United States)

    Zhi, Hai-Juan; Qin, Xue-Mei; Sun, Hai-Feng; Zhang, Li-Zeng; Guo, Xiao-Qing; Li, Zhen-Yu

    2012-01-01

    The flower bud of Tussilago farfara L. is widely used for the treatment of coughs, bronchitis and asthmatic disorders in traditional Chinese medicine. In Europe, the plant has been used as herbal remedies for virtually the same applications, but the leaves are preferred over flowers. To systematically evaluate the chemical profiles of Tusssilago farfara leaves and flowers along with the identification of the polar and non-polar metabolites. Metabolic profiling carried out by means of ¹H-NMR spectroscopy and multivariate data analysis was applied to crude extracts from flowers and leaves. Metabolites were identified directly from the crude extracts through one-dimensional and two-dimensional NMR spectra. A broad range of metabolites were detected without any chromatographic separation. Principal component analysis (PCA) and partial least squares-discriminant analysis (PLS-DA) of ¹H-NMR data provided a clear separation between the samples. The corresponding loadings plot indicated that higher levels of phenylpropanoids, amino acids, organic acids and fatty acids, as well as lower levels of sugars, terpenoids and sterols were present in the leaves, as compared with flowers. For the flowers, more phenylpropanoids were present in fully open flowers, while more sugars and fatty acids were present in flower buds. NMR spectra (one- and two-dimensional) are useful for identifying metabolites, especially for the overlapped signals. The NMR-based metabolomics approach has great potential for chemical comparison study of the metabolome of herbal drugs. Copyright © 2012 John Wiley & Sons, Ltd.

  10. Extraction, Purification, and NMR Analysis of Terpenes from Brown Algae.

    Science.gov (United States)

    Gaysinski, Marc; Ortalo-Magné, Annick; Thomas, Olivier P; Culioli, Gérald

    2015-01-01

    Algal terpenes constitute a wide and well-documented group of marine natural products with structures differing from their terrestrial plant biosynthetic analogues. Amongst macroalgae, brown seaweeds are considered as one of the richest source of biologically and ecologically relevant terpenoids. These metabolites, mostly encountered in algae of the class Phaeophyceae, are mainly diterpenes and meroditerpenes (metabolites of mixed biogenesis characterized by a toluquinol or a toluquinone nucleus linked to a diterpene moiety).In this chapter, we describe analytical processes commonly employed for the isolation and structural characterization of the main terpenoid constituents obtained from organic extracts of brown algae. The successive steps include (1) extraction of lipidic content from algal samples; (2) purification of terpenes by column chromatography and semi-preparative high-performance liquid chromatography; and (3) structure elucidation of the isolated terpenes by means of 1D and 2D nuclear magnetic resonance (NMR). More precisely, we propose a representative methodology which allows the isolation and structural determination of the monocyclic meroditerpene methoxybifurcarenone (MBFC) from the Mediterranean brown alga Cystoseira amentacea var. stricta. This methodology has a large field of applications and can then be extended to terpenes isolated from other species of the family Sargassaceae.

  11. TLC and 31P-NMR analysis of low polarity phospholipids.

    Science.gov (United States)

    Vyssotski, Mikhail; MacKenzie, Andrew; Scott, Dawn

    2009-04-01

    High-performance TLC and (31)P-NMR were assessed as methods of observing the presence of numerous low polarity phospholipids: bis-phosphatidic acid (BPA), semi-lyso bis-phosphatidic acid (SLBPA), N-acyl phosphatidylethanolamine (NAPE), N-(1,1-dimethyl-3-oxo-butyl)-phosphatidylethanolamine (diacetone adduct of PE, DOBPE), N-acetyl PE, phosphatidylmethanol (PM), phosphatidylethanol (PEt), phosphatidyl-n-propanol (PP), phosphatidyl-n-butanol (PB). Both techniques are non-discriminative and do not require the prior isolation of individual lipids. It appears that 2D TLC is superior to (31)P NMR in the analysis of low polarity phospholipids. All phosphatidylalcohols were well separated by 2D TLC. However, some compounds which can present difficulty in separation by 2D-TLC (e.g., SLBPA and NAPE; or DOBPE and N-acetyl PE) were easily distinguished using (31)P NMR so the methods are complimentary. A disadvantage of 2D TLC is that Rf values can vary with different brands and batches of TLC plates. The chemical shifts of (31)P NMR were less variable, and so a library of standards may not be necessary for peak identification. Another advantage of (31)P NMR is the ease of quantification of phospholipids. The applicability of the methods was tested on natural extracts of fish brain and cabbage stem.

  12. Simultaneous analysis of amino acid and organic acid by NMR spectrometry, 2

    International Nuclear Information System (INIS)

    Koda, Naoya; Yamaguchi, Shuichi; Mori, Takeshi.

    1987-01-01

    Analysis of urine from patients with inborn error of metabolism were studied by 1 H-nuclear magnetic resonance (NMR) spectrometry. Diseases studied were as follows; phenylketonuria, biotin responsive multiple carboxylase deficiency, non-ketotic hyperglycinemia, 3-ketothiolase deficiency, alkaptonuria, methylmalonic acidemia, isovaleric acidemia, glutaric aciduria, argininosuccinic aciduria and hyperornithinemia. In each disease, specific metabolites in urine were recognized by NMR spectrometry. This method is accomplished within 10 minutes with non-treated small volume of urine and will be successfully available for the screening and/or diagnosis of inherited metabolic diseases of amino acid and organic acid. (author)

  13. Solid-state NMR in the analysis of drugs and naturally occurring materials.

    Science.gov (United States)

    Paradowska, Katarzyna; Wawer, Iwona

    2014-05-01

    This article presents some of the solid-state NMR (SSNMR) techniques used in the pharmaceutical and biomedical research. Solid-state magic angle spinning (MAS) NMR provides structural information on powder amorphous solids for which single-crystal diffraction structures cannot be obtained. NMR is non-destructive; the powder sample may be used for further studies. Quantitative results can be obtained, although solid-state NMR spectra are not normally quantitative. As compared with other techniques, MAS NMR is insensitive and requires a significant amount of the powder sample (2-100mg) to fill the 1.3-7 mm ZrO2 rotor. This is its main drawback, since natural compounds isolated from plants, microorganisms or cell cultures are difficult to obtain in quantities higher than a few milligrams. Multinuclear MAS NMR routinely uses (1)H and (13)C nuclei, less frequently (15)N, (19)F, (31)P, (77)Se, (29)Si, (43)Ca or (23)Na. The article focuses on the pharmaceutical applications of SSNMR, the studies were aimed to control over manufacturing processes (e.g. crystallization and milling) investigation of chemical and physical stability of solid forms both as pure drug and in a formulated product. SSNMR is used in combination with some other analytical methods (DSC, XRD, FT-IR) and theoretical calculations of NMR parameters. Biologically active compounds, such as amino acids and small peptides, steroids and flavonoids were studied by SSNMR methods (part 4) providing valuable structural information. The SSNMR experiments performed on biopolymers and large natural products like proteins, cellulose and lipid layers are commented upon briefly in part 5. Copyright © 2013 Elsevier B.V. All rights reserved.

  14. Bias and Uncertainty in Non-Ideal qNMR Analysis.

    Science.gov (United States)

    Le Gresley, Adam; Fardus, Fahmina; Warren, John

    2015-01-01

    We report a comprehensive analysis of the acquisition-related sources of uncertainty for internally and externally standardized qNMR experiments. The impacts of major instrument- and sample-related sources of biases and uncertainties are quantified where possible, and the validity of correction and calibration techniques are also discussed. The application of uncertainty budgets for qNMR is well established for simple, internally standardized systems, but the model is incomplete and does not allow for the additional biases and sources of uncertainty that arise from spectrum complexity and external standardization. This report considers the additional contributions to the uncertainty budget that need to be considered to ensure SI traceability of measurement across a wider range of analytes and NMR methodologies.

  15. Quantitative NMR of quadrupolar nucleus as a novel analytical method: hydrolysis behaviour analysis of aluminum ion.

    Science.gov (United States)

    Maki, Hideshi; Sakata, Genki; Mizuhata, Minoru

    2017-05-21

    In this study, quantitative nuclear magnetic resonance (qNMR) spectroscopy of quadrupolar nuclei has been established. The complicated hydrolysis behavior of the Al 3+ ion, which causes fish poisoning and inhibits the growth of plants in environmental water, was clarified by 27 Al qNMR spectroscopy. Highly accurate simultaneous multicomponent quantitative analysis of various hydrolyzed forms of the Al ion was achieved in a non-destructive manner. The calibration curve of the external standard aqueous Al(NO 3 ) 3 solution showed excellent linearity over a very wide concentration range from 1 × 10 -4 to 1 mol L -1 (an increase in concentration of 10 000 times), with a simple experimental and analytical procedure. Furthermore, the weaknesses of the conventional Ferron assay and the advantages of 27 Al qNMR spectroscopy were considered. The quantitative determination error for the free [Al(H 2 O) 6 ] 3+ ion and the trinuclear complex, which has a high complexation rate, is higher in the Ferron assay than in the 27 Al qNMR technique. The concentrations of four Al species were directly determined by 27 Al qNMR, namely, free [Al(H 2 O) 6 ] 3+ , the trinuclear complex, Al(OH) 4 - , and tridecameric hydrolyzed Al, which has a Keggin structure. The concentration of the tridecamer rapidly increased until 100 min after NaOH addition, and showed a local maximum after 1 week. In addition, the concentration of colloidal Al hydroxide, which cannot be detected by NMR spectroscopy, was determined by numerical analysis. This species was generated in the initial stage of reaction, and then the tridecamer formed very slowly.

  16. Conformational analysis of amide extractants by NMR in organic phase

    International Nuclear Information System (INIS)

    Berthon, C.

    1993-08-01

    This study deals with nuclear fuel reprocessing. We have essentially used NMR spectroscopy. We want to understand which kind of conformational parameters control selectivity and efficiency of amide extractant. The symmetric monoamides used are DOBA (C 3 H 7 CON (CH 2 CH(C 2 H 5 ) C 4 H 9 ) 2 ), DOiBA ((CH 3 ) 2 CCHON (CH 2 CH(C 2 H 5 )C 4 H 9 ) 2 ) and DOTA ((CH 3 ) 3 CCH 2 CON(CH 2 CH(C 2 H 5 )C 4 H 9 ) 2 ). Each gives two quasi equivalent conformers (cis and trans) in organic phases. The selected malonamide DMDBTDMA ((C 4 H 9 (CH 3 )NCO) 2 CHC 14 H 29 ) has four conformers because of its twice disymmetric amide functions. Weak interactions between monoamides which yield to dimer formation. The malonamide also gives dimers but forms aggregates too. Nitric acid extraction is due to the competitive formation of six species L, L 2 , L 2 (HNO 3 ), L(HNO 3 ), L(HNO 3 ) 2 , L(HNO 3 ) 3 (L: monoamide). Complexation between lanthanides (III) and monoamides yields to the stoichiometries L 3 Ln(NO 3 ) 3 and L 2 Ln(NO 3 ) 3 . Their ratio depend of steric hindrance on the carbonyl and the metal ionic radius. The same thing is observed of Pu 4+ and Th 4+ extraction in non acidic media. L 2 An(NO 3 ) 4 is the main stoichiometric except for the Th 4+ - DOBA system where the species (DOBA) 3 Th(NO 3 ) 4 appear. Exchange rates between the ligand and the complex are pointed out. The monoamide conformations obtained with lanthanide and plutonium nitrate can explain the difference in extracting power of this molecule between An 4+ and Ln 3+ . (author). 162 refs., 87 figs., 44 tabs., 7 annexes

  17. MQ NMR and SPME analysis of nonlinearity in the degradation of a filled silicone elastomer

    Energy Technology Data Exchange (ETDEWEB)

    Chinn, S C; Alviso, C T; Berman, E S; Harvey, C A; Maxwell, R S; Wilson, T S; Cohenour, R; Saalwachter, K; Chasse, W

    2008-10-10

    Radiation induced degradation of polymeric materials occurs via numerous, simultaneous, competing chemical reactions. Though degradation is typically found to be linear in adsorbed dose, some silicone materials exhibit non-linear dose dependence due to dose dependent dominant degradation pathways. We have characterized the effects of radiative and thermal degradation on a model filled-PDMS system, Sylgard 184 (commonly used as an electronic encapsulant and in biomedical applications), using traditional mechanical testing, NMR spectroscopy, and sample headspace analysis using Solid Phase Micro-Extraction (SPME) followed by Gas Chromatography/Mass Spectrometry (GC/MS). The mechanical data and {sup 1}H spin-echo NMR indicated that radiation exposure leads to predominantly crosslinking over the cumulative dose range studies (0 to 250 kGray) with a rate roughly linear with dose. {sup 1}H Multiple Quantum NMR detected a bimodal distribution in the network structure, as expected by the proposed structure of Sylgard 184. The MQ-NMR further indicated that the radiation induced structural changes were not linear in adsorbed dose and competing chain scission mechanisms contribute more largely to the overall degradation process in the range of 50 -100 kGray (though crosslinking still dominates). The SPME-GC/MS data were analyzed using Principal Component Analysis (PCA), which identified subtle changes in the distributions of degradation products (the cyclic siloxanes and other components of the material) as a function of age that provide insight into the dominant degradation pathways at low and high adsorbed dose.

  18. Phenyl galactopyranosides – {sup 13}C CPMAS NMR and conformational analysis using genetic algorithm

    Energy Technology Data Exchange (ETDEWEB)

    Wałejko, Piotr, E-mail: pwalejko@uwb.edu.pl [University of Bialystok, Institute of Chemistry, Pilsudskiego 11/4, 15-443 Bialystok (Poland); Paradowska, Katarzyna, E-mail: katarzyna.paradowska@wum.edu.pl [Medical University of Warsaw, Faculty of Pharmacy, Department of Physical Chemistry, Banacha 1, 02-097 Warsaw (Poland); Bukowicki, Jarosław [Medical University of Warsaw, Faculty of Pharmacy, Department of Physical Chemistry, Banacha 1, 02-097 Warsaw (Poland); Witkowski, Stanisław [University of Bialystok, Institute of Chemistry, Pilsudskiego 11/4, 15-443 Bialystok (Poland); Wawer, Iwona [Medical University of Warsaw, Faculty of Pharmacy, Department of Physical Chemistry, Banacha 1, 02-097 Warsaw (Poland)

    2015-08-18

    Highlights: • The structures of phenyl galactosides were studied by {sup 13}C CPMAS NMR. • The GAAGS method was used in conformational analysis of phenyl galactosides. • The rotation of the aglycone was investigated. • {sup 13}C CPMAS NMR supported by GIAO DFT calculations was used as a verification method. - Abstract: Structural analyses of four compounds (phenyl 2,3,4,6-tetra-O-acetyl-β-D-galactopyranoside (1), phenyl β-D-galactopyranoside (2), phenyl 2,3,4,6-tetra-O-acetyl-α-D-galactopyranoside (3) and phenyl α-D-galactopyranoside (4)) have been performed using solid-state {sup 13}C MAS NMR spectroscopy and theoretical methods. Conformational analysis involved grid search and genetic algorithm (GAAGS). Low-energy conformers found by GAAGS were further optimized by DFT and chemical shifts were calculated using GIAO/DFT approach. {sup 13}C CPMAS NMR chemical shift of carbon C2 is indicative of the glycoside torsional angle. Separated or merged resonances of C2 and C6 suggest free rotation of phenyl ring in the solid phase.

  19. Quantitative Analysis of Chemically Modified Starches by 1H-NMR Spectroscopy

    NARCIS (Netherlands)

    Graaf, R.A. de; Lammers, G.; Janssen, L.P.B.M.; Beenackers, A.A.C.M.

    1995-01-01

    A quantitative 1H-NMR method for the determination of the Molar Substitution (MS) of acetylated and hydroxypropylated starches was developed and tested for MS ranging from 0.09 to 0.5. Results were checked using the Johnson method and a titration method for hydroxypropylated and acetylated starch,

  20. Quantitative analysis of chemically modified starches by H-1-NMR spectroscopy

    NARCIS (Netherlands)

    de Graaf, R.A.; Lammers, G; Janssen, L.P.B.M.; Beenackers, A.A C M

    1995-01-01

    A quantitative H-1-NMR method for the determination of the Molar Substitution (MS) of acetylated and hydroxypropylated starches was developed and tested for MS ranging from 0.09 to 0.5. Results were checked using the Johnson method and a titration method for hydroxypropylated and acetylated starch,

  1. PFG NMR and Bayesian analysis to characterise non-Newtonian fluids

    Science.gov (United States)

    Blythe, Thomas W.; Sederman, Andrew J.; Stitt, E. Hugh; York, Andrew P. E.; Gladden, Lynn F.

    2017-01-01

    Many industrial flow processes are sensitive to changes in the rheological behaviour of process fluids, and there therefore exists a need for methods that provide online, or inline, rheological characterisation necessary for process control and optimisation over timescales of minutes or less. Nuclear magnetic resonance (NMR) offers a non-invasive technique for this application, without limitation on optical opacity. We present a Bayesian analysis approach using pulsed field gradient (PFG) NMR to enable estimation of the rheological parameters of Herschel-Bulkley fluids in a pipe flow geometry, characterised by a flow behaviour index n , yield stress τ0 , and consistency factor k , by analysis of the signal in q -space. This approach eliminates the need for velocity image acquisition and expensive gradient hardware. We investigate the robustness of the proposed Bayesian NMR approach to noisy data and reduced sampling using simulated NMR data and show that even with a signal-to-noise ratio (SNR) of 100, only 16 points are required to be sampled to provide rheological parameters accurate to within 2% of the ground truth. Experimental validation is provided through an experimental case study on Carbopol 940 solutions (model Herschel-Bulkley fluids) using PFG NMR at a 1H resonance frequency of 85.2 MHz; for SNR > 1000, only 8 points are required to be sampled. This corresponds to a total acquisition time of probably due to shear history-dependent behaviour and the different geometries used. This behaviour highlights the need for online, or inline, rheological characterisation in industrial process applications.

  2. Current role and future perspectives of multivariate (chemometric) methods in NMR spectroscopic analysis of pharmaceutical products.

    Science.gov (United States)

    Monakhova, Yulia B; Holzgrabe, Ulrike; Diehl, Bernd W K

    2018-01-05

    Nuclear magnetic resonance (NMR) is a fast and accurate analytical method. Associated with chemometrics, it gradually becomes more important tool for the pharmaceutical industry. In this review studies dealing with the applications of multivariate analysis to NMR spectroscopic profiles were grouped and discussed according to the analytical problem solved. The following topics were covered: authenticity of medicines according to variety, seasonal and geographical differences of herbal plants; quantitative prediction of pharmacologically relevant parameters; production and batches approval; investigation of drug structure modifications; site-specific natural isotope fractionation (SNIF-NMR) fingerprinting for origin and manufacturer tracking and others. Special focus was put on the heparin authenticity by using 1D and 2D NMR measurements. Finally, further research directions have been outlined. Our review has shown that chemometrics plays an important role for the quality control and authenticity of pharmaceutical products and its role will definitely increase in the future. The discussed approaches are recommended to be implemented during development and production process of pharmaceuticals or in quality control laboratories. Copyright © 2017 Elsevier B.V. All rights reserved.

  3. ¹H NMR and Multivariate Analysis for Geographic Characterization of Commercial Extra Virgin Olive Oil: A Possible Correlation with Climate Data.

    Science.gov (United States)

    Rongai, Domenico; Sabatini, Nadia; Del Coco, Laura; Perri, Enzo; Del Re, Paolo; Simone, Nicola; Marchegiani, Donato; Fanizzi, Francesco Paolo

    2017-11-07

    ¹H Nuclear Magnetic Resonance (NMR) spectroscopy coupled with multivariate analysis has been applied in order to investigate metabolomic profiles of more than 200 extravirgin olive oils (EVOOs) collected in a period of over four years (2009-2012) from different geographic areas. In particular, commercially blended EVOO samples originating from different Italian regions (Tuscany, Sicily and Apulia), as well as European (Spain and Portugal) and non-European (Tunisia, Turkey, Chile and Australia) countries. Multivariate statistical analysis (Principal Component Analisys (PCA) and Orthogonal Partial Least Squares Discriminant Analysis (OPLS-DA)) applied on the NMR data revealed the existence of marked differences between Italian (in particular from Tuscany, Sicily and Apulia regions) and foreign (in particular Tunisian) EVOO samples. A possible correlation with available climate data has been also investigated. These results aim to develop a powerful NMR-based tool able to protect Italian olive oil productions.

  4. 1H NMR and Multivariate Analysis for Geographic Characterization of Commercial Extra Virgin Olive Oil: A Possible Correlation with Climate Data

    Directory of Open Access Journals (Sweden)

    Domenico Rongai

    2017-11-01

    Full Text Available 1H Nuclear Magnetic Resonance (NMR spectroscopy coupled with multivariate analysis has been applied in order to investigate metabolomic profiles of more than 200 extravirgin olive oils (EVOOs collected in a period of over four years (2009–2012 from different geographic areas. In particular, commercially blended EVOO samples originating from different Italian regions (Tuscany, Sicily and Apulia, as well as European (Spain and Portugal and non-European (Tunisia, Turkey, Chile and Australia countries. Multivariate statistical analysis (Principal Component Analisys (PCA and Orthogonal Partial Least Squares Discriminant Analysis (OPLS-DA applied on the NMR data revealed the existence of marked differences between Italian (in particular from Tuscany, Sicily and Apulia regions and foreign (in particular Tunisian EVOO samples. A possible correlation with available climate data has been also investigated. These results aim to develop a powerful NMR-based tool able to protect Italian olive oil productions.

  5. A Analysis of Molecular Dynamics in Water-Cellulose Systems by Pulsed NMR

    Science.gov (United States)

    Hale, Michael Edward

    1990-01-01

    This thesis presents important advances in the application of Nuclear Magnetic Resonance (NMR) in three different areas: experimental apparatus, data analysis techniques in heterogeneous systems, and understanding of the determinants of the water relaxation in water-cellulose systems. A microprocessor-based pulse programmer is described which can conveniently produce virtually any conceivable pulse sequence, is synchronized with the spectrometer rf source, and is suitable for external computer control and automated data acquisition. A special programming language was implemented for use in the pulse programmer to allow it to be controlled by simple strings of ASCII characters. The common use of models based on a distribution of correlation times to analyze NMR relaxation time data in heterogeneous systems has been critically examined. Serious difficulties of principle in such analyses have been found. An adaptive numerical integration strategy is necessary for accurate results. Nonlinear least squares analysis of the relaxation data requires the use of slower, but more stable techniques than those considered standard. A single fit requires a daunting amount of computing under these conditions. These numerical techniques lead to a unique set of parameters in cases where the error on the data is very small. However, when data with reasonable experimental errors are analyzed, the fitting routines become sensitive to the starting parameters. The usefulness of a distribution of correlation times model for routine analysis of relaxation data in heterogeneous systems must be seriously questioned. NMR relaxation in three systems is analyzed: (a) dry Sigmacell cellulose and samples hydrated with H _2O; (b) deuterated Sigmacell 50 hydrated with D_2O; and (c) microfibrillated cellulose with high water content (less than 3% by weight cellulose). Two similar models are considered to explain T_1 and T_2 data. Both adequately describe the data. The first is an anisotropic motion

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

    Science.gov (United States)

    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…

  7. The application of NMR-based milk metabolite analysis in milk authenticity identification.

    Science.gov (United States)

    Li, Qiangqiang; Yu, Zunbo; Zhu, Dan; Meng, Xianghe; Pang, Xiumei; Liu, Yue; Frew, Russell; Chen, He; Chen, Gang

    2017-07-01

    Milk is an important food component in the human diet and is a target for fraud, including many unsafe practices. For example, the unscrupulous adulteration of soymilk into bovine and goat milk or of bovine milk into goat milk in order to gain profit without declaration is a health risk, as the adulterant source and sanitary history are unknown. A robust and fit-for-purpose technique is required to enforce market surveillance and hence protect consumer health. Nuclear magnetic resonance (NMR) is a powerful technique for characterization of food products based on measuring the profile of metabolites. In this study, 1D NMR in conjunction with multivariate chemometrics as well as 2D NMR was applied to differentiate milk types and to identify milk adulteration. Ten metabolites were found which differed among milk types, hence providing characteristic markers for identifying the milk. These metabolites were used to establish mathematical models for milk type differentiation. The limit of quantification (LOQ) of adulteration was 2% (v/v) for soymilk in bovine milk, 2% (v/v) for soymilk in goat milk and 5% (v/v) for bovine milk in goat milk, with relative standard deviation (RSD) less than 10%, which can meet the needs of daily inspection. The NMR method described here is effective for milk authenticity identification, and the study demonstrates that the NMR-based milk metabolite analysis approach provides a means of detecting adulteration at expected levels and can be used for dairy quality monitoring. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

  8. Analysis of monoglycerides, diglycerides, sterols, and free fatty acids in coconut (Cocos nucifera L.) oil by 31P NMR spectroscopy.

    Science.gov (United States)

    Dayrit, Fabian M; Buenafe, Olivia Erin M; Chainani, Edward T; de Vera, Ian Mitchelle S

    2008-07-23

    Phosphorus-31 nuclear magnetic resonance spectroscopy ( (31)P NMR) was used to differentiate virgin coconut oil (VCO) from refined, bleached, deodorized coconut oil (RCO). Monoglycerides (MGs), diglycerides (DGs), sterols, and free fatty acids (FFAs) in VCO and RCO were converted into dioxaphospholane derivatives and analyzed by (31)P NMR. On the average, 1-MG was found to be higher in VCO (0.027%) than RCO (0.019%). 2-MG was not detected in any of the samples down to a detection limit of 0.014%. On the average, total DGs were lower in VCO (1.55%) than RCO (4.10%). When plotted in terms of the ratio [1,2-DG/total DGs] versus total DGs, VCO and RCO samples grouped separately. Total sterols were higher in VCO (0.096%) compared with RCO (0.032%), and the FFA content was 8 times higher in VCO than RCO (0.127% vs 0.015%). FFA determination by (31)P NMR and titration gave comparable results. Principal components analysis shows that the 1,2-DG, 1,3-DG, and FFAs are the most important parameters for differentiating VCO from RCO.

  9. Chemical tagging of chlorinated phenols for their facile detection and analysis by NMR spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Valdez, Carlos A. [Lawrence Livermore National Laboratory (LLNL), Livermore, CA (United States); Leif, Roald N. [Lawrence Livermore National Laboratory (LLNL), Livermore, CA (United States)

    2015-03-22

    A derivatization method that employs diethyl (bromodifluoromethyl) phosphonate (DBDFP) to efficiently tag the endocrine disruptor pentachlorophenol (PCP) and other chlorinated phenols (CPs) along with their reliable detection and analysis by NMR is presented. The method accomplishes the efficient alkylation of the hydroxyl group in CPs with the difluoromethyl (CF2H) moiety in extremely rapid fashion (5 min), at room temperature and in an environmentally benign manner. The approach proved successful in difluoromethylating a panel of 18 chlorinated phenols, yielding derivatives that displayed unique 1H, 19F NMR spectra allowing for the clear discrimination between isomerically related CPs. Due to its biphasic nature, the derivatization can be applied to both aqueous and organic mixtures where the analysis of CPs is required. Furthermore, the methodology demonstrates that PCP along with other CPs can be selectively derivatized in the presence of other various aliphatic alcohols, underscoring the superiority of the approach over other general derivatization methods that indiscriminately modify all analytes in a given sample. The present work demonstrates the first application of NMR on the qualitative analysis of these highly toxic and environmentally persistent species.

  10. Quantitative analysis of water heavy by NMR spectroscopy

    International Nuclear Information System (INIS)

    Gomez Gil, V.

    1975-01-01

    Nuclear Magnetic Resonance has been applied to a wide variety of quantitative problems. A typical example has been the determination of isotopic composition. In this paper two different analytical methods for the determination of water in deuterium oxide are described. The first one, employs acetonitril as an internal standard compound and in the second one calibration curve of signal integral curve versus amount of D 2 O is constructed. Both methods give results comparable to those of mass spectrometry of IR spectroscopy. (Author) 5 refs

  11. Compositional analysis of multi-element magnetic nanoparticles with a combined NMR and TEM approach

    Science.gov (United States)

    Gellesch, Markus; Hammerath, Franziska; Süß, Vicky; Haft, Marcel; Hampel, Silke; Wurmehl, Sabine; Büchner, Bernd

    2017-09-01

    The increasing interest in nanoscale materials goes hand in hand with the challenge to reliably characterize the chemical compositions and structural features of nanosized objects in order to relate those to their physical properties. Despite efforts, the analysis of the chemical composition of individual multi-element nanoparticles remains challenging—from the technical point of view as well as from the point of view of measurement statistics. Here, we demonstrate that zero-field solid-state nuclear magnetic resonance (NMR) complements local, single particle transmission electron microscopy (TEM) studies with information on a large assembly of chemically complex nanoparticles. The combination of both experimental techniques gives information on the local composition and structure and provides an excellent measurement statistic through the corresponding NMR ensemble measurement. This analytical approach is applicable to many kinds of magnetic materials and therefore may prove very versatile in the future research of particulate magnetic nanomaterials.

  12. Quality assessment of ginseng by (1)H NMR metabolite fingerprinting and profiling analysis.

    Science.gov (United States)

    Lee, Eun-Jeong; Shaykhutdinov, Rustem; Weljie, Aalim M; Vogel, Hans J; Facchini, Peter J; Park, Sang-Un; Kim, Yong-Kyoung; Yang, Tae-Jin

    2009-08-26

    Metabolite profiling and fingerprint analysis by (1)H NMR spectroscopy were used to identify potential biomarkers capable of distinguishing different ginseng species, varieties, and commercial products with the aim of establishing quality control code protocol based on biochemical phenotype. Principal component (PC) analyses of (1)H NMR spectra reliably discriminated between the various ginseng samples, demonstrating the potential utility of metabolomics in the natural health products industry. Four Asian ginseng varieties separated along the PC1 and PC2 axes, and four different Korean ginseng products were divided into two groups by PC1. A strong separation was also revealed between Asian ginseng (Panax ginseng) and American ginseng (Panax quinquefolius). Glutamine, arginine, sucrose, malate, and myo-inositol were the major metabolites in ginseng samples tested in this study. Combined metabolite fingerprinting and profiling suggested that several compounds including glucose, fumarate, and various amino acids could serve as biomarkers for quality assurance in ginseng.

  13. NMR metabolic analysis of samples using fuzzy K-means clustering.

    Science.gov (United States)

    Cuperlović-Culf, Miroslava; Belacel, Nabil; Culf, Adrian S; Chute, Ian C; Ouellette, Rodney J; Burton, Ian W; Karakach, Tobias K; Walter, John A

    2009-12-01

    The global analysis of metabolites can be used to define the phenotypes of cells, tissues or organisms. Classifying groups of samples based on their metabolic profile is one of the main topics of metabolomics research. Crisp clustering methods assign each feature to one cluster, thereby omitting information about the multiplicity of sample subtypes. Here, we present the application of fuzzy K-means clustering method for the classification of samples based on metabolomics 1D (1)H NMR fingerprints. The sample classification was performed on NMR spectra of cancer cell line extracts and of urine samples of type 2 diabetes patients and animal models. The cell line dataset included NMR spectra of lipophilic cell extracts for two normal and three cancer cell lines with cancer cell lines including two invasive and one non-invasive cancers. The second dataset included previously published NMR spectra of urine samples of human type 2 diabetics and healthy controls, mouse wild type and diabetes model and rat obese and lean phenotypes. The fuzzy K-means clustering method allowed more accurate sample classification in both datasets relative to the other tested methods including principal component analysis (PCA), hierarchical clustering (HCL) and K-means clustering. In the cell line samples, fuzzy clustering provided a clear separation of individual cell lines, groups of cancer and normal cell lines as well as non-invasive and invasive tumour cell lines. In the diabetes dataset, clear separation of healthy controls and diabetics in all three models was possible only by using the fuzzy clustering method.

  14. Quantitative analysis of deuterium using the isotopic effect on quaternary {sup 13}C NMR chemical shifts

    Energy Technology Data Exchange (ETDEWEB)

    Darwish, Tamim A., E-mail: tamim.darwish@ansto.gov.au [National Deuteration Facility, Australian Nuclear Science and Technology Organisation, Locked Bag 21, Kirrawee DC, NSW 2232 (Australia); Yepuri, Nageshwar Rao; Holden, Peter J. [National Deuteration Facility, Australian Nuclear Science and Technology Organisation, Locked Bag 21, Kirrawee DC, NSW 2232 (Australia); James, Michael [Australian Synchrotron, 800 Blackburn Road, Clayton, Victoria 3168 (Australia)

    2016-07-13

    Quantitative analysis of specifically deuterated compounds can be achieved by a number of conventional methods, such as mass spectroscopy, or by quantifying the residual {sup 1}H NMR signals compared to signals from internal standards. However, site specific quantification using these methods becomes challenging when dealing with non-specifically or randomly deuterated compounds that are produced by metal catalyzed hydrothermal reactions in D{sub 2}O, one of the most convenient deuteration methods. In this study, deuterium-induced NMR isotope shifts of quaternary {sup 13}C resonances neighboring deuterated sites have been utilized to quantify the degree of isotope labeling of molecular sites in non-specifically deuterated molecules. By probing {sup 13}C NMR signals while decoupling both proton and deuterium nuclei, it is possible to resolve {sup 13}C resonances of the different isotopologues based on the isotopic shifts and the degree of deuteration of the carbon atoms. We demonstrate that in different isotopologues, the same quaternary carbon, neighboring partially deuterated carbon atoms, are affected to an equal extent by relaxation. Decoupling both nuclei ({sup 1}H, {sup 2}H) resolves closely separated quaternary {sup 13}C signals of the different isotopologues, and allows their accurate integration and quantification under short relaxation delays (D1 = 1 s) and hence fast accumulative spectral acquisition. We have performed a number of approaches to quantify the deuterium content at different specific sites to demonstrate a convenient and generic analysis method for use in randomly deuterated molecules, or in cases of specifically deuterated molecules where back-exchange processes may take place during work up. - Graphical abstract: The relative intensities of quaternary {sup 13}C {"1H,"2H} resonances are equal despite the different relaxation delays, allowing the relative abundance of the different deuterated isotopologues to be calculated using NMR fast

  15. An integrated analysis for determining the geographical origin of medicinal herbs using ICP-AES/ICP-MS and (1)H NMR analysis.

    Science.gov (United States)

    Kwon, Yong-Kook; Bong, Yeon-Sik; Lee, Kwang-Sik; Hwang, Geum-Sook

    2014-10-15

    ICP-MS and (1)H NMR are commonly used to determine the geographical origin of food and crops. In this study, data from multielemental analysis performed by ICP-AES/ICP-MS and metabolomic data obtained from (1)H NMR were integrated to improve the reliability of determining the geographical origin of medicinal herbs. Astragalus membranaceus and Paeonia albiflora with different origins in Korea and China were analysed by (1)H NMR and ICP-AES/ICP-MS, and an integrated multivariate analysis was performed to characterise the differences between their origins. Four classification methods were applied: linear discriminant analysis (LDA), k-nearest neighbour classification (KNN), support vector machines (SVM), and partial least squares-discriminant analysis (PLS-DA). Results were compared using leave-one-out cross-validation and external validation. The integration of multielemental and metabolomic data was more suitable for determining geographical origin than the use of each individual data set alone. The integration of the two analytical techniques allowed diverse environmental factors such as climate and geology, to be considered. Our study suggests that an appropriate integration of different types of analytical data is useful for determining the geographical origin of food and crops with a high degree of reliability. Copyright © 2014 Elsevier Ltd. All rights reserved.

  16. NMR analysis of aldehydes in Sicilian extra-virgin olive oils by DPFGSE techniques

    Directory of Open Access Journals (Sweden)

    Enrico Rotondo

    2011-03-01

    Full Text Available The DPFGSE NMR sequences open new perspectives in the volatile compounds analysis of food matrices. Many fresh extra-virgin Sicilian olive oils, analyzed by this technique, show two main resonances in the aldehydic spectral region (9–10 ppm, at 9.18 and 9.58 ppm. The former was never reported so far, the latter was sometime highlighted as a minor aldehydic component signal of spectra showing stronger resonances at 9.45 and 9.70 ppm. Thermal treatment at 220°C of extra virgin olive oil samples lead to the complete transformation of the resonances at 9.18 and 9.58 ppm into those at 9.45 and 9.70 ppm in 50 minutes. Analogous transformation takes place place in CDCl3 at rt in several weeks. These results suggest the transformation of relatively unstable compounds into thermodynamically more stable products whose resonances are commonly reported in the literature. Even though these chemical changes involve minimal amount of product, they are of crucial importance to define: i organoleptic extra virgin olive oil properties; ii fraudulent chemical or thermal treatment detection; iii extra virgin oil ageing.

  17. Experimental and NMR theoretical methodology applied to geometric analysis of the bioactive clerodane trans-dehydrocrotonin

    Energy Technology Data Exchange (ETDEWEB)

    Soares, Breno Almeida; Firme, Caio Lima, E-mail: firme.caio@gmail.com, E-mail: caiofirme@quimica.ufrn.br [Universidade Federal do Rio Grande do Norte (UFRN), Natal, RN (Brazil). Instituto de Quimica; Maciel, Maria Aparecida Medeiros [Universidade Potiguar, Natal, RN (Brazil). Programa de Pos-graduacao em Biotecnologia; Kaiser, Carlos R. [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Instituto de Quimica; Schilling, Eduardo; Bortoluzzi, Adailton J. [Universidade Federal de Santa Catarina (UFSC), Florianopolis, SC (Brazil). Departamento de Quimica

    2014-04-15

    trans-Dehydrocrotonin (t-DCTN) a bioactive 19-nor-diterpenoid clerodane type isolated from Croton cajucara Benth, is one of the most investigated clerodane in the current literature. In this work, a new approach joining X-ray diffraction data, nuclear magnetic resonance (NMR) data and theoretical calculations was applied to the thorough characterization of t-DCTN. For that, the geometry of t-DCTN was reevaluated by X-ray diffraction as well as {sup 1}H and {sup 13}C NMR data, whose geometrical parameters where compared to those obtained from B3LYP/6-311G++(d,p) level of theory. From the evaluation of both calculated and experimental values of {sup 1}H and {sup 13}C NMR chemical shifts and spin-spin coupling constants, it was found very good correlations between theoretical and experimental magnetic properties of t-DCTN. Additionally, the delocalization indexes between hydrogen atoms correlated accurately with theoretical and experimental spin-spin coupling constants. An additional topological analysis from quantum theory of atoms in molecules (QTAIM) showed intramolecular interactions for t-DCTN. (author)

  18. Component separation in NMR imaging and multidimensional spectroscopy through global least-squares analysis, based on prior knowledge.

    Science.gov (United States)

    Stilbs, P

    1998-11-01

    Use of prior knowledge with regard to the number of components in an image or NMR data set makes possible a full analysis and separation of correlated sets of such data. It is demonstrated that a diffusional NMR microscopy image set can readily be separated into its components, with the extra benefit of a global least-squares fit over the whole image of the respective diffusional rates. As outlined, the computational approach (CORE processing) is also applicable to various multidimensional NMR data sets and is suggested as a potentially powerful tool in functional MRI. Copyright 1998 Academic Press.

  19. A structural homologue of colipase in black mamba venom revealed by NMR floating disulphide bridge analysis.

    Science.gov (United States)

    Boisbouvier, J; Albrand, J P; Blackledge, M; Jaquinod, M; Schweitz, H; Lazdunski, M; Marion, D

    1998-01-01

    The solution structure of mamba intestinal toxin 1 (MIT1), isolated from Dendroaspis polylepis polylepis venom, has been determined. This molecule is a cysteine-rich polypeptide exhibiting no recognised family membership. Resistance to MIT1 to classical specific endoproteases produced contradictory NMR and biochemical information concerning disulphide-bridge topology. We have used distance restraints allowing ambiguous partners between S atoms in combination with NMR-derived structural information, to correctly determine the disulphide-bridge topology. The resultant solution structure of MIT1, determined to a resolution of 0.5 A, reveals an unexpectedly similar global fold with respect to colipase, a protein involved in fatty acid digestion. Colipase exhibits an analogous resistance to endoprotease activity, indicating for the first time the possible topological origins of this biochemical property. The biochemical and structural homology permitted us to propose a mechanically related digestive function for MIT1 and provides novel information concerning snake venom protein evolution. Copyright 1998 Academic Press.

  20. Spectroscopic data of Labdane Diterpenes: a theoretical analysis via NMR and DFT

    International Nuclear Information System (INIS)

    Souza, Fabrine S. de; Silva, Silvana de O.; Alves, Cláudio N.; Guilhon, Giselle M.S.P.

    2015-01-01

    Labdane diterpenes exhibit important bioactivities such as cardiovascular effects in rats as well as effects in the treatment of autoimmune diseases and Alzheimer syndrome. Recently, the labdane diterpenes ent-13-epi-manoil oxide, ribenone and ribenol were isolated from Croton palanostigma. The computational method DFT/B3LYP/cc-pVDZ was used to optimize the structures of these diterpenes and to calculate infrared data. Chemical shifts (δ H and δ C ) of the minimum energy structures (local minimum) were calculated and compared with the experimental data. Comparison of the NMR data by simple linear regression (SLR) showed satisfactory statistical results with a correlation coefficient (R 2 ) and predictive ability (Q 2 ) of over 98%. The predicted NMR data were used to confirm the δ H values that have not been published. (author)

  1. Mesh size analysis of cellulose nanofibril hydrogels using solute exclusion and PFG-NMR spectroscopy.

    Science.gov (United States)

    Jowkarderis, Leila; van de Ven, Theo G M

    2015-12-21

    The pore structure of TEMPO-mediated oxidized CNF hydrogels, chemically cross-linked with water-soluble diamines, is studied. A solute exclusion method and pulsed-field-gradient NMR are used to estimate the mesh size distribution in the gel network in its hydrated state. Dextran fractions with the nominal molecular weights in the range of 10-2000 kDa are used as probes. The results show a nonuniform network structure, consisting of a group of large openings that contain ∼50% of water, and regions with a more compact structure and smaller mesh units that restrict the diffusivity of the dextran molecules. A biexponential model is proposed for the NMR echo amplitude decay due to the probe diffusion into the gel network. A typical single exponential model does not fit the experimental data when the probe molecular size is comparable to the network mesh size. The results obtained with NMR, using the proposed biexponential model, are in very good agreement with those determined with solute exclusion. Precise mesh size estimation with solute exclusion using pore models is subject to restrictions, and vary with the assumed pore geometry. The average mesh size obtained using a spherical pore model, ∼35 nm, in the compact regions of the hydrogel, is in good agreement with the theoretical value in a network of rodlike particles. Neglecting the wall effects leads to underestimation of the mesh size with both techniques.

  2. Recommendations of the wwPDB NMR Validation Task Force

    Science.gov (United States)

    Montelione, Gaetano T.; Nilges, Michael; Bax, Ad; Güntert, Peter; Herrmann, Torsten; Richardson, Jane S.; Schwieters, Charles; Vranken, Wim F.; Vuister, Geerten W.; Wishart, David S.; Berman, Helen M.; Kleywegt, Gerard J.; Markley, John L.

    2013-01-01

    As methods for analysis of biomolecular structure and dynamics using nuclear magnetic resonance spectroscopy (NMR) continue to advance, the resulting 3D structures, chemical shifts, and other NMR data are broadly impacting biology, chemistry, and medicine. Structure model assessment is a critical area of NMR methods development, and is an essential component of the process of making these structures accessible and useful to the wider scientific community. For these reasons, the Worldwide Protein Data Bank (wwPDB) has convened an NMR Validation Task Force (NMR-VTF) to work with the wwPDB partners in developing metrics and policies for biomolecular NMR data harvesting, structure representation, and structure quality assessment. This paper summarizes the recommendations of the NMR-VTF, and lays the groundwork for future work in developing standards and metrics for biomolecular NMR structure quality assessment. PMID:24010715

  3. Chiral analysis of chloro intermediates of methylamphetamine by one-dimensional and multidimentional NMR and GC/MS.

    Science.gov (United States)

    Płotka, Justyna M; Morrison, Calum; Adam, David; Biziuk, Marek

    2012-07-03

    Impurity profiling and classification of abused drugs using chiral analytical techniques is of particular interest and importance because of the additional information obtained from this approach. When these methods are applied to the synthesis of illicitly used substances, they can supply valuable information about the conditions/chemicals used in the synthesis. We have applied GC and NMR methods to the study of intermediates found in methylamphetamine manufacture with the aim of linking the intermediates to the ephedrine/pseudoephedrine starting materials. Therefore, determination of the stereochemical makeup within samples of forensic interest is important giving further specific information to the analyst. This study investigates the stereochemical course of the Emde synthesis of methylamphetamine with particular focus on intermediate formation via the chlorination of ephedrine and pseudoephedrine enantiomers. The configurations of these chloro-phenethylamines were determined by 1D and 2D NMR analysis, and thereafter, the GC/MS analysis was carried out. We have shown here that chlorination of the ephedrine/pseudoephedrine compounds occurs via inversion (S(N)2) and retention (S(N)i) of configuration around the α carbon and mixture of diastereoisomers (chloroephedrine and chloropseudoephedrine) were formed, with the ratio of the resulting compounds dependent on the precursors used. The preparation and analytical properties of these intermediate standards provide data for laboratories interested in the stereochemical analysis of methylamphetamine intermediates such as forensic/law enforcement, and illustrate the value of using a combination of analytical methodology.

  4. Characterization of solid polymer dispersions of active pharmaceutical ingredients by 19F MAS NMR and factor analysis

    Czech Academy of Sciences Publication Activity Database

    Urbanová, Martina; Brus, Jiří; Šeděnková, Ivana; Policianová, Olivia; Kobera, Libor

    2013-01-01

    Roč. 100, 1 January (2013), s. 59-66 ISSN 1386-1425 R&D Projects: GA ČR GPP106/11/P426; GA MŠk 2B08021 Institutional research plan: CEZ:AV0Z40500505 Institutional support: RVO:61389013 Keywords : solid-state NMR * factor analysis * 19F MAS NMR Subject RIV: FR - Pharmacology ; Medidal Chemistry Impact factor: 2.129, year: 2013

  5. Theoretical NMR and conformational analysis of solvated oximes for organophosphates-inhibited acetylcholinesterase reactivation

    Science.gov (United States)

    da Silva, Jorge Alberto Valle; Modesto-Costa, Lucas; de Koning, Martijn C.; Borges, Itamar; França, Tanos Celmar Costa

    2018-01-01

    In this work, quaternary and non-quaternary oximes designed to bind at the peripheral site of acetylcholinesterase previously inhibited by organophosphates were investigated theoretically. Some of those oximes have a large number of degrees of freedom, thus requiring an accurate method to obtain molecular geometries. For this reason, the density functional theory (DFT) was employed to refine their molecular geometries after conformational analysis and to compare their 1H and 13C nuclear magnetic resonance (NMR) theoretical signals in gas-phase and in solvent. A good agreement with experimental data was achieved and the same theoretical approach was employed to obtain the geometries in water environment for further studies.

  6. Tannin structural elucidation and quantitative ³¹P NMR analysis. 2. Hydrolyzable tannins and proanthocyanidins.

    Science.gov (United States)

    Melone, Federica; Saladino, Raffaele; Lange, Heiko; Crestini, Claudia

    2013-10-02

    An unprecedented analytical method that allows simultaneous structural and quantitative characterization of all functional groups present in tannins is reported. In situ labeling of all labile H groups (aliphatic and phenolic hydroxyls and carboxylic acids) with a phosphorus-containing reagent (Cl-TMDP) followed by quantitative ³¹P NMR acquisition constitutes a novel fast and reliable analytical tool for the analysis of tannins and proanthocyanidins with significant implications for the fields of food and feed analyses, tannery, and the development of natural polyphenolics containing products.

  7. A suite of Mathematica notebooks for the analysis of protein main chain 15N NMR relaxation data

    International Nuclear Information System (INIS)

    Spyracopoulos, Leo

    2006-01-01

    A suite of Mathematica notebooks has been designed to ease the analysis of protein main chain 15 N NMR relaxation data collected at a single magnetic field strength. Individual notebooks were developed to perform the following tasks: nonlinear fitting of 15 N-T 1 and -T 2 relaxation decays to a two parameter exponential decay, calculation of the principal components of the inertia tensor from protein structural coordinates, nonlinear optimization of the principal components and orientation of the axially symmetric rotational diffusion tensor, model-free analysis of 15 N-T 1 , -T 2 , and { 1 H}- 15 N NOE data, and reduced spectral density analysis of the relaxation data. The principle features of the notebooks include use of a minimal number of input files, integrated notebook data management, ease of use, cross-platform compatibility, automatic visualization of results and generation of high-quality graphics, and output of analyses in text format

  8. High resolution magic angle spinning NMR applied to the analysis of organic compounds bound to solid supports.

    Science.gov (United States)

    Espinosa, Juan F

    2011-01-01

    In situ structural characterization of organic compounds attached to solid supports can be achieved by high-resolution magic angle spinning NMR (HRMAS NMR), a technique that provides solution-like spectra for resin-bound molecules. This review outlines the principles of the technique, the influence of the solid support on data quality, and NMR experiments that are useful for obtaining valuable information. The review describes, with multiple examples mainly from the last 7 years, how HRMAS NMR has been applied to monitor solid-phase reactions, elucidate reaction products and quantify compound loading on a solid support. Other applications, such as conformational analysis of immobilized compounds and investigation of molecular interactions with compounds in solution, are also discussed.

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

    Science.gov (United States)

    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.

  10. A multianalytical approach for determining the geographical origin of ginseng using strontium isotopes, multielements, and 1H NMR analysis.

    Science.gov (United States)

    Lee, A-Reum; Gautam, Mukesh; Kim, Jahan; Shin, Woo-Jin; Choi, Man-Sik; Bong, Yeon-Sik; Hwang, Geum-Sook; Lee, Kwang-Sik

    2011-08-24

    Asian ginseng (Panax ginseng C.A. Meyer) is widely used as an Oriental medicine in the East Asian regions, particularly Korea and China. In the study, the strontium isotope ratios ((87)Sr/(86)Sr), multielements, and metabolite profiles of 35 ginseng samples collected from Korea and China were examined in an attempt to develop a method to distinguish the origin of ginsengs from the two countries. A multivariate statistical approach was performed to analyze the multielements and the (1)H nuclear magnetic resonance (NMR) data. Results of a t-test for Mg, Fe, Al, and Sc showed significant variation between Korean and Chinese ginsengs, indicating potential tracers for discriminating them. Discriminating between the ginsengs from the two countries was generally successful when both the (87)Sr/(86)Sr ratios and rare earth element (REE) contents were used together. Moreover, principal component analysis (PCA) derived from the (1)H NMR data revealed a significant separation between the ginsengs originating from the two countries. The major metabolites responsible for differentiation were sugars such as glucose, xylose, and sucrose. The results suggest that this multiplatform approach offers a comprehensive method to distinguish the origin of ginsengs.

  11. The inclusion complex of rosmarinic acid into beta-cyclodextrin: A thermodynamic and structural analysis by NMR and capillary electrophoresis.

    Science.gov (United States)

    Aksamija, Amra; Polidori, Ange; Plasson, Raphaël; Dangles, Olivier; Tomao, Valérie

    2016-10-01

    This work focuses on the characterization of the rosmarinic acid (RA)-β-cyclodextrin (CD) complex in aqueous solution by (1)H NMR (1D- and 2D-ROESY), completed with studies by capillary electrophoresis (CE). From the (1)H NMR data, the stoichiometry of the complex was determined by a Job's plot and the binding constant was estimated from a linear regression (Scott's method). At pH 2.9, the results showed that RA binds CD with a 1:1 stoichiometry and a binding constant Kb of 445 (±53) M(-1) or 465 (±81) M(-1) depending on the CD protons (H-5 or H-3) selected for the evaluation. The Kb value was also calculated from the CD-induced chemical shifts of each RA proton in order to collect information on the structure of the complex. The pH dependence of Kb revealed that the RA carboxylic form displays the highest affinity for CD. An investigation by capillary electrophoresis fully confirmed these results. 2D ROESY analysis provided detailed structural information on the complex and showed a strong correlation between H-3 and H-5 of CD and most RA protons. In conclusion, RA, an efficient phenolic antioxidant from rosemary with a marketing authorization, spontaneously forms a relatively stable inclusion complex with CD in water. Copyright © 2016 Elsevier Ltd. All rights reserved.

  12. Discrimination of cardiac subcellular creatine kinase fluxes by NMR spectroscopy: a new method of analysis.

    Science.gov (United States)

    Joubert, F; Hoerter, J A; Mazet, J L

    2001-12-01

    A challenge in the understanding of creatine kinase (CK) fluxes reflected by NMR magnetization transfer in the perfused rat heart is the choice of a kinetic model of analysis. The complexity of the energetic pathways, due to the presence of adenosine triphosphate (ATP)-inorganic phosphate (Pi) exchange, of metabolite compartmentation and of subcellular localization of CK isozymes cannot be resolve from the sole information obtained from a single NMR protocol. To analyze multicompartment exchanges, we propose a new strategy based on the simultaneous analysis of four inversion transfer protocols. The time course of ATP and Phosphocreatine (PCr) magnetizations computed from the McConnell equations were adjusted to their experimental value for exchange networks of increasing complexity (up to six metabolite pools). Exchange schemes were selected by the quality of their fit and their consistency with data from other sources: the size of mitochondrial pools and the ATP synthesis flux. The consideration of ATP-Pi exchange and of ATP compartmentation were insufficient to describe the data. The most appropriate exchange scheme in our normoxic heart involved the discrimination of three specific CK activities (cytosolic, mitochondrial, and close to ATPases). At the present level of heart contractility, the energy is transferred from mitochondria to myofibrils mainly by PCr.

  13. Point of care assessment of melanoma tumor signaling and metastatic burden from μNMR analysis of tumor fine needle aspirates and peripheral blood.

    Science.gov (United States)

    Gee, Michael S; Ghazani, Arezou A; Haq, Rizwan; Wargo, Jennifer A; Sebas, Matthew; Sullivan, Ryan J; Lee, Hakho; Weissleder, Ralph

    2017-04-01

    This study evaluates μNMR technology for molecular profiling of tumor fine needle aspirates and peripheral blood of melanoma patients. In vitro assessment of melanocyte (MART-1, HMB45) and MAP kinase signaling (pERK, pS6K) molecule expression was performed in human cell lines, while clinical validation was performed in an IRB-approved study of melanoma patients undergoing biopsy and blood sampling. Tumor FNA and blood specimens were compared with BRAF genetic analysis and cross-sectional imaging. μNMR in vitro analysis showed increased expression of melanocyte markers in melanoma cells as well as increased expression of phosphorylated MAP kinase targets in BRAF-mutant melanoma cells. Melanoma patient FNA samples showed increased pERK and pS6K levels in BRAF mutant compared with BRAF WT melanomas, with μNMR blood circulating tumor cell level increased with higher metastatic burden visible on imaging. These results indicate that μNMR technology provides minimally invasive point-of-care evaluation of tumor signaling and metastatic burden in melanoma patients. Copyright © 2016 Elsevier Inc. All rights reserved.

  14. a Combined Molecular Dynamics and NMR Spectroscopic Protocol for the Conformational Analysis of Oligosaccharides.

    Science.gov (United States)

    Varma, Vikram

    A combined experimental and theoretical protocol for the conformational analysis of oligosaccharides is presented. Three disaccharides, methyl alpha - scD-mannopyranosyl-(1 to 3)-alpha- scD-mannopyranoside, methyl beta- scD-galactopyranosyl-(1 to 4)-beta- scD-glucopyranoside, and propyl beta- scD-2-acetamido -2-deoxy glucopyranosyl-(1 to 3)- alpha- scL-rhamnopyranoside, are used to evaluate a protocol for conformational analysis that makes use of molecular dynamics calculations with the CHARMM force field. Dynamics trajectories computed in vacuo and in water are used to calculate time-averaged NMR parameters such as spin-lattice relaxation times (T_1 ), Nuclear Overhauser Enhancements (NOE), and heteronuclear spin-spin coupling constants (^3J _{rm CH}). The calculated NMR parameters are then compared to experimental values and used to evaluate the computational procedure. The energetically accessible conformations are effectively sampled by the simulations. The method has been extended to the conformational analysis of higher-order oligosaccharides corresponding to the cell-wall polysaccharide of the Streptococcus Group A, and the Shigella flexneri Y O-antigen. The Streptococcus Group A cell-wall polysaccharide is comprised of a backbone of rhamnopyranosyl units connected by alternating alpha- scL-(1 to 3) and alpha- scL -(1 to 2) linkages, to which are attached N-acetyl-beta- scD-glucosamine ( beta- scD-GlcpNAc) residues at the 3 positions of the rhamnose backbone.rm A&rm B^'qquad A^'& rm Bqquad Acr[{-alpha}{-}L{-}Rha {it p}{-}(1to2){-alpha }{-}L{-}Rha{it p} {-}(1to3){-alpha}{ -}L{-}Rha{it p}-(1to2) -alpha-L-Rha{it p}{-}(1 to3){-alpha}{-}L{- }Rha{it p}{-}cr&uparrow(1 to3)&uparrow(1to3)crbeta {-}D{-}&rm Glc{it p }NAcqquadbeta{-}D{-}& rm Glc{it p}NAccr&rm C ^'&rm C] A branched trisaccharide (A^' -(C)B), a tetrasaccharide (A^' -(C)B-A), a pentasaccharide (C^' -B^'-A ^'-(C)B), and two hexasaccharides (C^'-B^ '-A^' -(C)B-A) and (A-(C^')B ^'-A^' -(C)B), have been chosen

  15. Stable and rigid DTPA-like paramagnetic tags suitable for in vitro and in situ protein NMR analysis.

    Science.gov (United States)

    Chen, Jia-Liang; Zhao, Yu; Gong, Yan-Jun; Pan, Bin-Bin; Wang, Xiao; Su, Xun-Cheng

    2018-02-01

    Organic synthesis of a ligand with high binding affinities for paramagnetic lanthanide ions is an effective way of generating paramagnetic effects on proteins. These paramagnetic effects manifested in high-resolution NMR spectroscopy are valuable dynamic and structural restraints of proteins and protein-ligand complexes. A paramagnetic tag generally contains a metal chelating moiety and a reactive group for protein modification. Herein we report two new DTPA-like tags, 4PS-PyDTTA and 4PS-6M-PyDTTA that can be site-specifically attached to a protein with a stable thioether bond. Both protein-tag adducts form stable lanthanide complexes, of which the binding affinities and paramagnetic tensors are tunable with respect to the 6-methyl group in pyridine. Paramagnetic relaxation enhancement (PRE) effects of Gd(III) complex on protein-tag adducts were evaluated in comparison with pseudocontact shift (PCS), and the results indicated that both 4PS-PyDTTA and 4PS-6M-PyDTTA tags are rigid and present high-quality PREs that are crucially important in elucidation of the dynamics and interactions of proteins and protein-ligand complexes. We also show that these two tags are suitable for in-situ protein NMR analysis.

  16. Urine metabolite analysis as a function of deoxynivalenol exposure: an NMR-based metabolomics investigation.

    Science.gov (United States)

    Hopton, R P; Turner, E; Burley, V J; Turner, P C; Fisher, J

    2010-02-01

    Deoxynivalenol (DON) is a toxic fungal metabolite that frequently contaminates cereal crops including wheat, maize and barley. Despite knowledge of frequent exposure through diet, our understanding of the potential consequences of human exposure remains limited, in part due to the lack of validated exposure biomarkers. In this study, we interrogated the urinary metabolome using nuclear magnetic resonance (NMR) spectroscopy to compare individuals with known low and high DON exposure through consumption of their normal diet. Urine samples from 22 adults from the UK (seven males, 15 females; age range = 21-59 years) had previously determined urinary DON levels using an established liquid chromatography-mass spectrometry (LC-MS) assay. Urine samples were subsequently analysed using an NMR-based metabolomics approach coupled with multivariate statistical analysis. Metabolic profiling suggested that hippurate levels could be used to distinguish between groups with low (3.6 ng DON mg(-1) creatinine: 95% CI = 2.6, 5.0 ng mg(-1)) and high (11.1 ng mg(-1): 95% CI = 8.1, 15.5 ng mg(-1)) DON exposure, with the concentration of hippurate being significantly (1.5 times) higher for people with high DON exposure than for those with low DON exposure (p = 0.047). This, to our knowledge, is the first report of a metabolomics-derived biomarker of DON exposure in humans.

  17. Regioselective Hydration of an Alkene and Analysis of the Alcohol Product by Remote Access NMR: A Classroom Demonstration

    Science.gov (United States)

    Smith, Maureen E.; Johnson, Sara L.; Masterson, Douglas S.

    2013-01-01

    A two-part demonstration was conducted in our first-semester organic chemistry course designed to introduce students to the formation of alcohols, regioselective reactions, and analysis of organic products by NMR analysis. This demonstration utilized the oxymercuration-demercuration sequence to prepare an alcohol from an alkene in a Markovnikov…

  18. Extraction and [superscript 1]H NMR Analysis of Fats from Convenience Foods: A Laboratory Experiment for Organic Chemistry

    Science.gov (United States)

    Hartel, Aaron M.; Moore, Amy C.

    2014-01-01

    The extraction and analysis of fats from convenience foods (crackers, cookies, chips, candies) has been developed as an experiment for a second-year undergraduate organic chemistry laboratory course. Students gravimetrically determine the fat content per serving and then perform a [superscript 1]H NMR analysis of the recovered fat to determine the…

  19. CRAFT (complete reduction to amplitude frequency table)--robust and time-efficient Bayesian approach for quantitative mixture analysis by NMR.

    Science.gov (United States)

    Krishnamurthy, Krish

    2013-12-01

    The intrinsic quantitative nature of NMR is increasingly exploited in areas ranging from complex mixture analysis (as in metabolomics and reaction monitoring) to quality assurance/control. Complex NMR spectra are more common than not, and therefore, extraction of quantitative information generally involves significant prior knowledge and/or operator interaction to characterize resonances of interest. Moreover, in most NMR-based metabolomic experiments, the signals from metabolites are normally present as a mixture of overlapping resonances, making quantification difficult. Time-domain Bayesian approaches have been reported to be better than conventional frequency-domain analysis at identifying subtle changes in signal amplitude. We discuss an approach that exploits Bayesian analysis to achieve a complete reduction to amplitude frequency table (CRAFT) in an automated and time-efficient fashion - thus converting the time-domain FID to a frequency-amplitude table. CRAFT uses a two-step approach to FID analysis. First, the FID is digitally filtered and downsampled to several sub FIDs, and secondly, these sub FIDs are then modeled as sums of decaying sinusoids using the Bayesian approach. CRAFT tables can be used for further data mining of quantitative information using fingerprint chemical shifts of compounds of interest and/or statistical analysis of modulation of chemical quantity in a biological study (metabolomics) or process study (reaction monitoring) or quality assurance/control. The basic principles behind this approach as well as results to evaluate the effectiveness of this approach in mixture analysis are presented. Copyright © 2013 John Wiley & Sons, Ltd.

