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Sample records for 1h-nmr composite signal

  1. Pore size distribution calculation from 1H NMR signal and N2 adsorption-desorption techniques

    NASA Astrophysics Data System (ADS)

    Hassan, Jamal

    2012-09-01

    The pore size distribution (PSD) of nano-material MCM-41 is determined using two different approaches: N2 adsorption-desorption and 1H NMR signal of water confined in silica nano-pores of MCM-41. The first approach is based on the recently modified Kelvin equation [J.V. Rocha, D. Barrera, K. Sapag, Top. Catal. 54(2011) 121-134] which deals with the known underestimation in pore size distribution for the mesoporous materials such as MCM-41 by introducing a correction factor to the classical Kelvin equation. The second method employs the Gibbs-Thompson equation, using NMR, for melting point depression of liquid in confined geometries. The result shows that both approaches give similar pore size distribution to some extent, and also the NMR technique can be considered as an alternative direct method to obtain quantitative results especially for mesoporous materials. The pore diameter estimated for the nano-material used in this study was about 35 and 38 Å for the modified Kelvin and NMR methods respectively. A comparison between these methods and the classical Kelvin equation is also presented.

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

    PubMed Central

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

    2016-01-01

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

  3. Revealing Aquatic Dissolved Organic Matter Composition using Direct 1H NMR Spectroscopy

    NASA Astrophysics Data System (ADS)

    Burns, D. C.; Gueguen, C.

    2009-05-01

    Dissolved organic matter (DOM) is ubiquitous in all aquatic ecosystems, and comprises a variety of chemically heterogeneous molecular structures and functional groups. DOM is often considered to be a major ligand for metals in most natural waters. However DOM reactivity is thought to be strongly dependent on its chemical structure. The purpose of this study is to evaluate the variability in molecular composition of aquatic DOM from different sources. Quantitative proton NMR spectra were obtained without any preconcentration using water suppression techniques. The reproducibility on the determination of aromatic and aliphatic proton was better than 3%. The structural information of DOM from northern rivers was compared to IHSS humic substances.

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

    PubMed

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

    2001-10-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2001-10-01

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

  6. Mapping hypoxia-induced bioenergetic rearrangements and metabolic signaling by 18O-assisted 31P NMR and 1H NMR spectroscopy.

    PubMed

    Pucar, Darko; Dzeja, Petras P; Bast, Peter; Gumina, Richard J; Drahl, Carmen; Lim, Lynette; Juranic, Nenad; Macura, Slobodan; Terzic, Andre

    2004-01-01

    Brief hypoxia or ischemia perturbs energy metabolism inducing paradoxically a stress-tolerant state, yet metabolic signals that trigger cytoprotection remain poorly understood. To evaluate bioenergetic rearrangements, control and hypoxic hearts were analyzed with 18O-assisted 31P NMR and 1H NMR spectroscopy. The 18O-induced isotope shift in the 31P NMR spectrum of CrP, betaADP and betaATP was used to quantify phosphotransfer fluxes through creatine kinase and adenylate kinase. This analysis was supplemented with determination of energetically relevant metabolites in the phosphomonoester (PME) region of 31P NMR spectra, and in both aromatic and aliphatic regions of 1H NMR spectra. In control conditions, creatine kinase was the major phosphotransfer pathway processing high-energy phosphoryls between sites of ATP consumption and ATP production. In hypoxia, creatine kinase flux was dramatically reduced with a compensatory increase in adenylate kinase flux, which supported heart energetics by regenerating and transferring beta- and gamma-phosphoryls of ATP. Activation of adenylate kinase led to a build-up of AMP, IMP and adenosine, molecules involved in cardioprotective signaling. 31P and 1H NMR spectral analysis further revealed NADH and H+ scavenging by alpha-glycerophosphate dehydrogenase (alphaGPDH) and lactate dehydrogenase contributing to maintained glycolysis under hypoxia. Hypoxia-induced accumulation of alpha-glycerophosphate and nucleoside 5'-monophosphates, through alphaGPDH and adenylate kinase reactions, respectively, was mapped within the increased PME signal in the 31P NMR spectrum. Thus, 18O-assisted 31P NMR combined with 1H NMR provide a powerful approach in capturing rearrangements in cardiac bioenergetics, and associated metabolic signaling that underlie the cardiac adaptive response to stress. PMID:14977188

  7. Independent component analysis (ICA) algorithms for improved spectral deconvolution of overlapped signals in 1H NMR analysis: application to foods and related products.

    PubMed

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

    2014-05-01

    The major challenge facing NMR spectroscopic mixture analysis is the overlapping of signals and the arising impossibility to easily recover the structures for identification of the individual components and to integrate separated signals for quantification. In this paper, various independent component analysis (ICA) algorithms [mutual information least dependent component analysis (MILCA); stochastic non-negative ICA (SNICA); joint approximate diagonalization of eigenmatrices (JADE); and robust, accurate, direct ICA algorithm (RADICAL)] as well as deconvolution methods [simple-to-use-interactive self-modeling mixture analysis (SIMPLISMA) and multivariate curve resolution-alternating least squares (MCR-ALS)] are applied for simultaneous (1)H NMR spectroscopic determination of organic substances in complex mixtures. Among others, we studied constituents of the following matrices: honey, soft drinks, and liquids used in electronic cigarettes. Good quality spectral resolution of up to eight-component mixtures was achieved (correlation coefficients between resolved and experimental spectra were not less than 0.90). In general, the relative errors in the recovered concentrations were below 12%. SIMPLISMA and MILCA algorithms were found to be preferable for NMR spectra deconvolution and showed similar performance. The proposed method was used for analysis of authentic samples. The resolved ICA concentrations match well with the results of reference gas chromatography-mass spectrometry as well as the MCR-ALS algorithm used for comparison. ICA deconvolution considerably improves the application range of direct NMR spectroscopy for analysis of complex mixtures. PMID:24604756

  8. 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

    NASA Astrophysics Data System (ADS)

    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.

  9. Changes in the Amino Acid Composition of Bogue (Boops boops) Fish during Storage at Different Temperatures by 1H-NMR Spectroscopy

    PubMed Central

    Ciampa, Alessandra; Picone, Gianfranco; Laghi, Luca; Nikzad, Homa; Capozzi, Francesco

    2012-01-01

    Nuclear magnetic resonance spectroscopy was employed to obtain information about the changes occurring in Bogue (Boops boops) fish during storage. For this purpose, 1H-NMR spectra were recorded at 600 MHz on trichloroacetic acid extracts of fish flesh stored over a 15 days period both at 4 °C and on ice. Such spectra allowed the identification and quantification of amino acids, together with the main organic acids and alcohols. The concentration of acidic and basic free amino acids was generally found to increase and decrease during storage, respectively. These concentration changes were slow during the first days, as a consequence of protein autolysis, and at higher rates afterward, resulting from microbial development. Two of the amino acids that showed the greatest concentration change were alanine and glycine, known to have a key role in determining the individual taste of different fish species. The concentration of serine decreased during storage, as highlighted in the literature for frozen fish samples. Differences in the amino acids concentration trends were found to be related to the different storage temperatures from day 4 onwards. PMID:22822452

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

    PubMed

    Jacob, Daniel; Deborde, Catherine; Moing, Annick

    2013-06-01

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

  11. Comparative study for separation of atmospheric humic-like substance (HULIS) by ENVI-18, HLB, XAD-8 and DEAE sorbents: elemental composition, FT-IR, 1H NMR and off-line thermochemolysis with tetramethylammonium hydroxide (TMAH).

    PubMed

    Fan, Xingjun; Song, Jianzhong; Peng, Ping'an

    2013-11-01

    Humic-like substances (HULIS) are significant constituents of aerosols, and the isolation and characterization of HULIS by solid-phase extraction methods are dependent on the sorbents used. In this study, we used the following five methods: ENVI-18, HLB-M, HLB-N, XAD-8 and DEAE, to isolate atmospheric HULIS at an urban site. Then we conducted a comparative investigation of the HULIS chemical characteristics by means of elemental analysis, Fourier transform infrared spectroscopy, (1)H nuclear magnetic resonance spectroscopy and off-line thermochemolysis with tetramethylammonium hydroxide. The results indicate that HULIS isolated using different methods show many similarities in chemical composition and structure. Some differences were however also observed between the five isolated HULIS: HULISHLB-M contains a relatively high content of OCH group, compared to HULISENVI-18 and HULISXAD-8; HULISXAD-8 contains a relatively high content of hydrophobic and aromatic components, compared to HULISENVI-18 and HULISHLB-M; HULISDEAE contains the highest content of aromatic functional groups, as inferred by (1)H NMR spectra, but a great amount of salts generally present in the HULISDEAE and thereby limited the choices for characterizing the materials (i.e., elemental analysis and TMAH thermochemolysis); HULISHLB-N has relatively high levels of H and N, a high N/C atomic ratio, and includes N-containing functional groups, which suggests that it has been altered by 2% ammonia introduced in the eluents. In summary, we found that ENVI-18, HLB-M, and XAD-8 are preferable methods for isolation and characterization of HULIS in atmospheric aerosols. These results also suggest that caution is required when applying DEAE and HLB-N isolating methods for characterizing atmospheric HULIS. PMID:23773442

  12. Proton Fingerprints Portray Molecular Structures: Enhanced Description of the 1H NMR Spectra of Small Molecules

    PubMed Central

    Napolitano, José G.; Lankin, David C.; McAlpine, James B.; Niemitz, Matthias; Korhonen, Samuli-Petrus; Chen, Shao-Nong; Pauli, Guido F.

    2013-01-01

    The characteristic signals observed in NMR spectra encode essential information on the structure of small molecules. However, extracting all of this information from complex signal patterns is not trivial. This report demonstrates how computer-aided spectral analysis enables the complete interpretation of 1D 1H NMR data. The effectiveness of this approach is illustrated with a set of organic molecules, for which replicas of their 1H NMR spectra were generated. The potential impact of this methodology on organic chemistry research is discussed. PMID:24007197

  13. 1H NMR detection of small molecules in human urine with a deep cavitand synthetic receptor.

    PubMed

    Ryan, Daniel A; Rebek, Julius

    2013-02-21

    A water-soluble deep cavitand recognized alkylammonium salts, including the drug amantadine hydrochloride, in spiked samples of human urine. The signals of the guests are detected by (1)H NMR upfield of 0 ppm and so occur in a spectroscopic window that is outside of the normal region and distinct from the signals of the biofluid components. PMID:23304698

  14. Metabolomic differentiation of Cannabis sativa cultivars using 1H NMR spectroscopy and principal component analysis.

    PubMed

    Choi, Young Hae; Kim, Hye Kyong; Hazekamp, Arno; Erkelens, Cornelis; Lefeber, Alfons W M; Verpoorte, Robert

    2004-06-01

    The metabolomic analysis of 12 Cannabis sativa cultivars was carried out by 1H NMR spectroscopy and multivariate analysis techniques. Principal component analysis (PCA) of the 1H NMR spectra showed a clear discrimination between those samples by principal component 1 (PC1) and principal component 3 (PC3) in cannabinoid fraction. The loading plot of PC value obtained from all 1)H NMR signals shows that Delta9-tetrahydrocannabinolic acid (THCA) and cannabidiolic acid (CBDA) are important metabolites to differentiate the cultivars from each other. The discrimination of the cultivars could also be obtained from a water extract containing carbohydrates and amino acids. The level of sucrose, glucose, asparagine, and glutamic acid are found to be major discriminating metabolites of these cultivars. This method allows an efficient differentiation between cannabis cultivars without any prepurification steps. PMID:15217272

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

    NASA Astrophysics Data System (ADS)

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

    2014-10-01

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

  16. 1H NMR metabolomics study of age profiling in children

    PubMed Central

    Gu, Haiwei; Pan, Zhengzheng; Xi, Bowei; Hainline, Bryan E.; Shanaiah, Narasimhamurthy; Asiago, Vincent; Nagana Gowda, G. A.; Raftery, Daniel

    2014-01-01

    Metabolic profiling of urine provides a fingerprint of personalized endogenous metabolite markers that correlate to a number of factors such as gender, disease, diet, toxicity, medication, and age. It is important to study these factors individually, if possible to unravel their unique contributions. In this study, age-related metabolic changes in children of age 12 years and below were analyzed by 1H NMR spectroscopy of urine. The effect of age on the urinary metabolite profile was observed as a distinct age-dependent clustering even from the unsupervised principal component analysis. Further analysis, using partial least squares with orthogonal signal correction regression with respect to age, resulted in the identification of an age-related metabolic profile. Metabolites that correlated with age included creatinine, creatine, glycine, betaine/TMAO, citrate, succinate, and acetone. Although creatinine increased with age, all the other metabolites decreased. These results may be potentially useful in assessing the biological age (as opposed to chronological) of young humans as well as in providing a deeper understanding of the confounding factors in the application of metabolomics. PMID:19441074

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

    NASA Astrophysics Data System (ADS)

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

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

  18. Applications of 1H-NMR to Biodiesel Research

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  19. NMRmix: A Tool for the Optimization of Compound Mixtures in 1D (1)H NMR Ligand Affinity Screens.

    PubMed

    Stark, Jaime L; Eghbalnia, Hamid R; Lee, Woonghee; Westler, William M; Markley, John L

    2016-04-01

    NMR ligand affinity screening is a powerful technique that is routinely used in drug discovery or functional genomics to directly detect protein-ligand binding events. Binding events can be identified by monitoring differences in the 1D (1)H NMR spectrum of a compound with and without protein. Although a single NMR spectrum can be collected within a short period (2-10 min per sample), one-by-one screening of a protein against a library of hundreds or thousands of compounds requires a large amount of spectrometer time and a large quantity of protein. Therefore, compounds are usually evaluated in mixtures ranging in size from 3 to 20 compounds to improve the efficiency of these screens in both time and material. Ideally, the NMR signals from individual compounds in the mixture should not overlap so that spectral changes can be associated with a particular compound. We have developed a software tool, NMRmix, to assist in creating ideal mixtures from a large panel of compounds with known chemical shifts. Input to NMRmix consists of an (1)H NMR peak list for each compound, a user-defined overlap threshold, and additional user-defined parameters if default settings are not used. NMRmix utilizes a simulated annealing algorithm to optimize the composition of the mixtures to minimize spectral peak overlaps so that each compound in the mixture is represented by a maximum number of nonoverlapping chemical shifts. A built-in graphical user interface simplifies data import and visual evaluation of the results. PMID:26965640

  20. NMRmix: A Tool for the Optimization of Compound Mixtures in 1D 1H NMR Ligand Affinity Screens

    PubMed Central

    2016-01-01

    NMR ligand affinity screening is a powerful technique that is routinely used in drug discovery or functional genomics to directly detect protein–ligand binding events. Binding events can be identified by monitoring differences in the 1D 1H NMR spectrum of a compound with and without protein. Although a single NMR spectrum can be collected within a short period (2—10 min per sample), one-by-one screening of a protein against a library of hundreds or thousands of compounds requires a large amount of spectrometer time and a large quantity of protein. Therefore, compounds are usually evaluated in mixtures ranging in size from 3 to 20 compounds to improve the efficiency of these screens in both time and material. Ideally, the NMR signals from individual compounds in the mixture should not overlap so that spectral changes can be associated with a particular compound. We have developed a software tool, NMRmix, to assist in creating ideal mixtures from a large panel of compounds with known chemical shifts. Input to NMRmix consists of an 1H NMR peak list for each compound, a user-defined overlap threshold, and additional user-defined parameters if default settings are not used. NMRmix utilizes a simulated annealing algorithm to optimize the composition of the mixtures to minimize spectral peak overlaps so that each compound in the mixture is represented by a maximum number of nonoverlapping chemical shifts. A built-in graphical user interface simplifies data import and visual evaluation of the results. PMID:26965640

  1. Laundering and Deinking Applications of 1H NMR Imaging

    NASA Astrophysics Data System (ADS)

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

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

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

    PubMed

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

    2015-09-01

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

  3. A 1H NMR assay for measuring the photostationary States of photoswitchable ligands.

    PubMed

    Banghart, Matthew R; Trauner, Dirk

    2013-01-01

    Incorporation of photoisomerizable chromophores into small molecule ligands represents a general approach for reversibly controlling protein function with light. Illumination at different wavelengths produces photostationary states (PSSs) consisting of different ratios of photoisomers. Thus optimal implementation of photoswitchable ligands requires knowledge of their wavelength sensitivity. Using an azobenzene-based ion channel blocker as an example, this protocol describes a (1)H NMR assay that can be used to precisely determine the isomeric content of photostationary states (PSSs) as a function of illumination wavelength. Samples of the photoswitchable ligand are dissolved in deuterated water and analyzed by UV/VIS spectroscopy to identify the range of illumination wavelengths that produce PSSs. The PSSs produced by these wavelengths are quantified using (1)H NMR spectroscopy under continuous irradiation through a monochromator-coupled fiber-optic cable. Because aromatic protons of azobenzene trans and cis isomers exhibit sufficiently different chemical shifts, their relative abundances at each PSS can be readily determined by peak integration. Constant illumination during spectrum acquisition is essential to accurately determine PSSs from molecules that thermally relax on the timescale of minutes or faster. This general protocol can be readily applied to any photoswitch that exhibits distinct (1)H NMR signals in each photoisomeric state. PMID:23494375

  4. Dynamic 1H NMR Studies of Schiff Base Derivatives

    NASA Astrophysics Data System (ADS)

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

    2016-01-01

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

  5. The 1H NMR Profile of Healthy Dog Cerebrospinal Fluid

    PubMed Central

    Musteata, Mihai; Nicolescu, Alina; Solcan, Gheorghe; Deleanu, Calin

    2013-01-01

    The availability of data for reference values in cerebrospinal fluid for healthy humans is limited due to obvious practical and ethical issues. The variability of reported values for metabolites in human cerebrospinal fluid is quite large. Dogs present great similarities with humans, including in cases of central nervous system pathologies. The paper presents the first study on healthy dog cerebrospinal fluid metabolomic profile using 1H NMR spectroscopy. A number of 13 metabolites have been identified and quantified from cerebrospinal fluid collected from a group of 10 mix breed healthy dogs. The biological variability as resulting from the relative standard deviation of the physiological concentrations of the identified metabolites had a mean of 18.20% (range between 9.3% and 44.8%). The reported concentrations for metabolites may be used as normal reference values. The homogeneity of the obtained results and the low biologic variability show that the 1H NMR analysis of the dog’s cerebrospinal fluid is reliable in designing and interpreting clinical and therapeutic trials in dogs with central nervous system pathologies. PMID:24376499

  6. 1H NMR structure of the heme pocket of HNO-myoglobin.

    PubMed

    Sulc, Filip; Fleischer, Everly; Farmer, Patrick J; Ma, Dejian; La Mar, Gerd N

    2003-02-01

    The unique (1)H NMR signal of nitrosyl hydride at 14.8 ppm is used to obtain a solution structure of the distal pocket of Mb-HNO, a rare nitroxyl adduct with a half-life of several months at room temperature. (1)H NMR, NOESY and TOCSY data were obtained under identical experimental conditions on solutions of the diamagnetic HNO and CO complexes of equine Mb, allowing direct comparison of NMR data to a crystallographically characterized structure. Twenty NOEs between the nitrosyl hydride and protein and heme-based signals were observed. The HNO orientation obtained by modeling the experimental (1)H NMR NOESY data yielded an orientation of ca. -104 degrees referenced to the N-Fe-N vector between alpha and beta mesoprotons. An essentially identical orientation was obtained by simple energy minimization of the HNO adduct using ESFF potentials, suggesting steric control of the orientation. Differences in chemical shifts are seen for protons on residues Phe43(CD1) and Val68(E11), but both exhibit virtually identical NOESY contacts to other residues, and thus are attributed to small movements of ca. 0.1 A within the strong ring current. The most significant differences are seen in the NOESY peak intensities and chemical shifts for the ring non-labile protons of the distal His64(E7). The orientation of the His64(E7) in Mb-HNO was analyzed on the basis of the NOESY cross-peak changes and chemical shift changes, predicting a ca. 20 degrees rotation about the beta-gamma bond. The deduced HNO and His64(E7) orientations result in geometry where the His64(E7) ring can serve as the donor for a significant H-bond to the oxygen atom of the bound HNO. PMID:12589571

  7. 1H NMR studies of aerosol-OT reverse micelles with alkali and magnesium counterions: preparation and analysis of MAOTs.

    PubMed

    Stahla, Michelle L; Baruah, Bharat; James, Dustin M; Johnson, Michael D; Levinger, Nancy E; Crans, Debbie C

    2008-06-17

    Simple procedures and characterization of a series of well-defined precursors are described for preparation of a unique microenvironment in nanoreactors, reverse micelles. The Na(+), K(+), Rb(+), Cs(+), and Mg(2+) surfactants were prepared using liquid-liquid ion exchange using chloride and nitrate salts. The surfactants were characterized using (1)H NMR spectroscopy and a variety of other techniques. (1)H NMR spectroscopy was found to be a sensitive probe for characterization of the size of the nanoreactor as well as its water content. (1)H NMR spectra can be used for detailed characterization of reactions in confined environments when counterion effects are likely to be important. (1)H NMR spectroscopy revealed two separate peaks corresponding to water in Mg(AOT)2 samples; one peak arises from water coordinated to the Mg(2+) ion while the other peak arises from bulk water. The two water signals arise directly from the slow exchange of the water coordinated to Mg(2+) in these microemulsions with water in the water pool, and provide an opportunity to study hydration of Mg(2+). This work thus extends the potential use of MAOT microemulsions for applications such as in green chemistry. PMID:18484757

  8. An optimized and validated (1)H NMR method for the quantification of α-pinene in essentials oils.

    PubMed

    Cerceau, Cristiane I; Barbosa, Luiz C A; Filomeno, Claudinei A; Alvarenga, Elson S; Demuner, Antônio J; Fidencio, Paulo H

    2016-04-01

    The authenticity and composition of commercial essential oils requires strict quality control. Due to the importance of α-pinene containing essential oils, a rapid and efficient method for quantification of this terpene in oils of eucalyptus, pink pepper and turpentine using (1)H NMR was developed and validated. All evaluated parameters (selectivity, linearity, accuracy/precision, repeatability, robustness, stability of analyte and internal standard in solutions) showed satisfactory results. The limit of detection (LOD) and limit of quantification (LOQ) were 0.1 and 2.5mg respectively. These values indicated that α-pinene was detected in 35 mg samples containing at least 0.3% of this compound. In addition, a minimum of 8% of α-pinene in the sample was required for quantification. Furthermore, the standard deviations found in the (1)H NMR methodology were less than 1% and were lower than those obtained by gas chromatographic analysis. Statistical tests have shown that the results obtained by (1)H NMR methodology are similar to those obtained by GC-FID technique using external and internal standardization and normalization within 95% confidence. R&R values lower than 10% have shown that all the methods are appropriate and the (1)H NMR method is suitable for quantification of α-pinene in samples of essential oils since this method possessed the smallest R&R (1.81) value. PMID:26838386

  9. 1H NMR Metabolomics Analysis of Glioblastoma Subtypes

    PubMed Central

    Cuperlovic-Culf, Miroslava; Ferguson, Dean; Culf, Adrian; Morin, Pier; Touaibia, Mohamed

    2012-01-01

    Glioblastoma multiforme (GBM) is the most common form of malignant glioma, characterized by unpredictable clinical behaviors that suggest distinct molecular subtypes. With the tumor metabolic phenotype being one of the hallmarks of cancer, we have set upon to investigate whether GBMs show differences in their metabolic profiles. 1H NMR analysis was performed on metabolite extracts from a selection of nine glioblastoma cell lines. Analysis was performed directly on spectral data and on relative concentrations of metabolites obtained from spectra using a multivariate regression method developed in this work. Both qualitative and quantitative sample clustering have shown that cell lines can be divided into four groups for which the most significantly different metabolites have been determined. Analysis shows that some of the major cancer metabolic markers (such as choline, lactate, and glutamine) have significantly dissimilar concentrations in different GBM groups. The obtained lists of metabolic markers for subgroups were correlated with gene expression data for the same cell lines. Metabolic analysis generally agrees with gene expression measurements, and in several cases, we have shown in detail how the metabolic results can be correlated with the analysis of gene expression. Combined gene expression and metabolomics analysis have shown differential expression of transporters of metabolic markers in these cells as well as some of the major metabolic pathways leading to accumulation of metabolites. Obtained lists of marker metabolites can be leveraged for subtype determination in glioblastomas. PMID:22528487

  10. Single-Quantum Coherence Filter for Strongly Coupled Spin Systems for Localized 1H NMR Spectroscopy

    NASA Astrophysics Data System (ADS)

    Trabesinger, Andreas H.; Mueller, D. Christoph; Boesiger, Peter

    2000-08-01

    A pulse sequence for localized in vivo1H NMR spectroscopy is presented, which selectively filters single-quantum coherence built up by strongly coupled spin systems. Uncoupled and weakly coupled spin systems do not contribute to the signal output. Analytical calculations using a product operator description of the strongly coupled AB spin system as well as in vitro tests demonstrate that the proposed filter produces a signal output for a strongly coupled AB spin system, whereas the resonances of a weakly coupled AX spin system and of uncoupled spins are widely suppressed. As a potential application, the detection of the strongly coupled AA‧BB‧ spin system of taurine at 1.5 T is discussed.

  11. The origin of molecular mobility during biomass pyrolysis as revealed by in situ (1)H NMR spectroscopy.

    PubMed

    Dufour, Anthony; Castro-Diaz, Miguel; Brosse, Nicolas; Bouroukba, Mohamed; Snape, Colin

    2012-07-01

    The thermochemical conversion of lignocellulosic biomass feedstocks offers an important potential route for the production of biofuels and value-added green chemicals. Pyrolysis is the first phenomenon involved in all biomass thermochemical processes and it controls to a major extent the product composition. The composition of pyrolysis products can be affected markedly by the extent of softening that occurs. In spite of extensive work on biomass pyrolysis, the development of fluidity during the pyrolysis of biomass has not been quantified. This paper provides the first experimental investigation of proton mobility during biomass pyrolysis by in situ (1)H NMR spectroscopy. The origin of mobility is discussed for cellulose, lignin and xylan. The effect of minerals on cellulose mobility is also investigated. Interactions between polymers in the native biomass network are revealed by in situ (1)H NMR analysis. PMID:22573541

  12. Total (1)H NMR assignment of 3β-acetoxypregna-5,16-dien-20-one.

    PubMed

    Becerra-Martinez, Elvia; Ramírez-Gualito, Karla E; Pérez-Hernández, Nury; Joseph-Nathan, Pedro

    2015-12-01

    This work describes the total and unambiguous assignment of the 750 MHz (1)H NMR spectrum of 3β-acetoxypregna-5,16-dien-20-one or 16-DPA (1), the well-known intermediate utilized in the synthesis of biological important commercial steroids. The task was accomplished by extracting the coupling constant values in the overlapped spectrum region by HSQC, and using these values in the (1)H iterative full spin analysis integrated in the PERCH NMR software. Comparison of the experimental vicinal coupling constants of 1 with the values calculated using Altona provides an excellent correlation. The same procedure, when applied to the published data of progesterone (2) and testosterone (3), afforded an acceptable correlation for 2 and a poor correlation for 3. In the last case, this suggested the reassignment of all four vicinal coupling constants for the methylene signals at the C-15 and C-16 positions, demonstrating the utility of this methodology. PMID:26476187

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

    PubMed

    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%. PMID:26593470

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

    PubMed Central

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

    2016-01-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2010-01-01

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

  16. Improving Assessment of Lipoprotein Profile in Type 1 Diabetes by 1H NMR Spectroscopy

    PubMed Central

    Brugnara, Laura; Mallol, Roger; Ribalta, Josep; Vinaixa, Maria; Murillo, Serafín; Casserras, Teresa; Guardiola, Montse; Vallvé, Joan Carles; Kalko, Susana G.; Correig, Xavier; Novials, Anna

    2015-01-01

    Patients with type 1 diabetes (T1D) present increased risk of cardiovascular disease (CVD). The aim of this study is to improve the assessment of lipoprotein profile in patients with T1D by using a robust developed method 1H nuclear magnetic resonance spectroscopy (1H NMR), for further correlation with clinical factors associated to CVD. Thirty patients with T1D and 30 non-diabetes control (CT) subjects, matched for gender, age, body composition (DXA, BMI, waist/hip ratio), regular physical activity levels and cardiorespiratory capacity (VO2peak), were analyzed. Dietary records and routine lipids were assessed. Serum lipoprotein particle subfractions, particle sizes, and cholesterol and triglycerides subfractions were analyzed by 1H NMR. It was evidenced that subjects with T1D presented lower concentrations of small LDL cholesterol, medium VLDL particles, large VLDL triglycerides, and total triglycerides as compared to CT subjects. Women with T1D presented a positive association with HDL size (p<0.005; R = 0.601) and large HDL triglycerides (p<0.005; R = 0.534) and negative (p<0.005; R = -0.586) to small HDL triglycerides. Body fat composition represented an important factor independently of normal BMI, with large LDL particles presenting a positive correlation to total body fat (p<0.005; R = 0.505), and total LDL cholesterol and small LDL cholesterol a positive correlation (p<0.005; R = 0.502 and R = 0.552, respectively) to abdominal fat in T1D subjects; meanwhile, in CT subjects, body fat composition was mainly associated to HDL subclasses. VO2peak was negatively associated (p<0.005; R = -0.520) to large LDL-particles only in the group of patients with T1D. In conclusion, patients with T1D with adequate glycemic control and BMI and without chronic complications presented a more favourable lipoprotein profile as compared to control counterparts. In addition, slight alterations in BMI and/or body fat composition showed to be relevant to provoking alterations in

  17. Lemna minor L. as a model organism for ecotoxicological studies performing 1H NMR fingerprinting.

    PubMed

    Aliferis, Konstantinos A; Materzok, Sylwia; Paziotou, Georgia N; Chrysayi-Tokousbalides, Maria

    2009-08-01

    A validated method applying (1)H NMR fingerprinting for the study of metabolic changes caused in Lemna minor L. by various phytotoxic substances is presented. (1)H NMR spectra of crude extracts from untreated and treated colonies with the herbicides glyphosate, mesotrione, norflurazon, paraquat and the phytotoxin pyrenophorol were subjected to multivariate analyses for detecting differences between groups of treatments. Partial least squares-discriminant analysis (PLS-DA) and hierarchical cluster analysis (HCA) were carried out in order to discriminate and classify treatments according to the observed changes in the metabolome of the plant. Although the compounds at the concentrations used did not cause macroscopically observable symptoms of phytotoxicity, characteristic metabolic changes were detectable by analyzing (1)H NMR spectra. Analyses results revealed that metabonomics applying (1)H NMR fingerprinting is a potential method for the investigation of toxicological effects of xenobiotics on L. minor, and possibly on other duckweed species, helping in the understanding of such interactions. PMID:19443011

  18. 1H NMR spectra of humic and fulvic acids and their peracetic oxidation products

    NASA Astrophysics Data System (ADS)

    Ruggiero, P.; Interesse, F. S.; Cassidei, L.; Sciacovelli, O.

    1980-04-01

    1H NMR spectra of humic (HA) and fulvic (FA) acids and their oxidative degradation products are reported. The HA shows the presence of -( CH2) n - CH3 ( n > 6) chemical fragments belonging to n-alkanes and/or n-fatty acids physically adsorbed onto the macromolecule structure. These fragments are absent in the FA fraction. Both humic fractions reveal the presence of similar amounts of aromatic protons which partly undergo exchange phenomena. The importance of this experimental observation is discussed. Oxidative degradation seems to cause partial cleavage of aromatic rings, more pronounced in the FA than in the HA. The degraded FA shows a higher total acidity and a higher phenolic OH content than the degraded HA. Both degraded fractions display some sharp singlet signals at 1.9 and 3.9 ppm arising from protons belonging to repetitive chemical fragments probably formed during the oxidation reaction. Tentative assignments of these signals are given. A general analysis of the HA and FA degraded spectra seems to indicate that the chemical fragments which undergo peracetic oxidation are substantially similar. The extent of oxidation of the two humic fractions is different. The HA degradation products reveal the presence of oligomeric structures, whereas the degraded FA appears less resistant to the oxidizing agent.

  19. High Resolution Magic Angle Spinning 1H-NMR Metabolic Profiling of Nanoliter Biological Tissues at High Magnetic Field

    SciTech Connect

    Feng, Ju; Hu, Jian Z.; Burton, Sarah D.; Hoyt, David W.

    2013-03-05

    It is demonstrated that a high resolution magic angle spinning 1H-NMR spectrum of biological tissue samples with volumes as small as 150 nanoliters, or 0.15 mg in weight, can be acquired in a few minutes at 21.1 T magnetic field using a commercial 1.6 mm fast-MAS probe with minor modification of the MAS rotor. The strategies of sealing the samples inside the MAS rotor to avoid fluid leakage as well as the ways of optimizing the signal to noise are discussed.

  20. Simultaneous Structural Identification of Natural Products in Fractions of Crude Extract of the Rare Endangered Plant Anoectochilus roxburghii Using 1H NMR/RRLC-MS Parallel Dynamic Spectroscopy

    PubMed Central

    Wang, Xiao-Xue; He, Jiu-Ming; Wang, Chun-Lan; Zhang, Rui-Ping; He, Wen-Yi; Guo, Shun-Xing; Sun, Rui-Xiang; Abliz, Zeper

    2011-01-01

    Nuclear magnetic resonance/liquid chromatography-mass spectroscopy parallel dynamic spectroscopy (NMR/LC-MS PDS) is a method aimed at the simultaneous structural identification of natural products in complex mixtures. In this study, the method is illustrated with respect to 1H NMR and rapid resolution liquid chromatography-mass spectroscopy (RRLC-MS) data, acquired from the crude extract of Anoectochilus roxburghii, which was separated into a series of fractions with the concentration of constituent dynamic variation using reversed-phase preparative chromatography. Through fraction ranges and intensity changing profiles in 1H NMR/RRLC–MS PDS spectrum, 1H NMR and the extracted ion chromatogram (XIC) signals deriving from the same individual constituent, were correlated due to the signal amplitude co-variation resulting from the concentration variation of constituents in a series of incompletely separated fractions. 1H NMR/RRLC-MS PDS was then successfully used to identify three types of natural products, including eight flavonoids, four organic acids and p-hydroxybenzaldehyde, five of which have not previously been reported in Anoectochilus roxburghii. In addition, two groups of co-eluted compounds were successfully identified. The results prove that this approach should be of benefit in the unequivocal structural determination of a variety of classes of compounds from extremely complex mixtures, such as herbs and biological samples, which will lead to improved efficiency in the identification of new potential lead compounds. PMID:21731458

  1. Spatially localized sup 1 H NMR spectra of metabolites in the human brain

    SciTech Connect

    Hanstock, C.C. ); Rothman, D.L.; Jue, T.; Shulman, R.G. ); Prichard, J.W. )

    1988-03-01

    Using a surface coil, the authors have obtained {sup 1}H NMR spectra from metabolites in the human brain. Localization was achieved by combining depth pulses with image-selected in vivo spectroscopy magnetic field gradient methods. {sup 1}H spectra in which total creatine (3.03 ppm) has a signal/noise ratio of 95:1 were obtained in 4 min from 14 ml of brain. A resonance at 2.02 ppm consisting predominantly of N-acetylaspartate was measured relative to the creatine peak in gray and white matter, and the ratio was lower in the white matter. The spin-spin relaxation times of N-acetylaspartate and creatine were measured in white and gray matter and while creatine relaxation times were the same in both, the N-acetylaspartate relaxation time was longer in white matter. Lactate was detected in the normoxic brain and the average of three measurements was {approx}0.5 mM from comparison with the creatine plus phosphocreatine peak, which was assumed to be 10.5 mM.

  2. Differential osmotic behavior of water components in living skeletal muscle resolved by 1H-NMR.

    PubMed

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

    2005-08-01

    Using frog sartorius muscle, we observed transverse relaxation processes of (1)H-NMR signals from myowater. The process could be well described by four characteristic exponentials: the extremely slow exponential of relaxation time constant T(2) > 0.4 s, the slow one of T(2) approximately 0.15 s, the intermediate one of 0.03 s < T(2) < 0.06 s, and the rapid one of T(2) < 0.03 s. Addition of isotonic extracellular solution affected only the extremely slow exponential, linearly increasing its amplitude and gradually increasing its T(2) toward that of the bulk solution (1.7 s). Therefore, this exponential should represent extracellular surplus solution independently of the other exponentials. At two thirds to three times the isotonicity, the amplitude of the intermediate exponential showed normal osmotic behavior in parallel with the volume change of the myofilament lattice measured with x-ray diffraction. In the same tonicity range, the amplitude of the rapid exponential showed converse osmotic behavior. Lower tonicities increased the amplitude of only the slow exponential. Studied tonicities did not affect the T(2) values. The distinct osmotic behavior indicated that each characteristic exponential could be viewed as a distinct water group. In addition, the converse osmotic behavior suggested that the rapid exponential would not be a static water layer on the macromolecule surface. PMID:15894647

  3. Metabolic characterization of natural and cultured Ophicordyceps sinensis from different origins by 1H NMR spectroscopy.

    PubMed

    Zhang, Jianshuang; Zhong, Xin; Li, Shaosong; Zhang, Guren; Liu, Xin

    2015-11-10

    Ophicordyceps sinensis is a well-known traditional Chinese medicine and cultured mycelium is a substitute for wild O. sinensis. Metabolic profiles of wild O. sinensis from three geographical locations and cultivated mycelia derived from three origins were investigated using (1)H nuclear magnetic resonance (NMR) analysis combined with multivariate statistical analysis. A total of 56 primary metabolites were identified and quantified from O. sinensis samples. The principle component analysis (PCA) showed significant differences between natural O. sinensis and fermentation mycelia. Seven metabolites responsible for differentiation were screened out by orthogonal partial least squares discriminant analysis (OPLS-DA). The concentrations of mannitol, trehalose, arginine, trans-4-hydroxyproline, alanine and glucitol were significantly different between wild and cultured groups. The variation in metabolic profiling among artificial mycelia was greater than that among wild O. sinensis. Furthermore, wild samples from different origins were clearly distinguished by the levels of mannitol, trehalose and some amino acids. This study indicates that (1)H NMR-based metabolomics is useful for fingerprinting and discriminating O. sinensis of different geographical regions and cultivated mycelia of different strains. The present study provided an efficient approach for investigating chemical compositions and evaluating the quality of medicine and health food derived from O. sinensis. PMID:26279370

  4. Characterization of water-soluble organic matter in urban aerosol by 1H-NMR spectroscopy

    NASA Astrophysics Data System (ADS)

    Chalbot, Marie-Cecile G.; Chitranshi, Priyanka; Gamboa da Costa, Gonçalo; Pollock, Erik; Kavouras, Ilias G.

    2016-03-01

    The functional and 13C isotopic compositions of water-soluble organic carbon (WSOC) in atmospheric aerosol were determined by nuclear magnetic resonance (1H-NMR) and isotope ratio mass spectrometry (IRMS) in an urban location in the Southern Mississippi Valley. The origin of WSOC was resolved using the functional distribution of organic hydrogen, δ13C ratio, and positive matrix factorization (PMF). Three factors were retained based on NMR spectral bins loadings. Two factors (factors 1 and 3) demonstrated strong associations with the aliphatic region in the NMR spectra and levoglucosan resonances. Differences between the two factors included the abundance of the aromatic functional group for factor 1, indicating fresh emissions and, for factor 3, the presence of resonances attributed to secondary ammonium nitrate and low δ13C ratio values that are indicative of secondary organic aerosol. Factors 1 and 3 added 0.89 and 1.08 μgC m-3, respectively, with the highest contribution in the summer and fall. Factor 2 retained resonances consistent with saccharides and was attributed to pollen particles. Its contribution to WSOC varied from 0.22 μgC m-3 in winter to 1.04 μgC m-3 in spring.

  5. 1H NMR Metabolic Profiling of Biofluids from Rats with Gastric Mucosal Lesion and Electroacupuncture Treatment

    PubMed Central

    Xu, Jingjing; Cheng, Kian-Kai; Yang, Zongbao; Wang, Chao; Shen, Guiping; Wang, Yadong; Liu, Qiong; Dong, Jiyang

    2015-01-01

    Gastric mucosal lesion (GML) is a common gastrointestinal disorder with multiple pathogenic mechanisms in clinical practice. In traditional Chinese medicine (TCM), electroacupuncture (EA) treatment has been proven as an effective therapy for GML, although the underlying healing mechanism is not yet clear. Here, we used proton nuclear magnetic resonance- (1H NMR-) based metabolomic method to investigate the metabolic perturbation induced by GML and the therapeutic effect of EA treatment on stomach meridian (SM) acupoints. Clear metabolic differences were observed between GML and control groups, and related metabolic pathways were discussed by means of online metabolic network analysis toolbox. By comparing the endogenous metabolites from GML and GML-SM groups, the disturbed pathways were partly recovered towards healthy state via EA treated on SM acupoints. Further comparison of the metabolic variations induced by EA stimulated on SM and the control gallbladder meridian (GM) acupoints showed a quite similar metabolite composition except for increased phenylacetylglycine, 3,4-dihydroxymandelate, and meta-hydroxyphenylacetate and decreased N-methylnicotinamide in urine from rats with EA treated on SM acupoints. The current study showed the potential application of metabolomics in providing further insight into the molecular mechanism of acupuncture. PMID:26170882

  6. Studies of Secondary Melanoma on C57BL/6J Mouse Liver Using 1H NMR Metabolomics

    SciTech Connect

    Feng, Ju; Isern, Nancy G.; Burton, Sarah D.; Hu, Jian Z.

    2013-10-31

    NMR metabolomics, consisting of solid state high resolution (hr) magic angle spinning (MAS) 1H NMR (1H hr-MAS), liquid state high resolution 1H-NMR, and principal components analysis (PCA) has been used to study secondary metastatic B16-F10 melanoma in C57BL/6J mouse liver . The melanoma group can be differentiated from its control group by PCA analysis of the absolute concentrations or by the absolute peak intensities of metabolites from either 1H hr-MAS NMR data on intact liver tissues or liquid state 1H-NMR spectra on liver tissue extracts. In particular, we found that the absolute concentrations of alanine, glutamate, creatine, creatinine, fumarate and cholesterol are elevated in the melanoma group as compared to controls, while the absolute concentrations of succinate, glycine, glucose, and the family of linear lipids including long chain fatty acids, total choline and acylglycerol are decreased. The ratio of glycerophosphocholine to phosphocholine is increased by about 1.5 fold in the melanoma group, while the absolute concentration of total choline is actually lower in melanoma mice. These results suggest the following picture in secondary melanoma metastasis: Linear lipid levels are decreased by beta oxidation in the melanoma group, which contributes to an increase in the synthesis of cholesterol, and also provides an energy source input for TCA cycle. These findings suggest a link between lipid oxidation, the TCA cycle and the hypoxia-inducible factors (HIF) signal pathway in tumor metastases. Thus this study indicates that the metabolic profile derived from NMR analysis can provide a valuable bio-signature of malignancy and cell hypoxia in metastatic melanoma.

  7. Fruit juice authentication by 1H NMR spectroscopy in combination with different chemometrics tools.

    PubMed

    Cuny, M; Vigneau, E; Le Gall, G; Colquhoun, I; Lees, M; Rutledge, D N

    2008-01-01

    To discriminate orange juice from grapefruit juice in a context of fraud prevention, (1)H NMR data were submitted to different treatments to extract informative variables which were then analysed using multivariate techniques. Averaging contiguous data points of the spectrum followed by logarithmic transformation improved the results of the data analysis. Moreover, supervised variable selection methods gave better rates of classification of the juices into the correct groups. Last, independent-component analysis gave better classification results than principal-component analysis. Hence, ICA may be an efficient chemometric tool to detect differences in the (1)H NMR spectra of similar samples, and so may be useful for authentication of foods. PMID:18026939

  8. Binding of Sulfonamide Antibiotics to CTABr Micelles Characterized Using (1)H NMR Spectroscopy.

    PubMed

    Sarker, Ashish K; Cashin, Patrick J; Balakrishnan, Vimal K; Exall, Kirsten; Buncel, Erwin; Brown, R Stephen

    2016-08-01

    Interactions of nine sulfonamide antibiotics (sulfadoxine, sulfathiazole, sulfamethoxazole, sulfamerazine, sulfadiazine, sulfamethazine, sulfacetamide, sulfaguanidine, and sulfanilamide) with cetyltrimethylamonium bromide (CTABr) micelles were examined using (1)H NMR spectroscopy. Seven of the nine provided a significant change in the (1)H NMR chemical shift such that the magnitude and direction (upfield vs downfield) of the chemical shift could be used to propose a locus and orientation of the sulfonamide within the micelle structure. The magnitude of the chemical shift was used to estimate the binding constant for seven sulfonamides with CTABr micelles, providing values and an overall pattern consistent with previous studies of these sulfonamides. PMID:27391918

  9. Application of a quantitative (1)H-NMR method for the determination of paeonol in Moutan cortex, Hachimijiogan and Keishibukuryogan.

    PubMed

    Tanaka, Rie; Shibata, Hikari; Sugimoto, Naoki; Akiyama, Hiroshi; Nagatsu, Akito

    2016-10-01

    Quantitative (1)H-NMR ((1)H-qNMR) was applied to the determination of paeonol concentration in Moutan cortex, Hachimijiogan, and Keishibukuryogan. Paeonol is a major component of Moutan cortex, and its purity was calculated from the ratio of the intensity of the paeonol H-3' signal at δ 6.41 ppm in methanol-d 4 or 6.40 ppm in methanol-d 4 + TFA-d to that of a hexamethyldisilane (HMD) signal at 0 ppm. The concentration of HMD was corrected with SI traceability by using potassium hydrogen phthalate of certified reference material grade. As a result, the paeonol content in two lots of Moutan cortex as determined by (1)H-qNMR was found to be 1.59 % and 1.62 %, respectively, while the paeonol content in Hachimijiogan and Keishibukuryogan was 0.15 % and 0.22 %, respectively. The present study demonstrated that the (1)H-NMR method is useful for the quantitative analysis of crude drugs and Kampo formulas. PMID:27164909

  10. Evaluation of 1H NMR metabolic profiling using biofluid mixture design.

    PubMed

    Athersuch, Toby J; Malik, Shahid; Weljie, Aalim; Newton, Jack; Keun, Hector C

    2013-07-16

    A strategy for evaluating the performance of quantitative spectral analysis tools in conditions that better approximate background variation in a metabonomics experiment is presented. Three different urine samples were mixed in known proportions according to a {3, 3} simplex lattice experimental design and analyzed in triplicate by 1D (1)H NMR spectroscopy. Fifty-four urinary metabolites were subsequently quantified from the sample spectra using two methods common in metabolic profiling studies: (1) targeted spectral fitting and (2) targeted spectral integration. Multivariate analysis using partial least-squares (PLS) regression showed the latent structure of the spectral set recapitulated the experimental mixture design. The goodness-of-prediction statistic (Q(2)) of each metabolite variable in a PLS model was calculated as a metric for the reliability of measurement, across the sample compositional space. Several metabolites were observed to have low Q(2) values, largely as a consequence of their spectral resonances having low s/n or strong overlap with other sample components. This strategy has the potential to allow evaluation of spectral features obtained from metabolic profiling platforms in the context of the compositional background found in real biological sample sets, which may be subject to considerable variation. We suggest that it be incorporated into metabolic profiling studies to improve the estimation of matrix effects that confound accurate metabolite measurement. This novel method provides a rational basis for exploiting information from several samples in an efficient manner and avoids the use of multiple spike-in authentic standards, which may be difficult to obtain. PMID:23730812

  11. Metabolomic analysis of the plasma of patients with high-altitude pulmonary edema (HAPE) using 1H NMR.

    PubMed

    Luo, Yongjun; Zhu, Junyu; Gao, Yuqi

    2012-06-01

    Upon rapid ascent to a high altitude, non-acclimatized individuals, although healthy, are highly prone to contracting high-altitude pulmonary edema (HAPE). Early diagnosis is difficult and there is no reliable biomarker available. We used proton ((1)H) NMR metabolomics to profile the altered metabolic patterns of blood plasma from HAPE patients. The plasmas of ten patients with HAPE and ten individuals without HAPE were collected and compared using (1)H NMR spectroscopy. Data were evaluated with several multivariate statistical analyses, including the principal components, the orthogonal partial least-squares discriminant, and the orthogonal signal correction partial least-squares discriminant. Multivariate statistical analyses revealed a significant disparity between subjects with HAPE and those in the control group. Compared to the plasma of the controls, the HAPE patients had significant increases in valine, lysine, leucine, isoleucine, glycerol phosphoryl choline, glycine, glutamine, glutamic acid, creatinine, citrate, and methyl histidine. These were accompanied by decreases in α- and β-glucose, trimethylamine, and the metabolic products of lipids. The data demonstrate that metabolomics may be effective for the diagnosis of HAPE in the future, and can be used for further understanding HAPE pathogenesis. PMID:22498880

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

    NASA Astrophysics Data System (ADS)

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

    2010-09-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2016-08-01

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

  14. Development and Validation of Quantitative (1)H NMR Spectroscopy for the Determination of Total Phytosterols in the Marine Seaweed Sargassum.

    PubMed

    Zhang, Xiu-Li; Wang, Cong; Chen, Zhen; Zhang, Pei-Yu; Liu, Hong-Bing

    2016-08-10

    Knowledge of phytosterol (PS) contents in marine algae is currently lacking compared to those in terrestrial plants. The present studies developed a quantitative (1)H NMR method for the determination of the total PSs in Sargassum. The characteristic proton signal H-3α in PSs was used for quantification, and 2,3,4,5-tetrachloro-nitrobenzene was used as an internal standard. Seaweed samples could be recorded directly after total lipid extraction and saponification. The results showed that the PS contents in Sargassum fusiforme (788.89-2878.67 mg/kg) were significantly higher than those in Sargassum pallidum (585.33-1596.00 mg/kg). The variable contents in both species suggested that fixed raw materials are very important for future research and development. Orthogonal projection to latent structures discriminant analysis was carried out in the spectral region of δ 3.00-6.50 in the (1)H NMR spectrum. S. fusiforme and S. pallidum could be separated well, and the key sterol marker was fucosterol. PMID:27447194

  15. Molecular characterization of dissolved organic matter in glacial ice: coupling natural abundance 1H NMR and fluorescence spectroscopy.

    PubMed

    Pautler, Brent G; Woods, Gwen C; Dubnick, Ashley; Simpson, André J; Sharp, Martin J; Fitzsimons, Sean J; Simpson, Myrna J

    2012-04-01

    Glaciers and ice sheets are the second largest freshwater reservoir in the global hydrologic cycle, and the onset of global climate warming has necessitated an assessment of their contributions to sea-level rise and the potential release of nutrients to nearby aquatic environments. In particular, the release of dissolved organic matter (DOM) from glacier melt could stimulate microbial activity in both glacial ecosystems and adjacent watersheds, but this would largely depend on the composition of the material released. Using fluorescence and (1)H NMR spectroscopy, we characterize DOM at its natural abundance in unaltered samples from a number of glaciers that differ in geographic location, thermal regime, and sample depth. Parallel factor analysis (PARAFAC) modeling of DOM fluorophores identifies components in the ice that are predominantly proteinaceous in character, while (1)H NMR spectroscopy reveals a mixture of small molecules that likely originate from native microbes. Spectrofluorescence also reveals a terrestrial contribution that was below the detection limits of NMR; however, (1)H nuclei from levoglucosan was identified in Arctic glacier ice samples. This study suggests that the bulk of the DOM from these glaciers is a mixture of biologically labile molecules derived from microbes. PMID:22385100

  16. 1H NMR determination of urinary betaine in patients with premature vascular disease and mild homocysteinemia.

    PubMed

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

    1995-02-01

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

  17. Synthesis of stereospecifically deuterated desoxypodophyllotoxins and 1H-nmr assignment of desoxypodophyllotoxin

    NASA Technical Reports Server (NTRS)

    Pullockaran, A. J.; Kingston, D. G.; Lewis, N. G.

    1989-01-01

    [4 beta- 2H1]Desoxypodophyllotoxin [3], [4 alpha- 2H1]desoxypodophyllotoxin [4], and [4, 4- 2 H2]desoxypodophyllotoxin [9] were prepared from podophyllotoxin [1] via its chloride [5]. A complete assignment of the 1H-nmr spectrum of desoxypodophyllotoxin [2] was made on the basis of the spectra of the deuterated compounds [3] and [4].

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

    PubMed

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

    2013-10-14

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

  19. Molecular Structures from [superscript 1]H NMR Spectra: Education Aided by Internet Programs

    ERIC Educational Resources Information Center

    Debska, Barbara; Guzowska-Swider, Barbara

    2007-01-01

    The article presents the way in which freeware Internet programs can be applied to teach [superscript 1]H NMR spectroscopy. The computer programs described in this article are part of the educational curriculum that explores spectroscopy and spectra interpretation. (Contains 6 figures.)

  20. Quantification of Human Brain Metabolites from in Vivo1H NMR Magnitude Spectra Using Automated Artificial Neural Network Analysis

    NASA Astrophysics Data System (ADS)

    Hiltunen, Yrjö; Kaartinen, Jouni; Pulkkinen, Juhani; Häkkinen, Anna-Maija; Lundbom, Nina; Kauppinen, Risto A.

    2002-01-01

    Long echo time (TE=270 ms) in vivo proton NMR spectra resembling human brain metabolite patterns were simulated for lineshape fitting (LF) and quantitative artificial neural network (ANN) analyses. A set of experimental in vivo1H NMR spectra were first analyzed by the LF method to match the signal-to-noise ratios and linewidths of simulated spectra to those in the experimental data. The performance of constructed ANNs was compared for the peak area determinations of choline-containing compounds (Cho), total creatine (Cr), and N-acetyl aspartate (NAA) signals using both manually phase-corrected and magnitude spectra as inputs. The peak area data from ANN and LF analyses for simulated spectra yielded high correlation coefficients demonstrating that the peak areas quantified with ANN gave similar results as LF analysis. Thus, a fully automated ANN method based on magnitude spectra has demonstrated potential for quantification of in vivo metabolites from long echo time spectroscopic imaging.

  1. Metabolic Study of Breast MCF-7 Tumor Spheroids after Gamma Irradiation by 1H NMR Spectroscopy and Microimaging

    PubMed Central

    Palma, Alessandra; Grande, Sveva; Luciani, Anna Maria; Mlynárik, Vladimír; Guidoni, Laura; Viti, Vincenza; Rosi, Antonella

    2016-01-01

    Multicellular tumor spheroids are an important model system to investigate the response of tumor cells to radio- and chemotherapy. They share more properties with the original tumor than cells cultured as 2D monolayers do, which helps distinguish the intrinsic properties of monolayer cells from those induced during cell aggregation in 3D spheroids. The paper investigates some metabolic aspects of small tumor spheroids of breast cancer and their originating MCF-7 cells, grown as monolayer, by means of high–resolution (HR) 1H NMR spectroscopy and MR microimaging before and after gamma irradiation. The spectra of spheroids were characterized by higher intensity of mobile lipids, mostly neutral lipids, and glutamine (Gln) signals with respect to their monolayer cells counterpart, mainly owing to the lower oxygen supply in spheroids. Morphological changes of small spheroids after gamma-ray irradiation, such as loss of their regular shape, were observed by MR microimaging. Lipid signal intensity increased after irradiation, as evidenced in both MR localized spectra of the single spheroid and in HR NMR spectra of spheroid suspensions. Furthermore, the intense Gln signal from spectra of irradiated spheroids remained unchanged, while the low Gln signal observed in monolayer cells increased after irradiation. Similar results were observed in cells grown in hypoxic conditions. The different behavior of Gln in 2D monolayers and in 3D spheroids supports the hypothesis that a lower oxygen supply induces both an upregulation of Gln synthetase and a downregulation of glutaminases with the consequent increase in Gln content, as already observed under hypoxic conditions. The data herein indicate that 1H NMR spectroscopy can be a useful tool for monitoring cell response to different constraints. The use of spheroid suspensions seems to be a feasible alternative to localized spectroscopy since similar effects were found after radiation treatment. PMID:27200293

  2. 1H NMR Analysis of Cerebrospinal Fluid from Alzheimer's Disease Patients: An Example of a Possible Misinterpretation Due to Non-Adjustment of pH.

    PubMed

    Cruz, Thomas; Balayssac, Stéphane; Gilard, Véronique; Martino, Robert; Vincent, Christian; Pariente, Jérémie; Malet-Martino, Myriam

    2014-01-01

    Two publications from the same research group reporting on the detection of new possible biomarkers for the early diagnosis of Alzheimer's disease (AD), based on the analysis of cerebrospinal fluid samples (CSF) with 1H Nuclear Magnetic Resonance (NMR), are at the origin of the present study. The authors observed significant differences in 1H NMR spectra of CSF from AD patients and healthy controls and, thus, proposed some NMR signals (without attribution) as possible biomarkers. However, this work was carried out in non-standardized pH conditions. Our study aims at warning about a possible misinterpretation that can arise from 1H NMR analyses of CSF samples if pH adjustment is not done before NMR analysis. Indeed, CSF pH increases rapidly after removal and is subject to changes over conservation time. We first identify the NMR signals described by the authors as biomarkers. We then focus on the chemical shift variations of their NMR signals as a function of pH in both standard solutions and CSF samples. Finally, a principal component analysis of 1H NMR data demonstrates that the same CSF samples recorded at pH 8.1 and 10.0 are statistically differentiated. PMID:24958390

  3. 1H-NMR METABONOMICS ANALYSIS OF SERA DIFFERENTIATES BETWEEN MAMMARY TUMOR-BEARING MICE AND HEALTHY CONTROLS

    EPA Science Inventory

    Global analysis of 1H-NMR spectra of serum is an appealing approach for the rapid detection of cancer. To evaluate the usefulness of this method in distinguishing between mammary tumor-bearing mice and healthy controls, we conducted 1H-NMR metabonomic analyses on serum samples ob...