  20. Automation of peak-tracking analysis of stepwise perturbed NMR spectra.

    Science.gov (United States)

    Banelli, Tommaso; Vuano, Marco; Fogolari, Federico; Fusiello, Andrea; Esposito, Gennaro; Corazza, Alessandra

    2017-02-01

    We describe a new algorithmic approach able to automatically pick and track the NMR resonances of a large number of 2D NMR spectra acquired during a stepwise variation of a physical parameter. The method has been named Trace in Track (TINT), referring to the idea that a gaussian decomposition traces peaks within the tracks recognised through 3D mathematical morphology. It is capable of determining the evolution of the chemical shifts, intensity and linewidths of each tracked peak.The performances obtained in term of track reconstruction and correct assignment on realistic synthetic spectra were high above 90% when a noise level similar to that of experimental data were considered. TINT was applied successfully to several protein systems during a temperature ramp in isotope exchange experiments. A comparison with a state-of-the-art algorithm showed promising results for great numbers of spectra and low signal to noise ratios, when the graduality of the perturbation is appropriate. TINT can be applied to different kinds of high throughput chemical shift mapping experiments, with quasi-continuous variations, in which a quantitative automated recognition is crucial.

  1. Automation of peak-tracking analysis of stepwise perturbed NMR spectra

    Energy Technology Data Exchange (ETDEWEB)

    Banelli, Tommaso; Vuano, Marco [Università di Udine, Dipartimento di Area Medica (Italy); Fogolari, Federico [INBB (Italy); Fusiello, Andrea [Università di Udine, Dipartimento Politecnico di Ingegneria e Architettura (Italy); Esposito, Gennaro [INBB (Italy); Corazza, Alessandra, E-mail: alessandra.corazza@uniud.it [Università di Udine, Dipartimento di Area Medica (Italy)

    2017-02-15

    We describe a new algorithmic approach able to automatically pick and track the NMR resonances of a large number of 2D NMR spectra acquired during a stepwise variation of a physical parameter. The method has been named Trace in Track (TinT), referring to the idea that a gaussian decomposition traces peaks within the tracks recognised through 3D mathematical morphology. It is capable of determining the evolution of the chemical shifts, intensity and linewidths of each tracked peak.The performances obtained in term of track reconstruction and correct assignment on realistic synthetic spectra were high above 90% when a noise level similar to that of experimental data were considered. TinT was applied successfully to several protein systems during a temperature ramp in isotope exchange experiments. A comparison with a state-of-the-art algorithm showed promising results for great numbers of spectra and low signal to noise ratios, when the graduality of the perturbation is appropriate. TinT can be applied to different kinds of high throughput chemical shift mapping experiments, with quasi-continuous variations, in which a quantitative automated recognition is crucial.

  2. A Systematic Approach to Sensitivity Analysis of Fault Tolerant Systems in NMR Architecture

    Directory of Open Access Journals (Sweden)

    Kourosh Aslansefat

    2015-01-01

    Full Text Available A fault tree illustrates the ways through which a system fails. It states different ways in which combination of faulty components result in an undesired event in the system. Being used in phases such as designing and exploiting industrial systems, and the designers able to evaluate the dependability attributes such as reliability, MTTF and sensitivity. In addition, in the mentioned ability, the fault tree is a systematic method for finding systems bottlenecks and weakness point. In spite of its extensive use in evaluating the reliability of systems, fault tree is rarely used in calculating sensitivity. In the last decade, few researches has been conducted in this field, however these methods are not applicable to large scale systems and are not systematic. This paper provides a systematic method for evaluating system sensitivity through fault tree. Then, it introduces sensitivity of NMR architecture as one of the common structures of fault tolerance which is used for enhancing systems’ reliability, safety and availability in industry. This article presents a comprehensive and parameterized formula for NMR structure's sensitivity. The presented method can be a great help for designing and exploiting reliable systems engineers in systematic and instant calculation of sensitivity by means of fault tree.

  3. Three-dimensional absorbed dose determinations by N.M.R. analysis of phantom-dosemeters

    International Nuclear Information System (INIS)

    Gambarini, G.; Birattari, C.; Fumagalli, M.L.; Vai, A.; Monti, D.; Salvadori, P.; Facchielli, L.; Sichirollo, A.E.

    1996-01-01

    Magnetic resonance imaging of a tissue-equivalent phantom is a promising technique for three-dimensional determination of absorbed dose from ionizing radiation. A reliable method of determining the spatial distribution of absorbed dose is indispensable for the planning of treatment in the presently developed radiotherapy techniques aimed at obtaining high energy selectively delivered to cancerous tissues, with low dose delivered to the surrounding healthy tissue. Aqueous gels infused with the Fricke dosemeter (i.e. with a ferrous sulphate solution), as proposed in 1984 by Gore et al., have shown interesting characteristics and, in spite of some drawbacks that cause a few limitations to their utilisation, they have shown the feasibility of three-dimensional dose determinations by nuclear magnetic resonance (NMR) imaging. Fricke-infused agarose gels with various compositions have been analysed, considering the requirements of the new radiotherapy techniques, in particular Boron Neutron Capture Therapy (B.N.C.T.) and proton therapy. Special attention was paid to obtain good tissue equivalence for every radiation type of interest. In particular, the tissue equivalence for thermal neutrons, which is a not simple problem, has also been satisfactorily attained. The responses of gel-dosemeters having the various chosen compositions have been analysed, by mean of NMR instrumentation. Spectrophotometric measurements have also been performed, to verify the consistence of the results. (author)

  4. Combining NMR and small angle X-ray and neutron scattering in the structural analysis of a ternary protein-RNA complex

    International Nuclear Information System (INIS)

    Hennig, Janosch; Wang, Iren; Sonntag, Miriam; Gabel, Frank; Sattler, Michael

    2013-01-01

    Many processes in the regulation of gene expression and signaling involve the formation of protein complexes involving multi-domain proteins. Individual domains that mediate protein-protein and protein-nucleic acid interactions are typically connected by flexible linkers, which contribute to conformational dynamics and enable the formation of complexes with distinct binding partners. Solution techniques are therefore required for structural analysis and to characterize potential conformational dynamics. Nuclear magnetic resonance spectroscopy (NMR) provides such information but often only sparse data are obtained with increasing molecular weight of the complexes. It is therefore beneficial to combine NMR data with additional structural restraints from complementary solution techniques. Small angle X-ray/neutron scattering (SAXS/SANS) data can be efficiently combined with NMR-derived information, either for validation or by providing additional restraints for structural analysis. Here, we show that the combination of SAXS and SANS data can help to refine structural models obtained from data-driven docking using HADDOCK based on sparse NMR data. The approach is demonstrated with the ternary protein-protein-RNA complex involving two RNA recognition motif (RRM) domains of Sex-lethal, the N-terminal cold shock domain of Upstream-to-N-Ras, and msl-2 mRNA. Based on chemical shift perturbations we have mapped protein-protein and protein-RNA interfaces and complemented this NMR-derived information with SAXS data, as well as SANS measurements on subunit-selectively deuterated samples of the ternary complex. Our results show that, while the use of SAXS data is beneficial, the additional combination with contrast variation in SANS data resolves remaining ambiguities and improves the docking based on chemical shift perturbations of the ternary protein-RNA complex.

  5. Detection of counterfeit brand spirits using 1H NMR fingerprints in comparison to sensory analysis.

    Science.gov (United States)

    Kuballa, Thomas; Hausler, Thomas; Okaru, Alex O; Neufeld, Maria; Abuga, Kennedy O; Kibwage, Isaac O; Rehm, Jürgen; Luy, Burkhard; Walch, Stephan G; Lachenmeier, Dirk W

    2018-04-15

    Beverage fraud involving counterfeiting of brand spirits is an increasing problem not only due to deception of the consumer but also because it poses health risks e.g. from possible methanol admixture. Suspicious spirit samples from Russia and Kenya were analysed using 1 H nuclear magnetic resonance (NMR) spectroscopy in comparison to authentic products. Using linear regression analysis of spectral integral values, 4 counterfeited samples from Russia and 2 from Kenya were easily identifiable with R 2  counterfeited and authentic samples but the assessors were unable to correctly identify the counterfeited product in the majority of cases. An important conclusion is that consumers cannot assumed to be self-responsible when consuming counterfeit alcohol because there is no general ability to organoleptically detect counterfeit alcohol. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. Analysis of ZDDP Content and Thermal Decomposition in Motor Oils Using NAA and NMR

    Science.gov (United States)

    Ferguson, S.; Johnson, J.; Gonzales, D.; Hobbs, C.; Allen, C.; Williams, S.

    Zinc dialkyldithiophosphates (ZDDPs) are one of the most common anti-wear additives present in commercially-available motor oils. The ZDDP concentrations of motor oils are most commonly determined using inductively coupled plasma atomic emission spectroscopy (ICP-AES). As part of an undergraduate research project, we have determined the Zn concentrations of eight commercially-available motor oils and one oil additive using neutron activation analysis (NAA), which has potential for greater accuracy and less sensitivity to matrix effects as compared to ICP-AES. The 31P nuclear magnetic resonance (31P-NMR) spectra were also obtained for several oil additive samples which have been heated to various temperatures in order to study the thermal decomposition of ZDDPs.

  7. BnmrOffice: A Free Software for β-nmr Data Analysis

    Science.gov (United States)

    Saadaoui, Hassan

    A data-analysis framework with a graphical user interface (GUI) is developed to analyze β-nmr spectra in an automated and intuitive way. This program, named BnmrOffice is written in C++ and employs the QT libraries and tools for designing the GUI, and the CERN's Minuit optimization routines for minimization. The program runs under multiple platforms, and is available for free under the terms of the GNU GPL standards. The GUI is structured in tabs to search, plot and analyze data, along other functionalities. The user can tweak the minimization options; and fit multiple data files (or runs) using single or global fitting routines with pre-defined or new models. Currently, BnmrOffice reads TRIUMF's MUD data and ASCII files, and can be extended to other formats.

  8. Tannin structural elucidation and quantitative ³¹P NMR analysis. 1. Model compounds.

    Science.gov (United States)

    Melone, Federica; Saladino, Raffaele; Lange, Heiko; Crestini, Claudia

    2013-10-02

    Tannins and flavonoids are secondary metabolites of plants that display a wide array of biological activities. This peculiarity is related to the inhibition of extracellular enzymes that occurs through the complexation of peptides by tannins. Not only the nature of these interactions, but more fundamentally also the structure of these heterogeneous polyphenolic molecules are not completely clear. This first paper describes the development of a new analytical method for the structural characterization of tannins on the basis of tannin model compounds employing an in situ labeling of all labile H groups (aliphatic OH, phenolic OH, and carboxylic acids) with a phosphorus reagent. The ³¹P NMR analysis of ³¹P-labeled samples allowed the unprecedented quantitative and qualitative structural characterization of hydrolyzable tannins, proanthocyanidins, and catechin tannin model compounds, forming the foundations for the quantitative structural elucidation of a variety of actual tannin samples described in part 2 of this series.

  9. Analysis of Hydroperoxides in Solid Polyethylene by MAS (13)C NMR and EPR

    International Nuclear Information System (INIS)

    ASSINK, ROGER A.; CELINA, MATHIAS C.; DUNBAR, TIMOTHY D.; ALAM, TODD M.; CLOUGH, ROGER LEE; GILLEN, KENNETH T.

    1999-01-01

    13 C-enriched polyethylene was subjected to γ-irradiation in the presence of air at 25 and 80 C for total doses ranging from 71 to 355 kGy. Significant quantities of hydroperoxides were detected in the 25 C irradiated sample by 13 C magic angle spinning NMR spectroscopy. This method of detection was performed on the solid polymer and required no chemical derivatization or addition of solvent. The chemical stability and subsequent products of the hydroperoxide species were studied by annealing the irradiated samples in air at temperatures ranging from 22 to 110 C. A time-temperature superposition analysis provided an activation energy of 108 kJ/mol for the hydroperoxide decomposition process. The primary products of hydroperoxide decomposition were ketones and secondary alcohols with lesser amounts of acids and esters. EPR measurements suggest that the reactive hydroperoxide species reside in the amorphous phase of polyethylene, consistent with degradation occurring in the amorphous phase

  10. Reproducibility of NMR analysis of urine samples: impact of sample preparation, storage conditions, and animal health status.

    Science.gov (United States)

    Schreier, Christina; Kremer, Werner; Huber, Fritz; Neumann, Sindy; Pagel, Philipp; Lienemann, Kai; Pestel, Sabine

    2013-01-01

    Spectroscopic analysis of urine samples from laboratory animals can be used to predict the efficacy and side effects of drugs. This employs methods combining (1)H NMR spectroscopy with quantification of biomarkers or with multivariate data analysis. The most critical steps in data evaluation are analytical reproducibility of NMR data (collection, storage, and processing) and the health status of the animals, which may influence urine pH and osmolarity. We treated rats with a solvent, a diuretic, or a nephrotoxicant and collected urine samples. Samples were titrated to pH 3 to 9, or salt concentrations increased up to 20-fold. The effects of storage conditions and freeze-thaw cycles were monitored. Selected metabolites and multivariate data analysis were evaluated after (1)H NMR spectroscopy. We showed that variation of pH from 3 to 9 and increases in osmolarity up to 6-fold had no effect on the quantification of the metabolites or on multivariate data analysis. Storage led to changes after 14 days at 4°C or after 12 months at -20°C, independent of sample composition. Multiple freeze-thaw cycles did not affect data analysis. Reproducibility of NMR measurements is not dependent on sample composition under physiological or pathological conditions.

  11. Simultaneous analysis of amino acid and organic acid by NMR spectrometry, 2. Diagnostic aids for inborn error of metabolism

    Energy Technology Data Exchange (ETDEWEB)

    Koda, Naoya; Yamaguchi, Shuichi; Mori, Takeshi.

    1987-09-01

    Analysis of urine from patients with inborn error of metabolism were studied by /sup 1/H-nuclear magnetic resonance (NMR) spectrometry. Diseases studied were as follows; phenylketonuria, biotin responsive multiple carboxylase deficiency, non-ketotic hyperglycinemia, 3-ketothiolase deficiency, alkaptonuria, methylmalonic acidemia, isovaleric acidemia, glutaric aciduria, argininosuccinic aciduria and hyperornithinemia. In each disease, specific metabolites in urine were recognized by NMR spectrometry. This method is accomplished within 10 minutes with non-treated small volume of urine and will be successfully available for the screening andor diagnosis of inherited metabolic diseases of amino acid and organic acid.

  12. Chemometric analysis applied in 1H HR-MAS NMR and FT-IR data for chemotaxonomic distinction of intact lichen samples

    International Nuclear Information System (INIS)

    Alcantara, Glaucia Braz; Honda, Neli Kika; Castro Ferreira, Marcia Miguel; Ferreira, Antonio Gilberto

    2007-01-01

    This paper describes the potentiality of chemometric analysis applied in 1 H HR-MAS NMR and FT-IR data for lichen chemotaxonomic investigations. Lichens present a difficult morphologic differentiation and the chemical analyses are frequently employed for their taxonomic classification, mainly due to the secondary metabolites to be relatively constant for these organisms. The lichen chemotaxonomic classification is usually carried out by color reactions, chromatography, fluorescence and mass spectrometry analysis, where the identification is obtained by one or more techniques. There are some papers which use the carbohydrate content in chemotaxonomy investigation. However, the majority of these techniques involve laborious and time consuming sample pre-treatment. This work focuses on application of 1 H high resolution magic angle spinning - nuclear magnetic resonance (HR-MAS NMR) and Fourier transform infrared (FT-IR) associated with chemometric analysis to intact samples. In comparison to other traditional techniques, 1 H HR-MAS NMR and FT-IR allied with chemometrics provided a fast and economic method for lichen chemotaxonomy. Both methods were useful for lichen analysis and permitted the satisfactory distinction among families, genera and species, although better results were achieved for FT-IR data

  13. Chemometric analysis applied in {sup 1}H HR-MAS NMR and FT-IR data for chemotaxonomic distinction of intact lichen samples

    Energy Technology Data Exchange (ETDEWEB)

    Alcantara, Glaucia Braz [Departamento de Quimica, Universidade Federal de Sao Carlos, P.O. Box 676, CEP 13565-905, Sao Carlos/SP (Brazil)]. E-mail: glabraz@yahoo.com.br; Honda, Neli Kika [Departamento de Quimica, Universidade Federal de Mato Grosso do Sul, P.O. Box 549, CEP 79070-900, Campo Grande/MS (Brazil); Castro Ferreira, Marcia Miguel [Instituto de Quimica, Universidade Estadual de Campinas, P.O. Box 6154, CEP 13084-971, Campinas/SP (Brazil); Ferreira, Antonio Gilberto [Departamento de Quimica, Universidade Federal de Sao Carlos, P.O. Box 676, CEP 13565-905, Sao Carlos/SP (Brazil)

    2007-07-09

    This paper describes the potentiality of chemometric analysis applied in {sup 1}H HR-MAS NMR and FT-IR data for lichen chemotaxonomic investigations. Lichens present a difficult morphologic differentiation and the chemical analyses are frequently employed for their taxonomic classification, mainly due to the secondary metabolites to be relatively constant for these organisms. The lichen chemotaxonomic classification is usually carried out by color reactions, chromatography, fluorescence and mass spectrometry analysis, where the identification is obtained by one or more techniques. There are some papers which use the carbohydrate content in chemotaxonomy investigation. However, the majority of these techniques involve laborious and time consuming sample pre-treatment. This work focuses on application of {sup 1}H high resolution magic angle spinning - nuclear magnetic resonance (HR-MAS NMR) and Fourier transform infrared (FT-IR) associated with chemometric analysis to intact samples. In comparison to other traditional techniques, {sup 1}H HR-MAS NMR and FT-IR allied with chemometrics provided a fast and economic method for lichen chemotaxonomy. Both methods were useful for lichen analysis and permitted the satisfactory distinction among families, genera and species, although better results were achieved for FT-IR data.

  14. Identification of heparin samples that contain impurities or contaminants by chemometric pattern recognition analysis of proton NMR spectral data

    International Nuclear Information System (INIS)

    Zang, Qingda; Keire, David A.; Buhse, Lucinda F.; Trehy, Michael L.; Wood, Richard D.; Mital, Dinesh P.; Haque, Syed; Srinivasan, Shankar; Moore, Christine M.V.; Nasr, Moheb; Al-Hakim, Ali; Welsh, William J.

    2011-01-01

    Chemometric analysis of a set of one-dimensional (1D) 1 H nuclear magnetic resonance (NMR) spectral data for heparin sodium active pharmaceutical ingredient (API) samples was employed to distinguish USP-grade heparin samples from those containing oversulfated chondroitin sulfate (OSCS) contaminant and/or unacceptable levels of dermatan sulfate (DS) impurity. Three chemometric pattern recognition approaches were implemented: classification and regression tree (CART), artificial neural network (ANN), and support vector machine (SVM). Heparin sodium samples from various manufacturers were analyzed in 2008 and 2009 by 1D 1 H NMR, strong anion-exchange high-performance liquid chromatography, and percent galactosamine in total hexosamine tests. Based on these data, the samples were divided into three groups: Heparin, DS ≤ 1.0% and OSCS = 0%; DS, DS > 1.0% and OSCS = 0%; and OSCS, OSCS > 0% with any content of DS. Three data sets corresponding to different chemical shift regions (1.95-2.20, 3.10-5.70, and 1.95-5.70 ppm) were evaluated. While all three chemometric approaches were able to effectively model the data in the 1.95-2.20 ppm region, SVM was found to substantially outperform CART and ANN for data in the 3.10-5.70 ppm region in terms of classification success rate. A 100% prediction rate was frequently achieved for discrimination between heparin and OSCS samples. The majority of classification errors between heparin and DS involved cases where the DS content was close to the 1.0% DS borderline between the two classes. When these borderline samples were removed, nearly perfect classification results were attained. Satisfactory results were achieved when the resulting models were challenged by test samples containing blends of heparin APIs spiked with non-, partially, or fully oversulfated chondroitin sulfate A, heparan sulfate, or DS at the 1.0%, 5.0%, and 10.0% (w/w) levels. This study demonstrated that the combination of 1D 1 H NMR spectroscopy with multivariate

  15. Identification of heparin samples that contain impurities or contaminants by chemometric pattern recognition analysis of proton NMR spectral data

    Energy Technology Data Exchange (ETDEWEB)

    Zang, Qingda [University of Medicine and Dentistry of New Jersey, Department of Pharmacology, Robert Wood Johnson Medical School, Piscataway, NJ (United States); Snowdon, Inc., Monmouth Junction, NJ (United States); University of Medicine and Dentistry of New Jersey, Department of Health Informatics, School of Health Related Professions, Newark, NJ (United States); Keire, David A.; Buhse, Lucinda F.; Trehy, Michael L. [Food and Drug Administration, CDER, Division of Pharmaceutical Analysis, St. Louis, MO (United States); Wood, Richard D. [Snowdon, Inc., Monmouth Junction, NJ (United States); Mital, Dinesh P.; Haque, Syed; Srinivasan, Shankar [University of Medicine and Dentistry of New Jersey, Department of Health Informatics, School of Health Related Professions, Newark, NJ (United States); Moore, Christine M.V.; Nasr, Moheb; Al-Hakim, Ali [Food and Drug Administration, CDER, Office of New Drug Quality Assessment, Silver Spring, MD (United States); Welsh, William J. [University of Medicine and Dentistry of New Jersey, Department of Pharmacology, Robert Wood Johnson Medical School, Piscataway, NJ (United States)

    2011-08-15

    Chemometric analysis of a set of one-dimensional (1D) {sup 1}H nuclear magnetic resonance (NMR) spectral data for heparin sodium active pharmaceutical ingredient (API) samples was employed to distinguish USP-grade heparin samples from those containing oversulfated chondroitin sulfate (OSCS) contaminant and/or unacceptable levels of dermatan sulfate (DS) impurity. Three chemometric pattern recognition approaches were implemented: classification and regression tree (CART), artificial neural network (ANN), and support vector machine (SVM). Heparin sodium samples from various manufacturers were analyzed in 2008 and 2009 by 1D {sup 1}H NMR, strong anion-exchange high-performance liquid chromatography, and percent galactosamine in total hexosamine tests. Based on these data, the samples were divided into three groups: Heparin, DS {<=} 1.0% and OSCS = 0%; DS, DS > 1.0% and OSCS = 0%; and OSCS, OSCS > 0% with any content of DS. Three data sets corresponding to different chemical shift regions (1.95-2.20, 3.10-5.70, and 1.95-5.70 ppm) were evaluated. While all three chemometric approaches were able to effectively model the data in the 1.95-2.20 ppm region, SVM was found to substantially outperform CART and ANN for data in the 3.10-5.70 ppm region in terms of classification success rate. A 100% prediction rate was frequently achieved for discrimination between heparin and OSCS samples. The majority of classification errors between heparin and DS involved cases where the DS content was close to the 1.0% DS borderline between the two classes. When these borderline samples were removed, nearly perfect classification results were attained. Satisfactory results were achieved when the resulting models were challenged by test samples containing blends of heparin APIs spiked with non-, partially, or fully oversulfated chondroitin sulfate A, heparan sulfate, or DS at the 1.0%, 5.0%, and 10.0% (w/w) levels. This study demonstrated that the combination of 1D {sup 1}H NMR spectroscopy

  16. A Solid-State NMR Experiment: Analysis of Local Structural Environments in Phosphate Glasses

    Science.gov (United States)

    Anderson, Stanley E.; Saiki, David; Eckert, Hellmut; Meise-Gresch, Karin

    2004-01-01

    An experiment that can be used to directly study the local chemical environments of phosphorus in solid amorphous materials is demonstrated. The experiment aims at familiarizing the students of chemistry with the principles of solid-state NMR, by having them synthesize a simple phosphate glass, and making them observe the (super 31)P NMR spectrum,…

  17. Standardless multicomponent qNMR analysis of compounds with overlapped resonances based on the combination of ICA and PULCON.

    Science.gov (United States)

    Monakhova, Yulia B; Lachenmeier, Dirk W; Kuballa, Thomas; Mushtakova, Svetlana P

    2015-10-01

    A fast and reliable nuclear magnetic resonance (NMR) method for quantitative analysis of targeted compounds with overlapped signals in complex mixtures has been established. The method is based on the combination of chemometric treatment for spectra deconvolution and the PULCON principle (pulse length based concentration determination) for quantification. Independent component analysis (ICA) (mutual information least dependent component analysis (MILCA) algorithm) was applied for spectra deconvolution in up to six component mixtures with known composition. The resolved matrices (independent components, ICs and ICA scores) were used for identification of analytes, calculating their relative concentrations and absolute integral intensity of selected resonances. The absolute analyte concentrations in multicomponent mixtures and authentic samples were then calculated using the PULCON principle. Instead of conventional application of absolute integral intensity in case of undisturbed signals, the multiplication of resolved IC absolute integral and its relative concentration in the mixture for each component was used. Correction factors that are required for quantification and are unique for each analyte were also estimated. The proposed method was applied for analysis of up to five components in lemon and orange juice samples with recoveries between 90% and 111%. The total duration of analysis is approximately 45 min including measurements, spectra decomposition and quantification. The results demonstrated that the proposed method is a promising tool for rapid simultaneous quantification of up to six components in case of spectral overlap and the absence of reference materials. Copyright © 2015 John Wiley & Sons, Ltd.

  18. Structure and composition analysis of natural gas hydrates: 13C NMR spectroscopic and gas uptake measurements of mixed gas hydrates.

    Science.gov (United States)

    Seo, Yutaek; Kang, Seong-Pil; Jang, Wonho

    2009-09-03

    Gas hydrates are becoming an attractive way of storing and transporting large quantities of natural gas, although there has been little effort to understand the preferential occupation of heavy hydrocarbon molecules in hydrate cages. In this work, we present the formation kinetics of mixed hydrate based on a gas uptake measurement during hydrate formation, and how the compositions of the hydrate phase are varied under corresponding formation conditions. We also examine the effect of silica gel pores on the physical properties of mixed hydrate, including thermodynamic equilibrium, formation kinetics, and hydrate compositions. It is expected that the enclathration of ethane and propane is faster than that of methane early stage hydrate formation, and later methane becomes the dominant component to be enclathrated due to depletion of heavy hydrocarbons in the vapor phase. The composition of the hydrate phase seems to be affected by the consumed amount of natural gas, which results in a variation of heating value of retrieved gas from mixed hydrates as a function of formation temperature. 13C NMR experiments were used to measure the distribution of hydrocarbon molecules over the cages of hydrate structure when it forms either from bulk water or water in silica gel pores. We confirm that 70% of large cages of mixed hydrate are occupied by methane molecules when it forms from bulk water; however, only 19% of large cages of mixed hydrate are occupied by methane molecules when it forms from water in silica gel pores. This result indicates that the fractionation of the hydrate phase with heavy hydrocarbon molecules is enhanced in silica gel pores. In addition when heavy hydrocarbon molecules are depleted in the vapor phase during the formation of mixed hydrate, structure I methane hydrate forms instead of structure II mixed hydrate and both structures coexist together, which is also confirmed by 13C NMR spectroscopic analysis.

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

    Science.gov (United States)

    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. Copyright © 2015 Elsevier B.V. All rights reserved.

  20. Analysis of Polycyclic Aromatic Hydrocarbon (PAH Mixtures Using Diffusion-Ordered NMR Spectroscopy and Adsorption by Powdered Activated Carbon and Biochar

    Directory of Open Access Journals (Sweden)

    Dong An

    2018-03-01

    Full Text Available Analysis of polycyclic aromatic hydrocarbons (PAHs in air and water sources is a key part of environmental chemistry research, since most PAHs are well known to be associated with negative health impacts on humans. This study explores an approach for analyzing PAH mixtures with advanced nuclear magnetic resonance (NMR spectroscopic techniques including high-resolution one-dimensional (1D NMR spectroscopy and diffusion-ordered NMR spectroscopy (DOSY NMR. With this method, different kinds of PAHs can be detected and differentiated from a mixture with high resolution. The adsorption process of PAH mixtures by PAC and biochar was studied to understand the mechanism and assess the method.

  1. 13C-NMR chemical shift databases as a quick tool to evaluate structural models of humic substances

    DEFF Research Database (Denmark)

    Nyrop Albers, Christian; Hansen, Poul Erik

    2010-01-01

    Models for humic and fulvic acids are discussed based on 13C liquid state NMR spectra combined with results from elemental analysis and titration studies. The analysis of NMR spectra is based on a full reconstruction of the NMR spectrum done with help of 13C-NMR data bases by adding up chemical...... side missing structural elements in the models can be suggested. A number of proposed structures for humic and fulvic acids are discussed based on the above analysis....

  2. 1H NMR Spectroscopy and MVA Analysis of Diplodus sargus Eating the Exotic Pest Caulerpa cylindracea.

    Science.gov (United States)

    De Pascali, Sandra A; Del Coco, Laura; Felline, Serena; Mollo, Ernesto; Terlizzi, Antonio; Fanizzi, Francesco P

    2015-06-05

    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.

  3. Molecular structure, vibrational analysis (FT-IR, FT-Raman), NMR, UV, NBO and HOMO-LUMO analysis of N,N-Diphenyl Formamide based on DFT calculations.

    Science.gov (United States)

    Mathammal, R; Monisha, N R; Yasaswini, S; Krishnakumar, V

    2015-03-15

    In this work, the vibrational spectral analysis is carried out by using Raman and infrared spectroscopy in the range 4000-400 cm(-1) and 4000-50 cm(-1) respectively for N,N-Diphenyl Formamide (DPF) molecule. The optimized molecular structures, vibrational frequencies and corresponding vibrational assignments, nuclear magnetic resonance (NMR) and ultraviolet-visible (UV-VIS) spectra of the title molecule are evaluated using density functional theory (DFT) with standard B3LYP/6-31G(d,p) basis set. The harmonic vibrational frequencies are calculated and the scaled values have been compared with experimental FT-IR and FT-Raman spectra. The observed and calculated frequencies are found to be in good agreement. The stability of the molecule arising from hyper conjugative interactions and the charge delocalization has been analyzed using natural bond (NBO) analysis. The possible electronic transitions are determined by HOMO-LUMO orbital shapes and their energies. Thermodynamic properties (heat capacity, entropy and enthalpy) and the first hyperpolarizability of the title compound are calculated. The Mulliken charges and electric dipole moment of the molecule are computed using DFT calculations. The (1)H and (13)C nuclear magnetic resonance (NMR) chemical shift of the molecules are calculated by the gauge independent atomic orbital (GIAO) method and compared with experimental results. Copyright © 2014 Elsevier B.V. All rights reserved.

  4. Atomic structure of icosahedral B4C boron carbide from a first principles analysis of NMR spectra.

    Science.gov (United States)

    Mauri, F; Vast, N; Pickard, C J

    2001-08-20

    Density functional theory is demonstrated to reproduce the 13C and 11B NMR chemical shifts of icosahedral boron carbides with sufficient accuracy to extract previously unresolved structural information from experimental NMR spectra. B4C can be viewed as an arrangement of 3-atom linear chains and 12-atom icosahedra. According to our results, all the chains have a CBC structure. Most of the icosahedra have a B11C structure with the C atom placed in a polar site, and a few percent have a B (12) structure or a B10C2 structure with the two C atoms placed in two antipodal polar sites.

  5. 1H NMR-Based Analysis of Serum Metabolites in Monocrotaline-Induced Pulmonary Arterial Hypertensive Rats

    Directory of Open Access Journals (Sweden)

    Taijie Lin

    2016-01-01

    Full Text Available Aims. To study the changes of the metabolic profile during the pathogenesis in monocrotaline (MCT induced pulmonary arterial hypertension (PAH. Methods. Forty male Sprague-Dawley (SD rats were randomly divided into 5 groups (n=8, each. PAH rats were induced by a single dose intraperitoneal injection of 60 mg/kg MCT, while 8 rats given intraperitoneal injection of 1 ml normal saline and scarified in the same day (W0 served as control. Mean pulmonary arterial pressure (mPAP was measured through catherization. The degree of right ventricular hypertrophy and pulmonary hyperplasia were determined at the end of first to fourth weeks; nuclear magnetic resonance (NMR spectra of sera were then acquired for the analysis of metabolites. Principal component analysis (PCA and orthogonal partial least-squares discriminant analysis (OPLS-DA were used to discriminate different metabolic profiles. Results. The prominent changes of metabolic profiles were seen during these four weeks. Twenty specific metabolites were identified, which were mainly involved in lipid metabolism, glycolysis, energy metabolism, ketogenesis, and methionine metabolism. Profiles of correlation between these metabolites in each stage changed markedly, especially in the fourth week. Highly activated methionine and betaine metabolism pathways were selected by the pathway enrichment analysis. Conclusions. Metabolic dysfunction is involved in the development and progression of PAH.

  6. Evaluation of standard and advanced preprocessing methods for the univariate analysis of blood serum 1H-NMR spectra.

    Science.gov (United States)

    De Meyer, Tim; Sinnaeve, Davy; Van Gasse, Bjorn; Rietzschel, Ernst-R; De Buyzere, Marc L; Langlois, Michel R; Bekaert, Sofie; Martins, José C; Van Criekinge, Wim

    2010-10-01

    Proton nuclear magnetic resonance ((1)H-NMR)-based metabolomics enables the high-resolution and high-throughput assessment of a broad spectrum of metabolites in biofluids. Despite the straightforward character of the experimental methodology, the analysis of spectral profiles is rather complex, particularly due to the requirement of numerous data preprocessing steps. Here, we evaluate how several of the most common preprocessing procedures affect the subsequent univariate analyses of blood serum spectra, with a particular focus on how the standard methods perform compared to more advanced examples. Carr-Purcell-Meiboom-Gill 1D (1)H spectra were obtained for 240 serum samples from healthy subjects of the Asklepios study. We studied the impact of different preprocessing steps--integral (standard method) and probabilistic quotient normalization; no, equidistant (standard), and adaptive-intelligent binning; mean (standard) and maximum bin intensity data summation--on the resonance intensities of three different types of metabolites: triglycerides, glucose, and creatinine. The effects were evaluated by correlating the differently preprocessed NMR data with the independently measured metabolite concentrations. The analyses revealed that the standard methods performed inferiorly and that a combination of probabilistic quotient normalization after adaptive-intelligent binning and maximum intensity variable definition yielded the best overall results (triglycerides, R = 0.98; glucose, R = 0.76; creatinine, R = 0.70). Therefore, at least in the case of serum metabolomics, these or equivalent methods should be preferred above the standard preprocessing methods, particularly for univariate analyses. Additional optimization of the normalization procedure might further improve the analyses.

  7. Proton Nuclear Magnetic Resonance (1H NMR) Spectroscopy-Based Analysis of Lipid Components in Serum/Plasma of Patients with Duchenne Muscular Dystrophy (DMD).

    Science.gov (United States)

    Srivastava, Niraj Kumar

    2018-01-01

    Proton nuclear magnetic resonance spectroscopy ( 1 H NMR) is a useful tool for the analysis of lipid components in biofluids such as serum/plasma. Such tool is applied for the analysis of lipid components in serum/plasma of patients with Duchenne muscular dystrophy (DMD). The practical approach of sampling, storage, lipid extraction procedure, sample preparation before performing the 1 H NMR spectroscopy experiments is presented. All the experimental parameters of NMR spectroscopy are also described. Details of the assignments of lipid components (qualitative analysis) and quantification of particular lipid components (quantitative analysis) are explained.

  8. Discovery of an Interleukin 33 Inhibitor by Molecular Docking Simulation and NMR Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Young Kwan; Cho, Sang Hyun; Mushtaq, Ameeq UI; Jung, Yong Woo; Byun, Youngjoo; Jeon, Young Ho [Korea University, Sejong (Korea, Republic of); Cho, Haelim [T and J Tech Inc., Seoul (Korea, Republic of)

    2016-02-15

    We identified an inhibitor, which is able to bind to the IL-33 and potentially interfere with ST2 binding by means of docking-based virtual screening and 2D NMR binding analyses. Using this compound, the NMR Chemical shift perturbation (CSP) of IL-33 signals were analyzed and mapped on the structure of IL-33, showing that the identified compound binds at the interface of IL-33 and ST2 binding.

  9. NMR signal analysis in the large COMPASS $^{14}$NH$_{3}$ target

    CERN Document Server

    Koivuniemi, J; Hess, C; Kisselev, Y U; Meyer, W; Radtke, E; Reicherz, G; Doshita, N; Iwata, T; Kondo, K; Michigami, T

    2009-01-01

    In the large COMPASS polarized proton target the 1508 cm$^{3}$ of irradiated granular ammonia is polarized with dynamic nuclear polarization method using 4 mm microwaves in 2.5 T eld. The nuclear polarization up to 90 - 93 % is determined with cw NMR. The properties of the observed ammonia proton signals are described and spin thermodynamics in high elds is presented. Also the second moment of the NMR line is estimated.

  10. Recommendations and Standardization of Biomarker Quantification Using NMR-Based Metabolomics with Particular Focus on Urinary Analysis.

    Science.gov (United States)

    Emwas, Abdul-Hamid; Roy, Raja; McKay, Ryan T; Ryan, Danielle; Brennan, Lorraine; Tenori, Leonardo; Luchinat, Claudio; Gao, Xin; Zeri, Ana Carolina; Gowda, G A Nagana; Raftery, Daniel; Steinbeck, Christoph; Salek, Reza M; Wishart, David S

    2016-02-05

    NMR-based metabolomics has shown considerable promise in disease diagnosis and biomarker discovery because it allows one to nondestructively identify and quantify large numbers of novel metabolite biomarkers in both biofluids and tissues. Precise metabolite quantification is a prerequisite to move any chemical biomarker or biomarker panel from the lab to the clinic. Among the biofluids commonly used for disease diagnosis and prognosis, urine has several advantages. It is abundant, sterile, and easily obtained, needs little sample preparation, and does not require invasive medical procedures for collection. Furthermore, urine captures and concentrates many "unwanted" or "undesirable" compounds throughout the body, providing a rich source of potentially useful disease biomarkers; however, incredible variation in urine chemical concentrations makes analysis of urine and identification of useful urinary biomarkers by NMR challenging. We discuss a number of the most significant issues regarding NMR-based urinary metabolomics with specific emphasis on metabolite quantification for disease biomarker applications and propose data collection and instrumental recommendations regarding NMR pulse sequences, acceptable acquisition parameter ranges, relaxation effects on quantitation, proper handling of instrumental differences, sample preparation, and biomarker assessment.

  11. Recommendations and Standardization of Biomarker Quantification Using NMR-based Metabolomics with Particular Focus on Urinary Analysis

    KAUST Repository

    Emwas, Abdul-Hamid M.

    2016-01-08

    NMR-based metabolomics has shown considerable promise in disease diagnosis and biomarker discovery because it allows one to non-destructively identify and quantify large numbers of novel metabolite biomarkers in both biofluids and tissues. Indeed, precise metabolite quantification is a necessary prerequisite to move any chemical biomarker or biomarker panel from the lab into the clinic. Among the many biofluids (urine, serum, plasma, cerebrospinal fluid and saliva) commonly used for disease diagnosis and prognosis, urine has several advantages. It is abundant, sterile, easily obtained, needs little sample preparation and does not require any invasive medical procedures for collection. Furthermore, urine captures and concentrates many “unwanted” or “undesirable” compounds throughout the body, thereby providing a rich source of potentially useful disease biomarkers. However, the incredible variation in urine chemical concentrations due to effects such as gender, age, diet, life style, health conditions, and physical activity make the analysis of urine and the identification of useful urinary biomarkers by NMR quite challenging. In this review, we discuss a number of the most significant issues regarding NMR-based urinary metabolomics with a specific emphasis on metabolite quantification for disease biomarker applications. We also propose a number of data collection and instrumental recommendations regarding NMR pulse sequences, acceptable acquisition parameter ranges, relaxation effects on quantitation, proper handling of instrumental differences, as well as recommendations regarding sample preparation and biomarker assessment.

  12. Analysis of porous media and objects of cultural heritage by mobile NMR

    International Nuclear Information System (INIS)

    Haber, Agnes

    2012-01-01

    Low-field NMR techniques are used to study porous system, from simple to complex structures, and objects of cultural heritage. It is shown that NMR relaxometry can be used to study the fluid dynamics inside a porous system. A simple theoretical model for multi-site relaxation exchange NMR is used to extract exchange kinetic parameters when applied on a model porous systems. It provides a first step towards the study of more complex systems, where continuous relaxation distributions are present, such as soil systems or building materials. Moisture migration is observed in the soil systems with the help of 1D and 2D NMR relaxometry methods. In case of the concrete samples, the difference in composition makes a significant difference in the ability of water uptake. The single-sided NMR sensor proves to be a useful tool for on-site measurements. This is very important also in the case of the cultural heritage objects, as most of the objects can not be moved out of their environment. Mobile NMR turns out to be a simple but reliable and powerful tool to investigate moisture distributions and pore structures in porous media as well as the conservation state and history of objects of cultural heritage.

  13. A solid-phase extraction procedure coupled to 1H NMR, with chemometric analysis, to seek reliable markers of the botanical origin of honey.

    Science.gov (United States)

    Beretta, Giangiacomo; Caneva, Enrico; Regazzoni, Luca; Bakhtyari, Nazanin Golbamaki; Maffei Facino, Roberto

    2008-07-14

    The aim of this work was to establish an analytical method for identifying the botanical origin of honey, as an alternative to conventional melissopalynological, organoleptic and instrumental methods (gas-chromatography coupled to mass spectrometry (GC-MS), high-performance liquid chromatography HPLC). The procedure is based on the (1)H nuclear magnetic resonance (NMR) profile coupled, when necessary, with electrospray ionisation-mass spectrometry (ESI-MS) and two-dimensional NMR analyses of solid-phase extraction (SPE)-purified honey samples, followed by chemometric analyses. Extracts of 44 commercial Italian honeys from 20 different botanical sources were analyzed. Honeydew, chestnut and linden honeys showed constant, specific, well-resolved resonances, suitable for use as markers of origin. Honeydew honey contained the typical resonances of an aliphatic component, very likely deriving from the plant phloem sap or excreted into it by sap-sucking aphids. Chestnut honey contained the typical signals of kynurenic acid and some structurally related metabolite. In linden honey the (1)H NMR profile gave strong signals attributable to the mono-terpene derivative cyclohexa-1,3-diene-1-carboxylic acid (CDCA) and to its 1-O-beta-gentiobiosyl ester (CDCA-GBE). These markers were not detectable in the other honeys, except for the less common nectar honey from rosa mosqueta. We compared and analyzed the data by multivariate techniques. Principal component analysis found different clusters of honeys based on the presence of these specific markers. The results, although obviously only preliminary, suggest that the (1)H NMR profile (with HPLC-MS analysis when necessary) can be used as a reference framework for identifying the botanical origin of honey.

  14. A solid-phase extraction procedure coupled to {sup 1}H NMR, with chemometric analysis, to seek reliable markers of the botanical origin of honey

    Energy Technology Data Exchange (ETDEWEB)

    Beretta, Giangiacomo [Istituto di Chimica Farmaceutica e Tossicologica ' Pietro Pratesi' , Faculty of Pharmacy, University of Milan, via Mangiagalli 25, 20133 Milan (Italy)], E-mail: giangiacomo.beretta@unimi.it; Caneva, Enrico [Ciga - Centro Interdipartimentale Grandi Apparecchiature, University of Milan, via Golgi 19, 20133 Milan (Italy); Regazzoni, Luca; Bakhtyari, Nazanin Golbamaki; Maffei Facino, Roberto [Istituto di Chimica Farmaceutica e Tossicologica ' Pietro Pratesi' , Faculty of Pharmacy, University of Milan, via Mangiagalli 25, 20133 Milan (Italy)

    2008-07-14

    The aim of this work was to establish an analytical method for identifying the botanical origin of honey, as an alternative to conventional melissopalynological, organoleptic and instrumental methods (gas-chromatography coupled to mass spectrometry (GC-MS), high-performance liquid chromatography HPLC). The procedure is based on the {sup 1}H nuclear magnetic resonance (NMR) profile coupled, when necessary, with electrospray ionisation-mass spectrometry (ESI-MS) and two-dimensional NMR analyses of solid-phase extraction (SPE)-purified honey samples, followed by chemometric analyses. Extracts of 44 commercial Italian honeys from 20 different botanical sources were analyzed. Honeydew, chestnut and linden honeys showed constant, specific, well-resolved resonances, suitable for use as markers of origin. Honeydew honey contained the typical resonances of an aliphatic component, very likely deriving from the plant phloem sap or excreted into it by sap-sucking aphids. Chestnut honey contained the typical signals of kynurenic acid and some structurally related metabolite. In linden honey the {sup 1}H NMR profile gave strong signals attributable to the mono-terpene derivative cyclohexa-1,3-diene-1-carboxylic acid (CDCA) and to its 1-O-{beta}-gentiobiosyl ester (CDCA-GBE). These markers were not detectable in the other honeys, except for the less common nectar honey from rosa mosqueta. We compared and analyzed the data by multivariate techniques. Principal component analysis found different clusters of honeys based on the presence of these specific markers. The results, although obviously only preliminary, suggest that the {sup 1}H NMR profile (with HPLC-MS analysis when necessary) can be used as a reference framework for identifying the botanical origin of honey.

  15. A solid-phase extraction procedure coupled to 1H NMR, with chemometric analysis, to seek reliable markers of the botanical origin of honey

    International Nuclear Information System (INIS)

    Beretta, Giangiacomo; Caneva, Enrico; Regazzoni, Luca; Bakhtyari, Nazanin Golbamaki; Maffei Facino, Roberto

    2008-01-01

    The aim of this work was to establish an analytical method for identifying the botanical origin of honey, as an alternative to conventional melissopalynological, organoleptic and instrumental methods (gas-chromatography coupled to mass spectrometry (GC-MS), high-performance liquid chromatography HPLC). The procedure is based on the 1 H nuclear magnetic resonance (NMR) profile coupled, when necessary, with electrospray ionisation-mass spectrometry (ESI-MS) and two-dimensional NMR analyses of solid-phase extraction (SPE)-purified honey samples, followed by chemometric analyses. Extracts of 44 commercial Italian honeys from 20 different botanical sources were analyzed. Honeydew, chestnut and linden honeys showed constant, specific, well-resolved resonances, suitable for use as markers of origin. Honeydew honey contained the typical resonances of an aliphatic component, very likely deriving from the plant phloem sap or excreted into it by sap-sucking aphids. Chestnut honey contained the typical signals of kynurenic acid and some structurally related metabolite. In linden honey the 1 H NMR profile gave strong signals attributable to the mono-terpene derivative cyclohexa-1,3-diene-1-carboxylic acid (CDCA) and to its 1-O-β-gentiobiosyl ester (CDCA-GBE). These markers were not detectable in the other honeys, except for the less common nectar honey from rosa mosqueta. We compared and analyzed the data by multivariate techniques. Principal component analysis found different clusters of honeys based on the presence of these specific markers. The results, although obviously only preliminary, suggest that the 1 H NMR profile (with HPLC-MS analysis when necessary) can be used as a reference framework for identifying the botanical origin of honey

  16. NMR-based screening method for transglutaminases: rapid analysis of their substrate specificities and reaction rates.

    Science.gov (United States)

    Shimba, Nobuhisa; Yokoyama, Kei-ichi; Suzuki, Ei-ichiro

    2002-03-13

    Incorporation of inter- or intramolecular covalent cross-links into food proteins with microbial transglutaminase (MTG) improves the physical and textural properties of many food proteins such as tofu, boiled fish paste, and sausage. Other transglutaminases (TGases) are expected to be used in the same way, and also to extend the scope of industrial applications to materials, drugs, and so on. The TGases have great diversity, not only in amino acid sequence and size, but also in their substrate specificities and catalytic activities, and therefore, it is quite difficult to estimate their reactivity. We have developed an NMR-based method using the enzymatic labeling technique (ELT) for simultaneous analysis of the substrate specificities and reaction rates of TGases. It is quite useful for comparing the existing TGases and for screening new TGases or TGases variants. This method has shown that MTG is superior for industrial use because of its lower substrate specificity compared with those of guinea pig liver transglutaminase (GTG) and red sea bream liver transglutaminase (FTG). We have also found that an MTG variant lacking an N-terminal aspartic acid residue has higher activity than that of the native enzyme.

  17. Metabolic Effects of Hypoxia in Colorectal Cancer by 13C NMR Isotopomer Analysis

    Directory of Open Access Journals (Sweden)

    Ana M. Abrantes

    2014-01-01

    Full Text Available 13C NMR isotopomer analysis was used to characterize intermediary metabolism in three colorectal cancer cell lines (WiDr, LS1034, and C2BBe1 and determine the “metabolic remodeling” that occurs under hypoxia. Under normoxia, the three colorectal cancer cell lines present high rates of lactate production and can be seen as “Warburg” like cancer cells independently of substrate availability, since such profile was dominant at both high and low glucose media contents. The LS1034 was the less glycolytic of the three cell lines and was the most affected by the event of hypoxia, raising abruptly glucose consumption and lactate production. The other two colorectal cell lines, WiDr and C2BBe1, adapted better to hypoxia and were able to maintain their oxidative fluxes even at the very low levels of oxygen. These differential metabolic behaviors of the three colorectal cell lines show how important an adequate knowledge of the “metabolic remodeling” that follows a given cancer treatment is towards the correct (redesign of therapeutic strategies against cancer.

  18. Interactions of ionic liquids and acetone: thermodynamic properties, quantum-chemical calculations, and NMR analysis.

    Science.gov (United States)

    Ruiz, Elia; Ferro, Victor R; Palomar, Jose; Ortega, Juan; Rodriguez, Juan Jose

    2013-06-20

    The interactions between ionic liquids (ILs) and acetone have been studied to obtain a further understanding of the behavior of their mixtures, which generally give place to an exothermic process, mutual miscibility, and negative deviation of Raoult's law. COSMO-RS was used as a suitable computational method to systematically analyze the excess enthalpy of IL-acetone systems (>300), in terms of the intermolecular interactions contributing to the mixture behavior. Spectroscopic and COSMO-RS results indicated that acetone, as a polar compound with strong hydrogen bond acceptor character, in most cases, establishes favorable hydrogen bonding with ILs. This interaction is strengthened by the presence of an acidic cation and an anion with dispersed charge and non-HB acceptor character in the IL. COSMO-RS predictions indicated that gas-liquid and vapor-liquid equilibrium data for IL-acetone systems can be finely tuned by the IL selection, that is, acting on the intermolecular interactions between the molecular and ionic species in the liquid phase. NMR measurements for IL-acetone mixtures at different concentrations were also carried out. Quantum-chemical calculations by using molecular clusters of acetone and IL species were finally performed. These results provided additional evidence of the main role played by hydrogen bonding in the behavior of systems containing ILs and HB acceptor compounds, such as acetone.

  19. Analysis of the mechanical properties and characterization by solid state 13C NMR of recycled EVA copolymer/silica composites

    Directory of Open Access Journals (Sweden)

    Giovanni Chaves Stael

    2005-09-01

    Full Text Available The incorporation of micrometer sized silica particles on poly (ethylene-co-vinyl acetate - EVA - residues from the footwear industry was evaluated. The effects of the processing parameters - temperature and mixing ratio - on the mechanical behavior of molded plates of neat recycled EVA and EVA/silica composites were also investigated. The mechanical properties measured by the tensile test, the fractographic analysis by scanning electron microscopy (SEM, and the 13C Nuclear Magnetic Resonance (NMR showed a reduced EVA to silica compatibility. Therefore, incorporation of untreated silica to recycled EVA copolymer produced a slight decrease on the mechanical performance of EVA/silica composites in respect to neat EVA copolymer. The NMR analysis also shows that the crosslinking process on recycled EVA may be occurring at the carbonyl group.

  20. An in-depth analysis of the biological functional studies based on the NMR M2 channel structure of influenza A virus

    International Nuclear Information System (INIS)

    Huang Ribo; Du Qishi; Wang Chenghua; Chou, K.-C.

    2008-01-01

    The long-sought three-dimensional structure of the M2 proton channel of influenza A virus was successfully determined recently by the high-resolution NMR [J.R. Schnell, J.J. Chou, Structure and mechanism of the M2 proton channel of influenza A virus, Nature 451 (2008) 591-595]. Such a milestone work has provided a solid structural basis for studying drug-resistance problems. However, the action mechanism revealed from the NMR structure is completely different from the traditional view and hence prone to be misinterpreted as 'conflicting' with some previous biological functional studies. To clarify this kind of confusion, an in-depth analysis was performed for these functional studies, particularly for the mutations D44N, D44A and N44D on position 44, and the mutations on positions 27-38. The analyzed results have provided not only compelling evidences to further validate the NMR structure but also very useful clues for dealing with the drug-resistance problems and developing new effective drugs against H5N1 avian influenza virus, an impending threat to human beings.

  1. Nontargeted nuclear magnetic resonance (NMR) analysis to detect hazardous substances including methanol in unrecorded alcohol from Novosibirsk, Russia

    OpenAIRE

    Hausler, Thomas; Okaru,  Alex O.; Neufeld, Maria; Rehm, Jürgen; Kuballa, Thomas; Luy, Burkhard; Lachenmeier, Dirk W.

    2016-01-01

    Nuclear magnetic resonance (NMR) spectroscopy was applied to the analysis of alcoholic products in the context of health and safety control. A total of 86 samples of unrecorded alcohol were collected in Novosibirsk and nearby cities in Russia. Sampling was based on interviews with alcohol dependent patients, and unrecorded alcohol thus defined included illegally or informally produced alcoholic products (e.g., counterfeit or home-made alcoholic beverages) or surrogate alcohol in the form of c...

  2. Animal manure phosphorus characterization by sequential chemical fractionation, release kinetics and 31P-NMR analysis

    Directory of Open Access Journals (Sweden)

    Tales Tiecher

    2014-10-01

    Full Text Available Phosphate release kinetics from manures are of global interest because sustainable plant nutrition with phosphate will be a major concern in the future. Although information on the bioavailability and chemical composition of P present in manure used as fertilizer are important to understand its dynamics in the soil, such studies are still scarce. Therefore, P extraction was evaluated in this study by sequential chemical fractionation, desorption with anion-cation exchange resin and 31P nuclear magnetic resonance (31P-NMR spectroscopy to assess the P forms in three different dry manure types (i.e. poultry, cattle and swine manure. All three methods showed that the P forms in poultry, cattle and swine dry manures are mostly inorganic and highly bioavailable. The estimated P pools showed that organic and recalcitrant P forms were negligible and highly dependent on the Ca:P ratio in manures. The results obtained here showed that the extraction of P with these three different methods allows a better understanding and complete characterization of the P pools present in the manures.

  3. Stereochemical analysis of (+)-limonene using theoretical and experimental NMR and chiroptical data

    Science.gov (United States)

    Reinscheid, F.; Reinscheid, U. M.

    2016-02-01

    Using limonene as test molecule, the success and the limitations of three chiroptical methods (optical rotatory dispersion (ORD), electronic and vibrational circular dichroism, ECD and VCD) could be demonstrated. At quite low levels of theory (mpw1pw91/cc-pvdz, IEFPCM (integral equation formalism polarizable continuum model)) the experimental ORD values differ by less than 10 units from the calculated values. The modelling in the condensed phase still represents a challenge so that experimental NMR data were used to test for aggregation and solvent-solute interactions. After establishing a reasonable structural model, only the ECD spectra prediction showed a decisive dependence on the basis set: only augmented (in the case of Dunning's basis sets) or diffuse (in the case of Pople's basis sets) basis sets predicted the position and shape of the ECD bands correctly. Based on these result we propose a procedure to assign the absolute configuration (AC) of an unknown compound using the comparison between experimental and calculated chiroptical data.

  4. Complex Mixture Analysis of Organic Compounds in Yogurt by NMR Spectroscopy

    Science.gov (United States)

    Lu, Yi; Hu, Fangyu; Miyakawa, Takuya; Tanokura, Masaru

    2016-01-01

    NMR measurements do not require separation and chemical modification of samples and therefore rapidly and directly provide non-targeted information on chemical components in complex mixtures. In this study, one-dimensional (1H, 13C, and 31P) and two-dimensional (1H-13C and 1H-31P) NMR spectroscopy were conducted to analyze yogurt without any pretreatment. 1H, 13C, and 31P NMR signals were assigned to 10 types of compounds. The signals of α/β-lactose and α/β-galactose were separately observed in the 1H NMR spectra. In addition, the signals from the acyl chains of milk fats were also successfully identified but overlapped with many other signals. Quantitative difference spectra were obtained by subtracting the diffusion ordered spectroscopy (DOSY) spectra from the quantitative 1H NMR spectra. This method allowed us to eliminate interference on the overlaps; therefore, the correct intensities of signals overlapped with those from the acyl chains of milk fat could be determined directly without separation. Moreover, the 1H-31P HMBC spectra revealed for the first time that N-acetyl-d-glucosamine-1-phosphate is contained in yogurt. PMID:27322339

  5. Extension of the geometry algorithm for the calculation of the spatial structure of protein-peptide molecules from NMR spectroscopic results

    International Nuclear Information System (INIS)

    Maiorov, V.N.; Arsen'ev, A.S.; Bystrov, V.F.

    1986-01-01

    A special supplement to the program of the distance geometry algorithm has been developed which, in the construction of the spatial structure of polypeptides, permits the taking into account of experimental NMR characteristics that are unambiguously connected with distance limitations - the spin-spin coupling constants of the H-NC/sup α/-H and H-C/sup α/C/sup β/-H protons and the rates of deuterium exchange of the amide NH groups of the main chain. In addition, the results of an analysis of spin-spin coupling constants are brought in for the empirical calculation of the intensities of the cross-peaks of the nuclear Overhauser effect in order to increase their informativeness for the distance geometry algorithm. A calculation performed by the extended program in the determination of the helical conformation of the Ala 13 -Cys 20 fragment of insectotoxin I 5 A of Buthus eupeus has shown the correctness of the proposed procedure for evaluating the distance limitations introduced

  6. An analysis of the NMR-CT image by the measurement of proton-relaxation times in tissue

    International Nuclear Information System (INIS)

    Naruse, Shoji; Horikawa, Yoshiharu; Tanaka, Chuzo; Hirakawa, Kimiyoshi; Nishikawa, Hiroyasu; Shimizu, Koji; Kiri, Motosada.

    1984-01-01

    NMR-CT images were analyzed by measuring the proton-relaxation times in tissues. The NMR-CT images were obtained in 10 normal volunteers and 16 patients with brain tumors with a prototype superconducting magnet (Shimadzu Corp., Japan) operating at 0.2 T and 0.375 T. A smooth T 1 relaxation curve was obtained in each part of the brain and the brain tumor by the use of the data of the NMR-CT image; consequently, the in vivo T 1 value was proved to be reliable. The in vivo T 1 value showed the specific value corresponding to each region of the normal brain in all cases. Cerebral gray matter normally had the longest T 1 value, followed by the medulla oblongata, the pons, and white matter. The T 1 value of each region of the brain varied to the same degree in proportion to the strength of the static magnetic field. The in vivo T 1 values of the brain tumor varied with the histological type. All were longer than any part of the brain parenchyma, being between 480 and 780 msec at 0.2 T. The prolongation of the T 1 value does not always correspond to the degree of the malignancy in a tumor. The in vitro T 1 and T 2 values were also prolonged in all tumors. Although the absolute value of T 1 did not coincide between the in vitro and in vivo data, the tendency of the prolongation was the same between them. This result indicated that the NMR-CT images could be analysed by the use of the data of the in vitro T 1 and T 2 values in the tumor tissues. It is important to analyse the NMR-CT image by both in vivo and in vitro examinations of the relaxation times. (J.P.N.)

  7. Magic angle spinning NMR below 6 K with a computational fluid dynamics analysis of fluid flow and temperature gradients

    Science.gov (United States)

    Sesti, Erika L.; Alaniva, Nicholas; Rand, Peter W.; Choi, Eric J.; Albert, Brice J.; Saliba, Edward P.; Scott, Faith J.; Barnes, Alexander B.

    2018-01-01

    We report magic angle spinning (MAS) up to 8.5 kHz with a sample temperature below 6 K using liquid helium as a variable temperature fluid. Cross polarization 13C NMR spectra exhibit exquisite sensitivity with a single transient. Remarkably, 1H saturation recovery experiments show a 1H T1 of 21 s with MAS below 6 K in the presence of trityl radicals in a glassy matrix. Leveraging the thermal spin polarization available at 4.2 K versus 298 K should result in 71 times higher signal intensity. Taking the 1H longitudinal relaxation into account, signal averaging times are therefore predicted to be expedited by a factor of >500. Computer assisted design (CAD) and finite element analysis were employed in both the design and diagnostic stages of this cryogenic MAS technology development. Computational fluid dynamics (CFD) models describing temperature gradients and fluid flow are presented. The CFD models bearing and drive gas maintained at 100 K, while a colder helium variable temperature fluid stream cools the center of a zirconia rotor. Results from the CFD were used to optimize the helium exhaust path and determine the sample temperature. This novel cryogenic experimental platform will be integrated with pulsed dynamic nuclear polarization and electron decoupling to interrogate biomolecular structure within intact human cells.

  8. 1H NMR spectroscopic analysis detects metabolic disturbances in rat urine on acute exposure to heavy metal tungsten alloy based metals salt.