  4. Isolation by high-pressure liquid chromatography of cis-trans isomers of β-apo-12'-carotenal and determination of their configurations by 1H NMR spectroscopy

    NASA Astrophysics Data System (ADS)

    Hu, Ying; Mizoguchi, Tadashi; Kurimoto, Yoshitaka; Koyama, Yasushi

    1995-10-01

    High-pressure liquid chromatography of an isomeric mixture of β-apo-12'-carotenal, which was obtained by iodine-sensitized photo-isomerization, resolved eleven peaks of cis-trans isomers. The configurations of eight isomers, i.e., all-trans, 9-, 13-, 15-, 13'-mono-cis, and 9,13-, 9,13'- and 13,13'-di-cis, were determined by 1H NMR spectroscopy. 1H, 1H COSY and long-range 1H, 1H COSY spectra was used for the assignments of all the 1H signals. The isomerization shifts of the olefinic 1H signals and the NOE correlations, which were identified in the 1H, 1H NOESY spectra, were used for the configurational determinations. In relation to the difference in isomeric composition between retinoids and carotenoids, the cis configurations found in the present compound (C 25 aldehyde) are compared with those found in retinal (C 20 aldehyde) and β-apo-8'-carotenal (C 30 aldehyde) having a shorter and a longer conjugated chain, respectively.

  5. 1H NMR profiling as an approach to differentiate conventionally and organically grown tomatoes.

    PubMed

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

    2014-08-20

    This study describes the approach of (1)H NMR profiling for the authentication of organically produced tomatoes (Solanum lycopersicum). Overall, 361 tomato samples of two different cultivars and four different producers were regularly analyzed during a 7 month period. The results of principal component analysis showed a significant trend for the separation between organically and conventionally produced tomatoes (p < 0.001 using the t test). Linear discriminant analysis demonstrated good discrimination between the growing regimens, and external validation showed 100% correctly classified tomato samples. Further validation studies, however, also disclosed unexpected differences between individual producers, which interfere with the aim of predicting the cultivation method, yet the results indicate significant differences between (1)H NMR spectra of organically and conventionally grown tomatoes. PMID:25066078

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

    PubMed

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

    2015-04-15

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

  7. Study on 1H-NMR fingerprinting of Rhodiolae Crenulatae Radix et Rhizoma.

    PubMed

    Wen, Shi-yuan; Zhou, Jiang-tao; Chen, Yan-yan; Ding, Li-qin; Jiang, Miao-miao

    2015-07-01

    Nuclear magnetic resonance (1H-NMR) fingerprint of Rhodiola rosea medicinal materials was established, and used to distinguish the quality of raw materials from different sources. Pulse sequence for water peak inhibition was employed to acquire 1H-NMR spectra with the temperature at 298 K and spectrometer frequency of 400.13 MHz. Through subsection integral method, the obtained NMR data was subjected to similarity analysis and principal component analysis (PCA). 10 batches raw materials of Rhodiola rosea from different origins were successfully distinguished by PCA. The statistical results indicated that rhodiola glucoside, butyl alcohol, maleic acid and alanine were the main differential ingredients. This method provides an auxiliary method of Chinese quality approach to evaluate the quality of Rhodiola crenulata without using natural reference substances. PMID:26697690

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

    PubMed

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

    2010-08-01

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

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

    PubMed

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

    2014-01-01

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

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

    PubMed Central

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

    2014-01-01

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

  11. (1)H NMR foodomics reveals that the biodynamic and the organic cultivation managements produce different grape berries (Vitis vinifera L. cv. Sangiovese).

    PubMed

    Picone, Gianfranco; Trimigno, Alessia; Tessarin, Paola; Donnini, Silvia; Rombolà, Adamo Domenico; Capozzi, Francesco

    2016-12-15

    The increasing demand for natural foods and beverages, i.e. prepared by excluding synthetic chemicals along the whole production chain, has boosted the adoption of organic and biodynamic cultivation methods which are based on protocols avoiding use of synthetic pesticides. This trend is striking in viticulture, since wine production is largely shaped by the varying drinking attitudes of environment-friendly consumers. Using (1)H NMR, the compositions of grape berries, collected at harvest in 2009 and 2011, in experimental plots cultivated either with biodynamic or organic methods, were compared. Although the analysis provides a comprehensive metabolic profile of berries, the resulting distinctive pattern consists of a few molecules. Lower content of sugars, coumaric and caffeic acids, as well as higher amount of γ-aminobutyric acid (GABA) were observed in biodynamic grapes. The (1)H NMR foodomics approach evidenced a diverse fruit metabolome that could be associated to a different physiological response of plants to the agronomic environment. PMID:27451171

  12. Metabolic fingerprinting of Leontopodium species (Asteraceae) by means of 1H NMR and HPLC–ESI-MS

    PubMed Central

    Safer, Stefan; Cicek, Serhat S.; Pieri, Valerio; Schwaiger, Stefan; Schneider, Peter; Wissemann, Volker; Stuppner, Hermann

    2011-01-01

    The genus Leontopodium, mainly distributed in Central and Eastern Asia, consists of ca. 34–58 different species. The European Leontopodium alpinum, commonly known as Edelweiss, has a long tradition in folk medicine. Recent research has resulted in the identification of prior unknown secondary metabolites, some of them with interesting biological activities. Despite this, nearly nothing is known about the Asian species of the genus. In this study, we applied proton nuclear magnetic resonance (1H NMR) spectroscopy and liquid chromatography–mass spectrometry (LC–MS) metabolic fingerprinting to reveal insights into the metabolic patterns of 11 different Leontopodium species, and to conclude on their taxonomic relationship. Principal component analysis (PCA) of 1H NMR fingerprints revealed two species groups. Discriminators for these groups were identified as fatty acids and sucrose for group A, and ent-kaurenoic acid and derivatives thereof for group B. Five diterpenes together with one sesquiterpene were isolated from Leontopodium franchetii roots; the compounds were described for the first time for L. franchetii: ent-kaur-16-en-19-oic acid, methyl-15α-angeloyloxy-ent-kaur-16-en-19-oate, methyl-ent-kaur-16-en-19-oate, 8-acetoxymodhephene, 19-acetoxy-ent-kaur-16-ene, methyl-15β–angeloyloxy-16,17-epoxy-ent-kauran-19-oate. In addition, differences in the metabolic profile between collected and cultivated species could be observed using a partial least squares-discriminant analysis (PLS-DA). PCA of the LC–MS fingerprints revealed three groups. Discriminating signals were compared to literature data and identified as two bisabolane derivatives responsible for discrimination of group A and C, and one ent-kaurenoic acid derivative, discriminating group B. A taxonomic relationship between a previously unidentified species and L. franchetii and Leontopodium sinense could be determined by comparing NMR fingerprints. This finding supports recent molecular data

  13. Quantitative Quantum Mechanical Spectral Analysis (qQMSA) of 1H NMR spectra of complex mixtures and biofluids

    NASA Astrophysics Data System (ADS)

    Tiainen, Mika; Soininen, Pasi; Laatikainen, Reino

    2014-05-01

    The quantitative interpretation of 1H NMR spectra of mixtures like the biofluids is a demanding task due to spectral complexity and overlap. Complications may arise also from water suppression, T2-editing, protein interactions, relaxation differences of the species, experimental artifacts and, furthermore, the spectra may contain unknown components and macromolecular background which cannot be easily separated from baseline. In this work, tools and strategies for quantitative Quantum Mechanical Spectral Analysis (qQMSA) of 1H NMR spectra from complex mixtures were developed and systematically assessed. In the present approach, the signals of well-defined, stoichiometric components are described by a QM model, while the background is described by a multiterm baseline function and the unknown signals using optimizable and adjustable lines, regular multiplets or any spectral structures which can be composed from spectral lines. Any prior knowledge available from the spectrum can also be added to the model. Fitting strategies for weak and strongly overlapping spectral systems were developed and assessed using two basic model systems, the metabolite mixtures without and with macromolecular (serum) background. The analyses show that if the spectra are measured in high-throughput manner, the consistent absolute quantification demands some calibration to compensate the different response factors of the protons and compounds. On the other hand, the results show that also the T2-edited spectra can be measured so that they obey well the QM rules. In general, qQMSA exploits and interprets the spectral information in maximal way taking full advantage from the QM properties of the spectra and, at the same time, offers chemical confidence which means that individual components can be identified with high confidence on the basis of their accurate spectral parameters.

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

    PubMed

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

    2016-03-01

    Introduction - 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. Objectives - 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. Material and Methods - 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. Results - 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). Conclusion - 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. PMID:26763752

  15. Prognosis Biomarkers of Severe Sepsis and Septic Shock by 1H NMR Urine Metabolomics in the Intensive Care Unit

    PubMed Central

    Modesto-Alapont, Vicente; Gonzalez-Marrachelli, Vannina; Vento-Rehues, Rosa; Jorda-Miñana, Angela; Blanquer-Olivas, Jose; Monleon, Daniel

    2015-01-01

    Early diagnosis and patient stratification may improve sepsis outcome by a timely start of the proper specific treatment. We aimed to identify metabolomic biomarkers of sepsis in urine by 1H-NMR spectroscopy to assess the severity and to predict outcomes. Urine samples were collected from 64 patients with severe sepsis or septic shock in the ICU for a 1H NMR spectra acquisition. A supervised analysis was performed on the processed spectra, and a predictive model for prognosis (30-days mortality/survival) of sepsis was constructed using partial least-squares discriminant analysis (PLS-DA). In addition, we compared the prediction power of metabolomics data respect the Sequential Organ Failure Assessment (SOFA) score. Supervised multivariate analysis afforded a good predictive model to distinguish the patient groups and detect specific metabolic patterns. Negative prognosis patients presented higher values of ethanol, glucose and hippurate, and on the contrary, lower levels of methionine, glutamine, arginine and phenylalanine. These metabolites could be part of a composite biopattern of the human metabolic response to sepsis shock and its mortality in ICU patients. The internal cross-validation showed robustness of the metabolic predictive model obtained and a better predictive ability in comparison with SOFA values. Our results indicate that NMR metabolic profiling might be helpful for determining the metabolomic phenotype of worst-prognosis septic patients in an early stage. A predictive model for the evolution of septic patients using these metabolites was able to classify cases with more sensitivity and specificity than the well-established organ dysfunction score SOFA. PMID:26565633

  16. Reversible proton transfer phenomenon in the 2,4-dichlorophenol-triethylamine hydrogen-bonded complex studied by low-temperature 1H NMR spectroscopy

    NASA Astrophysics Data System (ADS)

    Ilczyszyn, Marek; Ratajczak, Henryk; Ladd, John A.

    1988-12-01

    Low-temperature 1H NMR studies of the bridging OHN signal in the hydrogen-bonded complex formed between 2,4-dichlorophenol and triethylamine in C 2H 5Cl solution have demonstrated for the first time that separate signals for the molecular and ion-pair forms of this type of system can be observed. The temperature dependence of these signals leads to thermodynamic and kinetic quantities which suggest that the potential energy profile of the hydrogen bond is roughly symmetric with a double minimum.

  17. Identifying metabolites related to nitrogen mineralisation using 1H NMR spectroscopy

    NASA Astrophysics Data System (ADS)

    . T McDonald, Noeleen; Graham, Stewart; Watson, Catherine; Gordon, Alan; Lalor, Stan; Laughlin, Ronnie; Elliott, Chris; . P Wall, David

    2015-04-01

    Exploring new analysis techniques to enhance our knowledge of the various metabolites within our soil systems is imperative. Principally, this knowledge would allow us to link key metabolites with functional influences on critical nutrient processes, such as the nitrogen (N) mineralisation in soils. Currently there are few studies that utilize proton nuclear magnetic resonance spectroscopy (1H NMR) to characterize multiple metabolites within a soil sample. The aim of this research study was to examine the effectiveness of 1H NMR for isolating multiple metabolites that are related to the mineralizable N (MN) capacity across a range of 35 Irish grassland soils. Soils were measured for MN using the standard seven day anaerobic incubation (AI-7). Additionally, soils were also analysed for a range of physio-chemical properties [e.g. total N, total C, mineral N, texture and soil organic matter (SOM)]. Proton NMR analysis was carried on these soils by extracting with 40% methanol:water, lyophilizing and reconstituting in deuterium oxide and recording the NMR spectra on a 400MHz Bruker AVANCE III spectrometer. Once the NMR data were spectrally processed and analysed using multivariate statistical analysis, seven metabolites were identified as having significant relationships with MN (glucose, trimethylamine, glutamic acid, serine, aspartic acid, 4-aminohippuirc acid and citric acid). Following quantification, glucose was shown to explain the largest percentage variability in MN (72%). These outcomes suggest that sources of labile carbon are essential in regulating N mineralisation and the capacity of plant available N derived from SOM-N pools in these soils. Although, smaller in concentration, the amino acids; 4-aminohippuirc acid, glutamic acid and serine also significantly (P<0.05) explained 43%, 27% and 19% of the variability in MN, respectively. This novel study highlights the effectiveness of using 1H NMR as a practical approach to profile multiple metabolites in

  18. Preparation of the UNDERC 200 MHz /sup 1/H NMR spectral catalog, Volume II

    SciTech Connect

    Gaides, G.E.; Farnum, S.A.; Wolfson, A.C.; Farnum, B.W.

    1984-01-01

    High resolution 200 MHz /sup 1/H NMR is used extensively to identify the components of complex low-rank coal-derived materials. We have compiled a catalog of 302 spectra of standards: (1) and are compiling a second, similar volume of 125 additional spectra. Many of these new compounds have only recently become available from commercial suppliers, or by synthesis. Like the previous catalog, Volume II is divided into two sections: a tabular section of all the compounds with their correct names, structure, and a line list of the chemical shifts, and a section which contains the actual spectra. Each section is arranged by functional group, for example, alkanes, phenols, etc. in order of their chromatographic elution. There is also an appendix which lists the suppliers of all the compounds in the catalog. Volume II contains several features not incorporated in the original catalog. We have added an alphabetical listing of all the compounds in both NMR catalogs, as well as formula and molecular weight indices. An added feature of this volume is the expanded coverage of nitrogen-containing compounds. Though there are many /sup 1/H NMR spectral catalogs in print, there are none that contain spectra run on 200 MHz spectrometers. Many spectra that appear complex at 60 MHz become first order at 200 MHz, facilitating their interpretation. At the UNDERC the majority of our samples are extremely complex mixtures. The simplification of the spectra of the individual components is necessary to characterize these coal-derived liquids. Another advantage of /sup 1/H NMR spectra run at 200 MHz is the greater than eleven-fold increase in sensitivity over those run at 60 MHz (2). Smaller, or more dilute samples may therefore be utilized. 2 references, 1 figure.

  19. Determination of metabolite profiles in tropical wines by 1H NMR spectroscopy and chemometrics.

    PubMed

    da Silva Neto, Humberto G; da Silva, João B P; Pereira, Giuliano E; Hallwass, Fernando

    2009-12-01

    Traditionally, wines are produced in temperate climate zones, with one harvest per year. Tropical wines are a new concept of vitiviniculture that is being developed, principally in Brazil. The new Brazilian frontier is located in the northeast region (São Francisco River Valley) in Pernambuco State, close to the equator, between 8 and 9 degrees S. Compared with other Brazilian and worldwide vineyards, the grapes of this region possess peculiar characteristics. The aim of this work is a preliminary study of commercial São Francisco River Valley wines, analyzing their metabolite profiles by (1)H NMR and chemometric methods. PMID:19810052

  20. 1H NMR investigation of self-association of vanillin in aqueous solution

    NASA Astrophysics Data System (ADS)

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

    2009-08-01

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

  1. Intermolecular Interactions between Eosin Y and Caffeine Using (1)H-NMR Spectroscopy.

    PubMed

    Okuom, Macduff O; Wilson, Mark V; Jackson, Abby; Holmes, Andrea E

    2013-12-31

    DETECHIP has been used in testing analytes including caffeine, cocaine, and tetrahydrocannabinol (THC) from marijuana, as well as date rape and club drugs such as flunitrazepam, gamma-hydroxybutyric acid (GHB), and methamphetamine. This study investigates the intermolecular interaction between DETECHIP sensor eosin Y (DC1) and the analyte (caffeine) that is responsible for the fluorescence and color changes observed in the actual array. Using (1)H-NMR, (1)H-COSY, and (1)H-DOSY NMR methods, a proton exchange from C-8 of caffeine to eosin Y is proposed. PMID:25018772

  2. 1H-NMR study of the spin dynamics of fine superparamagnetic nanoparticles

    SciTech Connect

    Bordonali, L.; Furukawa, Y.; Kraken, M.; Litterst, F.J.; Sangregorio, C.; Casula, M.F.; Lascialfari, A.

    2012-05-25

    We report a broadband 1H-NMR study of the temperature spin dynamics of nearly monodisperse dextran-coated γ-Fe2O3 magnetic nanoparticles. We observed a maximum in T1−1(T) that decreases in amplitude and shifts toward higher temperatures with increasing field. We suggest that this is related to the progressive superparamagnetic spin blocking of the ferrite core. The data can be explained by assuming a single electronic spin-spin correlation time and introducing a field-dependent distribution of anisotropy energy barriers.

  3. Intermolecular Interactions between Eosin Y and Caffeine Using 1H-NMR Spectroscopy

    PubMed Central

    Okuom, Macduff O.; Wilson, Mark V.; Jackson, Abby; Holmes, Andrea E.

    2014-01-01

    DETECHIP has been used in testing analytes including caffeine, cocaine, and tetrahydrocannabinol (THC) from marijuana, as well as date rape and club drugs such as flunitrazepam, gamma-hydroxybutyric acid (GHB), and methamphetamine. This study investigates the intermolecular interaction between DETECHIP sensor eosin Y (DC1) and the analyte (caffeine) that is responsible for the fluorescence and color changes observed in the actual array. Using 1H-NMR, 1H-COSY, and 1H-DOSY NMR methods, a proton exchange from C-8 of caffeine to eosin Y is proposed. PMID:25018772

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

    PubMed

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

    2015-05-15

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

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

    SciTech Connect

    Wilson, Jennifer C.; Laloo, Andrew Elohim; Singh, Sanjesh; Ferro, Vito

    2014-01-03

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

  6. Toxicity assessment of Arisaematis Rhizoma in rats by a (1)H NMR-based metabolomics approach.

    PubMed

    Dong, Ge; Wang, Junsong; Guo, Pingping; Wei, Dandan; Yang, Minghua; Kong, Lingyi

    2015-02-01

    Arisaematis Rhizoma (AR), a famous traditional Chinese medicine, has been widely used in Asia over thousands of years. Documented with noticeable toxicity in ancient books, AR has been used to treat various diseases in the clinic. Therefore, it is important to assess the toxicity of AR dynamically and holistically. In this study, a (1)H NMR-based metabolomics approach complemented with serum chemistry and histopathology has been applied to investigate the toxicity of AR. Rats were intragastrically administered with AR (0, 0.5 and 1 g kg(-1) body weight) for 30 days, and serum and urine samples were collected. Their (1)H NMR profiles were analyzed by multivariate pattern recognition techniques to denote metabolic variations induced by AR, and 13 metabolites in urine and 6 metabolites in serum were significantly altered, which suggested that disturbances in energy metabolism, perturbation of the gut microflora environment, membrane damage, folate deficiency and injury of kidneys are produced by AR. Histopathology showed a slight vacuolization of the glomerular matrix and edema of renal tubular epithelial cells in kidneys of AR administered rats, which were evidenced by increased levels of blood urea nitrogen and creatinine in serum chemistry. Our results indicated that oral administration of crude AR was found to induce slight renal toxicity. Therefore, precautions should be made to monitor the potential nephrotoxicity of AR in clinical use. The metabolomics approach provided a promising tool for the study and better understanding of TCM-induced toxicity dynamically and holistically. PMID:25407163

  7. High resolution 1H NMR of a lipid cubic phase using a solution NMR probe

    NASA Astrophysics Data System (ADS)

    Boyle-Roden, E.; Hoefer, N.; Dey, K. K.; Grandinetti, P. J.; Caffrey, M.

    2007-11-01

    The cubic mesophase formed by monoacylglycerols and water is an important medium for the in meso crystallogenesis of membrane proteins. To investigate molecular level lipid and additive interactions within the cubic phase, a method was developed for improving the resolution of 1H NMR spectra when using a conventional solution state NMR probe. Using this approach we obtained well-resolved J-coupling multiplets in the one-dimensional NMR spectrum of the cubic-Ia3d phase prepared with hydrated monoolein. A high resolution t-ROESY two-dimensional 1H NMR spectrum of the cubic-Ia3d phase is also reported. Using this new methodology, we have investigated the interaction of two additive molecules, L-tryptophan and ruthenium-tris(2,2-bipyridyl) dichloride (rubipy), with the cubic mesophase. Based on the measured chemical shift differences when changing from an aqueous solution to the cubic phase, we conclude that L-tryptophan experiences specific interactions with the bilayer interface, whereas rubipy remains in the aqueous channels and does not associate with the lipid bilayer.

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

    PubMed Central

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

    2015-01-01

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

  9. Two-dimensional /sup 1/H NMR studies on cyclophilin, a cytosolic cyclosporin A binding protein

    SciTech Connect

    Dalgarno, D.C.; Harding, M.W.; Lazarides, A.; Handschumacher, R.E.; Armitage, I.M.

    1986-05-01

    Cyclophilin (CyP) is a specific cytosolic cyclosporin A (CsA) binding protein (163 residues) that has been implicated in the pharmacological action of this potent immunosuppressant. One and two-dimensional /sup 1/H NMR methods are being employed to elucidate the solution structural properties of CyP particularly as they relate to the binding site of CsA. The focal point for these studies is the single Trp (residue number120) in CyP which, in the 1:1 CyP:CsA complex (K/sub d/approx.2 x 10/sup -7/M), shows a 2 fold enhancement in its intrinsic fluorescence. Using 2D /sup 1/H NMR methods, a low resolution structure has been derived for a very hydrophobic domain containing the Trp residue using interresidue n.O.e. data between assigned spin systems and a distance geometry algorithm. The structure of this hydrophobic domain will be discussed in relation to the predicted ..cap alpha../..beta.. secondary structure of this protein and comparisons made between its structure in the drug free and complexed form of the protein.

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

    PubMed

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

    2014-12-01

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

  11. Determination of the illicit drug gamma-hydroxybutyrate (GHB) in human saliva and beverages by 1H NMR analysis.

    PubMed

    Grootveld, Martin; Algeo, Deborah; Silwood, Christopher J L; Blackburn, John C; Clark, Anthony D

    2006-01-01

    High resolution 1H NMR spectroscopy has been employed to investigate the detection and quantification of the illicit "date-rape" drug gamma-hydroxybutyrate (GHB) in both human saliva and a commonly-consumed low-alcohol beer product. Data acquired revealed that this multicomponent analytical technique provided unequivocal evidence for the detection of this agent by this technique in both of these matrices, i.e., all three of its resonances [those ascribable to the alpha-CH2 (t, delta=2.25 ppm), beta-CH2 (tt, delta=1.81 ppm) and gamma-CH2 (t, delta=3.61 ppm) group protons] were present in spectra acquired on human saliva, and two of these (the alpha- and beta-CH2 group signals) in the beverage product examined, the latter observation attributable to overlap of the gamma-CH2 1H resonance with those of carbohydrates. Since good linear calibration relationships between the intensities of each of the NMR-visible signals and added GHB concentration (the former normalised to that of an external 3-trimethylsilyl [2,2,3,3-2H4]- propionate standard present in a coaxial NMR tube insert) were observed, this illicit drug is also readily quantifiable in such multicomponent samples. Our data demonstrate the advantages offered by this technique when applied to the analysis of illicit drugs in multicomponent sample matrices such as human biofluids and beverage products. PMID:17012769

  12. Quantitative determination of carboxylic acids, amino acids, carbohydrates, ethanol and hydroxymethylfurfural in honey by (1)H NMR.

    PubMed

    del Campo, Gloria; Zuriarrain, Juan; Zuriarrain, Andoni; Berregi, Iñaki

    2016-04-01

    A method using (1)H NMR spectroscopy has been developed to quantify simultaneously thirteen analytes in honeys without previous separation or pre-concentration steps. The method has been successfully applied to determine carboxylic acids (acetic, formic, lactic, malic and succinic acids), amino acids (alanine, phenylalanine, proline and tyrosine), carbohydrates (α- and β-glucose and fructose), ethanol and hydroxymethylfurfural in eucalyptus, heather, lavender, orange blossom, thyme and rosemary honeys. Quantification was performed by using the area of the signal of each analyte in the honey spectra, together with external standards. The regression analysis of the signal area against concentration plots, used for the calibration of each analyte, indicates a good linearity over the concentration ranges found in honeys, with correlation coefficients higher than 0.985 for the thirteen quantified analytes. The recovery studies give values over the 93.7-105.4% range with relative standard deviations lower than 7.4%. Good precision, with relative standard deviations over the range of 0.78-5.21% is obtained. PMID:26593586

  13. 1H NMR Relaxation Investigation of Inhibitors Interacting with Torpedo californica Acetylcholinesterase

    NASA Astrophysics Data System (ADS)

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

    2000-05-01

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

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

    PubMed

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

    2017-02-01

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

  15. (1)H NMR spectroscopy in the diagnosis of Pseudomonas aeruginosa-induced urinary tract infection.

    PubMed

    Gupta, Ashish; Dwivedi, Mayank; Nagana Gowda, G A; Ayyagari, Archana; Mahdi, A A; Bhandari, M; Khetrapal, C L

    2005-08-01

    The utility of (1)H NMR spectroscopy is suggested and demonstrated for the diagnosis of Pseudomonas aeruginosa in urinary tract infection (UTI). The specific property of P. aeruginosa of metabolizing nicotinic acid to 6-hydroxynicotinic acid (6-OHNA) is exploited. The quantity of 6-OHNA produced correlates well with the viable bacterial count. Other common bacteria causing UTI such as Escherichia coli, Klebsiella pneumonia, Enterobacter aerogenes, Acinetobacter baumanii, Proteus mirabilis, Citrobacter frundii, Enterococcus faecalis, Streptococcus gp B and Staphylococcus aureus do not metabolize nicotinic acid under similar conditions. The method provides a single-step documentation of P. aeruginosa qualitatively as well as quantitatively. The NMR method is demonstrated on urine samples from 30 patients with UTI caused by P. aeruginosa. PMID:15759292

  16. {sup 1}H NMR electron-nuclear cross relaxation in thin films of hydrogenated amorphous silicon

    SciTech Connect

    Su Tining; Taylor, P. C.; Ganguly, G.; Carlson, D. E.; Bobela, D. C.; Hari, P.

    2007-12-15

    We investigate the spin-lattice relaxation of the dipolar order in {sup 1}H NMR in hydrogenated amorphous silicon (a-Si:H). We find that the relaxation is dominated by the cross relaxation between the hydrogen nuclei and the paramagnetic states. The relaxation is inhomogeneous, and can be described as a stretched exponential function. We proposed a possible mechanism for this relaxation. This mechanism applies to a rather broad range of paramagnetic states, including the deep neutral defects (dangling bonds), the light-induced metastable defects, the defects created by doping, and the singly occupied, localized band-tail states populated by light at low temperatures. The cross relaxation is only sensitive to the bulk spin density, and the surface spins have a negligible effect on the relaxation.

  17. 1H NMR Cryoporometry Study of the Melting Behavior of Water in White Cement

    NASA Astrophysics Data System (ADS)

    Boguszyńska, Joanna; Tritt-Goc, Jadwiga

    2004-09-01

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

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

    PubMed

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

    2014-05-01

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

  19. Quantitative 1H NMR: Development and Potential of an Analytical Method – an Update

    PubMed Central

    Pauli, Guido F.; Gödecke, Tanja; Jaki, Birgit U.; Lankin, David C.

    2012-01-01

    Covering the literature from mid-2004 until the end of 2011, this review continues a previous literature overview on quantitative 1H NMR (qHNMR) methodology and its applications in the analysis of natural products (NPs). Among the foremost advantages of qHNMR is its accurate function with external calibration, the lack of any requirement for identical reference materials, a high precision and accuracy when properly validated, and an ability to quantitate multiple analytes simultaneously. As a result of the inclusion of over 170 new references, this updated review summarizes a wealth of detailed experiential evidence and newly developed methodology that supports qHNMR as a valuable and unbiased analytical tool for natural product and other areas of research. PMID:22482996

  20. 1H NMR study of the complexation of aromatic drugs with dimethylxanthine derivatives

    NASA Astrophysics Data System (ADS)

    Hernandez Santiago, A. A.; Gonzalez Flores, M.; Rosas Castilla, S. A.; Cervantes Tavera, A. M.; Gutierrez Perez, R.; Khomich, V. V.; Ovchinnikov, D. V.; Parkes, H. G.; Evstigneev, M. P.

    2012-02-01

    With an aim of searching efficient interceptors of aromatic drugs, the self- and hetero-association of dimethylxanthine derivatives with different structures, selected according to Strategy 1 (variation of the position of methyl groups) and Strategy 2 (variation of the length of sbnd (CH2)nsbnd COOH group), with aromatic drug molecules: Ethidium Bromide, Proflavine and Daunomycin, were studied using 1H NMR spectroscopy. It was found that the association proceeds in a form of stacking-type complexation and its energetics is relatively independent on the structure of the dimethylxanthines. However, on average, the dimethylxanthines possess higher hetero-association constant and, hence, higher interceptor ability as compared to the trimethylxanthine, Caffeine, used during the past two decades as a typical interceptor molecule.

  1. Interaction of Daunomycin with Dipalmitoylphosphatidylcholine Model Membranes. A 1H NMR Study

    NASA Astrophysics Data System (ADS)

    Calzolai, Luigi; Gaggelli, Elena; Maccotta, Antonella; Valensin, Gianni

    1996-09-01

    1H NMR parameters were obtained for daunomycin in water solution in the free state as well as in the presence of dipalmitoylphosphatidylcholine model membranes. Spin-lattice relaxation rates were measured under nonselective, single-selective, and double-selective irradiation modes, and 2D NOESY spectra were obtained at several values of the mixing time. Proton-proton distances were calculated and the motional correlation time was evaluated in both the free and bound states. NMR parameters were used to show that ring A and the glucosamine moiety of daunomycin strongly interact with the external surface of the bilayer, while the rest of the molecule penetrates the membrane without crossing it. The structures of both free and bound daunomycin were obtained and compared by using molecular modeling.

  2. 1H NMR metabolomics of earthworm responses to polychlorinated biphenyl (PCB) exposure in soil.

    PubMed

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

    2011-06-01

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

  3. Use of /sup 1/H NMR to study molecular motion in cellulose, pectin, and bean cell walls

    SciTech Connect

    Taylor, I.E.P.; Tepfer, M.; Callaghan, P.T.; MacKay, A.L.; Bloom, M.

    1983-01-01

    Growing plant cells are enclosed in a framework, the cell wall, whose rigidity must be overcome for cell enlargement to occur. It has been shown that one of the primary modes of action of plant growth substances is to induce cell wall loosening. The mechansim of cell wall loosening is very poorly understood and may involve large-scale changes in the molecular mobility of the cell wall polysaccharides. Proton magnetic resonance (/sup 1/H NMR) was used to study molecular motion in bean stem cell walls as well as in cellulose, sodium pectate solutions, and calcium pectate gels. All samples were prepared in K/sub 2/O to minimize the contribution of water to the observed signals. The different NMR properties that have been measured are sensitive to molecular motions over a wide range of frequencies (10 kHz-90 MHz). For each sample, a free induction decay was obtained and the second moment as well as spin-lattice (longitudinal), spin-spin (transverse), and dipolar relaxations were measured. As expected, the different samples studied had strikingly different NMR properties. These results have been extended to look for pH-sensitive changes in the NMR properties of calcium pectate gels and bean cell walls, since both show marked pH-sensitive changes in their rheological behavior. Pulsed field gradient NMR studies of very mobile components of polysaccharide systems are discussed.

  4. Bile acids conjugation in human bile is not random: new insights from (1)H-NMR spectroscopy at 800 MHz.

    PubMed

    Nagana Gowda, G A; Shanaiah, Narasimhamurthy; Cooper, Amanda; Maluccio, Mary; Raftery, Daniel

    2009-06-01

    Bile acids constitute a group of structurally closely related molecules and represent the most abundant constituents of human bile. Investigations of bile acids have garnered increased interest owing to their recently discovered additional biological functions including their role as signaling molecules that govern glucose, fat and energy metabolism. Recent NMR methodological developments have enabled single-step analysis of several highly abundant and common glycine- and taurine- conjugated bile acids, such as glycocholic acid, glycodeoxycholic acid, glycochenodeoxycholic acid, taurocholic acid, taurodeoxycholic acid, and taurochenodeoxycholic acid. Investigation of these conjugated bile acids in human bile employing high field (800 MHz) (1)H-NMR spectroscopy reveals that the ratios between two glycine-conjugated bile acids and their taurine counterparts correlate positively (R2 = 0.83-0.97; p = 0.001 x 10(-2)-0.006 x 10(-7)) as do the ratios between a glycine-conjugated bile acid and its taurine counterpart (R2 = 0.92-0.95; p = 0.004 x 10(-3)-0.002 x 10(-10)). Using such correlations, concentration of individual bile acids in each sample could be predicted in good agreement with the experimentally determined values. These insights into the pattern of bile acid conjugation in human bile between glycine and taurine promise useful clues to the mechanism of bile acids' biosynthesis, conjugation and enterohepatic circulation, and may improve our understanding of the role of individual conjugated bile acids in health and disease. PMID:19373503

  5. Gender-Specific Metabolomic Profiling of Obesity in Leptin-Deficient ob/ob Mice by 1H NMR Spectroscopy

    PubMed Central

    Kim, Sang-Woo; Jung, Youngae; Bae, Hyun-Whee; Lee, Daeyoup; Park, Sung Goo; Lee, Chul-Ho; Hwang, Geum-Sook; Chi, Seung-Wook

    2013-01-01

    Despite the numerous metabolic studies on obesity, gender bias in obesity has rarely been investigated. Here, we report the metabolomic analysis of obesity by using leptin-deficient ob/ob mice based on the gender. Metabolomic analyses of urine and serum from ob/ob mice compared with those from C57BL/6J lean mice, based on the 1H NMR spectroscopy in combination with multivariate statistical analysis, revealed clear metabolic differences between obese and lean mice. We also identified 48 urine and 22 serum metabolites that were statistically significantly altered in obese mice compared to lean controls. These metabolites are involved in amino acid metabolism (leucine, alanine, ariginine, lysine, and methionine), tricarbocylic acid cycle and glucose metabolism (pyruvate, citrate, glycolate, acetoacetate, and acetone), lipid metabolism (cholesterol and carnitine), creatine metabolism (creatine and creatinine), and gut-microbiome-derived metabolism (choline, TMAO, hippurate, p-cresol, isobutyrate, 2-hydroxyisobutyrate, methylamine, and trigonelline). Notably, our metabolomic studies showed distinct gender variations. The obese male mice metabolism was specifically associated with insulin signaling, whereas the obese female mice metabolism was associated with lipid metabolism. Taken together, our study identifies the biomarker signature for obesity in ob/ob mice and provides biochemical insights into the metabolic alteration in obesity based on gender. PMID:24098417

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

    PubMed Central

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

    2004-01-01

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

  7. (1) H NMR spectroscopy of glioblastoma stem-like cells identifies alpha-aminoadipate as a marker of tumor aggressiveness.

    PubMed

    Rosi, Antonella; Ricci-Vitiani, Lucia; Biffoni, Mauro; Grande, Sveva; Luciani, Anna Maria; Palma, Alessandra; Runci, Daniele; Cappellari, Marianna; De Maria, Ruggero; Guidoni, Laura; Pallini, Roberto; Viti, Vincenza

    2015-03-01

    Patients suffering from glioblastoma multiforme (GBM) face a poor prognosis with median survival of about 14 months. High recurrence rate and failure of conventional treatments are attributed to the presence of GBM cells with stem-like properties (GSCs). Metabolite profiles of 42 GSC lines established from the tumor tissue of adult GBM patients were screened with (1) H NMR spectroscopy and compared with human neural progenitor cells from human adult olfactory bulb (OB-NPCs) and from the developing human brain (HNPCs). A first subset (n=12) of GSCs exhibited a dramatic accumulation of the metabolite α-aminoadipate (αAAD), product of the oxidation of α-aminoadipic semialdehyde catalyzed by the ALDH7A1 aldehyde dehydrogenase (ALDH) family in lysine catabolism. αAAD was low/not detectable in a second GSC subset (n=13) with the same neural metabolic profile as well as in a third GSC subset (n=17) characterized by intense lipid signals. Likewise, αAAD was not detected in the spectra of OB-NPCs or HNPCs. Inhibition of mitochondrial ATP synthase by oligomycin treatment revealed that the lysine degradative pathway leading to αAAD formation proceeds through saccharopine, as usually observed in developing brain. Survival curves indicated that high αAAD levels in GSCs significantly correlated with poor patient survival, similarly to prostate and non-small-cell-lung cancers, where activity of ALDH7A1 correlates with tumor aggressiveness. PMID:25581615

  8. sup 1 H NMR study of renal trimethylamine responses to dehydration and acute volume loading in man

    SciTech Connect

    Avison, M.J.; Rothman, D.L.; Nixon, T.W.; Long, W.S.; Siegel, N.J. )

    1991-07-15

    The authors have used volume-localized {sup 1}H NMR spectroscopy to detect and measure changes in medullary trimethylamines (TMAs) in the human kidney in vivo. Localized water-suppressed {sup 1}H spectra were collected from a volume of interest located within the renal medulla by using a stimulated echo-based localization scheme. The principal resonances in the medullary {sup 1}H spectrum were residual water, lipid, and TMAs. The TMA line width was 7-15 Hz before filtering, and the signal-to-noise ratio was 40:1. In four normal volunteers, 15 hr of dehydration led to a significant increase in urine ismolality and decrease in body weight and an increase in medullary TMAs. A subsequent water load caused a transient water diuresis, a return to euvolemic body weight, and a significant reduction in medullary TMAs within 4 hr. These results suggest that TMAs may play an osmoregulatory role in the medulla of the normal human kidney.

  9. Identification and quantification of major steviol glycosides in Stevia rebaudiana purified extracts by 1H NMR spectroscopy.

    PubMed

    Pieri, Valerio; Belancic, Andrea; Morales, Susana; Stuppner, Hermann

    2011-05-11

    The use of (1)H NMR spectroscopy for the characterization of Stevia rebaudiana extracts is presented. The developed method allows qualitative and quantitative determination of the major steviol glycosides in purified extracts and fractions obtained from various stages of the purification process. Moreover, it proved to be a powerful tool to differentiate between glycosides which are naturally occurring in the stevia plant and artifacts formed in the course of the manufacturing process. Identification of steviol glycosides was achieved by the use of 2D NMR techniques, whereas quantification is based on qHNMR using anthracene as internal standard. The solvent mixture pyridine-d(5)-DMSO-d(6) (6:1) enabled satisfactory separation of the signals to be integrated. Validation of the method was performed in terms of specificity, precision, accuracy, linearity, robustness, and stability. Quantitative results were compared to those obtained with the JECFA HPLC-UV method and were found to be in reasonable agreement. NMR analysis does not rely on the use of reference compounds and enables significantly faster analysis compared to HPLC-UV. Thus, NMR represents a feasible alternative to HPLC-based methods for the quality control of Stevia rebaudiana extracts. PMID:21417451

  10. Characterization of tea cultivated at four different altitudes using 1H NMR analysis coupled with multivariate statistics.

    PubMed

    Ohno, Akiko; Oka, Kitaro; Sakuma, Chiseko; Okuda, Haruhiro; Fukuhara, Kiyoshi

    2011-05-25

    The taste of black tea differs according to the different areas in which the tea is grown, even for the same species of tea. A combination of (1)H NMR spectroscopy and partial least-squares discriminate analysis (PLS-DA) was used to assess the quality differences of tea leaves from four cultivation areas with different elevations, RAN > 1800 m, UDA = 1200 m, MEDA = 600 m, and YATA < 300 m, in Sri Lanka. As a result of a statistical analysis, PLS-DA showed a separation between high- and low-quality black teas derived from the four different tea cultivation areas. RAN from the highest elevation showed characteristic trends in the levels of theaflavin and theaflavin 3,3'-digallate that were found only in RAN, and the levels of theanine and caffeine were higher, and the levels of thearubigins, especially thearubigin 3,3'-digallate, were lower in RAN than in UDA, MEDA, and YATA. The structures of these components were determined by 1D and 2D NMR analyses. These results demonstrate that this method can be used to evaluate black tea quality according to the chemical composition or metabolites, which are characteristic of the tea leaves cultivated in four regions with different elevations in Sri Lanka. PMID:21456619

  11. Understanding the electronic properties of the CuA site from the soluble domain of cytochrome c oxidase through paramagnetic 1H NMR.

    PubMed

    Salgado, J; Warmerdam, G; Bubacco, L; Canters, G W

    1998-05-19

    The soluble domain of the subunit II of cytochrome c oxidase from Paracoccus versutus was cloned, expressed, and studied by 1H NMR at 600 MHz. The properties of the redox-active dinuclear CuA site in the paramagnetic mixed-valence Cu(I)-Cu(II) state were investigated in detail. A group of relatively sharp signals found between 30 and 15 ppm in the 1H NMR spectrum correspond to the imidazole protons of the coordinated histidines (H181 and H224). A second group of broader and farther shifted signals between 50 and 300 ppm are assigned to Hbeta protons of the bridging cysteines (C216 and C220); the protons from the weak M227 and E218 ligands do not shift outside of the diamagnetic envelope. About 40% of the total spin density appears delocalized over the cysteine-bridging ligands while a much smaller amount is delocalized on the two ligand histidines. The latter have similar spin density distributions. Analysis of the pattern of the hyperfine shifts of the Cys H beta protons shows that the ground state bears 2B3u character, in which the sulfur lobes in the singly occupied molecular orbital are aligned with the Cu-Cu axis. Analysis of the temperature dependence of the shifts of the Cys H beta signals leads to the conclusion that the 2B2u excited state is thermally accessible at room temperature (Delta E approximately kT). PMID:9585552

  12. Are nucleus-independent (NICS) and 1H NMR chemical shifts good indicators of aromaticity in π-stacked polyfluorenes?

    NASA Astrophysics Data System (ADS)

    Osuna, Sílvia; Poater, Jordi; Bofill, Josep M.; Alemany, Pere; Solà, Miquel

    2006-09-01

    We have analyzed the change of local aromaticity in a series of polyfluorene compounds with the increase of the number of π-stacked layers. The local aromaticity of the aromatic and non-aromatic rings of polyfluorenes remains unchanged when going from one to four layers of π-stacked rings according to HOMA, PDI, and FLU aromaticity descriptors. On the contrary, experimental 1H NMR chemical shifts indicate a reduction of the aromaticity of π-stacked rings with the increase of the number of layers. Calculated NICS also show a change of aromaticity, but opposite to the tendency given by the 1H NMR chemical shifts. We show that this increase (decrease) of local aromaticity in superimposed aromatic rings indicated by NICS ( 1H NMR) is not real but the result of the coupling between the magnetic fields generated by the π-stacked rings.

  13. Fatty acids profile of Sacha Inchi oil and blends by 1H NMR and GC-FID.

    PubMed

    Vicente, Juarez; de Carvalho, Mario Geraldo; Garcia-Rojas, Edwin E

    2015-08-15

    This study aimed at the characterization of blends of Sacha Inchi oil (SIO) with different ratios of SO (soybean oil) and CO (corn oil) by nuclear magnetic resonance ((1)H NMR), compared with the data obtained by gas chromatography with a flame ionization detector (GC-FID). The (1)H NMR and GC-FID data from different ratios of SIO were adjusted by a second order polynomial equation. The two techniques were highly correlated (R(2) values ranged from 0.995 to 0.999), revealing that (1)H NMR is an efficient methodology for the quantification of omega-3 fatty acids in oils rich in omega-6 fatty acids or vice versa such as SO and CO and, on the other hand, can be used to quantify ω-6 in oils rich in ω-3, such as SIO. PMID:25794742

  14. High-resolution (1)H NMR investigations of the capacity of dentifrices containing a "smart" bioactive glass to influence the metabolic profile of and deliver calcium ions to human saliva.

    PubMed

    Grootveld, Martin; Silwood, Christopher J L; Winter, Walter T

    2009-10-01

    Dentifrices containing H(2)O-reactive bioactive glasses alleviate hypersensitivity in teeth via the blockage of open dentinal tubules. Here, the ability of two such products to release Ca(2+) ions into human saliva was investigated, together with their influence on the status of this biofluid's (1)H NMR-detectable biomolecules. Human salivary supernatants were equilibrated with increasing volumes of those derived from each dentifrice (5.00 min at 37 degrees C). These biofluids were also equilibrated at 37 degrees C with a preselected quantity of the intact products (samples were collected at increasing timepoints). Salivary Ca(2+) concentrations were monitored by a (1)H NMR technique involving ethylenediamine tetra-acetate addition and/or atomic absorption spectrometry. Added Ca(2+)- and dentifrice supernatant volume (DSV)-induced modifications to the salivary (1)H NMR profile were explored by spectral titration. Data acquired demonstrated added DSV-dependent increases in salivary Ca(2+) concentrations and (Ca(2+)-independent) modifications to the intensities of selected salivary (1)H NMR signals, particularly those of the malodorous amines methyl-, dimethyl-, and trimethylamines, which were diminished by up to 80% of their prior values. Time-dependent elevations in salivary Ca(2+) level were observed on equilibration with the intact dentifrices. Added Ca(2+) ions exerted a concentration-dependent influence on a range of resonances (including those of citrate, succinate, pyruvate, and lactate). These data provide valuable information regarding the mechanisms of action of the products tested. PMID:19388087

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

    SciTech Connect

    Fischer, D.

    1990-09-21

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

  16. 1H NMR studies of insulin: histidine residues, metal binding, and dissociation in alkaline solution.

    PubMed

    Ramesh, V; Bradbury, J H

    1987-10-01

    The shifts of the H2 histidine B5 and B10 resonances of 2-Zn insulin hexamer were followed in 2H2O by 1H NMR spectroscopy at 270 MHz from pH 9.85 to 7. The two resonances present at high pH, previously assigned to H2 histidine B5 and B10 residues, moved slightly downfield and split into four resonances at pH 8.95 and also at pH 7. By use of a paramagnetic broadening probe (Mn2+) and the addition of Zn2+ to metal-free insulin, it was deduced that the four resonances arose from histidines B10 and B5 in two different magnetic environments, probably either bound to Zn2+ or not bound to Zn2+. The pK' values of the B5 and B10 histidines were determined in 60% 2H2O-40% dioxan, in which insulin was soluble throughout the pH range, to be 7.1 and 6.8, respectively at 37 degrees C. Studies at higher pH indicated that at a concentration level suitable for 1H NMR (approximately 1 mM) at 37 degrees C in 2H2O the 2-Zn hexamer was largely dissociated to dimer at pH 10.3 and to monomer at pH 10.8. Addition of paramagnetic shift probe Ni2+ to metal-free insulin caused changes to the spectrum similar to those produced on addition of diamagnetic Zn2+. Addition of Co2+ gave a different result, but there was no paramagnetic shift of the H2 histidine B10 resonance, probably because of rapid exchange at the binding site. Addition of Cd2+ and of Cd2+ and Ca2+ produced changes that were similar to each other but were different from those observed on addition of Zn2+, probably due to the binding of Cd2+ and Ca2+ at glutamate B13. PMID:3310894

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

    SciTech Connect

    Ramesh, V.; Bradbury, J.H.

    1987-10-01

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

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

    PubMed

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

    2015-10-14

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

  19. Quantitative (1)H NMR method for hydrolytic kinetic investigation of salvianolic acid B.

    PubMed

    Pan, Jianyang; Gong, Xingchu; Qu, Haibin

    2013-11-01

    This work presents an exploratory study for monitoring the hydrolytic process of salvianolic acid B (Sal B) in low oxygen condition using a simple quantitative (1)H NMR (Q-NMR) method. The quantity of the compounds was calculated by the relative ratio of the integral values of the target peak for each compound to the known amount of the internal standard trimethylsilyl propionic acid (TSP). Kinetic runs have been carried out on different initial concentrations of Sal B (5.00, 10.0, 20.0mg/mL) and temperatures of 70, 80, 90°C. The effect of these two factors during the transformation process of Sal B was investigated. The hydrolysis followed pseudo-first-order kinetics and the apparent degradation kinetic constant at 80°C decreased when concentration of Sal B increased. Under the given conditions, the rate constant of overall hydrolysis as a function of temperature obeyed the Arrhenius equation. Six degradation products were identified by NMR and mass spectrometric analysis. Four of these degradation products, i.e. danshensu (DSS), protocatechuic aldehyde (PRO), salvianolic acid D (Sal D) and lithospermic acid (LA) were further identified by comparing the retention times with standard compounds. The advantage of this Q-NMR method was that no reference compounds were required for calibration curves, the quantification could be directly realized on hydrolyzed samples. It was proved to be simple, convenient and accurate for hydrolytic kinetic study of Sal B. PMID:23867115

  20. Secondary structure determination of human. beta. -endorphin by /sup 1/H NMR spectroscopy

    SciTech Connect

    Lichtarge, O.; Jardetzky, O.; Li, C.H.

    1987-09-08

    The /sup 1/H NMR spectra of human ..beta..-endorphin indicate that the peptide exists in random-coil form in aqueous solution but becomes helical in mixed solvent. Thermal denaturation NMR experiments show that in water there is no transition between 24 and 75/sup 0/C, while a slow noncooperative thermal unfolding is observed in a 60% methanol-40% water mixed solvent in the same temperature range. These findings are consistent with circular dichroism studies by other workers concluding that ..beta..-endorphin is a random coil in water but that it forms 50% ..cap alpha..-helix or more in mixed solvents. The peptide in the mixed water-methanol solvent was further studied by correlated spectroscopy (COSY) and nuclear Overhauser effect spectroscopy (NOESY) experiments. These allow a complete set of assignments to be made and establish two distinct stretches over which the solvent induces formation of ..cap alpha..-helices: the first occurs between Tyr-1 and Thr-12 and the second between Leu-14 and extending to Lys-28. There is evidence that the latter is capped by a turn occurring between Lys-28 and Glu-31. These helices form at the enkephalin receptor binding site, which is at the amino terminus, and at the morphine receptor binding site, located at the carboxyl terminus. The findings suggest that these two receptors may specifically recognize ..cap alpha..-helices.

  1. Resolution Improvements in in Vivo1H NMR Spectra with Increased Magnetic Field Strength

    NASA Astrophysics Data System (ADS)

    Gruetter, Rolf; Weisdorf, Sally A.; Rajanayagan, Vasantham; Terpstra, Melissa; Merkle, Hellmut; Truwit, Charles L.; Garwood, Michael; Nyberg, Scott L.; Ugurbil, Kâmil

    1998-11-01

    The measurement of cerebral metabolites using highly homologous localization techniques and similar shimming methods was performed in the human brain at 1.5 and 4 T as well as in the dog and rat brain at 9.4 T. In rat brain, improved resolution was achieved by shimming all first- and second-order shim coils using a fully adiabatic FASTMAP sequence. The spectra showed a clear improvement in spectral resolution for all metabolite resonances with increased field strength. Changes in cerebral glutamine content were clearly observed at 4 T compared to 1.5 T in patients with hepatic encephalopathy. At 9.4 T, glutamine H4 at 2.46 ppm was fully resolved from glutamate H4 at 2.37 ppm, as was the potential resonance from γ-amino-butyric acid at 2.30 ppm and N-acetyl-aspartyl-glutamate at 2.05 ppm. Singlet linewidths were found to be as low as 6 Hz (0.015 ppm) at 9.4 T, indicating a substantial decrease in ppm linewidth with field strength. Furthermore, the methylene peak of creatine was partially resolved from phosphocreatine, indicating a close to 1:1 relationship in gray matter. We conclude that increasing the magnetic field strength increases spectral resolution also for1H NMR, which can lead to more than linear sensitivity gains.

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

    NASA Astrophysics Data System (ADS)

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

    1999-10-01

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

  3. Relaxation of water protons in highly concentrated aqueous protein systems studied by 1H NMR spectroscopy.

    PubMed

    Szuminska, K; Gutsze, A; Kowalczyk, A

    2001-01-01

    Concentrated Aqueous Protein Systems, Proton Relaxation Times, Slow Chemical Exchange In this paper we present proton spin-lattice (T1) and spin-spin (T2) relaxation times measured vs. concentration, temperature, pulse interval (tauCPMG) as well as 1H NMR spectral measurements in a wide range of concentrations of bovine serum albumin (BSA) solutions. The anomalous relaxation behaviour of the water protons, similar to that observed in mammalian lenses, was found in the two most concentrated solutions (44% and 46%). The functional dependence of the spin-spin relaxation time vs. tauCPMG pulse interval and the values of the motional activation parameters obtained from the temperature dependencies of spin-lattice relaxation times suggest that the water molecule mobility is reduced in these systems. The slow exchange process on the T2 time scale is proposed to explain the obtained data. The proton spectral measurements support the hypothesis of a slow exchange mechanism in the highest concentrated solutions. From the analysis of the shape of the proton spectra the mean exchange times between bound and bulk water proton groups (tauex) have been estimated for the range of the highest concentrations (30%-46%). The obtained values are of the order of milliseconds assuring that the slow exchange condition is fulfilled in the most concentrated samples. PMID:11837660

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

    PubMed

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

    2010-10-13

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

  5. 1H NMR global metabolic phenotyping of acute pancreatitis in the emergency unit.

    PubMed

    Villaseñor, Alma; Kinross, James M; Li, Jia V; Penney, Nicholas; Barton, Richard H; Nicholson, Jeremy K; Darzi, Ara; Barbas, Coral; Holmes, Elaine

    2014-12-01

    We have investigated the urinary and plasma metabolic phenotype of acute pancreatitis (AP) patients presenting to the emergency room at a single center London teaching hospital with acute abdominal pain using (1)H NMR spectroscopy and multivariate modeling. Patients were allocated to either the AP (n = 15) or non-AP patients group (all other causes of abdominal pain, n = 21) on the basis of the national guidelines. Patients were assessed for three clinical outcomes: (1) diagnosis of AP, (2) etiology of AP caused by alcohol consumption and cholelithiasis, and (3) AP severity based on the Glasgow score. Samples from AP patients were characterized by high levels of urinary ketone bodies, glucose, plasma choline and lipid, and relatively low levels of urinary hippurate, creatine and plasma-branched chain amino acids. AP could be reliably identified with a high degree of sensitivity and specificity (OPLS-DA model R(2) = 0.76 and Q(2)Y = 0.59) using panel of discriminatory biomarkers consisting of guanine, hippurate and creatine (urine), and valine, alanine and lipoproteins (plasma). Metabolic phenotyping was also able to distinguish between cholelithiasis and colonic inflammation among the heterogeneous non-AP group. This work has demonstrated that combinatorial biomarkers have a strong diagnostic and prognostic potential in AP with relevance to clinical decision making in the emergency unit. PMID:25160714

  6. Methodology of 1H NMR Spectroscopy of the Human Brain at Very High Magnetic Fields

    PubMed Central

    Tkáč, I.; Gruetter, R.

    2009-01-01

    An ultrashort-echo-time stimulated echo-acquisition mode (STEAM) pulse sequence with interleaved outer volume suppression and VAPOR (variable power and optimized relaxation delays) water suppression was redesigned and optimized for human applications at 4 and 7 T, taking into account the specific requirements for spectroscopy at high magnetic fields and limitations of currently available hardware. In combination with automatic shimming, automated parameter adjustments and data processing, this method provided a user-friendly tool for routine 1H nuclear magnetic resonance (NMR) spectroscopy of the human brain at very high magnetic fields. Effects of first- and second-order shimming, single-scan averaging, frequency and phase corrections, and eddy currents were described. LCModel analysis of an in vivo 1H NMR spectrum measured from the human brain at 7 T allowed reliable quantification of more than fifteen metabolites noninvasively, illustrating the potential of high-field NMR spectroscopy. Examples of spectroscopic studies performed at 4 and 7 T demonstrated the high reproducibility of acquired spectra quality. PMID:20179773

  7. 1H NMR Spectroscopy and MVA Analysis of Diplodus sargus Eating the Exotic Pest Caulerpa cylindracea

    PubMed Central

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

    2015-01-01

    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. PMID:26058009

  8. Broad identification of bacterial type in urinary tract infection using (1)h NMR spectroscopy.

    PubMed

    Gupta, Ashish; Dwivedi, Mayank; Mahdi, Abbas Ali; Khetrapal, Chunni Lal; Bhandari, Mahendra

    2012-03-01

    To address the shortcomings of urine culture for the rapid identification of urinary tract infection (UTI), we applied (1)H-nuclear magnetic resonance (NMR) spectroscopy as a surrogate method for fast screening of microorganisms. Study includes 682 urine samples from suspected UTI patients, 50 healthy volunteers, and commercially available standard strains of gram negative bacilli (GNB) (Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumonia, Enterobacter, Acinetobacter, Proteus mirabilis, Citrobacter frundii) and gram positive cocci (GPC) (Enterococcus faecalis, Streptococcus group B, Staphylococcus saprophyticus). Acetate, lactate, ethanol, succinate, creatinine, trimethylamine (TMA), citrate, trimethylamin-N-oxide, glycine, urea, and hippurate were measured by (1)H NMR spectroscopy. All urine specimens were evaluated with culture method. Multivariate discriminant function analysis (DFA) reveals that acetate, lactate, succinate, and formate were able to differentiate, with high accuracy (99.5%), healthy controls from UTI patients. This statistical analysis was also able to classify GNB to GPC infected urine samples with high accuracy (96%). This technique appears to be a promising, rapid, and noninvasive approach to probing GNB and GPC infected urine specimens with its distinguishing metabolic profile. The determination of infection will be very important for rapidly and efficiently measuring the efficacy of a tailored treatment, leading to prompt and appropriate care of UTI patients. PMID:22292465

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

    NASA Astrophysics Data System (ADS)

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

    2011-05-01

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

  10. 1H NMR-based metabolic profiling for evaluating poppy seed rancidity and brewing.