    Science.gov (United States)

    Tyagi, Ritu; Rana, Poonam; Gupta, Mamta; Bhatnagar, Deepak; Srivastava, Shatakshi; Roy, Raja; Khushu, Subash

    2014-03-25

    Heavy metal tungsten alloys (HMTAs) have been found to be safer alternatives for making military munitions. Recently, some studies demonstrating the toxic potential of HMTAs have raised concern over the safety issues, and further propose that HMTAs exposure may lead to physiological disturbances as well. To look for the systemic effect of acute toxicity of HMTA based metals salt, (1)H nuclear magnetic resonance ((1)H NMR) spectroscopic profiling of rat urine was carried out. Male Sprague Dawley rats were administered (intraperitoneal) low and high dose of mixture of HMTA based metals salt and NMR spectroscopy was carried out in urine samples collected at 8, 24, 72 and 120 h post dosing (p.d.). Serum biochemical parameters and liver histopathology were also conducted. The (1)H NMR spectra were analysed using multivariate analysis techniques to show the time- and dose-dependent biochemical variations in post HMTA based metals salt exposure. Urine metabolomic analysis showed changes associated with energy metabolism, amino acids, N-methyl nicotinamide, membrane and gut flora metabolites. Multivariate analysis showed maximum variation with best classification of control and treated groups at 24h p.d. At the end of the study, for the low dose group most of the changes at metabolite level reverted to control except for the energy metabolites; whereas, in the high dose group some of the changes still persisted. The observations were well correlated with histopathological and serum biochemical parameters. Further, metabolic pathway analysis clarified that amongst all the metabolic pathways analysed, tricarboxylic acid cycle was most affected at all the time points indicating a switchover in energy metabolism from aerobic to anaerobic. These results suggest that exposure of rats to acute doses of HMTA based metals salt disrupts physiological metabolism with moderate injury to the liver, which might indirectly result from heavy metals induced oxidative stress. Copyright

  9. Hetero Diels-Alder Reaction with Aqueous Glyoxylic Acid: An Experiment in Organic Synthesis and 2-D NMR Analysis for Advanced Undergraduate Students

    Science.gov (United States)

    Augé, Jacques; Lubin-Germain, Nadège

    1998-10-01

    As an application of the use of water as solvent in organic synthesis, a convenient synthesis of a-hydroxy-g-lactones from an aqueous solution of glyoxylic acid is described. The mechanism of the reaction leading to the lactones goes through cycloadducts which rearrange in situ. The NMR analysis of the diastereomeric lactones is particularly interesting; such an analysis illustrates the importance of modern techniques including 2-D NMR spectroscopy. Complete assignments of the signals are mentioned and NOESY spectra are enclosed. The full experiment is addressed to advanced undergraduate students who are trained in organic synthesis and NMR spectroscopy.

  10. Apparatus for preparing a solution of a hyperpolarized noble gas for NMR and MRI analysis

    Science.gov (United States)

    Pines, Alexander [Berkeley, CA; Budinger, Thomas [Berkeley, CA; Navon, Gil [Ramat Gan, IL; Song, Yi-Qiao [Berkeley, CA; Appelt, Stephan [Waiblingen, DE; Bifone, Angelo [Rome, IT; Taylor, Rebecca [Berkeley, CA; Goodson, Boyd [Berkeley, CA; Seydoux, Roberto [Berkeley, CA; Room, Toomas [Albany, CA; Pietrass, Tanja [Socorro, NM

    2008-06-10

    The present invention relates generally to nuclear magnetic resonance (NMR) techniques for both spectroscopy and imaging. More particularly, the present invention relates to methods in which hyperpolarized noble gases (e.g., Xe and He) are used to enhance and improve NMR and MRI. Additionally, the hyperpolarized gas solutions of the invention are useful both in vitro and in vivo to study the dynamics or structure of a system. When used with biological systems, either in vivo or in vitro, it is within the scope of the invention to target the hyperpolarized gas and deliver it to specific regions within the system.

  11. Merremoside D: de novo synthesis of the purported structure, NMR analysis, and comparison of spectral data.

    Science.gov (United States)

    Sharif, Ehesan U; Wang, Hua-Yu Leo; Akhmedov, Novruz G; O'Doherty, George A

    2014-01-17

    The first synthesis of the purported structure of Merremoside D has been achieved in 22 longest linear steps. The de novo asymmetric synthesis relied on the use of asymmetric catalysis to selectively install all 21 stereocenters in the final compounds from commercially available achiral starting materials. Adiabatic gradient 2D NMR techniques (gHSQCAD, gHMBCAD, gH2BCAD, gHSQCTOXYAD, ROESYAD) were used to completely assign the structure of synthetic Merremoside D. Comparison of our assignments with the limited NMR data reported for natural Merremoside D allows for the tentative confirmation of its structure.

  12. 13C solid-state NMR chemical shift anisotropy analysis of the anomeric carbon in carbohydrates.

    Science.gov (United States)

    Chen, Ying-Ying; Luo, Shun-Yuan; Hung, Shang-Cheng; Chan, Sunney I; Tzou, Der-Lii M

    2005-03-21

    (13)C NMR solid-state structural analysis of the anomeric center in carbohydrates was performed on six monosaccharides: glucose (Glc), mannose (Man), galactose (Gal), galactosamine hydrochloride (GalN), glucosamine hydrochloride (GlcN), and N-acetyl-glucosamine (GlcNAc). In the 1D (13)C cross-polarization/magic-angle spinning (CP/MAS) spectrum, the anomeric center C-1 of these carbohydrates revealed two well resolved resonances shifted by 3-5ppm, which were readily assigned to the anomeric alpha and beta forms. From this experiment, we also extracted the (13)C chemical shift anisotropy (CSA) tensor elements of the two forms from their spinning sideband intensities, respectively. It was found out that the chemical shift tensor for the alpha anomer was more axially symmetrical than that of the beta form. A strong linear correlation was obtained when the ratio of the axial asymmetry of the (13)C chemical shift tensors of the two anomeric forms was plotted in a semilogarithmic plot against the relative population of the two anomers. Finally, we applied REDOR spectroscopy to discern whether or not there were any differences in the sugar ring conformation between the anomers. Identical two-bond distances of 2.57A (2.48A) were deduced for both the alpha and beta forms in GlcNAc (GlcN), suggesting that the two anomers have essentially identical sugar ring scaffolds in these sugars. In light of these REDOR distance measurements and the strong correlation observed between the ratio of the axial asymmetry parameters of the (13)C chemical shift tensors and the relative population between the two anomeric forms, we concluded that the anomeric effect arises principally from interaction of the electron charge clouds between the C-1-O-5 and the C-1-O-1 bonds in these monosaccharides.

  13. Si-O-Si bond-angle distribution in vitreous silica from first-principles 29Si NMR analysis

    International Nuclear Information System (INIS)

    Mauri, Francesco; Pasquarello, Alfredo; Pfrommer, Bernd G.; Yoon, Young-Gui; Louie, Steven G.

    2000-01-01

    The correlation between 29 Si chemical shifts and Si-O-Si bond angles in SiO 2 is determined within density-functional theory for the full range of angles present in vitreous silica. This relation closely reproduces measured shifts of crystalline polymorphs. The knowledge of the correlation allows us to reliably extract from the experimental NMR spectrum the mean (151 degree sign ) and the standard deviation (11 degree sign ) of the Si-O-Si angular distribution of vitreous silica. In particular, we show that the Mozzi-Warren Si-O-Si angular distribution is not consistent with the NMR data. This analysis illustrates the potential of our approach for structural determinations of silicate glasses. (c) 2000 The American Physical Society

  14. The use of IRMS, (1)H NMR and chemical analysis to characterise Italian and imported Tunisian olive oils.

    Science.gov (United States)

    Camin, Federica; Pavone, Anita; Bontempo, Luana; Wehrens, Ron; Paolini, Mauro; Faberi, Angelo; Marianella, Rosa Maria; Capitani, Donatella; Vista, Silvia; Mannina, Luisa

    2016-04-01

    Isotope Ratio Mass Spectrometry (IRMS), (1)H Nuclear Magnetic Resonance ((1)H NMR), conventional chemical analysis and chemometric elaboration were used to assess quality and to define and confirm the geographical origin of 177 Italian PDO (Protected Denomination of Origin) olive oils and 86 samples imported from Tunisia. Italian olive oils were richer in squalene and unsaturated fatty acids, whereas Tunisian olive oils showed higher δ(18)O, δ(2)H, linoleic acid, saturated fatty acids β-sitosterol, sn-1 and 3 diglyceride values. Furthermore, all the Tunisian samples imported were of poor quality, with a K232 and/or acidity values above the limits established for extra virgin olive oils. By combining isotopic composition with (1)H NMR data using a multivariate statistical approach, a statistical model able to discriminate olive oil from Italy and those imported from Tunisia was obtained, with an optimal differentiation ability arriving at around 98%. Copyright © 2015 Elsevier Ltd. All rights reserved.

  15. Quali- and quantitative analysis of commercial coffee by NMR; Analises quali- e quantitativa de cafes comerciais via ressonancia magnetica nuclear

    Energy Technology Data Exchange (ETDEWEB)

    Tavares, Leila Aley; Ferreira, Antonio Gilberto [Sao Carlos Univ., SP (Brazil). Dept. de Quimica]. E-mail: giba_04@yahoo.com.br

    2006-09-15

    Coffee is one of the beverages most widely consumed in the world and the 'cafezinho' is normally prepared from a blend of roasted powder of two species, Coffea arabica and Coffea canephora. Each one exhibits differences in their taste and in the chemical composition, especially in the caffeine percentage. There are several procedures proposed in the literature for caffeine determination in different samples like soft drinks, coffee, medicines, etc but most of them need a sample workup which involves at least one step of purification. This work describes the quantitative analysis of caffeine using {sup 1}H NMR and the identification of the major components in commercial coffee samples using 1D and 2D NMR techniques without any sample pre-treatment. (author)

  16. ¹H-NMR Profiling and Chemometric Analysis of Selected Honeys from South Africa, Zambia, and Slovakia.

    Science.gov (United States)

    Olawode, Emmanuel O; Tandlich, Roman; Cambray, Garth

    2018-03-05

    Honey is the natural sweet substance produced by honeybee from nectar or honeydew, exhibiting several nutritional and health benefits. It contains a complex mixture of compounds in different proportions, with sugars being the main component. The physicochemical characteristics of ten honeys were evaluated; represented by five, three, and two from South Africa, Slovakia, and Zambia, respectively. The range of values for the pH (3.75-4.38), electrical conductivity (99-659 µS/cm), and moisture content (14.2-17.7%) are within the recommended limits for quality honeys. ¹H-NMR (Nuclear Magnetic Resonance) profiling of the honeys in D₂O was determined, and the data were analysed by chemometrics. This method is fast, reproducible, and sample pre-treatment is not necessary. The ¹H-NMR fingerprints of various chemical shift regions showed similarity or dissimilarity across geographical origins that are useful for identification, detection of adulteration, and quality control. The principal component analysis PCA and partial linear square discriminant analysis PLS-DA of the ¹H-NMR profiles successively categorises the honeys into two chemically related groups. The R² values are higher than the corresponding Q² values for all samples, confirming the reliability of the model. Honeys in the same cluster contain similar metabolites and belong to the same botanic or floral origin.

  17. Analysis of NMR shifts and spin-spin coupling constants in L-Alanyl-LAlanine zwitterion

    Czech Academy of Sciences Publication Activity Database

    Sychrovský, Vladimír; Špirko, Vladimír; Šebestík, Jaroslav; Kapitán, Josef; Buděšínský, Miloš; Bouř, Petr

    2005-01-01

    Roč. 59, 7/8 (2005), s. 453 ISSN 0009-4293. [International Conference on the Applications of Density Functional Theory in Chemistry and Physics /11./. 11.09.2005-15.09.2005, Geneva] Institutional research plan: CEZ:AV0Z40550506 Keywords : NMR shifts * spin-spin coupling Subject RIV: CF - Physical ; Theoretical Chemistry

  18. Catalytic analysis of APOBEC3G involving real-time NMR spectroscopy reveals nucleic acid determinants for deamination.

    Directory of Open Access Journals (Sweden)

    Keisuke Kamba

    Full Text Available APOBEC3G (A3G is a single-stranded DNA-specific cytidine deaminase that preferentially converts cytidine to uridine at the third position of triplet cytosine (CCC hotspots. A3G restricts the infectivity of viruses, such as HIV-1, by targeting CCC hotspots scattered through minus DNA strands, reverse-transcribed from genomic RNA. Previously, we developed a real-time NMR method and elucidated the origin of the 3'→5' polarity of deamination of DNA by the C-terminal domain of A3G (CD2, which is a phenomenon by which a hotspot located closer to the 5'-end is deaminated more effectively than one less close to the 5'-end, through quantitative analysis involving nonspecific binding to and sliding along DNA. In the present study we applied the real-time NMR method to analyze the catalytic activity of CD2 toward DNA oligonucleotides containing a nucleotide analog at a single or multiple positions. Analyses revealed the importance of the sugar and base moieties throughout the consecutive 5 nucleotides, the CCC hotspot being positioned at the center. It was also shown that the sugar or base moieties of the nucleotides outside this 5 nucleotide recognition sequence are also relevant as to CD2's activity. Analyses involving DNA oligonucleotides having two CCC hotspots linked by a long sequence of either deoxyribonucleotides, ribonucleotides or abasic deoxyribonucleotides suggested that the phosphate backbone is required for CD2 to slide along the DNA strand and to exert the 3'→5' polarity. Examination of the effects of different salt concentrations on the 3'→5' polarity indicated that the higher the salt concentration, the less prominent the 3'→5' polarity. This is most likely the result of alleviation of sliding due to a decrease in the affinity of CD2 with the phosphate backbone at high salt concentrations. We also investigated the reactivity of substrates containing 5-methylcytidine (5mC or 5-hydroxymethylcytidine, and found that A3G exhibited low

  19. Analysis of Benchmark 2 results

    International Nuclear Information System (INIS)

    Bacha, F.; Lefievre, B.; Maillard, J.; Silva, J.

    1994-01-01

    The code GEANT315 has been compared to different codes in two benchmarks. We analyze its performances through our results, especially in the thick target case. In spite of gaps in nucleus-nucleus interaction theories at intermediate energies, benchmarks allow possible improvements of physical models used in our codes. Thereafter, a scheme of radioactive waste burning system is studied. (authors). 4 refs., 7 figs., 1 tab

  20. Quality assessment of Polygonum cuspidatum and Polygonum multiflorum by 1H NMR metabolite fingerprinting and profiling analysis.

    Science.gov (United States)

    Frédérich, Michel; Wauters, Jean-Noël; Tits, Monique; Jason, Charlotte; de Tullio, Pascal; Van der Heyden, Yvan; Fan, Guorong; Angenot, Luc

    2011-01-01

    The quality assessment and control of traditional Chinese medicines (TCM) nowadays receives a great deal of attention worldwide and particularly in Europe with its increasing local use. Polygonum cuspidatum Siebold & Zucc. and Polygonum multiflorum Thunb. are two members of the Polygonaceae family, which are widely used as Chinese medicinal plants. The aim of this study was to achieve an overview of the quality of P. cuspidatum and P. multiflorum samples available on the Chinese market and to identify important metabolites for their discrimination, using (1)H NMR-based metabolomics. (1)H NMR and multivariate analysis techniques were applied to almost 60 plant samples collected in different places in China. Using (1)H NMR metabolomics, it was possible, without previous evaporation or separation steps, to obtain metabolic fingerprints to distinguish between the species. The important metabolites for discrimination were stilbene derivatives. Finally, a clear distinction between the two species was possible and the discriminant metabolites were identified. © Georg Thieme Verlag KG Stuttgart · New York.

  1. NMR-based Metabolomics Analysis of Liver from C57BL/6 Mouse Exposed to Ionizing Radiation

    Energy Technology Data Exchange (ETDEWEB)

    Xiao, Xiongjie [Pacific Northwest National Laboratory, Richland, Washington 99352; State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, National Center for Magnetic Resonance in Wuhan, Wuhan Institute of Physics and Mathematics, the Chinese Academy of Sciences, Wuhan, 430071, PR China; University of Chinese Academy of Sciences, Beijing 100049, China; Hu, Mary [Pacific Northwest National Laboratory, Richland, Washington 99352; Zhang, Xu [State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, National Center for Magnetic Resonance in Wuhan, Wuhan Institute of Physics and Mathematics, the Chinese Academy of Sciences, Wuhan, 430071, PR China; Hu, Jian Zhi [Pacific Northwest National Laboratory, Richland, Washington 99352

    2017-07-01

    The health effects of exposing to ionizing radiation are attracting great interest in the space exploration community and patients considering radiotherapy. However, the impact to metabolism after exposure to high dose radiation has not yet been clearly defined in livers. In the present study, 1H nuclear magnetic resonance (NMR) based metabolomics combined with multivariate data analysis are applied to study the changes of metabolism in the liver of C57BL/6 mouse after whole body exposure to either gamma (3.0 and 7.8 Gy) or proton (3.0 Gy) radiation. Principal component analysis (PCA) and orthogonal projection to latent structures analysis (OPLS) are employed for classification and identification of potential biomarkers associated with gamma and proton irradiation. The results show that the radiation exposed groups can be well separated from the control group. At the same radiation dosage, the group exposed to proton radiation is well separated from the group exposed to gamma radiation, indicating different radiation sources induce different alterations based on metabolic profiling. Common to both gamma and proton radiation at the high radiation doses studied in this work, compared with the control groups the concentrations of choline, O-phosphocholine and trimethylamine N-oxide are decreased statistically, while those of glutamine, glutathione, malate, creatinine, phosphate, betaine and 4-hydroxyphenylacetate are statistically and significantly elevated after exposure to radiation. Since these altered metabolites are associated with multiple biological pathways, the changes suggest that the exposure to radiation induce abnormality in multiple biological pathways. In particular, metabolites such as 4-hydroxyphenylacetate, betaine, glutamine, choline and trimethylamine N-oxide may be good candidates of pre-diagnose biomarkers for ionizing radiation in liver.

  2. Functional group analysis by H NMR/chemical derivatization for the characterization of organic aerosol from the SMOCC field campaign

    Directory of Open Access Journals (Sweden)

    E. Tagliavini

    2006-01-01

    Full Text Available Water soluble organic compounds (WSOC in aerosol samples collected in the Amazon Basin in a period encompassing the middle/late dry season and the beginning of the wet season, were investigated by H NMR spectroscopy. HiVol filter samples (PM2.5 and PM>2.5 and size-segregated samples from multistage impactor were subjected to H NMR characterization. The H NMR methodology, recently developed for the analysis of organic aerosol samples, has been improved by exploiting chemical methylation of carboxylic groups with diazomethane, which allows the direct determination of the carboxylic acid content of WSOC. The content of carboxylic carbons for the different periods and sizes ranged from 12% to 20% of total measured carbon depending on the season and aerosol size, with higher contents for the fine particles in the transition and wet periods with respect to the dry period. A comprehensive picture is presented of WSOC functional groups in aerosol samples representative of the biomass burning period, as well as of transition and semi-clean atmospheric conditions. A difference in composition between fine (PM2.5 and coarse (PM>2.5 size fractions emerged from the NMR data, the former showing higher alkylic content, the latter being largely dominated by R-O-H (or R-O-R' functional groups. Very small particles (<0.14 μm, however, present higher alkyl-chain content and less oxygenated carbons than larger fine particles (0.42–1.2 μm. More limited variations were found between the average compositions in the different periods of the campaign.

  3. Mathematical Development and Computational Analysis of Harmonic Phase-Magnetic Resonance Imaging (HARP-MRI) Based on Bloch Nuclear Magnetic Resonance (NMR) Diffusion Model for Myocardial Motion.

    Science.gov (United States)

    Dada, Michael O; Jayeoba, Babatunde; Awojoyogbe, Bamidele O; Uno, Uno E; Awe, Oluseyi E

    2017-09-13

    Harmonic Phase-Magnetic Resonance Imaging (HARP-MRI) is a tagged image analysis method that can measure myocardial motion and strain in near real-time and is considered a potential candidate to make magnetic resonance tagging clinically viable. However, analytical expressions of radially tagged transverse magnetization in polar coordinates (which is required to appropriately describe the shape of the heart) have not been explored because the physics required to directly connect myocardial deformation of tagged Nuclear Magnetic Resonance (NMR) transverse magnetization in polar geometry and the appropriate harmonic phase parameters are not yet available. The analytical solution of Bloch NMR diffusion equation in spherical geometry with appropriate spherical wave tagging function is important for proper analysis and monitoring of heart systolic and diastolic deformation with relevant boundary conditions. In this study, we applied Harmonic Phase MRI method to compute the difference between tagged and untagged NMR transverse magnetization based on the Bloch NMR diffusion equation and obtained radial wave tagging function for analysis of myocardial motion. The analytical solution of the Bloch NMR equations and the computational simulation of myocardial motion as developed in this study are intended to significantly improve healthcare for accurate diagnosis, prognosis and treatment of cardiovascular related deceases at the lowest cost because MRI scan is still one of the most expensive anywhere. The analysis is fundamental and significant because all Magnetic Resonance Imaging techniques are based on the Bloch NMR flow equations.

  4. An instrument control and data analysis program for NMR imaging and spectroscopy

    International Nuclear Information System (INIS)

    Roos, M.S.; Mushlin, R.A.; Veklerov, E.; Port, J.D.; Ladd, C.; Harrison, C.G.

    1988-01-01

    We describe a software environment created to support real-time instrument control and signal acquisition as well as array-processor based signal and image processing in up to five dimensions. The environment is configured for NMR imaging and in vivo spectroscopy. It is designed to provide flexible tools for implementing novel NMR experiments in the research laboratory. Data acquisition and processing operations are programmed in macros which are loaded in assembled from to minimize instruction overhead. Data arrays are dynamically allocated for efficient use of memory and can be mapped directly into disk files. The command set includes primitives for real-time control of data acquisition, scalar arithmetic, string manipulation, branching, a file system and vector operations carried out by an array processor. 6 figs

  5. Quantitative analysis of euglobals in Eucalyptus loxophleba leaves by qNMR.

    Science.gov (United States)

    Sidana, Jasmeen; Foley, William J; Singh, Inder Pal

    2011-09-01

    A simple, rapid, accurate and selective 1H NMR spectroscopic method to detect and quantify euglobals in the leaves of Eucalyptus loxophleba ssp. lissophloia has been developed. The method allows for the estimation of total concentration of diformylphloroglucinol-monoterpene adducts, as well as the quantitation of sabinene- and alpha/beta-phellandrene-adducts, separately. The method was validated for accuracy, precision and linearity using as reference standards 2-ethyl phenol and mixtures of jensenone, a monomeric formylated phloroglucinol, and 2-ethyl phenol.

  6. Conformational analysis, spectroscopic study (FT-IR, FT-Raman, UV, 1H and 13C NMR), molecular orbital energy and NLO properties of 5-iodosalicylic acid.

    Science.gov (United States)

    Karaca, Caglar; Atac, Ahmet; Karabacak, Mehmet

    2015-02-05

    In this study, 5-iodosalicylic acid (5-ISA, C7H5IO3) is structurally characterized by FT-IR, FT-Raman, NMR and UV spectroscopies. There are eight conformers, Cn, n=1-8 for this molecule therefore the molecular geometry for these eight conformers in the ground state are calculated by using the ab-initio density functional theory (DFT) B3LYP method approach with the aug-cc-pVDZ-PP basis set for iodine and the aug-cc-pVDZ basis set for the other elements. The computational results identified that the most stable conformer of 5-ISA is the C1 form. The vibrational spectra are calculated DFT method invoking the same basis sets and fundamental vibrations are assigned on the basis of the total energy distribution (TED) of the vibrational modes, calculated with scaled quantum mechanics (SQM) method with PQS program. Total density of state (TDOS) and partial density of state (PDOS) and also overlap population density of state (COOP or OPDOS) diagrams analysis for C1 conformer were calculated using the same method. The energy and oscillator strength are calculated by time-dependent density functional theory (TD-DFT) results complement with the experimental findings. Besides, charge transfer occurring in the molecule between HOMO and LUMO energies, frontier energy gap, molecular electrostatic potential (MEP) are calculated and presented. The NMR chemical shifts ((1)H and (13)C) spectra are recorded and calculated using the gauge independent atomic orbital (GIAO) method. Mulliken atomic charges of the title molecule are also calculated, interpreted and compared with salicylic acid. The optimized bond lengths, bond angles and calculated NMR and UV, vibrational wavenumbers showed the best agreement with the experimental results. Copyright © 2014 Elsevier B.V. All rights reserved.

  7. Analysis of trivalent cation complexation to functionalized mesoporous silica using solid-state NMR spectroscopy.

    Science.gov (United States)

    Shusterman, Jennifer; Mason, Harris; Bruchet, Anthony; Zavarin, Mavrik; Kersting, Annie B; Nitsche, Heino

    2014-11-28

    Functionalized mesoporous silica has applications in separations science, catalysis, and sensors. In this work, we studied the fundamental interactions of trivalent cations with functionalized mesoporous silica. We contacted trivalent cations of varying ionic radii with N-[5-(trimethoxysilyl)-2-aza-1-oxopentyl]caprolactam functionalized mesoporous silica with the aim of probing the binding mechanism of the metal to the surface of the solid. We studied the functionalized silica using solid-state nuclear magnetic resonance (NMR) spectroscopy before and after contact with the metals of interest. We collected NMR spectra of the various metals, as well as of (29)Si and (13)C to probe the silica substrate and the ligand properties, respectively. The NMR spectra indicate that the metals bind to the functionalized silica via two mechanisms. Aluminum sorbed to both the silica and the ligand, but with different coordination for each. Scandium also sorbed to both the silica and the ligand, and unlike the aluminum, had the same coordination number. Additionally, the functionalized silica was susceptible to acid hydrolysis and two primary mechanisms of degradation were observed: detachment from the silica surface and opening of the seven-membered ring in the ligand. Opening of the seven-membered ring may be beneficial in that it decreases steric hindrance of the molecule for binding.

  8. Rapid prediction of multi-dimensional NMR data sets

    International Nuclear Information System (INIS)

    Gradmann, Sabine; Ader, Christian; Heinrich, Ines; Nand, Deepak; Dittmann, Marc; Cukkemane, Abhishek; Dijk, Marc van; Bonvin, Alexandre M. J. J.; Engelhard, Martin; Baldus, Marc

    2012-01-01

    We present a computational environment for Fast Analysis of multidimensional NMR DAta Sets (FANDAS) that allows assembling multidimensional data sets from a variety of input parameters and facilitates comparing and modifying such “in silico” data sets during the various stages of the NMR data analysis. The input parameters can vary from (partial) NMR assignments directly obtained from experiments to values retrieved from in silico prediction programs. The resulting predicted data sets enable a rapid evaluation of sample labeling in light of spectral resolution and structural content, using standard NMR software such as Sparky. In addition, direct comparison to experimental data sets can be used to validate NMR assignments, distinguish different molecular components, refine structural models or other parameters derived from NMR data. The method is demonstrated in the context of solid-state NMR data obtained for the cyclic nucleotide binding domain of a bacterial cyclic nucleotide-gated channel and on membrane-embedded sensory rhodopsin II. FANDAS is freely available as web portal under WeNMR (http://www.wenmr.eu/services/FANDAShttp://www.wenmr.eu/services/FANDAS).

  9. Ratiometric analysis in hyperpolarized NMR (I): test of the two-site exchange model and the quantification of reaction rate constants.

    Science.gov (United States)

    Li, Lin Z; Kadlececk, Stephen; Xu, He N; Daye, Dania; Pullinger, Benjamin; Profka, Harrilla; Chodosh, Lewis; Rizi, Rahim

    2013-10-01

    Conventional methods for the analysis of in vivo hyperpolarized (13) C NMR data from the lactate dehydrogenase (LDH) reaction usually make assumptions on the stability of rate constants and/or the validity of the two-site exchange model. In this study, we developed a framework to test the validity of the assumption of stable reaction rate constants and the two-site exchange model in vivo via ratiometric fitting of the time courses of the signal ratio L(t)/P(t). Our analysis provided evidence that the LDH enzymatic kinetics observed by hyperpolarized NMR are in near-equilibrium and satisfy the two-site exchange model for only a specific time window. In addition, we quantified both the forward and reverse exchange rate constants of the LDH reaction for the transgenic and mouse xenograft models of breast cancer using the ratio fitting method developed, which includes only two modeling parameters and is less sensitive to the influence of instrument settings/protocols, such as flip angles, degree of polarization and tracer dosage. We further compared the ratio fitting method with a conventional two-site exchange modeling method, i.e. the differential equation fitting method, using both the experimental and simulated hyperpolarized NMR data. The ratio fitting method appeared to fit better than the differential equation fitting method for the reverse rate constant on the mouse tumor data, with less relative errors on average, whereas the differential equation fitting method also resulted in a negative reverse rate constant for one tumor. The simulation results indicated that the accuracy of both methods depends on the width of the transport function, noise level and rate constant ratio; one method may be more accurate than the other based on the experimental/biological conditions aforementioned. We were able to categorize our tumor models into specific conditions of the computer simulation and to estimate the errors of rate quantification. We also discussed possible

  10. Analysis of dehydration kinetics, status of water and oil distribution of microwave-assisted vacuum frying potato chips combined with NMR and confocal laser scanning microscopy.

    Science.gov (United States)

    Su, Ya; Zhang, Min; Fang, Zhongxiang; Zhang, Weiming

    2017-11-01

    In this study, the dehydration kinetics, status of water and oil distribution of microwave-assisted vacuum frying (MVF) potato chips were analyzed combining with NMR and confocal laser scanning microscopy (CLSM). Results showed that the MVF markedly increased the moisture evaporation kinetics and effective moisture diffusivity compared to vacuum frying (VF). The higher microwave power level (1000W) used achieved higher moisture evaporation rate and higher effective moisture diffusivity, The Logarithmic model exhibited the best fit for the obtained data of MR versus frying time in the MVF. The NMR analysis showed the free water in the samples firstly evaporate and the linkage between water and structure of materials becomes tighter with the frying time. The total oil content, surface and structural oil content were all significantly lower in MVF samples than that in VF samples. The CLSM analysis confirmed that less oil adhere to the surface and less oil trapped in the structure in MVF slices. The surface morphology showed that there were less ruptured and damaged cells in MVF samples and helped to explain the reduction of oil content. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. NBO, HOMO-LUMO, UV, NLO, NMR and vibrational analysis of veratrole using FT-IR, FT-Raman, FT-NMR spectra and HF-DFT computational methods.

    Science.gov (United States)

    Suvitha, A; Periandy, S; Gayathri, P

    2015-03-05

    This work deals with FT-IR, FT-Raman and FT-NMR spectral analysis and NBO, NLO, HOMO-LUMO and electronic transitions studies on veratrole. The molecular structure, fundamental vibrational frequencies and intensity of the vibrational bands were interpreted with the aid of structure optimizations and geometrical parameter calculations based on Hartree-Fock (HF) and density functional theory (DFT) method with 6-311++G(d, p) basis set. A study on the electronic properties, such as HOMO and LUMO energies were performed by time independent DFT approach. In addition, molecular electrostatic potential (MEP), Natural Bond-Orbital (NBO) analysis and thermodynamic properties were performed. The (1)H and (13)C nuclear magnetic resonance (NMR) chemical shifts of the molecule were calculated by gauge independent atomic orbital (GIAO) method and compared with experimental chemical shift. Copyright © 2014 Elsevier B.V. All rights reserved.

  12. Elucidating an Amorphous Form Stabilization Mechanism for Tenapanor Hydrochloride: Crystal Structure Analysis Using X-ray Diffraction, NMR Crystallography, and Molecular Modeling.

    Science.gov (United States)

    Nilsson Lill, Sten O; Widdifield, Cory M; Pettersen, Anna; Svensk Ankarberg, Anna; Lindkvist, Maria; Aldred, Peter; Gracin, Sandra; Shankland, Norman; Shankland, Kenneth; Schantz, Staffan; Emsley, Lyndon

    2018-03-12

    By the combined use of powder and single-crystal X-ray diffraction, solid-state NMR, and molecular modeling, the crystal structures of two systems containing the unusually large tenapanor drug molecule have been determined: the free form, ANHY, and a dihydrochloride salt form, 2HCl. Dynamic nuclear polarization (DNP) assisted solid-state NMR (SSNMR) crystallography investigations were found essential for the final assignment and were used to validate the crystal structure of ANHY. From a structural informatics analysis of ANHY and 2HCl, conformational ring differences in one part of the molecule were observed which influence the relative orientation of a methyl group on a ring nitrogen and thereby impact the crystallizability of the dihydrochloride salt. From quantum chemistry calculations, the dynamics between different ring conformations in tenapanor is predicted to be fast. Addition of HCl to tenapanor results in general in a mixture of protonated ring conformers and hence a statistical mix of diastereoisomers which builds up the amorphous form, a-2HCl. This was qualitatively verified by 13 C CP/MAS NMR investigations of the amorphous form. Thus, to form any significant amount of the crystalline material 2HCl, which originates from the minor (i.e., energetically less stable) ring conformations, one needs to involve nitrogen deprotonation to allow exchange between the minor and major conformations of ANHY in solution. Thus, by controlling the solution pH value to well below the p K a of ANHY, the equilibrium between ANHY and 2HCl can be controlled and by this mechanism the crystallization of 2HCl can be avoided and the amorphous form of the dichloride salt can therefore be stabilized.

  13. Solid-state NMR analysis of membrane proteins and protein aggregates by proton detected spectroscopy

    International Nuclear Information System (INIS)

    Zhou, Donghua H.; Nieuwkoop, Andrew J.; Berthold, Deborah A.; Comellas, Gemma; Sperling, Lindsay J.; Tang, Ming; Shah, Gautam J.; Brea, Elliott J.; Lemkau, Luisel R.; Rienstra, Chad M.

    2012-01-01

    Solid-state NMR has emerged as an important tool for structural biology and chemistry, capable of solving atomic-resolution structures for proteins in membrane-bound and aggregated states. Proton detection methods have been recently realized under fast magic-angle spinning conditions, providing large sensitivity enhancements for efficient examination of uniformly labeled proteins. The first and often most challenging step of protein structure determination by NMR is the site-specific resonance assignment. Here we demonstrate resonance assignments based on high-sensitivity proton-detected three-dimensional experiments for samples of different physical states, including a fully-protonated small protein (GB1, 6 kDa), a deuterated microcrystalline protein (DsbA, 21 kDa), a membrane protein (DsbB, 20 kDa) prepared in a lipid environment, and the extended core of a fibrillar protein (α-synuclein, 14 kDa). In our implementation of these experiments, including CONH, CO(CA)NH, CANH, CA(CO)NH, CBCANH, and CBCA(CO)NH, dipolar-based polarization transfer methods have been chosen for optimal efficiency for relatively high protonation levels (full protonation or 100 % amide proton), fast magic-angle spinning conditions (40 kHz) and moderate proton decoupling power levels. Each H–N pair correlates exclusively to either intra- or inter-residue carbons, but not both, to maximize spectral resolution. Experiment time can be reduced by at least a factor of 10 by using proton detection in comparison to carbon detection. These high-sensitivity experiments are especially important for membrane proteins, which often have rather low expression yield. Proton-detection based experiments are expected to play an important role in accelerating protein structure elucidation by solid-state NMR with the improved sensitivity and resolution.

  14. Analysis of Hydroperoxides in solid Polyethylene by NMR and EPR Spectroscopy

    International Nuclear Information System (INIS)

    Assink, Roger A.; Celina, Mathias C.; Dunbar, Timothy D.; Alam, Todd M.; Clough, Roger Lee; Gillen, Kenneth T.

    2000-01-01

    The authors have shown that the hydroperoxide species in γ-irradiated 13 C-polyethylene can be directly observed by 13 C MAS NMR spectroscopy. The experiment was performed without the need for special sample preparation such as chemical derivatization or dissolution. Annealing experiments were employed to study the thermal decomposition of the hydroperoxide species and to measure an activation energy of 98 kJ/mol. EPR spectroscopy suggests that residual polyenyl and alkylperoxy radicals are predominantly trapped in interracial or crystalline regions, while the peroxy radicals observed after UV-photolysis of hydroperoxides are in amorphous regions

  15. Nuclear Magnetic Resonance spectroscopy of marine microalgae: Metabolic profiling and species discrimination from High-Resolution Magic Angle Spinning NMR analysis of whole-cell samples

    OpenAIRE

    Chauton, Matilde Skogen

    2005-01-01

    Based on what is said about the background and structure, this thesis presents a discussion of the use of NMR spectroscopy as a tool for species discrimination and metabolic profiling of microalgae. The results of various analyses including NMR and statistics are evaluated from what is known from already established identification methods such as pigment chromatography and chemotaxonomy, and the chemical composition of microalgal cells. The main focus is on the application of HR MAS on whole ...

  16. FT-IR and FT-Raman, NMR and UV spectroscopic investigation and hybrid computational (HF and DFT) analysis on the molecular structure of mesitylene.

    Science.gov (United States)

    Kose, E; Atac, A; Karabacak, M; Nagabalasubramanian, P B; Asiri, A M; Periandy, S

    2013-12-01

    The spectroscopic properties of mesitylene were investigated by FT-IR, FT-Raman, UV, (1)H and (13)C NMR techniques. The geometrical parameters and energies have been obtained from density functional theory (DFT) B3LYP method and Hartree-Fock (HF) method with 6-311++G(d,p) and 6-311G(d,p) basis sets calculations. The geometry of the molecule was fully optimized, vibrational spectra were calculated and fundamental vibrations were assigned on the basis of the total energy distribution (TED) of the vibrational modes, calculated with scaled quantum mechanics (SQM) method and PQS program. Total and partial density of state (TDOS and PDOS) and also overlap population density of state (OPDOS) diagrams analysis were presented. (13)C and (1)H NMR chemical shifts were calculated by using the gauge-invariant atomic orbital (GIAO) method. The electronic properties, such as excitation energies, oscillator strength, wavelengths, HOMO and LUMO energies, were performed by time-dependent density functional theory (TD-DFT) results complements with the experimental findings. The results of the calculations were applied to simulate spectra of the title compound, which show excellent agreement with observed spectra. Besides, frontier molecular orbitals (FMO), molecular electrostatic potential (MEP) and thermodynamic properties were performed. Reduced density gradient (RDG) of the mesitylene was also given to investigate interactions of the molecule. Copyright © 2013 Elsevier B.V. All rights reserved.

  17. Increasing water solubility with decreasing droplet size limits the use of water NMR diffusometry in submicron W/O-emulsion droplet size analysis.

    Science.gov (United States)

    Balcaen, Mathieu; De Neve, Lorenz; Vermeir, Lien; Courtin, Timothee; Dewettinck, Koen; Sinnaeve, Davy; Van der Meeren, Paul

    2018-03-15

    Water droplet size analysis of water-in-oil emulsions using water NMR diffusometry yielded values that were, from a certain shear intensity onwards, independent from the shear which was used during production. It was assumed that the constant water droplet size, obtained for samples prepared at higher shear, were only apparent droplet diameters. Considering the well-known increased solubility of the dispersed phase in the continuous phase at smaller droplet sizes, it is hypothesized that water diffusion in the oil phase was responsible for the fact that apparent rather than real sizes were obtained. W/O-emulsions, prepared with a varying shear intensity, were characterized using dynamic light scattering, light microscopy, T 2 -relaxometry and PFG-NMR diffusometry. The latter measurements were conducted on both a low- and a high-resolution device and was based on either water (LR- and HR-NMR) or a water-soluble marker (HR-NMR). Low-resolution PFG-NMR is incapable of accurately determining the droplet size of W/O-emulsions containing (sub)micron sized droplets. On the other hand, using high-resolution PFG-NMR diffusometry and the addition of an oil insoluble marker to the water phase, the application window could be extended towards smaller droplet sizes. Finally, it was shown that T 2 -relaxometry was capable of detecting differences in droplet size between (sub)micron sized W/O-emulsions. Copyright © 2017 Elsevier Inc. All rights reserved.

  18. Piperamides from Piper ottonoides by NMR and GC-MS based mixture analysis

    Energy Technology Data Exchange (ETDEWEB)

    Wolff, Thiago; Valente, Ligia M.M., E-mail: valente@iq.ufrj.br [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Inst. de Química; Santos, Priscila F.P. [Centro Federal de Educação Tecnológica Celso Suckow da Fonseca (UnED/CEFET), Angra dos Reis, RJ (Brazil); Magalhães, Alvicler [Universidade Estadual de Campinas (UNICAMP), SP (Brazil). Departamento de Química Inorgânica; Tinoco, Luzineide W. [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Instituto de Pesquisa em Produtos Naturais; Pereira, Rita C.A. [Embrapa Agroindústria Tropical, Fortaleza, CE (Brazil); Guimarães, Elsie F. [Instituto de Pesquisas Jardim Botânico do Rio de Janeiro, RJ (Brazil)

    2015-07-01

    The species Piper ottonoides Yuncker (Piperaceae), known as 'joão-brandim', is a shrub that occurs in the Brazilian Amazon rainforest. Its roots and leaves are used in traditional medicine as local anesthetic to treat toothache and sore throat. In this study, the structural characterization in mixture of isobutyl amides present in semi-purified fractions from fruits, leaves, stems and roots of P. ottonoides was achieved by employing gas chromatography-mass spectrometry (GC-MS) and a combination of nuclear magnetic resonance (NMR) techniques ({sup 1}H, {sup 1}H-{sup 1}H COSY, {sup 1}H-{sup 13}CHSQC, {sup 1}H-{sup 13}CHMBC, TOCSY and {sup 1}H-{sup 1}H J-RES). The MS fragmentation patterns and the NMR chemical shifts, multiplicities, coupling constants and the signal correlations in the two-dimensional spectra were carefully analyzed also taking into account some key elements of differentiation among the compounds. The data set allowed identifying unequivocally the new amide N-isobutyl-7-(4'- methoxyphenyl)-2E,4E-heptadienamide, which we named ottonoidenamide as well as piperovatine and chingchengenamide A in all parts of the plant, the additional presence of pipercallosine and pipercallosidine in roots and of dihydropiperlonguminine in fruits and leaves. The presence of piperovatine and pipercallosine in P. ottonoides should be associated to its traditional use. (author)

  19. NMR analysis of fractionated irradiated {kappa}-carrageenan oligomers as plant growth promoter

    Energy Technology Data Exchange (ETDEWEB)

    Abad, L.V., E-mail: lvabad@pnri.dost.gov.ph [Philippine Nuclear Research Institute, Commonwealth Avenue, Diliman, Quezon City (Philippines); Saiki, S.; Nagasawa, N. [Quantum Beam Science Directorate, Japan Atomic Energy Agency, 1233 Watanuki, Takasaki, Gunma 370-1292 (Japan); Kudo, H.; Katsumura, Y. [Graduate School of Engineering, The University of Tokyo, 2-22 Shirakata-Shirane, Tokai, Naka, Ibaraki 319-1188 (Japan); De La Rosa, A.M. [Philippine Nuclear Research Institute, Commonwealth Avenue, Diliman, Quezon City (Philippines)

    2011-09-15

    The optimum plant growth promoting effect in irradiated {kappa}-carrageenan is known to be of Mw<10,000. This is obtained by irradiating {kappa}-carrageenan at a dose of 100 kGy in solid and at 2 kGy in 1% aqueous solution. Kappa carrageenan irradiated at these doses was fractionated at different Mw ranges. The isolated fraction with a Mw of 3-10 kDa was analyzed by NMR. The chemical shifts of {sup 13}C and {sup 1}H spectra indicated that the basic functional structure of {kappa}-carrageenan (alternating D-galactose-4-sulfate and 3,6-anhydro-D-galactose dimer) remains intact at a Mw of 3-10 kDa. No radiolytic products were detected at this range. - Highlights: > Irradiated {kappa}-carrageenan fractions with Mw<3 kDa contained higher carbonyl bonds. > {sup 1}H NMR and {sup 13}C spectra of irradiated {kappa}-carrageenan were similar to references. > {kappa}-Carrageenan oligomers with Mw of 3-10 kDa may be suitable as plant growth promoter.

  20. Piperamides from Piper ottonoides by NMR and GC-MS based mixture analysis

    International Nuclear Information System (INIS)

    Wolff, Thiago; Valente, Ligia M.M.; Magalhães, Alvicler; Guimarães, Elsie F.

    2015-01-01

    The species Piper ottonoides Yuncker (Piperaceae), known as 'joão-brandim', is a shrub that occurs in the Brazilian Amazon rainforest. Its roots and leaves are used in traditional medicine as local anesthetic to treat toothache and sore throat. In this study, the structural characterization in mixture of isobutyl amides present in semi-purified fractions from fruits, leaves, stems and roots of P. ottonoides was achieved by employing gas chromatography-mass spectrometry (GC-MS) and a combination of nuclear magnetic resonance (NMR) techniques ( 1 H, 1 H- 1 H COSY, 1 H- 13 CHSQC, 1 H- 13 CHMBC, TOCSY and 1 H- 1 H J-RES). The MS fragmentation patterns and the NMR chemical shifts, multiplicities, coupling constants and the signal correlations in the two-dimensional spectra were carefully analyzed also taking into account some key elements of differentiation among the compounds. The data set allowed identifying unequivocally the new amide N-isobutyl-7-(4'- methoxyphenyl)-2E,4E-heptadienamide, which we named ottonoidenamide as well as piperovatine and chingchengenamide A in all parts of the plant, the additional presence of pipercallosine and pipercallosidine in roots and of dihydropiperlonguminine in fruits and leaves. The presence of piperovatine and pipercallosine in P. ottonoides should be associated to its traditional use. (author)

  1. Discriminative Analysis of Different Grades of Gaharu (Aquilaria malaccensis Lamk. via 1H-NMR-Based Metabolomics Using PLS-DA and Random Forests Classification Models

    Directory of Open Access Journals (Sweden)

    Siti Nazirah Ismail

    2017-09-01

    Full Text Available Gaharu (agarwood, Aquilaria malaccensis Lamk. is a valuable tropical rainforest product traded internationally for its distinctive fragrance. It is not only popular as incense and in perfumery, but also favored in traditional medicine due to its sedative, carminative, cardioprotective and analgesic effects. The current study addresses the chemical differences and similarities between gaharu samples of different grades, obtained commercially, using 1H-NMR-based metabolomics. Two classification models: partial least squares-discriminant analysis (PLS-DA and Random Forests were developed to classify the gaharu samples on the basis of their chemical constituents. The gaharu samples could be reclassified into a ‘high grade’ group (samples A, B and D, characterized by high contents of kusunol, jinkohol, and 10-epi-γ-eudesmol; an ‘intermediate grade’ group (samples C, F and G, dominated by fatty acid and vanillic acid; and a ‘low grade’ group (sample E and H, which had higher contents of aquilarone derivatives and phenylethyl chromones. The results showed that 1H- NMR-based metabolomics can be a potential method to grade the quality of gaharu samples on the basis of their chemical constituents.

  2. QM/MM methodology, docking and spectroscopic (FT-IR/FT-Raman, NMR, UV) and Fukui function analysis on adrenergic agonist.

    Science.gov (United States)

    Uma Maheswari, J; Muthu, S; Sundius, Tom

    2015-02-25

    The Fourier transform infrared, FT-Raman, UV and NMR spectra of Ternelin have been recorded and analyzed. Harmonic vibrational frequencies have been investigated with the help of HF with 6-31G (d,p) and B3LYP with 6-31G (d,p) and LANL2DZ basis sets. The (1)H and (13)C nuclear magnetic resonance (NMR) chemical shifts of the molecule were calculated by GIAO method. The polarizability (α) and the first hyperpolarizability (β) values of the investigated molecule have been computed using DFT quantum mechanical calculations. Stability of the molecule arising from hyper conjugative interactions, and charge delocalization has been analyzed using natural bond orbital (NBO) analysis. The electron density-based local reactivity descriptors such as Fukui functions were calculated to explain the chemical selectivity or reactivity site in Ternelin. Finally the calculated results were compared to simulated infrared and Raman spectra of the title compound which show good agreement with observed spectra. Molecular docking studies have been carried out in the active site of Ternelin and reactivity with ONIOM was also investigated. Copyright © 2014 Elsevier B.V. All rights reserved.

  3. Classification of gilthead sea bream (Sparus aurata) from 1H NMR lipid profiling combined with principal component and linear discriminant analysis.

    Science.gov (United States)

    Rezzi, Serge; Giani, Ivan; Héberger, Károly; Axelson, David E; Moretti, Vittorio M; Reniero, Fabiano; Guillou, Claude

    2007-11-28

    The combination of (1)H NMR fingerprinting of lipids from gilthead sea bream (Sparus aurata) with nonsupervised and supervised multivariate analysis was applied to differentiate wild and farmed fish and to classify farmed specimen according to their areas of production belonging to the Mediterranean basin. Principal component analysis (PCA) applied on processed (1)H NMR profiles made a clear distinction between wild and farmed samples. Linear discriminant analysis (LDA) allowed classification of samples according to the geographic origin, as well as for the wild and farmed status using both PCA scores and NMR data as variables. Variable selection for LDA was achieved with forward selection (stepwise) with a predefined 5% error level. The methods allowed the classification of 100% of the samples according to their wild and farmed status and 85-97% to geographic origin. Probabilistic neural network (PNN) analyses provided complementary means for the successful discrimination among classes investigated.

  4. Insilico molecular modeling, docking and spectroscopic [FT-IR/FT-Raman/UV/NMR] analysis of Chlorfenson using computational calculations.

    Science.gov (United States)

    Ramalingam, S; Periandy, S; Sugunakala, S; Prabhu, T; Bououdina, M

    2013-11-01

    In the present work, the recorded FT-IR/FT-Raman spectra of the Chlorfenson (4-Chorophenyl-4-chlorobenzenesulfonate) are analysed. The observed vibrational frequencies are assigned and the computational calculations are carried out by DFT (LSDA, B3LYP and B3PW91) methods with 6-31++G(d,p) and 6-311++G(d,p) basis sets and the corresponding results are investigated with the UV/NMR data. The fluctuation of structure of Chlorobenzenesulfonate due to the substitution of C6H4Cl is investigated. The vibrational sequence pattern of the molecule related to the substitutions is intensely analysed. Moreover, (13)C NMR and (1)H NMR chemical shifts are calculated by using the gage independent atomic orbital (GIAO) technique with HF/B3LYP/B3PW91 methods on same basis set. A study on the electronic properties; absorption wavelengths, excitation energy, dipole moment and frontier molecular orbital energies, are performed by HF and DFT methods. The calculated energy of Kubo gap (HOMO and LUMO) ensures that the charge transfer occurs within the molecule. Besides frontier molecular orbitals (FMOs), molecular electrostatic potential (MEP) is executed. NLO properties and Mulliken charges of the Chlorfenson is also calculated and interpreted. Biological properties like the target receptor identification, and Identification of interacting residues, of this compound is identified and analysed by using SWISSMODEL, Castp, Hex and Pdb Sum. By using these properties, the mechanism of action of this compound on ATP Synthase of Tetranychus urticae is found and it is very much useful to develop efficient pesticides having less toxic to the environment. Crown Copyright © 2013. Published by Elsevier B.V. All rights reserved.

  5. Fundamentals of Protein NMR Spectroscopy

    CERN Document Server

    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...

  6. Determination of muscle protein synthesis rates in fish using (2)H2O and (2)H NMR analysis of alanine.

    Science.gov (United States)

    Marques, Cátia; Viegas, Filipa; Rito, João; Jones, John; Viegas, Ivan

    2016-09-15

    Following administration of deuterated water ((2)H2O), the fractional synthetic rate (FSR) of a given endogenous protein can be estimated by (2)H-enrichment quantification of its alanine residues. Currently, this is measured by mass spectrometry following a derivatization procedure. Muscle FSR was measured by (1)H/(2)H NMR analysis of alanine from seabass kept for 6 days in 5% (2)H-enriched saltwater, following acid hydrolysis and amino acid isolation by cation-exchange chromatography of muscle tissue. The analysis is simple and robust, and provides precise measurements of excess alanine (2)H-enrichment in the 0.1-0.4% range from 50 mmol of alanine recovered from muscle protein. Copyright © 2016 Elsevier Inc. All rights reserved.

  7. Complete 1H-NMR and 13C-NMR spectral analysis of the pairs of 20(S and 20(R ginsenosides

    Directory of Open Access Journals (Sweden)

    Heejung Yang

    2014-07-01

    Methods: We isolated 21 compounds, including 10 pairs of 20(S and 20(R less polar ginsenosides (1–20, and an oleanane-type triterpene (21 from a processed ginseng preparation and obtained complete 1H-NMR and 13C-NMR spectroscopic data for the following compounds, referred to as compounds 1–21 for rapid identification: 20(S-ginsenosides Rh2 (1, 20(R-Rh2 (2, 20(S-Rg3 (3, 20(R-Rg3 (4, 6′-O-acetyl-20(S-Rh2 [20(S-AcetylRh2] (5, 20(R-AcetylRh2 (6, 25-hydroxy-20(S-Rh2 (7, 25-hydroxy-20(S-Rh2 (8, 20(S-Rh1 (9, 20(R-Rh1 (10, 20(S-Rg2 (11, 20(R-Rg2 (12, 25-hydroxy-20(S-Rh1 (13, 25-hydroxy-20(R-Rh1 (14, 20(S-AcetylRg2 (15, 20(R-AcetylRg2 (16, Rh4 (17, Rg5 (18, Rk1 (19, 25-hydroxy-Rh4 (20, and oleanolic acid 28-O-β-D-glucopyranoside (21.

  8. Hyperpolarized NMR Analysis of Enzymatic Reaction: Extension of Observable Reaction Time by Deuterium Isotope Labeling

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Youngbok [Hanyang University, Ansan (Korea, Republic of)

    2016-06-15

    Affording several orders of signal enhancement compared to conventional nuclear magnetic resonance(NMR), dynamic nuclear polarization (DNP) enables direct observation of the most common {sup 13}C nuclei in organic chemistry and biochemistry at low concentrations. These nuclei have poor sensitivity due to low natural abundance and a low gyromagnetic ratio. Herein, we report an application of this technique to a multi-step enzymatic reaction. The main aim of this study was to demonstrate the effect of deuteration on specific spins of interest for the real-time trypsin hydrolysis reaction of synthesized N{sub α}-benzoyl-L-arginine methyl- d{sub 3} ester (BAME-d{sub 3}). Kinetic parameter and fit accuracy were analyzed in order to determine the in fluence of deuteration.

  9. Principal component analysis for verifying 1H NMR spectral assignments. The case of 3-aryl (1,2,4)-oxadiazole-5-carbohydrazide benzylidene

    International Nuclear Information System (INIS)

    Silva, Joao Bosco P. da; Malvestiti, Ivani; Hallwass, Fernando; Ramos, Mozart N.; Leite, Lucia F.C. da Costa; Barreiro, Eliezer J.

    2005-01-01

    The 1 H NMR data set of a series of 3-aryl (1,2,4)-oxadiazole-5-carbohydrazide benzylidene derivatives synthesized in our group was analyzed using the chemometric technique of principal component analysis (PCA). Using the original 1H NMR data PCA allowed identifying some misassignments of the proton aromatic chemical shifts. As a consequence of this multivariate analysis, nuclear Overhauser difference experiments were performed to investigate the ambiguity of other assignments of the ortho and meta aromatic hydrogens for the compound with the bromine substituent. The effect of the 1,2,4-oxadiazole group as an electron acceptor, mainly for the hydrogens 12,13, has been highlighted. (author)

  10. Urinary NMR-based metabolomic analysis of rats possessing variable sperm count following orally administered Eurycoma longifolia extracts of different quassinoid levels.

    Science.gov (United States)

    Ebrahimi, Forough; Ibrahim, Baharudin; Teh, Chin-Hoe; Murugaiyah, Vikneswaran; Chan, Kit-Lam

    2016-04-22

    Eurycoma longifolia (Tongkat Ali, TA) roots have been ethnically used as a remedy to boost male sexual desire, libido, energy and fertility. The study evaluated the effect of TA extracts with different quassinoid levels on rats sperm count and examined corresponding post-treatment urinary metabolic changes. Twenty-four male Sprague-Dawley rats, categorized into 4 groups of 6 rats each, were orally administered for 48 days with water for the control (group 1), 125mg/kg of TA water extract (TAW, group 2), 125mg/kg of TA quassinoid-poor extract (TAQP, group 3) and 21mg/kg of TA quassinoid-rich extract (TAQR, group 4). Upon completion of the 48-day treatment, the urine samples were analyzed by NMR and the animals were subsequently sacrificed for sperm count analysis. The urine profiles were categorized according to sperm count level. The results showed that the sperm count in TAW- and TAQR-treated groups was significantly higher compared to the TAQP-administered and control groups. The orthogonal partial least squares discriminant analysis (OPLS-DA) model indicated a clear separation among the urine profiles with respect to sperm count level. Urine (1)H-NMR profiles of the high-sperm count group contained higher concentrations of trigonelline, alanine, benzoic acid and higher intensity of a signal at 3.42ppm, while ethanol was at higher concentration in the normal-sperm count group. The results proved the efficacy of quassinoids on sperm count increase in rats and provided quantitative markers in urine suitable for analysis of sperm profile and male fertility status. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  11. Structural NMR assignment

    International Nuclear Information System (INIS)

    Procter, J.B.; Torda, A.E.

    1999-01-01

    Full text: General automated NMR assignment approaches are aimed at full heteronuclear assignment, which is needed for structure determination. Usually, full assignment requires at least as much spectral information as is used for structure generation. For large proteins, obtaining sufficient spectral information may require a number of sample preparations and many spectra, resulting in a significant overhead for the use of NMR in biochemical investigation. For a protein of biochemical interest one may already have an x-ray crystal structure, but spectral assignment is still needed to use NMR as a structural probe for ligand binding studies. In this situation it may be possible to use much less spectral information to make an assignment based purely on the correspondence of structural data to the measurements contained in a few simple spectra. We introduce a framework to accomplish this 'structural assignment', and give some observations on the practical requirements for a structural assignment to succeed

  12. Comparison among Different Gilthead Sea Bream (Sparus aurata Farming Systems: Activity of Intestinal and Hepatic Enzymes and 13C-NMR Analysis of Lipids

    Directory of Open Access Journals (Sweden)

    Vincenzo Zonno

    2009-12-01

    Full Text Available In order to evaluate differences in general health and nutritional values of gilthead sea bream (Sparus aurata, the effects of semi-intensive, land-based tanks and sea-cages intensive rearing systems were investigated, and results compared with captured wild fish. The physiological state was determined by measuring the activity of three different intestinal digestive enzymes: alkaline phosphatase (ALP, leucine aminopeptidase (LAP and maltase; and the activity of the hepatic ALP. Also, the hepatic content in protein, cholesterol, and lipid were assessed. 13C-NMR analysis for qualitative and quantitative characterization of the lipid fraction extracted from fish muscles for semiintensive and land based tanks intensive systems was performed. The lipid fraction composition showed small but significant differences in the monounsaturated/saturated fatty acid ratio, with the semi-intensive characterized by higher monounsaturated and lower saturated fatty acid content with respect to land based tanks intensive rearing system.

  13. Emission Properties, Solubility, Thermodynamic Analysis and NMR Studies of Rare-Earth Complexes with Two Different Phosphine Oxides

    Directory of Open Access Journals (Sweden)

    Hiroki Iwanaga

    2010-07-01

    Full Text Available The paper proposes novel molecular designs for rare-earth complexes involving the introduction of two different phosphine oxide structures into one rare-earth ion. These designs are effective for improving solubility and emission intensity. Additionally, the complexes are indispensable for realizing high performances in LEDs and security media. The thermodynamic properties of Eu(III complexes are correlated with the solubility. Correlations between coordination structures and emission intensity were explained by NMR analysis. The luminous flux of red LED devices with Eu(III complexes is very high (20 mA, 870 m lumen. A new white LED has its largest spectra intensity in the red region and a human look much more vividly under this light.

  14. Conformational analysis, UV-VIS, MESP, NLO and NMR studies of 6-methoxy-1,2,3,4-tetrahydronaphthalene.

    Science.gov (United States)

    Arivazhagan, M; Kavitha, R; Subhasini, V P

    2014-07-15

    The detailed HF and B3LYP/6-311++G(d,p) comparative studies on the complete FT-IR and FT-Raman spectra of 6-methoxy-1,2,3,4-tetrahydronaphthalene [MTHN] have been studied. In view of the special properties and uses, the present investigation has been undertaken to provide a satisfactorily vibrational analysis of 6-methoxy-1,2,3,4-tetrahydronaphthalene. Therefore, a thorough Raman, IR, molecular electrostatic potential (MESP), non-linear optical (NLO) properties, UV-VIS, HOMO-LUMO and NMR spectroscopic investigation are reported complemented by B3LYP theoretical predictions with basis set 6-311++G(d,p) to provide novel insight on vibrational assignments and conformational stability of MTHN. Potential energy surface scans (PES) of the CH3 group are undertaken to shed light on the rather complicated conformational interchanges in the compound under investigation. Copyright © 2014 Elsevier B.V. All rights reserved.

  15. High-resolution magic angle spinning proton NMR analysis of human prostate tissue with slow spinning rates.

    Science.gov (United States)

    Taylor, Jennifer L; Wu, Chin-Lee; Cory, David; Gonzalez, R Gilberto; Bielecki, Anthony; Cheng, Leo L

    2003-09-01

    The development of high-resolution magic angle spinning (HR-MAS) NMR spectroscopy for intact tissue analysis and the correlations between the measured tissue metabolites and disease pathologies have inspired investigations of slow-spinning methodologies to maximize the protection of tissue pathology structures from HR-MAS centrifuging damage. Spinning sidebands produced by slow-rate spinning must be suppressed to prevent their complicating the spectral region of metabolites. Twenty-two human prostatectomy samples were analyzed on a 14.1T spectrometer, with HR-MAS spinning rates of 600 Hz, 700 Hz, and 3.0 kHz, a repetition time of 5 sec, and employing various rotor-synchronized suppression methods, including DANTE, WATERGATE, TOSS, and PASS pulse sequences. Among them, DANTE, as the simplest scheme, has shown the most potential in suppression of tissue water signals and spinning sidebands, as well as in quantifying metabolic concentrations. Copyright 2003 Wiley-Liss, Inc.

  16. Autonomous driving in NMR.

    Science.gov (United States)

    Perez, Manuel

    2017-01-01

    The automatic analysis of NMR data has been a much-desired endeavour for the last six decades, as it is the case with any other analytical technique. This need for automation has only grown as advances in hardware; pulse sequences and automation have opened new research areas to NMR and increased the throughput of data. Full automatic analysis is a worthy, albeit hard, challenge, but in a world of artificial intelligence, instant communication and big data, it seems that this particular fight is happening with only one technique at a time (let this be NMR, MS, IR, UV or any other), when the reality of most laboratories is that there are several types of analytical instrumentation present. Data aggregation, verification and elucidation by using complementary techniques (e.g. MS and NMR) is a desirable outcome to pursue, although a time-consuming one if performed manually; hence, the use of automation to perform the heavy lifting for users is required to make the approach attractive for scientists. Many of the decisions and workflows that could be implemented under automation will depend on the two-way communication with databases that understand analytical data, because it is desirable not only to query these databases but also to grow them in as much of an automatic manner as possible. How these databases are designed, set up and the data inside classified will determine what workflows can be implemented. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

  17. Analysis of RF heating and sample stability in aligned static solid-state NMR spectroscopy

    Science.gov (United States)

    Li, Conggang; Mo, Yiming; Hu, Jun; Chekmenev, Eduard; Tian, Changlin; Gao, Fei Philip; Fu, Riqiang; Gor'kov, Peter; Brey, William; Cross, Timothy A.