    PubMed

    Jawień, Ewa; Ząbek, Adam; Deja, Stanisław; Łukaszewicz, Marcin; Młynarz, Piotr

    2015-12-01

    Poppy seeds are widely used in household and commercial confectionery. The aim of this study was to demonstrate the application of metabolic profiling for industrial monitoring of the molecular changes which occur during minced poppy seed rancidity and brewing processes performed on raw seeds. Both forms of poppy seeds were obtained from a confectionery company. Proton nuclear magnetic resonance (1H NMR) was applied as the analytical method of choice together with multivariate statistical data analysis. Metabolic fingerprinting was applied as a bioprocess control tool to monitor rancidity with the trajectory of change and brewing progressions. Low molecular weight compounds were found to be statistically significant biomarkers of these bioprocesses. Changes in concentrations of chemical compounds were explained relative to the biochemical processes and external conditions. The obtained results provide valuable and comprehensive information to gain a better understanding of the biology of rancidity and brewing processes, while demonstrating the potential for applying NMR spectroscopy combined with multivariate data analysis tools for quality control in food industries involved in the processing of oilseeds. This precious and versatile information gives a better understanding of the biology of these processes. PMID:26540222

  11. Wastewater Colloidal Organic Carbon: Characterization of Filtration Fractions Using 1H NMR.

    PubMed

    McPhedran, Kerry N; Seth, Rajesh

    2016-04-01

    The current study separates colloidal organic carbon (COC) of municipal wastewater using membrane and ultrafiltration filters followed by characterization using 1H nuclear magnetic resonance (NMR) and UV absorbance with the goal of determination of size-specific characteristics, which may be used to correlate contaminant partitioning to natural COC. Passing fractions included 49.7, 44.8, 39.3, and 33.1 mg/L COC for filter sizes 1.5 μm, 0.45 μm, 100 kDa, and 1 kDa, respectively. The methodology used for processing COC prior to 1H NMR characterization was novel and successful in concentrating COC without modification of structures, which is the general drawback of other separation techniques such as resin extractions. This concentration technique is quite simple (i.e., not dependent on specialized instrumentation) and allows much shorter NMR experimental durations saving time and cost of analysis. Further work using NMR techniques will allow for greater understanding of COC molecular characteristics and be valuable for use in predictive modeling improvements. PMID:27131054

  12. Intra- and extracellular carbohydrates in plant cell cultures investigated by (1)H-NMR.

    PubMed

    Schripsema, J; Erkelens, C; Verpoorte, R

    1991-01-01

    With the aim of quantifying intra- and extracellular carbohydrates media and cell-extracts from a Tabernaemontana divaricata plant cell-suspension culture were investigated with (1)H-NMR.For suppression of the solvent peak the Meiboom-Gill modification of the Carr-Purcell (CPMG) spin-echo sequence was used after addition of a paramagnetic relaxation agent (Mn(2+)) to the sample. Several aspects of this method were optimized (the manganese concentration, the interpulse delay and the number of spin-echo cycles) so as to obtain a rapid and easy method in which no pretreatment of media or cell-extracts was needed. Besides the speed and ease of the method, also the direct identification of carbohydrates and other main components is an advantage.The exhaustion of extracellular carbohydrates was found to coincide with the maximum amount of intracellular carbohydrates. The intracellular carbohydrates, i.e. glucose and fructose, were consumed at a low rate, during several weeks. PMID:24213796

  13. Relativistic force field: parametric computations of proton-proton coupling constants in (1)H NMR spectra.

    PubMed

    Kutateladze, Andrei G; Mukhina, Olga A

    2014-09-01

    Spin-spin coupling constants in (1)H NMR carry a wealth of structural information and offer a powerful tool for deciphering molecular structures. However, accurate ab initio or DFT calculations of spin-spin coupling constants have been very challenging and expensive. Scaling of (easy) Fermi contacts, fc, especially in the context of recent findings by Bally and Rablen (Bally, T.; Rablen, P. R. J. Org. Chem. 2011, 76, 4818), offers a framework for achieving practical evaluation of spin-spin coupling constants. We report a faster and more precise parametrization approach utilizing a new basis set for hydrogen atoms optimized in conjunction with (i) inexpensive B3LYP/6-31G(d) molecular geometries, (ii) inexpensive 4-31G basis set for carbon atoms in fc calculations, and (iii) individual parametrization for different atom types/hybridizations, not unlike a force field in molecular mechanics, but designed for the fc's. With the training set of 608 experimental constants we achieved rmsd <0.19 Hz. The methodology performs very well as we illustrate with a set of complex organic natural products, including strychnine (rmsd 0.19 Hz), morphine (rmsd 0.24 Hz), etc. This precision is achieved with much shorter computational times: accurate spin-spin coupling constants for the two conformers of strychnine were computed in parallel on two 16-core nodes of a Linux cluster within 10 min. PMID:25158224

  14. Quantification of acesulfame potassium in processed foods by quantitative 1H NMR.

    PubMed

    Ohtsuki, Takashi; Sato, Kyoko; Abe, Yutaka; Sugimoto, Naoki; Akiyama, Hiroshi

    2015-01-01

    Acesulfame potassium (AceK), a high-intensity and non-caloric artificial sweetener, is used in various processed foods as a food additive. In this study, we established and validated a method for determining the AceK content in various processed foods by solvent extraction and quantitative (1)H NMR, using a certified reference material as the internal standard. In the recovery test, the proposed method gave satisfactory recoveries (88.4-99.6%) and repeatabilities (0.6-5.6%) for various processed foods. The limit of quantification was confirmed as 0.13 g kg(-1), which was sufficiently low for the purposes of monitoring AceK levels. In the analysis of commercially processed foods containing AceK, all AceK contents determined by the proposed method were in good agreement with those obtained by a conventional method based on dialysis and HPLC. Moreover, this method can achieve rapid quantification and yields analytical data with traceability to the International System of Units (SI) without the need for an authentic analyte standard. Therefore, the proposed method is a useful and practical tool for the determination of AceK in processed foods. PMID:25281163

  15. 1H NMR Spectroscopy and MVA Analysis of Diplodus sargus Eating the Exotic Pest Caulerpa cylindracea.

    PubMed

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

    2015-06-01

    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. PMID:26058009

  16. 1H-NMR metabolite profiles of different strains of Plasmodium falciparum.

    PubMed

    Teng, Rongwei; Lehane, Adele M; Winterberg, Markus; Shafik, Sarah H; Summers, Robert L; Martin, Rowena E; van Schalkwyk, Donelly A; Junankar, Pauline R; Kirk, Kiaran

    2014-01-01

    Although efforts to understand the basis for inter-strain phenotypic variation in the most virulent malaria species, Plasmodium falciparum, have benefited from advances in genomic technologies, there have to date been few metabolomic studies of this parasite. Using 1H-NMR spectroscopy, we have compared the metabolite profiles of red blood cells infected with different P. falciparum strains. These included both chloroquine-sensitive and chloroquine-resistant strains, as well as transfectant lines engineered to express different isoforms of the chloroquine-resistance-conferring pfcrt (P. falciparum chloroquine resistance transporter). Our analyses revealed strain-specific differences in a range of metabolites. There was marked variation in the levels of the membrane precursors choline and phosphocholine, with some strains having >30-fold higher choline levels and >5-fold higher phosphocholine levels than others. Chloroquine-resistant strains showed elevated levels of a number of amino acids relative to chloroquine-sensitive strains, including an approximately 2-fold increase in aspartate levels. The elevation in amino acid levels was attributable to mutations in pfcrt. Pfcrt-linked differences in amino acid abundance were confirmed using alternate extraction and detection (HPLC) methods. Mutations acquired to withstand chloroquine exposure therefore give rise to significant biochemical alterations in the parasite. PMID:25405893

  17. 15N and 1H NMR spectroscopy of the catalytic histidine in chloromethyl ketone-inhibited complexes of serine proteases.

    PubMed

    Tsilikounas, E; Rao, T; Gutheil, W G; Bachovchin, W W

    1996-02-20

    The hemiketal hydroxyl groups in chloromethyl ketone (cmk) complexes of trypsin and chymotrypsin have been reported to ionize to the oxyanion with pK(a) values 2-4 pK(a) units below expectations for such a functional group on the basis of the behavior of the hemiketal carbon atom in 13C NMR spectra [Finucane, M. D., & Malthouse, J. P. G. (1992) Biochem. J. 286, 889-900]. The low pK(a) indicates the enzymes selectively stabilize the oxyanion form of the bound inhibitor, and therefore that cmk complexes may be good models of enzyme-mediated transition-state stabilization. However, the 13C NMR studies could not rule out His57 as the titrating group. Here we report the behavior of the ring 15N atoms of His57 in the Ala-Ala-Pro-Val-cmk complex of alpha-lytic protease. Both N(delta 1) and N(epsilon 2) of His57 respond to an ionization with a pK(a) of approximately 7.5, but His57 itself does not titrate as N(epsilon 2) remains alkylated and N(delta 1) remains bonded to a proton over the entire pH range. The species titrating with a pK(a) of approximately 7.5 must therefore be the hemiketal hydroxyl. The results also show that the 1H NMR signal from the proton in the Asp-His hydrogen bond behaves in a characteristic manner in cmk complexes and can be used diagnostically to confirm that His57 does not titrate and to measure the pK(a) of the hemiketal hydroxyl in cmk-protease complexes without resorting to 15N-labeling. We have used the behavior of this signal to directly confirm that His57 does not titrate in the trypsin and chymotrypsin complexes that were the subjects of the original 13C NMR studies. PMID:8652587

  18. Antithrombin III and its interaction with heparin. Comparison of the human, bovine, and porcine proteins by /sup 1/H NMR spectroscopy

    SciTech Connect

    Gettins, P.

    1987-03-10

    /sup 1/H NMR has been used to characterize and compare the structures of antithrombin III from human, bovine, and porcine plasma as well as to investigate the interactions of each of these proteins with heparin fragments of defined length. The amino acid compositions of the three proteins are very similar, which is reflected in the gross features of their /sup 1/H NMR spectra. Human antithrombin III has five histidine residues, bovine has six, and porcine has five. The C(2) proton from each of these residues gives a narrow resonance and titrates with pH; the pK/sub a/'s are in the range 5.15-7.25. It is concluded that all histidines in each protein are surface residues with considerable independent mobility. The carbohydrate chains in each protein also give sharp resonances consistent with a surface location and motional flexibility. The /sup 1/H spectra are sensitive to heparin binding. Although heparin resonances obscure protein resonances in the region 3.2-6.0 ppm, difference spectra between antithrombin III with and without heparin show clear perturbation of a small number of aromatic and aliphatic protein protons. For human antithrombin III, it was shown that heparin fragments 8, 10, and 16 sugar residues in length result in almost identical perturbations to the protein. In contrast, tetrasaccharide results in fewer perturbations. Significantly, intact high molecular weight heparin causes the same spectral perturbations as the 16-residue fragment. These data are discussed in terms of requirements for heparin binding.

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

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

  20. Response to the Letter to the Editor regarding "Determination of the fatty acid profile by 1H-NMR spectroscopy."

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In expansion of previous work (G. Knothe, J.A. Kenar, Determination of the fatty acid profile by 1H-NMR spectroscopy, Eur. J. Lipid Sci. Technol. 2004, 106, 88-96), an additional approach is discussed for quantitating saturated fatty acids in the fatty acid profiles of common vegetable oils by 1H-NM...

  1. Application of (1)h NMR profiling to assess seed metabolomic diversity. A case study on a soybean era population.

    PubMed

    Harrigan, George G; Skogerson, Kirsten; MacIsaac, Susan; Bickel, Anna; Perez, Tim; Li, Xin

    2015-05-13

    (1)H NMR spectroscopy offers advantages in metabolite quantitation and platform robustness when applied in food metabolomics studies. This paper provides a (1)H NMR-based assessment of seed metabolomic diversity in conventional and glyphosate-resistant genetically modified (GM) soybean from a genetic lineage representing ∼35 years of breeding and differing yield potential. (1)H NMR profiling of harvested seed allowed quantitation of 27 metabolites, including free amino acids, sugars, and organic acids, as well as choline, O-acetylcholine, dimethylamine, trigonelline, and p-cresol. Data were analyzed by canonical discriminant analysis (CDA) and principal variance component analysis (PVCA). Results demonstrated that (1)H NMR spectroscopy was effective in highlighting variation in metabolite levels in the genetically diverse sample set presented. The results also confirmed that metabolite variability is influenced by selective breeding and environment, but not genetic modification. Therefore, metabolite variability is an integral part of crop improvement that has occurred for decades and is associated with a history of safe use. PMID:25940152

  2. Microscale Synthesis and (super 1)H NMR Analysis of Zn(super II) and Ni(super II) Tetraphenylporphyrins

    ERIC Educational Resources Information Center

    Saucedo, Laura; Mink, Larry M.

    2005-01-01

    A multisection undergraduate laboratory involving the microscale synthesis and spectroscopic analysis of unmetalled porphyrins and their corresponding metalloporphyins is described. The microscale synthesis involving the isolation of the metalloporphyrins as solids and their corresponding (super 1)H NMR spectra are presented.

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

    ERIC Educational Resources Information Center

    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…

  4. Combined (1)H NMR and LSER study for the compound-specific interactions between organic contaminants and organobentonites.

    PubMed

    Ruan, Xiuxiu; Zhu, Lizhong; Chen, Baoliang; Qian, Guangren; Frost, Ray L

    2015-12-15

    The compound-specific mechanisms for the sorption of organic contaminants onto cetyltrimethylammonium-saturated bentonite (i.e., CTMA-Bentonite) in water were evaluated by (1)H NMR study and Linear Solvation Energy Relationship (LSER) approach. In (1)H NMR study, comparing with pure CTMAB, the up-field shifts of hydrogen peaks for CH2N(+) and CH3N(+) of CTMA(+) in CTMAB-aromatics (1-naphtylamine, aniline and phenol) mixtures are much greater than that in CTMAB-aliphatics (cyclohexanone and cyclohexanol) mixtures. Meanwhile, the peak position of hydrogen on amino- and hydroxyl-groups of aromatic compounds also changes greatly. (1)H NMR data demonstrated the strong molecular interaction between the positive ammonium group of CTMA(+) and the delocalized π-systems of aromatic solutes, whereas the interactions of CTMA(+) with aliphatic compounds having electron-donating groups (such as cyclohexanol and cyclohexanone) or aromatic ring substituted by electron-withdrawing groups (i.e., nitrobenzene) or nonpolar aromatic compounds with single phenyl ring (i.e., toluene) are weak. The derived LSER equation was obtained by a multiple regression of the solid-water sorption coefficients (Kd) of 16 probe solutes upon their solvation parameters, and demonstrates aromatics sorption onto CTMA-Bentonite is concurrently governed by the π-/n-electron pair donor-accepter interaction and the cavity/dispersion interaction, while the predominant mechanism for aliphatic compounds is the cavity/dispersion interaction, consisting with the (1)H NMR results. PMID:26319328

  5. 1H NMR study of proton motion in hydrogen-bonded chain in Mannich base of 5,5'-dibromo-3-diethylaminomethyl-2,2'-biphenol

    NASA Astrophysics Data System (ADS)

    Wojciechowski, G.; Rozwadowski, Z.; Dziembowska, T.; Brzezinski, B.

    2001-01-01

    5,5'-dibromo-3-diethylaminomethyl-2,2'-biphenol was synthesized and the collective proton motion in two intramolecular hydrogen bonds was studied by 1H and 13C NMR as well as by FTIR spectroscopy in chloroform, acetonitrile and chloroform containing traces of water solutions. In dry chloroform, always, two separated proton signals for the two OH groups were observed. If traces of water were present at room temperature in the chloroform solution only one signal for the two OH protons was found. With decreasing temperature the collective proton motion, indicated by continuous absorption in the FTIR spectrum, was interrupted and two separate signals appeared in the 1H NMR spectrum. In acetonitrile the collective proton motion in the two intramolecular hydrogen-bonded system observed at room temperature vanished with decreasing temperature and finally only a cooperative hydrogen-bonded system, like in the solid state, was observed.

  6. Essential Parameters for Structural Analysis and Dereplication by 1H NMR Spectroscopy

    PubMed Central

    2015-01-01

    The present study demonstrates the importance of adequate precision when reporting the δ and J parameters of frequency domain 1H NMR (HNMR) data. Using a variety of structural classes (terpenoids, phenolics, alkaloids) from different taxa (plants, cyanobacteria), this study develops rationales that explain the importance of enhanced precision in NMR spectroscopic analysis and rationalizes the need for reporting Δδ and ΔJ values at the 0.1–1 ppb and 10 mHz level, respectively. Spectral simulations paired with iteration are shown to be essential tools for complete spectral interpretation, adequate precision, and unambiguous HNMR-driven dereplication and metabolomic analysis. The broader applicability of the recommendation relates to the physicochemical properties of hydrogen (1H) and its ubiquity in organic molecules, making HNMR spectra an integral component of structure elucidation and verification. Regardless of origin or molecular weight, the HNMR spectrum of a compound can be very complex and encode a wealth of structural information that is often obscured by limited spectral dispersion and the occurrence of higher order effects. This altogether limits spectral interpretation, confines decoding of the underlying spin parameters, and explains the major challenge associated with the translation of HNMR spectra into tabulated information. On the other hand, the reproducibility of the spectral data set of any (new) chemical entity is essential for its structure elucidation and subsequent dereplication. Handling and documenting HNMR data with adequate precision is critical for establishing unequivocal links between chemical structure, analytical data, metabolomes, and biological activity. Using the full potential of HNMR spectra will facilitate the general reproducibility for future studies of bioactive chemicals, especially of compounds obtained from the diversity of terrestrial and marine organisms. PMID:24895010

  7. Organic solute changes with acidification in Lake Skjervatjern as shown by 1H-NMR spectroscopy

    USGS Publications Warehouse

    Malcolm, R.L.; Hayes, T.

    1994-01-01

    1H-NMR spectroscopy has been found to be a useful tool to establish possible real differences and trends between all natural organic solute fractions (fulvic acids, humic acids, and XAD-4 acids) after acid-rain additions to the Lake Skjervatjern watershed. The proton NMR technique used in this study determined the spectral distribution of nonexchangeable protons among four peaks (aliphatic protons; aliphatic protons on carbon ?? or attached to electronegative groups; protons on carbons attached to O or N heteroatoms; and aromatic protons). Differences of 10% or more in the respective peak areas were considered to represent a real difference. After one year of acidification, fulvic acids decreased 13% (relative) in Peak 3 protons on carbon attached to N and O heteratoms and exhibited a decrease in aromatic protons between 27% and 31%. Humic acids also exhibited an 11% relative decrease in aromatic protons as a result of acidification. After one year of acidification, real changes were shown in three of the four proton assignments in XAD-4 acids. Peak 1 aliphatic protons increased by 14% (relative), Peak 3 protons on carbons attached to O and N heteroatoms decreased by 13% (relative), and aromatic protons (Peak 4) decreased by 35% (relative). Upon acidification, there was a trend in all solutes for aromatic protons to decrease and aliphatic protons to increase. The natural variation in organic solutes as shown in the Control Side B of the lake from 1990 to 1991 is perhaps a small limitation to the same data interpretations of acid rain changes at the Lake Skjervatjern site, but the proton NMR technique shows great promise as an independent scientific tool to detect and support other chemical techniques in establishing organic solute changes with different treatments (i.e., additions of acid rain).

  8. (1)H NMR based metabolomic profiling revealed doxorubicin-induced systematic alterations in a rat model.

    PubMed

    Niu, Qian-Yun; Li, Zhen-Yu; Du, Guan-Hua; Qin, Xue-Mei

    2016-01-25

    Doxorubicin (DOX) is used as a chemotherapy drug with severe carditoxicity. In this study, an integrated echocardiography along with pathological examination and (1)H NMR analysis of multiple biological matrices (urine, serum, heart, and kidney) was employed to systemically assess the toxicity of DOX. Echocardiographic results showed that impaired left ventricular contractility and degenerative pathology lesions in DOX group, which were in consistent with pathology. The endogenous metabolites in the urine, serum, heart and kidney was identified by comparison with the data from the literature and databases. Multivariate analysis, including PCA and OPLS, revealed 8 metabolites in urine, including succinate, 2-ketoglutarate, citrate, hippurate, methylamine, benzoate, allantion, and acetate were the potential changed biomarkers. In serum, perturbed metabolites include elevation of leucine, β-glucose, O-acetyl-glycoprotein, creatine, lysine, glycerin, dimethylglycine, trimethylamine-N-oxide, myo-inositol, and N-acetyl-glycoprotein, together with level decreases of acetone, lipid, lactate, glutamate, phosphocholine, acetoacetate and pyruvate. For heart, DOX exposure caused decline of lipid, lactate, leucine, alanine, glutamate, choline, xanthine, glycerin, carnitine, and fumarate, together with elevation of glutamine, creatine, inosine, taurine and malate. Metabolic changes of kidney were mainly involved in the accumulation of α-glucose, lactate, phosphocholine, betaine, threonine, choline, taurine, glycine, urea, hypoxanthine, glutamate, and nicotinamide, coupled with reduction of asparagine, valine, methionine, tyrosine, lysine, alanine, leucine, ornithine, creatine, lipid, and acetate. In addition, alterations of urinary metabolites exhibited a time-dependent manner. Complementary evidences by multiple matrices revealed disturbed pathways concerning energy metabolism, fatty acids oxidation, amino acids and purine metabolism, choline metabolism, and gut microbiota

  9. 1H NMR- based metabolomics approaches as non- invasive tools for diagnosis of endometriosis

    PubMed Central

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

    2016-01-01

    Background: So far, non-invasive diagnostic approaches such as ultrasound, magnetic resonance imaging, or blood tests do not have sufficient diagnostic power for endometriosis disease. Lack of a non-invasive diagnostic test contributes to the long delay between onset of symptoms and diagnosis of endometriosis. Objective: The present study focuses on the identification of predictive biomarkers in serum by pattern recognition techniques and uses partial least square discriminant analysis, multi-layer feed forward artificial neural networks (ANNs) and quadratic discriminant analysis (QDA) modeling tools for the early diagnosis of endometriosis in a minimally invasive manner by 1H- NMR based metabolomics. Materials and Methods: This prospective cohort study was done in Pasteur Institute, Iran in June 2013. Serum samples of 31 infertile women with endometriosis (stage II and III) who confirmed by diagnostic laparoscopy and 15 normal women were collected and analyzed by nuclear magnetic resonance spectroscopy. The model was built by using partial least square discriminant analysis, QDA, and ANNs to determine classifier metabolites for early prediction risk of disease. Results: The levels of 2- methoxyestron, 2-methoxy estradiol, dehydroepiandrostion androstendione, aldosterone, and deoxy corticosterone were enhanced significantly in infertile group. While cholesterol and primary bile acids levels were decreased. QDA model showed significant difference between two study groups. Positive and negative predict value levels obtained about 71% and 78%, respectively. ANNs provided also criteria for detection of endometriosis. Conclusion: The QDA and ANNs modeling can be used as computational tools in noninvasive diagnose of endometriosis. However, the model designed by QDA methods is more efficient compared to ANNs in diagnosis of endometriosis patients. PMID:27141542

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

    PubMed

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

    1991-12-01

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

  11. Essential parameters for structural analysis and dereplication by (1)H NMR spectroscopy.

    PubMed

    Pauli, Guido F; Chen, Shao-Nong; Lankin, David C; Bisson, Jonathan; Case, Ryan J; Chadwick, Lucas R; Gödecke, Tanja; Inui, Taichi; Krunic, Aleksej; Jaki, Birgit U; McAlpine, James B; Mo, Shunyan; Napolitano, José G; Orjala, Jimmy; Lehtivarjo, Juuso; Korhonen, Samuli-Petrus; Niemitz, Matthias

    2014-06-27

    The present study demonstrates the importance of adequate precision when reporting the δ and J parameters of frequency domain (1)H NMR (HNMR) data. Using a variety of structural classes (terpenoids, phenolics, alkaloids) from different taxa (plants, cyanobacteria), this study develops rationales that explain the importance of enhanced precision in NMR spectroscopic analysis and rationalizes the need for reporting Δδ and ΔJ values at the 0.1-1 ppb and 10 mHz level, respectively. Spectral simulations paired with iteration are shown to be essential tools for complete spectral interpretation, adequate precision, and unambiguous HNMR-driven dereplication and metabolomic analysis. The broader applicability of the recommendation relates to the physicochemical properties of hydrogen ((1)H) and its ubiquity in organic molecules, making HNMR spectra an integral component of structure elucidation and verification. Regardless of origin or molecular weight, the HNMR spectrum of a compound can be very complex and encode a wealth of structural information that is often obscured by limited spectral dispersion and the occurrence of higher order effects. This altogether limits spectral interpretation, confines decoding of the underlying spin parameters, and explains the major challenge associated with the translation of HNMR spectra into tabulated information. On the other hand, the reproducibility of the spectral data set of any (new) chemical entity is essential for its structure elucidation and subsequent dereplication. Handling and documenting HNMR data with adequate precision is critical for establishing unequivocal links between chemical structure, analytical data, metabolomes, and biological activity. Using the full potential of HNMR spectra will facilitate the general reproducibility for future studies of bioactive chemicals, especially of compounds obtained from the diversity of terrestrial and marine organisms. PMID:24895010

  12. High-field localized 1H NMR spectroscopy in the anesthetized and in the awake monkey.

    PubMed

    Pfeuffer, Josef; Juchem, Christoph; Merkle, Hellmut; Nauerth, Arno; Logothetis, Nikos K

    2004-12-01

    Localized cerebral in vivo 1H NMR spectroscopy (MRS) was performed in the anesthetized as well as the awake monkey using a novel vertical 7 T/60 cm MR system. The increased sensitivity and spectral dispersion gained at high field enabled the quantification of up to 16 metabolites in 0.1- to 1-ml volumes. Quantification was accomplished by using simulations of 18 metabolite spectra and a macromolecule (MM) background spectrum consisting of 12 components. Major cerebral metabolites (concentrations >3 mM) such as glutamate (Glu), N-acetylaspartate (NAA), creatine (Cr)/phosphocreatine (PCr) and myo-inositol (Ins) were identified with an error below 3%; most other metabolites were quantified with errors in the order of 10%. Metabolite ratios were 1.39:1 for total NAA, 1.38:1 for glutamate (Glu)/glutamine (Gln) and 0.09:1 for cholines (Cho) relative to total Cr. Taurine (Tau) was detectable at concentrations lower than 1 mM, while lactate (Lac) remained below the detection limit. The spectral dispersion was sufficient to separate metabolites of similar spectral patterns, such as Gln and Glu, N-acetylaspartylglutamate (NAAG) and NAA, and PCr-Cr. MRS in the awake monkey required the development and refinement of acquisition and correction strategies to minimize magnetic susceptibility artifacts induced by respiration and movement of the mouth or body. Periods with major motion artifacts were rejected, while a frequency/phase correction was performed on the remaining single spectra before averaging. In resting periods, both spectral amplitude and line width, that is, the voxel shim, were unaffected permitting reliable measurements. The corrected spectra obtained from the awake monkey afforded the reliable detection of 6-10 cerebral metabolites of 1-ml volumes. PMID:15707786

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

    PubMed

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

    2016-08-10

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

  14. (1)H NMR z-spectra of acetate methyl in stretched hydrogels: quantum-mechanical description and Markov chain Monte Carlo relaxation-parameter estimation.

    PubMed

    Shishmarev, Dmitry; Chapman, Bogdan E; Naumann, Christoph; Mamone, Salvatore; Kuchel, Philip W

    2015-01-01

    The (1)H NMR signal of the methyl group of sodium acetate is shown to be a triplet in the anisotropic environment of stretched gelatin gel. The multiplet structure of the signal is due to the intra-methyl residual dipolar couplings. The relaxation properties of the spin system were probed by recording steady-state irradiation envelopes ('z-spectra'). A quantum-mechanical model based on irreducible spherical tensors formed by the three magnetically equivalent spins of the methyl group was used to simulate and fit experimental z-spectra. The multiple parameter values of the relaxation model were estimated by using a Bayesian-based Markov chain Monte Carlo algorithm. PMID:25486634

  15. 1H NMR studies on the hydrogen-bonding network in mono-altro-beta-cyclodextrin and its complex with adamantane-1-carboxylic acid.