    2006-05-01

    Sample instability during solid-state NMR experiments frequently arises due to RF heating in aligned samples of hydrated lipid bilayers. A new, simple approach for estimating sample temperature is used to show that, at 9.4 T, sample heating depends mostly on 1H decoupling power rather than on 15N irradiation in PISEMA experiments. Such heating for different sample preparations, including lipid composition, salt concentration and hydration level was assessed and the hydration level was found to be the primary parameter correlated with sample heating. The contribution to RF heating from the dielectric loss appears to be dominant under our experimental conditions. The heat generated by a single scan was approximately calculated from the Q values of the probe, to be a 1.7 °C elevation per single pulse sequence iteration under typical sample conditions. The steady-state sample temperature during PISEMA experiments can be estimated based on the method presented here, which correlates the loss factor with the temperature rise induced by the RF heating of the sample.

  18. Analysis of the hydrolysis of inulin using real time 1H NMR spectroscopy

    Science.gov (United States)

    Barclay, Thomas; Ginic-Markovic, Milena; Johnston, Martin R.; Cooper, Peter D.; Petrovsky, Nikolai

    2012-01-01

    The hydrolysis of various carbohydrates was investigated under acidic conditions in real time by 1H NMR spectroscopy, with a focus on the polysaccharide inulin. Sucrose was used as a model compound to illustrate the applicability of this technique. The hydrolysis of sucrose was shown to follow pseudo first order kinetics and have an activation energy of 107.0 kJ.mol−1 (s.d. 1.7 kJ.mol−1). Inulin, pullulan and glycogen also all followed pseudo first order kinetics, but had an initiation phase at least partially generated by the protonation of the glycosidic bonds. It was also demonstrated that polysaccharide chain length has an effect on the hydrolysis of inulin. For short chain inulin (DPn 18, s.d. 0.70) the activation energy calculated for the hydrolytic cleavage of glucose was similar to sucrose at 108.5 kJ.mol−1 (std. dev. 0.60). For long chain inulin (DPn 30, s.d. 1.3) the activation energy for the hydrolytic cleavage of glucose was reduced to 80.5 kJ.mol−1 (s.d. 2.3 kJ.mol−1). This anomaly has been attributed to varied conformations for the two different lengths of inulin chain in solution. PMID:22464225

  19. On low-dimensional models at NMR line shape analysis in nanomaterial systems

    Science.gov (United States)

    Kucherov, M. M.; Falaleev, O. V.

    2018-03-01

    We present a model of localized spin dynamics at room temperature for the low-dimensional solid-state spin system, which contains small ensembles of magnetic nuclei (N ~ 40). The standard spin Hamiltonian (XXZ model) is the sum of the Zeeman term in a strong external magnetic field and the magnetic dipole interaction secular term. The 19F spins in a single crystal of fluorapatite [Ca5(PO4)3F] have often been used to approximate a one-dimensional spin system. If the constant external field is parallel to the c axis, the 3D 19F system may be treated as a collection of many identical spin chains. When considering the longitudinal part of the secular term, we suggest that transverse component of a spin in a certain site rotates in a constant local magnetic field. This field changes if the spin jumps to another site. On return, this spin continues to rotate in the former field. Then we expand the density matrix in a set of eigenoperators of the Zeeman Hamiltonian. A system of coupled differential equations for the expansion coefficients then solved by straightforward numerical methods, and the fluorine NMR line shapes of fluorapatite for different chain lengths are calculated.

  20. Prediction of peak overlap in NMR spectra

    International Nuclear Information System (INIS)

    Hefke, Frederik; Schmucki, Roland; Güntert, Peter

    2013-01-01

    Peak overlap is one of the major factors complicating the analysis of biomolecular NMR spectra. We present a general method for predicting the extent of peak overlap in multidimensional NMR spectra and its validation using both, experimental data sets and Monte Carlo simulation. The method is based on knowledge of the magnetization transfer pathways of the NMR experiments and chemical shift statistics from the Biological Magnetic Resonance Data Bank. Assuming a normal distribution with characteristic mean value and standard deviation for the chemical shift of each observable atom, an analytic expression was derived for the expected overlap probability of the cross peaks. The analytical approach was verified to agree with the average peak overlap in a large number of individual peak lists simulated using the same chemical shift statistics. The method was applied to eight proteins, including an intrinsically disordered one, for which the prediction results could be compared with the actual overlap based on the experimentally measured chemical shifts. The extent of overlap predicted using only statistical chemical shift information was in good agreement with the overlap that was observed when the measured shifts were used in the virtual spectrum, except for the intrinsically disordered protein. Since the spectral complexity of a protein NMR spectrum is a crucial factor for protein structure determination, analytical overlap prediction can be used to identify potentially difficult proteins before conducting NMR experiments. Overlap predictions can be tailored to particular classes of proteins by preparing statistics from corresponding protein databases. The method is also suitable for optimizing recording parameters and labeling schemes for NMR experiments and improving the reliability of automated spectra analysis and protein structure determination.

  1. NMR, water and plants

    NARCIS (Netherlands)

    As, van H.

    1982-01-01

    This Thesis describes the application of a non-destructive pulsed proton NMR method mainly to measure water transport in the xylem vessels of plant stems and in some model systems. The results are equally well applicable to liquid flow in other biological objects than plants, e.g. flow of blood and

  2. Application of Spectroscopic Techniques (FT-IR, 13C NMR) to the analysis of humic substances in volcanic soils along an environmental gradient (Tenerife, Canary Islands, Spain)

    Science.gov (United States)

    Rodriguez Rodriguez, Antonio; María Armas Herrera, Cecilia; González Pérez, José Antonio; González-Vila, Francisco Javier; Arbelo Rodríguez, Carmen Dolores; Mora Hernández, Juan Luis; Polvillo Polo, Oliva

    2010-05-01

    Andosols and andic soils are considered as efficient C-sinks in terms of C sequestration. These soils are usually developed from volcanic materials, and are characterized by a predominance of short-range ordered minerals like allophanes, imogolite and other Fe and Al oxyhydroxides. Such materials occur commonly associated with organic compounds, thus generating highly stable organo-mineral complexes and leading to the accumulation of a high amount of organic carbon. Spectroscopic methods like FT-IR and 13C NMR are suitable for the analysis of the chemical structure of soil humic substances, and allow identifying distinct functional groups and protein, lipids, lignin, carbohydrate-derived fragments. In this work we study the structural features of four soils developed on Pleistocene basaltic lavae in Tenerife (Canary Island, Spain), distributed along an altitudinal climatic gradient. The soil sequence comprises soils with different degree of geochemical evolution and andic character, including a mineral ‘Hypersalic Solonchak' (Tabaibal de Rasca), a slightly vitric ‘Luvic Phaeozem' (Los Frailes), a degraded and shallow ‘Endoleptic, fulvic, silandic Andosol' (Siete Lomas), and a well-developed and deep ‘Fulvic, silandic, Andosol' (Ravelo). Samples of the raw soil and humic and fulvic acids isolated from the surface horizons were analyzed. The results show a low content of organic carbon in the mineral soil, the inherited humin predominating, and a very high content of humic and fulvic acids in Andosols. The FT-IR and 13C NMR spectra of the raw soil samples show a low resolution, related to interferences from mineral complexes signals, particularly in soils with lower organic carbon content. 13C NMR shows a predominance of O-alkyl carbon (derived of carbohydrates) in andic soils, whereas O-alkyl and aromatic fractions are most evident in the mineral soil. The humic acids spectra are characterized by a dominance of alkyl and aromatic fractions with a high degree

  3. Using Empirical Rules from 13C NMR Analysis to Determine the Stereochemistry of the Epoxide Located at the 5,6-position of Decalinic Systems

    Directory of Open Access Journals (Sweden)

    Raquel M. Cravero

    2000-03-01

    Full Text Available An empiric rule derived from the analysis of the 13C NMR spectral data, allowed us to determine 5,6-epoxide stereochemistry on decalinic systems and a discussion of the scope and limitations of this rule and its extension to other carbon squeletons, is presented.

  4. 1H NMR-Based Metabolomic Analysis of Sub-Lethal Perfluorooctane Sulfonate Exposure to the Earthworm, Eisenia fetida, in Soil

    Directory of Open Access Journals (Sweden)

    Myrna J. Simpson

    2013-08-01

    Full Text Available 1H NMR-based metabolomics was used to measure the response of Eisenia fetida earthworms after exposure to sub-lethal concentrations of perfluorooctane sulfonate (PFOS in soil. Earthworms were exposed to a range of PFOS concentrations (five, 10, 25, 50, 100 or 150 mg/kg for two, seven and fourteen days. Earthworm tissues were extracted and analyzed by 1H NMR. Multivariate statistical analysis of the metabolic response of E. fetida to PFOS exposure identified time-dependent responses that were comprised of two separate modes of action: a non-polar narcosis type mechanism after two days of exposure and increased fatty acid oxidation after seven and fourteen days of exposure. Univariate statistical analysis revealed that 2-hexyl-5-ethyl-3-furansulfonate (HEFS, betaine, leucine, arginine, glutamate, maltose and ATP are potential indicators of PFOS exposure, as the concentrations of these metabolites fluctuated significantly. Overall, NMR-based metabolomic analysis suggests elevated fatty acid oxidation, disruption in energy metabolism and biological membrane structure and a possible interruption of ATP synthesis. These conclusions obtained from analysis of the metabolic profile in response to sub-lethal PFOS exposure indicates that NMR-based metabolomics is an excellent discovery tool when the mode of action (MOA of contaminants is not clearly defined.

  5. 31P NMR analysis of intracellular pH of Swiss Mouse 3T3 cells: effects of extracellular Na+ and K+ and mitogenic stimulation.

    Science.gov (United States)

    Civan, M M; Williams, S R; Gadian, D G; Rozengurt, E

    1986-01-01

    Swiss mouse 3T3 cells grown on microcarrier beads were superfused with electrolyte solution during continuous NMR analysis. Conventional 31P and 19F probes of intracellular pH (pHc) were found to be impracticable. Cells were therefore superfused with 1 to 4 mM 2-deoxyglucose, producing a large intracellular, pH-sensitive signal of 2-deoxyglucose phosphate (2DGP). The intracellular incorporation of 2DGP inhibited the Embden-Meyerhof pathway. However, intracellular ATP was at least in part retained and the cellular responsivity to changes in extracellular ionic composition and to the application of growth factors proved intact. Transient replacement of external Na+ with choline or K+ reversibly acidified the intracellular fluids. Quiescent cells and mitogenically stimulated cells displayed the same dependence of shifts in pHc on external Na+ concentration (CoNa). PHc also depended on intracellular Na+ concentration (CcNa). Increasing ccNa by withdrawing external K+ (thereby inhibiting the Na,K-pump) caused reversible intracellular acidification; subsequently reducing CoNa produced a larger acid shift in pHc than with external K+ present. Comparison of separate preparations indicated that pHc was higher in stimulated than in quiescent cells. Transient administration of mitogens also reversibly alkalinized quiescent cells studied continuously. This study documents the feasibility of monitoring pHc of Swiss mouse 3T3 cells using 31P NMR analysis of 2DGP. The results support the concept of a Na/H antiport operative in these cells, both in quiescence and after mitogenic stimulation. The data document by an independent technique that cytoplasmic alkalinization is an early event in mitogenesis, and that full activity of the Embden-Meyerhof pathway is not required for the expression of this event.

  6. Secondary Analysis for Results Tracking Database

    Data.gov (United States)

    US Agency for International Development — The Secondary Analysis and Results Tracking (SART) activity provides support for the development of two databases to manage secondary and third-party data, data...

  7. Protein samples for NMR: expression and analysis without purification, and stabilization by covalent cyclization

    International Nuclear Information System (INIS)

    Otting, G.; Ozawa, K.; Prosselkov, P.; Williams, N.K.; Dixon, N.E.; Liepinsh, E.

    2002-01-01

    Full text: A modified cell-free in vitro expression system was established for the expression of milligram quantities of protein per mL reaction medium. Expression levels of the E coli cytoplasmic peptidyl-prolyl cis-trans isomerase, PpiB, in 0 6 mL reaction medium were sufficient for the direct recording of clean 15N-HSQC spectra without chromatographic purification or sample concentration steps, using a 600 MHz NMR spectrometer with cryoprobe. Besides providing a route to high-throughput sample preparation, in vitro expression systems are known to be highly economic in their utilization of selectively labelled ammo acids. Using dual-selective labelling with 15N- and 13C-labelled amino acids, the 15N-HSQC cross peaks of strategically selected ammo acids can readily be identified and monitored for their response to the presence of ligand molecules, again without sample purification. 2) The N-terminal domain of E coli DnaB is a protein of ca 110 residues with a structured core composed of 6 helices. Additional segments of 10 residues each at the N- and C-termini are highly mobile. Both ends are close in space and can be linked together in a covalent peptide bond using intern technology. The core structures of linear (lin-DnaB-N) and cyclized (cz-DnaB-N) protein are conserved, as evidenced by superimposable NOESY spectra and chemical shifts. The linker segment in cz-DnaB-N is mobile as shown by 1H-15N NOEs. Yet, the cyclic protein melts about 10 degrees higher than the linear version. A stabilization free energy of ca 2 kcal/mol is in agreement with predictions based on the reduced entropy in the unfolded state. Amide proton exchange rates are much slower in the cyclic protein and reveal cooperative exchange through total, global unfolding at a rate of once every 100 minutes in the linear protein

  8. The quantitative in vivo analysis of the muscle degeneration in Duchenne type muscular dystrophy using NMR-CT

    International Nuclear Information System (INIS)

    Ikehira, Hiroo; Aoki, Yoshio; Matsumura, Kiichiro

    1986-01-01

    In order to develop a simple noninvasive method to determine progressive stages of Duchenne type muscular dystrophy (DMD), we proposed two muscular degeneration parameters calculated from NMR-CT data. The parameters are W.C.P. (water concentration parameter) and F.C.P. (fat concentration parameter). We examined 15 normal male and 10 normal female volunteers, 19 carrier females and 21 DMD patients. The normal value indicated 0 to 30 % F.C.P., while the results of DMD patients showed abnormally high W.C.P. at the early stage and increased F.C.P. corresponding to the clinical stages (Ueda's disability stages). But there was not any difference between the DMD carrier's data and the control data. The present study suggested the possibilities of clinical stagings and early detection of DMD with the parameters. (author)

  9. Analysis of the PISC II trials results

    International Nuclear Information System (INIS)

    Haines, N.

    1988-01-01

    The paper presents the analysis scheme of the Programme for the Inspection of Steel Components PISC II trial results. The objective of the PISC II exercise is to evaluate the effectiveness of current and advanced NDT techniques for inspection of reactor pressure vessel components. The analysis scheme takes data from the Round Robin Trial (RRT) and Destructive Examination, then reduces it to a manageable form in order to present useful conclusions on the effectiveness of NDT. A description is given of the data provided by RRT, the data analysis scheme, the definition of analysis parameters, and the main methods of data presentation. (U.K.)

  10. Vibrational spectra, molecular structure, NBO, UV, NMR, first order hyperpolarizability, analysis of 4-Methoxy-4'-Nitrobiphenyl by density functional theory.

    Science.gov (United States)

    Govindarasu, K; Kavitha, E

    2014-03-25

    In this study, geometrical optimization, spectroscopic analysis, electronic structure and nuclear magnetic resonance studies of 4-Methoxy-4'-Nitrobiphenyl (abbreviated as 4M4'NBPL) were investigated by utilizing HF and DFT/B3LYP with 6-31G(d,p) as basis set. The equilibrium geometry, vibrational wavenumbers and the first order hyperpolarizability of the 4M4'NBPL have been calculated with the help of density functional theory computations. The FT-IR and FT-Raman spectra were recorded in the region 4000-400 cm(-1) and 3500-50 cm(-1) respectively. Natural Bond Orbital (NBO) analysis is also used to explain the molecular stability. The UV-Vis absorption spectra of the title compound dissolved in chloroform were recorded in the range of 200-800 cm(-1). The HOMO-LUMO energy gap explains the charge interaction taking place within the molecule. Good correlation between the experimental (1)H and (13)C NMR chemical shifts in chloroform solution and calculated GIAO shielding tensors were found. The dipole moment, linear polarizability and first order hyperpolarizability values were also computed. The linear polarizability and first order hyperpolarizability of the studied molecule indicate that the compound is a good candidate of nonlinear optical materials. The chemical reactivity and thermodynamic properties of 4M4'NBPL at different temperature are calculated. In addition, molecular electrostatic potential (MEP), frontier molecular orbitals (FMO) analysis were investigated using theoretical calculations. Published by Elsevier B.V.

  11. Structure and dynamics of a [1:1] drug-DNA complex: Analysis of 2D NMR data using molecular mechanics and molecular dynamics calculations

    International Nuclear Information System (INIS)

    Sarma, R.H.; Sarma, M.H.; Umemoto, K.

    1990-01-01

    1D/2D NMR studies are reported for a [1:1] complex of d(GA 4 T 4 C) 2 and Dst2 (an analogue of distamycin A). Full- Matrix NOESY Simulations, Molecular Mechanics and Molecular Dynamics Calculations are performed to analyze the NMR data. Results show that drug-DNA complex formation is driven by static features like H-bonding and steric interactions in the minor-groove of DNA. As a consequence of drug binding, a non-linear oscillatory mode is activated. In this mode the molecule samples equilibrium structural states of difference degrees of bending. It is noted that these structures belong to three distinctly different energy wells that satisfy the same NMR data. 14 refs., 4 figs., 2 tabs

  12. Tracking Sodium-Antimonide Phase Transformations in Sodium-Ion Anodes: Insights from Operando Pair Distribution Function Analysis and Solid-State NMR Spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Allan, Phoebe K. [University of Cambridge, University Chemical Laboratory, Lensfield Road, Cambridge, CB2 1EW, U.K.; Gonville and Caius College, Trinity; Griffin, John M. [University of Cambridge, University Chemical Laboratory, Lensfield Road, Cambridge, CB2 1EW, U.K.; Darwiche, Ali [Institut; Réseau sur le Stockage Electrochimique de l’Energie (RS2E), FR CNRS 3459, 80039 Amiens Cedex, France; Borkiewicz, Olaf J. [X-ray; Wiaderek, Kamila M. [X-ray; Chapman, Karena W. [X-ray; Morris, Andrew J. [Theory of; Chupas, Peter J. [X-ray; Monconduit, Laure [Institut; Réseau sur le Stockage Electrochimique de l’Energie (RS2E), FR CNRS 3459, 80039 Amiens Cedex, France; Grey, Clare P. [University of Cambridge, University Chemical Laboratory, Lensfield Road, Cambridge, CB2 1EW, U.K.

    2016-02-15

    Operando pair distribution function (PDF) analysis and ex situ Na-23 magic-angle spinning solid-state nuclear magnetic resonance (MAS ssNMR) spectroscopy are used to gain insight into the alloying mechanism of high-capacity antimony anodes for sodium-ion batteries. Subtraction of the PDF of crystalline NaxSb phases from the total PDF, an approach constrained by chemical phase information gained from Na-23 ssNMR in reference to relevant model compounds, identifies two previously uncharacterized intermediate species formed electro-chemically; a-Na3-xSb (x approximate to 0.4-0.5), a structure locally similar to crystalline Na3Sb (c-Na3Sb) but with significant numbers of sodium vacancies and a limited correlation length, and a-Na1.7Sb, a highly amorphous structure featuring some Sb-Sb bonding. The first sodiation breaks down the crystalline antimony to form first a-Na3-xSb and, finally, crystalline Na3Sb. Desodiation results in the formation of an electrode formed of a composite of crystalline and amorphous antimony networks. We link the different reactivity of these networks to a series of sequential sodiation reactions manifesting as a cascade of processes observed in the electrochemical profile of subsequent cycles. The amorphofis network reacts at higher voltages reforming a-Na1.7Sb, then a-Na3-xSb, whereas lower potentials are required for the sodiation of crystalline antimony, which reacts to form a-Na3-xSb without the formation of a-Na3-xSb. a-Na3-xSb is converted to crystalline Na3Sb at the end of the second discharge. We find no evidence of formation of NaSb. Variable temperature Na-23 NMR experiments reveal significant sodium mobility within c-Na3Sb; this is a possible contributing factor to the excellent rate performance of Sb anodes.

  13. Detecting plant-climate interactions over decades-millennia using NMR isotopomer analysis

    Science.gov (United States)

    Ehlers, Ina; Augusti, Angela; Köhler, Iris; Wieloch, Thomas; Zuidema, Pieter; Robertson, Iain; Nilsson, Mats; Marshall, John; Schleucher, Jürgen

    2016-04-01

    Increasing CO2 and climate change affect photosynthesis, which creates a critical influence on the global C cycle and on the future productivity of crops and forests. Manipulative experiments (e.g. FACE) impose step increases in [CO2], and are limited to few locations and to time spans of years, while responses over decades and centuries are critical for Earth system models. To overcome these limitations, we have developed a new method - isotopomer analysis - that allows deducing plant C metabolism by analysis of primary plant photosynthates (Ehlers et al., PNAS 2015, 15585) or tree rings. We apply the method to material from manipulation (CO2, T) experiments, and to remnant - including subfossil - plant material. Thus, metabolic responses can be identified in FACE experiments, and it can be tested to what degree these responses are maintained during gradual environmental changes over decades-millennia. Isotopomer proxies developed using FACE experiments can then be used to reconstruct physiological and climatic changes by retrospective analysis, thus bridging a gap between experimental plant sciences and paleo research. In experiments on annual plants, we have found that specific deuterium isotopomers in photosynthetic glucose reflect the ratio of oxygenation to carboxylation at Rubisco, a central metabolic branching that is the origin of the photorespiration flux in all C3 plants. We found that increasing atmospheric [CO2] over the 20th century has reduced the photorespiration / photosynthesis ratio in all investigated C3 species, with no evidence for acclimatory reactions by the plants. Results on the peat moss Spagnum fuscum suggest a mechanism for increasing peat accumulation rates, a major global C sink. For 12 tree species from five continents, we observe that the CO2 increase since industrialization has reduced the photorespiration / photosynthesis ratio. However, the observed reduction is ca. 50 % smaller than expected from CO2 manipulation experiments

  14. NMR Studies of Polymer Nanocomposites

    National Research Council Canada - National Science Library

    Greenbaum, Steve

    2001-01-01

    .... The primary tool is pulsed field gradient NMR. A static field gradient method was developed which makes possible variable pressure diffusion measurement, and the application to the important fuel cell membrane NAFION constitute the first results...

  15. Relativity Concept Inventory: Development, Analysis, and Results

    Science.gov (United States)

    Aslanides, J. S.; Savage, C. M.

    2013-01-01

    We report on a concept inventory for special relativity: the development process, data analysis methods, and results from an introductory relativity class. The Relativity Concept Inventory tests understanding of relativistic concepts. An unusual feature is confidence testing for each question. This can provide additional information; for example,…

  16. Multivariate Analysis of Two-Dimensional 1H, 13C Methyl NMR Spectra of Monoclonal Antibody Therapeutics To Facilitate Assessment of Higher Order Structure.

    Science.gov (United States)

    Arbogast, Luke W; Delaglio, Frank; Schiel, John E; Marino, John P

    2017-11-07

    Two-dimensional (2D) 1 H- 13 C methyl NMR provides a powerful tool to probe the higher order structure (HOS) of monoclonal antibodies (mAbs), since spectra can readily be acquired on intact mAbs at natural isotopic abundance, and small changes in chemical environment and structure give rise to observable changes in corresponding spectra, which can be interpreted at atomic resolution. This makes it possible to apply 2D NMR spectral fingerprinting approaches directly to drug products in order to systematically characterize structure and excipient effects. Systematic collections of NMR spectra are often analyzed in terms of the changes in specifically identified peak positions, as well as changes in peak height and line widths. A complementary approach is to apply principal component analysis (PCA) directly to the matrix of spectral data, correlating spectra according to similarities and differences in their overall shapes, rather than according to parameters of individually identified peaks. This is particularly well-suited for spectra of mAbs, where some of the individual peaks might not be well resolved. Here we demonstrate the performance of the PCA method for discriminating structural variation among systematic sets of 2D NMR fingerprint spectra using the NISTmAb and illustrate how spectral variability identified by PCA may be correlated to structure.

  17. Basics of spectroscopic instruments. Hardware of NMR spectrometer

    International Nuclear Information System (INIS)

    Sato, Hajime

    2009-01-01

    NMR is a powerful tool for structure analysis of small molecules, natural products, biological macromolecules, synthesized polymers, samples from material science and so on. Magnetic Resonance Imaging (MRI) is applicable to plants and animals Because most of NMR experiments can be done by an automation mode, one can forget hardware of NMR spectrometers. It would be good to understand features and performance of NMR spectrometers. Here I present hardware of a modern NMR spectrometer which is fully equipped with digital technology. (author)

  18. GC-MS and NMR analysis of the bioactive compounds from the crude extracts of Waltheria indica and the histopathological changes induced in albino rats challenged with Naja nigricollis venom

    Directory of Open Access Journals (Sweden)

    Philip Ilani

    2016-05-01

    Full Text Available Objective: To develop a characteristic fingerprint of the different chemical compounds of plant by gas chromatography-mass spectrometer (GC-MS and nuclear magnetic resonance (NMR analysis and assess the effect of the crude extract on histological changes induced in Naja nigricollis (N. nigricollis envenomed albino rats. Methods: The coarsely powdered Waltheria indica (W. indica whole plant material was extracted using 70% methanol. GC-MS analysis was carried out using a Shimadzu GC-MS QP 2010 plus system of gas chromatography interfaced to a mass spectrometer. The identification of components was based on National Institute of Standard and Technology-08 and Willey-8 libraries. Hydrogen-NMR spectra of the extracts was performed using Bruker Biospin Avance 400-MHz NMR spectrophotometer with a 5 mm broad inverse probe head, equipped with shielded z-gradient accessories and C-13 NMR hetero-nuclear single quantum correction was carried out using the Brucker’s standard pulse library. The efficacy of the crude extract of W. indica whole plant was tested and the lesions induced in the liver, brain and kidney of albino rats challenged with N. nigricollis were analyzed by light microscopy. Results: The identification of the bioactive compounds from W. indica by GC-MS analysis revealed 41 peaks. A total of 38 compounds were identified with majority having important pharmacological activities that included anti-microbial, anti-cancer, anti-oxidant antiinflammatory, anti-allergenic, anti-ageing, anti-arthritic, larvicidal, anti-convulsant and herbicidal activities. C-13 and hydrogen-NMR analysis of W. indica elucidated key bioactive compounds in the whole plant that were consistent with the classes of bioactive compounds detected by GC-MS analysis. The efficacy of the crude extract of W. indica whole plant in ameliorating histopathological lesions induced in the liver, brain and kidney of albino rats challenged with N. nigricollis venom revealed the

  19. NMR for direct determination of K(m) and V(max) of enzyme reactions based on the Lambert W function-analysis of progress curves.

    Science.gov (United States)

    Exnowitz, Franziska; Meyer, Bernd; Hackl, Thomas

    2012-03-01

    (1)H NMR spectroscopy was used to follow the cleavage of sucrose by invertase. The parameters of the enzyme's kinetics, K(m) and V(max), were directly determined from progress curves at only one concentration of the substrate. For comparison with the classical Michaelis-Menten analysis, the reaction progress was also monitored at various initial concentrations of 3.5 to 41.8mM. Using the Lambert W function the parameters K(m) and V(max) were fitted to obtain the experimental progress curve and resulted in K(m)=28mM and V(max)=13μM/s. The result is almost identical to an initial rate analysis that, however, costs much more time and experimental effort. The effect of product inhibition was also investigated. Furthermore, we analyzed a much more complex reaction, the conversion of farnesyl diphosphate into (+)-germacrene D by the enzyme germacrene D synthase, yielding K(m)=379μM and k(cat)=0.04s(-1). The reaction involves an amphiphilic substrate forming micelles and a water insoluble product; using proper controls, the conversion can well be analyzed by the progress curve approach using the Lambert W function. Copyright © 2011. Published by Elsevier B.V.

  20. Measurement of -OH groups in coals of different rank using microwave methodology, and the development of quantitative solid state n.m.r. methods for in situ analysis

    Energy Technology Data Exchange (ETDEWEB)

    Monsef-Mirzai, P.; McWhinnie, W.R.; Perry, M.C.; Burchill, P. [Aston University, Birmingham (United Kingdom). Dept. of Chemical Engineering and Applied Chemistry

    1995-05-01

    Experiments with both model compounds (substituted phenols) and with 11 coals (nine British and two American) have established that microwave heating will greatly accelerate silylation reactions of the phenolic -OH groups, e.g. for Creswell coal complete silylation of -OH groups occurs in 35 min in the microwave oven, whereas 24 h is required using a bench reflux technique. Microwave reaction times for coals vary from 35 min to 3 h for more dense coals such as Cortonwood. The above observations have allowed the development of a `one pot` silylation of coal, followed by an in situ analysis of the added Me{sub 3}Si- groups by quantitative {sup 29}Si magic angle spinning nuclear magnetic resonance (MAS n.m.r.) spectroscopy. The development of a quantitative n.m.r. method required the determination of {sup 29}Si spin lattice relaxation times, T{sub 1}, e.g. for silylated coals T{sub 1} {approximately} 8s; for silylated phenols, T{sub 1} {approximately} 25s; for the synthetic smectite clay laponite, T{sub 1} {approximately} 25 s; and for Ph{sub 3}SiH, T{sub 1} {approximately} 64 s. Inert laponite was selected as the standard. The requirement to wait for five T{sub 1 max} between pulses, together with the relatively low natural abundance of {sup 29}Si (4.71%), results in rather long accumulation times to obtain spectra of analytical quality (8-48 h). However, in comparison with other methods, even in the most unfavourable case, the total time from commencement of analysis to result may be described as `rapid`. The results for O{sub OH}/O{sub total} obtained are compared with other literature data. Comparison with ketene data, for example, shows agreement to vary from excellent (Creswell) through satisfactory (Cortonwood) to poor (Pittsburgh). Even in cases where agreement with ketene data is less good, the silylation results may be close to estimates made via other acetylation methods. Possible reasons for the variations observed are discussed. 18 refs., 2 figs., 7 tabs.

  1. Molecular characterization of dissolved organic matter from subtropical wetlands: a comparative study through the analysis of optical properties, NMR and FTICR/MS

    Science.gov (United States)

    Hertkorn, Norbert; Harir, Mourad; Cawley, Kaelin M.; Schmitt-Kopplin, Philippe; Jaffé, Rudolf

    2016-04-01

    Wetlands provide quintessential ecosystem services such as maintenance of water quality, water supply and biodiversity, among others; however, wetlands are also among the most threatened ecosystems worldwide. Natural dissolved organic matter (DOM) is an abundant and critical component in wetland biogeochemistry. This study describes the first detailed, comparative, molecular characterization of DOM in subtropical, pulsed, wetlands, namely the Everglades (USA), the Pantanal (Brazil) and the Okavango Delta (Botswana), using optical properties, high-field nuclear magnetic resonance (NMR) and ultrahigh-resolution mass spectrometry (FT-ICRMS), and compares compositional features to variations in organic matter sources and flooding characteristics (i.e., differences in hydroperiod). While optical properties showed a high degree of variability within and between the three wetlands, analogies in DOM fluorescence properties were such that an established excitation emission matrix fluorescence parallel factor analysis (EEM-PARAFAC) model for the Everglades was perfectly applicable to the other two wetlands. Area-normalized 1H NMR spectra of selected samples revealed clear distinctions of samples while a pronounced congruence within the three pairs of wetland DOM readily suggested the presence of an individual wetland-specific molecular signature. Within sample pairs (long- vs. short-hydroperiod sites), internal differences mainly referred to intensity variations (denoting variable abundance) rather than to alterations of NMR resonances positioning (denoting diversity of molecules). The relative disparity was largest between the Everglades long- and short-hydroperiod samples, whereas Pantanal and Okavango samples were more alike among themselves. Otherwise, molecular divergence was most obvious in the case of unsaturated protons (δH > 5 ppm). 2-D NMR spectroscopy for a particular sample revealed a large richness of aliphatic and unsaturated substructures, likely derived from

  2. Detection of Butter Adulteration with Lard by Employing (1)H-NMR Spectroscopy and Multivariate Data Analysis.

    Science.gov (United States)

    Fadzillah, Nurrulhidayah Ahmad; Man, Yaakob bin Che; Rohman, Abdul; Rosman, Arieff Salleh; Ismail, Amin; Mustafa, Shuhaimi; Khatib, Alfi

    2015-01-01

    The authentication of food products from the presence of non-allowed components for certain religion like lard is very important. In this study, we used proton Nuclear Magnetic Resonance ((1)H-NMR) spectroscopy for the analysis of butter adulterated with lard by simultaneously quantification of all proton bearing compounds, and consequently all relevant sample classes. Since the spectra obtained were too complex to be analyzed visually by the naked eyes, the classification of spectra was carried out.The multivariate calibration of partial least square (PLS) regression was used for modelling the relationship between actual value of lard and predicted value. The model yielded a highest regression coefficient (R(2)) of 0.998 and the lowest root mean square error calibration (RMSEC) of 0.0091% and root mean square error prediction (RMSEP) of 0.0090, respectively. Cross validation testing evaluates the predictive power of the model. PLS model was shown as good models as the intercept of R(2)Y and Q(2)Y were 0.0853 and -0.309, respectively.

  3. SYNTHESIS, IR AND NMR SPECTRAL CORRELATIONS IN SOME ...

    African Journals Online (AJOL)

    Preferred Customer

    correlated with Hammett substituent constants, F and R parameters using single and multi-linear regression analysis. From the results of statistical analysis, the effect of substituents on the above spectral data has been studied. KEY WORDS: Diimines, IR and NMR spectra, Spectral correlation, Hammett sigma constants.

  4. Relativity concept inventory: Development, analysis, and results

    Directory of Open Access Journals (Sweden)

    J. S. Aslanides

    2013-05-01

    Full Text Available We report on a concept inventory for special relativity: the development process, data analysis methods, and results from an introductory relativity class. The Relativity Concept Inventory tests understanding of relativistic concepts. An unusual feature is confidence testing for each question. This can provide additional information; for example, high confidence correlated with incorrect answers suggests a misconception. A novel aspect of our data analysis is the use of Monte Carlo simulations to determine the significance of correlations. This approach is particularly useful for small sample sizes, such as ours. Our results show a gender bias that was not present in course assessment, similar to that reported for the Force Concept Inventory.

  5. Introducing Undergraduate Students to Metabolomics Using a NMR-Based Analysis of Coffee Beans

    Science.gov (United States)

    Sandusky, Peter Olaf

    2017-01-01

    Metabolomics applies multivariate statistical analysis to sets of high-resolution spectra taken over a population of biologically derived samples. The objective is to distinguish subpopulations within the overall sample population, and possibly also to identify biomarkers. While metabolomics has become part of the standard analytical toolbox in…

  6. Comparison of the 1H NMR analysis of solids by the CRAMPS and MAS-only techniques

    Science.gov (United States)

    Dec, Steven F.; Bronnimann, Charles E.; Wind, Robert A.; Maciel, Gary E.

    1H NMR spectra are reported on eight representative solid samples, including pure powdered crystalline samples, synthetic organic polymers, a silica gel, HY zeolite, and a lignite. Spectra were obtained by the following three approaches: (1) single pulse on a static sample, (2) CRAMPS, and (3) single pulse with magic-angle spinning (MAS-only). The MAS-only results were obtained as a function of MAS speed. Although the MAS-only technique is capable of achieving a significant degree of line narrowing, even with modest MAS speeds, MAS-only spectra of the general quality of the apparently undistorted high-resolution 1H spectra obtained by the CRAMPS technique are not obtained at the highest MAS speeds examined (21 kHz for a polymethylmethacrylate sample), unless the 1H- 1H dipolar interactions in the sample are rather weak, as with silica gel or a zeolite. Thus, caution should be exercised in interpreting 1H MAS-only spectra, especially if CRAMPS results are not available as a calibration.

  7. NMR, water and plants

    International Nuclear Information System (INIS)

    As, H. van.

    1982-01-01

    This thesis describes the application of a non-destructive pulsed proton NMR method mainly to measure water transport in the xylem vessels of plant stems and in some model systems. The results are equally well applicable to liquid flow in other biological objects than plants, e.g. flow of blood and other body fluids in human and animals. The method is based on a pulse sequence of equidistant π pulses in combination with a linear magnetic field gradient. (Auth.)

  8. Solid state 13C NMR analysis of shales and coals from Laramide Basins. Final report, March 1, 1995--March 31, 1996

    Energy Technology Data Exchange (ETDEWEB)

    Miknis, F.P.; Jiao, Z.S.; Zhao, Hanqing; Surdam, R.C.

    1998-12-31

    This Western Research Institute (WRI) jointly sponsored research (JSR) project augmented and complemented research conducted by the University of Wyoming Institute For Energy Research for the Gas Research Institute. The project, {open_quotes}A New Innovative Exploitation Strategy for Gas Accumulations Within Pressure Compartments,{close_quotes} was a continuation of a project funded by the GRI Pressure Compartmentalization Program that began in 1990. That project, {open_quotes}Analysis of Pressure Chambers and Seals in the Powder River Basin, Wyoming and Montana,{close_quotes} characterized a new class of hydrocarbon traps, the discovery of which can provide an impetus to revitalize the domestic petroleum industry. In support of the UW Institute For Energy Research`s program on pressure compartmentalization, solid-state {sup 13}C NMR measurements were made on sets of shales and coals from different Laramide basins in North America. NMR measurements were made on samples taken from different formations and depths of burial in the Alberta, Bighorn, Denver, San Juan, Washakie, and Wind River basins. The carbon aromaticity determined by NMR was shown to increase with depth of burial and increased maturation. In general, the NMR data were in agreement with other maturational indicators, such as vitrinite reflectance, illite/smectite ratio, and production indices. NMR measurements were also obtained on residues from hydrous pyrolysis experiments on Almond and Lance Formation coals from the Washakie Basin. These data were used in conjunction with mass and elemental balance data to obtain information about the extent of carbon aromatization that occurs during artificial maturation. The data indicated that 41 and 50% of the original aliphatic carbon in the Almond and Lance coals, respectively, aromatized during hydrous pyrolysis.

  9. Microscopic structural analysis of fractured silk fibers from Bombyx mori and Samia cynthia ricini using 13C CP/MAS NMR with a 1 mm microcoil MAS NMR probehead

    KAUST Repository

    Yamauchi, Kazuo

    2010-07-01

    Conformational changes have been studied in silk fibers from the domestic silkworm Bombyx mori and a wild silkworm Samia cynthia ricini as a result of fractured by stretching. About 300 samples consisting of only the fractured regions of [1-13C]Ala or [1-13C]Gly labeled silk fibers were collected and observed by 13C CP/MAS NMR spectra. The total amount of these fractured fibers is only about 1 mg and therefore we used a home-built 1 mm microcoil MAS NMR probehead. A very small increase in the fraction of random coil was noted for the alanine regions of both silk fibroins and for the glycine region of B. mori silk fibroin. However, there is no difference in the spectra before and after fractured for the glycine region of S. c. ricini silk fibroin. Thus, the influence of fracture occurs exclusively at the Ala region for S. c. ricini. The relationship between sequence, fracture and structure is discussed. © 2010 Elsevier Inc. All rights reserved.

  10. Molecular level structural analysis of natural organic matter and of humic substances by NMR spectroscopy

    OpenAIRE

    Dr. Hertkorn, Norbert

    2007-01-01

    Natural organic matter (NOM) represents an ubiquitous, very complex mixture of organic and (a few) inorganic constituents and occurs in terrestrial, limnic and marine ecosystems. NOM plays immensely important roles in the natural world, and it is a key refractory constituent of the global carbon and other element cycles. The characterization and structural analysis of NOM, which features a substantial extent of both polydispersity and molecular heterogeneity, is most demanding with respect of...

  11. Cluster analysis and multiplet pattern recognition in two-dimensional NMR spectra

    Science.gov (United States)

    Neidig, Klaus-Peter; Saffrich, Rainer; Lorenz, Michael; Kalbitzer, Hans Robert

    A general and efficient strategy for the recognition of arbitrary multiplet patterns in two-dimensional nuclear magnetic resonance spectra has been developed. It comprises cluster analysis, feature extraction, and pattern matching techniques. The corresponding C routines embedded in the graphical environment of the program AURELIA were tested successfully on two-dimensional nuclear magnetic resonance spectra of the neuropeptide head activator and the HPr proteins of Staphylococcus aureus and Streptococcus faecalis.

  12. NMR spectroscopy using liquid crystal solvents

    CERN Document Server

    Emsley, JW

    2013-01-01

    NMR Spectroscopy using Liquid Crystal Solvents covers the importance of using a liquid crystal solvent in NMR to derive nuclear dipolar spin-spin coupling constants. This book is composed of ten chapters, and begins with a brief description of the features and benefits of liquid crystal in NMR spectroscopic analysis. The succeeding chapters deal with the mode of operation of nuclear spin Hamiltonian for partially oriented molecules and the analysis of NMR spectra of partially oriented molecules, as well as the determination of rigid molecule structure. These topics are followed by discussions

  13. NMR Fingerprints of Eucommia ulmoides Oliver

    Directory of Open Access Journals (Sweden)

    JIANG Yang-ming

    2017-12-01

    Full Text Available The 1H NMR fingerprint of Eucommia ulmoides acquired with a CPMG pulse sequence was analyzed with the complete reduction to amplitude-frequency table (CRAFT approach. The signals of target compounds were extracted without chemical separation and purification. Quantitative analysis showed that the average concentration of pinoresinol glucoside (PDG in Eucommia ulmoides got from Guiyang medical plant garden was 0.275 6% with a relative standard deviation (RSD of 1.69%. The results were consistent with those obtained by high performance liquid chromatography (average content of 0.269 6% and RSD of 0.65%. NMR fingerprint and multivariate statistical analysis also revealed that there existed significant differences between Hunan and Guizhou Eucommia ulmoides Oliver.

  14. Multicomponent analysis of fat- and water-soluble vitamins and auxiliary substances in multivitamin preparations by qNMR.

    Science.gov (United States)

    Eiff, Julia; Monakhova, Yulia B; Diehl, Bernd W K

    2015-04-01

    A nuclear magnetic resonance (NMR) spectroscopic method was tested to control 12 vitamins and accompanying substances in multivitamin preparations. The limits of detection (LODs) and limits of quantification (LOQs) varied in the 9.0-77.0 mg/kg and in the 34.5-93.5 mg/kg range, respectively. The coefficients of variation (CVs) ranged between 0.9% and 12%. The (1)H NMR spectra showed linearity for the 140-260 mg sample weight (R(2) > 0.918). The NMR spectra of multivitamin preparations showed the presence of different degradation products of ascorbic acid. The NMR method was applied to 13 different multivitamin preparations including tablets, capsules, and effervescent tablets with average recovery rates between 85% and 132%. A number of accompanying substances (citric acid, mannitol, saccharin, cyclamate, sum of steviol glycosides, and butylhydroxytoluene) were additionally identified and quantified. NMR was found to be suitable for the simultaneous qualitative measurement of water- and fat-soluble vitamins and accompanying substances and shows some promise for quantitative determination of at least 5 vitamins (B1, B3, B5, B6, and E) in multivitamin preparations.

  15. Magic angle spinning NMR below 6 K with a computational fluid dynamics analysis of fluid flow and temperature gradients.

    Science.gov (United States)

    Sesti, Erika L; Alaniva, Nicholas; Rand, Peter W; Choi, Eric J; Albert, Brice J; Saliba, Edward P; Scott, Faith J; Barnes, Alexander B

    2018-01-01

    We report magic angle spinning (MAS) up to 8.5 kHz with a sample temperature below 6 K using liquid helium as a variable temperature fluid. Cross polarization 13 C NMR spectra exhibit exquisite sensitivity with a single transient. Remarkably, 1 H saturation recovery experiments show a 1 H T 1 of 21 s with MAS below 6 K in the presence of trityl radicals in a glassy matrix. Leveraging the thermal spin polarization available at 4.2 K versus 298 K should result in 71 times higher signal intensity. Taking the 1 H longitudinal relaxation into account, signal averaging times are therefore predicted to be expedited by a factor of >500. Computer assisted design (CAD) and finite element analysis were employed in both the design and diagnostic stages of this cryogenic MAS technology development. Computational fluid dynamics (CFD) models describing temperature gradients and fluid flow are presented. The CFD models bearing and drive gas maintained at 100 K, while a colder helium variable temperature fluid stream cools the center of a zirconia rotor. Results from the CFD were used to optimize the helium exhaust path and determine the sample temperature. This novel cryogenic experimental platform will be integrated with pulsed dynamic nuclear polarization and electron decoupling to interrogate biomolecular structure within intact human cells. Copyright © 2017 Elsevier Inc. All rights reserved.

  16. Reactivity of 12-tungstophosphoric acid and its inhibitor potency toward Na+/K+-ATPase: A combined 31P NMR study, ab initio calculations and crystallographic analysis.

    Science.gov (United States)

    Bošnjaković-Pavlović, Nada; Bajuk-Bogdanović, Danica; Zakrzewska, Joanna; Yan, Zeyin; Holclajtner-Antunović, Ivanka; Gillet, Jean-Michel; Spasojević-de Biré, Anne

    2017-11-01

    Influence of 12-tungstophosphoric acid (WPA) on conversion of adenosine triphosphate (ATP) to adenosine diphosphate (ADP) in the presence of Na + /K + -ATPase was monitored by 31 P NMR spectroscopy. It was shown that WPA exhibits inhibitory effect on Na + /K + -ATPase activity. In order to study WPA reactivity and intermolecular interactions between WPA oxygen atoms and different proton donor types (D=O, N, C), we have considered data for WPA based compounds from the Cambridge Structural Database (CSD), the Crystallographic Open Database (COD) and the Inorganic Crystal Structure Database (ICSD). Binding properties of Keggin's anion in biological systems are illustrated using Protein Data Bank (PDB). This work constitutes the first determination of theoretical Bader charges on polyoxotungstate compound via the Atom In Molecule theory. An analysis of electrostatic potential maps at the molecular surface and charge of WPA, resulting from DFT calculations, suggests that the preferred protonation site corresponds to WPA bridging oxygen. These results enlightened WPA chemical reactivity and its potential biological applications such as the inhibition of the ATPase activity. Copyright © 2017 Elsevier Inc. All rights reserved.

  17. The NMR analysis of frying oil: a very reliable method for assessment of lipid oxidation

    Science.gov (United States)

    There are many analytical methods developed for the assessment of lipid oxidation. However, one of the most challenging issues in analyzing oil oxidation is that there is lack of consistency in results obtained from different analytical methods. The major reason for the inconsistency is that most me...

  18. Assessment of preparation methods for organic phosphorus analysis in phosphorus-polluted Fe/Al-rich Haihe river sediments using solution 31P-NMR.

    Directory of Open Access Journals (Sweden)

    Wenqiang Zhang

    Full Text Available Fe/Al-rich river sediments that were highly polluted with phosphorus (P were used in tests to determine the optimum preparation techniques for measuring organic P (Po using solution (31P nuclear magnetic resonance spectroscopy ((31P-NMR. The optimum pre-treatment, extraction time, sediment to solution ratio and sodium hydroxide-ethylenediaminetetraacetic acid (NaOH-EDTA extractant solution composition were determined. The total P and Po recovery rates were higher from freeze- and air-dried samples than from fresh samples. An extraction time of 16 h was adequate for extracting Po, and a shorter or longer extraction time led to lower recoveries of total P and Po, or led to the degradation of Po. An ideal P recovery rate and good-quality NMR spectra were obtained at a sediment:solution ratio of 1:10, showing that this ratio is ideal for extracting Po. An extractant solution of 0.25 M NaOH and 50 mM EDTA was found to be more appropriate than either NaOH on its own, or a more concentrated NaOH-EDTA mixture for (31P-NMR analysis, as this combination minimized interference from paramagnetic ions and was appropriate for the detected range of Po concentrations. The most appropriate preparation method for Po analysis, therefore, was to extract the freeze-dried and ground sediment sample with a 0.25 M NaOH and 50 mM EDTA solution at a sediment:solution ratio of 1:10, for 16 h, by shaking. As lyophilization of the NaOH-EDTA extracts proved to be an optimal pre-concentration method for Po analysis in the river sediment, the extract was lyophilized as soon as possible, and analyzed by (31P-NMR.

  19. General method of preparation of uniformly 13C, 15N-labeled DNA fragments for NMR analysis of DNA structures

    International Nuclear Information System (INIS)

    Rene, Brigitte; Masliah, Gregoire; Zargarian, Loussine; Mauffret, Olivier; Fermandjian, Serge

    2006-01-01

    Summary 13 C, 15 N labeling of biomolecules allows easier assignments of NMR resonances and provides a larger number of NMR parameters, which greatly improves the quality of DNA structures. However, there is no general DNA-labeling procedure, like those employed for proteins and RNAs. Here, we describe a general and widely applicable approach designed for preparation of isotopically labeled DNA fragments that can be used for NMR studies. The procedure is based on the PCR amplification of oligonucleotides in the presence of labeled deoxynucleotides triphosphates. It allows great flexibility thanks to insertion of a short DNA sequence (linker) between two repeats of DNA sequence to study. Size and sequence of the linker are designed as to create restriction sites at the junctions with DNA of interest. DNA duplex with desired sequence and size is released upon enzymatic digestion of the PCR product. The suitability of the procedure is validated through the preparation of two biological relevant DNA fragments

  20. Permeability in Rotliegend gas sandstones to gas and brine as predicted from NMR, mercury injection and image analysis

    DEFF Research Database (Denmark)

    Rosenbrand, Esther; Fabricius, Ida Lykke; Fisher, Quentin

    2015-01-01

    Permeability characterisation of low permeability, clay-rich gas sandstones is part of production forecasting and reservoir management. The physically based Kozeny (1927) equation linking permeability with porosity and pore size is derived for a porous medium with a homogeneous pore size, whereas...... the pore sizes in tight sandstones can range from nm to μm. Nuclear magnetic resonance (NMR) transverse relaxation was used to estimate a pore size distribution for 63 samples of Rotliegend sandstone. The surface relaxation parameter required to relate NMR to pore size is estimated by combination of NMR...... and mercury injection data. To estimate which pores control permeability to gas, gas permeability was calculated for each pore size increment by using the Kozeny equation. Permeability to brine is modelled by assuming a bound water layer on the mineral pore interface. The measured brine permeabilities...

  1. HR MAS1H NMR and chemometrics as useful tool to assess the geographical origin of cocoa beans - Comparison with HR1H NMR.

    Science.gov (United States)

    Marseglia, A; Acquotti, D; Consonni, R; Cagliani, L R; Palla, G; Caligiani, A

    2016-07-01

    Chocolate and cocoa-based products are among the goods with higher added value. A current trend of the cocoa market is to offer to the consumers high quality cocoa products, namely mono-origin cocoa. However, a reliable analytical method able to trace the geographical origin of cocoa is lacking. In this work we tested the capability of HR MAS 1 H NMR combined with chemometrics to assess the geographical origins of 60 fermented and dried cocoa beans of 23 different cocoa producing countries from the three major crop-growing areas (Africa, Central/South America, Asia/Oceania). Metabolic profiling was determined by HR MAS 1 H NMR directly on cocoa powder after the method optimization. The same samples were also subjected to extraction and analysis with HR 1 H NMR. HR MAS 1 H NMR, as 1 H NMR analysis, allowed the simultaneous detection of amino acids, polyalcohols, organic acids, sugars, methylxanthines, catechins. Moreover, HR MAS allows the detection of lipids, not present in the aqueous extract utilized for 1 H NMR. The data set obtained is therefore representative of all classes of cocoa compounds. Untargeted HR MAS 1 H NMR and 1 H NMR datasets were utilized as fingerprint of the samples and elaborated with multivariate statistical methods. A targeted quantitative approach of selected metabolites was possible only with HR 1 H NMR data, because HR MAS 1 H NMR does not give reliable quantitative results. All the approaches adopted showed a discrimination of the cocoa origins. HR MAS presents the advantages to obtain a very rapid picture of the samples, comprising both lipophilic and hydrophilic components, avoiding any sample manipulation. Copyright © 2016 Elsevier Ltd. All rights reserved.

  2. Magic-Angle-Spinning NMR Magnet Development: Field Analysis and Prototypes

    Science.gov (United States)

    Voccio, John; Hahn, Seungyong; Park, Dong Keun; Ling, Jiayin; Kim, Youngjae; Bascuñán, Juan; Iwasa, Yukikazu

    2013-01-01

    We are currently working on a program to complete a 1.5 T/75 mm RT bore magic-angle-spinning nuclear magnetic resonance magnet. The magic-angle-spinning magnet comprises a z-axis 0.866-T solenoid and an x-axis 1.225-T dipole, each to be wound with NbTi wire and operated at 4.2 K in persistent mode. A combination of the fields creates a 1.5-T field pointed at 54.74 degrees (magic angle) from the rotation (z) axis. In the first year of this 3-year program, we have completed magnetic analysis and design of both coils. Also, using a winding machine of our own design and fabrication, we have wound several prototype dipole coils with NbTi wire. As part of this development, we have repeatedly made successful persistent NbTi-NbTi joints with this multifilamentary NbTi wire. PMID:24058275

  3. CHAMP Tracking and Accelerometer Data Analysis Results

    Science.gov (United States)

    Lemoine, Frank G.; Luthcke, S. B.; Rowlands, D. D.; Pavlis, D. E.; Colombo, O. L.; Ray, Richard D.; Thompson, B.; Nerem, R. S.; Williams, Teresa A.; Smith, David E. (Technical Monitor)

    2002-01-01

    The CHAMP (Challenging Minisatellite Payload) mission's unique combination of sensors and orbit configuration will enable unprecedented improvements in modeling and understanding the Earth's static gravity field and its temporal variations. CHAMP is the first of two missions (GRACE (Gravity Recovery and Climate Experiment) to be launched in the later part of '01) that combine a new generation of GPS (Global Positioning System) receivers, a high precision three axis accelerometer, and star cameras for the precision attitude determination. In order to isolate the gravity signal for science investigations, it is necessary to perform a detailed reduction and analysis of the GPS and SLR tracking data in conjunction with the accelerometer and attitude data. Precision orbit determination based on the GPS and SLR (Satellite Laser Ranging) tracking data will isolate the orbit perturbations, while the accelerometer data will be used to distinguish the surface forces from those due to the geopotential (static, and time varying). In preparation for the CHAMP and GRACE missions, extensive modifications have been made to NASA/GSFC's GEODYN orbit determination software to enable the simultaneous reduction of spacecraft tracking (e.g. GPS and SLR), three axis accelerometer and precise attitude data. Several weeks of CHAMP tracking and accelerometer data have been analyzed and the results will be presented. Precision orbit determination analysis based on tracking data alone in addition to results based on the simultaneous reduction of tracking and accelerometer data will be discussed. Results from a calibration of the accelerometer will be presented along with the results from various orbit determination strategies. Gravity field modeling status and plans will be discussed.

  4. Molecular structure, vibrational, UV, NMR, hyperpolarizability, NBO and HOMO-LUMO analysis of Pteridine2,4-dione.

    Science.gov (United States)

    Prabavathi, N; Nilufer, A; Krishnakumar, V

    2012-12-01

    The FTIR and FT-Raman spectra of Pteridine2,4-dione has been recorded in the region 4000-450 and 4000-100 cm(-1), respectively. The tautomeric stability, optimized geometry, frequency and intensity of the vibrational bands of Pteridine2,4-dione were obtained by the density functional theory (DFT) using 6-311++G(d,p) basis set. The harmonic vibrational frequencies were calculated and the scaled values have been compared with experimental FTIR and FT-Raman spectra. The observed and the calculated frequencies are found to be in good agreement. The (1)H and(13)C NMR spectra chemical shifts of the molecule were also calculated using the gauge independent atomic orbital (GIAO) method. The theoretical UV-Vis spectrum of the compound using CIS method and the electronic properties, such as HOMO and LUMO energies, were performed by time-dependent DFT (TD-DFT) approach. The calculated HOMO and LUMO energies show that charge transfer occurs within molecule. The first order hyperpolarizability (β(0)) of these novel molecular system and related properties (β, α(0) and Δα) of Pteridine2,4-dione are calculated using DFT/6-311++G (d,p) method on the finite-field approach. The Mulliken charges, the values of electric dipole moment (μ) of the molecule were computed using DFT calculations. The change in electron density (ED) in the σ(*) antibonding orbitals and stabilization energies E(2) have been calculated by natural bond (NBO) analysis to give clear evidence of stabilization originating in the hyper conjugation of hydrogen-bonded interactions. Copyright © 2012 Elsevier B.V. All rights reserved.

  5. Combined analysis by GC (RI), GC-MS and 13C NMR of the supercritical fluid extract of Abies alba twigs.

    Science.gov (United States)

    Duquesnoy, Emilie; Marongiu, Bruno; Castola, Vincent; Piras, Alessandra; Porcedda, Silvia; Casanova, Joseph

    2010-12-01

    Two samples (leaves and twigs) of Abies alba Miller from Corsica were extracted using supercritical CO2 and their chemical compositions were compared with those of the essential oils obtained from the same batch of plant material. In total 45 components were identified using combined analysis by GC (RI), GC-MS and 13C NMR. It was observed that the contents of monoterpenes (mainly represented by limonene, alpha-pinene and camphene) were significantly lower in the supercritical fluid extract (SFE) than in the essential oil (EO). Conversely, the proportions of sesquiterpenes were much higher in CO2 extracts than in essential oils (around 30% vs 4%). Cis-abienol, a diterpene alcohol, was identified only in SFE, and the proportions of this constituent (7.5% and 17.3%) were determined using quantitative 13C NMR since it was under estimated using the standard conditions of GC.

  6. HPLC, NMR and MALDI-TOF MS Analysis of Condensed Tannins from Lithocarpus glaber Leaves with Potent Free Radical Scavenging Activity

    Directory of Open Access Journals (Sweden)

    Yi Ming Lin

    2008-12-01

    Full Text Available Using acid-catalyzed degradation in the presence of cysteamine, the condensed tannins from Lithocarpus glaber leaves were characterized, following thiolysis, by means of reversed-phase HPLC, 13C-NMR and matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF MS analyses. The thiolysis reaction products showed the presence of the procyanidin (PC and prodelphinidin (PD structures. The 13C-NMR spectrum revealed that the condensed tannins were comprised of PD (72.4% and PC (27.6%, and with a greater content of cis configuration rather than the trans configuration of C2–C3. The MALDI-TOF MS analysis proved the presence of PD units, and the maximum degree of polymerization (DP was an undecamer. The antioxidant activity of condensed tannins from L. glaber leaves was evaluated by using a free radical scavenging activity assay.

  7. Optical pumping and xenon NMR

    International Nuclear Information System (INIS)

    Raftery, M.D.

    1991-11-01

    Nuclear Magnetic Resonance (NMR) spectroscopy of xenon has become an important tool for investigating a wide variety of materials, especially those with high surface area. The sensitivity of its chemical shift to environment, and its chemical inertness and adsorption properties make xenon a particularly useful NMR probe. This work discusses the application of optical pumping to enhance the sensitivity of xenon NMR experiments, thereby allowing them to be used in the study of systems with lower surface area. A novel method of optically-pumping 129 Xe in low magnetic field below an NMR spectrometer and subsequent transfer of the gas to high magnetic field is described. NMR studies of the highly polarized gas adsorbed onto powdered samples with low to moderate surface areas are now possible. For instance, NMR studies of optically-pumped xenon adsorbed onto polyacrylic acid show that xenon has a large interaction with the surface. By modeling the low temperature data in terms of a sticking probability and the gas phase xenon-xenon interaction, the diffusion coefficient for xenon at the surface of the polymer is determined. The sensitivity enhancement afforded by optical pumping also allows the NMR observation of xenon thin films frozen onto the inner surfaces of different sample cells. The geometry of the thin films results in interesting line shapes that are due to the bulk magnetic susceptibility of xenon. Experiments are also described that combine optical pumping with optical detection for high sensitivity in low magnetic field to observe the quadrupoler evolution of 131 Xe spins at the surface of the pumping cells. In cells with macroscopic asymmetry, a residual quadrupolar interaction causes a splitting in the 131 Xe NMR frequencies in bare Pyrex glass cells and cells with added hydrogen

  8. 1H-NMR-based metabolic analysis of human serum reveals novel markers of myocardial energy expenditure in heart failure patients.

    Directory of Open Access Journals (Sweden)

    Zhiyong Du

    Full Text Available OBJECTIVE: Elevated myocardial energy expenditure (MEE is related with reduced left ventricular ejection fraction, and has also been documented as an independent predictor of cardiovascular mortality. However, the serum small-molecule metabolite profiles and pathophysiological mechanisms of elevated MEE in heart failure (HF are still lacking. Herein, we used 1H-NMR-based metabolomics analysis to screen for potential biomarkers of MEE in HF. METHODS: A total of 61 subjects were enrolled, including 46 patients with heart failure and 15 age-matched controls. Venous serum samples were collected from subjects after an 8-hour fast. An INOVA 600 MHz nuclear magnetic resonance spectrometer with Carr-Purcell-Melboom-Gill (CPMG pulse sequence was employed for the metabolomics analysis and MEE was calculated using colored Doppler echocardiography. Metabolomics data were processed using orthogonal signal correction and regression analysis was performed using the partial least squares method. RESULTS: The mean MEE levels of HF patients and controls were 139.61±58.18 cal/min and 61.09±23.54 cal/min, respectively. Serum metabolomics varied with MEE changed, and 3-hydroxybutyrate, acetone and succinate were significantly elevated with the increasing MEE. Importantly, these three metabolites were independent of administration of angiotensin converting enzyme inhibitor, β-receptor blockers, diuretics and statins (P>0.05. CONCLUSIONS: These results suggested that in patients with heart failure, MEE elevation was associated with significant changes in serum metabolomics profiles, especially the concentration of 3-hydroxybutyrate, acetone and succinate. These compounds could be used as potential serum biomarkers to study myocardial energy mechanism in HF patients.

  9. Method development in quantitative NMR towards metrologically traceable organic certified reference materials used as (31)P qNMR standards.