    PubMed

    Hakkarainen, Birgit; Fujita, Kahee; Immel, Stefan; Kenne, Lennart; Sandström, Corine

    2005-06-13

    The hydrogen-bond network in mono-altro-beta-cyclodextrin and in its inclusion complex with adamantane-1-carboxylic acid were investigated by (1)H NMR spectroscopy using the chemical shifts, temperature coefficients and vicinal coupling constants of the exchangeable hydroxy protons. The chemical shifts of the 3-OH signals indicated that the hydrogen-bond network between the 2-OH and 3-OH groups was disturbed not only on each side of the altrose residue, but also along the whole dextrin chain. Upon addition of adamantane-1-carboxylic acid, altrose underwent a conformational change from the (1)C(4) to the (O)S(2) form, allowing a more continuous belt of hydrogen bonding, as evidenced by the downfield shift experienced by the 3-OH proton signals of the glucose residues. PMID:15885670

  16. Study of inclusion complex between 2,6-dinitrobenzoic acid and β-cyclodextrin by 1H NMR, 2D 1H NMR (ROESY), FT-IR, XRD, SEM and photophysical methods.

    PubMed

    Srinivasan, Krishnan; Stalin, Thambusamy

    2014-09-15

    The formation of host-guest inclusion complex of 2,6-dinitrobenzoic acid (2,6-DNB) with nano-hydrophobic cavity of β-cyclodextrin (β-CD) in solution phase has been studied by UV-visible spectroscopy and electrochemical analysis (cyclic voltammetry, CV). The effect of acid-base concentrations of 2,6-DNB has been studied in presence and absence of β-CD to determination for the ground state acidity constant (pKa). The binding constant of inclusion complex at 303 K was calculated using Benesi-Hildebrand plot and thermodynamic parameter (ΔG) was also calculated. The solid inclusion complex formation between β-CD and 2,6-DNB was confirmed by 1H NMR, 2D 1H NMR (ROESY), FT-IR, XRD and SEM analysis. A schematic representation of this inclusion process was proposed by molecular docking studies using patch dock server. PMID:24769381

  17. Study of inclusion complex between 2,6-dinitrobenzoic acid and β-cyclodextrin by 1H NMR, 2D 1H NMR (ROESY), FT-IR, XRD, SEM and photophysical methods

    NASA Astrophysics Data System (ADS)

    Srinivasan, Krishnan; Stalin, Thambusamy

    2014-09-01

    The formation of host-guest inclusion complex of 2,6-dinitrobenzoic acid (2,6-DNB) with nano-hydrophobic cavity of β-cyclodextrin (β-CD) in solution phase has been studied by UV-visible spectroscopy and electrochemical analysis (cyclic voltammetry, CV). The effect of acid-base concentrations of 2,6-DNB has been studied in presence and absence of β-CD to determination for the ground state acidity constant (pKa). The binding constant of inclusion complex at 303 K was calculated using Benesi-Hildebrand plot and thermodynamic parameter (ΔG) was also calculated. The solid inclusion complex formation between β-CD and 2,6-DNB was confirmed by 1H NMR, 2D 1H NMR (ROESY), FT-IR, XRD and SEM analysis. A schematic representation of this inclusion process was proposed by molecular docking studies using patch dock server.

  18. FT-IR and {sup 1}H NMR characterization of the products of an ethylene inverse diffusion flame

    SciTech Connect

    Santamaria, Alexander; Mondragon, Fanor; Molina, Alejandro; Marsh, Nathan D.; Eddings, Eric G.; Sarofim, Adel F.

    2006-07-15

    Knowledge of the chemical structure of young soot and its precursors is very useful in the understanding of the paths leading to soot particle inception. This paper presents analyses of the chemical functional groups, based on FT-IR and {sup 1}H NMR spectroscopy of the products obtained in an ethylene inverse diffusion flame. The trends in the data indicate that the soluble fraction of the soot becomes progressively more aromatic and less aliphatic as the height above the burner increases. Results from {sup 1}H NMR spectra of the chloroform-soluble soot samples taken at different heights above the burner corroborate the infrared results based on proton chemical shifts (Ha, H{alpha}, H{beta}, and H{gamma}). The results indicate that the aliphatic {beta} and {gamma} hydrogens suffered the most drastic reduction, while the aromatic character increased considerably with height, particularly in the first half of the flame. (author)

  19. A study by (1)H NMR on the influence of some factors affecting lipid in vitro digestion.

    PubMed

    Nieva-Echevarría, Bárbara; Goicoechea, Encarnación; Manzanos, María J; Guillén, María D

    2016-11-15

    This article focuses on the impact of several experimental factors, including gastric acidification, intestinal transit time, presence of gastric lipase, sample/digestive fluids ratio, concentration and nature of the enzymes in intestinal juice, and bile concentration, on the extent of in vitro lipolysis when using a static model that simulates human digestion processes in mouth, stomach and small intestine. The study was carried out by Proton Nuclear Magnetic Resonance ((1)H NMR). This technique provides a complete molecular picture of lipolysis, evidencing for the first time, whether preferential hydrolysis of certain glycerides over others occurs. A lipolysis degree similar to that reported in vivo was reached by varying certain variables within a physiological range; among them, bile concentration was found to be crucial. The holistic view of this (1)H NMR study provides information of paramount importance to design sound in vitro digestion models to determine the bioaccessibility and bioavailability of lipophilic compounds. PMID:27283602

  20. Simultaneous detection of histamine release and lactate production in rat mast cells induced by compound 48/80 using sup 1 H NMR

    SciTech Connect

    Yoshizaki, Kazuo; Arizono, Naoki )

    1991-04-01

    {sup 1}H NMR spectroscopy was used to evaluate histamine release and lactate production in intact mast cells isolated from rats. The resonance lines of the aromatic histamine protons in mast cells, detected by the selective spin-excitation technique, were broader and located in a lower magnetic field than those in free histamine solution. When exocytosis of mast-cell granules was induced by compound 48/80, free histamine appeared, with a corresponding decrease in the amount of histamine in the mast cells; the lactate signal was also detected in the spectrum. On the addition of compound 48/ 80, there was a further release of histamine from mast cells, accompanied by further production of lactate. This result indicates that the mechanisms which induce the exocytosis of granules, and/or the events following exocytosis, activate glycolysis.

  1. 1H NMR detection of immobilized water molecules within a strong distal hydrogen-bonding network of substrate-bound human heme oxygenase-1.

    PubMed

    Syvitski, Ray T; Li, Yiming; Auclair, Karine; Ortiz De Montellano, Paul R; La Mar, Gerd N

    2002-12-01

    Solution 1H NMR is used to probe the environments of the donor protons of eight strong hydrogen bonds on the distal side of the heme substrate in the cyanide-inhibited, substrate-bound complex of human heme oxygenase, hHO. It is demonstrated that significant magnetization transfer from the bulk water signal to the eight labile protons does not result from chemical exchange, but from direct nuclear Overhauser effect due to the dipolar interaction of these labile protons with "ordered" water molecules. The enzyme labile proton to water proton distances are estimated at approximately 3 A. It is proposed that the role of the strong hydrogen-bonding network is to immobilize numerous water molecules which both stabilize the activated hydroperoxy species and funnel protons to the active site. PMID:12452690

  2. Determination of the time course of an enzymatic reaction by 1H NMR spectroscopy: hydroxynitrile lyase catalysed transhydrocyanation

    NASA Astrophysics Data System (ADS)

    Hickel, A.; Gradnig, G.; Griengl, H.; Schall, M.; Sterk, H.

    1996-01-01

    The time course of the enzyme catalysed transhydrocyanation of benzaldehyde to give ( S)-mandelonitrile was investigated using a hydroxynitrile lyase from Hevea brasiliensis as catalyst and acetone cyanohydrin as cyanide donor. Employing special techniques it was possible to apply 1H NMR spectroscopy in aqueous medium to monitor the concentration changes of all substrates and products. By this technique strong evidence for inhibition of the enzyme at higher substrate concentrations was obtained.

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

    PubMed

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

    2007-02-28

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

  4. Assessment of peeling of Astragalus roots using 1H NMR- and UPLC-MS-based metabolite profiling.

    PubMed

    Jung, Jee-Youn; Jung, Youngae; Kim, Jin-Sup; Ryu, Do Hyun; Hwang, Geum-Sook

    2013-10-30

    A metabolomic analysis was performed to examine the postharvest processing of Astragalus membranaceus roots with a focus on the peeling procedure using (1)H NMR and UPLC-MS analyses. Principal component analysis (PCA) score plots from the (1)H NMR and UPLC-MS data showed clear separation between peeled and unpeeled Astragalus roots. Peeled roots exhibited significant losses of several primary metabolites, including acetate, alanine, arginine, caprate, fumarate, glutamate, histidine, N-acetylaspartate, malate, proline, sucrose, trigonelline, and valine. In contrast, the peeled roots contained higher levels of asparagine, aspartate, and xylose, which are xylem-related compounds, and formate, which is produced in response to wound stress incurred during postharvest processing. In addition, the levels of isoflavonoids and astragalosides were significantly reduced in peeled Astragalus root. These results demonstrate that metabolite profiling based on a combination of (1)H NMR and UPLC-MS analyses can be used to evaluate peeling procedures used in the postharvest processing of herbal medicines. PMID:24073592

  5. Discrimination of Basal Cell Carcinoma from Normal Skin Tissue Using High-Resolution Magic Angle Spinning 1H NMR Spectroscopy

    PubMed Central

    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 1H NMR spectroscopy. HR-MAS 1H 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 < 0.05 were considered statistically significant. Univariate 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 1H NMR spectroscopy can be a valuable tool in the diagnosis of BCC. PMID:26934749

  6. Metabolomics-Based Study of Logarithmic and Stationary Phases of Promastigotes in Leishmania major by 1H NMR Spectroscopy

    PubMed Central

    Arjmand, Mohammad; Madrakian, Azadeh; Khalili, Ghader; Najafi, Ali; Zamani, Zahra; Akbari, Ziba

    2016-01-01

    Background: Cutaneous leishmaniasis is one of the most important parasitic diseases in humans. In this disease, one of the responsible organisms is Leishmania major, which is transmitted by sandfly vector. There are specific differences in biochemical profiles and metabolite pathways in logarithmic and stationary phases of Leishmania parasites. In the present study, 1H NMR spectroscopy was used to examine the metabolites outliers in the logarithmic and stationary phases of promastigotes in L. major to enlighten more about the transmission mechanism in metacyclogenesis of L. major. Methods: Promastigote was cultured, logarithmic and stationary phases were separated by the peanut agglutinin, and cell metabolites were extracted. 1H NMR spectroscopy was applied, and outliers were analyzed using principal component analysis. Results: The most altered metabolites in stationary and logarithmic phases were limited to citraconic acid, isopropylmalic acid, L-leucine, ornithine, caprylic acid, capric acid, and acetic acid. Conclusion: 1H NMR spectroscopy could play an important role in the characterization of metabolites in biochemical pathways during a metacyclogenesis process. These metabolites and their pathways can help in exploiting a transmission mechanism in metacyclogenesis, and outcoming data might be used in the metabolic network reconstruction of L. major modeling. PMID:26592771

  7. Highly resolved in vivo 1H NMR spectroscopy of the mouse brain at 9.4 T.

    PubMed

    Tkác, Ivan; Henry, Pierre-Gilles; Andersen, Peter; Keene, C Dirk; Low, Walter C; Gruetter, Rolf

    2004-09-01

    An efficient shim system and an optimized localization sequence were used to measure in vivo 1H NMR spectra from cerebral cortex, hippocampus, striatum, and cerebellum of C57BL/6 mice at 9.4 T. The combination of automatic first- and second-order shimming (FASTMAP) with strong custom-designed second-order shim coils (shim strength up to 0.04 mT/cm2) was crucial to achieve high spectral resolution (water line width of 11-14 Hz). Requirements for second-order shim strengths to compensate field inhomogeneities in the mouse brain at 9.4 T were assessed. The achieved spectral quality (resolution, S/N, water suppression, localization performance) allowed reliable quantification of 16 brain metabolites (LCModel analysis) from 5-10-microL brain volumes. Significant regional differences (up to 2-fold, P < 0.05) were found for all quantified metabolites but Asp, Glc, and Gln. In contrast, 1H NMR spectra measured from the striatum of C57BL/6, CBA, and CBA/BL6 mice revealed only small (<13%, P < 0.05) interstrain differences in Gln, Glu, Ins, Lac, NAAG, and PE. It is concluded that 1H NMR spectroscopy at 9.4 T can provide precise biochemical information from distinct regions of the mouse brain noninvasively that can be used for monitoring of disease progression and treatment as well as phenotyping in transgenic mice models. PMID:15334565

  8. Molecular dynamics and information on possible sites of interaction of intramyocellular metabolites in vivo from resolved dipolar couplings in localized 1H NMR spectra

    NASA Astrophysics Data System (ADS)

    Schröder, Leif; Schmitz, Christian; Bachert, Peter

    2004-12-01

    Proton NMR resonances of the endogenous metabolites creatine and phosphocreatine ((P)Cr), taurine (Tau), and carnosine (Cs, β-alanyl- L-histidine) were studied with regard to residual dipolar couplings and molecular mobility. We present an analysis of the direct 1H- 1H interaction that provides information on motional reorientation of subgroups in these molecules in vivo. For this purpose, localized 1H NMR experiments were performed on m. gastrocnemius of healthy volunteers using a 1.5-T clinical whole-body MR scanner. We evaluated the observable dipolar coupling strength SD0 ( S = order parameter) of the (P)Cr-methyl triplet and the Tau-methylene doublet by means of the apparent line splitting. These were compared to the dipolar coupling strength of the (P)Cr-methylene doublet. In contrast to the aliphatic protons of (P)Cr and Tau, the aromatic H2 ( δ = 8 ppm) and H4 ( δ = 7 ppm) protons of the imidazole ring of Cs exhibit second-order spectra at 1.5 T. This effect is the consequence of incomplete transition from Zeeman to Paschen-Back regime and allows a determination of SD0 from H2 and H4 of Cs as an alternative to evaluating the multiplet splitting which can be measured directly in high-resolution 1H NMR spectra. Experimental data showed striking differences in the mobility of the metabolites when the dipolar coupling constant D0 (calculated with the internuclear distance known from molecular geometry in the case of complete absence of molecular dynamics and motion) is used for comparison. The aliphatic signals involve very small order parameters S ≈ (1.4 - 3) × 10 -4 indicating rapid reorientation of the corresponding subgroups in these metabolites. In contrast, analysis of the Cs resonances yielded S ≈ (113 - 137) × 10 -4. Thus, the immobilization of the Cs imidazole ring owing to an anisotropic cellular substructure in human m. gastrocnemius is much more effective than for (P)Cr and Tau subgroups. Furthermore, 1H NMR experiments on aqueous model

  9. EPR and 1H-NMR spectroscopic studies on the paramagnetic iron at the active site of phenylalanine hydroxylase and its interaction with substrates and inhibitors.

    PubMed

    Martínez, A; Andersson, K K; Haavik, J; Flatmark, T

    1991-06-15

    The paramagnetic iron at the active site of highly purified, catalytically active phenylalanine hydroxylase was studied by EPR at 3.6 K and one-dimensional 1H-NMR spectroscopy at 293 K. The EPR-detectable iron of the bovine enzyme was found to be present as a high-spin form (S = 5/2) in different ligand field symmetries depending on medium conditions (buffer ions) and the presence of ligands known to bind at the active site. At 3.6 K and in phosphate buffer, the paramagnetic iron is coordinated in an environment of rhombic symmetry (g = 4.3), whereas Tris buffer favours an environment of axial ligand field symmetry (g = 6.7, 5.3 and 2.0). The latter axial type of signals resembles those observed at g = 7.0, 5.2 and 1.9 for the enzyme in phosphate buffer when L-noradrenaline is added as an active-site ligand (inhibitor). The same proportion of iron that coordinates to L-noradrenaline seems to be reduced by the pterin cofactor and participate in catalysis. Experimental evidence is presented that Tris inhibits the enzyme by interacting with the enzyme-bound ferric iron and decreases its rate of reduction by the tetrahydropterin cofactor. Preincubation with dithiothreitol also inhibits the enzyme activity and prevents the reduction of its catalytically active ferric iron by pterin cofactors as well as binding of catecholamines to the enzyme. 1H-NMR spectroscopy revealed that the substrate (L-phenylalanine) and L-noradrenaline bind close to the paramagnetic iron, and that the catecholamine displaces the substrate from its binding at the active site. The results support our recently proposed model for the cooperative binding of inhibitor and substrate at the active site [Martínez, A. et al. (1990) Eur. J. Biochem. 193, 211-219]. PMID:1646718

  10. A survey of diamagnetic probes for copper2+ binding to the prion protein. 1H NMR solution structure of the palladium2+ bound single octarepeat.

    PubMed

    Garnett, Anthony P; Jones, Christopher E; Viles, John H

    2006-01-21

    The prion protein (PrP(C)) is a copper binding cell surface glycoprotein which when misfolded causes transmissible spongiform encephalopathies. The cooperative binding of Cu2+ to an unstructured octarepeat sequence within PrP(C) causes profound folding of this region. The use of NMR to determine the solution structure of the octarepeat region of PrP with Cu2+ bound has been hampered by the paramagnetic nature of the Cu2+ ions. Using NMR we have investigated the binding of candidate diamagnetic replacement ions, to the octarepeat region of PrP. We show that Pd2+ forms diamagnetic complexes with the peptides HGGG, HGGGW and QPHGGGWGQ with 1:1 stoichiometry. The 1H NMR spectra indicate that these peptides are in slow-exchange between free and bound Pd2+ on the chemical-shift time-scale. We demonstrate that the Pd-peptide complex forms slowly with a time taken to reach half-maximal signal of 3 hours. Other candidate metal ions, Ni2+, Pt2+ and Au3+, were investigated but only the Pd2+ complexes gave resolvable 1H NMR spectra. We have determined the solution structure of the QPHGGGWGQ-Pd 1:1 complex using 71 NOE distance restraints. A backbone RMSD of 0.30 A was observed over residues 3 to 7 in the final ensemble. The co-ordinating ligands consist of the histidine imidazole side chain N epsilon, the amide N of the second and third glycines with possibly H2O as the fourth ligand. The co-ordination geometry differs markedly from that of the HGGGW-Cu crystal structure. This survey of potential replacement metal ions to Cu2+ provides insight into the metal specificity and co-ordination chemistry of the metal bound octarepeats. PMID:16395451

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

    PubMed

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

    1992-12-01

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

  12. Hydrogen cluster/network in tobermorite as studied by multiple-quantum spin counting {sup 1}H NMR

    SciTech Connect

    Mogami, Yuuki; Yamazaki, Satoru; Matsuno, Shinya; Matsui, Kunio; Noda, Yasuto; Takegoshi, K.

    2014-12-15

    Proton multiple-quantum (MQ) spin-counting experiment has been employed to study arrangement of hydrogen atoms in 9 Å/11 Å natural/synthetic tobermorites. Even though all tobermorite samples give similar characterless, broad static-powder {sup 1}H NMR spectra, their MQ spin-counting spectra are markedly different; higher quanta in 11 Å tobermorite do not grow with the MQ excitation time, while those in 9 Å one do. A statistical analysis of the MQ results recently proposed [26] is applied to show that hydrogens align in 9 Å tobermorite one dimensionally, while in 11 Å tobermorite they exist as a cluster of 5–8 hydrogen atoms.

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

    PubMed

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

    2006-06-01

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

  14. Metabolic Characterization of Advanced Liver Fibrosis in HCV Patients as Studied by Serum 1H-NMR Spectroscopy

    PubMed Central

    Embade, Nieves; Mariño, Zoe; Diercks, Tammo; Cano, Ainara; Lens, Sabela; Cabrera, Diana; Navasa, Miquel; Falcón-Pérez, Juan M.; Caballería, Joan; Castro, Azucena; Bosch, Jaume; Mato, José M.; Millet, Oscar

    2016-01-01

    Several etiologies result in chronic liver diseases including chronic hepatitis C virus infection (HCV). Despite its high incidence and the severe economic and medical consequences, liver disease is still commonly overlooked due to the lack of efficient non-invasive diagnostic methods. While several techniques have been tested for the detection of fibrosis, the available biomarkers still present severe limitations that preclude their use in clinical diagnostics. Liver diseases have also been the subject of metabolomic analysis. Here, we demonstrate the suitability of 1H NMR spectroscopy for characterizing the metabolism of liver fibrosis induced by HCV. Serum samples from HCV patients without fibrosis or with liver cirrhosis were analyzed by NMR spectroscopy and the results were submitted to multivariate and univariate statistical analysis. PLS-DA test was able to discriminate between advanced fibrotic and non-fibrotic patients and several metabolites were found to be up or downregulated in patients with cirrhosis. The suitability of the most significantly regulated metabolites was validated by ROC analysis. Our study reveals that choline, acetoacetate and low-density lipoproteins are the most informative biomarkers for predicting cirrhosis in HCV patients. Our results demonstrate that statistical analysis of 1H-NMR spectra is able to distinguish between fibrotic and non-fibrotic patients suffering from HCV, representing a novel diagnostic application for NMR spectroscopy. PMID:27158896

  15. Lateral diffusion of PEG-Lipid in magnetically aligned bicelles measured using stimulated echo pulsed field gradient 1H NMR.

    PubMed

    Soong, Ronald; Macdonald, Peter M

    2005-01-01

    Lateral diffusion measurements of PEG-lipid incorporated into magnetically aligned bicelles are demonstrated using stimulated echo (STE) pulsed field gradient (PFG) proton (1H) nuclear magnetic resonance (NMR) spectroscopy. Bicelles were composed of dimyristoyl phosphatidylcholine (DMPC) plus dihexanoyl phosphatidylcholine (DHPC) (q = DMPC/DHPC molar ratio = 4.5) plus 1 mol % (relative to DMPC) dimyristoyl phosphatidylethanolamine-N-[methoxy(polyethylene glycol)-2000] (DMPE-PEG 2000) at 25 wt % lipid. 1H NMR STE spectra of perpendicular aligned bicelles contained only resonances assigned to residual HDO and to overlapping contributions from a DMPE-PEG 2000 ethoxy headgroup plus DHPC choline methyl protons. Decay of the latter's STE intensity in the STE PFG 1H NMR experiment (g(z) = 244 G cm(-1)) yielded a DMPE-PEG 2000 (1 mol %, 35 degrees C) lateral diffusion coefficient D = 1.35 x 10(-11) m2 s(-1). Hence, below the "mushroom-to-brush" transition, DMPE-PEG 2000 lateral diffusion is dictated by its DMPE hydrophobic anchor. D was independent of the diffusion time, indicating unrestricted lateral diffusion over root mean-square diffusion distances of microns, supporting the "perforated lamellae" model of bicelle structure under these conditions. Overall, the results demonstrate the feasibility of lateral diffusion measurements in magnetically aligned bicelles using the STE PFG NMR technique. PMID:15475584

  16. [1H-NMR based metabonomic approach to evaluate detoxification effect of vinegar-processed Euphorbia kansui].

    PubMed

    Liu, Yu-Mei; Hui, Rong-Rong; He, Cui-Cui; Duan, Jin-Ao; Li, Jian-Xin

    2014-01-01

    Euphorbia kansui (EK) is a toxic herbal drug, and often used after vinegar-processing to reduce its toxicity. In present study, a 1H-NMR based metabonomic approach was used to evaluate the detoxification effect of vinegar-processed EK. The water extracts of EK and VEK were administered orally to male SD rats at doses of 9 g x kg(-1) x d(-1) for 1 week, respectively, and one more week observation was further conducted. The control group was orally given with saline. Histopathological studies of liver samples on the 8th and 15th day were conducted, and the metabolites of rat urine and liver were analysed by 1H-NMR. Histopathological studies of liver samples from EK and VEK treated rats showed no negative impacts. In metabonomic analyses of urines, changes of metabolites indicated liver damages, kidney lesions and imbalance of gut microbes in the second week. VEK-treated rats showed a quite lower toxicity compared with EK-treated ones. The present study revealed that the metabonomic approach might be helpful for the evaluation of toxicity of EK and detoxic effect of VEK. PMID:24761654

  17. Metabolomics in Lung Inflammation: A High Resolution 1H NMR Study of Mice Exposed to Silica Dust

    PubMed Central

    Hu, Jian Zhi; Rommereim, Donald N.; Minard, Kevin R.; Woodstock, Angie; Harrer, Bruce J.; Wind, Robert A.; Phipps, Richard P.; Sime, Patricia J.

    2010-01-01

    Here we report the first 1H NMR metabolomics studies on excised lungs and bronchoalveolar lavage fluid (BALF) from mice exposed to crystalline silica. High resolution 1H NMR metabolic profiling on intact excised lungs was performed using slow magic angle sample spinning (slow-MAS) 1H PASS (phase altered spinning sidebands) at a sample spinning rate of 80 Hz. Metabolic profiling on BALF was completed using fast magic angle spinning at 2kHz. Major findings are that the relative concentrations of choline, phosphocholine (PC) and glycerophosphocholine(GPC) were statistically significantly increased in silica-exposed mice compared to sham controls, indicating an altered membrane choline phospholipids metabolism (MCPM). The relative concentrations of glycogen/glucose, lactate and creatine were also statistically significantly increased in mice exposed to silica dust, suggesting that cellular energy pathways were affected by silica dust. Elevated levels of glycine, lysine, glutamate, proline and 4-hydroxyproline were also increased in exposed mice, suggesting the activation of a collagen pathway. Furthermore, metabolic profiles in mice exposed to silica dust were found to be spatially heterogeneous, in consistent with regional inflammation revealed by in vivo magnetic resonance imaging (MRI). PMID:20020862

  18. Spin-echo sup 1 H NMR studies of differential mobility in gizzard myosin and its subfragments

    SciTech Connect

    Sommervile, L.E. ); Henry, G.D.; Sykes, B.D. ); Harshorne, D.J. )

    1990-12-01

    The unexpectedly narrow resonances in the {sup 1}H NMR spectra of gizzard myosin, heavy meromyosin, and subfragment 1 were examined by spin-echo NMR spectroscopy. These resonances originated predominantly in the myosin heads, or subfragment 1 units. Smooth muscle myosin undergoes a dramatic change in hydrodynamic properties and can exist either as a folded (10S) or as an extended (6S) species. Factors that influence this transition, namely, ionic strength and phosphorylation (or thiophosphorylation), were varied in the NMR experiments. T{sub 2} relaxation experiments on dephosphorylated myosin indicated several components of different relaxation times that were not influenced by changes in ionic strength. The experiments focused on the components with longer relaxation times, i.e., corresponding to nuclei with more mobility, and these were observed selectively in a spin-echo experiment. With dephosphorylated myosin and HMM, increases in ionic strength caused an increased intensity in several of the narrower resonances. The ionic strength dependence of these changes paralleled that for the 10S and 6S transition. With thiophosphorylated myosin and HMM, changes in ionic strength also influenced the intensities of the narrower resonances, and in addition changes in the {sup 1}H NMR spectrum due to thiophosphorylation were observed. These results suggest that a fraction of the {sup 1}H resonances in smooth muscle myosin and its fragments originates from both aliphatic and aromatic residues of increased mobility compared to the mobility expected from hydrodynamic properties of these proteins.

  19. Correlation of tryptophan fluorescence intensity decay parameters with sup 1 H NMR-determined rotamer conformations: (tryptophan sup 2 )oxytocin

    SciTech Connect

    Ross, J.B.A.; Schwartz, G.P.; Laws, W.R. ); Wyssbrod, H.R.; Porter, R.A. ); Michaels, C.A. )

    1992-02-18

    While the fluorescence decay kinetics of tyrosine model compounds can be explained in terms of heterogeneity derived from the three ground-state {chi}{sup 1} rotamers, a similar correlation has yet to be directly observed for a tryptophan residue. In addition, the asymmetric indole ring might also lead to heterogeneity from {chi}{sup 2} rotations. In this paper, the time-resolved and steady-state fluorescence properties of (tryptophan{sup 2})oxytocin at pH 3 are presented and compared with {sup 1}H NMR results. According to the unrestricted analyses of individual fluorescence decay curves taken as a function of emission wavelength-independent decay constants, only three exponential terms are required. In addition, the preexponential weighting factors (amplitudes) have the same relative relationship (weights) as the {sup 1}H NMR-determined {chi}{sup 1} rotamer populations of the indole side chain. {sup 15}N was used in heteronuclear coupling experiments to confirm the rotamer assignments. Inclusion of a linked function restricting the decay amplitudes to the {chi}{sup 1} rotamer populations in the individual decay curve analyses and in the global analysis confirms this correlation. According to qualitative nuclear Overhauser data, there are two {chi}{sup 2} populations.