    Science.gov (United States)

    Weber, Michael; Hellriegel, Christine; Rueck, Alexander; Wuethrich, Juerg; Jenks, Peter; Obkircher, Markus

    2015-04-01

    Quantitative nuclear magnetic resonance (qNMR) spectroscopy is employed by an increasing number of analytical and industrial laboratories for the assignment of content and quantitative determination of impurities. Within the last few years, it was demonstrated that (1)H qNMR can be performed with high accuracy leading to measurement uncertainties below 1 % relative. It was even demonstrated that the combination of (1)H qNMR with metrological weighing can lead to measurement uncertainties below 0.1 % when highly pure substances are used. Although qNMR reference standards are already available as certified reference materials (CRM) providing traceability on the basis of (1)H qNMR experiments, there is an increasing demand for purity assays on phosphorylated organic compounds and metabolites requiring CRM for quantification by (31)P qNMR. Unfortunately, the number of available primary phosphorus standards is limited to a few inorganic CRM which only can be used for the analysis of water-soluble analytes but fail when organic solvents must be employed. This paper presents the concept of value assignment by (31)P qNMR measurements for the development of CRM and describes different approaches to establish traceability to primary Standard Reference Material from the National Institute of Standards and Technology (NIST SRM). Phosphonoacetic acid is analyzed as a water-soluble CRM candidate, whereas triphenyl phosphate is a good candidate for the use as qNMR reference material in organic solvents. These substances contain both nuclei, (1)H and (31)P, and the concept is to show that it is possible to indirectly quantify a potential phosphorus standard via its protons using (1)H qNMR. The same standard with its assigned purity can then be used for the quantification of an analyte via its phosphorus using (31)P qNMR. For the validation of the concept, triphenyl phosphate and phosphonoacetic acid have been used as (31)P qNMR standards to determine the purity of the analyte

  10. The influence of different diets on metabolism and atherosclerosis processes-A porcine model: Blood serum, urine and tissues 1H NMR metabolomics targeted analysis.

    Directory of Open Access Journals (Sweden)

    Adam Zabek

    Full Text Available The global epidemic of cardiovascular diseases leads to increased morbidity and mortality caused mainly by myocardial infarction and stroke. Atherosclerosis is the major pathological process behind this epidemic. We designed a novel model of atherosclerosis in swine. Briefly, the first group (11 pigs received normal pig feed (balanced diet group-BDG for 12 months, the second group (9 pigs was fed a Western high-calorie diet (unbalanced diet group-UDG for 12 months, the third group (8 pigs received a Western type high-calorie diet for 9 months later replaced by a normal diet for 3 months (regression group-RG. Clinical measurements included zoometric data, arterial blood pressure, heart rate and ultrasonographic evaluation of femoral arteries. Then, the animals were sacrificed and the blood serum, urine and skeletal muscle tissue were collected and 1H NMR based metabolomics studies with the application of fingerprinting PLS-DA and univariate analysis were done. Our results have shown that the molecular disturbances might overlap with other diseases such as onset of diabetes, sleep apnea and other obesity accompanied diseases. Moreover, we revealed that once initiated, molecular changes did not return to homeostatic equilibrium, at least for the duration of this experiment.

  11. The influence of different diets on metabolism and atherosclerosis processes—A porcine model: Blood serum, urine and tissues 1H NMR metabolomics targeted analysis

    Science.gov (United States)

    Paslawska, Urszula; Wojtowicz, Wojciech; Drozdz, Katarzyna; Polakof, Sergio; Podhorska, Marzena; Dziegiel, Piotr; Szuba, Andrzej

    2017-01-01

    The global epidemic of cardiovascular diseases leads to increased morbidity and mortality caused mainly by myocardial infarction and stroke. Atherosclerosis is the major pathological process behind this epidemic. We designed a novel model of atherosclerosis in swine. Briefly, the first group (11 pigs) received normal pig feed (balanced diet group—BDG) for 12 months, the second group (9 pigs) was fed a Western high-calorie diet (unbalanced diet group—UDG) for 12 months, the third group (8 pigs) received a Western type high-calorie diet for 9 months later replaced by a normal diet for 3 months (regression group—RG). Clinical measurements included zoometric data, arterial blood pressure, heart rate and ultrasonographic evaluation of femoral arteries. Then, the animals were sacrificed and the blood serum, urine and skeletal muscle tissue were collected and 1H NMR based metabolomics studies with the application of fingerprinting PLS-DA and univariate analysis were done. Our results have shown that the molecular disturbances might overlap with other diseases such as onset of diabetes, sleep apnea and other obesity accompanied diseases. Moreover, we revealed that once initiated, molecular changes did not return to homeostatic equilibrium, at least for the duration of this experiment. PMID:28991897

  12. Quantum mechanical, spectroscopic studies (FT-IR, FT-Raman, NMR, UV) and normal coordinates analysis on 3-([2-(diaminomethyleneamino) thiazol-4-yl] methylthio)-N'-sulfamoylpropanimidamide

    Science.gov (United States)

    Muthu, S.; Uma Maheswari, J.; Sundius, Tom

    2013-05-01

    Famotidine (3-([2-(diaminomethyleneamino) thiazol-4-yl] methylthio)-N'-sulfamoylpropanimidamide) is a histamine H2-receptor antagonist that inhibits stomach acid production, and it is commonly used in the treatment of peptic ulcer disease (PUD) and gastroesophageal reflux disease (GERD/GORD). Quantum chemical calculations of the equilibrium geometry of famotidine in the ground state were carried out using density functional theory (DFT/B3LYP) with the 6-311G(d,p) basis set. In addition, harmonic vibrational frequencies, infrared intensities and Raman activities were calculated at the same level of theory. A detailed interpretation of the infrared and Raman spectrum of the drug is also reported. Theoretical simulations of the FT-IR, and FT-Raman spectra of the title compound have been calculated. Good correlations between the experimental 1H and 13C NMR chemical shifts and calculated GIAO shielding tensors were found. The results of the energy and oscillator strength calculations by time-dependent density functional theory (TD-DFT) supplement the experimental findings. Total and partial density of state (TDOS and PDOS) and also overlap population density of state (COOP or OPDOS) diagrams analysis were presented. The dipole moment, linear polarizability and first order hyperpolarizability values were also computed. The linear polarizability and first order hyperpolarizabilities of the studied molecule indicate that the compound is a good candidate for nonlinear optical materials.

  13. Quantum mechanical, spectroscopic studies (FT-IR, FT-Raman, NMR, UV) and normal coordinates analysis on 3-([2-(diaminomethyleneamino) thiazol-4-yl] methylthio)-N'-sulfamoylpropanimidamide.

    Science.gov (United States)

    Muthu, S; Uma Maheswari, J; Sundius, Tom

    2013-05-01

    Famotidine (3-([2-(diaminomethyleneamino) thiazol-4-yl] methylthio)-N'-sulfamoylpropanimidamide) is a histamine H2-receptor antagonist that inhibits stomach acid production, and it is commonly used in the treatment of peptic ulcer disease (PUD) and gastroesophageal reflux disease (GERD/GORD). Quantum chemical calculations of the equilibrium geometry of famotidine in the ground state were carried out using density functional theory (DFT/B3LYP) with the 6-311G(d,p) basis set. In addition, harmonic vibrational frequencies, infrared intensities and Raman activities were calculated at the same level of theory. A detailed interpretation of the infrared and Raman spectrum of the drug is also reported. Theoretical simulations of the FT-IR, and FT-Raman spectra of the title compound have been calculated. Good correlations between the experimental (1)H and (13)C NMR chemical shifts and calculated GIAO shielding tensors were found. The results of the energy and oscillator strength calculations by time-dependent density functional theory (TD-DFT) supplement the experimental findings. Total and partial density of state (TDOS and PDOS) and also overlap population density of state (COOP or OPDOS) diagrams analysis were presented. The dipole moment, linear polarizability and first order hyperpolarizability values were also computed. The linear polarizability and first order hyperpolarizabilities of the studied molecule indicate that the compound is a good candidate for nonlinear optical materials. Copyright © 2013 Elsevier B.V. All rights reserved.

  14. NMR in structure-based drug design.

    Science.gov (United States)

    Carneiro, Marta G; Ab, Eiso; Theisgen, Stephan; Siegal, Gregg

    2017-11-08

    NMR spectroscopy is a powerful technique that can provide valuable structural information for drug discovery endeavors. Here, we discuss the strengths (and limitations) of NMR applications to structure-based drug discovery, highlighting the different levels of resolution and throughput obtainable. Additionally, the emerging field of paramagnetic NMR in drug discovery and recent developments in approaches to speed up and automate protein-observed NMR data collection and analysis are discussed. © 2017 The Author(s). Published by Portland Press Limited on behalf of the Biochemical Society.

  15. Determining and reporting purity of organic molecules: why qNMR.

    Science.gov (United States)

    Mahajan, Shivani; Singh, Inder Pal

    2013-02-01

    Although NMR has been routinely used to determine/estimate relative number of protons for structure elucidation, it has been rarely used to determine and report the purity of organic compounds. Through this paper, we want to emphasize on routine use of quantitative NMR (qNMR) for this purpose. The results of qNMR can be routinely considered as documentation of purity much like other established methods (HPLC, elemental analysis and differential scanning calorimetry). qNMR is a fast, easy, accurate and non-destructive alternate to speed up the whole analytical process and serves the purpose of both identification and purity determination of compounds using single technique. Copyright © 2012 John Wiley & Sons, Ltd.

  16. Extraction of pinocembrin from leaves of different species of Eucalyptus and its quantitative analysis by qNMR and HPTLC.

    Science.gov (United States)

    Sarat, Isha; Choudhary, Alka; Sharma, Ram Jee; Dandia, Karthik; Marsh, Karen J; Foley, William J; Singh, Inder Pal

    2015-03-01

    Pinocembrin, a flavanone with a variety of biological activities was isolated from Eucalyptus sieberi leaves and quantified in several other Eucalyptus species using qNMR and HPTLC densitometry. The effect of different extraction procedures on the extraction of the compound from Eucalyptus sieberi was also studied. The methods were validated in terms ofselectivity, specificity, linearity, recovery, precision and repeatability.

  17. Supra-molecular structure of TGBC* phases studied by means of Deuterium NMR line-shape analysis

    Czech Academy of Sciences Publication Activity Database

    Domenici, V.; Veracini, C.A.; Hamplová, Věra; Kašpar, Miroslav

    2008-01-01

    Roč. 495, č. 11 (2008), s. 133-144 ISSN 1542-1406 Institutional research plan: CEZ:AV0Z10100520 Keywords : banana -shaped * deuterium NMR * magnetic field * rod-like * smectic * twist grain boundary Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 0.537, year: 2008

  18. Solid-state NMR of inorganic semiconductors.

    Science.gov (United States)

    Yesinowski, James P

    2012-01-01

    Studies of inorganic semiconductors by solid-state NMR vary widely in terms of the nature of the samples investigated, the techniques employed to observe the NMR signal, and the types of information obtained. Compared with the NMR of diamagnetic non-semiconducting substances, important differences often result from the presence of electron or hole carriers that are the hallmark of semiconductors, and whose theoretical interpretation can be involved. This review aims to provide a broad perspective on the topic for the non-expert by providing: (1) a basic introduction to semiconductor physical concepts relevant to NMR, including common crystal structures and the various methods of making samples; (2) discussions of the NMR spin Hamiltonian, details of some of the NMR techniques and strategies used to make measurements and theoretically predict NMR parameters, and examples of how each of the terms in the Hamiltonian has provided useful information in bulk semiconductors; (3) a discussion of the additional considerations needed to interpret the NMR of nanoscale semiconductors, with selected examples. The area of semiconductor NMR is being revitalized by this interest in nanoscale semiconductors, the great improvements in NMR detection sensitivity and resolution that have occurred, and the current interest in optical pumping and spintronics-related studies. Promising directions for future research will be noted throughout.

  19. Application of diffusion-edited and solvent suppression ¹H-NMR to the direct analysis of markers in valerian-hop liquid herbal products.

    Science.gov (United States)

    Prieto, Jose M; Mellinas-Gomez, Maria; Zloh, Mire

    2016-01-01

    The rising trend to consume herbal products for the treatment and/or prevention of minor ailments together with their chemical and pharmacological complexity means there is an urgent need to develop new approaches to their quality and stability. This work looks at the application of one-dimensional diffusion-edited (1)H-NMR spectroscopy (1D DOSY) and (1)H-NMR with suppression of the ethanol and water signals to the characterisation of quality and stability markers in multi-component herbal medicines/food supplements. The experiments were performed with commercial tinctures of Valeriana officinalis L. (valerian), expired and non-expired, as well as its combination with Hummulus lupulus L. (hops), which is one of the most popular blends of relaxant herbs. These techniques did not require purification or evaporation of components for the qualitative analysis of the mixture, but only the addition of D2 O and TSP. The best diagnostic signals were found at δ 7 ppm (H-11, valerenic acid), δ 4.2 ppm (H-1, hydroxyvalerenic acid) and δ 1.5-1.8 ppm (methyl groups in prenylated moieties, α-acids/prenylated flavones). This work concludes on the potential value of 1D DOSY (1)H-NMR to provide additional assurance of quality in complex natural mixtures. Copyright © 2016 John Wiley & Sons, Ltd.

  20. 1H-NMR-based metabolic analysis of human serum reveals novel markers of myocardial energy expenditure in heart failure patients.

    Science.gov (United States)

    Du, Zhiyong; Shen, Anna; Huang, Yuli; Su, Liang; Lai, Wenyan; Wang, Peng; Xie, Zhibing; Xie, Zhiquan; Zeng, Qingchun; Ren, Hao; Xu, Dingli

    2014-01-01

    Elevated myocardial energy expenditure (MEE) is related with reduced left ventricular ejection fraction, and has also been documented as an independent predictor of cardiovascular mortality. However, the serum small-molecule metabolite profiles and pathophysiological mechanisms of elevated MEE in heart failure (HF) are still lacking. Herein, we used 1H-NMR-based metabolomics analysis to screen for potential biomarkers of MEE in HF. A total of 61 subjects were enrolled, including 46 patients with heart failure and 15 age-matched controls. Venous serum samples were collected from subjects after an 8-hour fast. An INOVA 600 MHz nuclear magnetic resonance spectrometer with Carr-Purcell-Melboom-Gill (CPMG) pulse sequence was employed for the metabolomics analysis and MEE was calculated using colored Doppler echocardiography. Metabolomics data were processed using orthogonal signal correction and regression analysis was performed using the partial least squares method. The mean MEE levels of HF patients and controls were 139.61±58.18 cal/min and 61.09±23.54 cal/min, respectively. Serum metabolomics varied with MEE changed, and 3-hydroxybutyrate, acetone and succinate were significantly elevated with the increasing MEE. Importantly, these three metabolites were independent of administration of angiotensin converting enzyme inhibitor, β-receptor blockers, diuretics and statins (P>0.05). These results suggested that in patients with heart failure, MEE elevation was associated with significant changes in serum metabolomics profiles, especially the concentration of 3-hydroxybutyrate, acetone and succinate. These compounds could be used as potential serum biomarkers to study myocardial energy mechanism in HF patients.

  1. High resolution NMR spectroscopy of synthetic polymers in bulk

    International Nuclear Information System (INIS)

    Komorski, R.A.

    1986-01-01

    The contents of this book are: Overview of high-resolution NMR of solid polymers; High-resolution NMR of glassy amorphous polymers; Carbon-13 solid-state NMR of semicrystalline polymers; Conformational analysis of polymers of solid-state NMR; High-resolution NMR studies of oriented polymers; High-resolution solid-state NMR of protons in polymers; and Deuterium NMR of solid polymers. This work brings together the various approaches for high-resolution NMR studies of bulk polymers into one volume. Heavy emphasis is, of course, given to 13C NMR studies both above and below Tg. Standard high-power pulse and wide-line techniques are not covered

  2. An improved synthesis, spectroscopic (FT-IR, NMR) study and DFT computational analysis (IR, NMR, UV-Vis, MEP diagrams, NBO, NLO, FMO) of the 1,5-methanoazocino[4,3-b]indole core structure

    Science.gov (United States)

    Uludağ, Nesimi; Serdaroğlu, Goncagül

    2018-03-01

    This study examines the synthesis of azocino[4,3-b]indole structure, which constitutes the tetracyclic framework of uleine, dasycarpidoneand tubifolidineas well as ABDE substructure of the strychnosalkaloid family. It has been synthesized by Fischer indolization of 2 and through the cylization of 4 by 2,3-dichlor-5-6-dicyanobenzoquinone (DDQ). 1H and 1C NMR chemical shifts have been predicted with GIAO approach and the calculated chemical shifts show very good agreement with observed shifts. FT-IR spectroscopy is important for the analysis of functional groups of synthesized compounds and we also supported FT-IR vibrational analysis with computational IR analysis. The vibrational spectral analysis was performed at B3LYP level of the theory in both the gas and the water phases and it was compared with the observed IR values for the important functional groups. The DFT calculations have been conducted to determine the most stable structure of the 1,2,3,4,5,6,7-Hexahydro-1,5-methanoazocino [4,3-b] indole (5). The Frontier Molecular Orbital Analysis, quantum chemical parameters, physicochemical properties have been predicted by using the same theory of level in both gas phase and the water phase, at 631 + g** and 6311++g** basis sets. TD- DFT calculations have been performed to predict the UV- Vis spectral analysis for this synthesized molecule. The Natural Bond Orbital (NBO) analysis have been performed at B3LYP level of theory to elucidate the intra-molecular interactions such as electron delocalization and conjugative interactions. NLO calculations were conducted to obtain the electric dipole moment and polarizability of the title compound.

  3. 1D-NMR and 2D-NMR analysis of the thermal degradation products from vitrinites in relation to their natural hydrogen enrichment

    Energy Technology Data Exchange (ETDEWEB)

    Iglesias, M.J. [Area de Quimica Organica, Universidad de Almeria, Carretera de Sacramento, 04120 Almeria (Spain); Cuesta, M.J.; Suarez-Ruiz, I. [Instituto Nacional del Carbon (CSIC), Ap. Co. 73, 33080 Oviedo (Spain); Laggoun-Defarge, F. [ISTO/UMR 6113 CNRS-Universite d' Orleans, Batiment Geosciences, BP 6759, 45067, Cedex 2 (France)

    2006-08-15

    A study of coal products obtained from Gray-King pyrolysis at 550{sup o}C was carried out in order to obtain information about the chemical modifications of the huminite/vitrinite structure resulting from different processes of natural hydrogen-enrichment. The high oil yield obtained, the similarity between the infrared spectra of the generated oils and those of the parent vitrinite as well as the parallelism between the compositional data deduced for these oils and those obtained by means of Curie point pyrolysis-gas chromatography/mass spectrometry justify the use of this thermal approach. Gray-King pyrolysis is preferable to other techniques because it is possible to make an accurate mass balance, a thorough study of the solid residues and a full characterization of both the volatile and non-volatile fractions of the degradation products. From a study of selected perhydrous coals, mainly composed of the vitrinite maceral group, only in the low reflectance Jurassic coal from the Whitby (England) basin (WJVl) was the incorporation of lipoidal material evident, due to the significant contribution of long-chain alkyl aromatics in its oil. The structure of the vitrinite in the other Jurassic coals, the high reflectance sample from the Whitby basin (WJVh) and the coals from the Asturias (Spain) and Portugal basins (AJV and PGJV, respectively), is probably similar to that described for non-perhydrous vitrinites in the subbituminous coal rank. However, the presence of assimilated hydrogenated substances of a secondary nature, in particular for AJV and PGJV, hinders the cross-linking and condensation processes typical of the transit to the bituminous coal rank. In Cretaceous coals, from Teruel (Spain) and Utah (EEUU), (TCV and UCV, respectively), whose perhydrous character is mainly due to the specific hydrogenated nature of their botanical precursors, the incorporation of aliphatic structures via covalent oxygen linkages is proposed. The results obtained may be useful

  4. Conformational Analysis of a High-Mannose-Type Oligosaccharide Displaying Glucosyl Determinant Recognised by Molecular Chaperones Using NMR-Validated Molecular Dynamics Simulation.

    Science.gov (United States)

    Suzuki, Tatsuya; Kajino, Megumi; Yanaka, Saeko; Zhu, Tong; Yagi, Hirokazu; Satoh, Tadashi; Yamaguchi, Takumi; Kato, Koichi

    2017-02-16

    Exploration of the conformational spaces of flexible oligosaccharides is essential to gain deeper insights into their functional mechanisms. Here we characterised dynamic conformation of a high-mannose-type dodecasaccharide with a terminal glucose residue, a critical determinant recognised by molecular chaperones. The dodecasaccharide was prepared by our developed chemoenzymatic technique, which uses 13 C labelling and lanthanide tagging to detect conformation-dependent paramagnetic effects by NMR spectroscopy. The NMR-validated molecular dynamics simulation produced the dynamic conformational ensemble of the dodecasaccharide. This determined its spatial distribution as well as the glycosidic linkage conformation of the terminal glucose determinant. Moreover, comparison of our results with previously reported crystallographic data indicates that the chaperone binding to its target oligosaccharides involves an induced-fit mechanism. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. [Classification of Cimicifuga species based on 1H-NMR fingerprint combined with pattern recognition technique].

    Science.gov (United States)

    Shen, Li; Zhao, Yan-Yan; Xie, Hong-Ping; Liu, Wan-Hui

    2013-01-01

    The metabolomic analysis of three Cimicifuga species was performed using H-NMR spectroscopy and pattern recognition (PR) techniques. A broad range of metabolites could be detected by 'H-NMR spectroscopy without any chromatographic separation. The analysis using principal component analysis (PCA) and discriminant partial least square (DPLS) of the 1H-NMR spectrum showed a clear discrimination between C. foetida and the other two species. The major metabolites responsible for the discrimination were triterpenoid saponins and saccharides. These results indicated that the combination of 1H-NMR and PR provides a useful tool for chemotaxonomic analysis and authentification of Cimicifuga species, and could used for the quality control of plant materials.

  6. Synthesis and NMR Elucidation of Novel Pentacycloundecane ...

    African Journals Online (AJOL)

    Herein we report the synthesis and NMR elucidation of five novel pentacycloundecane (PCU)-derived short peptides as potential HIV protease inhibitors. 1H and 13C spectral analysis show major overlapping of methine resonance of the PCU 'cage' thereby making it extremely difficult to assign the NMR signals. Attachment ...

  7. NMR of lignins

    Science.gov (United States)

    John Ralph; Larry L. Landucci

    2010-01-01

    This chapter will consider the basic aspects and findings of several forms of NMR spectroscopy, including separate discussions of proton, carbon, heteronuclear, and multidimensional NMR. Enhanced focus will be on 13C NMR, because of its qualitative and quantitative importance, followed by NMR’s contributions to our understanding of lignin...

  8. An approach to the simultaneous quantitative analysis of metabolites in table wines by (1)H NMR self-constructed three-dimensional spectra.

    Science.gov (United States)

    Li, Bao Qiong; Xu, Min Li; Wang, Xue; Zhai, Hong Lin; Chen, Jing; Liu, Jin Jin

    2017-02-01

    Wine consists of several hundred components with different concentrations, including water, ethanol, glycerol, organic acids and sugars. Accurate quantification of target compounds in such complex samples is a difficult task based on conventional (1)H NMR spectra due to some challenges. In this paper, the three-dimensional spectrum was constructed firstly by simply repeating (1)H NMR spectrum itself so as to extract the features of target compounds by Tchebichef moment method. A proof-of-concept model system, the determination of five metabolites in wines was utilized to evaluate the performance of the proposed strategy. The results indicate that the proposed approach can provide accurate and reliable concentration predictions, probably the best results ever achieved using PLS and interval-PLS methods. Our novel strategy has not only good performance but also does not require laborious multi-step and subjective pretreatments. Therefore, it is expected that the proposed method could extend the application of conventional (1)H NMR. Copyright © 2016 Elsevier Ltd. All rights reserved.

  9. Ignalina NPP Safety Analysis: Models and Results

    International Nuclear Information System (INIS)

    Uspuras, E.

    1999-01-01

    Research directions, linked to safety assessment of the Ignalina NPP, of the scientific safety analysis group are presented: Thermal-hydraulic analysis of accidents and operational transients; Thermal-hydraulic assessment of Ignalina NPP Accident Localization System and other compartments; Structural analysis of plant components, piping and other parts of Main Circulation Circuit; Assessment of RBMK-1500 reactor core and other. Models and main works carried out last year are described. (author)

  10. Metabolic profiling of human lung cancer blood plasma using 1H NMR spectroscopy

    Science.gov (United States)

    Kokova, Daria; Dementeva, Natalia; Kotelnikov, Oleg; Ponomaryova, Anastasia; Cherdyntseva, Nadezhda; Kzhyshkowska, Juliya

    2017-11-01

    Lung cancer (both small cell and non-small cell) is the second most common cancer in both men and women. The article represents results of evaluating of the plasma metabolic profiles of 100 lung cancer patients and 100 controls to investigate significant metabolites using 400 MHz 1H NMR spectrometer. The results of multivariate statistical analysis show that a medium-field NMR spectrometer can obtain the data which are already sufficient for clinical metabolomics.

  11. Automated Solid Phase Extraction (SPE) LC/NMR Applied to the Structural Analysis of Extractable Compounds from a Pharmaceutical Packaging Material of Construction.

    Science.gov (United States)

    Norwood, Daniel L; Mullis, James O; Davis, Mark; Pennino, Scott; Egert, Thomas; Gonnella, Nina C

    2013-01-01

    The structural analysis (i.e., identification) of organic chemical entities leached into drug product formulations has traditionally been accomplished with techniques involving the combination of chromatography with mass spectrometry. These include gas chromatography/mass spectrometry (GC/MS) for volatile and semi-volatile compounds, and various forms of liquid chromatography/mass spectrometry (LC/MS or HPLC/MS) for semi-volatile and relatively non-volatile compounds. GC/MS and LC/MS techniques are complementary for structural analysis of leachables and potentially leachable organic compounds produced via laboratory extraction of pharmaceutical container closure/delivery system components and corresponding materials of construction. Both hyphenated analytical techniques possess the separating capability, compound specific detection attributes, and sensitivity required to effectively analyze complex mixtures of trace level organic compounds. However, hyphenated techniques based on mass spectrometry are limited by the inability to determine complete bond connectivity, the inability to distinguish between many types of structural isomers, and the inability to unambiguously determine aromatic substitution patterns. Nuclear magnetic resonance spectroscopy (NMR) does not have these limitations; hence it can serve as a complement to mass spectrometry. However, NMR technology is inherently insensitive and its ability to interface with chromatography has been historically challenging. This article describes the application of NMR coupled with liquid chromatography and automated solid phase extraction (SPE-LC/NMR) to the structural analysis of extractable organic compounds from a pharmaceutical packaging material of construction. The SPE-LC/NMR technology combined with micro-cryoprobe technology afforded the sensitivity and sample mass required for full structure elucidation. Optimization of the SPE-LC/NMR analytical method was achieved using a series of model compounds

  12. relaxGUI: a new software for fast and simple NMR relaxation data analysis and calculation of ps-ns and μs motion of proteins

    International Nuclear Information System (INIS)

    Bieri, Michael; D’Auvergne, Edward J.; Gooley, Paul R.

    2011-01-01

    Investigation of protein dynamics on the ps-ns and μs-ms timeframes provides detailed insight into the mechanisms of enzymes and the binding properties of proteins. Nuclear magnetic resonance (NMR) is an excellent tool for studying protein dynamics at atomic resolution. Analysis of relaxation data using model-free analysis can be a tedious and time consuming process, which requires good knowledge of scripting procedures. The software relaxGUI was developed for fast and simple model-free analysis and is fully integrated into the software package relax. It is written in Python and uses wxPython to build the graphical user interface (GUI) for maximum performance and multi-platform use. This software allows the analysis of NMR relaxation data with ease and the generation of publication quality graphs as well as color coded images of molecular structures. The interface is designed for simple data analysis and management. The software was tested and validated against the command line version of relax.

  13. Structural analysis of flavonoids in solution through DFT 1H NMR chemical shift calculations: Epigallocatechin, Kaempferol and Quercetin

    Science.gov (United States)

    De Souza, Leonardo A.; Tavares, Wagner M. G.; Lopes, Ana Paula M.; Soeiro, Malucia M.; De Almeida, Wagner B.

    2017-05-01

    In this work, we showed that comparison between experimental and theoretical 1H NMR chemical shift patterns, calculated using Density Functional Theory (DFT), can be used for the prediction of molecular structure of flavonoids in solution, what is experimentally accessible for gas phase (electron diffraction methods) and solid samples (X-ray diffraction). The best match between B3LYP/6-31G(d,p)-PCM 1H NMR calculations for B ring rotated structures and experimental spectra can provide information on the conformation adopted by polyphenols in solution (usually DMSO-d6, acetone-d6 as solvents), which may differ from solid state and gas phase observed structures, and also DFT optimized geometry in the vacuum.

  14. Spectroscopic [FT-IR and FT-Raman] and theoretical [UV-Visible and NMR] analysis on α-Methylstyrene by DFT calculations

    Science.gov (United States)

    Karthikeyan, N.; Joseph Prince, J.; Ramalingam, S.; Periandy, S.

    2015-05-01

    In the present research work, the FT-IR, FT-Raman and 13C and 1H NMR spectra of the α-Methylstyrene were recorded. The observed fundamental frequencies in finger print as well as functional group regions were assigned according to their uniqueness region. The Gaussian computational calculations are carried out by HF and DFT (B3LYP and B3PW91) methods with 6-31++G(d,p) and 6-311++G(d,p) basis sets and the corresponding results were tabulated. The impact of the presence of vinyl group in phenyl structure of the compound is investigated. The modified vibrational pattern of the molecule associated vinyl group was analyzed. Moreover, 13C NMR and 1H NMR were calculated by using the gauge independent atomic orbital (GIAO) method with B3LYP methods and the 6-311++G(d,p) basis set and their spectra were simulated and the chemical shifts linked to TMS were compared. A study on the electronic and optical properties; absorption wavelengths, excitation energy, dipole moment and frontier molecular orbital energies were carried out. The kubo gap of the present compound was calculated related to HOMO and LUMO energies which confirm the occurring of charge transformation between the base and ligand. Besides frontier molecular orbitals (FMO), molecular electrostatic potential (MEP) was performed. The NLO properties related to Polarizability and hyperpolarizability based on the finite-field approach were also discussed.

  15. Quantitative analysis of highly similar salvianolic acids with 1H qNMR for quality control of traditional Chinese medicinal preparation Salvianolate Lyophilized Injection.

    Science.gov (United States)

    Chen, Xialin; Guo, Yujie; Hu, Yuanjia; Yu, Boyang; Qi, Jin

    2016-05-30

    Salvianolate Lyophilized Injection (SLI), a traditional Chinese medicinal (TCM) preparation which is used to treat stroke, is composed of multiple salvianolic acids from the aqueous extracts of Salvia miltiorrhiza, and includes mainly protocatechualdehyde, rosmarinic acid, salvianolic acid B, salvianolic acid D, salvianolic acid E, diastereomer of salvianolic acid E, salvianolic acid Y, lithospermic acid and diastereomer of lithospermic acid. It is difficult to quantitatively control the quality of SLI using traditional high performance liquid chromatography due to the highly similar structure of these constituents including three pairs of diastereomers and the lack of commercial resources for most of these constituents as standards. Thus, a highly reproducible, fast, accurate and simple (1)H quantitative nuclear magnetic resonance (qNMR) method without the need for calibration curves and complex computation was established by optimizing the solvent system and acquisition parameters to simultaneously determine the nine salvianolic acids and mannitol in SLI. This method was validated and successfully used to determine 10 batches of SLI and the qNMR data were further analyzed with a vector including angle cosine and the partial least squares method for the quality control of SLI. The results indicated that qNMR can be used as a routine method for the quality control of SLI and may have potential in the quantification of diastereomers in other TCM preparations. Copyright © 2016. Published by Elsevier B.V.

  16. Strategy for NMR metabolomic analysis of urine in mouse models of obesity- from sample collection to interpretation of acquired data

    Czech Academy of Sciences Publication Activity Database

    Pelantová, Helena; Bugáňová, Martina; Anýž, J.; Železná, Blanka; Maletínská, Lenka; Novák, D.; Haluzík, M.; Kuzma, Marek

    2015-01-01

    Roč. 115, NOV 10 (2015), s. 225-235 ISSN 0731-7085 R&D Projects: GA ČR GA13-14105S; GA MŠk LO1509 Grant - others:OPPC(XE) CZ.2.16/3.1.00/24023 Institutional support: RVO:61388971 ; RVO:61388963 Keywords : NMR metabolomics * Mouse * Obesity Subject RIV: CB - Analytical Chemistry, Separation; CB - Analytical Chemistry, Separation (UOCHB-X) Impact factor: 3.169, year: 2015

  17. (1)H-NMR-based metabolomic analysis of the effect of moderate wine consumption on subjects with cardiovascular risk factors

    OpenAIRE

    Vázquez Fresno, Rosa; Llorach, Rafael; Alcaro, Francesca; Rodríguez Martínez, Miguel Ángel; Vinaixa Crevillent, Maria; Chiva Blanch, Gemma; Estruch Riba, Ramon; Correig Blanchar, Xavier; Andrés Lacueva, Ma. Cristina

    2012-01-01

    Moderate wine consumption is associated with health-promoting activities. An H-NMR-based metabolomic approach was used to identify urinary metabolomic differences of moderate wine intake in the setting of a prospective, randomized, crossover, and controlled trial. Sixty-one male volunteers with high cardiovascular risk factors followed three dietary interventions (28 days): dealcoholized red wine (RWD) (272mL/day, polyphenol control), alcoholized red wine (RWA) (272mL/day) and gin (GIN) (100m...

  18. Application of fluorine NMR for structure identification of steroids.

    Science.gov (United States)

    Ampt, Kirsten A M; Aspers, Ruud L E G; Jaeger, Martin; Geutjes, Pepijn E T J; Honing, Maarten; Wijmenga, Sybren S

    2011-05-01

    Fluorinated steroids were examined using 1D and 2D homo- and heteronuclear (19)F NMR, such as (19)F-(1) H and (19)F-(13)C. The utilization of fluorine NMR accounted for spectral simplification and resulted in a straightforward pathway for the determination of structures including the configuration of these compounds; these steroids present an illustrative example for other types of fluorinated compounds, which are increasingly encountered in drug discovery. The potential of (19)F NMR is elaborated on in detail for two compounds containing diastereotopic fluorines with different coupling patterns. The analysis of the coupling patterns and the through-space interactions resulted in the determination of the structure and configuration. Heteronuclear correlation experiments, i.e. (19)F-(1)H HETCOR, (19)F-(13)C HMQC and HMBC, and (19)F-(1)H HOESY, were applied to determine first the relative stereochemistry and then the molecular configuration at C4 and C5 of a steroidal compound bearing a fused three-membered ring with two fluorine substituents. These examples proved (19)F NMR to be a useful addition to the extensively used (1)H and (13)C NMR within structure elucidation and configuration determination of small molecules. Copyright © 2011 John Wiley & Sons, Ltd.

  19. MetAssimulo:Simulation of Realistic NMR Metabolic Profiles

    Directory of Open Access Journals (Sweden)

    De Iorio Maria

    2010-10-01

    Full Text Available Abstract Background Probing the complex fusion of genetic and environmental interactions, metabolic profiling (or metabolomics/metabonomics, the study of small molecules involved in metabolic reactions, is a rapidly expanding 'omics' field. A major technique for capturing metabolite data is 1H-NMR spectroscopy and this yields highly complex profiles that require sophisticated statistical analysis methods. However, experimental data is difficult to control and expensive to obtain. Thus data simulation is a productive route to aid algorithm development. Results MetAssimulo is a MATLAB-based package that has been developed to simulate 1H-NMR spectra of complex mixtures such as metabolic profiles. Drawing data from a metabolite standard spectral database in conjunction with concentration information input by the user or constructed automatically from the Human Metabolome Database, MetAssimulo is able to create realistic metabolic profiles containing large numbers of metabolites with a range of user-defined properties. Current features include the simulation of two groups ('case' and 'control' specified by means and standard deviations of concentrations for each metabolite. The software enables addition of spectral noise with a realistic autocorrelation structure at user controllable levels. A crucial feature of the algorithm is its ability to simulate both intra- and inter-metabolite correlations, the analysis of which is fundamental to many techniques in the field. Further, MetAssimulo is able to simulate shifts in NMR peak positions that result from matrix effects such as pH differences which are often observed in metabolic NMR spectra and pose serious challenges for statistical algorithms. Conclusions No other software is currently able to simulate NMR metabolic profiles with such complexity and flexibility. This paper describes the algorithm behind MetAssimulo and demonstrates how it can be used to simulate realistic NMR metabolic profiles with

  20. NMR spectroscopic study and DFT calculations of GIAO NMR ...

    African Journals Online (AJOL)

    1H, 13C NMR chemical shifts and 1JCH coupling constants of danon have been calculated by means of B3LYP density functional method with 6-311++G(d,p) basis set. Comparison between the experimental and the theoretical results indicates that density functional B3LYP method is able to provide satisfactory results for ...

  1. Assignment of the absolute configuration of hepatoprotective highly oxygenated triterpenoids using X-ray, ECD, NMR J-based configurational analysis and HSQC overlay experiments.

    Science.gov (United States)

    Wang, Xiaojuan; Liu, Jiabao; Pandey, Pankaj; Chen, Jiabao; Fronczek, Frank R; Parnham, Stuart; Qi, Xinzhu; Doerksen, Robert J; Ferreira, Daneel; Sun, Hua; Li, Shuai; Hamann, Mark T

    2017-12-01

    The plants of the genus Kadsura are widely distributed in China, South Korea, and Japan. Their roots and stems are traditionally used to treat blood diseases and pain. The main bioactive constituents of Kadsura longipedunculata comprise highly oxygenated triterpenoids. Schiartane-type nortriterpenoids showed anti-HIV, anti-HBV, and cytotoxic bioactivities. For such compounds, the absolute configuration influences the bioactivities, and hence its unambiguous determination is essential. In this work, the absolute configurations of three highly oxygenated schiartane-type nortriterpenoids were unequivocally assigned using X-ray, ECD, and J-based configuration analysis and HSQC overlay data. The ethanol extract of Kadsura longipedunculata Finet et Gagnep was purified by column chromatography using silica, Sephadex LH-20, and ODS as substrates. To help assign the absolute configuration of schiartane-type nortriterpenoids, X-ray diffraction analysis, ECD experiment compared to ab initio computed data, DP4+ analysis, HSQC overlay, NOESY, and J-based configuration analysis were carried out. Hetero- and homo-nuclear coupling constants were extracted from HETLOC experiments. Three new highly oxygenated triterpenoids, micrandilactone I (1), micrandilactone J (2), and 22,23-di-epi-micrandilactone J (3) were isolated. Their 2D structures were solved using NMR and HRESIMS data and their absolute configurations were elucidated using X-ray diffraction analysis, ECD experimental results compared to ab initio computed spectra, HSQC overlay, DP4+, NOESY, and J-based configuration analysis. Micrandilactone I (1) and 22,23-di-epi-micrandilactone J (3) showed moderate hepatoprotective activity against APAP-induced toxicity in HepG2 cells with cell survival rates of 53.0 and 50.2%, respectively, at 10μM (bicyclol, 49.0%), while micrandilactone J (2) was inactive. This is the first comprehensive stereochemical assignment of a non-crystalline schiartane-type nortriterpenoid like 3. This

  2. Assessment of constituents in Allium by multivariate data analysis, high-resolution α-glucosidase inhibition assay and HPLC-SPE-NMR

    DEFF Research Database (Denmark)

    Schmidt, Jeppe Secher; Nyberg, Nils; Stærk, Dan

    2014-01-01

    Bulbs and leaves of 35 Allium species and cultivars bought or collected in 2010–2012 were investigated with multivariate data analysis, high-resolution α-glucosidase inhibition assays and HPLC-HRMS-SPE-NMR with the aim of exploring the potential of Allium as a future functional food for management...... of type 2 diabetes. It was found that 30 out of 106 crude extracts showed more than 80% inhibition of the α-glucosidase enzyme at a concentration of 40 mg/mL (dry sample) or 0.4 g/mL (fresh sample). High-resolution α-glucosidase biochromatograms of these extracts allowed fast identification of three...

  3. Petrophysical properties of greensand as predicted from NMR measurements

    DEFF Research Database (Denmark)

    Hossain, Zakir; Grattoni, Carlos A.; Solymar, Mikael

    2011-01-01

    ABSTRACT: Nuclear magnetic resonance (NMR) is a useful tool in reservoir evaluation. The objective of this study is to predict petrophysical properties from NMR T2 distributions. A series of laboratory experiments including core analysis, capillary pressure measurements, NMR T2 measurements and i...

  4. NMR of geophysical drill cores with a mobile Halbach scanner

    International Nuclear Information System (INIS)

    Talnishnikh, E.

    2007-01-01

    This thesis is devoted to a mobile NMR with an improved Halbach scanner. This is a lightweight tube-shaped magnet with sensitive volume larger and a homogeneity of the magnetic field higher than the previous prototype version. The improved Halbach scanner is used for analysis of water-saturated drill cores and plugs with diameters up to 60 mm. To provide the analysis, the standard 1D technique with the CPMG sequence as well as 2D correlation experiments were successfully applied and adapted to study properties of fluid-saturated sediments. Afterwards the Halbach scanner was calibrated to fast non-destructive measurements of porosity, relaxation time distributions, and estimation of permeability. These properties can be calculated directly from the NMR data using the developed methodology. Any independent measurements of these properties with other methods are not needed. One of the main results of this work is the development of a new NMR on-line core scanner for measurements of porosity in long cylindrical and semi cylindrical drill cores. Also dedicated software was written to operate the NMR on-line core scanner. The physical background of this work is the study of the diffusion influence on transverse relaxation. The diffusion effect in the presence of internal gradients in porous media was probed by 1D and 2D experiments. The transverse relaxation time distributions obtained from 1D and from 2D experiments are comparable but different in fine details. Two new methodologies were developed based on the results of this study. First is the methodology quantifying the influence of diffusion in the internal gradients of water-saturated sediments on transverse relaxation from 2D correlation experiments. The second one is the correction of the permeability estimation from the NMR data taking in account the influence of the diffusion. Furthermore, PFG NMR technique was used to study restricted diffusion in the same kind of samples. Preliminary results are reported

  5. NMR of geophysical drill cores with a mobile Halbach scanner

    Energy Technology Data Exchange (ETDEWEB)

    Talnishnikh, E.

    2007-08-21

    This thesis is devoted to a mobile NMR with an improved Halbach scanner. This is a lightweight tube-shaped magnet with sensitive volume larger and a homogeneity of the magnetic field higher than the previous prototype version. The improved Halbach scanner is used for analysis of water-saturated drill cores and plugs with diameters up to 60 mm. To provide the analysis, the standard 1D technique with the CPMG sequence as well as 2D correlation experiments were successfully applied and adapted to study properties of fluid-saturated sediments. Afterwards the Halbach scanner was calibrated to fast non-destructive measurements of porosity, relaxation time distributions, and estimation of permeability. These properties can be calculated directly from the NMR data using the developed methodology. Any independent measurements of these properties with other methods are not needed. One of the main results of this work is the development of a new NMR on-line core scanner for measurements of porosity in long cylindrical and semi cylindrical drill cores. Also dedicated software was written to operate the NMR on-line core scanner. The physical background of this work is the study of the diffusion influence on transverse relaxation. The diffusion effect in the presence of internal gradients in porous media was probed by 1D and 2D experiments. The transverse relaxation time distributions obtained from 1D and from 2D experiments are comparable but different in fine details. Two new methodologies were developed based on the results of this study. First is the methodology quantifying the influence of diffusion in the internal gradients of water-saturated sediments on transverse relaxation from 2D correlation experiments. The second one is the correction of the permeability estimation from the NMR data taking in account the influence of the diffusion. Furthermore, PFG NMR technique was used to study restricted diffusion in the same kind of samples. Preliminary results are reported

  6. Techniques for sensitivity analysis of SYVAC results

    International Nuclear Information System (INIS)

    Prust, J.O.

    1985-05-01

    Sensitivity analysis techniques may be required to examine the sensitivity of SYVAC model predictions to the input parameter values, the subjective probability distributions assigned to the input parameters and to the relationship between dose and the probability of fatal cancers plus serious hereditary disease in the first two generations of offspring of a member of the critical group. This report mainly considers techniques for determining the sensitivity of dose and risk to the variable input parameters. The performance of a sensitivity analysis technique may be improved by decomposing the model and data into subsets for analysis, making use of existing information on sensitivity and concentrating sampling in regions the parameter space that generates high doses or risks. A number of sensitivity analysis techniques are reviewed for their application to the SYVAC model including four techniques tested in an earlier study by CAP Scientific for the SYVAC project. This report recommends the development now of a method for evaluating the derivative of dose and parameter value and extending the Kruskal-Wallis technique to test for interactions between parameters. It is also recommended that the sensitivity of the output of each sub-model of SYVAC to input parameter values should be examined. (author)

  7. Dual high-resolution inhibition profiling and HPLC-HRMS-SPE-NMR analysis for identification of α-glucosidase and radical scavenging inhibitors in Solanum americanum Mill.

    Science.gov (United States)

    Silva, Eder L; Almeida-Lafetá, Rita C; Borges, Ricardo M; Staerk, Dan

    2017-04-01

    Solanum americanum is one of the most prominent species used to treat type 2 diabetes in Guatemala. In our ongoing efforts to find antidiabetic and antioxidative compounds from natural sources, an ethyl acetate extract of this medicinal herb was investigated using dual high-resolution α-glucosidase/radical scavenging inhibition profiling. The high-resolution biochromatograms obtained by this technique were used to target subsequent structural elucidation by HPLC-HRMS-SPE-NMR analysis towards the bioactive constituents. This led to identification of 4-hydroxybenzoic acid (1) and 3-indolecarboxylic acid (6) associated with radical scavenging activity, and the amide alkaloids N-trans-p-coumaroyloctopamine (3), N-trans-p-feruloyloctopamine (4), N-trans-p-coumaroyltyramine (8) and N-trans-p-feruloyltyramine (9) correlated with α-glucosidase inhibitory activity as well as radical scavenging activity. Further analysis revealed a new lactone, methyl 5-ethyl-4-hydroxy-5-methyl-2-oxotetrahydro-2H-pyran-4-carboxylate (7) and a new steroid with a rare F ring (11). Corchorifatty acid B (12) was reported for the first time in the Solanaceae family. Their structures were elucidated by extensive use of 1D and 2D NMR spectroscopy as well as HRMS analysis. Copyright © 2017 Elsevier B.V. All rights reserved.

  8. Theoretical NMR spectroscopy of N-heterocyclic carbenes and their metal complexes

    KAUST Repository

    Falivene, Laura

    2016-12-26

    Recent theoretical analysis of the NMR properties of free N-heterocyclic carbenes (NHC) and Metal-NHC complexes has complemented experiments, allowing the establishment of structure/property relationships and the rationalization of otherwise surprising experimental results. In this review, the main conclusions from recent literature are discussed, with the aim to offer a vision of the potential of theoretical analyses of NMR properties.

  9. 1H NMR analysis of the heteroassociation of antitumor antibiotics novotrone and actinomycin D in aqueous solution

    International Nuclear Information System (INIS)

    Evstigneev, M.P.; Rozvadovskaya, A.O.; Kisurkin, D.V.; Dehvis, D.B.; Veselkov, A.N.

    2004-01-01

    The heteroassociation of antitumor antibiotics novotrone (NOV) and actinomycin D (AMD) in aqueous solution has been studied by one- and two-dimensional 1 H-NMR spectroscopy (500 MHz) in order to elucidate the molecular mechanism of the action of antibiotics in combination. It has been shown that heterocomplexes become predominant in the mixed solution at r > 12. It is concluded that aromatic antibiotics (e. g. novotrone and actinomycin D) may form energetically stable heteroassociation complexes in aqueous solution and hence affect their medical-biological activity

  10. Strategy for NMR metabolomic analysis of urine in mouse models of obesity- from sample collection to interpretation of acquired data

    Czech Academy of Sciences Publication Activity Database

    Pelantová, Helena; Bugáňová, Martina; Anýž, J.; Železná, Blanka; Maletínská, Lenka; Novák, D.; Haluzík, M.; Kuzma, Marek

    2015-01-01

    Roč. 115, NOV 10 (2015), s. 225-235 ISSN 0731-7085 R&D Projects: GA ČR GA13-14105S; GA MŠk LO1509 Grant - others:OPPC(XE) CZ.2.16/3.1.00/24023 Institutional support: RVO:61388971 ; RVO:61388963 Keywords : NMR metabolomics * Mouse * Obesity Subject RIV: CB - Analytical Chemistry, Separation; CB - Analytical Chemistry, Separation (UOCHB-X) OBOR OECD: Analytical chemistry; Analytical chemistry (UOCHB-X) Impact factor: 3.169, year: 2015

  11. Metabolic profiling based on two-dimensional J-resolved 1H NMR data and parallel factor analysis

    DEFF Research Database (Denmark)

    Yilmaz, Ali; Nyberg, Nils T; Jaroszewski, Jerzy W.

    2011-01-01

    . Two-dimensional J-resolved NMR-spectra are used in this context to resolve overlapping signals by separating the effect of J-coupling from the effect of chemical shifts. Often one-dimensional projections of these data are used as input for standard multivariate statistical methods and only...... method that fits three-way experimental data to a model whose parameters in this case reflect concentrations and individual components spectrum along the chemical shift axis and corresponding profiles along the J-coupling axis. A set of saffron samples, directly extracted with methanol-d4, were used...

  12. Practical guide for selection of1H qNMR acquisition and processing parameters confirmed by automated spectra evaluation.

    Science.gov (United States)

    Monakhova, Yulia B; Diehl, Bernd W K

    2017-11-01

    In our recent paper, a new technique for automated spectra integration and quality control of the acquired results in qNMR was developed and validated (Monakhova & Diehl, Magn. Res. Chem. 2017, doi: 10.1002/mrc.4591). The present study is focused on the influence of acquisition and postacquisition parameters on the developed automated routine in particular, and on the quantitative NMR (qNMR) results in general, which has not been undertaken previously in a systematic and automated manner. Results are presented for a number of model mixtures and authentic pharmaceutical products measured on 500- and 600-MHz NMR spectrometers. The influence of the most important acquisition (spectral width, transmitter [frequency] offset, number of scans, and time domain) and processing (size of real spectrum, deconvolution, Gaussian window multiplication, and line broadening) parameters for qNMR was automatically investigated. Moderate modification of the majority of the investigated parameters from default instrument settings within evaluated ranges does not significantly affect the trueness and precision of the qNMR. Lite Gaussian window multiplication resulted in accuracy improvement of the qNMR output and is recommended for routine measurements. In general, given that the acquisition and processing parameters were selected based on the presented guidelines, automated qNMR analysis can be employed for reproducible high-precision concentration measurements in practice. Copyright © 2017 John Wiley & Sons, Ltd.

  13. HOMO-LUMO, UV, NLO, NMR and vibrational analysis of 3-methyl-1-phenylpyrazole using FT-IR, FT-RAMAN FT-NMR spectra and HF-DFT computational methods.

    Science.gov (United States)

    Carthigayan, K; Xavier, S; Periandy, S

    2015-05-05

    In this paper, the spectral analysis of 3-methyl-1-phenylpyrazole is carried out using the FT-IR, FT Raman, FT NMR and UV-Vis spectra with the help of quantum mechanical computations using HF and density functional theories. The different conformers of the compound and their minimum energies are studied using B3LYP functional with 6-311+G (d,p) basis set and the most stable conformer with minimum energy was identified and the same conformer was used for further computations. The computed wave numbers from different methods are scaled so as to agree with the experimental values and the scaling factors are reported. All the modes of vibrations are assigned and the structure the molecule is analyzed in terms of parameters like bond length, bond angle and dihedral angle predicted by both HF and B3LYP methods with 6-311+G (d,p) and 6-311++G (d,p) basis sets. The values of dipole moment (μ), polarizability (α) and hyperpolarizability (β) of the molecule are reported, using which the non-linear property of the molecule is discussed. The HOMO-LUMO mappings are reported which reveals the different charge transfer possibilities within the molecule. The isotropic chemical shifts predicted for (1)H and (13)C atoms using gauge invariant atomic orbital (GIAO) theory show good agreement with experimental shifts. NBO analysis is carried out to picture the charge transfer between the localized bonds and lone pairs. The thermodynamic properties (heat capacity, entropy and enthalpy) at different temperatures are also calculated. Copyright © 2015 Elsevier B.V. All rights reserved.

  14. NMR-spectroscopy

    International Nuclear Information System (INIS)

    Lundin, A.G.; Fedin, Eh.I.

    1986-01-01

    Physical foundations are given and the most important areas of nuclear magnetic resonance (NMR) application in physics, chemistry, biology are described. A detailed review of the investigations conducted and the NMR applications in different science and technology fields is presented. The method basic experimental variants, including such new ones as high resolution in a solid body; rare isotope resonance; two-dimensional and multi-quantum fourier-spectroscopy; large molecule NMR; NMR tomography and NMR intrascopy etc. are considered. The instruments are briefly described. NMR is characterized as one of the most important investigation methods of the material composition, its molecular and crystal structure, visualization of the living organism and nonmetallic object inner structure

  15. Portable, Low-cost NMR with Laser-Lathe Lithography Produced

    Energy Technology Data Exchange (ETDEWEB)

    Herberg, J L; Demas, V; Malba, V; Bernhardt, A; Evans, L; Harvey, C; Chinn, S; Maxwell, R; Reimer, J; Pines, A

    2006-12-21

    Nuclear Magnetic Resonance (NMR) is unsurpassed in its ability to non-destructively probe chemical identity. Portable, low-cost NMR sensors would enable on-site identification of potentially hazardous substances, as well as the study of samples in a variety of industrial applications. Recent developments in RF microcoil construction (i.e. coils much smaller than the standard 5 mm NMR RF coils), have dramatically increased NMR sensitivity and decreased the limits-of-detection (LOD). We are using advances in laser pantographic microfabrication techniques, unique to LLNL, to produce RF microcoils for field deployable, high sensitivity NMR-based detectors. This same fabrication technique can be used to produce imaging coils for MRI as well as for standard hardware shimming or 'ex-situ' shimming of field inhomogeneities typically associated with inexpensive magnets. This paper describes a portable NMR system based on a laser-fabricated microcoil and homebuilt probe design. For testing this probe, we used a hand-held 2 kg Halbach magnet that can fit into the palm of a hand, and an RF probe with laser-fabricated microcoils. The focus of the paper is on the evaluation of the microcoils, RF probe, and first generation gradient coils. The setup of this system, initial results, sensitivity measurements, and future plans are discussed. The results, even though preliminary, are promising and provide the foundation for developing a portable, inexpensive NMR system for chemical analysis. Such a system will be ideal for chemical identification of trace substances on site.

  16. Assessment of constituents in Allium by multivariate data analysis, high-resolution α-glucosidase inhibition assay and HPLC-SPE-NMR.

    Science.gov (United States)

    Schmidt, Jeppe S; Nyberg, Nils T; Staerk, Dan

    2014-10-15

    Bulbs and leaves of 35 Allium species and cultivars bought or collected in 2010-2012 were investigated with multivariate data analysis, high-resolution α-glucosidase inhibition assays and HPLC-HRMS-SPE-NMR with the aim of exploring the potential of Allium as a future functional food for management of type 2 diabetes. It was found that 30 out of 106 crude extracts showed more than 80% inhibition of the α-glucosidase enzyme at a concentration of 40mg/mL (dry sample) or 0.4g/mL (fresh sample). High-resolution α-glucosidase biochromatograms of these extracts allowed fast identification of three analytes with α-glucosidase inhibitory activity, and subsequent HPLC-HRMS-SPE-NMR experiments allowed identification of these as N-p-coumaroyloctopamine, N-p-coumaroyltyramine, and quercetin. The distribution of these three compounds was mapped for all samples by HPLC-ESI-HRMS. Unsupervised principal component analysis of samples from 2012 indicated that a major difference between fresh material and dried material is the increased amount of quercetin, a known α-glucosidase inhibitor. Copyright © 2014 Elsevier Ltd. All rights reserved.

  17. TOTEM Physics program, analysis and results

    CERN Multimedia

    CERN. Geneva

    2013-01-01

    The published results will be quickly reviewed. The current analyses of the data taken in the joint TOTEM-CMS runs will be discussed, including forward multiplicities, jets physics, soft diffractive processes, and related cross-sections. Progress in the study of low-t elastic scattering will be presented.

  18. FTIR, FT-RAMAN, NMR, spectra, normal co-ordinate analysis, NBO, NLO and DFT calculation of N,N-diethyl-4-methylpiperazine-1-carboxamide molecule.

    Science.gov (United States)

    Muthu, S; Elamurugu Porchelvi, E

    2013-11-01

    The Fourier Transform Infrared (FT-IR) and FT-Raman of N,N-diethyl-4-methylpiperazine-1-carboxamide (NND4MC) have been recorded and analyzed. The structure of the compound was optimized and the structural characteristics were determined by density functional theory (DFT) using B3LYP method with 6-31G(d,p) and 6-311G(d,p) basis sets. The difference between the observed and scaled wavenumber values of most of the fundamentals is very small. The theoretically predicted FT-IR and FT-Raman spectra of the title molecule have been constructed. The detailed interpretation of the vibrational spectra has been carried out with aid of normal coordinate analysis (NCA) following the scaled quantum mechanical force field methodology. Stability of the molecule arising from hyperconjugative interactions and charge delocalization has been analyzed using natural bond orbital (NBO) analysis. The results show that electron density (ED) in the σ(*) and π(*) antibonding orbitals and second order delocalization energies (E2) confirm the occurrence of intramolecular charge transfer (ICT) within the molecule. The electronic dipole moment (μD) and the first hyperpolarizability (βtot) values of the investigated molecule were computed using Density Functional Theory (DFT/B3LYP) with 6-31G(d,p) and 6-311G(d,p) basis sets. The calculated results also show that the NND4MC molecule may have microscopy nonlinear optical (NLO) behavior with non zero values. Mulliken atomic charges of NND4MC were calculated. The (13)C nuclear magnetic resonance (NMR) chemical shifts of the molecule were calculated by the gauge independent atomic orbital (GIAO) method and compared with experimental results. The UV-Vis spectrum of the compound was recorded. The theoretical electronic absorption spectra have been calculated by using CIS, TD-DFT methods. A study on the electronic properties, such as HOMO and LUMO energies, molecular electrostatic potential (MEP) were also performed. Copyright © 2013 Elsevier B

  19. Quantitative analysis of Bordeaux red wine precipitates by solid-state NMR: Role of tartrates and polyphenols.

    Science.gov (United States)

    Prakash, Shipra; Iturmendi, Nerea; Grelard, Axelle; Moine, Virginie; Dufourc, Erick

    2016-05-15

    Stability of wines is of great importance in oenology matters. Quantitative estimation of dark red precipitates formed in Merlot and Cabernet Sauvignon wine from Bordeaux region for vintages 2012 and 2013 was performed during the oak barrel ageing process. Precipitates were obtained by placing wine at -4°C or 4°C for 2-6 days and monitored by periodic sampling during a one-year period. Spectroscopic identification of the main families of components present in the precipitate powder was performed with (13)C solid-state CPMAS NMR and 1D and 2D solution NMR of partially water re-solubilized precipitates. The study revealed that the amount of precipitate obtained is dependent on vintage, temperature and grape variety. Major components identified include potassium bitartrate, polyphenols, polysaccharides, organic acids and free amino acids. No evidence was found for the presence of proteins. The influence of main compounds found in the precipitates is discussed in relation to wine stability. Copyright © 2016. Published by Elsevier Ltd.

  20. The NMR probe of high-T{sub c} materials and correlated electron systems. 2. ed.

    Energy Technology Data Exchange (ETDEWEB)

    Walstedt, Russell E. [Michigan Univ., Ann Arbor, MI (United States). Dept. of Physics

    2018-03-01

    This new edition updates readers in three areas of NMR studies, namely, recent developments in high-T{sub c} materials, heavy fermion systems and actinide oxides are presented. The NMR probe has yielded a vast array of data for solid state materials, corresponding to different compounds, ionic sites, and nuclear species, as well as to a wide variety of experimental conditions. The last two parts of the book are completely new in this edition, while the first part has seen major updates. This edition features the latest developments for high-T{sub c} materials, especially the advances in the area of pseudogap studies are reviewed. An in depth overview of heavy fermion systems is presented in the second part, notably Kondo lattices, quantum critical points and unconventional superconductivity are areas of intense research recently and are covered extensively. Finally, valuable information from NMR studies with actinide oxides will be provided. Ongoing analysis and discussion of NMR data have resulted in a wealth of important insights into the physics of these exotic systems. The aims of this monograph are manifold. First, it reviews NMR methodology as it has been applied to the different studies. This is addressed to NMR practitioners and to physics laypersons alike. Next, it presents a review of NMR measurements and the wide variety of phenomena which they represent. The third phase is to recount the theoretical model calculations and other proposals which have been put forward to account for these data.

  1. A Guided Inquiry Approach to NMR Spectroscopy

    Science.gov (United States)

    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.

  2. Spectroscopic [FT-IR and FT-Raman] and theoretical [UV-Visible and NMR] analysis on α-Methylstyrene by DFT calculations.

    Science.gov (United States)

    Karthikeyan, N; Joseph Prince, J; Ramalingam, S; Periandy, S

    2015-05-15

    In the present research work, the FT-IR, FT-Raman and (13)C and (1)H NMR spectra of the α-Methylstyrene were recorded. The observed fundamental frequencies in finger print as well as functional group regions were assigned according to their uniqueness region. The Gaussian computational calculations are carried out by HF and DFT (B3LYP and B3PW91) methods with 6-31++G(d,p) and 6-311++G(d,p) basis sets and the corresponding results were tabulated. The impact of the presence of vinyl group in phenyl structure of the compound is investigated. The modified vibrational pattern of the molecule associated vinyl group was analyzed. Moreover, (13)C NMR and (1)H NMR were calculated by using the gauge independent atomic orbital (GIAO) method with B3LYP methods and the 6-311++G(d,p) basis set and their spectra were simulated and the chemical shifts linked to TMS were compared. A study on the electronic and optical properties; absorption wavelengths, excitation energy, dipole moment and frontier molecular orbital energies were carried out. The kubo gap of the present compound was calculated related to HOMO and LUMO energies which confirm the occurring of charge transformation between the base and ligand. Besides frontier molecular orbitals (FMO), molecular electrostatic potential (MEP) was performed. The NLO properties related to Polarizability and hyperpolarizability based on the finite-field approach were also discussed. Crown Copyright © 2015. Published by Elsevier B.V. All rights reserved.

  3. Integration of Microfractionation, qNMR and zebrafish screening for the in vivo bioassay-guided isolation and quantitative bioactivity analysis of natural products.

    Directory of Open Access Journals (Sweden)

    Nadine Bohni

    Full Text Available Natural products (NPs are an attractive source of chemical diversity for small-molecule drug discovery. Several challenges nevertheless persist with respect to NP discovery, including the time and effort required for bioassay-guided isolation of bioactive NPs, and the limited biomedical relevance to date of in vitro bioassays used in this context. With regard to bioassays, zebrafish have recently emerged as an effective model system for chemical biology, allowing in vivo high-content screens that are compatible with microgram amounts of compound. For the deconvolution of the complex extracts into their individual constituents, recent progress has been achieved on several fronts as analytical techniques now enable the rapid microfractionation of extracts, and microflow NMR methods have developed to the point of allowing the identification of microgram amounts of NPs. Here we combine advanced analytical methods with high-content screening in zebrafish to create an integrated platform for microgram-scale, in vivo NP discovery. We use this platform for the bioassay-guided fractionation of an East African medicinal plant, Rhynchosia viscosa, resulting in the identification of both known and novel isoflavone derivatives with anti-angiogenic and anti-inflammatory activity. Quantitative microflow NMR is used both to determine the structure of bioactive compounds and to quantify them for direct dose-response experiments at the microgram scale. The key advantages of this approach are (1 the microgram scale at which both biological and analytical experiments can be performed, (2 the speed and the rationality of the bioassay-guided fractionation - generic for NP extracts of diverse origin - that requires only limited sample-specific optimization and (3 the use of microflow NMR for quantification, enabling the identification and dose-response experiments with only tens of micrograms of each compound. This study demonstrates that a complete in vivo bioassay

  4. Integration of Microfractionation, qNMR and zebrafish screening for the in vivo bioassay-guided isolation and quantitative bioactivity analysis of natural products.

    Science.gov (United States)

    Bohni, Nadine; Cordero-Maldonado, María Lorena; Maes, Jan; Siverio-Mota, Dany; Marcourt, Laurence; Munck, Sebastian; Kamuhabwa, Appolinary R; Moshi, Mainen J; Esguerra, Camila V; de Witte, Peter A M; Crawford, Alexander D; Wolfender, Jean-Luc

    2013-01-01

    Natural products (NPs) are an attractive source of chemical diversity for small-molecule drug discovery. Several challenges nevertheless persist with respect to NP discovery, including the time and effort required for bioassay-guided isolation of bioactive NPs, and the limited biomedical relevance to date of in vitro bioassays used in this context. With regard to bioassays, zebrafish have recently emerged as an effective model system for chemical biology, allowing in vivo high-content screens that are compatible with microgram amounts of compound. For the deconvolution of the complex extracts into their individual constituents, recent progress has been achieved on several fronts as analytical techniques now enable the rapid microfractionation of extracts, and microflow NMR methods have developed to the point of allowing the identification of microgram amounts of NPs. Here we combine advanced analytical methods with high-content screening in zebrafish to create an integrated platform for microgram-scale, in vivo NP discovery. We use this platform for the bioassay-guided fractionation of an East African medicinal plant, Rhynchosia viscosa, resulting in the identification of both known and novel isoflavone derivatives with anti-angiogenic and anti-inflammatory activity. Quantitative microflow NMR is used both to determine the structure of bioactive compounds and to quantify them for direct dose-response experiments at the microgram scale. The key advantages of this approach are (1) the microgram scale at which both biological and analytical experiments can be performed, (2) the speed and the rationality of the bioassay-guided fractionation - generic for NP extracts of diverse origin - that requires only limited sample-specific optimization and (3) the use of microflow NMR for quantification, enabling the identification and dose-response experiments with only tens of micrograms of each compound. This study demonstrates that a complete in vivo bioassay

  5. Analysis of cytochrome P450 CYP119 ligand-dependent conformational dynamics by two-dimensional NMR and X-ray crystallography.

    Science.gov (United States)

    Basudhar, Debashree; Madrona, Yarrow; Kandel, Sylvie; Lampe, Jed N; Nishida, Clinton R; de Montellano, Paul R Ortiz

    2015-04-17

    Defining the conformational states of cytochrome P450 active sites is critical for the design of agents that minimize drug-drug interactions, the development of isoform-specific P450 inhibitors, and the engineering of novel oxidative catalysts. We used two-dimensional (1)H,(15)N HSQC chemical shift perturbation mapping of (15)N-labeled Phe residues and x-ray crystallography to examine the ligand-dependent conformational dynamics of CYP119. Active site Phe residues were most affected by the binding of azole inhibitors and fatty acid substrates, in agreement with active site localization of the conformational changes. This was supported by crystallography, which revealed movement of the F-G loop with various azoles. Nevertheless, the NMR chemical shift perturbations caused by azoles and substrates were distinguishable. The absence of significant chemical shift perturbations with several azoles revealed binding of ligands to an open conformation similar to that of the ligand-free state. In contrast, 4-phenylimidazole caused pronounced NMR changes involving Phe-87, Phe-144, and Phe-153 that support the closed conformation found in the crystal structure. The same closed conformation is observed by NMR and crystallography with a para-fluoro substituent on the 4-phenylimidazole, but a para-chloro or bromo substituent engendered a second closed conformation. An open conformation is thus favored in solution with many azole ligands, but para-substituted phenylimidazoles give rise to two closed conformations that depend on the size of the para-substituent. The results suggest that ligands selectively stabilize discrete cytochrome P450 conformational states. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

  6. Characterizing source fingerprints and ageing processes in laboratory-generated secondary organic aerosols using proton-nuclear magnetic resonance (1H-NMR) analysis and HPLC HULIS determination

    Science.gov (United States)

    Zanca, Nicola; Lambe, Andrew T.; Massoli, Paola; Paglione, Marco; Croasdale, David R.; Parmar, Yatish; Tagliavini, Emilio; Gilardoni, Stefania; Decesari, Stefano

    2017-09-01

    The study of secondary organic aerosol (SOA) in laboratory settings has greatly increased our knowledge of the diverse chemical processes and environmental conditions responsible for the formation of particulate matter starting from biogenic and anthropogenic volatile compounds. However, characteristics of the different experimental setups and the way they impact the composition and the timescale of formation of SOA are still subject to debate. In this study, SOA samples were generated using a potential aerosol mass (PAM) oxidation flow reactor using α-pinene, naphthalene and isoprene as precursors. The PAM reactor facilitated exploration of SOA composition over atmospherically relevant photochemical ageing timescales that are unattainable in environmental chambers. The SOA samples were analyzed using two state-of-the-art analytical techniques for SOA characterization - proton nuclear magnetic resonance (1H-NMR) spectroscopy and HPLC determination of humic-like substances (HULIS). Results were compared with previous Aerodyne aerosol mass spectrometer (AMS) measurements. The combined 1H-NMR, HPLC, and AMS datasets show that the composition of the studied SOA systems tend to converge to highly oxidized organic compounds upon prolonged OH exposures. Further, our 1H-NMR findings show that only α-pinene SOA acquires spectroscopic features comparable to those of ambient OA when exposed to at least 1 × 1012 molec OH cm-3 × s OH exposure, or multiple days of equivalent atmospheric OH oxidation. Over multiple days of equivalent OH exposure, the formation of HULIS is observed in both α-pinene SOA and in naphthalene SOA (maximum yields: 16 and 30 %, respectively, of total analyzed water-soluble organic carbon, WSOC), providing evidence of the formation of humic-like polycarboxylic acids in unseeded SOA.

  7. Stochastic models (cooperative and non-cooperative) for NMR analysis of the hetero-association of aromatic molecules in aqueous solution

    Energy Technology Data Exchange (ETDEWEB)

    Evstigneev, Maxim P. [Department of Physics, Sevastopol National Technical University, Sevastopol 99053, Crimea (Ukraine)], E-mail: max_evstigneev@mail.ru; Davies, David B. [School of Biological and Chemical Sciences, Birkbeck College, University of London, Malet Street, London WC1E 7HX (United Kingdom); Veselkov, Alexei N. [Department of Physics, Sevastopol National Technical University, Sevastopol 99053, Crimea (Ukraine)

    2006-01-25

    Stochastic cooperative (STOCH-C) and non-cooperative (STOCH-NC) models have been developed for NMR analysis of the hetero-association of aromatic compounds in solution, in order to take into account all physically meaningful association reactions of molecules in which there are no limitations on the lengths of the aggregates and complexes. These algorithmical approaches are compared with previously published basic (BASE) and generalized (GEN) analytical statistical thermodynamical models of hetero-association of biologically active aromatic molecules using the same sets of published NMR data measured under the same solution conditions (0.1 M phosphate buffer, pD = 7.1, T = 298 K). It is shown that, within experimental errors, the BASE analytical model may be used to describe molecular systems characterized by relatively small contributions of hetero-association reactions, whereas the GEN model may be applied to hetero-association reactions of any aromatic compound with different self-association properties. The STOCH-C computational algorithm enabled the effect on hetero-association of the interactions of molecules with different cooperativity parameters of self-association to be estimated for the first time and it is proposed that the algorithm for the stochastic models has great potential for detailed investigation and understanding of the interactions of aromatic molecules in solution.

  8. Stochastic models (cooperative and non-cooperative) for NMR analysis of the hetero-association of aromatic molecules in aqueous solution

    International Nuclear Information System (INIS)

    Evstigneev, Maxim P.; Davies, David B.; Veselkov, Alexei N.

    2006-01-01

    Stochastic cooperative (STOCH-C) and non-cooperative (STOCH-NC) models have been developed for NMR analysis of the hetero-association of aromatic compounds in solution, in order to take into account all physically meaningful association reactions of molecules in which there are no limitations on the lengths of the aggregates and complexes. These algorithmical approaches are compared with previously published basic (BASE) and generalized (GEN) analytical statistical thermodynamical models of hetero-association of biologically active aromatic molecules using the same sets of published NMR data measured under the same solution conditions (0.1 M phosphate buffer, pD = 7.1, T = 298 K). It is shown that, within experimental errors, the BASE analytical model may be used to describe molecular systems characterized by relatively small contributions of hetero-association reactions, whereas the GEN model may be applied to hetero-association reactions of any aromatic compound with different self-association properties. The STOCH-C computational algorithm enabled the effect on hetero-association of the interactions of molecules with different cooperativity parameters of self-association to be estimated for the first time and it is proposed that the algorithm for the stochastic models has great potential for detailed investigation and understanding of the interactions of aromatic molecules in solution

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

    DEFF Research Database (Denmark)

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

    2001-01-01

    ) = 60 +/- 6 kJ/mol and DeltaS(double dagger) = 24 +/- 6 J/mol(.)K, with DeltaG degrees = 1.3 kJ/mol at -45 degreesC. The difference in the exchange rates of the rotamers of corynantheine and dihydrocorynantheine (respectively, 350 s(-1) and 9 s(-1) at 0 degreesC) reflects the difference in the steric......H-1 NMR (400 MHz) spectra of the indole alkaloid dihydrocorynantheine recorded at room temperature show the presence of two conformers near coalescence. Low temperature H-1 NMR allowed characterization of the conformational equilibrium, which involves rotation of the 3-methoxypropenoate side chain....... Line-shape analysis yielded enthalpy of activation DeltaH(double dagger) = 71 +/- 6 kJ/mol, and entropy of activation DeltaS(double dagger) = 33 +/- 6 J/mol(.)K. The major and minor conformation contains the methyl ether group above and below the plane of the ring, respectively, as determined by low...

  10. Investigation of the spatial structure of des-Gly9-[Arg8]vasopressin by the methods of two-dimensional NMR spectroscopy and theoretical conformational analysis

    International Nuclear Information System (INIS)

    Shenderovich, M.D.; Sekatsis, I.P.; Liepin'sh, E.E.; Nikiforovich, G.V.; Papsuevich, O.S.

    1986-01-01

    An assignment of the 1 H NMR signals of des-Gly 9 -[Arg 8 ]vasopressin in dimethyl sulfoxide has been made by 2D spectroscopy. The SSCCs and temperature coefficients Δδ/Δ T have been obtained for the amide protons and the system of NOE cross-peaks in the two-dimensional NOESY spectrum has been analyzed. The most important information on the spatial structure of des-Gly 9 -[Arg 8 ]vasopressin is given by the low value of the temperature coefficient Δδ/Δ T of the Asn 5 amide proton and the NOE between the α-protons of Cys 1 and Cys 6 . It is assumed that the screening of the NH proton of the Asn 5 residue from the solvent is connected with a β-bend of the backbone in the 2-5 sequence, and the distance between the C/sup α/H atoms of the Cys 1 and Cys 6 residues does not exceed 4 A. Bearing these limitations in mind, a theoretical conformational analysis of the molecule has been made. The group of low-energy conformations of the backbone obtained has been compared with the complete set of NMR characteristics

  11. nmrML: A Community Supported Open Data Standard for the Description, Storage, and Exchange of NMR Data.

    Science.gov (United States)

    Schober, Daniel; Jacob, Daniel; Wilson, Michael; Cruz, Joseph A; Marcu, Ana; Grant, Jason R; Moing, Annick; Deborde, Catherine; de Figueiredo, Luis F; Haug, Kenneth; Rocca-Serra, Philippe; Easton, John; Ebbels, Timothy M D; Hao, Jie; Ludwig, Christian; Günther, Ulrich L; Rosato, Antonio; Klein, Matthias S; Lewis, Ian A; Luchinat, Claudio; Jones, Andrew R; Grauslys, Arturas; Larralde, Martin; Yokochi, Masashi; Kobayashi, Naohiro; Porzel, Andrea; Griffin, Julian L; Viant, Mark R; Wishart, David S; Steinbeck, Christoph; Salek, Reza M; Neumann, Steffen

    2018-01-02

    NMR is a widely used analytical technique with a growing number of repositories available. As a result, demands for a vendor-agnostic, open data format for long-term archiving of NMR data have emerged with the aim to ease and encourage sharing, comparison, and reuse of NMR data. Here we present nmrML, an open XML-based exchange and storage format for NMR spectral data. The nmrML format is intended to be fully compatible with existing NMR data for chemical, biochemical, and metabolomics experiments. nmrML can capture raw NMR data, spectral data acquisition parameters, and where available spectral metadata, such as chemical structures associated with spectral assignments. The nmrML format is compatible with pure-compound NMR data for reference spectral libraries as well as NMR data from complex biomixtures, i.e., metabolomics experiments. To facilitate format conversions, we provide nmrML converters for Bruker, JEOL and Agilent/Varian vendor formats. In addition, easy-to-use Web-based spectral viewing, processing, and spectral assignment tools that read and write nmrML have been developed. Software libraries and Web services for data validation are available for tool developers and end-users. The nmrML format has already been adopted for capturing and disseminating NMR data for small molecules by several open source data processing tools and metabolomics reference spectral libraries, e.g., serving as storage format for the MetaboLights data repository. The nmrML open access data standard has been endorsed by the Metabolomics Standards Initiative (MSI), and we here encourage user participation and feedback to increase usability and make it a successful standard.

  12. Isolation, NMR Spectral Analysis and Hydrolysis Studies of a Hepta Pyranosyl Diterpene Glycoside from Stevia rebaudiana Bertoni

    Science.gov (United States)

    Chaturvedula, Venkata Sai Prakash; Chen, Steven; Yu, Oliver; Mao, Guohong

    2013-01-01

    From the commercial extract of the leaves of Stevia rebaudiana Bertoni, a minor steviol glycoside, 13-[(2-O-β-d-glucopyranosyl-3-O-β-d-glucopyranosyl-β-d-glucopyranosyl)oxy] ent-kaur-16-en-19-oic acid-[(2-O-(3-O-β-d-glucopyranosyl-α-l-rhamnopyranosyl)-3-O-β-d-glucopyranosyl-β-d-glucopyranosyl) ester] (1); also known as rebaudioside O having seven sugar units has been isolated. Its structural characterization has been achieved by the extensive 1D (1H and 13C), and 2D NMR (COSY, HMQC, HMBC) as well as mass spectral data. Further, hydrolysis studies were performed on rebaudioside O using acid and enzymatic methods to identify aglycone and sugar residues in its structure as well as their configurations. PMID:24970189

  13. Analysis of the Cross-Linking Reaction of Lignin with Triethyl Phosphate by MALDI-TOF and 13C NMR

    Directory of Open Access Journals (Sweden)

    María Cecilia Basso

    2017-06-01

    Full Text Available The reaction of condensation and cross-linking of desulfurized kraft lignin with triethyl phosphate (TEP was explored. Catechol, a simple model of the aromatic ring of lignin, and glycerol, a model compound of the aliphatic hydroyl groups of the side chain of lignin, were employed under similar reaction conditions. Solid state cross-polarisation/magic-angle spinning (CP-MAS 13C NMR and matrix assisted laser desorption ionization time-of-flight (MALDI-TOF spectroscopy studies showed that polycondensation occurs on phenolic hydroxyl groups of lignin, as well as on aliphatic hydroxyls groups of its side chain. The reactions appear to be favoured by higher temperatures and in the presence of ammonia. Preliminary adhesion tests on wood shown good hydrophobicity properties of the surface treated with lignin-TEP-based resin. Initial application tests carried out at high temperature demonstrated as good performance as metallic coating.

  14. Direct detection of carbon and nitrogen nuclei for high-resolution analysis of intrinsically disordered proteins using NMR spectroscopy.

    Science.gov (United States)

    Gibbs, E B; Kriwacki, R W

    2018-01-16

    Nuclear magnetic resonance spectroscopy (NMR) is a powerful technique for characterizing the structural and dynamic properties of intrinsically disordered proteins and protein regions (IDPs & IDRs). However, the application of NMR to IDPs has been limited by poor chemical shift dispersion in two-dimensional (2D) 1 H- 15 N heteronuclear correlation spectra. Among the various detection schemes available for heteronuclear correlation spectroscopy, 13 C direct-detection has become a mainstay for investigations of IDPs owing to the favorable chemical shift dispersion in 2D 13 C'- 15 N correlation spectra. Recent advances in cryoprobe technology have enhanced the sensitivity for direct detection of both 13 C and 15 N resonances at high magnetic field strengths, thus prompting the development of 15 N direct-detect experiments to complement established 13 C-detection experiments. However, the application of 15 N-detection has not been widely explored for IDPs. Here we compare 1 H, 13 C, and 15 N detection schemes for a variety of 2D heteronuclear correlation spectra and evaluate their performance on the basis of resolution, chemical shift dispersion, and sensitivity. We performed experiments with a variety of disordered systems ranging in size and complexity; from a small IDR (99 amino acids), to a large low complexity IDR (185 amino acids), and finally a ∼73 kDa folded homopentameric protein that also contains disordered regions (133 amino acids/monomer). We conclude that, while requiring high sample concentration and long acquisition times, 15 N-detection often offers enhanced resolution over other detection schemes in studies of disordered protein regions with low complexity sequences. Copyright © 2018 Elsevier Inc. All rights reserved.

  15. Conformational analysis of 2,2'-arylmethylene bis(3-hydroxy-5,5-dimethyl-2-cyclohexene-1-one) by NMR and molecular modeling

    Energy Technology Data Exchange (ETDEWEB)

    Ferreira, Marcelle de S.; Figueroa-Villar, Jose D., E-mail: jdfv2009@gmail.com [Instituto Militar de Engenharia (IME), Rio de Janeiro, RJ (Brazil). Dept. de Quimica. Grupo de Medicina Quimica

    2014-05-15

    2,2'-arylmethylene bis(3-hydroxy-5,5-dimethyl-2-cyclohexene-1-ones) with para and ortho-R groups on the benzene ring were prepared and studied by nuclear magnetic resonance (NMR) and molecular modeling to determine their conformational exchanges. Experimental and calculated results indicated conformational interconversions in these compounds by rotation of benzene ring and slow movement of dimedone rings, leading to intramolecular hydrogen bond length variation. The presence of one R group at the ortho position on the benzene ring modifies conformational exchange, leading to disappearance of one intramolecular hydrogen bond and superposition of diverse NMR signals. The correlation of σ{sub p} values with chemical shifts, angles and atomic charges confirms that para-R groups electronic properties are involved in conformational exchange and chemical shift variance. These results will be used to study the interaction of these compounds with bio-molecules and their use as starting materials for design and synthesis of new bioactive agents. (author)

  16. Spectroscopic (NMR, UV, FT-IR and FT-Raman) analysis and theoretical investigation of nicotinamide N-oxide with density functional theory.

    Science.gov (United States)

    Atac, Ahmet; Karabacak, Mehmet; Kose, Etem; Karaca, Caglar

    2011-12-01

    The spectroscopic properties of the nicotinamide N-oxide (abbreviated as NANO, C(6)H(6)N(2)O(2)) were examined by FT-IR, FT-Raman, NMR and UV techniques. FT-IR and FT-Raman spectra in solid state were observed in the region 4000-400 cm(-1) and 3500-50 cm(-1), respectively. The (1)H and (13)C NMR spectra were recorded in DMSO. The UV absorption spectrum of the compound that dissolved in water was recorded in the range of 200-800 nm. The structural and spectroscopic data of the molecule in the ground state were calculated by using Density Functional Theory (DFT) employing B3LYP methods with the 6-311++G(d,p) basis set. The geometry of the molecule was fully optimized, vibrational spectra were calculated and fundamental vibrations were assigned on the basis of the total energy distribution (TED) of the vibrational modes, calculated with scaled quantum mechanics (SQM) method and PQS program. The optimized structure of compound was interpreted and compared with the reported experimental values. The observed vibrational wavenumbers, absorption wavelengths and chemical shifts were compared with calculated values. As a result, the optimized geometry and calculated spectroscopic data show a good agreement with the experimental results. Copyright © 2011 Elsevier B.V. All rights reserved.

  17. NMR reaction monitoring in flow synthesis

    Directory of Open Access Journals (Sweden)

    M. Victoria Gomez

    2017-02-01

    Full Text Available Recent advances in the use of flow chemistry with in-line and on-line analysis by NMR are presented. The use of macro- and microreactors, coupled with standard and custom made NMR probes involving microcoils, incorporated into high resolution and benchtop NMR instruments is reviewed. Some recent selected applications have been collected, including synthetic applications, the determination of the kinetic and thermodynamic parameters and reaction optimization, even in single experiments and on the μL scale. Finally, software that allows automatic reaction monitoring and optimization is discussed.

  18. A strategy for acquisition and analysis of complex natural abundance 33S solid-state NMR spectra of a disordered tetrathio transition-metal anion

    Science.gov (United States)

    Jakobsen, Hans J.; Bildsøe, Henrik; Skibsted, Jørgen; Brorson, Michael; Gor'kov, Peter; Gan, Zhehong

    2010-02-01

    A strategy, involving (i) sensitivity enhancement for the central transition (CT) by population transfer (PT) employing WURST inversion pulses to the satellite transitions (STs) in natural abundance 33S MAS NMR for two different MAS frequencies ( νr = 5.0 and 10.0 kHz) at 14.1 T and (ii) a 33S static QCPMG experiment at 19.6 T, has allowed acquisition and analysis of very complex solid-state 33S CT NMR spectra for the disordered tetrathioperrhenate anion ReS4- in [(C 2H 5) 4N][ReS 4]. This strategy of different NMR experiments combined with spectral analysis/simulations has allowed determination of precise values for two sets of quadrupole coupling parameters ( CQ and ηQ) assigned to the two different S sites for the four sulfur atoms in the ReS4- anion in the ratio S1:S2 = 1:3. These sets of CQ, ηQ values for the S1 and S2 site are quite similar and the magnitudes of the quadrupole coupling constants ( CQ = 2.2-2.5 MHz) are a factor of about three larger than observed for other tetrathiometalates A 2MS 4 (A = NH 4, Cs, Rb and M = W, Mo). In addition, the spectral analysis also leads to a determination of the chemical shift anisotropy (CSA) parameters ( δσ and ησ) for the S1 and S2 site, however, with much lower precisions (about 20% error margins) compared to those for CQ, ηQ, because the magnitudes of the two CSAs (i.e., δσ = 60-90 ppm) are about a factor of six smaller than observed for the other tetrathiometalates mentioned above. This large difference in the magnitudes of the anisotropic parameters CQ and δσ for the ReS4- anion, compared to those for the WS42- and MoS42- anions determined previously under identical experimental conditions, accounts for the increased complexity of the PT-enhanced 33S MAS spectra observed for the ReS4- anion in this study. This difference in CQ also contributes significantly to the intensity distortions observed in the outer wings of the CTs when employing PT from the STs under conditions of slow-speed MAS.

  19. A strategy for acquisition and analysis of complex natural abundance (33)S solid-state NMR spectra of a disordered tetrathio transition-metal anion.

    Science.gov (United States)

    Jakobsen, Hans J; Bildsøe, Henrik; Skibsted, Jørgen; Brorson, Michael; Gor'kov, Peter; Gan, Zhehong

    2010-02-01

    A strategy, involving (i) sensitivity enhancement for the central transition (CT) by population transfer (PT) employing WURST inversion pulses to the satellite transitions (STs) in natural abundance (33)S MAS NMR for two different MAS frequencies (nu(r)=5.0 and 10.0kHz) at 14.1T and (ii) a (33)S static QCPMG experiment at 19.6T, has allowed acquisition and analysis of very complex solid-state (33)S CT NMR spectra for the disordered tetrathioperrhenate anion ReS(4)(-) in [(C(2)H(5))(4)N][ReS(4)]. This strategy of different NMR experiments combined with spectral analysis/simulations has allowed determination of precise values for two sets of quadrupole coupling parameters (C(Q) and eta(Q)) assigned to the two different S sites for the four sulfur atoms in the ReS(4)(-) anion in the ratio S1:S2=1:3. These sets of C(Q), eta(Q) values for the S1 and S2 site are quite similar and the magnitudes of the quadrupole coupling constants (C(Q)=2.2-2.5MHz) are a factor of about three larger than observed for other tetrathiometalates A(2)MS(4) (A=NH(4), Cs, Rb and M=W, Mo). In addition, the spectral analysis also leads to a determination of the chemical shift anisotropy (CSA) parameters (delta(sigma) and eta(sigma)) for the S1 and S2 site, however, with much lower precisions (about 20% error margins) compared to those for C(Q), eta(Q), because the magnitudes of the two CSAs (i.e., delta(sigma)=60-90ppm) are about a factor of six smaller than observed for the other tetrathiometalates mentioned above. This large difference in the magnitudes of the anisotropic parameters C(Q) and delta(sigma) for the ReS(4)(-) anion, compared to those for the WS(4)(2-) and MoS(4)(2-) anions determined previously under identical experimental conditions, accounts for the increased complexity of the PT-enhanced (33)S MAS spectra observed for the ReS(4)(-) anion in this study. This difference in C(Q) also contributes significantly to the intensity distortions observed in the outer wings of the CTs when

  20. Monitoring electrochemical reactions in situ using steady-state free precession {sup 13}C NMR spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Nunes, Luiza M.S. [Instituto de Química de São Carlos, Universidade de São Paulo, Avenida Trabalhador São-Carlense 400, São Carlos, São Paulo 13560-070 (Brazil); Embrapa Instrumentação, Rua XV de Novembro 1452, São Carlos, São Paulo 13560-970 (Brazil); Moraes, Tiago B. [Embrapa Instrumentação, Rua XV de Novembro 1452, São Carlos, São Paulo 13560-970 (Brazil); Instituto de Física de São Carlos, Universidade de São Paulo, Avenida Trabalhador São-Carlense 400, São Carlos, São Paulo 13566-590 (Brazil); Barbosa, Lucio L. [Departamento de Química, Universidade Federal do Espírito Santo, Avenida Fernando Ferrari 514, Vitória, Espírito Santo 29075-910 (Brazil); Mazo, Luiz H. [Instituto de Química de São Carlos, Universidade de São Paulo, Avenida Trabalhador São-Carlense 400, São Carlos, São Paulo 13560-070 (Brazil); and others

    2014-11-19

    Highlights: • Analysis of electrochemical reaction in situ by 13C NMR spectroscopy was demonstrated. • {sup 13}C NMR signals are obtained in few minutes, using steady-state free precession (SSFP) pulse sequence. • The analysis is performed in standard NMR spectrometer. • KBDM can be an alternative to Fourier Transform to process SSFP signal. - Abstract: All attempts to use in situ{sup 13}C NMR in spectroelectrochemical studies, using static cells and unlabeled substrates, have failed due to the very long average time (several hours). In this paper, we demonstrated that steady-state free precession (SSFP) pulse sequence can enhance signal to noise ratio and reduces the average time of {sup 13}C NMR signals by more than one order of magnitude. The results showed that each {sup 13}C NMR spectrum during the electrochemical reduction of 9-chloroanthracene, in a static cell, can be acquired in eleven minutes. This short averaging time allowed the analysis of the reaction every 30 min during 3 h. The phase and truncation anomalies present in SSFP spectra were minimized using Traff apodization function and Krylov basis diagonalization method (KBDM)

  1. Study the chemical composition and biological outcomes resulting from the interaction of the hormone adrenaline with heavy elements: Infrared, Raman, electronic, 1H NMR, XRD and SEM studies

    Science.gov (United States)

    Ibrahim, Omar B.; Mohamed, Mahmoud A.; Refat, Moamen S.

    2014-01-01

    Heavy metal adrenaline complexes formed from the reaction of adrenaline with Al3+, Zn2+, Sn2+, Sb3+, Pb2+and Bi3+ ions in methanolic solvent at 60 °C. The final reaction products have been isolated and characterization using elemental analyses (% of carbon, hydrogen and nitrogen), conductivity measurements, mid infrared, Raman laser, UV-Vis, 1H NMR spectra, X-ray powder diffraction, scanning electron microscopy and energy-dispersive X-ray spectroscopy (EDX). Upon the spectroscopic, conductivity and elemental analyses, the stoichiometric reactions indicated that the data obtained refer to 1:2 (M:L) for Zn2+, Sn2+, Pb2+and Bi3+ complexes [Zn(Adr)2(Cl)2], [Sn(Adr)2]Cl2, [Pb(Adr)2](NO3)2 and [Bi(Adr)2(Cl)2]Cl, while the molar ratio 1:3 (M:L) for Al3+ and Sb3+ with formulas [Al(Adr)3](NO3)3 and [Sb(Adr)3]Cl3. The infrared and Raman laser spectra interpreted the mode of interactions which associated through the two phenolic groups of catechol moiety. The adrenaline chelates have been screened for their in vitro antibacterial activity against four bacteria, Gram-positive (Bacillus subtilis and Staphylococcus aureus) and Gram-negative (Escherichia coli and Pseudomonas aeruginosa) and two strains of fungus (Aspergillus flavus and Candida albicans). The metal chelates were shown to possess more antibacterial and antifungal activities than the free adrenaline chelate.

  2. Stereochemistry of C18 monounsaturated cork suberin acids determined by spectroscopic techniques including (1) H-NMR multiplet analysis of olefinic protons.

    Science.gov (United States)

    Santos, Sara; Graça, José

    2014-01-01

    Suberin is a biopolyester responsible for the protection of secondary plant tissues, and yet its molecular structure remains unknown. The C18:1 ω-hydroxyacid and the C18:1 α,ω-diacid are major monomers in the suberin structure, but the configuration of the double bond remains to be elucidated. To unequivocally define the configuration of the C18:1 suberin acids. Pure C18:1 ω-hydroxyacid and C18:1 α,ω-diacid, isolated from cork suberin, and two structurally very close C18:1 model compounds of known stereochemistry, methyl oleate and methyl elaidate, were analysed by NMR spectroscopy, Fourier transform infrared (FTIR) and Raman spectroscopy, and GC-MS. The GC-MS analysis showed that both acids were present in cork suberin as only one geometric isomer. The analysis of dimethyloxazoline (DMOX) and picolinyl derivatives proved the double bond position to be at C-9. The FTIR spectra were concordant with a cis-configuration for both suberin acids, but their unambiguous stereochemical assignment came from the NMR analysis: (i) the chemical shifts of the allylic (13) C carbons were shielded comparatively to the trans model compound, and (ii) the complex multiplets of the olefinic protons could be simulated only with (3) JHH and long-range (4) JHH coupling constants typical of a cis geometry. The two C18:1 suberin acids in cork are (Z)-18-hydroxyoctadec-9-enoic acid and (Z)-octadec-9-enedoic acid. Copyright © 2013 John Wiley & Sons, Ltd.

  3. Cultural Heritage Studies with Mobile NMR.

    Science.gov (United States)

    Rehorn, Christian; Blümich, Bernhard

    2018-03-30

    Nuclear Magnetic Resonance (NMR) provides in-situ information about selected isotope densities in samples and objects, while also providing contrast through rotational and translational molecular dynamics. These parameters are probed not only in magnetic resonance spectroscopy and imaging but also in nondestructive materials testing by mobile stray-field NMR whose unique perks are valuable in cultural heritage studies. We present recent progress in the analysis of cultural heritage with mobile 1H NMR stray-field sensors, for which the detection zone is outside of the NMR magnet. Prominent applications include the analysis of stratigraphies in paintings and frescoes, and the assessment of material states changing under the impact of aging, conservation and restoration. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. Solid-state 27Al and 29Si NMR investigations on Si-substituted hydrogarnets

    International Nuclear Information System (INIS)

    Rivas Mercury, J.M.; Pena, P.; Aza, A.H. de; Turrillas, X.; Sobrados, I.; Sanz, J.

    2007-01-01

    Partially deuterated Ca 3 Al 2 (SiO 4 ) 3-x (OH) 4x hydrates prepared by a reaction in the presence of D 2 O of synthetic tricalcium aluminate with different amounts of amorphous silica were characterized by 29 Si and 27 Al magic-angle spinning nuclear magnetic resonance (NMR) spectroscopy. The 29 Si NMR spectroscopy was used for quantifying the non-reacted silica and the resulting hydrated products. The incorporation of Si into Ca 3 Al 2 (SiO 4 ) 3-x (OH) 4x was followed by 27 Al NMR spectroscopy: Si:OH ratios were determined quantitatively from octahedral Al signals ascribed to Al(OH) 6 and Al(OSi)(OH) 5 environments. The NMR data obtained were consistent with the concentrations of the Al and Si species deduced from transmission electron microscopy energy-dispersive spectrometry and Rietveld analysis of both X-ray and neutron diffraction data

  5. Insights on the Interaction between Transthyretin and Aβ in Solution. A Saturation Transfer Difference (STD) NMR Analysis of the Role of Iododiflunisal.

    Science.gov (United States)

    Gimeno, Ana; Santos, Luis M; Alemi, Mobina; Rivas, Josep; Blasi, Daniel; Cotrina, Ellen Y; Llop, Jordi; Valencia, Gregorio; Cardoso, Isabel; Quintana, Jordi; Arsequell, Gemma; Jiménez-Barbero, Jesús

    2017-07-13

    Several strategies against Alzheimer disease (AD) are directed to target Aβ-peptides. The ability of transthyretin (TTR) to bind Aβ-peptides and the positive effect exerted by some TTR stabilizers for modulating the TTR-Aβ interaction have been previously studied. Herein, key structural features of the interaction between TTR and the Aβ(12-28) peptide (3), the essential recognition element of Aβ, have been unravelled by STD-NMR spectroscopy methods in solution. Molecular aspects related to the role of the TTR stabilizer iododiflunisal (IDIF, 5) on the TTR-Aβ complex have been also examined. The NMR results, assisted by molecular modeling protocols, have provided a structural model for the TTR-Aβ interaction, as well as for the ternary complex formed in the presence of IDIF. This basic structural information could be relevant for providing light on the mechanisms involved in the ameliorating effects of AD symptoms observed in AD/TTR ± animal models after IDIF treatment and eventually for designing new molecules toward AD therapeutic drugs.

  6. Analysis of local molecular motions of aromatic sidechains in proteins by 2D and 3D fast MAS NMR spectroscopy and quantum mechanical calculations

    Czech Academy of Sciences Publication Activity Database

    Paluch, P.; Pawlak, T.; Jeziorna, A.; Trébosc, J.; Hou, G.; Vega, A. J.; Amoureux, J. P.; Dračínský, Martin; Polenova, T.; Potrzebowski, M. J.

    2015-01-01

    Roč. 17, č. 43 (2015), s. 28789-28801 ISSN 1463-9076 R&D Projects: GA ČR GA15-11223S Institutional support: RVO:61388963 Keywords : solid-state NMR * angle spinning NMR * NMR Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 4.449, year: 2015 http://pubs.rsc.org/en/content/articlepdf/2015/cp/c5cp04475h

  7. Scalable analysis tools for sensitivity analysis and UQ (3160) results.

    Energy Technology Data Exchange (ETDEWEB)

    Karelitz, David B.; Ice, Lisa G.; Thompson, David C.; Bennett, Janine C.; Fabian, Nathan; Scott, W. Alan; Moreland, Kenneth D.

    2009-09-01

    The 9/30/2009 ASC Level 2 Scalable Analysis Tools for Sensitivity Analysis and UQ (Milestone 3160) contains feature recognition capability required by the user community for certain verification and validation tasks focused around sensitivity analysis and uncertainty quantification (UQ). These feature recognition capabilities include crater detection, characterization, and analysis from CTH simulation data; the ability to call fragment and crater identification code from within a CTH simulation; and the ability to output fragments in a geometric format that includes data values over the fragments. The feature recognition capabilities were tested extensively on sample and actual simulations. In addition, a number of stretch criteria were met including the ability to visualize CTH tracer particles and the ability to visualize output from within an S3D simulation.

  8. NMR analysis of the interaction of picornaviral proteinases Lb and 2A with their substrate eukaryotic initiation factor 4GII.

    Science.gov (United States)

    Aumayr, Martina; Fedosyuk, Sofiya; Ruzicska, Katharina; Sousa-Blin, Carla; Kontaxis, Georg; Skern, Tim

    2015-12-01

    Messenger RNA is recruited to the eukaryotic ribosome by a complex including the eukaryotic initiation factor (eIF) 4E (the cap-binding protein), the scaffold protein eIF4G and the RNA helicase eIF4A. To shut-off host-cell protein synthesis, eIF4G is cleaved during picornaviral infection by a virally encoded proteinase; the structural basis of this reaction and its stimulation by eIF4E is unclear. We have structurally and biochemically investigated the interaction of purified foot-and-mouth disease virus (FMDV) leader proteinase (Lb(pro)), human rhinovirus 2 (HRV2) 2A proteinase (2A(pro)) and coxsackievirus B4 (CVB4) 2A(pro) with purified eIF4GII, eIF4E and the eIF4GII/eIF4E complex. Using nuclear magnetic resonance (NMR), we completed (13)C/(15) N sequential backbone assignment of human eIF4GII residues 551-745 and examined their binding to murine eIF4E. eIF4GII551-745 is intrinsically unstructured and remains so when bound to eIF4E. NMR and biophysical techniques for determining stoichiometry and binding constants revealed that the papain-like Lb(pro) only forms a stable complex with eIF4GII(551-745) in the presence of eIF4E, with KD values in the low nanomolar range; Lb(pro) contacts both eIF4GII and eIF4E. Furthermore, the unrelated chymotrypsin-like 2A(pro) from HRV2 and CVB4 also build a stable complex with eIF4GII/eIF4E, but with K(D) values in the low micromolar range. The HRV2 enzyme also forms a stable complex with eIF4E; however, none of the proteinases tested complex stably with eIF4GII alone. Thus, these three picornaviral proteinases have independently evolved to establish distinct triangular heterotrimeric protein complexes that may actively target ribosomes involved in mRNA recruitment to ensure efficient host cell shut-off. © 2015 The Authors Protein Science published by Wiley Periodicals, Inc. on behalf of The Protein Society.

  9. Solid-state NMR basic principles and practice

    CERN Document Server

    Apperley, David C; Hodgkinson, Paul

    2014-01-01

    Nuclear Magnetic Resonance (NMR) has proved to be a uniquely powerful and versatile tool for analyzing and characterizing chemicals and materials of all kinds. This book focuses on the latest developments and applications for "solid-state" NMR, which has found new uses from archaeology to crystallography to biomaterials and pharmaceutical science research. The book will provide materials engineers, analytical chemists, and physicists, in and out of lab, a survey of the techniques and the essential tools of solid-state NMR, together with a practical guide on applications. In this concise introduction to the growing field of solid-state nuclear magnetic resonance spectroscopy The reader will find: * Basic NMR concepts for solids, including guidance on the spin-1/2 nuclei concept * Coverage of the quantum mechanics aspects of solid state NMR and an introduction to the concept of quadrupolar nuclei * An understanding relaxation, exchange and quantitation in NMR * An analysis and interpretation of NMR data, with e...

  10. Application of two-dimensional NMR spectroscopy and molecular dynamics simulations to the conformational analysis of oligosaccharides corresponding to the cell-wall polysaccharide of Streptococcus group A.

    Science.gov (United States)

    Kreis, U C; Varma, V; Pinto, B M

    1995-06-01

    This paper describes the use of a protocol for conformational analysis of oligosaccharide structures related to the cell-wall polysaccharide of Streptococcus group A. The polysaccharide features a branched structure with an L-rhamnopyranose (Rhap) backbone consisting of alternating alpha-(1-->2) and alpha-(1-->3) links and D-N-acetylglucosamine (GlcpNAc) residues beta-(1-->3)-connected to alternating rhamnose rings: [formula: see text] Oligomers consisting of three to six residues have been synthesized and nuclear magnetic resonance (NMR) assignments have been made. The protocol for conformational analysis of the solution structure of these oligosaccharides involves experimental and theoretical methods. Two-dimensional NMR spectroscopy methods (TOCSY, ROESY and NOESY) are utilized to obtain chemical shift data and proton-proton distances. These distances are used as constraints in 100 ps molecular dynamics simulations in water using QUANTA and CHARMm. In addition, the dynamics simulations are performed without constraints. ROE build-up curves are computed from the averaged structures of the molecular dynamics simulations using the CROSREL program and compared with the experimental curves. Thus, a refinement of the initial structure may be obtained. The alpha-(1-->2) and the beta-(1-->3) links are unambiguously defined by the observed ROE cross peaks between the A-B',A'-B and C-B,C'-B' residues, respectively. The branch-point of the trisaccharide CBA' is conformationally well-defined. Assignment of the conformation of the B-A linkage (alpha-(1-->3)) was problematic due to TOCSY relay, but could be solved by NOESY and T-ROESY techniques. A conformational model for the polysaccharide is proposed.

  11. Synthesis of highly anti-HIV active sulfated poly- and oligo-saccharides and analysis of their action mechanisms by NMR [nuclear magnetic resonance] spectroscopy

    International Nuclear Information System (INIS)

    Uryu, Toshiyuki

    1998-01-01

    We have been synthesizing sulfated polysaccharides and oligosaccharides with highly anti-HIV (human immunodeficiency virus) activities. It has been known that sulfated polysaccharides such as dextran sulfate and pentosan polysulfate have biological activities such as anticoagulant activity and recently anti-HIV activity. Curdlan sulfate having 1,3-β-linked glucan backbone had high anti-HIV activity but low anticoagulant activity. Phase I/II test for the curdlan sulfate as an AIDS (acquired immunodeficiency syndrome) drug was carried out in the United States. In this study, regioselectivity sulfatec curdlan sulfates were prepared in order to study effects of sulfate groups and conformation of curdlan sulfates. In addition, action mechanisms of curdlan sulfate as anti-AIDS drug and of heparin as an anticoagulant were examined by means of NMR spectroscopy. 1. Structure dependence of anti-HIV and anticoagulant activities of sulfated polysaccharides. Curdlan with M n 9000 was regioselectively sulfated on its hydroxyl groups at 6, 4, and 2 positions. Those were a curdlan sulfate 62S in which 100% of 6-OH, and about 50% of 2-OH was sulfated, a curdlan sulfate 42S in which 4- and 2-OH's were sulfated, and a curdlan sulfate in which 6, 4, and 2-OH's were partially sulfated. All curdlan sulfates had very high anti-HIV activities exhibited by the drug concentration of 50% inhibition of infection, i.e., EC 50 of 0.04 - 0.25 μg/mL. However, there was almost no difference in the activity among the samples. Therefore, it was revealed that the degree of sulfation and putative conformation of the curdlan sulfates but not the position of sulfate groups have large effects on the anti-HIV activity. On the other hand, the anticoagulant activity increased with increasing molecular weight of the curdlan sulfates. As a result, it is assumed that the size of reaction sites of the virus protein reacting with curdlan sulfate is different from that of the proteins related to anticoagulant

  12. Microfluidic preparation and self diffusion PFG-NMR analysis of monodisperse water-in-oil-in-water double emulsions.

    Science.gov (United States)

    Hughes, Eric; Maan, Abid Aslam; Acquistapace, Simone; Burbidge, Adam; Johns, Michael L; Gunes, Deniz Z; Clausen, Pascal; Syrbe, Axel; Hugo, Julien; Schroen, Karin; Miralles, Vincent; Atkins, Tim; Gray, Richard; Homewood, Philip; Zick, Klaus

    2013-01-01

    Monodisperse water-in-oil-in-water (WOW) double emulsions have been prepared using microfluidic glass devices designed and built primarily from off the shelf components. The systems were easy to assemble and use. They were capable of producing double emulsions with an outer droplet size from 100 to 40 μm. Depending on how the devices were operated, double emulsions containing either single or multiple water droplets could be produced. Pulsed-field gradient self-diffusion NMR experiments have been performed on the monodisperse water-in-oil-in-water double emulsions to obtain information on the inner water droplet diameter and the distribution of the water in the different phases of the double emulsion. This has been achieved by applying regularization methods to the self-diffusion data. Using these methods the stability of the double emulsions to osmotic pressure imbalance has been followed by observing the change in the size of the inner water droplets over time. Copyright © 2012 Elsevier Inc. All rights reserved.

  13. Metabolome Comparison of Transgenic and Non-transgenic Rice by Statistical Analysis of FTIR and NMR Spectra

    Directory of Open Access Journals (Sweden)

    Keykhosrow Keymanesh

    2009-06-01

    Full Text Available Modern biotechnology, based on recombinant DNA techniques, has made it possible to introduce new traits with great potential for crop improvement. However, concerns about unintended effects of gene transformation that possibly threaten environment or consumer health have persuaded scientists to set up pre-release tests on genetically modified organisms. Assessment of ‘substantial equivalence’ concept that established by comparison of genetically modified organism with a comparator with a history of safe use could be the first step of a comprehensive risk assessment. Metabolite level is the richest in performance of changes which stem from genetic or environmental factors. Since assessment of all metabolites in detail is very costly and practically impossible, statistical evaluation of processed data of grain spectroscopic values could be a time and cost effective substitution for complex chemical analysis. To investigate the ability of multivariate statistical techniques in comparison of metabolomes as well as testing a method for such comparisons with available tools, a transgenic rice in combination with its traditionally bred parent were used as test material, and the discriminant analysis were applied as supervised method and principal component analysis as unsupervised classification method on the processed data which were extracted from Fourier transform infrared spectroscopy and nuclear magnetic resonance spectral data of powdered rice and rice extraction and barley grain samples, of which the latter was considered as control. The results confirmed the capability of statistics, even with initial data processing applications in metabolome studies. Meanwhile, this study confirms that the supervised method results in more distinctive results.

  14. Exploring catalyst passivation with NMR relaxation.

    Science.gov (United States)

    Robinson, Neil; Gladden, Lynn F; D'Agostino, Carmine

    2017-10-26

    NMR relaxation has recently emerged as a novel and non-invasive tool for probing the surface dynamics of adsorbate molecules within liquid-saturated mesoporous catalysts. The elucidation of such dynamics is of particular relevance to the study and development of solvated green catalytic processes, such as the production of chemicals and fuels from bio-resources. In this paper we develop and implement a protocol using high field 1 H NMR spin-lattice relaxation as a probe of the reorientational dynamics of liquids imbibed within mesoporous oxide materials. The observed relaxation of liquids within mesoporous materials is highly sensitive to the adsorbed surface layer, giving insight into tumbling behaviour of spin-bearing chemical environments at the pore surface. As a prototypical example of relevance to liquid-phase catalytic systems, we examine the mobility of liquid methanol within a range of common catalyst supports. In particular, through the calculation and comparison of a suitable interaction parameter, we assess and quantify changes to these surface dynamics upon replacing surface hydroxyl groups with hydrophobic alkyl chains. Our results indicate that the molecular tumbling of adsorbed methanol is enhanced upon surface passivation due to the suppression of surface-adsorbate hydrogen bonding interactions, and tends towards that of the unrestricted bulk liquid. A complex analysis in which we account for the influence of changing pore structure and surface chemistry upon passivation is discussed. The results presented highlight the use of NMR spin-lattice relaxation measurements as a non-invasive probe of molecular dynamics at surfaces of interest to liquid-phase heterogeneous catalysis.

  15. 13C-NMR chemical shift databases as a quick tool to evaluate structural models of humic substances

    DEFF Research Database (Denmark)

    Nyrop Albers, Christian; Hansen, Poul Erik

    2010-01-01

    Models for humic and fulvic acids are discussed based on 13C liquid state NMR spectra combined with results from elemental analysis and titration studies. The analysis of NMR spectra is based on a full reconstruction of the NMR spectrum done with help of 13C-NMR data bases by adding up chemical...... shifts of all substructures from the proposed models. A full reconstruction makes sure that all carbons are accounted for and enables on the negative side to discuss structural elements identified from recorded spectra of humic substances that cannot be observed in the simulated spectrum. On the positive...... side missing structural elements in the models can be suggested. A number of proposed structures for humic and fulvic acids are discussed based on the above analysis....

  16. Discrimination of Aurantii Fructus Immaturus and Fructus Poniciri Trifoliatae Immaturus by Flow Injection UV Spectroscopy (FIUV) and 1H NMR using Partial Least-squares Discriminant Analysis (PLS-DA)

    Science.gov (United States)

    Two simple fingerprinting methods, flow-injection UV spectroscopy (FIUV) and 1H nuclear magnetic resonance (NMR), for discrimination of Aurantii FructusImmaturus and Fructus Poniciri TrifoliataeImmaturususing were described. Both methods were combined with partial least-squares discriminant analysis...

  17. Functional studies using NMR

    International Nuclear Information System (INIS)

    McCready, V.R.; Leach, M.O.; Sutton; Ell, P.

    1986-01-01

    The object of this book is to discuss and evaluate an area of Nuclear Magnetic Resonance which to date has been less emphasized than it might be, namely the use of NMR for functional studies. The book commences with a discussion of the areas in which the NMR techniques might be needed due to deficiencies in other techniques. The physics of NMR especially relating to functional measurement are then explained. Technical factors in producing functional images are discussed and the use of paramagnetic substances for carrying out flow studies are detailed. Particular attention is paid to specific studies in the various organs. The book ends with a survey of imaging in each organ and the relation of NMR images to other techniques such as ultrasound, nuclear medicine and X-rays

  18. Functional studies using NMR

    International Nuclear Information System (INIS)

    McCready, V.R.; Leach, M.; Ell, P.J.

    1987-01-01

    This volume is based on a series of lectures delivered at a one-day teaching symposium on functional and metabolic aspects of NMR measurements held at the Middlesex Hospital Medical School on 1st September 1985 as a part of the European Nuclear Medicine Society Congress. Currently the major emphasis in medical NMR in vivo is on its potential to image and display abnormalities in conventional radiological images, providing increased contrast between normal and abnormal tissue, improved definition of vasculature, and possibly an increased potential for differential diagnosis. Although these areas are undeniably of major importance, it is probable that NMR will continue to complement conventional measurement methods. The major potential benefits to be derived from in vivo NMR measurements are likely to arise from its use as an instrument for functional and metabolic studies in both clinical research and in the everyday management of patients. It is to this area that this volume is directed

  19. Molecular structure, spectroscopic characterization (FT-IR, FT-Raman, UV and NMR), HOMO and LUMO analysis of 3-ethynylthiophene with DFT quantum chemical calculations.

    Science.gov (United States)

    Karabacak, Mehmet; Bilgili, Sibel; Mavis, Tugba; Eskici, Mustafa; Atac, Ahmet

    2013-11-01

    In this work, FT-IR, FT-Raman, UV and NMR spectra of 3-ethynylthiophene (3-ETP, C6H4S) were carried out by using density functional theory DFT/B3LYP method with the 6-311++G(d,p), 6-311+G(d,p), 6-311G(d,p), 6-31++G(d,p), 6-31+G(d,p), 6-31G(d,p) basis sets. FT-IR and FT-Raman spectra were recorded in the regions of 3500-400cm(-1) and 3500-50cm(-1), respectively. The geometrical parameters, energies and wavenumbers were obtained and the complete assignments of fundamental vibrations were performed on the basis of the total energy distribution (TED) of the vibrational modes, calculated with scaled quantum mechanics (SQM) method and PQS program. The (1)H, (13)C and HMQC ((1)H-(13)C correlation) NMR spectra in chloroform (CDCl3) were recorded and calculated. The UV spectrum of investigated compound were recorded in the region of 200-400nm in ethanol solution. The electronic properties, such as excitation energies, absorption wavelengths, HOMO and LUMO energies were performed by DFT/B3LYP approach and the results were compared with experimental observations. The thermodynamic properties such zero-point vibrational energy, thermal energy, specific heat capacity, rotational constants, entropy, and dipole moment of the studied compound were calculated. As a result, the calculated results were compared with the observed data and found to be in good agreement. Copyright © 2013 Elsevier B.V. All rights reserved.

  20. Integrating High-Resolution and Solid-State Magic Angle Spinning NMR Spectroscopy and a Transcriptomic Analysis of Soybean Tissues in Response to Water Deficiency.

    Science.gov (United States)

    Coutinho, Isabel D; Moraes, Tiago Bueno; Mertz-Henning, Liliane Marcia; Nepomuceno, Alexandre Lima; Giordani, Willian; Marcolino-Gomes, Juliana; Santagneli, Silvia; Colnago, Luiz Alberto

    2017-11-01

    Solid-state NMR (SSNMR) spectroscopy methods provide chemical environment and ultrastructural details that are not easily accessible by other non-destructive, high-resolution spectral techniques. High-resolution magic angle spinning (HR-MAS) has been widely used to obtain the metabolic profile of a heterogeneous sample, combining the resolution enhancement provided by MAS in SSNMR with the shimming and locking procedures in liquid-state NMR. In this work, we explored the feasibility of using the HR-MAS and SSNMR techniques to identify metabolic changes in soybean leaves subjected to water-deficient conditions. Control and water-deficient soybean leaves were analysed using one-dimensional (1D) HR-MAS and SSNMR. Total RNA was extracted from the leaves for the transcriptomic analysis. The 1 H HR-MAS and CP-MAS 13 C{ 1 H} spectra of soybean leaves grown with and without water deficiency stress revealed striking differences in metabolites. A total of 30 metabolites were identified, and the impact of water deficiency on the metabolite profile of soybean leaves was to induce amino acid synthesis. High expression levels of genes required for amino acid biosynthesis were highly correlated with the compounds identified by 1 H HR-MAS. The integration of the 1 H HR-MAS and SSNMR spectra with the transcriptomic data provided a complete picture of the major changes in the metabolic profile of soybeans in response to water deficiency. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

  1. NMR: nuclear magnetic resonance imaging; IRM: imagerie par resonance magnetique

    Energy Technology Data Exchange (ETDEWEB)

    Doyon, D

    2003-07-01

    NMR has become an indispensable technique in medical imaging. Thanks to its innocuity, many informations are revealed by this technique in particular in the study of the cardiovascular system, of the pelvis, liver, breast of children and pregnant women. Thanks to its permanent improvements, NMR allows today a morphological but also a functional analysis of new domains, like the cerebral functions, the spectroscopy, the study of cerebral-spinal liquid fluxes, the diffusion and perfusion in tissues. The aim of this book is double: first to give to the reader the indispensable physical, technical and semeiological bases for the understanding of NMR, and to make a status of the most recent advances of this examination technique. This 4. edition has been fully updated in order to integrate the most recent technical advances, in particular in the head and osteo-articular domains. After an historical and technical recall, the different domains of application are presented according to a didactical scheme: description of techniques and preparation of examinations, presentation of normal results and of main pathologies. The interventional and functional NMR are the object of a more specific development. The main protocols of exploration with respect to body part and to the pathology are developed at the end of the book. (J.S.)

  2. Characterization and elimination of undesirable protein residues in plant cell walls for enhancing lignin analysis by solution-state 2D gel-NMR methods

    Science.gov (United States)

    Proteins exist in every plant cell wall. Certain protein residues interfere with lignin characterization and quantification. The current solution-state 2D-NMR technique (gel-NMR) for whole plant cell wall structural profiling provides detailed information regarding cell walls and proteins. However, ...

  3. Structural analysis of alanine tripeptide with antiparallel and parallel beta-sheet structures in relation to the analysis of mixed beta-sheet structures in Samia cynthia ricini silk protein fiber using solid-state NMR spectroscopy.

    Science.gov (United States)

    Asakura, Tetsuo; Okonogi, Michi; Nakazawa, Yasumoto; Yamauchi, Kazuo

    2006-05-10

    The structural analysis of natural protein fibers with mixed parallel and antiparallel beta-sheet structures by solid-state NMR is reported. To obtain NMR parameters that can characterize these beta-sheet structures, (13)C solid-state NMR experiments were performed on two alanine tripeptide samples: one with 100% parallel beta-sheet structure and the other with 100% antiparallel beta-sheet structure. All (13)C resonances of the tripeptides could be assigned by a comparison of the methyl (13)C resonances of Ala(3) with different [3-(13)C]Ala labeling schemes and also by a series of RFDR (radio frequency driven recoupling) spectra observed by changing mixing times. Two (13)C resonances observed for each Ala residue could be assigned to two nonequivalent molecules per unit cell. Differences in the (13)C chemical shifts and (13)C spin-lattice relaxation times (T(1)) were observed between the two beta-sheet structures. Especially, about 3 times longer T(1) values were obtained for parallel beta-sheet structure as compared to those of antiparallel beta-sheet structure, which could be explicable by the difference in the hydrogen-bond networks of both structures. This very large difference in T(1) becomes a good measure to differentiate between parallel or antiparallel beta-sheet structures. These differences in the NMR parameters found for the tripeptides may be applied to assign the parallel and antiparallel beta-sheet (13)C resonances in the asymmetric and broad methyl spectra of [3-(13)C]Ala silk protein fiber of a wild silkworm, Samia cynthia ricini.

  4. Kinetic analysis of reactions of Si-based epoxy resins by near-infrared spectroscopy, 13C NMR and soft-hard modelling.

    Science.gov (United States)

    Garrido, Mariano; Larrechi, Maria Soledad; Rius, F Xavier; Mercado, Luis Adolfo; Galià, Marina

    2007-02-05

    Soft- and hard-modelling strategy was applied to near-infrared spectroscopy data obtained from monitoring the reaction between glycidyloxydimethylphenyl silane, a silicon-based epoxy monomer, and aniline. On the basis of the pure soft-modelling approach and previous chemical knowledge, a kinetic model for the reaction was proposed. Then, multivariate curve resolution-alternating least squares optimization was carried out under a hard constraint, that compels the concentration profiles to fulfil the proposed kinetic model at each iteration of the optimization process. In this way, the concentration profiles of each species and the corresponding kinetic rate constants of the reaction, unpublished until now, were obtained. The results obtained were contrasted with 13C NMR. The joint interval test of slope and intercept for detecting bias was not significant (alpha=5%).

  5. Positional enrichment by proton analysis (PEPA). A one-dimensional {sup 1}H-NMR approach for {sup 13}C stable isotope tracer studies in metabolomics

    Energy Technology Data Exchange (ETDEWEB)

    Vinaixa, Maria; Yanes, Oscar [Department of Electronic Engineering-Universitat Rovira i Virgili, Spanish Biomedical Research Center in Diabetes and Associated Metabolic Disorders (CIBERDEM), Reus (Spain); Rodriguez, Miguel A.; Capellades, Jordi [Universitat Rovira i Virgili, Spanish Biomedical Research Center in Diabetes and Associated Metabolic Disorders (CIBERDEM), Reus (Spain); Aivio, Suvi; Stracker, Travis H. [Institute for Research in Biomedicine (IRB Barcelona), Barcelona Institute of Science and Technology (Spain); Gomez, Josep; Canyellas, Nicolau [Department of Electronic Engineering-, Universitat Rovira i Virgili, Tarragona (Spain)

    2017-03-20

    A novel metabolomics approach for NMR-based stable isotope tracer studies called PEPA is presented, and its performance validated using human cancer cells. PEPA detects the position of carbon label in isotopically enriched metabolites and quantifies fractional enrichment by indirect determination of {sup 13}C-satellite peaks using 1D-{sup 1}H-NMR spectra. In comparison with {sup 13}C-NMR, TOCSY and HSQC, PEPA improves sensitivity, accelerates the elucidation of {sup 13}C positions in labeled metabolites and the quantification of the percentage of stable isotope enrichment. Altogether, PEPA provides a novel framework for extending the high-throughput of {sup 1}H-NMR metabolic profiling to stable isotope tracing in metabolomics, facilitating and complementing the information derived from 2D-NMR experiments and expanding the range of isotopically enriched metabolites detected in cellular extracts. (copyright 2017 The Authors. Published by Wiley-VCH Verlag GmbH and Co. KGaA.)

  6. Effect of steric hindrance on carbon dioxide absorption into new amine solutions: thermodynamic and spectroscopic verification through solubility and NMR analysis.