  20. 1H NMR study of the effect of heme insertion on the folding of apomyoglobin

    NASA Astrophysics Data System (ADS)

    Yamamoto, Yasuhiko; Takemoto, Kenji; Matsuo, Hitomi

    2002-01-01

    NMR signals arising from His EF5 and His GH1 N ɛH protons of sperm whale myoglobin and apomyoglobin have been assigned, and the protein folding has been studied through the analysis of these signals. His EF5 and His GH1 N ɛH protons participate in the internal hydrogen bonds at the B-GH and EF-H interfaces, respectively, and their signals are remarkably sensitive to local structural alterations at these sites. The shifts of these signals in alkaline pH condition were only slightly affected by the removal of heme, indicating that the overall protein folding is essentially retained in apoprotein. The line width of His EF5 proton signal, however, increased largely in the spectra of apomyoglobin and this result suggests a conformational lability of the EF-H interface in the absence of heme. Furthermore, the His EF5 proton signal was found to be influenced by not only the orientation of heme relative to the protein, but also by the type of hemin used to reconstitute apomyoglobin. These results clearly demonstrate the presence of a long-range structural correlation between the heme active site and the EF-H interface.

  1. 1H NMR Metabolomics: A New Molecular Level Tool for Assessment of Organic Contaminant Bioavailability to Earthworms in Soil

    NASA Astrophysics Data System (ADS)

    McKelvie, J. R.; Wolfe, D. M.; Celejewski, M. A.; Simpson, A. J.; Simpson, M. J.

    2009-05-01

    At contaminated field sites, the complete removal of polycyclic aromatic hydrocarbons (PAHs) is rarely achieved since a portion of these compounds remain tightly bound to the soil matrix. The concentration of PAHs in soil typically decreases until a plateau is reached, at which point the remaining contaminant is considered non- bioavailable. Numerous soil extraction techniques, including cyclodextrin extraction, have been developed to estimate contaminant bioavailability. However, these are indirect methods that do not directly measure the response of organisms to chemical exposure in soil. Earthworm metabolomics offers a promising new way to directly evaluate the bioavailability and toxicity of contaminants in soil. Metabolomics involves the measurement of changes in small-molecule metabolites, including sugars and amino acids, in living organisms due to an external stress, such as contaminant exposure. The objective of this study was to compare cyclodextrin extraction of soil (a bioavailability proxy) and 1H NMR metabolomic analysis of aqueous earthworm tissue extracts as indicators of contaminant bioavailability. A 30 day laboratory experiment was conducted using phenanthrene-spiked sphagnum peat soil and the OECD recommended earthworm species for toxicity testing, Eisenia fetida. The initial phenanthrene concentration in the soil was 320 mg/kg. Rapid biodegradation of phenanthrene occurred and concentrations decreased to 16 mg/kg within 15 days. After 15 days, phenanthrene biodegradation slowed and cyclodextrin extraction of the soil suggested that phenanthrene was no longer bioavailable. Multivariate statistical analysis of the 1H NMR spectra for E. fetida tissue extracts indicated that the metabolic profile of phenanthrene exposed earthworms differed from control earthworms throughout the 30 day experiment. This suggests that the residual phenanthrene remaining in the soil after 15 days continued to elicit a metabolic response, even though it was not

  2. Toward an in Vivo Neurochemical Profile: Quantification of 18 Metabolites in Short-Echo-Time 1H NMR Spectra of the Rat Brain

    NASA Astrophysics Data System (ADS)

    Pfeuffer, Josef; Tkáč , Ivan; Provencher, Stephen W.; Gruetter, Rolf

    1999-11-01

    Localized in vivo1H NMR spectroscopy was performed with 2-ms echo time in the rat brain at 9.4 T. Frequency domain analysis with LCModel showed that the in vivo spectra can be explained by 18 metabolite model solution spectra and a highly structured background, which was attributed to resonances with fivefold shorter in vivo T1 than metabolites. The high spectral resolution (full width at half maximum approximately 0.025 ppm) and sensitivity (signal-to-noise ratio approximately 45 from a 63-μL volume, 512 scans) was used for the simultaneous measurement of the concentrations of metabolites previously difficult to quantify in 1H spectra. The strongly represented signals of N-acetylaspartate, glutamate, taurine, myo-inositol, creatine, phosphocreatine, glutamine, and lactate were quantified with Cramér-Rao lower bounds below 4%. Choline groups, phosphorylethanolamine, glucose, glutathione, γ-aminobutyric acid, N-acetylaspartylglutamate, and alanine were below 13%, whereas aspartate and scyllo-inositol were below 22%. Intra-assay variation was assessed from a time series of 3-min spectra, and the coefficient of variation was similar to the calculated Cramér-Rao lower bounds. Interassay variation was determined from 31 pooled spectra, and the coefficient of variation for total creatine was 7%. Tissue concentrations were found to be in very good agreement with neurochemical data from the literature.

  3. Quantification of metabolites from single-voxel in vivo 1H NMR data of normal human brain by means of time-domain data analysis.

    PubMed

    Ala-Korpela, M; Usenius, J P; Keisala, J; van den Boogaart, A; Vainio, P; Jokisaari, J; Soimakallio, S; Kauppinen, R

    1995-01-01

    We present here a combination of time-domain signal analysis procedures for quantification of human brain in vivo 1H NMR spectroscopy (MRS) data. The method is based on a separate removal of a residual water resonance followed by a frequency-selective time-domain line-shape fitting analysis of metabolite signals. Calculation of absolute metabolite concentrations was based on the internal water concentration as a reference. The estimated average metabolite concentrations acquired from six regions of normal human brain with a single-voxel spin-echo technique for the N-acetylaspartate, creatine, and choline-containing compounds were 11.4 +/- 1.0, 6.5 +/- 0.5, and 1.7 +/- 0.2 mumol kg-1 wet weight, respectively. The time-domain analyses of in vivo 1H MRS data from different brain regions with their specific characteristics demonstrate a case in which the use of frequency-domain methods pose serious difficulties. PMID:8749730

  4. /sup 13/C and /sup 1/H NMR spectra and structure of the products from the condensation of 1,3-dicarbonyl compounds with aldehydes

    SciTech Connect

    Emelina, E.E.; Gindin, V.A.; Ershov, B.A.

    1988-05-20

    The structure of the diadducts formed in the reaction of 1,3-dicarbonyl compounds with aldehydes in a ratio of 2:1 under the conditions of the Knoevenagel condensation was studied by /sup 13/C and /sup 1/H NMR spectroscopy. It was shown that acyclic tetracarbonyl compounds are formed in the absence of a catalyst while substituted cyclohexanones are formed in the presence of piperidine. The acyclic tetracarbonyl compounds exist mainly in the tetraketo form in solution, and the presence of the monoenol form was established for dimethyl 2,4-diacetylpentanedioate in CD/sub 2/Cl/sub 2/. The most characteristic signals which distinguish between the cyclic diadducts and the acyclic products are the signals of the C/sup 5/ (delta 72 ppm) and C/sup 6/ (delta 52 ppm) atoms. The presence of a keto-enol equilibrium in 2,4-diacetyl-5-hydroxy-3-(p-methoxyphenyl)-5-methylcyclohexanone was demonstrated by /sup 13/C NMR.

  5. Thermodynamic behavior of the binaries 1-butylpyridinium tetrafluoroborate with water and alkanols: their interpretation using 1H NMR spectroscopy and quantum-chemistry calculations.

    PubMed

    Vreekamp, Remko; Castellano, Desire; Palomar, José; Ortega, Juan; Espiau, Fernando; Fernández, Luís; Penco, Eduvigis

    2011-07-14

    Here we present experimental data of different properties for a set of binary mixtures composed of water or alkanols (methanol to butanol) with an ionic liquid (IL), butylpyridinium tetrafluoroborate [bpy][BF(4)]. Solubility data (x(IL),T) are presented for each of the mixtures, including water, which is found to have a small interval of compositions in IL, x(IL), with immiscibility. In each case, the upper critical solubility temperature (UCST) is determined and a correlation was observed between the UCST and the nature of the compounds in the mixtures. Miscibility curves establish the composition and temperature intervals where thermodynamic properties of the mixtures, such as enthalpies H(m)(E) and volumes V(m)(E), can be determined. Hence, at 298.15 and 318.15 K these can only be found with the first four alkanols. All mixing properties are correlated with a suitable equation ξ (x(IL),T,Y(m)(E) = 0. An analysis on the influence of the temperature in the properties is shown, likewise a comparison between the results obtained here and those of analogous mixtures, discussing the position of the -CH(3) group in the pyridinic ring. The (1)H NMR spectra are determined to analyze the molecular interactions present, especially those due to hydrogen bonds. Additional information about the molecular interactions and their influence on the mixing properties is obtained by quantum chemistry calculations. PMID:21648473

  6. Metabolomics study of Saw palmetto extracts based on 1H NMR spectroscopy.

    PubMed

    de Combarieu, Eric; Martinelli, Ernesto Marco; Pace, Roberto; Sardone, Nicola

    2015-04-01

    Preparations containing Saw palmetto extracts are used in traditional medicine to treat benign prostatic hyperplasia. According to the European and the American Pharmacopoeias, the extract is obtained from comminuted Saw palmetto berries by a suitable extracting procedure using ethanol or supercritical carbon dioxide or a mixture of n-hexane and methylpentanes. In the present study an approach to metabolomics profiling using nuclear magnetic resonance (NMR) has been used as a finger-printing tool to assess the overall composition of the extracts. The phytochemical analysis coupled with principal component analysis (PCA) showed the same composition of the Saw palmetto extracts obtained with carbon dioxide and hexane with minor not significant differences for extracts obtained with ethanol. In fact these differences are anyhow lower than the batch-to-batch variability ascribable to the natural-occurring variability in the Saw palmetto fruits' phytochemical composition. The fingerprinting analysis combined with chemometric method, is a technique, which would provide a tool to comprehensively assess the quality control of Saw palmetto extracts. PMID:25707588

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

    PubMed

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

    2016-10-20

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

  8. Conformational studies of DL-lactaldehyde by 1H-NMR, Raman and i.r. spectroscopy

    NASA Astrophysics Data System (ADS)

    Takahashi, Hiroaki; Kobayashi, Yoko; Kaneko, Norio

    1H-NMR, Raman and i.r. spectra of DL-lactaldehyde reveal that this compound crystallizes in three different crystal forms. All of them consist of hemiacetal dimers having the same 1,4-dioxane ring skeleton but with different configurations (e,e), (e,a) and (a,a) with respect to the two OH groups attached to the ring (e and a denote equatorial and axial, respectively). In addition to these three species, the monomer and at least one five-membered ring dimer, though both in negligibly small amount, exist in equilibrium solution. The most easily obtainable species in the crystalline state has the centrosymmetric configuration (a,a) which is least populated in solution. The existence of the crystal form which consists of non-centrosymmetric dimers having the (e,a) configuration is in contrast to simple carbohydrates such as glycolaldehyde, glyceraldehyde and 1,3-dihydroxyacetone which crystallize only as centrosymmetric dimers.

  9. Study of the Cardiotoxicity of Venenum Bufonis in Rats using an 1H NMR-Based Metabolomics Approach

    PubMed Central

    Wang, Junsong; Guo, Pingping; Li, Minghui; Yang, Minghua; Kong, Lingyi

    2015-01-01

    Venenum Bufonis, a well-known traditional Chinese medicine, has been widely used in Asia and has gained popularity in Western countries over the last decade. Venenum Bufonis has obvious side effects that have been observed in clinical settings, but few studies have reported on its cardiotoxicity. In this work, the cardiotoxicity of Venenum Bufonis was investigated using a 11H NMR-based metabolomics approach. The 1H NMR profiles of the serum, myocardial extracts and liver extracts of specific-pathogen-free rats showed that Venenum Bufonis produced significant metabolic perturbations dose-dependently with a distinct time effect, peaking at 2 hr after dosing and attenuating gradually. Clinical chemistry, electrocardiographic recordings, and histopathological evaluation provided additional evidence of Venenum Bufonis-induced cardiac damage that complemented and supported the metabolomics findings. The combined results demonstrated that oxidative stress, mitochondrial dysfunction, and energy metabolism perturbations were associated with the cardiac damage that results from Venenum Bufonis. PMID:25781638

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

    NASA Astrophysics Data System (ADS)

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

    1999-05-01

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

  11. High Resolution 1H NMR Spectroscopy in Rat Liver Using Magic Angle Turning at a 1 Hz Spinning Rate

    SciTech Connect

    Hu, Jian Zhi ); Rommereim, Donald N. ); Wind, Robert A. )

    2001-12-01

    It is demonstrated that a high resolution 1H NMR spectrum of excised rat liver can be obtained using the technique of magic angle turning at a sample spinning rate of 1 Hz. A variant of the phase-corrected magic angle turning (PHORMAT) pulse sequence that includes a water suppression segment was developed for the investigation. The spectral resolution achieved with PHORMAT is approaching that obtained from a standard magic angle spinning experiment at a spinning rate of several kHz. With such ultra-slow spinning, tissue and cell damage associated with the standard MAS experiment is minimized or eliminated. The technique is potentially useful for obtaining high-resolution 1H spectra in live animals.

  12. Characterization of Adsorbed Molecular Water on the Surface of a Stretched Polytetrafluoroethylene Tape Analyzed by (1)H NMR.

    PubMed

    Wakai, Chihiro; Shimoaka, Takafumi; Hasegawa, Takeshi

    2016-03-10

    A single molecule often exhibits a largely different material character from a bulk matter. Although a perfluoroalkyl (Rf) compound is a representative one, many interests have mostly been devoted to the bulk character only thus far, leaving the single molecular character unclear. Recently, a new theoretical framework, stratified dipole-arrays (SDA) theory, has appeared for comprehensive understanding of Rf compounds in terms of both single and bulk systems. On this theory, a mechanically stretched polytetrafluoroethylene (PTFE) is expected to exhibit a single-molecular character having dipole-driven properties, which should attract molecular water. In the present study, a stretched PTFE tape is revealed to attract molecular water (not water droplet) in fact, and the adsorbed water molecules are highly restricted in motion by the dipole-dipole interaction studied by using (1)H NMR, which agrees with the prediction by the SDA theory. PMID:26848611

  13. 1H NMR analysis of complexation of hydrotropic agents nicotinamide and caffeine with aromatic biologically active molecules in aqueous solution

    NASA Astrophysics Data System (ADS)

    Lantushenko, Anastasia O.; Mukhina, Yulia V.; Veselkov, Kyrill A.; Davies, David B.; Veselkov, Alexei N.

    2004-07-01

    NMR spectroscopy has been used to elucidate the molecular mechanism of solubilization action of hydrotropic agents nicotinamide (NA) and caffeine (CAF). Hetero-association of NA with riboflavine-mononucleotide (FMN) and CAF with low soluble in aqueous solution synthetic analogue of antibiotic actinomycin D, actinocyl-bis-(3-dimethylaminopropyl) amine (Actill), has been investigated by 500 MHz 1H NMR spectroscopy. Concentration and temperature dependences of proton chemical shifts have been analysed in terms of a statistical-thermodynamic model of indefinite self- and heteroassociation of aromatic molecules. The obtained results enable to conclude that NA-FMN and CAF-Actill intermolecular complexes are mainly stabilized by the stacking interactions of the aromatic chromophores. Hetero-association of the investigated molecules plays an important role in solubilization of aromatic drugs by hydrotropic agents nicotinamide and caffeine.

  14. Rapid determination of γ-value and xanthate group distribution on viscose by liquid-state (1)H NMR spectroscopy.

    PubMed

    Wöss, Kateryna; Weber, Hansjörg; Grundnig, Peter; Röder, Thomas; Weber, Hedda K

    2016-05-01

    A method for the determination of the γ-value and more importantly the distribution of xanthate groups on cellulose xanthate produced during the viscose process is presented. The method is based upon stabilization of xanthate groups attached to the cellulose chain by reaction with 4-methylbenzyl bromide and analysis of the resulting product by liquid-state (1)H NMR. Careful analysis of the proton-spectrum using deconvolution gave a very fast method for the measurement of the γ-value which compared well with the data obtained by IR spectroscopy. In addition it could be shown that the distribution of the xanthate groups on the anhydroglucose monomeric unit (xanthation at position 2, 3 or 6) changes significantly during ripening. The method gave useful results even for viscose with low γ-values of about 25. PMID:26877011

  15. Bonding in hard and elastic amorphous carbon nitride films investigated using 15N, 13C, and 1H NMR spectroscopy

    NASA Astrophysics Data System (ADS)

    Gammon, W. J.; Hoatson, G. L.; Holloway, B. C.; Vold, R. L.; Reilly, A. C.

    2003-11-01

    The nitrogen bonding in hard and elastic amorphous carbon nitride (a-CNx) films is examined with 15N, 13C, and 1H nuclear magnetic resonance (NMR) spectroscopy. Films were deposited by dc magnetron sputtering, in a pure nitrogen discharge on Si(001) substrates at 300 °C. Nanoindentation tests revealed an elastic recovery of 80%, a hardness of 5 GPa, and an elastic modulus of 47 GPa. The NMR results show that nitrogen bonding in this material is consistent with sp2 hybridized nitrogen incorporated in an aromatic carbon environment. The data also indicate that the a-CNx prepared for this study has very low hydrogen content and is hydrophilic. Specifically, analysis of 15N and 13C cross polarization magic angle spinning and 1H NMR experiments suggests that water preferentially protonates nitrogen sites.

  16. Aggregation in five-coordinate high-spin natural hemins: Determination of solution structure by sup 1 H NMR

    SciTech Connect

    Mazumdar, S.; Mitra, S. )

    1990-01-25

    {sup 1}H NMR measurements (at 500 MHz) of nuclear spin-spin relaxation time T{sub 2} (from NMR line width) at different temperatures are reported for aggregates of several five-coordinate high-spin iron(III) complexes of proto-, deutero-, and coproporphyrins in solution and are utilized to determine their solution structure. Extensive aggregation of these complexes in solution is observed, and the dominant form of the aggregates is shown to be dimers. The degree of aggregation for these iron(III) porphyrins follows the order proto- >> deutero- > copro-. The line width of the heme methyl resonances was analyzed by using a nonlinear least-squares fit program working in finite difference algorithm. The values of T{sub 2} were used to determine the structural details of the dimer.

  17. Two-dimensional sup 1 H NMR studies on HPr protein from Staphylococcus aureus: Complete sequential assignments and secondary structure

    SciTech Connect

    Kalbitzer, H.R.; Neidig, K.P. ); Hengstenberg, W. )

    1991-11-19

    Complete sequence-specific assignments of the {sup 1}H NMR spectrum of HPr protein from Staphylococcus aureus were obtained by two-dimensional NMR methods. Important secondary structure elements that can be derived from the observed nuclear Overhauser effects are a large antiparallel {beta}-pleated sheet consisting of four strands, A, B, C, D, a segment S{sub AB} consisting of an extended region around the active-center histidine (His-15) and an {alpha}-helix, a half-turn between strands B and C, a segment S{sub CD} which shows no typical secondary structure, and the {alpha}-helical, C-terminal segment S{sub term}. These general structural features are similar to those found earlier in HPr proteins from different microorganisms such as Escherichia coli, Bacillus subtilis, and Streptococcus faecalis.

  18. IR, 1H NMR, mass, XRD and TGA/DTA investigations on the ciprofloxacin/iodine charge-transfer complex

    NASA Astrophysics Data System (ADS)

    Refat, Moamen S.; El-Hawary, W. F.; Moussa, Mohamed A. A.

    2011-05-01

    The charge-transfer complex (CTC) of ciprofloxacin drug (CIP) as a donor with iodine (I 2) as a sigma acceptor has been studied spectrophotometrically in CHCl 3. At maximum absorption bands, the stoichiometry of CIP:iodine system was found to be 1:1 ratio according to molar ratio method. The essential spectroscopic data like formation constant ( KCT), molar extinction coefficient ( ɛCT), standard free energy (Δ G°), oscillator strength ( f), transition dipole moment ( μ), resonance energy ( RN) and ionization potential ( ID) were estimated. The spectroscopic techniques such as IR, 1H NMR, mass and UV-vis spectra and elemental analyses (CHN) as well as TG-DTG and DTA investigations were used to characterize the chelating behavior of CIP/iodine charge-transfer complex. The iodine CT interaction was associated with a presence of intermolecular hydrogen bond. The X-ray investigation was carried out to investigate the iodine doping in the synthetic CT complex.

  19. Metabolic profiling studies on the toxicological effects of realgar in rats by {sup 1}H NMR spectroscopy

    SciTech Connect

    Wei Lai; Liao Peiqiu; Wu Huifeng; Li Xiaojing Pei Fengkui Li Weisheng; Wu Yijie

    2009-02-01

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

  20. 1H NMR Metabolic Fingerprinting to Probe Temporal Postharvest Changes on Qualitative Attributes and Phytochemical Profile of Sweet Cherry Fruit

    PubMed Central

    Goulas, Vlasios; Minas, Ioannis S.; Kourdoulas, Panayiotis M.; Lazaridou, Athina; Molassiotis, Athanassios N.; Gerothanassis, Ioannis P.; Manganaris, George A.

    2015-01-01

    Sweet cherry fruits (Prunus avium cvs. ‘Canada Giant’, ‘Ferrovia’) were harvested at commercial maturity stage and analyzed at harvest and after maintenance at room temperature (storage at ∼20°C, shelf life) for 1, 2, 4, 6, and 8 days, respectively. Fruit were initially analyzed for respiration rate, qualitative attributes and textural properties: ‘Canada Giant’ fruit were characterized by higher weight losses and stem browning index, being more intense over the late stages of shelf life period; meanwhile ‘Ferrovia’ possessed appreciably better performance even after extended shelf life period. A gradual decrease of respiration rate was monitored in both cultivars, culminated after 8 days at 20°C. The sweet cherry fruit nutraceutical profile was monitored using an array of instrumental techniques (spectrophotometric assays, HPLC, 1H-NMR). Fruit antioxidant capacity was enhanced with the progress of shelf life period, concomitant with the increased levels of total anthocyanin and of phenolic compounds. ‘Ferrovia’ fruit presented higher contents of neochlorogenic acid and p-coumaroylquinic acid throughout the shelf life period. We further developed an 1H-NMR method that allows the study of primary and secondary metabolites in a single running, without previous separation and isolation procedures. Diagnostic peaks were located in the aliphatic region for sugars and organic acids, in the aromatic region for phenolic compounds and at 8.2–8.6 ppm for anthocyanins. This NMR-based methodology provides a unifying tool for quantitative and qualitative characterization of metabolite changes of sweet cherry fruits; it is also expected to be further exploited for monitoring temporal changes in other fleshy fruits. PMID:26617616

  1. (1)H NMR Metabolic Fingerprinting to Probe Temporal Postharvest Changes on Qualitative Attributes and Phytochemical Profile of Sweet Cherry Fruit.

    PubMed

    Goulas, Vlasios; Minas, Ioannis S; Kourdoulas, Panayiotis M; Lazaridou, Athina; Molassiotis, Athanassios N; Gerothanassis, Ioannis P; Manganaris, George A

    2015-01-01

    Sweet cherry fruits (Prunus avium cvs. 'Canada Giant', 'Ferrovia') were harvested at commercial maturity stage and analyzed at harvest and after maintenance at room temperature (storage at ∼20°C, shelf life) for 1, 2, 4, 6, and 8 days, respectively. Fruit were initially analyzed for respiration rate, qualitative attributes and textural properties: 'Canada Giant' fruit were characterized by higher weight losses and stem browning index, being more intense over the late stages of shelf life period; meanwhile 'Ferrovia' possessed appreciably better performance even after extended shelf life period. A gradual decrease of respiration rate was monitored in both cultivars, culminated after 8 days at 20°C. The sweet cherry fruit nutraceutical profile was monitored using an array of instrumental techniques (spectrophotometric assays, HPLC, (1)H-NMR). Fruit antioxidant capacity was enhanced with the progress of shelf life period, concomitant with the increased levels of total anthocyanin and of phenolic compounds. 'Ferrovia' fruit presented higher contents of neochlorogenic acid and p-coumaroylquinic acid throughout the shelf life period. We further developed an (1)H-NMR method that allows the study of primary and secondary metabolites in a single running, without previous separation and isolation procedures. Diagnostic peaks were located in the aliphatic region for sugars and organic acids, in the aromatic region for phenolic compounds and at 8.2-8.6 ppm for anthocyanins. This NMR-based methodology provides a unifying tool for quantitative and qualitative characterization of metabolite changes of sweet cherry fruits; it is also expected to be further exploited for monitoring temporal changes in other fleshy fruits. PMID:26617616

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

    PubMed

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

    2005-11-10

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

  3. Combining biochemical with (1)H NMR-based metabolomics approach unravels the antidiabetic activity of genipin and its possible mechanism.

    PubMed

    Shen, Xiao-Li; Liu, Huan; Xiang, Huan; Qin, Xue-Mei; Du, Guan-Hua; Tian, Jun-Sheng

    2016-09-10

    Diabetes mellitus is a typical heterogeneous metabolic disorder characterized by abnormal metabolism of carbohydrates, lipids and proteins. Genipin possesses a wide spectrum of biological activities including ameliorating effects on diabetes, but the definite mechanism of this effect remains unknown. To investigate the antidiabetic activities of genipin and explore the biochemical changes of serum endogenous metabolites on diabetic rats induced by alloxan, (1)H NMR spectroscopy coupled with multivariate data analysis was used to. All rats were randomly divided into six groups including negative control (NC) group, diabetic mellitus (DM) group, metformin hydrochloride group, high dose group of genipin, middle dose group of genipin and low dose group of genipin. Diabetes was induced by a single intraperitoneal injection of 120mg/kg body weight of alloxan. Serum samples were collected for the (1)H NMR-based metabolomics and clinical biochemical analysis. Daily oral administration of genipin (25, 50 and 100mg/kg body weight) and metformin hydrochloride (125mg/kg) for two weeks showed beneficial effects on blood glucose level (P<0.01). Significant differences in the metabolic profile as well as the result of biochemical parameters between the diabetic group and the control group were observed. The PLS-DA scores and corresponding loading plots demonstrated that genipin significantly restored the abnormal metabolic state. Detailed analysis of the altered metabolite levels indicated that genipin significantly ameliorated the disturbance in glucose metabolism, tricarboxylic acid cycle, lipid metabolism and amino acid metabolism. Genipin showed the best anti-diabetic effects at a dose of 100mg/kg in rats. This finding indicates that chemical and metabolomic approaches could be powerful tools for the investigation of the biochemical changes in pathological conditions or drug treatment. PMID:27411170

  4. New approach for characterization of gelatin biopolymer films using proton behavior determined by low field 1H NMR spectrometry.

    PubMed

    Kim, Young-Teck; Hong, Young-Shick; Kimmel, Robert M; Rho, Jeong-Hae; Lee, Cherl-Ho

    2007-12-26

    The behavior of protons in biopolymer films (BFs) formed with gelatin, water, and glycerol was investigated at various relative humidities (RHs) and concentrations of glycerol using a low field 1H NMR spectrometer. At a RH of approximately 0%, the distributed spin-spin relaxation times (T2) of protons in BFs showed two components: a rapidly relaxing proton with the shortest T2 derived from protons in the rigid backbone of the gelatin polymer such as CH1-, CH2-, and CH3-, and a slowly relaxing component with longer T2 from protons of the functional groups in amino acid residues in gelatin such as -OH, -COOH, and -NH3. These two components are referred to as nonexchangeable (T2N) and exchangeable protons (T2E), respectively, indicating the different mobility of the protons. The T2E increased as RH increased indicating the increase in relative mobility of protons due to the larger free volume in the BF matrix. Above a RH of 33%, the slowest relaxing component was found in all BFs and referred to as hydration-water protons (T2W) with the highest relative mobility of all protons in the films. It suggests that the free volume in BFs can be formed above a RH of 33% in the absence of glycerol. The behaviors of T2N, T2E, and T2W reveal the formation of free volume in the BF matrix associated with the presence of plasticizers (water and glycerol). The T2 behavior in BFs is consistent with the behavior of spin-lattice relaxation (T1). Our result is the first attempt to characterize using low field 1H NMR technology how all protons in a film matrix behave and to develop correlations between proton mobility and free volume in protein-based BFs plasticized with water and glycerol. PMID:18052122

  5. Metabolic signatures of Huntington's disease (HD): (1)H NMR analysis of the polar metabolome in post-mortem human brain.