    Science.gov (United States)

    Park, Jung-Yeon; Yoon, Sang Jun; Lee, Huen

    2003-04-15

    Acid gas absorption technology is of great importance in these days for the prevention of global warming and the resulting worldwide climate change. More efficient process design and development for the removal of acid gases has become important, together with the development of new absorbents as one of urgent areas of research in addressing global-warming problems. In the present work, aqueous solutions of 2-amino-2-hydroxymethyl-1,3-propanediol (AHPD), a sterically hindered amine, has been examined as a potential CO2 absorbent and compared with the most commonly used absorbent, monoethanolamine (MEA) solution, through equilibrium solubility measurements and 13C NMR spectroscopic analyses. The solubilities of CO2 in aqueous 10 mass % AHPD solutions were higher than those in aqueous 10 mass % MEA solutions above 4 kPa at 298.15 K, but below 4 kPa, the solubility behavior appeared to be the opposite. The solubility difference between these two solutions increased with the CO2 partial pressures above the crossover pressure. Equilibrated CO2-MEA-H2O and CO2-AHPD-H2O solutions at various CO2 partal pressures ranging from 0.01 to 3000 kPa were analyzed by 13C NMR spectroscopy to provide a more microscopic understanding of the reaction mechanisms in the two solutions. In the CO2-amine-H2O solutions, amine reacted with CO2 to form mainly the protonated amine (AMH+), bicarbonate ion (HCO3-), and carbamate anion (AMCO2-), where the quantitative ratio of bicarbonate ion to carbamate anion strongly influenced the CO2 loading in the amine solutions. A profusion of bicarbonate ions, but a very small amount of carbamate anions, was identified in the CO2-AHPD-H2O solution, whereas a considerable amount of carbamate anions was formed in the CO2-MEA-H2O solution. AHPD contains more hydroxyl groups than nonhindered MEA, and hence, the chemical shifts in its 13C NMR spectra were strongly influenced by the solution pH values. In contrast, MEA appeared to be insensitive to pH. The

  7. UC Merced NMR Instrumentation Acquisition

    Science.gov (United States)

    2015-06-18

    UC Merced NMR Instrumentation Acquisition For the UC Merced NMR Instrumentation Acquisition proposal, a new 400 MHz and an upgraded 500 MHz NMR...valid OMB control number. PLEASE DO NOT RETURN YOUR FORM TO THE ABOVE ADDRESS. University of California - Merced 5200 North Lake Road Merced , CA 95343...UC Merced NMR Instrumentation Acquisition Report Title For the UC Merced NMR Instrumentation Acquisition proposal, a new 400 MHz and an upgraded 500

  8. Performance of the WeNMR CS-Rosetta3 web server in CASD-NMR.

    Science.gov (United States)

    van der Schot, Gijs; Bonvin, Alexandre M J J

    2015-08-01

    We present here the performance of the WeNMR CS-Rosetta3 web server in CASD-NMR, the critical assessment of automated structure determination by NMR. The CS-Rosetta server uses only chemical shifts for structure prediction, in combination, when available, with a post-scoring procedure based on unassigned NOE lists (Huang et al. in J Am Chem Soc 127:1665-1674, 2005b, doi: 10.1021/ja047109h). We compare the original submissions using a previous version of the server based on Rosetta version 2.6 with recalculated targets using the new R3FP fragment picker for fragment selection and implementing a new annotation of prediction reliability (van der Schot et al. in J Biomol NMR 57:27-35, 2013, doi: 10.1007/s10858-013-9762-6), both implemented in the CS-Rosetta3 WeNMR server. In this second round of CASD-NMR, the WeNMR CS-Rosetta server has demonstrated a much better performance than in the first round since only converged targets were submitted. Further, recalculation of all CASD-NMR targets using the new version of the server demonstrates that our new annotation of prediction quality is giving reliable results. Predictions annotated as weak are often found to provide useful models, but only for a fraction of the sequence, and should therefore only be used with caution.

  9. Frontiers of NMR in Molecular Biology

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-08-25

    NMR spectroscopy is expanding the horizons of structural biology by determining the structures and describing the dynamics of blobular proteins in aqueous solution, as well as other classes of proteins including membrane proteins and the polypeptides that form the aggregates diagnostic of prion and amyloid diseases. Significant results are also emerging on DNA and RNA oligomers and their complexes with proteins. This meeting focused attention on key structural questions emanating from molecular biology and how NMR spectroscopy can be used to answer them.

  10. Electronic [UV-Visible] and vibrational [FT-IR, FT-Raman] investigation and NMR-mass spectroscopic analysis of terephthalic acid using quantum Gaussian calculations.

    Science.gov (United States)

    Karthikeyan, N; Prince, J Joseph; Ramalingam, S; Periandy, S

    2015-03-15

    In this research work, the vibrational IR, polarization Raman, NMR and mass spectra of terephthalic acid (TA) were recorded. The observed fundamental peaks (IR, Raman) were assigned according to their distinctiveness region. The hybrid computational calculations were carried out for calculating geometrical and vibrational parameters by DFT (B3LYP and B3PW91) methods with 6-31++G(d,p) and 6-311++G(d,p) basis sets and the corresponding results were tabulated. The molecular mass spectral data related to base molecule and substitutional group of the compound was analyzed. The modification of the chemical property by the reaction mechanism of the injection of dicarboxylic group in the base molecule was investigated. The (13)C and (1)H NMR spectra were simulated by using the gauge independent atomic orbital (GIAO) method and the absolute chemical shifts related to TMS were compared with experimental spectra. The study on the electronic and optical properties; absorption wavelengths, excitation energy, dipole moment and frontier molecular orbital energies, were performed by hybrid Gaussian calculation methods. The orbital energies of different levels of HOMO and LUMO were calculated and the molecular orbital lobe overlapping showed the inter charge transformation between the base molecule and ligand group. From the frontier molecular orbitals (FMO), the possibility of electrophilic and nucleophilic hit also analyzed. The NLO activity of the title compound related to Polarizability and hyperpolarizability were also discussed. The present molecule was fragmented with respect to atomic mass and the mass variation depends on the substitutions have also been studied. Crown Copyright © 2014. Published by Elsevier B.V. All rights reserved.

  11. Electronic [UV-Visible] and vibrational [FT-IR, FT-Raman] investigation and NMR-mass spectroscopic analysis of terephthalic acid using quantum Gaussian calculations

    Science.gov (United States)

    Karthikeyan, N.; Joseph Prince, J.; Ramalingam, S.; Periandy, S.

    2015-03-01

    In this research work, the vibrational IR, polarization Raman, NMR and mass spectra of terephthalic acid (TA) were recorded. The observed fundamental peaks (IR, Raman) were assigned according to their distinctiveness region. The hybrid computational calculations were carried out for calculating geometrical and vibrational parameters by DFT (B3LYP and B3PW91) methods with 6-31++G(d,p) and 6-311++G(d,p) basis sets and the corresponding results were tabulated. The molecular mass spectral data related to base molecule and substitutional group of the compound was analyzed. The modification of the chemical property by the reaction mechanism of the injection of dicarboxylic group in the base molecule was investigated. The 13C and 1H NMR spectra were simulated by using the gauge independent atomic orbital (GIAO) method and the absolute chemical shifts related to TMS were compared with experimental spectra. The study on the electronic and optical properties; absorption wavelengths, excitation energy, dipole moment and frontier molecular orbital energies, were performed by hybrid Gaussian calculation methods. The orbital energies of different levels of HOMO and LUMO were calculated and the molecular orbital lobe overlapping showed the inter charge transformation between the base molecule and ligand group. From the frontier molecular orbitals (FMO), the possibility of electrophilic and nucleophilic hit also analyzed. The NLO activity of the title compound related to Polarizability and hyperpolarizability were also discussed. The present molecule was fragmented with respect to atomic mass and the mass variation depends on the substitutions have also been studied.

  12. Validation of quantitative {sup 1}H NMR method for the analysis of pharmaceutical formulations; Validacao de metodo quantitativo por RMN de {sup 1}H para analises de formulacoes farmaceuticas

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Maiara da S. [Universidade de Sao Paulo (USP), Sao Carlos, SP (Brazil). Instituto de Quimica; Colnago, Luiz Alberto, E-mail: luiz.colnago@embrapa.br [Embrapa Instrumentacao, Sao Carlos, SP (Brazil)

    2013-09-01

    The need for effective and reliable quality control in products from pharmaceutical industries renders the analyses of their active ingredients and constituents of great importance. This study presents the theoretical basis of Superscript-One H NMR for quantitative analyses and an example of the method validation according to Resolution RE N. 899 by the Brazilian National Health Surveillance Agency (ANVISA), in which the compound paracetamol was the active ingredient. All evaluated parameters (selectivity, linearity, accuracy, repeatability and robustness) showed satisfactory results. It was concluded that a single NMR measurement provides structural and quantitative information of active components and excipients in the sample. (author)

  13. Solid-state NMR of polymers

    International Nuclear Information System (INIS)

    Mirau, P.

    2001-01-01

    solids, for example, and the chemical shifts can be directly related to the chain conformation. Solid-state NMR is also an efficient way to monitor the reactivity of polymers, since chemical changes often result in large spectral changes. The relaxation times in solids depend not only on the chain dynamics, but also on the morphology over a length scale of 20-200 A. NMR has been extensively used to measure the length scale of mixing in blends and multiphase polymers, and the domain sizes in semicrystalline polymers. Solid-state NMR methods have been greatly expanded with the introduction of multi-dimensional NMR. These studies have led to a molecular level understanding of the dynamics traditionally observed by dielectric and dynamic-mechanical spectroscopy, and a better understanding of the relationship between polymer morphology and macroscopic properties

  14. Multivariate analysis of fingerprinting of majority secondary metabolites of propolis of Costa Rica using proton nuclear magnetic resonance (1H-NMR)

    International Nuclear Information System (INIS)

    Umana Rojas, Eduardo

    2013-01-01

    Propolis is produced by Apis mellifera bees from resins of plants that are found around the apiary. The chemical composition is highly variable and Costa Rica has reported without studies of characterization to define the types of propolis in the country. 119 samples were collected from beekeeping areas of the country. The spectrum of 1 H-NMR and its antioxidant activity against DPPH radical were measured. The spectra have been divided into 243 blocks of 0,04 ppm and processed with the Minitab software for multivariate analysis. 99 of the samples collected were used for construction of models for the valuation of the predictive ability of the model have been used coefficients of determination (R 2 ) of prediction by the software and the remaining 20 samples. The existence of three types of propolis with chemically different metabolomes were determined by principal component analysis (PCA). A prediction model was constructed by analysis of partial least squares (PLS). The prediction model has allowed to classify a propolis according to the level of anti-oxidant activity (AAO), high (type I and II) or low (type III) from the spectrum of 1 H-NMR. The R 2 has been 0.88 and R 2 prediction of 0, 718 for new samples. The n-coniferyl benzoate of group I and nemorosone of the group II as two discriminated antioxidants among the groups I and II were isolated and high concentration levels of these compounds have been differentiated with respect to type III. This has allowed the construction of a linear discriminant model with a success rate of 100% for the samples used for formulation and 92,9 for the prediction of different samples. The classification systems could be applied to the standardization of the quality of propolis from Costa Rica for future medicinal or cosmetic applications that take advantage of its antioxidant properties. Also, the methylated derivative has isolated and identified of the n-coniferyl benzoate thereof propolis than was obtained his counterpart

  15. 1H NMR spectra dataset and solid-state NMR data of cowpea (Vigna unguiculata).

    Science.gov (United States)

    Alves Filho, Elenilson G; Silva, Lorena M A; Teofilo, Elizita M; Larsen, Flemming H; de Brito, Edy S

    2017-04-01

    In this article the NMR data from chemical shifts, coupling constants, and structures of all the characterized compounds were provided, beyond a complementary PCA evaluation for the corresponding manuscript (E.G. Alves Filho, L.M.A. Silva, E.M. Teofilo, F.H. Larsen, E.S. de Brito, 2017) [3]. In addition, a complementary assessment from solid-state NMR data was provided. For further chemometric analysis, numerical matrices from the raw 1 H NMR data were made available in Microsoft Excel workbook format (.xls).

  16. Structural investigation of e-beam cured epoxy resins through solid state NMR

    International Nuclear Information System (INIS)

    Alessi, Sabina; Spinella, Alberto; Caponetti, Eugenio; Dispenza, Clelia; Spadaro, Giuseppe

    2012-01-01

    In this paper the network structure of e-beam cured DGEBF based epoxy resins is investigated. Two epoxy systems, having different reactivity and cured in different process conditions, were analyzed through solid state NMR spectroscopy. The analysis shows that the more reactive system has higher cross-linking density and higher uniformity of network distribution. Similar information were obtained, in a previous work, on the same systems through dynamic mechanical thermal analysis. It is worth noting that unlike DMTA tests, which interfere with the molecular structure of the analyzed material, due to the heating during the analysis itself, more reliable information, without any artefact, are obtained by solid state NMR, carried out at constant room temperature. - Highlights: ► The structure of two e-beam cured epoxy systems is investigated through solid state NMR. ► The aim is to have direct information about the structure without inducing modifications. ► The different molecular structures are able to emphasize the response of solid state NMR. ► T 1 H, T 1ρ H and T CH measurements indicate different cross-linking degrees. ► The NMR results are in agreement with DMTA analysis performed in a previous paper.

  17. NMR data-driven structure determination using NMR-I-TASSER in the CASD-NMR experiment

    International Nuclear Information System (INIS)

    Jang, Richard; Wang, Yan; Xue, Zhidong; Zhang, Yang

    2015-01-01

    NMR-I-TASSER, an adaption of the I-TASSER algorithm combining NMR data for protein structure determination, recently joined the second round of the CASD-NMR experiment. Unlike many molecular dynamics-based methods, NMR-I-TASSER takes a molecular replacement-like approach to the problem by first threading the target through the PDB to identify structural templates which are then used for iterative NOE assignments and fragment structure assembly refinements. The employment of multiple templates allows NMR-I-TASSER to sample different topologies while convergence to a single structure is not required. Retroactive and blind tests of the CASD-NMR targets from Rounds 1 and 2 demonstrate that even without using NOE peak lists I-TASSER can generate correct structure topology with 15 of 20 targets having a TM-score above 0.5. With the addition of NOE-based distance restraints, NMR-I-TASSER significantly improved the I-TASSER models with all models having the TM-score above 0.5. The average RMSD was reduced from 5.29 to 2.14 Å in Round 1 and 3.18 to 1.71 Å in Round 2. There is no obvious difference in the modeling results with using raw and refined peak lists, indicating robustness of the pipeline to the NOE assignment errors. Overall, despite the low-resolution modeling the current NMR-I-TASSER pipeline provides a coarse-grained structure folding approach complementary to traditional molecular dynamics simulations, which can produce fast near-native frameworks for atomic-level structural refinement

  18. NMR data-driven structure determination using NMR-I-TASSER in the CASD-NMR experiment.

    Science.gov (United States)

    Jang, Richard; Wang, Yan; Xue, Zhidong; Zhang, Yang

    2015-08-01

    NMR-I-TASSER, an adaption of the I-TASSER algorithm combining NMR data for protein structure determination, recently joined the second round of the CASD-NMR experiment. Unlike many molecular dynamics-based methods, NMR-I-TASSER takes a molecular replacement-like approach to the problem by first threading the target through the PDB to identify structural templates which are then used for iterative NOE assignments and fragment structure assembly refinements. The employment of multiple templates allows NMR-I-TASSER to sample different topologies while convergence to a single structure is not required. Retroactive and blind tests of the CASD-NMR targets from Rounds 1 and 2 demonstrate that even without using NOE peak lists I-TASSER can generate correct structure topology with 15 of 20 targets having a TM-score above 0.5. With the addition of NOE-based distance restraints, NMR-I-TASSER significantly improved the I-TASSER models with all models having the TM-score above 0.5. The average RMSD was reduced from 5.29 to 2.14 Å in Round 1 and 3.18 to 1.71 Å in Round 2. There is no obvious difference in the modeling results with using raw and refined peak lists, indicating robustness of the pipeline to the NOE assignment errors. Overall, despite the low-resolution modeling the current NMR-I-TASSER pipeline provides a coarse-grained structure folding approach complementary to traditional molecular dynamics simulations, which can produce fast near-native frameworks for atomic-level structural refinement.

  19. A new Schiff base compound N,N'-(2,2-dimetylpropane)-bis(dihydroxylacetophenone): synthesis, experimental and theoretical studies on its crystal structure, FTIR, UV-visible, 1H NMR and 13C NMR spectra.

    Science.gov (United States)

    Saheb, Vahid; Sheikhshoaie, Iran

    2011-10-15

    The Schiff base compound, N,N'-(2,2-dimetylpropane)-bis(dihydroxylacetophenone) (NDHA) is synthesized through the condensation of 2-hydroxylacetophenone and 2,2-dimethyl 1,3-amino propane in methanol at ambient temperature. The yellow crystalline precipitate is used for X-ray single-crystal determination and measuring Fourier transform infrared (FTIR), UV-visible, (1)H NMR and (13)C NMR spectra. Electronic structure calculations at the B3LYP, PBEPBE and PW91PW91 levels of theory are performed to optimize the molecular geometry and to calculate the FTIR, (1)H NMR and (13)C NMR spectra of the compound. Time-dependent density functional theory (TDDFT) method is used to calculate the UV-visible spectrum of NDHA. Vibrational frequencies are determined experimentally and compared with those obtained theoretically. Vibrational assignments and analysis of the fundamental modes of the compound are also performed. All theoretical methods can well reproduce the structure of the compound. The (1)H NMR and (13)C NMR chemical shifts calculated by all DFT methods are consistent with the experimental data. However, the NMR shielding tensors computed at the B3LYP/6-31+G(d,p) level of theory are in better agreement with experimental (1)H NMR and (13)C NMR spectra. The electronic absorption spectrum calculated at the B3LYP/6-31+G(d,p) level by using TD-DFT method is in accordance with the observed UV-visible spectrum of NDHA. In addition, some quantum descriptors of the molecule are calculated and conformational analysis is performed and the results were compared with the crystallographic data. Copyright © 2011 Elsevier B.V. All rights reserved.

  20. Teaching NMR Using Online Textbooks

    Directory of Open Access Journals (Sweden)

    Joseph P. Hornak

    1999-12-01

    Full Text Available Nuclear magnetic resonance (NMR spectroscopy has almost become an essential analytical tool for the chemist. High-resolution one- and multi-dimensional NMR, timedomain NMR, and NMR microscopy are but a few of the NMR techniques at a chemist's disposal to determine chemical structure and dynamics. Consequently, even small chemistry departments are finding it necessary to provide students with NMR training and experience in at least some of these techniques. The hands-on experience is readily provided with access to state-of-the-art commercial spectrometers. Instruction in the principles of NMR is more difficult to achieve as most instructors try to teach NMR using single organic or analytical chemistry book chapters with static figures. This paper describes an online textbook on NMR spectroscopy called The Basics of NMR (http://www.cis.rit.edu/htbooks/nmr/ suitable for use in teaching the principles of NMR spectroscopy. The book utilizes hypertext and animations to present the principles of NMR spectroscopy. The book can be used as a textbook associated with a lecture or as a stand-alone teaching tool. Conference participants are encouraged to review the textbook and evaluate its suitability for us in teaching NMR spectroscopy to undergraduate chemistry majors.

  1. O-17 NMR measurement of water

    International Nuclear Information System (INIS)

    Fukazawa, Nobuyuki

    1990-01-01

    Recently, attention has been paid to the various treatment of water and the utilization of water by magnetic treatment, electric field treatment and so on. It has been said that by these treatments, the change in the properties of water arises. The state of this treated water cannot be explained by the properties of water from conventional physical and chemical standpoints. In addition, the method of measurement of whether the change arose or not is not yet determined. It is necessary to establish the method of measurement for the basic state of water. In this study, O-17 NMR which observes the state of water directly at molecular or atomic level was investigated as the method of measuring water. The measurement of O-17 NMR was carried out with a JNR 90Q FT NMR of Fourier transformation type of JEOL Ltd. The experimental method and the results are reported. The result of measurement of the O-17 NMR spectrum for distilled ion exchange water is shown. It is know that it has very wide line width as compared with the NMR spectra of protons and C-13. The relative sensitivity of O-17 observation is about 1/100,000 of that of protons. As to the information on the state of water obtained by O-17 NMR, there are chemical shift and line width. As temperature rose, the line width showed decrease, which seemed to be related to the decrease of hydrogen combination. (K.I.)

  2. Effects of cooking on the cell walls (dietary fiber) of 'Scarlet Warren' winter squash ( Cucurbita maxima ) studied by polysaccharide linkage analysis and solid-state (13)C NMR.

    Science.gov (United States)

    Ratnayake, R M Sunil; Sims, Ian M; Newman, Roger H; Melton, Laurence D

    2011-07-13

    Cell wall polysaccharides of 'Scarlet Warren' winter squash ( Cucurbita maxima ) were investigated before and after thermal processing. Linkage analysis of polysaccharides was done by gas chromatography coupled to mass spectrometry (GC-MS). The linkage analysis showed the cell wall polysaccharide compositions of raw and cooked squash were similar. The total pectic polysaccharides (galacturonan, rhamnogalacturonan, arabinan, and arabinogalactan) contents of the cell walls of both raw and cooked squash were 39 mol %. The amounts of pectic polysaccharides and xyloglucan in the cell walls of squash showed little alteration on heating. The cellulose content of the raw and cooked cell walls was relatively high at 47 mol %, whereas the xyloglucan content was low at 4 mol %. Solid-state (13)C nuclear magnetic resonance (NMR) spectroscopy techniques were used to examine the molecular motion of the polysaccharides in the cell walls. The mobility of highly flexible galactan depends on the water content of the sample, but no difference was seen between raw and cooked samples. Likewise, the mobility of semimobile pectic polysaccharides was apparently unaltered by cooking. No change was detected in the rigid cellulose microfibrils on cooking.

  3. 1H NMR spectroscopy-based metabolomics analysis for the diagnosis of symptomatic E. coli-associated urinary tract infection (UTI).

    Science.gov (United States)

    Lussu, Milena; Camboni, Tania; Piras, Cristina; Serra, Corrado; Del Carratore, Francesco; Griffin, Julian; Atzori, Luigi; Manzin, Aldo

    2017-09-21

    Urinary tract infection (UTI) is one of the most common diagnoses in girls and women, and to a lesser extent in boys and men younger than 50 years. Escherichia coli, followed by Klebsiella spp. and Proteus spp., cause 75-90% of all infections. Infection of the urinary tract is identified by growth of a significant number of a single species in the urine, in the presence of symptoms. Urinary culture is an accurate diagnostic method but takes several hours or days to be carried out. Metabolomics analysis aims to identify biomarkers that are capable of speeding up diagnosis. Urine samples from 51 patients with a prior diagnosis of Escherichia coli-associated UTI, from 21 patients with UTI caused by other pathogens (bacteria and fungi), and from 61 healthy controls were analyzed. The 1 H-NMR spectra were acquired and processed. Multivariate statistical models were applied and their performance was validated using permutation test and ROC curve. Orthogonal Partial Least Squares-discriminant Analysis (OPLS-DA) showed good separation (R 2 Y = 0.76, Q2=0.45, p infections to test their specificity. Acetate and trimethylamine were identified as optimal candidates for biomarkers for UTI diagnosis. The conclusions support the possibility of a fast diagnostic test for Escherichia coli-associated UTI using acetate and trimethylamine concentrations.

  4. Synthesis, structural, spectral (FTIR, FT-Raman, UV, NMR), NBO and first order hyperpolarizability analysis of N-phenylbenzenesulfonamide by density functional theory.

    Science.gov (United States)

    Govindarasu, K; Kavitha, E; Sundaraganesan, N

    2014-12-10

    In this study sulfonamide compound, N-phenylbenzenesulfonamide (NPBS) has been synthesized and grown as a high quality single crystal by the slow evaporation solution growth technique. The grown crystals were characterized by the Fourier transform infrared (4000-400cm(-1)), Fourier transform Raman (3500-500cm(-1)), UV-Vis (200-800nm) and NMR spectroscopy. Density functional (DFT) calculations have been carried out for the compound NPBS by utilizing DFT level of theory using B3LYP/6-31G(d,p) as basis set. The theoretical vibrational frequencies and optimized geometric parameters such as bond lengths and bond angles have been calculated by using quantum chemical methods. The stability of the molecule arising from hyper conjugative interaction and charge delocalization has been analyzed using NBO analysis. The dipole moment, linear polarizability and first order hyperpolarizability values were also computed. The chemical reactivity and ionization potential of NPBS were also calculated. In addition, Molecular Electrostatic Potential (MEP), Frontier Molecular Orbital (FMO) analysis was investigated using theoretical calculations. The thermodynamic properties of the compound were calculated at different temperatures and corresponding relations between the properties and temperature were also studied. Finally, geometric parameters, vibrational bands were compared with available experimental data of the molecules. Published by Elsevier B.V.

  5. Nuclear magnetic resonance (NMR): principles and applications

    International Nuclear Information System (INIS)

    Quibilan, E.I.

    The basis for the phenomenon of nuclear magnetic resonance (NMR) is the ability of certain nuclei possessing both intrinsic angular momentum or ''spin'' I and magnetic moment to absorb electromagnetic energy in the radio frequency range. In principle, there are approximately 200 nuclei which may be investigated using the NMR technique. The NMR spectrum consists of intensity peaks along an axis calibrated in terms of the steady magnetic field or the frequency of the radiofrequency electromagnetic radiation. Analysis of the number, spacing, position and intensity of the lines in an NMR spectrum consists of intensity peaks along an axis calibrated in terms of the steady magnetic field or the frequency of the radiofrequency electromagnetic radiation. Analysis of the number, spacing, position and intensity of the lines in an NMR spectrum provides a variety of qualitative and quantitative analytical applications. The most obvious applications consist of the measurements of nuclear properties, such as spin number and nuclear magnetic moment. In liquids, the fine structure of resonance spectra provides a tool for chemical identification and molecular structure analysis. Other applications include the measurements of self-diffusion coefficients, magnetic fields and field homogeneity, inter-nuclear distances, and, in some cases, the water content of biological materials. (author)

  6. Direct Comparison of 19F qNMR and 1H qNMR by Characterizing Atorvastatin Calcium Content

    Directory of Open Access Journals (Sweden)

    Yang Liu

    2016-01-01

    Full Text Available Quantitative nuclear magnetic resonance (qNMR is a powerful tool in measuring drug content because of its high speed, sensitivity, and precision. Most of the reports were based on proton qNMR (1H qNMR and only a few fluorine qNMR (19F qNMR were reported. No research has been conducted to directly compare the advantage and disadvantage between these two methods. In the present study, both 19F and 1H qNMR were performed to characterize the content of atorvastatin calcium with the same internal standard. Linearity, precision, and results from two methods were compared. Results showed that 19F qNMR has similar precision and sensitivity to 1H qNMR. Both methods generate similar results compared to mass balance method. Major advantage from 19F qNMR is that the analyte signal is with less or no interference from impurities. 19F qNMR is an excellent approach to quantify fluorine-containing analytes.

  7. Direct Comparison of 19F qNMR and 1H qNMR by Characterizing Atorvastatin Calcium Content

    Science.gov (United States)

    Liu, Yang; Liu, Zhaoxia; Yang, Huaxin

    2016-01-01

    Quantitative nuclear magnetic resonance (qNMR) is a powerful tool in measuring drug content because of its high speed, sensitivity, and precision. Most of the reports were based on proton qNMR (1H qNMR) and only a few fluorine qNMR (19F qNMR) were reported. No research has been conducted to directly compare the advantage and disadvantage between these two methods. In the present study, both 19F and 1H qNMR were performed to characterize the content of atorvastatin calcium with the same internal standard. Linearity, precision, and results from two methods were compared. Results showed that 19F qNMR has similar precision and sensitivity to 1H qNMR. Both methods generate similar results compared to mass balance method. Major advantage from 19F qNMR is that the analyte signal is with less or no interference from impurities. 19F qNMR is an excellent approach to quantify fluorine-containing analytes. PMID:27688925

  8. Direct Comparison of (19)F qNMR and (1)H qNMR by Characterizing Atorvastatin Calcium Content.

    Science.gov (United States)

    Liu, Yang; Liu, Zhaoxia; Yang, Huaxin; He, Lan

    2016-01-01

    Quantitative nuclear magnetic resonance (qNMR) is a powerful tool in measuring drug content because of its high speed, sensitivity, and precision. Most of the reports were based on proton qNMR ((1)H qNMR) and only a few fluorine qNMR ((19)F qNMR) were reported. No research has been conducted to directly compare the advantage and disadvantage between these two methods. In the present study, both (19)F and (1)H qNMR were performed to characterize the content of atorvastatin calcium with the same internal standard. Linearity, precision, and results from two methods were compared. Results showed that (19)F qNMR has similar precision and sensitivity to (1)H qNMR. Both methods generate similar results compared to mass balance method. Major advantage from (19)F qNMR is that the analyte signal is with less or no interference from impurities. (19)F qNMR is an excellent approach to quantify fluorine-containing analytes.

  9. Microprocessorized NMR measurement

    International Nuclear Information System (INIS)

    Rijllart, A.

    1984-01-01

    An MC68000 CAMAC microprocessor system for fast and accurate NMR signal measurement will be presented. A stand-alone CAMAC microprocessor system (MC68000 STAC) with a special purpose interface sweeps a digital frequency synthesizer and digitizes the NMR signal with a 16-bit ADC of 17 μs conversion time. It averages the NMR signal data over many sweeps and then transfers it through CAMAC to a computer for calculation of the signal parameters. The computer has full software control over the timing and sweep settings of this signal averager, and thus allows optimization of noise suppression. Several of these processor systems can be installed in the same crate for parallel processing, and the flexibility of the STAC also allows easy adaptation to other applications such as transient recording or phase-sensitive detection. (orig.)

  10. 1H NMR analysis of long-chain-branched strong polyelectrolytes obtained by vinyl/divinyl monomer copolymerization in aqueous medium

    Czech Academy of Sciences Publication Activity Database

    Podešva, Jiří; Spěváček, Jiří; Kratochvíl, Pavel; Netopilík, Miloš

    2013-01-01

    Roč. 18, č. 7 (2013), s. 557-565 ISSN 1023-666X Institutional support: RVO:61389013 Keywords : long-chain branching * NMR * polyelectrolytes Subject RIV: CD - Macromolecular Chemistry Impact factor: 1.487, year: 2013

  11. Vibrational spectra, molecular structure, NBO, NMR, UV, first order hyperpolarizability, analysis of (S)-(-)-N-(5-Nitro-2-pyridyl) alaninol by Density functional theory.

    Science.gov (United States)

    Govindarasu, K; Kavitha, E

    2014-06-05

    In this study, geometrical optimization, spectroscopic analysis, electronic structure and nuclear magnetic resonance studies of (S)-(-)-N-(5-Nitro-2-pyridyl) alaninol (abbreviated as SN5N2PLA) were investigated by utilizing HF and DFT/B3LYP with 6-31G(d,p) as basis set. The Fourier transform infrared (FT-IR) and FT-Raman spectra of SN5N2PLA were recorded in the region 4000-400cm(-1) and 3500-50cm(-1), respectively. Complete vibrational assignments, analysis and correlation of the fundamental modes for the title compound were carried out. UV-Visible spectrum of the compound that dissolved in methanol were recorded in the region 200-800nm and the electronic properties HOMO and LUMO energies were measured by TD-DFT approach. The calculated HOMO and LUMO energies show that charge transfer occurs within the molecule. The molecular stability and bond strength have been investigated by applying the Natural Bond Orbital (NBO) analysis. The (1)H and (13)C nuclear magnetic resonance (NMR) chemical shifts of SN5N2PLA were calculated using the GIAO method in methanol solution and compared with the measured experimental data. The dipole moment, polarizability and first order hyperpolarizability values were also computed. The polarizability and first hyperpolarizability of the studied molecule indicate that the compound is a good candidate of nonlinear optical materials. The Chemical reactivity and Thermodynamic properties of SN5N2PLA at different temperature are calculated. In addition, molecular electrostatic potential (MEP), frontier molecular orbitals (FMOs) analysis were investigated using theoretical calculations. Published by Elsevier B.V.

  12. Vibrational analysis using FT-IR, FT-Raman spectra and HF-DFT methods and NBO, NLO, NMR, HOMO-LUMO, UV and electronic transitions studies on 2,2,4-trimethyl pentane.

    Science.gov (United States)

    Suvitha, A; Periandy, S; Govindarajan, M; Gayathri, P

    2015-03-05

    In this work, the vibrational spectral analysis was carried out by using Raman and infrared spectroscopy in the range 100-4000cm(-1)and 50-4000cm(-1), respectively, for 2,2,4-Trimethyl Pentane, TMP (C8H18) molecule. The molecular structure, fundamental vibrational frequencies and intensity of the vibrational bands are interpreted with the aid of structure optimizations and geometrical parameter calculations based on Hartree Fock (HF) and density functional theory (DFT) method with 6-311++G(d,p) basis set. The scaled B3LYP/6-311++G(d,p) results shows the best agreement with the experimental values over the other method. The calculated HOMO and LUMO energies shows that charge transfer within the molecule. The physical reactions of single bond hydrocarbon TMP were investigated. The results of the calculations were applied to simulate spectra of the title compound, which shows the excellent agreement with observed spectra. Besides, Mulliken atomic charges, UV, frontier molecular orbital (FMO), MEP, NLO activity, Natural Bond-Orbital (NBO) analysis, NMR and thermodynamic properties of title molecule were also performed. Copyright © 2014 Elsevier B.V. All rights reserved.

  13. Portable microcoil NMR detection coupled to capillary electrophoresis.

    Science.gov (United States)

    Diekmann, Joana; Adams, Kristl L; Klunder, Gregory L; Evans, Lee; Steele, Paul; Vogt, Carla; Herberg, Julie L

    2011-02-15

    High-efficiency separation techniques, such as capillary electrophoresis (CE), coupled to a nondestructive nuclear magnetic resonance (NMR) spectrometer offer the ability to separate, chemically identify, and provide structural information on analytes in small sample volumes. Previous CE-NMR coupled systems utilized laboratory-scale NMR magnets and spectrometers, which require very long separation capillaries. New technological developments in electronics have reduced the size of the NMR system, and small 1-2 T permanent magnets provide the possibilities of a truly portable NMR. The microcoils used in portable and laboratory-scale NMR may offer the advantage of improved mass sensitivity because the limit of detection (LOD) is proportional to the coil diameter. In this work, CE is coupled with a portable, briefcase-sized NMR system that incorporates a microcoil probe and a 1.8 T permanent magnet to measure (19)F NMR spectra. Separations of fluorinated molecules are demonstrated with stopped- and continuous-flow NMR detection. The results demonstrate that coupling CE to a portable NMR instrument is feasible and can provide a low-cost method to obtain structural information on microliter samples. An LOD of 31.8 nmol for perfluorotributylamine with a resolution of 4 ppm has been achieved with this system.

  14. Life cycle analysis of electricity systems: Methods and results

    International Nuclear Information System (INIS)

    Friedrich, R.; Marheineke, T.

    1996-01-01

    The two methods for full energy chain analysis, process analysis and input/output analysis, are discussed. A combination of these two methods provides the most accurate results. Such a hybrid analysis of the full energy chains of six different power plants is presented and discussed. The results of such analyses depend on time, site and technique of each process step and, therefore have no general validity. For renewable energy systems the emissions form the generation of a back-up system should be added. (author). 7 figs, 1 fig

  15. Molecular structure, vibrational, UV, NMR, HOMO-LUMO, MEP, NLO, NBO analysis of 3,5 di tert butyl 4 hydroxy benzoic acid

    Science.gov (United States)

    Mathammal, R.; Sangeetha, K.; Sangeetha, M.; Mekala, R.; Gadheeja, S.

    2016-09-01

    In this study, we report a combined experimental and theoretical study on molecular structure and vibrational spectra of 3,5 di tert butyl 4 hydroxy benzoic acid. The properties of title compound have been evaluated by quantum chemical calculation (DFT) using B3LYP functional and 6-31 + G (d, p) as basis set. IR Spectra has been recorded using Fourier transform infrared spectroscopy (FT-IR) in the region 4000-400 cm-1. The vibrational assignment of the calculated normal modes has been made on the basis set. The isotropic chemical shifts computed by 13C and 1H NMR (Nuclear Magnetic Resonance) analyses also show good agreement with experimental observations. The theoretical UV-Vis spectrum of the compound are used to study the visible absorption maxima (λ max). The structure activity relationship have been interpreted by mapping electrostatic potential surface (MEP), which is valuable information for the quality control of medicines and drug receptor interactions. The Mullikan charges, HOMO (Highest Occupied Molecular Orbital) - LUMO (Lowest Unoccupied Molecular Orbital) energy are analyzed. HOMO-LUMO energy gap and other related molecular properties are also calculated. The Natural Bond Orbital (NBO) analysis is carried out to investigate the various intra and inter molecular interactions of molecular system. The Non-linear optical properties such as dipole moment (μ), polarizability (αtot) and molecular first order hyperpolarizability (β) of the title compound are computed with B3LYP/6-31 + G (d,p) level of theory.

  16. Investigation of the preventive effect of Sijunzi decoction on mitomycin C-induced immunotoxicity in rats by 1H NMR and MS-based untargeted metabolomic analysis.

    Science.gov (United States)

    Guan, Zhibo; Wu, Juan; Wang, Cancan; Zhang, Fang; Wang, Yinan; Wang, Miao; Zhao, Min; Zhao, Chunjie

    2018-01-10

    Sijunzi decoction (SJZD) is a well known traditional Chinese prescription used for the treatment of gastrointestinal disorders and immunity enhancement. It has been found to indeed improve life quality of chemotherapy patients and extensive used in clinical conbined with chemotherapeutics for the treatment of cancer. The aim of this study was to investigate the preventive effect of the immunotoxicity of SJZD on mitomycin C (MMC) and the metabolic mechanism of action. NMR and MS-based metabolomics approaches were combined for monitoring MMC-induced immunotoxicity and the protective effect of SJZD. Body weight change and mortality, histopathological observations and relative viscera weight determinations of spleen and thymus, sternum micronucleus assay and hematological analysis were used to confirm the immunotoxicity and attenuation effects. An OPLS-DA approach was used to screen potential biomarkers of immunotoxicity and the MetaboAnalyst and KEGG PATHWAY Database were used to investigate the metabolic pathways. 8 biomarkers in plasma samples, 19 in urine samples and 10 in spleen samples were identified as being primarily involved in amino acid metabolism, carbohydrate metabolism and lipid metabolism. The most critical pathway was alanine, aspartate and glutamate metabolism. The variations in biomarkers revealed the preventive effect of the immunotoxicity of SJZD on MMC and significant for speculating the possible metabolic mechanism. Copyright © 2017 Elsevier Ireland Ltd. All rights reserved.

  17. Muscular pathology: echographic and NMR imaging aspects

    International Nuclear Information System (INIS)

    Pascal-Suisse, P.; Beaurain, P.; Mougniot, C.

    1995-01-01

    A comparison of echographic techniques and NMR imaging has been done for the diagnosis of muscular trauma and tumor pathologies. In traumatic pathology, the echographic analysis allows to determine the complete assessment of recent muscular injuries. NMR imaging can be used in granuloma or fibrous callosity appreciation and for the analysis of deep injury (muscles and muscles-tendon junctions) and of muscular aponeurosis. Echography must be used together with color coding Doppler technique in the diagnosis of tumor pathology and for the study of slow fluxes. The recently available energy Doppler technique seems to be powerful in the study of vascularization of small expansive formations, but their extension to adjacent bone or tissue can only be appreciated using NMR imaging. (J.S.)

  18. International symposium on NMR spectroscopy

    International Nuclear Information System (INIS)

    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.)

  19. 13C and 29Si NMR as a probe to investigate polysiloxanes used in dental applications

    International Nuclear Information System (INIS)

    Silva, Naira Machado da; Tavares, Maria Ines B.

    2001-01-01

    The properties of dental mould polymeric materials are strongly influenced by the chemical structure of both the polymer and the catalyst used in the crosslink reaction between them. In order to characterize and suggest some modifications on the materials interfacial interactions, mixtures of Polymer-catalyst were prepared. The polymer and the catalyst chemical structures were obtained by 13 C, 1 H and 129 Si NMR analysis in solution state. From the solution NMR results it was obtained the structure of the polymer and the catalyst and also the kind of the crosslink reaction taken. The CPMAS 1 '3C NMR analysis in the solid state were used to identify chemical structure of the polymeric dental moulded sample. (author)

  20. NMR of unfolded proteins

    Indian Academy of Sciences (India)

    Unknown

    2005-01-03

    Jan 3, 2005 ... out' response to environmental changes with structural complexity ... of 3D structure at atomic resolution of folded proteins ...... 5.14 HIV-1 protease. NMR identification of local structural preferences in. HIV-1 protease in the 'unfolded state' at 6 M gua- nidine hydrochloride has been reported.49 Analyses.

  1. Single-sided NMR

    CERN Document Server

    Casanova, Federico; Blümich, Bernhard

    2011-01-01

    Single-Sided NMR describes the design of the first functioning single-sided tomograph, the related measurement methods, and a number of applications. One of the key advantages to this method is the speed at which the images are obtained.

  2. NMR-based metabonomic analysis of MnO-embedded iron oxide nanoparticles as potential dual-modal contrast agents

    Science.gov (United States)

    Li, Jinquan; Zhou, Zijian; Feng, Jianghua; Cai, Shuhui; Gao, Jinhao; Chen, Zhong

    2014-05-01

    MnO-embedded iron oxide nanoparticles (MnIO-NPs) can be treated as potential dual-modal contrast agents. However, their overall bio-effects and potential toxicity remain unknown. In this study, the metabolic effects of MnIO-NPs (dosed at 1 and 5 mg Fe/kg) on Sprague-Dawley rats were investigated using metabonomic analysis, histopathological examination, and conventional biochemical analysis. The histological changes included a focal inflammation in the liver at high-dose and a slightly enlarged area of splenic white pulp after 48 h post-dose. Blood biochemical analysis showed that albumin, globulins, aspartate aminotransferase, lactate dehydrogenase, blood urea nitrogen, and glucose changed distinctly compared to the control. The metabonomic analysis of body fluids (serum and urine) and tissues (liver, kidney, and spleen) indicated that MnIO-NPs induced metabolic perturbation in rats including energy, nucleotides, amino acids and phospholipid metabolisms. Besides, the variations of supportive nutrients: valine, leucine, isoleucine, nicotinamide adenine dinucleotide (phosphate), and nicotinamide, and the conjugation substrates: glycine, taurine, glutamine, glutathione, and methyl donors (formate, sarcosine, dimethylglycine, choline, and betaine) were involved in detoxification reaction of MnIO-NPs. The obtained information would provide identifiable ground for the candidate selection and optimization.

  3. Chiral Analysis by Tandem Mass Spectrometry Using the Kinetic Method, by Polarimetry, and by [Superscript 1]H NMR Spectroscopy

    Science.gov (United States)

    Fedick, Patrick W.; Bain, Ryan M.; Bain, Kinsey; Cooks, R. Graham

    2017-01-01

    The goal of this laboratory exercise was for students to understand the concept of chirality and how enantiomeric excess (ee) is experimentally determined using the analysis of ibuprofen as an example. Students determined the enantiomeric excess of the analyte by three different instrumental methods: mass spectrometry, nuclear magnetic resonance…

  4. Xenon NMR with spectroscopic, spatial, and temporal resolution

    OpenAIRE

    Münnemann, Kerstin

    2006-01-01

    129Xe NMR has found many applications in material sciences and medicine because of two useful properties of Xenon atoms for NMR: the sensitivity to their environment due to their highly polarizable electron cloud, which results in a wide range of chemical shifts, and the ability of being hyperpolarized, which overcomes the problem of the low signal-to-noise ratio of thermally polarized Xenon. In this work a variety of different experiments were performed that combine NMR measurements with spe...

  5. Facilitated Visual Interpretation of Scores in Principal Component Analysis by Bioactivity-Labeling of 1H-NMR Spectra—Metabolomics Investigation and Identification of a New α-Glucosidase Inhibitor in Radix Astragali

    Directory of Open Access Journals (Sweden)

    Yueqiu Liu

    2017-03-01

    Full Text Available Radix Astragali is a component of several traditional medicines used for the treatment of type 2 diabetes in China. Radix Astragali is known to contain isoflavones, which inhibit α-glucosidase in the small intestines, and thus lowers the blood glucose levels. In this study, 21 samples obtained from different regions of China were extracted with ethyl acetate, then the IC50-values were determined, and the crude extracts were analyzed by 1H-NMR spectroscopy. A principal component analysis of the 1H-NMR spectra labeled with their IC50-values, that is, bioactivity-labeled 1H-NMR spectra, showed a clear correlation between spectral profiles and the α-glucosidase inhibitory activity. The loading plot and LC-HRMS/NMR of microfractions indicated that previously unknown long chain ferulates could be partly responsible for the observed antidiabetic activity of Radix Astragali. Subsequent preparative scale isolation revealed a compound not previously reported, linoleyl ferulate (1, showing α-glucosidase inhibitory activity (IC50 0.5 mM at a level comparable to the previously studied isoflavones. A closely related analogue, hexadecyl ferulate (2, did not show significant inhibitory activity, and the double bonds in the alcohol part of 1 seem to be important structural features for the α-glucosidase inhibitory activity. This proof of concept study demonstrates that bioactivity-labeling of the 1H-NMR spectral data of crude extracts allows global and nonselective identification of individual constituents contributing to the crude extract’s bioactivity.

  6. NMR for chemists and biologists

    CERN Document Server

    Carbajo, Rodrigo J

    2013-01-01

    This book offers a concise introduction to the field of nuclear magnetic resonance or NMR. It presents the basic foundations of NMR in a non-mathematical way and provides an overview of both recent and important biological applications of NMR.

  7. Calculation of the NMR chemical shift for a 4d1 system in a strong crystal field environment of trigonal symmetry with a threefold axis of quantization

    International Nuclear Information System (INIS)

    Ahn, Sang Woon; Oh, Se Woung; Ro, Seung Woo

    1986-01-01

    The NMR chemical shift arising from 4d electron angular momentum and 4d electron angular momentum and 4d electron spin dipolar-nuclear spin angular momentum interactions for a 4d 1 system in a strong crystal field environment of trigonal symmetry, where the threefold axis is chosen to be the axis of quantization axis, has been examined. A general expression using the nonmultipole expansion method (exact method) is derived for the NMR chemical shift. From this expression all the multipolar terms are determined. we observe that along the (100), (010), (110), and (111) axes the NMR chemical shifts are positive while along the (001) axis, it is negative. We observe that the dipolar term (1/R 3 ) is the dominant contribution to the NMR chemical shift except for along the (111) axis. A comparison of the multipolar terms with the exact values shows also that the multipolar results are exactly in agreement with the exact values around R≥0.2 nm. The temperature dependence analysis on the NMR chemical shifts may imply that along the (111) axis the contribution to the NMR chemical shift is dominantly pseudo contact interaction. Separation of the contributions of the Fermi and the pseudo contact interactions would correctly imply that the dipolar interaction is the dominant contribution to the NMR chemical shifts along the (100), (010), (001), and (110) axes, but along the (111) axis the Fermi contact interaction is incorrectly the dominant contribution to the NMR chemical shift. (Author)

  8. Comparative analysis of the orientation of transmembrane peptides using solid-state (2)H- and (15)N-NMR: mobility matters.

    Science.gov (United States)

    Grage, Stephan L; Strandberg, Erik; Wadhwani, Parvesh; Esteban-Martín, Santiago; Salgado, Jesús; Ulrich, Anne S

    2012-05-01

    Many solid-state nuclear magnetic resonance (NMR) approaches for membrane proteins rely on orientation-dependent parameters, from which the alignment of peptide segments in the lipid bilayer can be calculated. Molecules embedded in liquid-crystalline membranes, such as monomeric helices, are highly mobile, leading to partial averaging of the measured NMR parameters. These dynamic effects need to be taken into account to avoid misinterpretation of NMR data. Here, we compare two common NMR approaches: (2)H-NMR quadrupolar waves, and separated local field (15)N-(1)H polarization inversion spin exchange at magic angle (PISEMA) spectra, in order to identify their strengths and drawbacks for correctly determining the orientation and mobility of α-helical transmembrane peptides. We first analyzed the model peptide WLP23 in oriented dimyristoylphosphatidylcholine (DMPC) membranes and then contrasted it with published data on GWALP23 in dilauroylphosphatidylcholine (DLPC). We only obtained consistent tilt angles from the two methods when taking dynamics into account. Interestingly, the two related peptides differ fundamentally in their mobility. Although both helices adopt the same tilt in their respective bilayers (~20°), WLP23 undergoes extensive fluctuations in its azimuthal rotation angle, whereas GWALP23 is much less dynamic. Both alternative NMR methods are suitable for characterizing orientation and dynamics, yet they can be optimally used to address different aspects. PISEMA spectra immediately reveal the presence of large-amplitude rotational fluctuations, which are not directly seen by (2)H-NMR. On the other hand, PISEMA was unable to define the azimuthal rotation angle in the case of the highly dynamic WLP23, though the helix tilt could still be determined, irrespective of any dynamics parameters.

  9. ANALYSIS RESULTS FOR BUILDING 241 702-AZ A TRAIN

    International Nuclear Information System (INIS)

    DUNCAN JB; FRYE JM; COOKE CA; LI SW; BROCKMAN FJ

    2006-01-01

    This report presents the analyses results for three samples obtained under RPP-PLAN-28509, Sampling and Analysis Plan for Building 241 702-AZ A Train. The sampling and analysis was done in response to problem evaluation request number PER-2004-6139, 702-AZ Filter Rooms Need Radiological Cleanup Efforts

  10. ANALYSIS RESULTS FOR BUILDING 241 702-AZ A TRAIN

    Energy Technology Data Exchange (ETDEWEB)

    DUNCAN JB; FRYE JM; COOKE CA; LI SW; BROCKMAN FJ

    2006-12-13

    This report presents the analyses results for three samples obtained under RPP-PLAN-28509, Sampling and Analysis Plan for Building 241 702-AZ A Train. The sampling and analysis was done in response to problem evaluation request number PER-2004-6139, 702-AZ Filter Rooms Need Radiological Cleanup Efforts.

  11. Characterization of coke by MAS 13C-NMR

    International Nuclear Information System (INIS)

    Nagy, J.B.; Tuel, A.; Munck, M.; Derouane, E.G.

    1991-01-01

    The molecular architecture of coke is difficult to determine. Nuclear magnetic resonance spectroscopy allows one to understand the chemical environment or types of hydrogen and carbon in the sample. It is also possible to estimate the proportion of atoms in the various environments. Here, liquid-state and solid-state NMR have been used to characterize different series of feedstocks and coke samples. Liquid phase 13 C NMR was used to analyse feeds and products separated by HPLC (PEW) in fractions called aliphatics, mono-, di-, tri-, and polyaromatics. An internal lock with deuterated chloroform was used due to the small amount of material present in each fraction. The NMR analysis gives the aromaticity and gives a nice correlation with the results obtained by GC/MS (average no of C-atoms in each fraction, chainlength, no. of substituents etc.). Structural features were gained by comparison of different fractions, while differences were seen, when feed and product were compared. For liquid samples, a model has been proposed in which the feed is supposed to be described as a mixture of six model compounds. Results concerning three series of feedstocks and the structural paramaters deduced from 13 C and 1 H NMR spectra are discussed and compared with the experimental data obtained from elemental analysis. In the solid state, by using Cross Polarization (CP) and Magic Angle Spinning (MAS), it is possible to obtain information on different carbon structural types. Structural parameters, such as the aromaticity f a or the H/C ratio can be evaluated with a good reliability. (AB) (23 refs.)

  12. Purification and Characterization of Recombinant N-Terminally Pyroglutamate-Modified Amyloid-β Variants and Structural Analysis by Solution NMR Spectroscopy.

    Directory of Open Access Journals (Sweden)

    Christina Dammers

    Full Text Available Alzheimer's disease (AD is the leading cause of dementia in the elderly and is characterized by memory loss and cognitive decline. Pathological hallmark of AD brains are intracellular neurofibrillary tangles and extracellular amyloid plaques. The major component of these plaques is the highly heterogeneous amyloid-β (Aβ peptide, varying in length and modification. In recent years pyroglutamate-modified amyloid-β (pEAβ peptides have increasingly moved into the focus since they have been described to be the predominant species of all N-terminally truncated Aβ. Compared to unmodified Aβ, pEAβ is known to show increased hydrophobicity, higher toxicity, faster aggregation and β-sheet stabilization and is more resistant to degradation. Nuclear magnetic resonance (NMR spectroscopy is a particularly powerful method to investigate the conformations of pEAβ isoforms in solution and to study peptide/ligand interactions for drug development. However, biophysical characterization of pEAβ and comparison to its non-modified variant has so far been seriously hampered by the lack of highly pure recombinant and isotope-enriched protein. Here we present, to our knowledge, for the first time a reproducible protocol for the production of pEAβ from a recombinant precursor expressed in E. coli in natural isotope abundance as well as in uniformly [U-15N]- or [U-13C, 15N]-labeled form, with yields of up to 15 mg/l E. coli culture broth. The chemical state of the purified protein was evaluated by RP-HPLC and formation of pyroglutamate was verified by mass spectroscopy. The recombinant pyroglutamate-modified Aβ peptides showed characteristic sigmoidal aggregation kinetics as monitored by thioflavin-T assays. The quality and quantity of produced pEAβ40 and pEAβ42 allowed us to perform heteronuclear multidimensional NMR spectroscopy in solution and to sequence-specifically assign the backbone resonances under near-physiological conditions. Our results suggest

  13. LipSpin: A New Bioinformatics Tool for Quantitative 1H NMR Lipid Profiling.

    Science.gov (United States)

    Barrilero, Rubén; Gil, Miriam; Amigó, Núria; Dias, Cintia B; Wood, Lisa G; Garg, Manohar L; Ribalta, Josep; Heras, Mercedes; Vinaixa, Maria; Correig, Xavier

    2018-02-06

    The structural similarity among lipid species and the low sensitivity and spectral resolution of nuclear magnetic resonance (NMR) have traditionally hampered the routine use of 1 H NMR lipid profiling of complex biological samples in metabolomics, which remains mostly manual and lacks freely available bioinformatics tools. However, 1 H NMR lipid profiling provides fast quantitative screening of major lipid classes (fatty acids, glycerolipids, phospholipids, and sterols) and some individual species and has been used in several clinical and nutritional studies, leading to improved risk prediction models. In this Article, we present LipSpin, a free and open-source bioinformatics tool for quantitative 1 H NMR lipid profiling. LipSpin implements a constrained line shape fitting algorithm based on voigt profiles and spectral templates from spectra of lipid standards, which automates the analysis of severely overlapped spectral regions and lipid signals with complex coupling patterns. LipSpin provides the most detailed quantification of fatty acid families and choline phospholipids in serum lipid samples by 1 H NMR to date. Moreover, analytical and clinical results using LipSpin quantifications conform with other techniques commonly used for lipid analysis.

  14. The results of NMR imaging of the brain using superconductive magnets as compared to those obtained by cranial computed tomography. Ergebnisse kernspintomographischer Untersuchungen des Gehirns mit supraleitendem Magneten im Vergleich zur cranialen Computertomographie

    Energy Technology Data Exchange (ETDEWEB)

    Pumpf, K.

    1989-10-06

    Computed tomography and NMR imaging were carried out at short intervals in a group of patients known to suffer from cerebral diseases like tumours, multiple sclerosis, disseminated encephalomyelitis, ischemia, hemorrhages and hydrocephalus and subsequently compared to each other in order to define the general circumstances and disorders, in which NMR imaging may serve as the sole method of diagnosis. Furthermore the levels of performance of CT and NMR were to be evaluated on a comparative basis in patients treated at this centre. NMR, by contrast with CT, was rather sensitive a method in multiple sclerosis (84%), ischemia (83%) and former hemorrhages (100%). Those deviations between NMR and CT were less evident in cerebral tumours, the sensitivity values determined here being 98% and 89%, respectively. Nevertheless, NMR still appeared to be superior by far, as it permitted the spread of disease and individual fine structures to be more precisely evaluated. This applied, above all, to processes in the posterior cranial fossa and at the base of skull. Differences in performance were particularly drastic in multiple sclerosis, which was diagnosed by CT in no more than 18% of cases. (orig./MG).

  15. Spectroscopic (FTIR, FT-Raman, UV and NMR) investigation and NLO, HOMO-LUMO, NBO analysis of 2-Benzylpyridine based on quantum chemical calculations.

    Science.gov (United States)

    Mathammal, R; Sudha, N; Guru Prasad, L; Ganga, N; Krishnakumar, V

    2015-02-25

    In this work, the vibrational characteristics of 2-Benzylpyridine have been investigated. The structure of the molecule has been optimized and the structural characteristics of the molecule have been determined by density functional theory B3LYP method with 6-31G(d,p) basis set. The infrared and Raman spectra have been simulated from calculated intensities. Both the experimental and theoretical vibrational data confirms the presence of functional groups in the title compound. The (1)H and (13)C NMR spectra were recorded and (1)H and (13)C nuclear magnetic resonance chemical shifts of the molecule were calculated using the gauge independent atomic orbital method. UV-Visible spectrum of the title compound was recorded in the region 190-1100 nm and the electronic properties HOMO and LUMO energies were calculated by CIS approach. Nonlinear optical and thermodynamic properties were interpreted. All the calculated results were compared with the available experimental data of the title molecule. Copyright © 2014 Elsevier B.V. All rights reserved.

  16. Meta-analysis in plant pathology: synthesizing research results.

    Science.gov (United States)

    Rosenberg, M S; Garrett, K A; Su, Z; Bowden, R L

    2004-09-01

    ABSTRACT Meta-analysis is a set of statistical procedures for synthesizing research results from a number of different studies. An estimate of a statistical effect, such as the difference in disease severity for plants with or without a management treatment, is collected from each study along with a measure of the variance of the estimate of the effect. Combining results from different studies will generally result in increased statistical power so that it is easier to detect small effects. Combining results from different studies may also make it possible to compare the size of the effect as a function of other predictor variables such as geographic region or pathogen species. We present a review of the basic methodology for meta-analysis. We also present an example of meta-analysis of the relationship between disease severity and yield loss for foliar wheat diseases, based on data collected from a decade of fungicide and nematicide test results.

  17. Optimization and practical implementation of ultrafast 2D NMR experiments

    Energy Technology Data Exchange (ETDEWEB)

    Queiroz Junior, Luiz H. K., E-mail: professorkeng@gmail.com [Universidade Federal de Sao Carlos (UFSC), SP (Brazil). Departamento de Quimica; Universidade Federal de Goias (UFGO), Goiania, GO (Brazil). Inst. de Quimica; Ferreira, Antonio G. [Universidade Federal de Sao Carlos (UFSC), SP (Brazil). Departamento de Quimica; Giraudeau, Patrick [Universite de Nantes (France). CNRS, Chimie et Interdisciplinarite: Synthese, Analyse, Modelisation

    2013-09-01

    Ultrafast 2D NMR is a powerful methodology that allows recording of a 2D NMR spectrum in a fraction of second. However, due to the numerous non-conventional parameters involved in this methodology its implementation is no trivial task. Here, an optimized experimental protocol is carefully described to ensure efficient implementation of ultrafast NMR. The ultrafast spectra resulting from this implementation are presented based on the example of two widely used 2D NMR experiments, COSY and HSQC, obtained in 0.2 s and 41 s, respectively. (author)

  18. Determination of solid fat content by NMR

    International Nuclear Information System (INIS)

    Kawada, Tsukasa; Kato, Chihiro; Suzuki, Kazuaki

    1984-01-01

    To establish a standard method for determing solid fat content, the NMR method was tested at six laboratories and the results were examined for collaboration. Two types of instruments, pulse NMR and wide-line NMR were used. Standard deviation in results at six laboratories was less than 1.5 for the step wise method, but more than 1.5 for the rapid method. The standard deviation in results at a single laboratory was much less than either of these cases. No significant difference could be observed in the values obtained using both instruments. Solid fat content values measured for a mixture of fully hydrogenated rapeseed and rapeseed oil agreed well with the percentage of solid by weight. (author)

  19. Create, run, share, publish, and reference your LC-MS, FIA-MS, GC-MS, and NMR data analysis workflows with the Workflow4Metabolomics 3.0 Galaxy online infrastructure for metabolomics.

    Science.gov (United States)

    Guitton, Yann; Tremblay-Franco, Marie; Le Corguillé, Gildas; Martin, Jean-François; Pétéra, Mélanie; Roger-Mele, Pierrick; Delabrière, Alexis; Goulitquer, Sophie; Monsoor, Misharl; Duperier, Christophe; Canlet, Cécile; Servien, Rémi; Tardivel, Patrick; Caron, Christophe; Giacomoni, Franck; Thévenot, Etienne A

    2017-12-01

    Metabolomics is a key approach in modern functional genomics and systems biology. Due to the complexity of metabolomics data, the variety of experimental designs, and the multiplicity of bioinformatics tools, providing experimenters with a simple and efficient resource to conduct comprehensive and rigorous analysis of their data is of utmost importance. In 2014, we launched the Workflow4Metabolomics (W4M; http://workflow4metabolomics.org) online infrastructure for metabolomics built on the Galaxy environment, which offers user-friendly features to build and run data analysis workflows including preprocessing, statistical analysis, and annotation steps. Here we present the new W4M 3.0 release, which contains twice as many tools as the first version, and provides two features which are, to our knowledge, unique among online resources. First, data from the four major metabolomics technologies (i.e., LC-MS, FIA-MS, GC-MS, and NMR) can be analyzed on a single platform. By using three studies in human physiology, alga evolution, and animal toxicology, we demonstrate how the 40 available tools can be easily combined to address biological issues. Second, the full analysis (including the workflow, the parameter values, the input data and output results) can be referenced with a permanent digital object identifier (DOI). Publication of data analyses is of major importance for robust and reproducible science. Furthermore, the publicly shared workflows are of high-value for e-learning and training. The Workflow4Metabolomics 3.0 e-infrastructure thus not only offers a unique online environment for analysis of data from the main metabolomics technologies, but it is also the first reference repository for metabolomics workflows. Copyright © 2017 Elsevier Ltd. All rights reserved.

  20. Addressing the overlap problem in the quantitative analysis of two dimensional NMR spectra: Application to 15N relaxation measurements

    International Nuclear Information System (INIS)

    Tugarinov, Vitali; Choy, W.-Y.; Kupce, Eriks; Kay, Lewis E.

    2004-01-01

    A quantitative analysis of 2D 1 H- 15 N spectra is often complicated by resonance overlap. Here a simple method is presented for resolving overlapped correlations by recording 2D projection planes from HNCO data sets. Applications are presented involving the measurement of 15 N T 1ρ relaxation rates in a high molecular weight protein, malate synthase G, and in a system that exchanges between folded and unfolded states, the drkN SH3 domain. By supplementing relaxation data recorded in the conventional way as a series of 2D 1 H- 15 N data sets with a series of a pair of projection planes the number of dynamics probes is increased significantly for both systems studied

  1. A multivariate statistical analysis coming from the NMR metabolic profile of cherry tomatoes (The Sicilian Pachino case)

    Science.gov (United States)

    Mallamace, Domenico; Corsaro, Carmelo; Salvo, Andrea; Cicero, Nicola; Macaluso, Andrea; Giangrosso, Giuseppe; Ferrantelli, Vincenzo; Dugo, Giacomo

    2014-05-01

    We have studied by means of High Resolution Magic Angle Spinning Nuclear Magnetic Resonance the metabolic profile of the famous Sicilian cherry tomato of Pachino. Thanks to its organoleptic and healthy properties, this particular foodstuff was the first tomato accredited by the European PGI (Protected Geographical Indication) certification of quality. Due to the relatively high price of the final product commercial frauds originated in the Italian and international markets. Hence, there is a growing interest to develop analytical techniques able to predict the origin of a tomato sample, indicating whether or not it originates from the area of Pachino, Sicily (Italy). In this paper we have determined the molar concentration of the metabolites constituent the PGI cherry tomato of Pachino. Furthermore, by means of a multivariate statistical analysis we have identified which metabolites are relevant for sample differentiation.

  2. Characteristics ofXanthosoma sagittifoliumroots during cooking, using physicochemical analysis, uniaxial compression, multispectral imaging and low field NMR spectroscopy.

    Science.gov (United States)

    Boakye, Abena Achiaa; Gudjónsdóttir, María; Skytte, Jacob Lercke; Chronakis, Ioannis S; Wireko-Manu, Faustina Dufie; Oduro, Ibok

    2017-08-01

    To effectively promote the industrial utilization of cocoyam ( Xanthosoma sagittifolium ) roots for enhanced food sustainability and security, there is a need to study their molecular, mechanical and physicochemical properties in detail. The physicochemical and textural characteristics of the red and white varieties of cocoyam roots were thus analysed by low field nuclear magnetic resonance relaxometry, multispectral imaging, uniaxial compression testing, and relevant physicochemical analysis in the current study. Both varieties had similar dry matter content, as well as physical and mechanical properties. However, up to four fast-interacting water populations were observed in the roots, dependent on the root variety and their degree of gelatinization during cooking. Changes in the relaxation parameters indicated weak gelatinization of starch at approximately 80 °C in both varieties. However, shorter relaxation times and a higher proportion of restricted water in the white variety indicated that this variety was slightly more sensitive towards gelatinization. A strong negative correlation existed between dry matter and all multispectral wavelengths >800 nm, suggesting the potential use of that spectral region for rapid analysis of dry matter and water content of the roots. The small, but significant differences in the structural and gelatinization characteristics of the two varieties indicated that they may not be equally suited for further processing, e.g. to flours or starches. Processors thus need to choose their raw materials wisely dependent on the aimed product characteristics. However, the spectroscopic methods applied in the study were shown to be effective in assessing important quality attributes during cooking of the roots.

  3. 27 Al MAS NMR Studies of HBEA Zeolite at Low to High Magnetic Fields

    Energy Technology Data Exchange (ETDEWEB)

    Hu, Jian Z.; Wan, Chuan; Vjunov, Aleksei; Wang, Meng; Zhao, Zhenchao; Hu, Mary Y.; Camaioni, Donald M.; Lercher, Johannes A.

    2017-06-01

    27Al single pulse (SP) MAS NMR spectra of HBEA zeolites with high Si/Al ratios of 71 and 75 were obtained at three magnetic field strengths of 7.05, 11.75 and 19.97 T. High field 27Al MAS NMR spectra acquired at 19.97 T show significantly improved spectral resolution, resulting in at least two well-resolved tetrahedral-Al NMR peaks. Based on the results obtained from 27Al MAS and MQMAS NMR acquired at 19.97 T, four different quadrupole peaks are used to deconvolute the 27Al SP MAS spectra acquired at vari-ous fields by using the same set of quadrupole coupling constants, asymmetric parameters and relative integrated peak intensities for the tetrahedral Al peaks. The line shapes of individual peaks change from typical quadrupole line shape at low field to essentially symmetrical line shapes at high field. We demonstrate that for fully hydrated HBEA zeolites the effect of second order quadrupole interaction can be ignored and quantitative spectral analysis can be performed by directly fitting the high field spectra using mixed Gaussian/Lorentzian line shapes. Also, the analytical steps described in our work allow direct assignment of spectral intensity to individual Al tetrahedral sites (T-sites) of zeolite HBEA. Finally, the proposed concept is suggested generally applicable to other zeo-lite framework types, thus, allowing a direct probing of Al distributions by NMR spectroscopic methods in zeolites with high confi-dence.

  4. Proton NMR studies of functionalized nanoparticles in aqueous environments

    Science.gov (United States)

    Tataurova, Yulia Nikolaevna

    in high-resolution NMR spectra. This technique is selective for protons on the surface organic functional groups due to their motional averaging in solution. In this study, 1H solution NMR spectroscopy was used to investigate the interface of the organic functional groups in D2O. The pKa for these functional groups covalently bound to the surface of nanoparticles was determined using an NMR-pH titration method based on the variation in the proton chemical shift for the alkyl group protons closest to the amine group with pH. The adsorption of toxic contaminants (chromate and arsenate anions) on the surface of functionalized silicalite-1 and mesoporous silica nanoparticles has been studied by 1H solution NMR spectroscopy. With this method, the surface bound contaminants are detected. The analysis of the intensity and position of these peaks allows quantitative assessment of the relative amounts of functional groups with adsorbed metal ions. These results demonstrate the sensitivity of solution NMR spectroscopy to the electronic environment and structure of the surface functional groups on porous nanomaterials.

  5. NMR characterization of polymers: Review and update

    Science.gov (United States)

    NMR spectroscopy is a major technique for the characterization and analysis of polymers. A large number of methodologies have been developed in both the liquid and the solid state, and the literature has grown considerably (1-5). The field now covers a broad spectrum of activities, including polym...

  6. Advanced Laboratory NMR Spectrometer with Applications.

    Science.gov (United States)

    Biscegli, Clovis; And Others

    1982-01-01

    A description is given of an inexpensive nuclear magnetic resonance (NMR) spectrometer suitable for use in advanced laboratory courses. Applications to the nondestructive analysis of the oil content in corn seeds and in monitoring the crystallization of polymers are presented. (SK)

  7. Chemical characterization of a prominent phosphomonoester resonance from mammalian brain. 31P and 1H NMR analysis at 4.7 and 14.1 tesla

    Science.gov (United States)

    Pettegrew, J. W.; Kopp, S. J.; Dadok, J.; Minshew, N. J.; Feliksik, J. M.; Glonek, T.; Cohen, M. M.

    A prominent 31P NMR resonance at 3.84 ppm in mammalian brain has been identified as ethanolamine phosphate. The identification was based on 1H and 31P NMR findings (including pH titrations) at 4.7 and 14.1 T, as well as thin-layer chromatography studies. We previously incorrectly assigned the 3.84 ppm resonance to ribose-5-phosphate. The incorrect assignment occurred because the two compounds have very similar 31P chemical shifts, and because we did not carefully consider the effects of counter ions and ionic strengths when interpreting the 31P chemical shifts. In separate preliminary studies we have demonstrated ethanolamine phosphate to be high in immature developing brain and in the degenerating brain of Alzheimer's and Huntington's disease patients. Ethanolamine phosphate may therefore serve as a sensitive marker of membrane phospholipid turnover for both in vitro and in vivo31P NMR studies.

  8. Comparison of analysis results with experimental results for ENEA and CRIEPI rubber bearings

    International Nuclear Information System (INIS)

    Yoo, B.; Lee, J.H.; Koo, G.H.

    1993-01-01

    In this paper, the preliminary structural analyses of ENEA HDRB and CRIEPI NRB were performed by using computer code ABAQUS, and the analysis results were compared with the test results provided by Italy and Japan thru IAEA. The test data for the rubbers used for the fabrication of bearings were also provided thru IAEA, and were utilized for the formulation of the rubber models for the analyses. The analyses performed for the rubber bearings are for the combined compression and shear and for the compression. The analysis results show a good agreement in shear strains when compared with the test results of HDRB and NRB for the combined compression and shear and for the compression benchmarks, but show relatively smaller responses in displacements for the compression with offsets benchmarks. (author)

  9. Ring current shifts in {sup 19}F-NMR of membrane proteins

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Dongsheng, E-mail: liudsh@shanghaitech.edu.cn; Wüthrich, Kurt, E-mail: kwuthrich@shanghaitech.edu.cn [ShanghaiTech University, iHuman Institute (China)

    2016-05-15

    Fluorine-19 NMR markers are attractive reporter groups for use in studies of complex biomacromolecular systems, in particular also for studies of function-related conformational equilibria and rate processes in membrane proteins. Advantages of {sup 19}F-NMR probes include high sensitivity of the {sup 19}F chemical shifts to variations in the non-covalent environment. Nonetheless, in studies of G protein-coupled receptors (GPCR) we encountered situations where {sup 19}F chemical shifts were not responsive to conformational changes that had been implicated by other methods. This prompted us to examine possible effects of aromatic ring current fields on the chemical shifts of {sup 19}F-NMR probes used in GPCRs. Analysis of previously reported {sup 19}F-NMR data on the β{sub 2}-adrenergic receptor and mammalian rhodopsin showed that all {sup 19}F-labeling sites which manifested conformational changes are located near aromatic residues. Although ring current effects are small when compared to other known non-covalent effects on {sup 19}F chemical shifts, there is thus an indication that their contributions are significant when studying activation processes in GPCRs, since the observed activation-related {sup 19}F-NMR chemical shifts are comparable in size to the calculated ring current shifts. Considering the impact of ring current shifts may thus be helpful in identifying promising indigenous or engineered labeling sites for future {sup 19}F-NMR studies of GPCR activation, and novel information may be obtained on the nature of conformational rearrangements near the {sup 19}F-labels. It will then also be interesting to see if the presently indicated role of ring current shifts in membrane protein studies with {sup 19}F-NMR markers can be substantiated by a more extensive data base resulting from future studies.

  10. Median Modified Wiener Filter for nonlinear adaptive spatial denoising of protein NMR multidimensional spectra

    KAUST Repository

    Cannistraci, Carlo Vittorio

    2015-01-26

    Denoising multidimensional NMR-spectra is a fundamental step in NMR protein structure determination. The state-of-the-art method uses wavelet-denoising, which may suffer when applied to non-stationary signals affected by Gaussian-white-noise mixed with strong impulsive artifacts, like those in multi-dimensional NMR-spectra. Regrettably, Wavelet\\'s performance depends on a combinatorial search of wavelet shapes and parameters; and multi-dimensional extension of wavelet-denoising is highly non-trivial, which hampers its application to multidimensional NMR-spectra. Here, we endorse a diverse philosophy of denoising NMR-spectra: less is more! We consider spatial filters that have only one parameter to tune: the window-size. We propose, for the first time, the 3D extension of the median-modified-Wiener-filter (MMWF), an adaptive variant of the median-filter, and also its novel variation named MMWF*. We test the proposed filters and the Wiener-filter, an adaptive variant of the mean-filter, on a benchmark set that contains 16 two-dimensional and three-dimensional NMR-spectra extracted from eight proteins. Our results demonstrate that the adaptive spatial filters significantly outperform their non-adaptive versions. The performance of the new MMWF* on 2D/3D-spectra is even better than wavelet-denoising. Noticeably, MMWF* produces stable high performance almost invariant for diverse window-size settings: this signifies a consistent advantage in the implementation of automatic pipelines for protein NMR-spectra analysis.

  11. NMR-based phytochemical analysis of Vitis vinifera cv Falanghina leaves. Characterization of a previously undescribed biflavonoid with antiproliferative activity.

    Science.gov (United States)

    Tartaglione, Luciana; Gambuti, Angelita; De Cicco, Paola; Ercolano, Giuseppe; Ianaro, Angela; Taglialatela-Scafati, Orazio; Moio, Luigi; Forino, Martino

    2018-03-01

    Vitis vinifera cv Falanghina is an ancient grape variety of Southern Italy. A thorough phytochemical analysis of the Falanghina leaves was conducted to investigate its specialised metabolite content. Along with already known molecules, such as caftaric acid, quercetin-3-O-β-d-glucopyranoside, quercetin-3-O-β-d-glucuronide, kaempferol-3-O-β-d-glucopyranoside and kaempferol-3-O-β-d-glucuronide, a previously undescribed biflavonoid was identified. For this last compound, a moderate bioactivity against metastatic melanoma cells proliferation was discovered. This datum can be of some interest to researchers studying human melanoma. The high content in antioxidant glycosylated flavonoids supports the exploitation of grape vine leaves as an inexpensive source of natural products for the food industry and for both pharmaceutical and nutraceutical companies. Additionally, this study offers important insights into the plant physiology, thus prompting possible technological researches of genetic selection based on the vine adaptation to specific pedo-climatic environments. Copyright © 2017 Elsevier B.V. All rights reserved.

  12. Characterization of high boiling fossil fuel distillates via 1H and 13C NMR analysis. Final report, July 1, 1978-June 30, 1979

    International Nuclear Information System (INIS)

    Berlin, K.D.; O'Donnell, D.J.; Sigle, S.; Sturm, G.P. Jr.

    1979-09-01

    High-boiling (535 to 675 0 C) distillates of Wilmington (Calif., USA) and Gach Saran (Iran) crude oils were separated into saturate, monoaromatic, diaromatic and polyaromatic-polar adsorption fractions by a silica gel-alumina dual packed gel chromatography column. These fractions were further separated on the basis of molecular volume by gel-permeation chromatography (GPC). All chromatographic separations were done by the Bartlesville Energy Technology Center of the DOE. Samples selected by the DOE were then analyzed by 13 C and 1 H NMR spectroscopy. The per cent fraction of aromatic carbons (Ar-C) of the total carbon content of a given series of GPC fractions obtained directly from the 13 C NMR spectra showed a significant range of values (e.g. 13.2% to 29.2%) within each series. Furthermore, the values of Ar-C within a series of GPC fractions showed a maximum in each case. No corresponding maximum was observed in the 1 H NMR spectra for the per cent fraction of aromatic proton (Ar-H) content compared to the total proton content in any of the GPC fraction series. Signals observed in the 13 C NMR spectra confirmed the presence of aliphatic chains attached to aromatic structures in the monoaromatic, diaromatic and polyaromatic-polar GPC series of each distillate. Well defined signals not attributable to straight-chain aliphatic material were also observed in the 13 C NMR spectra. Comparison of the 13 C NMR signals with those spectra of model compounds obtained experimentally and with the spectra of appropriate systems in the literature strongly suggested the presence of saturated terpenoid-like structures, as well as the presence of methyl groups in sterically hindered positions on an aromatic ring system

  13. Results of special radiation measurements resulting from the Chernobyl accident and regional analysis of environmental radioactivity

    International Nuclear Information System (INIS)

    1986-07-01

    This report of the SCPRI exposes an interpretation of the results concerning the monitoring of the environmental radioactivity in France following Chernobyl accident. Atmospheric dusts, milk and milk products, vegetables, water and various beverages are analyzed. More than 1500 additional food samples are presented. Regional analysis of radioactivity and human gamma-spectrometric investigations are included [fr

  14. Rapid mass spectrometric analysis of 15N-Leu incorporation fidelity during preparation of specifically labeled NMR samples

    DEFF Research Database (Denmark)

    Truhlar, Stephanie M E; Cervantes, Carla F; Torpey, Justin W

    2008-01-01

    . MALDI TOF-TOF MS/MS data provide additional information that shows where the "extra" (15)N labels are incorporated, which can be useful in confirming ambiguous assignments. The described procedure provides a rapid technique to monitor the fidelity of selective labeling that does not require a lot...... during protein expression is a common problem. We describe a rapid method to evaluate the fidelity of specific (15)N-amino acid incorporation. The selectively labeled protein is proteolyzed, and the resulting peptides are analyzed using MALDI mass spectrometry. The (15)N incorporation is determined...

  15. Quantitative analysis of water heavy by NMR spectroscopy; aplicacion de la resonancia magnetica nuclear al analisis cuantitativo de agua pesada

    Energy Technology Data Exchange (ETDEWEB)

    Gomez Gil, V.

    1975-07-01

    Nuclear Magnetic Resonance has been applied to a wide variety of quantitative problems. A typical example has been the determination of isotopic composition. In this paper two different analytical methods for the determination of water in deuterium oxide are described. The first one, employs acetonitril as an internal standard compound and in the second one calibration curve of signal integral curve versus amount of D{sub 2}O is constructed. Both methods give results comparable to those of mass spectrometry of IR spectroscopy. (Author) 5 refs.

  16. Spectroscopic (FT-IR, FT-Raman, UV and NMR) investigation and NLO, HOMO-LUMO, NBO analysis of organic 2,4,5-trichloroaniline.

    Science.gov (United States)

    Govindarajan, M; Karabacak, M; Periandy, S; Tanuja, D

    2012-11-01

    In this work, the experimental and theoretical study on the molecular structure and vibrational spectra of 2,4,5-trichloroaniline (C(6)H(4)NCl(3), abbreviated as 2,4,5-TClA) were studied. The FT-IR and FT-Raman spectra were recorded. The molecular geometry and vibrational frequencies in the ground state were calculated by using the Hartree-Fock (HF) and density functional theory (DFT) methods (B3LYP) with 6-311++G(d,p) basis set. Comparison of the observed fundamental vibrational frequencies of 2,4,5-TClA with calculated results by HF and DFT indicates that B3LYP is superior to HF method for molecular vibrational problems. The difference between the observed and scaled wavenumber values of most of the fundamentals is very small. The theoretically predicted FT-IR and FT-Raman spectra of the title molecule have been constructed. A study on the electronic properties, such as HOMO and LUMO energies, were performed by time-dependent DFT (TD-DFT) approach. Besides, molecular electrostatic potential (MEP) and thermodynamic properties were performed. The electric dipole moment (μ) and the first hyperpolarizability (β) values of the investigated molecule were computed using ab initio quantum mechanical calculations. The calculated results also show that the 2,4,5-TClA molecule may have microscopic nonlinear optical (NLO) behavior with non-zero values. Mulliken atomic charges of 2,4,5-TClA was calculated and compared with aniline and chlorobenzene molecules. The (13)C nuclear magnetic resonance (NMR) chemical shifts of the molecule were calculated by the gauge independent atomic orbital (GIAO) method and compared with experimental results. Copyright © 2012 Elsevier B.V. All rights reserved.

  17. NMR Studies of Peroxidases.

    Science.gov (United States)

    Veitch, Nigel Charles

    Available from UMI in association with The British Library. Requires signed TDF. Peroxidases are a haem-containing group of enzymes with a wide diversity of function within biological systems. While a common characteristic is the ability to catalyse the conversion of hydrogen peroxide to water, it is the accompanying processes of hormone synthesis and degradation which have generated such a high level of interest. However, information at the molecular level is limited to a single well-resolved crystal structure, that of yeast cytochrome c peroxidase. This thesis presents a strategy for the investigation of peroxidase structure and function based on proton nuclear magnetic resonance spectroscopy, a technique which has the ability to address aspects of both protein structure and protein dynamics in solution. The application of one- and two-dimensional NMR techniques has been developed in the context of plant peroxidases, notably the isoenzyme HRP-C derived from the horseradish root. Characterisation of the proton NMR spectra of HRP -C in resting and ligated states provided new information enabling the structure of the binding site for aromatic donor molecules, such as indole-3-propionic, ferulic and benzhydroxamic acids, to be resolved. In order to overcome difficulties encountered with a protein of the complexity of peroxidase, additional information was obtained from chemical shift parameters and the use of peroxidase variants produced by site-directed mutagenesis. A comparative study using NMR spectroscopy was undertaken for wild-type recombinant HRP-C expressed in Escherichia coli, and two protein variants with substitutions made to residues located on the distal side of the haem pocket, Phe41 to Val and Arg38 to Lys. NMR analyses of a plant peroxidase from barley grains and the fungal peroxidase from Coprinus cinereus were also successful using methods conceived with HRP-C. Examination of three specifically constructed recombinant protein variants of C. cinereus

  18. Conformational analysis of the Sda determinant-containing tetrasaccharide and two mimics in aqueous solution by using 1H NMR ROESY spectroscopy in combination with MD simulations

    International Nuclear Information System (INIS)

    Blanco, Jose L. Jimenez; Rooijen, Johannes J.M. van; Erbel, Paul J.A.; Leeflang, Bas R.; Kamerling, Johannis P.; Vliegenthart, Johannes F.G.

    2000-01-01

    The conformational behaviour of the spacer-linked synthetic Sd a tetrasaccharide β-d-GalpNAc-(1 → 4)-[α-Neu5Ac-(2 → 3)]-β-d-Galp-(1 → 4)-β-d-GlcpNAc-(1 → O) (CH 2 ) 5 NH 2 (1) and the two mimics β-d-Galp-(1 → 4)-[α-Neu5Ac-(2 → 3)]-β-d-Galp-(1 → 4)-β-d-GlcpNAc-(1 → O)(CH 2 ) 5 NH 2 (2) and β-d-GlcpNAc-(1 → 4)-[α-Neu5Ac-(2 → 3)]-β-d-Galp-(1 → 4)-β-d-GlcpNAc-(1 → O) (CH 2 ) 5 NH 2 (3) were investigated by 1 H NMR spectroscopy in combination with molecular dynamics (MD) simulations in water. Experimental 2D 1 H ROESY cross-peak intensities (ROEs) of the tetrasaccharides were compared with calculated ROEs derived from MD trajectories using the CROSREL program. Analysis of these data indicated that the oligosaccharidic skeletons of the compounds 1-3 are rather rigid, especially the β-d-Hex(NAc)-(1 → 4)-[α-Neu5Ac-(2 → 3)]-β-d-Galp fragments. The α- Neu5-Ac-(2 → 3)-β-d-Galp linkage occurred in two different energy minima in the three-dimensional structure of the compounds 1-3 in aqueous solution. Experimental data and dynamics simulations supported the finding that the higher energy rotamer (CHEAT forcefield) was abundant in compounds 1 and 3 due to the existence of a hydrogen bond between the carboxyl group of the sialic acid and the acetamido group of the terminal monosaccharide (GalNAc or GlcNAc) unit. The conformational similarity between 1 and 3 leads to the suggestion that also their activities will be alike.

  19. NMR Analysis of Amide Hydrogen Exchange Rates in a Pentapeptide-Repeat Protein from A. thaliana.

    Science.gov (United States)

    Xu, Shenyuan; Ni, Shuisong; Kennedy, Michael A

    2017-05-23

    At2g44920 from Arabidopsis thaliana is a pentapeptide-repeat protein (PRP) composed of 25 repeats capped by N- and C-terminal α-helices. PRP structures are dominated by four-sided right-handed β-helices typically consisting of mixtures of type II and type IV β-turns. PRPs adopt repeated five-residue (Rfr) folds with an Rfr consensus sequence (STAV)(D/N)(L/F)(S/T/R)(X). Unlike other PRPs, At2g44920 consists exclusively of type II β-turns. At2g44920 is predicted to be located in the thylakoid lumen although its biochemical function remains unknown. Given its unusual structure, we investigated the biophysical properties of At2g44920 as a representative of the β-helix family to determine if it had exceptional global stability, backbone dynamics, or amide hydrogen exchange rates. Circular dichroism measurements yielded a melting point of 62.8°C, indicating unexceptional global thermal stability. Nuclear spin relaxation measurements indicated that the Rfr-fold core was rigid with order parameters ranging from 0.7 to 0.9. At2g44920 exhibited a striking range of amide hydrogen exchange rates spanning 10 orders of magnitude, with lifetimes ranging from minutes to several months. A weak correlation was found among hydrogen exchange rates, hydrogen bonding energies, and amino acid solvent-accessible areas. Analysis of contributions from fast (approximately picosecond to nanosecond) backbone dynamics to amide hydrogen exchange rates revealed that the average order parameter of amides undergoing fast exchange was significantly smaller compared to those undergoing slow exchange. Importantly, the activation energies for amide hydrogen exchange were found to be generally higher for the slowest exchanging amides in the central Rfr coil and decreased toward the terminal coils. This could be explained by assuming that the concerted motions of two preceding or following coils required for hydrogen bond disruption and amide hydrogen exchange have a higher activation energy

  20. Describing the homeless mentally ill: cluster analysis results.

    Science.gov (United States)

    Mowbray, C T; Bybee, D; Cohen, E

    1993-02-01

    Presented descriptive data on a group of homeless, mentally ill individuals (N = 108) served by a two-site demonstration project, funded by NIMH. Comparing results with those from other studies of this population produced some differences and some similarities. Cluster analysis techniques were applied to the data, producing a 4-group solution. Data validating the cluster solution are presented. It is suggested that the cluster results provide a more meaningful and useful method of understanding the descriptive data. Results suggest that while the population of individuals served as homeless and mentally ill is quite heterogeneous, many have well-developed functioning skills--only one cluster, making up 35.2% of the sample, fits the stereotype of the aggressive, psychotic individual with skill deficits in many areas. Further discussion is presented concerning the implications of the cluster analysis results for demonstrating contextual effects and thus better interpreting research results from other studies and assisting in future services planning.

  1. Crystal structure and dynamic NMR studies of octaacetyl-tetra(propyl)calix[4]resorcinarene

    Science.gov (United States)

    Velásquez-Silva, Astrid; Cortés, Brian; Rivera-Monroy, Zuly J.; Pérez-Redondo, Adrián; Maldonado, Mauricio

    2017-06-01

    The reaction between C-tetra(propyl)calix[4]resorcinarene (1) and acetic anhydride in pyridine results in the formation of octaacetyl-tetra(propyl)calix[4]resorcinarene (2). The structure was determined using FT-IR, 1H-NMR and 13C-NMR. The dynamic 1H-NMR of acetylated resorcinarene was studied by means of variable temperature in a CDCl3 solution and revealed that two conformers are formed in the solution. Boat conformations for acetylated resorcinarene exhibited a rapid interconversion at low temperatures, and the activation barrier for the pseudorotation was determined (54.72 kJmol-1). The acetylated resorcinarene 2 was also characterized by an X-ray crystal structure determination. This analysis indicated a boat configuration for the macrocycle skeleton in the solid state. Csbnd H⋯O hydrogen bonding interactions were observed in the packing of compound.

  2. Mapping the variation of the carrot metabolome using 1H NMR spectroscopy and consensus PCA.

    Science.gov (United States)

    Clausen, Morten Rahr; Edelenbos, Merete; Bertram, Hanne Christine

    2014-05-14

    Genetic variation is the most influential factor for carrot (Daucus carota L.) composition. However, difference in metabolite content between carrot varieties has not been described by NMR, although primary metabolites are important for human health and sensory properties. The aim of the present study was to investigate the effect of genotype on carrot metabolite composition using a (1)H NMR-based metabolomics approach. After extraction using aqueous and organic solvents, 25 hydrophilic metabolites, β-carotene, sterols, triacylglycerols, and phospholipids were detected. Multiblock PCA showed that three principal components could be identified for classification of the five carrot varieties using different spectroscopic regions and the results of the two solvent extraction methods as blocks. The varieties were characterized by differences in carbohydrate, amino acid, nucleotide, fatty acid, sterol, and β-carotene contents. (1)H NMR spectroscopy coupled with multiblock data analysis was an efficient and useful tool to map the carrot metabolome and identify genetic differences between varieties.

  3. Solid-state NMR studies of form I of atorvastatin calcium.

    Science.gov (United States)

    Wang, Wei David; Gao, Xudong; Strohmeier, Mark; Wang, Wei; Bai, Shi; Dybowski, Cecil

    2012-03-22

    Solid-state (13)C, (19)F, and (15)N magic angle spinning NMR studies of Form I of atorvastatin calcium are reported, including chemical shift tensors of all resolvable carbon sites and fluorine sites. The complete (13)C and (19)F chemical shift assignments are given based on an extensive analysis of (13)C-(1)H HETCOR and (13)C-(19)F HETCOR results. The solid-state NMR data indicate that the asymmetric unit of this material contains two atorvastatin molecules. A possible structure of Form I of atorvastatin calcium (ATC-I), derived from solid-state NMR data and density functional theory calculations of various structures, is proposed for this important active pharmaceutical ingredient (API).

  4. Preliminary results of the analysis of the BATSE TTE data

    Science.gov (United States)

    Horváth, I.; Norris, J. P.; Scargle, J. D.; Balázs, L. G.

    2005-05-01

    The Compton Gamma Ray Observatory (CGRO) observed many types of data and one of them is the time-tagged photon events (TTE data). We use the Bayesian block analysis, using Bayesian statistics, analyses the TTE data. Our results; calculations of duration (T100), count rates (burst photon numbers in different channels) and count peaks (in 64, 16 and 4ms). We present the duration, the peak duration and the distance between peaks distributions. Principal Component Analysis (PCA) has been also applied. The PCA shows interesting results, such as channel 4 (highest energy channel) probably is very important.

  5. Electronic structure investigations of 4-aminophthal hydrazide by UV-visible, NMR spectral studies and HOMO-LUMO analysis by ab initio and DFT calculations.

    Science.gov (United States)

    Sambathkumar, K; Jeyavijayan, S; Arivazhagan, M

    2015-08-05

    Combined experimental and theoretical studies were conducted on the molecular structure and vibrational spectra of 4-AminoPhthalhydrazide (APH). The FT-IR and FT-Raman spectra of APH were recorded in the solid phase. The molecular geometry and vibrational frequencies of APH in the ground state have been calculated by using the ab initio HF (Hartree-Fock) and density functional methods (B3LYP) invoking 6-311+G(d,p) basis set. The optimized geometric bond lengths and bond angles obtained by HF and B3LYP method show best agreement with the experimental values. Comparison of the observed fundamental vibrational frequencies of APH with calculated results by HF and density functional methods indicates that B3LYP is superior to the scaled Hartree-Fock approach for molecular vibrational problems. The difference between the observed and scaled wave number values of most of the fundamentals is very small. A detailed interpretation of the NMR spectra of APH was also reported. The theoretical spectrograms for infrared and Raman spectra of the title molecule have been constructed. UV-vis spectrum of the compound was recorded and the electronic properties, such as HOMO and LUMO energies, were performed by time dependent density functional theory (TD-DFT) approach. Finally the calculations results were applied to simulated infrared and Raman spectra of the title compound which show good agreement with observed spectra. And the temperature dependence of the thermodynamic properties of constant pressure (Cp), entropy (S) and enthalpy change (ΔH0→T) for APH were also determined. Copyright © 2015 Elsevier B.V. All rights reserved.

  6. Early Effect of Amyloid β-Peptide on Hippocampal and Serum Metabolism in Rats Studied by an Integrated Method of NMR-Based Metabolomics and ANOVA-Simultaneous Component Analysis

    Directory of Open Access Journals (Sweden)

    Yao Du

    2017-01-01

    Full Text Available Amyloid β (Aβ deposition has been implicated in the pathogenesis of Alzheimer’s disease. However, the early effect of Aβ deposition on metabolism remains unclear. In the present study, thus, we explored the metabolic changes in the hippocampus and serum during first 2 weeks of Aβ25–35 injection in rats by using an integrated method of NMR-based metabolomics and ANOVA-simultaneous component analysis (ASCA. Our results show that Aβ25–35 injection, time, and their interaction had statistically significant effects on the hippocampus and serum metabolome. Furthermore, we identified key metabolites that mainly contributed to these effects. After Aβ25–35 injection from 1 to 2 weeks, the levels of lactate, N-acetylaspartate, creatine, and taurine were decreased in rat hippocampus, while an increase in lactate and decreases in LDL/VLDL and glucose were observed in rat serum. Therefore, we suggest that the reduction in energy and lipid metabolism as well as an increase in anaerobic glycolysis may occur at the early stage of Aβ25–35 deposition.

  7. Organ-Specific Differential NMR-Based Metabonomic Analysis of Soybean [Glycine max (L. Merr.] Fruit Reveals the Metabolic Shifts and Potential Protection Mechanisms Involved in Field Mold Infection

    Directory of Open Access Journals (Sweden)

    Wen-yu Yang

    2017-04-01

    Full Text Available Prolonged, continuous rainfall is the main climatic characteristic of autumn in Southwest China, and it has been found to cause mildew outbreaks in pre-harvest soybean fields. Low temperature and humidity (LTH stress during soybean maturation in the field promotes pre-harvest mildew, resulting in damage to different organs of soybean fruits to different extents, but relatively little information on the resistance mechanisms in these fruits is available. Therefore, to understand the metabolic responses of soybean fruits to field mold (FM, the metabonomic variations induced by LTH were characterized using proton nuclear magnetic resonance spectroscopy (1H-NMR, and the primary metabolites from the pod, seed coat and cotyledon of pre-harvest soybean were quantified. Analysis of FM-damaged soybean germplasms with different degrees of resistance to FM showed that extracts were dominated by 66 primary metabolites, including amino acids, organic acids and sugars. Each tissue had a characteristic metabolic profile, indicating that the metabolism of proline in the cotyledon, lysine in the seed coat, and sulfur in the pod play important roles in FM resistance. The primary-secondary metabolism interface and its potential contribution to FM resistance was investigated by targeted analyses of secondary metabolites. Both the seed coat and the pod have distinct but nonexclusive metabolic responses to FM, and these are functionally integrated into FM resistance mechanisms.

  8. Recommended strategies for spectral processing and post-processing of 1D 1H-NMR data of biofluids with a particular focus on urine

    KAUST Repository

    Emwas, Abdul-Hamid M.

    2018-02-12

    1H NMR spectra from urine can yield information-rich data sets that offer important insights into many biological and biochemical phenomena. However, the quality and utility of these insights can be profoundly affected by how the NMR spectra are processed and interpreted. For instance, if the NMR spectra are incorrectly referenced or inconsistently aligned, the identification of many compounds will be incorrect. If the NMR spectra are mis-phased or if the baseline correction is flawed, the estimated concentrations of many compounds will be systematically biased. Furthermore, because NMR permits the measurement of concentrations spanning up to five orders of magnitude, several problems can arise with data analysis. For instance, signals originating from the most abundant metabolites may prove to be the least biologically relevant while signals arising from the least abundant metabolites may prove to be the most important but hardest to accurately and precisely measure. As a result, a number of data processing techniques such as scaling, transformation and normalization are often required to address these issues. Therefore, proper processing of NMR data is a critical step to correctly extract useful information in any NMR-based metabolomic study. In this review we highlight the significance, advantages and disadvantages of different NMR spectral processing steps that are common to most NMR-based metabolomic studies of urine. These include: chemical shift referencing, phase and baseline correction, spectral alignment, spectral binning, scaling and normalization. We also provide a set of recommendations for best practices regarding spectral and data processing for NMR-based metabolomic studies of biofluids, with a particular focus on urine.

  9. Toxic actions of dinoseb in medaka (Oryzias latipes) embryos as determined by in vivo 31P NMR, HPLC-UV and 1H NMR metabolomics.

    Science.gov (United States)

    Viant, Mark R; Pincetich, Christopher A; Hinton, David E; Tjeerdema, Ronald S

    2006-03-10

    Changes in metabolism of Japanese medaka (Oryzias latipes) embryos exposed to dinoseb (2-sec-butyl-4,6-dinitrophenol), a substituted dinitrophenol herbicide, were determined by in vivo (31)P NMR, high-pressure liquid chromatography (HPLC)-UV, and (1)H NMR metabolomics. ATP and phosphocreatine (PCr) metabolism were characterized within intact embryos by in vivo (31)P NMR; concentrations of ATP, GTP, ADP, GDP, AMP and PCr were determined by HPLC-UV; and changes in numerous polar metabolites were characterized by (1)H NMR-based metabolomics. Rangefinding exposures determined two sublethal doses of dinoseb, 50 and 75 ppb, in which embryos survived from 1-day post fertilization (DPF) through the duration of embryogenesis. In vivo (31)P NMR data were acquired from 900 embryos in 0, 50, and 75 ppb dinoseb at 14, 62, and 110 h (n = 6 groups) after initiation of exposure. After 110 h, embryos were observed for normal development and hatching success, then either preserved in 10% formalin for growth analysis or flash frozen and extracted for HPLC-UV and (1)H NMR analysis. Dinoseb exposure at both concentrations resulted in significant declines in [ATP] and [PCr] at 110 h as measured by in vivo (31)P NMR (p fashion. Metabolic effects measured by in vivo (31)P NMR showed a significant increase in orthophosphate levels (P(i); p < 0.05), and significant decreases in [ATP], [PCr] and the PCr/P(i) ratio (p < 0.05). Metabolomics revealed a dose-response relationship between dinoseb and endogenous metabolite changes, with both dinoseb concentrations producing significantly different metabolic profiles from controls (p < 0.05). Metabolic changes included decreased concentrations of ATP, PCr, alanine and tyrosine, and increased concentrations of lactate with medaka embryotoxicity. This study demonstrated that medaka embryos respond to dinoseb with significant changes in metabolism, reduced growth and heart rates, and increased abnormal development and post-exposure mortality. All

  10. Performance of the WeNMR CS-Rosetta3 web server in CASD-NMR

    International Nuclear Information System (INIS)

    Schot, Gijs van der; Bonvin, Alexandre M. J. J.

    2015-01-01

    We present here the performance of the WeNMR CS-Rosetta3 web server in CASD-NMR, the critical assessment of automated structure determination by NMR. The CS-Rosetta server uses only chemical shifts for structure prediction, in combination, when available, with a post-scoring procedure based on unassigned NOE lists (Huang et al. in J Am Chem Soc 127:1665–1674, 2005b, doi: 10.1021/ja047109h 10.1021/ja047109h ). We compare the original submissions using a previous version of the server based on Rosetta version 2.6 with recalculated targets using the new R3FP fragment picker for fragment selection and implementing a new annotation of prediction reliability (van der Schot et al. in J Biomol NMR 57:27–35, 2013, doi: 10.1007/s10858-013-9762-6 10.1007/s10858-013-9762-6 ), both implemented in the CS-Rosetta3 WeNMR server. In this second round of CASD-NMR, the WeNMR CS-Rosetta server has demonstrated a much better performance than in the first round since only converged targets were submitted. Further, recalculation of all CASD-NMR targets using the new version of the server demonstrates that our new annotation of prediction quality is giving reliable results. Predictions annotated as weak are often found to provide useful models, but only for a fraction of the sequence, and should therefore only be used with caution

  11. A complete set of NMR chemical shifts and spin-spin coupling constants for L-Alanyl-L-Alanine zwitterion and analysis of its conformational behavior

    Czech Academy of Sciences Publication Activity Database

    Bouř, Petr; Buděšínský, Miloš; Špirko, Vladimír; Kapitán, Josef; Šebestík, Jaroslav; Sychrovský, Vladimír

    2005-01-01

    Roč. 127, - (2005), 17079-17089 ISSN 0002-7863 R&D Projects: GA AV ČR(CZ) IAA4055104; GA ČR(CZ) GA203/05/0388 Institutional research plan: CEZ:AV0Z40550506 Keywords : NMR * chemical shifts * coupling constants Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 7.419, year: 2005

  12. [superscript 1]H NMR Spectroscopy-Based Configurational Analysis of Mono- and Disaccharides and Detection of ß-Glucosidase Activity: An Undergraduate Biochemistry Laboratory

    Science.gov (United States)

    Periyannan, Gopal R.; Lawrence, Barbara A.; Egan, Annie E.

    2015-01-01

    A [superscript 1]H NMR spectroscopy-based laboratory experiment explores mono- and disaccharide structural chemistry, and the enzyme-substrate specificity of glycosidic bond cleavage by ß-glucosidase towards cellobiose (ß-linked gluco-disaccharide) and maltose (a-linked gluco-disaccharide). Structural differences between cellobiose, maltose, and…

  13. Molecular and Silica-Supported Molybdenum Alkyne Metathesis Catalysts: Influence of Electronics and Dynamics on Activity Revealed by Kinetics, Solid-State NMR, and Chemical Shift Analysis.

    Science.gov (United States)

    Estes, Deven P; Gordon, Christopher P; Fedorov, Alexey; Liao, Wei-Chih; Ehrhorn, Henrike; Bittner, Celine; Zier, Manuel Luca; Bockfeld, Dirk; Chan, Ka Wing; Eisenstein, Odile; Raynaud, Christophe; Tamm, Matthias; Copéret, Christophe

    2017-12-06

    Molybdenum-based molecular alkylidyne complexes of the type [MesC≡Mo{OC(CH 3 ) 3-x (CF 3 ) x } 3 ] (MoF 0 , x = 0; MoF 3 , x = 1; MoF 6 , x = 2; MoF 9 , x = 3; Mes = 2,4,6-trimethylphenyl) and their silica-supported analogues are prepared and characterized at the molecular level, in particular by solid-state NMR, and their alkyne metathesis catalytic activity is evaluated. The 13 C NMR chemical shift of the alkylidyne carbon increases with increasing number of fluorine atoms on the alkoxide ligands for both molecular and supported catalysts but with more shielded values for the supported complexes. The activity of these catalysts increases in the order MoF 0 catalysts coupled with DFT/ZORA calculations rationalize the NMR spectroscopic signatures and discernible activity trends at the frontier orbital level: (1) increasing the number of fluorine atoms lowers the energy of the π*(M≡C) orbital, explaining the more deshielded chemical shift values; it also leads to an increased electrophilicity and higher reactivity for catalysts up to MoF 6 , prior to a sharp decrease in reactivity for MoF 9 due to the formation of stable metallacyclobutadiene intermediates; (2) the silica-supported catalysts are less active than their molecular analogues because they are less electrophilic and dynamic, as revealed by their 13 C NMR chemical shift tensors.

  14. NMR spectroscopic study and DFT calculations of GIAO NMR ...

    African Journals Online (AJOL)

    1H, proton coupled and decoupled 13C, DEPT, HETCOR NMR spectra, the magnitude of one bond 1JCH coupling constants and 13C NMR spin-lattice relaxation time (T1) of 1,9-diaminononane (danon, C9H22N2) have been reported for the first time. 1H, 13C NMR chemical shifts and 1JCH coupling constants of danon ...

  15. Remote tuning of NMR probe circuits.

    Science.gov (United States)

    Kodibagkar, V D; Conradi, M S

    2000-05-01

    There are many circumstances in which the probe tuning adjustments cannot be located near the rf NMR coil. These may occur in high-temperature NMR, low-temperature NMR, and in the use of magnets with small diameter access bores. We address here circuitry for connecting a fixed-tuned probe circuit by a transmission line to a remotely located tuning network. In particular, the bandwidth over which the probe may be remotely tuned while keeping the losses in the transmission line acceptably low is considered. The results show that for all resonant circuit geometries (series, parallel, series-parallel), overcoupling of the line to the tuned circuit is key to obtaining a large tuning bandwidth. At equivalent extents of overcoupling, all resonant circuit geometries have nearly equal remote tuning bandwidths. Particularly for the case of low-loss transmission line, the tuning bandwidth can be many times the tuned circuit's bandwidth, f(o)/Q. Copyright 2000 Academic Press.

  16. Structural investigations on betacyanin pigments by LC NMR and 2D NMR spectroscopy.

    Science.gov (United States)

    Stintzing, Florian C; Conrad, Jürgen; Klaiber, Iris; Beifuss, Uwe; Carle, Reinhold

    2004-02-01

    Four betacyanin pigments were analysed by LC NMR and subjected to extensive NMR characterisation after isolation. Previously, low pH values were applied for NMR investigations of betalains resulting in rapid degradation of the purified substances thus preventing extensive NMR studies. Consequently, up to now only one single (13)C NMR spectrum of a betalain pigment, namely that of neobetanin (=14,15-dehydrobetanin), was available. Because of its sufficient stability under highly acidic conditions otherwise detrimental for betacyanins, this pigment remained an exemption. Since betalains are most stable in the pH range of 5-7, a new solvent system has been developed allowing improved data acquisition through improved pigment stability at near neutral pH. Thus, not only (1)H, but for the first time also partial (13)C data of betanin, isobetanin, phyllocactin and hylocerenin isolated from red-purple pitaya [Hylocereus polyrhizus (Weber) Britton & Rose, Cactaceae] could be indirectly obtained by gHSQC- and gHMQC-NMR experiments.

  17. Canalplasty: the technique and the analysis of its results

    NARCIS (Netherlands)

    van Spronsen, Erik; Ebbens, Fenna A.; Mirck, Peter G. B.; van Wettum, Cathelijne H. M.; van der Baan, Sieberen

    2013-01-01

    To describe the technique for canalplasty as performed in the Academic Medical Center, Amsterdam, the Netherlands and to present the results of this technique. Retrospective chart analysis. Charts of patients who underwent a canalplasty prodedure between 2001 and 2010 were reviewed for indication

  18. GRIZ: Visualization of finite element analysis results on unstructured grids

    International Nuclear Information System (INIS)

    Dovey, D.; Loomis, M.D.

    1994-01-01

    GRIZ is a general-purpose post-processing application that supports interactive visualization of finite element analysis results on three-dimensional unstructured grids. GRIZ includes direct-to-videodisc animation capabilities and is being used as a production tool for creating engineering animations

  19. Applications of NMR in biological metabolic research

    International Nuclear Information System (INIS)

    Nie Jiarui; Li Xiuqin; He Chunjian

    1989-01-01

    The nuclear magnetic resonance has become a powerful means of studying biological metabolism in non-invasive and non-destructive way. Being used to study the metabolic processes of living system in normal physiological conditions as well as in molecular level, the method is better than other conventional approaches. Using important parameters such as NMR-chemical shifts, longitudinal relaxation time and transverse relaxation time, it is possible to probe the metabolic processes as well as conformation, concentration, transportation and distribution of reacting and resulting substances. The NMR spectroscopy of 1 H, 31 P and 13 C nuclei has already been widely used in metabolic researches

  20. Programmable pulse series generator for NMR relaxometer

    International Nuclear Information System (INIS)

    Stolbunov, R.N.; Chichikov, S.A.; Lundin, A.G.

    2005-01-01

    Paper describes a pulse series generator for NMR relaxometer. The operation mode is set on the basis of the PC program by the PCI bus in the internal memory. The design is based on two Altera Company MAX7000S and Cyclone family microcircuits using the Qartus II 4.0 software. The basic parameters are as follows: pulse minimum length - 50 ns, time resolution - 10 ns, pulse maximum number - 1024, number of controlled output channels - 8. The designed device as a part of the NMR hardware-software system enables to record, to process and to store the experiment results in the form of electronic document [ru

  1. In depth analysis on the binding sites of adamantane derivatives in HCV (hepatitis C virus p7 channel based on the NMR structure.

    Directory of Open Access Journals (Sweden)

    Qi-Shi Du

    Full Text Available BACKGROUND: The recently solved solution structure of HCV (hepatitis C virus p7 ion channel provides a solid structure basis for drug design against HCV infection. In the p7 channel the ligand amantadine (or rimantadine was determined in a hydrophobic pocket. However the pharmocophore (-NH2 of the ligand was not assigned a specific binding site. RESULTS: The possible binding sites for amino group of adamantane derivatives is studied based on the NMR structure of p7 channel using QM calculation and molecular modeling. In the hydrophobic cavity and nearby three possible binding sites are proposed: His17, Phe20, and Trp21. The ligand binding energies at the three binding sites are studied using high level QM method CCSD(T/6-311+G(d,p and AutoDock calculations, and the interaction details are analyzed. The potential application of the binding sites for rational inhibitor design are discussed. CONCLUSIONS: Some useful viewpoints are concluded as follows. (1 The amino group (-NH2 of adamantane derivatives is protonated (-NH3+, and the positively charged cation may form cation-π interactions with aromatic amino acids. (2 The aromatic amino acids (His17, Phe20, and Trp21 are the possible binding sites for the protonated amino group (-NH3+ of adamantane derivatives, and the cation-π bond energies are 3 to 5 times stronger than the energies of common hydrogen bonds. (3 The higher inhibition potent of rimantadine than amantadine probably because of its higher pKa value (pKa = 10.40 and the higher positive charge in the amino group. The potential application of p7 channel structure for inhibitor design is discussed.

  2. NMR, HPLC-ESI-MS, and MALDI-TOF MS analysis of condensed tannins from Delonix regia (Bojer ex Hook.) Raf. and their bioactivities.

    Science.gov (United States)

    Chai, Wei-Ming; Shi, Yan; Feng, Hui-Ling; Qiu, Ling; Zhou, Hai-Chao; Deng, Zi-Wei; Yan, Chong-Ling; Chen, Qing-Xi

    2012-05-16

    The structures of the condensed tannins isolated from leaf, fruit, and stem bark of Delonix regia (Bojer ex Hook.) Raf. have been investigated with (13)C nuclear magnetic resonance ((13)C NMR) and high performance liquid chromatography electrospray ionization mass spectrometry (HPLC-ESI-MS) coupled with thiolysis and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) analyses. The results showed that these condensed tannins from D. regia possessed structural heterogeneity in monomer units and degree of polymerization. Propelargonidin (PP) and procyanidin (PC) were found in the leaf, fruit, and stem bark of D. regia, while prodelphinidin (PD) was found only in the leaves. The polymer chain lengths of condensed tannins from leaf and fruit organs were detected to be trimers to hexadecamers but from trimers to tridecamers for stem bark. B-type linkages were present in all these compounds. Condensed tannins from different parts of D. regia can be explored as tyrosinase inhibitors and food antioxidants because of their potent antityrosinase and antioxidant activities. The inhibitor concentration leading to 50% enzyme activity (IC(50)) was estimated to be 38 ± 1, 73 ± 2, and 54 ± 1.5 μg/mL for the condensed tannins of leaf, fruit, and stem bark. Condensed tannins extracted from stem bark exhibited the highest antioxidant activity; the DPPH scavenging activity (IC(50)) and the FRAP values were 90 ± 2 μg/mL and 5.42 ± 0.09 mmol AAE/g, respectively.

  3. Fast mapping of global protein folding states by multivariate NMR:

    DEFF Research Database (Denmark)

    Malmendal, Anders; Underhaug, Jarl; Otzen, Daniel

    2010-01-01

    that provides such an overview. GPS NMR exploits the unique ability of NMR to simultaneously record signals from individual hydrogen atoms in complex macromolecular systems and of multivariate analysis to describe spectral variations from these by a few variables for establishment of, and positioning in......, protein-folding state maps. The method is fast, sensitive, and robust, and it works without isotope-labelling. The unique capabilities of GPS NMR to identify different folding states and to compare different unfolding processes are demonstrated by mapping of the equilibrium folding space of bovine alpha......To obtain insight into the functions of proteins and their specific roles, it is important to establish efficient procedures for exploring the states that encapsulate their conformational space. Global Protein folding State mapping by multivariate NMR (GPS NMR) is a powerful high-throughput method...

  4. NMR studies of oriented molecules

    Energy Technology Data Exchange (ETDEWEB)

    Sinton, S.W.

    1981-11-01

    Deuterium and proton magnetic resonance are used in experiments on a number of compounds which either form liquid crystal mesophases themselves or are dissolved in a liquid crystal solvent. Proton multiple quantum NMR is used to simplify complicated spectra. The theory of nonselective multiple quantum NMR is briefly reviewed. Benzene dissolved in a liquid crystal are used to demonstrate several outcomes of the theory. Experimental studies include proton and deuterium single quantum (..delta..M = +-1) and proton multiple quantum spectra of several molecules which contain the biphenyl moiety. 4-Cyano-4'-n-pentyl-d/sub 11/-biphenyl (5CB-d/sub 11/) is studied as a pure compound in the nematic phase. The obtained chain order parameters and dipolar couplings agree closely with previous results. Models for the effective symmetry of the biphenyl group in 5CB-d/sub 11/ are tested against the experimental spectra. The dihedral angle, defined by the planes containing the rings of the biphenyl group, is found to be 30 +- 2/sup 0/ for 5DB-d/sub 11/. Experiments are also described for 4,4'-d/sub 2/-biphenyl, 4,4' - dibromo-biphenyl, and unsubstituted biphenyl.

  5. NMR imaging of the spine

    Energy Technology Data Exchange (ETDEWEB)

    Han, J.S. (Case Western Reserve Univ. School of Medicine, Cleveland, OH); Kaufman, B.; El Yousef, S.J.; Benson, J.E.; Bonstelle, C.T.; Alfidi, R.J.; Haaga, J.R.; Yeung, H.; Huss, R.G.

    1983-12-01

    The usefulness of nuclear magnetic resonance (NMR) images in the evaluation of spinal disorders below the craniocervical junction was studied. Six normal subjects and 41 patients with various spinal abnormalities were examined. NMR proved capable of demonstrating important normal and pathologic anatomic structures; it was useful in the evaluation of syringohydromyelia and cystic spinal cord tumors, and the bright signal intensity of lipoma was quite impressive. In the evaluation of herniated disk, NMR images offered a new perspective by visualizing abnormal degradation of the signal intensity of the nucleus pulposus itself. NMR images were least valuable in the evaluation of spondylosis and spinal stenosis. Although NMR imaging of the spine is still in a very early developmental stage, the absence of both ionizing radiation and risks associated with contrast material makes it especially attractive as a new diagnostic method. This limited experience with currently available equipment suggests that, with technical refinement, the efficacy of NMR of the spine will increase.

  6. Use of safety analysis results to support process operation

    International Nuclear Information System (INIS)

    Karvonen, I.; Heino, P.

    1990-01-01

    Safety and risk analysis carried out during the design phase of a process plant produces useful knowledge about the behavior and the disturbances of the system. This knowledge, however, often remains to the designer though it would be of benefit to the operators and supervisors of the process plant, too. In Technical Research Centre of Finland a project has been started to plan and construct a prototype of an information system to make use of the analysis knowledge during the operation phase. The project belongs to a Nordic KRM project (Knowledge Based Risk Management System). The information system is planned to base on safety and risk analysis carried out during the design phase and completed with operational experience. The safety analysis includes knowledge about potential disturbances, their causes and consequences in the form of Hazard and Operability Study, faut trees and/or event trees. During the operation disturbances can however, occur, which are not included in the safety analysis, or the causes or consequences of which have been incompletely identified. Thus the information system must also have an interface for the documentation of the operational knowledge missing from the analysis results. The main tasks off the system when supporting the management of a disturbance are to identify it (or the most important of the coexistent ones) from the stored knowledge and to present it in a proper form (for example as a deviation graph). The information system may also be used to transfer knowledge from one shift to another and to train process personnel

  7. Representation of analysis results involving aleatory and epistemic uncertainty.

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, Jay Dean (ProStat, Mesa, AZ); Helton, Jon Craig (Arizona State University, Tempe, AZ); Oberkampf, William Louis; Sallaberry, Cedric J.

    2008-08-01

    Procedures are described for the representation of results in analyses that involve both aleatory uncertainty and epistemic uncertainty, with aleatory uncertainty deriving from an inherent randomness in the behavior of the system under study and epistemic uncertainty deriving from a lack of knowledge about the appropriate values to use for quantities that are assumed to have fixed but poorly known values in the context of a specific study. Aleatory uncertainty is usually represented with probability and leads to cumulative distribution functions (CDFs) or complementary cumulative distribution functions (CCDFs) for analysis results of interest. Several mathematical structures are available for the representation of epistemic uncertainty, including interval analysis, possibility theory, evidence theory and probability theory. In the presence of epistemic uncertainty, there is not a single CDF or CCDF for a given analysis result. Rather, there is a family of CDFs and a corresponding family of CCDFs that derive from epistemic uncertainty and have an uncertainty structure that derives from the particular uncertainty structure (i.e., interval analysis, possibility theory, evidence theory, probability theory) used to represent epistemic uncertainty. Graphical formats for the representation of epistemic uncertainty in families of CDFs and CCDFs are investigated and presented for the indicated characterizations of epistemic uncertainty.

  8. Interactive color display of 3-D engineering analysis results

    Science.gov (United States)

    Abel, John F.; Ingraffea, Anthony R.; Greenberg, Donald P.

    1987-01-01

    A general approach to three-dimensional postprocessing of engineering analyses is presented. The approach is versatile and may handle the results from a wide range of engineering analysis methods which involve the discretization of continua. To facilitate the understanding of complex three-dimensional numerical models, advanced interactive color postprocessing techniques are introduced. Finite element, finite difference, and boundary element models are evaluated with the prototype postprocessor. The existing color graphics program (POSTPRO3D) was ported to a high-resolution device. Interactive graphic tools were implemented to facilitate qualitative mesh evaluation from a single analysis. A postprocessing environment was design for workstation technology.

  9. Discrimination of Basal Cell Carcinoma from Normal Skin Tissue Using High-Resolution Magic Angle Spinning 1H NMR Spectroscopy.

    Science.gov (United States)

    Mun, Je-Ho; Lee, Heonho; Yoon, Dahye; Kim, Byung-Soo; Kim, Moon-Bum; Kim, Shukmann

    2016-01-01

    High-resolution magic angle spinning nuclear magnetic resonance (HR-MAS NMR) spectroscopy is a useful tool for investigating the metabolism of various cancers. Basal cell carcinoma (BCC) is the most common skin cancer. However, to our knowledge, data on metabolic profiling of BCC have not been reported in the literature. The objective of the present study was to investigate the metabolic profiling of cutaneous BCC using HR-MAS (1)H NMR spectroscopy. HR-MAS (1)H NMR spectroscopy was used to analyze the metabolite profile and metabolite intensity of histopathologically confirmed BCC tissues and normal skin tissue (NST) samples. The metabolic intensity normalized to the total spectral intensities in BCC and NST was compared, and multivariate analysis was performed with orthogonal partial least-squares discriminant analysis (OPLS-DA). P values analysis revealed 9 metabolites that showed statistically significant difference between BCC and NST. In multivariate analysis, the OPLS-DA models built with the HR-MAS NMR metabolic profiles revealed a clear separation of BCC from NST. The receiver operating characteristic curve generated from the results revealed an excellent discrimination of BCC from NST with an area under the curve (AUC) value of 0.961. The present study demonstrated that the metabolite profile and metabolite intensity differ between BCC and NST, and that HR-MAS (1)H NMR spectroscopy can be a valuable tool in the diagnosis of BCC.

  10. Spectroscopic data of Labdane Diterpenes: a theoretical analysis via NMR and DFT; Dados espectroscópicos de diterpenos Labdânicos: uma análise teórica via RMN e DFT

    Energy Technology Data Exchange (ETDEWEB)

    Souza, Fabrine S. de; Silva, Silvana de O.; Alves, Cláudio N.; Guilhon, Giselle M.S.P. [Universidade Federal do Pará (UFPA), Belém, PA (Brazil). Instituto de Ciências Exatas e Naturais; Faria, Lênio J.G. de; Brasil, Davi do S.B., E-mail: davibb@ufpa.br [Universidade Federal do Pará, Belém, PA (Brazil). Instituto de Tecnologia; Muller, Adolfo H. [Centro Universitário do Estado do Pará, Belém, PA (Brazil)

    2015-06-15

    Labdane diterpenes exhibit important bioactivities such as cardiovascular effects in rats as well as effects in the treatment of autoimmune diseases and Alzheimer syndrome. Recently, the labdane diterpenes ent-13-epi-manoil oxide, ribenone and ribenol were isolated from Croton palanostigma. The computational method DFT/B3LYP/cc-pVDZ was used to optimize the structures of these diterpenes and to calculate infrared data. Chemical shifts (δ{sub H} and δ{sub C}) of the minimum energy structures (local minimum) were calculated and compared with the experimental data. Comparison of the NMR data by simple linear regression (SLR) showed satisfactory statistical results with a correlation coefficient (R{sup 2} ) and predictive ability (Q{sup 2}) of over 98%. The predicted NMR data were used to confirm the δ{sub H} values that have not been published. (author)

  11. Analysis of oil content and oil quality in oilseeds by low-field NMR; Analise do teor e da qualidade dos lipideos presentes em sementes de oleaginosas por RMN de baixo campo

    Energy Technology Data Exchange (ETDEWEB)

    Constantino, Andre F.; Lacerda Junior, Valdemar; Santos, Reginaldo B. dos; Greco, Sandro J.; Silva, Renzo C.; Neto, Alvaro C.; Barbosa, Lucio L.; Castro, Eustaquio V.R. de [Universidade Federal do Espirito Santo (UFES), Vitoria, ES (Brazil). Departamento de Quimica; Freitas, Jair C.C. [Universidade Federal do Espirito Santo (UFES), Vitoria, ES (Brazil). Departamento de Fisica

    2014-07-01

    To choose among the variety of oleaginous plants for biodiesel production, the oil content of several matrices was determined through different low-field {sup 1}H nuclear magnetic resonance (NMR) experiments with varied pulse sequences, namely single-pulse, spin-echo, CPMG, and CWFP. The experiments that involved the first three sequences showed high correlation with each other and with the solvent extraction method. The quality of the vegetable oils was also evaluated on the basis of the existing correlation between the T{sub 2} values of the oils and their properties, such as viscosity, iodine index, and cetane index. These analyses were performed using HCA and PCA chemometric tools. The results were sufficiently significant to allow separation of the oleaginous matrices according to their quality. Thus, the low-field {sup 1}H NMR technique was confirmed as an important tool to aid in the selection of oleaginous matrices for biodiesel production. (author)

  12. High-Sensitivity Rheo-NMR Spectroscopy for Protein Studies.

    Science.gov (United States)

    Morimoto, Daichi; Walinda, Erik; Iwakawa, Naoto; Nishizawa, Mayu; Kawata, Yasushi; Yamamoto, Akihiko; Shirakawa, Masahiro; Scheler, Ulrich; Sugase, Kenji

    2017-07-18

    Shear stress can induce structural deformation of proteins, which might result in aggregate formation. Rheo-NMR spectroscopy has the potential to monitor structural changes in proteins under shear stress at the atomic level; however, existing Rheo-NMR methodologies have insufficient sensitivity to probe protein structure and dynamics. Here we present a simple and versatile approach to Rheo-NMR, which maximizes sensitivity by using a spectrometer equipped with a cryogenic probe. As a result, the sensitivity of the instrument ranks highest among the Rheo-NMR spectrometers reported so far. We demonstrate that the newly developed Rheo-NMR instrument can acquire high-quality relaxation data for a protein under shear stress and can trace structural changes in a protein during fibril formation in real time. The described approach will facilitate rheological studies on protein structural deformation, thereby aiding a physical understanding of shear-induced amyloid fibril formation.

  13. Structural, vibrational, NMR, quantum chemical, DNA binding and ...

    Indian Academy of Sciences (India)

    -one oxime (HL¹) and 3-(pyridin-2-ylmethylimino)-pentan-2-one oxime (HL²) have been synthesized and characterized by elemental analysis, IR and NMR techniques. The conformational behavior was investigated using the density functional ...

  14. Bioelectrical impedance analysis for bovine milk: Preliminary results

    Science.gov (United States)

    Bertemes-Filho, P.; Valicheski, R.; Pereira, R. M.; Paterno, A. S.

    2010-04-01

    This work reports the investigation and analysis of bovine milk quality by using biological impedance measurements using electrical impedance spectroscopy (EIS). The samples were distinguished by a first chemical analysis using Fourier transform midinfrared spectroscopy (FTIR) and flow citometry. A set of milk samples (100ml each) obtained from 17 different cows in lactation with and without mastitis were analyzed with the proposed technique using EIS. The samples were adulterated by adding distilled water and hydrogen peroxide in a controlled manner. FTIR spectroscopy and flow cytometry were performed, and impedance measurements were made in a frequency range from 500Hz up to 1MHz with an implemented EIS system. The system's phase shift was compensated by measuring saline solutions. It was possible to show that the results obtained with the Bioelectrical Impedance Analysis (BIA) technique may detect changes in the milk caused by mastitis and the presence of water and hydrogen peroxide in the bovine milk.

  15. New insights into glycopeptide antibiotic binding to cell wall precursors using SPR and NMR spectroscopy.

    Science.gov (United States)

    Treviño, Juan; Bayón, Carlos; Ardá, Ana; Marinelli, Flavia; Gandolfi, Raffaella; Molinari, Francesco; Jimenez-Barbero, Jesús; Hernáiz, María J

    2014-06-10

    Glycopeptide antibiotics, such as vancomycin and teicoplanin, are used to treat life-threatening infections caused by m