    PubMed

    Graham, Stewart F; Kumar, Praveen K; Bjorndahl, Trent; Han, BeomSoo; Yilmaz, Ali; Sherman, Eric; Bahado-Singh, Ray O; Wishart, David; Mann, David; Green, Brian D

    2016-09-01

    Huntington's disease (HD) is an autosomal neurodegenerative disorder affecting approximately 5-10 persons per 100,000 worldwide. The pathophysiology of HD is not fully understood but the age of onset is known to be highly dependent on the number of CAG triplet repeats in the huntingtin gene. Using (1)H NMR spectroscopy this study biochemically profiled 39 brain metabolites in post-mortem striatum (n=14) and frontal lobe (n=14) from HD sufferers and controls (n=28). Striatum metabolites were more perturbed with 15 significantly affected in HD cases, compared with only 4 in frontal lobe (p<0.05; q<0.3). The metabolite which changed most overall was urea which decreased 3.25-fold in striatum (p<0.01). Four metabolites were consistently affected in both brain regions. These included the neurotransmitter precursors tyrosine and l-phenylalanine which were significantly depleted by 1.55-1.58-fold and 1.48-1.54-fold in striatum and frontal lobe, respectively (p=0.02-0.03). They also included l-leucine which was reduced 1.54-1.69-fold (p=0.04-0.09) and myo-inositol which was increased 1.26-1.37-fold (p<0.01). Logistic regression analyses performed with MetaboAnalyst demonstrated that data obtained from striatum produced models which were profoundly more sensitive and specific than those produced from frontal lobe. The brain metabolite changes uncovered in this first (1)H NMR investigation of human HD offer new insights into the disease pathophysiology. Further investigations of striatal metabolite disturbances are clearly warranted. PMID:27288730

  6. I. The synthesis and characterization of annulated uranocenes. II. The variable temperature /sup 1/H NMR of uranocenes

    SciTech Connect

    Luke, W.D.

    1980-01-01

    A general synthetic route to alkyl annulated cyclooctatetraene dianions and the corresponding annulated uranocenes has been developed. Dideprotonation of bicyclooctatrienes, resulting from reaction of cyclooctatetraene dianion with l,n-dialkylbromides or methanesulfonates, affords alkyl annulated cyclooctatetraene dianions in moderate yields. Dicyclopenteno-, bisdimethylcyclopenteno- and dicyclohexenouranocene were prepared from the corresponding cyclooctatetraene dianions and UCl/sub 4/. The structures of dicyclobuteno- and dicyclopentenouranocene were elucidated by single crystal X-ray diffraction, and the effects of annulation on the uranocene skeleton are discussed. Attempted synthesis of benzocyclooctatetraene and a benzannulated uranocene is reported. The variable temperature /sup 1/H NMR spectrum of uranocene has been reinvestigated from -100 to 100/sup 0/C. The isotropic shift was found to be linear in T/sup -1/ with an extrapolated intercept of 0 at T/sup -1/ = 0. Variable temperature /sup 1/H NMR spectra, from -80 to 70/sup 0/C, of 17 substituted uranocenes are reported. The energy barrier to ring rotation in 1,1', 4,4'-tetra-t-butyl-uranocene was determined to be 8.24 +- 0.5 kcal/mole while the barrier in the corresponding 1,1', 3,3'-tetra-t-butylferrocene was determined to be 13.1 kcal/mole. Alkyl substitution is shown to have little effect on the electronic and magnetic properties of the uranocene skeleton, and thus alkyl substituted uranocenes are treated as having effective axial symmetry in analysis of the observed isotropic shifts. Using diannulated uranocenes as model systems an analysis of the contact and pseudocontact components of the observed isotropic shifts in uranocene and alkyl substituted uranocenes is presented.

  7. Survey and qualification of internal standards for quantification by 1H NMR spectroscopy.

    PubMed

    Rundlöf, Torgny; Mathiasson, Marie; Bekiroglu, Somer; Hakkarainen, Birgit; Bowden, Tim; Arvidsson, Torbjörn

    2010-09-01

    In quantitative NMR (qNMR) selection of an appropriate internal standard proves to be crucial. In this study, 25 candidate compounds considered to be potent internal standards were investigated with respect to the ability of providing unique signal chemical shifts, purity, solubility, and ease of use. The (1)H chemical shift (delta) values, assignments, multiplicities and number of protons (for each signal), appropriateness (as to be used as internal standards) in four different deuterated solvents (D(2)O, DMSO-d(6), CD(3)OD, CDCl(3)) were studied. Taking into account the properties of these 25 internal standards, the most versatile eight compounds (2,4,6-triiodophenol, 1,3,5-trichloro-2-nitrobenzene, 3,4,5-trichloropyridine, dimethyl terephthalate, 1,4-dinitrobenzene, 2,3,5-triiodobenzoic acid, maleic acid and fumaric acid) were qualified using both differential scanning calorimetry (DSC) and NMR spectroscopy employing highly pure acetanilide as the reference standard. The data from these two methods were compared as well as utilized in the quality assessment of the compounds as internal standards. Finally, the selected internal standards were tested and evaluated in a real case of quantitative NMR analysis of a paracetamol pharmaceutical product. PMID:20207092

  8. Bulk magnetization and 1H NMR spectra of magnetically heterogeneous model systems

    SciTech Connect

    Levin, E M; Bud' ko, S L

    2011-04-28

    Bulk magnetization and ¹H static and magic angle spinning (MAS) nuclear magnetic resonance (NMR) spectra of two magnetically heterogeneous model systems based on laponite (LAP) layered silicate or polystyrene (PS) with low and high proton concentration, respectively, and ferrimagnetic Fe₂O₃ nano- or micro-particles have been studied. In LAP+Fe₂O₃, a major contribution to the NMR signal broadening is due to the dipolar coupling between the magnetic moments of protons and magnetic particles. In PS+Fe₂O₃, due to the higher proton concentration in polystyrene and stronger proton–proton dipolar coupling, an additional broadening is observed, i.e. ¹H MAS NMR spectra of magnetically heterogeneous systems are sensitive to both proton–magnetic particles and proton–proton dipolar couplings. An increase of the volume magnetization by ~1 emu/cm³ affects the ¹H NMR signal width in a way that is similar to an increase of the proton concentration by ~2×10²²/cm³. ¹H MAS NMR spectra, along with bulk magnetization measurements, allow the accurate determination of the hydrogen concentration in magnetically heterogeneous systems.

  9. 13C and 1H NMR (Nuclear Magnetic Resonance) studies of solid polyolefines

    NASA Technical Reports Server (NTRS)

    Cudby, M. E. A.; Harris, R. K.; Metcalfe, K.; Packer, K. J.; Smith, P. W. R.

    1983-01-01

    The basis of H-1 and C-13 high-resolution NMR investigations of solid polymers is outlined. The C-13 NMR spectra of solid syndiotactic and isotactic polypropene are discussed and their interpretation in terms of conformation and chain-packing effects are reviewed. The effects of decreasing temperature on the C-13 high-resolution spectrum of an annealed sample of isotactic polypropene is described and interpreted in terms of the crystal structure. The question of the proportion of the sample giving rise to C-13 signals is addressed and some results reported. The main cause for observing only part of the total sample is shown to be the H-1 rotating frame spin-lattice relaxation behavior. The H-1 spin-lattice relaxation and spectral characteristics of a number of polyolefin samples are summarized and the role of spin-diffusion discussed.

  10. 1H-NMR study of the three low temperature phases of DPPC-water systems.

    PubMed

    Trahms, L; Klabe, W D; Boroske, E

    1983-06-01

    The three phases of dipalmitoylphosphatidylcholine-water dispersions, occurring below the main transition are studied by a moment analysis of 1H-nuclear magnetic resonance (NMR) spectra. The subtransition, recently detected by Chen, S. C., J. M. Sturtevant, and B. J. Gaffney, 1980, Pro. Natl. Acad. Sci. USA, 77:5060-5063, is characterized by a sharp drop in the second moment at 12 degrees C as a result of increasing the temperature. Interesting features of this phase transition are a hysteresis of 11 K and extremely slow kinetics. It is interpreted as the onset of a flip-flop of the hydrocarbon chains about their long axis. At the pretransition, this type of motion is assumed to change into a fast rotation. The proposed models for the three phases are confirmed by computer calculations of theoretical values for the second and fourth moments of the corresponding NMR signals. PMID:6688190

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

    PubMed

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

    2016-08-01

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

  12. Spectroscopic study (DRIFT, SERS and 1H NMR) of peat, leonardite and lignite humic substances

    NASA Astrophysics Data System (ADS)

    Francioso, O.; Sànchez-Cortés, S.; Tugnoli, V.; Marzadori, C.; Ciavatta, C.

    2001-05-01

    Diffuse reflectance infrared Fourier transform, surface-enhanced Raman and proton nuclear magnetic resonance spectroscopies were applied to investigate the structure of humic acids (HA) extracted from peat (P-HA), leonardite (Le-HA) and lignite (Li-HA) samples. The combined use of these techniques has shown a specific pattern of functional groups for each sample. P-HA was characterised by a greater content of oxygenate (COOH, C-OH in carbohydrates and phenols) and aliphatic groups. Le-HA and Li-HA showed a lower content of sugar-like components and polyethers. On the other hand, the aromatic structures were ubiquitous in all samples, although the different composition in Le-HA and Li-HA could be employed to identify and distinguish the HA in these two kinds of humic materials.

  13. Automated Quantification of Human Brain Metabolites by Artificial Neural Network Analysis from in VivoSingle-Voxel 1H NMR Spectra

    NASA Astrophysics Data System (ADS)

    Kaartinen, Jouni; Mierisová, Šarka; Oja, Joni M. E.; Usenius, Jukka-Pekka; Kauppinen, Risto A.; Hiltunen, Yrjö

    1998-09-01

    A real-time automated way of quantifying metabolites fromin vivoNMR spectra using an artificial neural network (ANN) analysis is presented. The spectral training and test sets for ANN containing peaks at the chemical shift ranges resembling long echo time proton NMR spectra from human brain were simulated. The performance of the ANN constructed was compared with an established lineshape fitting (LF) analysis using both simulated and experimental spectral data as inputs. The correspondence between the ANN and LF analyses showed correlation coefficients of order of 0.915-0.997 for spectra with large variations in both signal-to-noise and peak areas. Water suppressed1H NMR spectra from 24 healthy subjects were collected and choline-containing compounds (Cho), total creatine (Cr), and N-acetyl aspartate (NAA) were quantified with both methods. The ANN quantified these spectra with an accuracy similar to LF analysis (correlation coefficients of 0.915-0.951). These results show that LF and ANN are equally good quantifiers; however, the ANN analyses are more easily automated than LF analyses.

  14. mQTL.NMR: an integrated suite for genetic mapping of quantitative variations of (1)H NMR-based metabolic profiles.

    PubMed

    Hedjazi, Lyamine; Gauguier, Dominique; Zalloua, Pierre A; Nicholson, Jeremy K; Dumas, Marc-Emmanuel; Cazier, Jean-Baptiste

    2015-04-21

    High-throughput (1)H nuclear magnetic resonance (NMR) is an increasingly popular robust approach for qualitative and quantitative metabolic profiling, which can be used in conjunction with genomic techniques to discover novel genetic associations through metabotype quantitative trait locus (mQTL) mapping. There is therefore a crucial necessity to develop specialized tools for an accurate detection and unbiased interpretability of the genetically determined metabolic signals. Here we introduce and implement a combined chemoinformatic approach for objective and systematic analysis of untargeted (1)H NMR-based metabolic profiles in quantitative genetic contexts. The R/Bioconductor mQTL.NMR package was designed to (i) perform a series of preprocessing steps restoring spectral dependency in collinear NMR data sets to reduce the multiple testing burden, (ii) carry out robust and accurate mQTL mapping in human cohorts as well as in rodent models, (iii) statistically enhance structural assignment of genetically determined metabolites, and (iv) illustrate results with a series of visualization tools. Built-in flexibility and implementation in the powerful R/Bioconductor framework allow key preprocessing steps such as peak alignment, normalization, or dimensionality reduction to be tailored to specific problems. The mQTL.NMR package is freely available with its source code through the Comprehensive R/Bioconductor repository and its own website ( http://www.ican-institute.org/tools/ ). It represents a significant advance to facilitate untargeted metabolomic data processing and quantitative analysis and their genetic mapping. PMID:25803548

  15. High-resolution 1H NMR in solids with multiple-pulse sequences and magic-angle sample spinning at 270 MHz

    NASA Astrophysics Data System (ADS)

    Scheler, G.; Haubenreisser, U.; Rosenberger, H.

    A probe suitable for 270-MHz 1H NMR in solids is described, using the combination of the phase-error-compensated WAHUHA multiple-pulse cycle and magic-angle sample spinning (MAS). The experimental results obtained at this frequency are compared with measurements at 60 MHz. Because of the increase of frequency the spectral resolution is improved by a factor of about 5. For a variety of organic and inorganic substances the resolution varies from 0.3 ppm in polycrystalline adamantane to about 2 ppm, sufficient to resolve resonance signals of protons of different molecular groups, such as NH 3, NH 4, olefinic, aromatic, and aliphatic protons. Averaged chemical shifts of a series of selected hydrogen-bonded powder samples are discussed. The residual linewidths were found to be due predominantly to second-order residual dipolar broadening, the cross term between resonance offset and dipolar interaction, nonresolved chemical shifts, and interactions of protons with nuclei which have a strong quadrupolar moment. The resolution is expected to be increased by combining the high-field MAS experiments and more effective multiple-pulse sequences, e.g., the 24-pulse cycle developed recently by Burum and Rhim.

  16. Targeted and nontargeted wine analysis by (1)h NMR spectroscopy combined with multivariate statistical analysis. Differentiation of important parameters: grape variety, geographical origin, year of vintage.

    PubMed

    Godelmann, Rolf; Fang, Fang; Humpfer, Eberhard; Schütz, Birk; Bansbach, Melanie; Schäfer, Hartmut; Spraul, Manfred

    2013-06-12

    The authenticity, the grape variety, the geographical origin, and the year of vintage of wines produced in Germany were investigated by (1)H NMR spectroscopy in combination with several steps of multivariate data analysis including principal component analysis (PCA), linear discrimination analysis (LDA), and multivariate analysis of variance (MANOVA) together with cross-validation (CV) embedded in a Monte Carlo resampling approach (MC) and others. A total of about 600 wines were selected and carefully collected from five wine-growing areas in the southern and southwestern parts of Germany. Simultaneous saturation of the resonances of water and ethanol by application of a low-power eight-frequency band irradiation using shaped pulses allowed for high receiver gain settings and hence optimized signal-to-noise ratios. Correct prediction of classification of the grape varieties of Pinot noir, Lemberger, Pinot blanc/Pinot gris, Müller-Thurgau, Riesling, and Gewürztraminer of 95% in the wine panel was achieved. The classification of the vintage of all analyzed wines resulted in correct predictions of 97 and 96%, respectively, for vintage 2008 (n = 318) and 2009 (n = 265). The geographic origin of all wines from the largest German wine-producing regions, Rheinpfalz, Rheinhessen, Mosel, Baden, and Württemberg, could be predicted 89% correctly on average. Each NMR spectrum could be regarded as the individual "fingerprint" of a wine sample, which includes information about variety, origin, vintage, physiological state, technological treatment, and others. PMID:23682581

  17. The bilateral action between EQ14-2-14 gemini surfactant and bovine serum albumin by DPI and 1H NMR

    NASA Astrophysics Data System (ADS)

    Wu, Gang; Jiang, Xiaohui; Zhou, Limei; Yang, Lijun; Wang, Ya; Xia, Guangqiang; Chen, Zhengjun; Duan, Ming

    2013-08-01

    Gemini surfactant diglycol bis-N-tetradecyl nicotinate dibromide (designed as EQ14-2-14) has been synthesized. The interaction between EQ14-2-14 and bovine serum albumin (BSA) was studied by dual polarization interferometry (DPI), proton nuclear magnetic resonance spectroscopy (1H NMR), Fourier transform infrared spectroscopy (FTIR) and molecular docking. Owing to the binding of EQ14-2-14, the thickness and mass of BSA increased; refractive index (RI) and density firstly raised and then tended to a plateau. In addition, a decrease of α-helix was observed from 54.01% to 31.56% with an increase in random structure from 7.86% to 21.76%. Due to BSA intertwining, the proton resonance signals of EQ14-2-14 shifted up-field and relaxation time decreased with increasing concentration of BSA. The study of molecular docking indicated that EQ14-2-14 embedded into subdomain II of BSA by π-π stacking between the electron-deficit pyridinium rings in EQ14-2-14 and the electron-abundant pyrrole ring in Trp residues of BSA, by hydrogen bonding and by hydrophobic interaction. Therefore the present work offers a whole view of the interaction of BSA with a new gemini surfactant.

  18. Inhomogeneous 1H NMR spin-lattice relaxation in the organic superconductor kappa-(BEDT-TTF)2Cu[N(CN)2]Br

    NASA Astrophysics Data System (ADS)

    Gezo, Joseph Christopher

    The two-dimensional superconductors based on the organic molecule "ET" have been an active area of research since their discovery over two decades ago. The member of this family with the highest critical temperature, kappa-(ET)2Cu[N(CN)2]Br ( Tc=11.7 K), has seen renewed interest since the observation of an anomalous Nernst signal by Nam et al in 2007 [51]. A similar effect was seen earlier by Ong's group in some of the high-temperature cuprate superconductors by [78,84]. This is interpreted to be evidence of a picture of superconductivity in which the resistive transition is driven by thermal fluctuations in the phase of the superconducting order parameter. Below Tc, these fluctuations take the form of bound vortex-antivortex pairs that have no long-range effect on the phase. At Tc, they undergo a Kosterlitz-Thouless unbinding transition; the unbound vortices destroy long-range phase coherence. Previously reported proton NMR measurements on this material have shown a high sensitivity to vortex motion, but reported no interesting behavior above the phase transition [15,25,42]. In this thesis, we revisit the 1H NMR properties of kappa-(ET)2Cu[N(CN)2]Br, paying specific attention to the spin-lattice relaxation, to look for some fingerprint of the phenomenon observed by Nam et al.

  19. Hydrogen motion and local structure of metals in β-Ti1-yVyHx as studied by 1H NMR

    NASA Astrophysics Data System (ADS)

    Ueda, Takahiro; Hayashi, Shigenobu; Hayamizu, Kikuko

    1993-09-01

    Hydrogen motion in β-Ti1-yVyHx (y=0.2, 0.4, 0.6, and 0.8; x~1) alloys was studied by 1H NMR, with which the temperature and frequency dependences of proton spin-lattice relaxation times (T1) were measured over the temperature range 105-400 K and at frequencies 9, 22.5, 52, and 90 MHz. The temperature dependences of T1 change systematically with the metal composition; with a decrease in the concentration of V, the minimum value of T1 increases and the temperature at which T1 is minimized shifts to the higher-temperature side. These results are analyzed with two-site jumps of a proton between unequal potential wells, in which Brouwer's model is assumed to describe local structure of the alloys. Good agreement between the experimental and calculated T1 values is given by this treatment, unlike the isotropic diffusion model. The following three parameters are used for the calculation: activation energies for Ti and V are ETi=16 and EV=9.5 kJ/mol, respectively, and the frequency prefactor is τ0=1.5×10-11 s for 0.4<=y<=0.8. The obtained ETi and EV values agree with those of pure metal hydrides such as TiHx and VHx, respectively.

  20. Conformational studies of human des-trp/sup 1/,Nle/sup 12/-minigastrin in water-trifluoroethanol mixtures by /sup 1/H NMR and circular dichroism

    SciTech Connect

    Mammi, S.; Mammi, N.J.; Peggion, E.

    1988-02-23

    The /sup 1/H NMR spectrum of the title peptide, H-Leu-(Glu)/sub 5/-Ala-Tyr-Gly-Trp-Nle-Asp-Phe-NH/sub 2/, in 90% H/sub 2/O/10% D/sub 2/O was assigned by two-dimensional methods, and the displacement of the proton resonances upon addition of 2,2,2-trifluoroethanol (TFE) was followed. This permitted the assignment of the spectrum in 90% TFE/10% D/sub 2/O. While the water conformation of the minigastrin analog is random, the CD spectrum indicates that an ordered structure is present in TFE. Variable-temperature NMR data in this medium show that six amide protons have low temperature coefficients, two of the five Glu's, Trp, Nle, Asp, and Phe. These results were interpreted in terms of an ..cap alpha..-helical stretch comprising the Leu and the five Glu residues and a 3/sub 10/-helix initiated by a ..beta..-turn at the sequence -Ala-Tyr-Gly-Trp-. Both CD and NMR data at different solvent compositions show two regions of conformational change, between 20 and 25% water and above 60% water.

  1. α-Glucosidase inhibition and antioxidant activity of an oenological commercial tannin. Extraction, fractionation and analysis by HPLC/ESI-MS/MS and (1)H NMR.

    PubMed

    Muccilli, Vera; Cardullo, Nunzio; Spatafora, Carmela; Cunsolo, Vincenzo; Tringali, Corrado

    2017-01-15

    Two batches of the oenological tannin Tan'Activ R, (toasted oak wood - Quercus robur), were extracted with ethanol. A fractionation on XAD-16 afforded four fractions for each extract. Extracts and fractions were evaluated for antioxidant activity (DPPH), polyphenol content (GAE) and yeast α-glucosidase inhibitory activity. Comparable results were obtained for both columns, fractions X1B and X2B showing the highest antioxidant activity. Fractions X1C and X2C notably inhibited α-glucosidase, with IC50=9.89 and 8.05μg/mL, respectively. Fractions were subjected to HPLC/ESI-MS/MS and (1)H NMR analysis. The main phenolic constituents of both X1B and X2B were a monogalloylglucose isomer (1), a HHDP-glucose isomer (2), castalin (3) gallic acid (4), vescalagin (5), and grandinin (or its isomer roburin E, 6). X1C and X2C showed a complex composition, including non-phenolic constituents. Fractionation of X2C gave a subfraction, with enhanced α-glucosidase inhibitory activity (IC50=6.15μg/mL), with castalagin (7) as the main constituent. PMID:27542449

  2. 1H NMR studies of maltose, maltoheptaose, alpha-, beta-, and gamma-cyclodextrins, and complexes in aqueous solutions with hydroxy protons as structural probes.

    PubMed

    Bekiroglu, Somer; Kenne, Lennart; Sandström, Corine

    2003-03-01

    The (1)H NMR chemical shifts, coupling constants, temperature coefficients, and exchange rates have been measured for the hydroxy protons of aqueous solutions of alpha-, beta-, and gamma-cyclodextrins, maltose, and maltoheptaose. In cyclodextrins (CDs), the high chemical shift of the O(3)H signal and its small (3)J(OH,CH) value suggest that O(3)H is involved in a hydrogen bond. The small temperature coefficients and rate of exchange values of O(2)H and O(3)H confirm the involvement of O(3)H in hydrogen bonding and indicate that O(2)H is the hydrogen bond partner. In maltose, two distinct NMR signals with two different vicinal coupling constants are found for O(2')H. A cross-peak in the ROESY spectrum indicates chemical exchange between the O(2')H and O(3)H protons. The existence of two distinct NMR signals with different J values for O(2')H shows the influence of anomeric configuration on the O(2')H-O(3)H interaction. The effect of complexation with methyl benzoate, adamantane-1-carboxylic acid, adamantane-1-ol, and l- and d-tryptophane on the NMR spectra of the hydroxy protons of alpha-, beta-, and gamma-cyclodextrins and of maltose has been investigated. No significant spectral changes were observed upon addition of methyl benzoate and adamantane-1-carboxylic acid. The addition of adamantane-1-ol resulted in an upfield shift and a strong broadening of the O(2)H signal from alpha-CD, and a small temperature coefficient was measured upon complexation. The O(2)H and O(3)H signals in beta-CD were broadened and shifted downfield upon addition of l- and d-tryptophane. PMID:12608778

  3. In Vitro Monitoring of Total Choline Levels in a Bioartificial Pancreas: 1H NMR Spectroscopic Studies of the Effects of Oxygen Level

    NASA Astrophysics Data System (ADS)

    Long, Robert C.; Papas, Klearchos K.; Sambanis, Athanassios; Constantinidis, Ioannis

    2000-09-01

    This investigation implements specifically designed solvent-suppressed adiabatic pulses whose properties make possible the long-term monitoring of 1H NMR detectable metabolites from alginate/poly-l-lysine/alginate (APA)-encapsulated βTC3 cells. Our encapsulated preparations were maintained in a perfusion bioreactor for periods exceeding 30 days. During this prolonged cultivation period, the cells were exposed to repetitive hypoxic episodes of 4 and 24 h. The ratio of the total choline signal (3.20 ppm) to the reference signal (observed at 0.94 ppm assigned to isoleucine, leucine, and valine) decreased by 8-10% for the 4-h and by 20-32% for the 24-h episodes and returned to its prehypoxic level upon reoxygenation. The decrease in the mean value of total choline to reference signal ratio for three 4-h and two 24-h episodes in two different cultures was highly significant (P < 0.01). The rate of recovery by this ratio was slower than the rates of recovery by oxygen consumption, lactate production, or glucose consumption. A step-up in oxygen level led to a new, higher value for the total choline to reference ratio. From spectra of extracts at 400 MHz, it was determined that 63.6% of the total choline signal is due to intracellular phosphorylcholine. Therefore, it is inferred that the observed changes in total choline signal are linked to an oxygen level dependence of the intracellular phosphorylcholine. Several possible mechanisms in which oxygen may influence phosphorylcholine metabolism are suggested. In addition, the implications of these findings to the development of a noninvasive monitoring method for tissue-engineered constructs composed of encapsulated cells are discussed.

  4. X-ray guided 1H NMR analysis of pinched cone calix[4]arenes

    NASA Astrophysics Data System (ADS)

    Rashatasakhon, Paitoon; Jaiyu, Arisa; Rojanathanes, Rojrit; Muangsin, Nongnuj; Chaichit, Narongsak; Sukwattanasinitt, Mongkol

    2010-01-01

    The analysis of structural parameters of azobenzene- and stilbene-bridged calix[4]arene obtained from AM1 calculation are in good agreement with those obtained from X-ray crystallography. The bridge longer than 9.0 Å such as p,p- trans-azobenzene and p,p- trans-stilbene cannot be constructed over the narrow rim of calix[4]arene through two ethylene oxide linkers. The m,m-stilbene bridge is the most promising photo switch because its shorter cis stereoisomer (5.85 Å) allows calix[4]arene to assume the perfect cone conformation, whilst its longer trans stereoisomer (8.00 Å) forces calix[4]arene to adapt a pinched cone conformation. The pinched cone conformation has longer distances between the neighbouring phenoxyl groups causing the weaker intramolecular hydrogen bonding and the upfield shifts of the phenolic proton signals to below 7.00 ppm. This upfield shift is useful for quick identification of pinched cone conformation of new calix[4]arene compounds.

  5. (1) H NMR metabolomics analysis of renal cell carcinoma cells: Effect of VHL inactivation on metabolism.

    PubMed

    Cuperlovic-Culf, Miroslava; Cormier, Kevin; Touaibia, Mohamed; Reyjal, Julie; Robichaud, Sarah; Belbraouet, Mehdi; Turcotte, Sandra

    2016-05-15

    Von Hippel-Lindau (VHL) is an onco-suppressor involved in oxygen and energy-dependent promotion of protein ubiquitination and proteosomal degradation. Loss of function mutations of VHL (VHL-cells) result in organ specific cancers with the best studied example in renal cell carcinomas. VHL has a well-established role in deactivation of hypoxia-inducible factor (HIF-1) and in regulation of PI3K/AKT/mTOR activity. Cell culture metabolomics analysis was utilized to determined effect of VHL and HIF-1α or HIF-2α on metabolism of renal cell carcinomas (RCC). RCC cells were stably transfected with VHL or shRNA designed to silence HIF-1α or HIF-2α genes. Obtained metabolic data was analysed qualitatively, searching for overall effects on metabolism as well as quantitatively, using methods developed in our group in order to determine specific metabolic changes. Analysis of the effect of VHL and HIF silencing on cellular metabolic footprints and fingerprints provided information about the metabolic pathways affected by VHL through HIF function as well as independently of HIF. Through correlation network analysis as well as statistical analysis of significant metabolic changes we have determined effects of VHL and HIF on energy production, amino acid metabolism, choline metabolism as well as cell regulation and signaling. VHL was shown to influence cellular metabolism through its effect on HIF proteins as well as by affecting activity of other factors. PMID:26620126

  6. Communication: Molecular dynamics and {sup 1}H NMR of n-hexane in liquid crystals

    SciTech Connect

    Weber, Adrian C. J.; Burnell, E. Elliott; Meerts, W. Leo; Lange, Cornelis A. de; Dong, Ronald Y.; Muccioli, Luca Pizzirusso, Antonio Zannoni, Claudio

    2015-07-07

    The NMR spectrum of n-hexane orientationally ordered in the nematic liquid crystal ZLI-1132 is analysed using covariance matrix adaptation evolution strategy (CMA-ES). The spectrum contains over 150 000 transitions, with many sharp features appearing above a broad, underlying background signal that results from the plethora of overlapping transitions from the n-hexane as well as from the liquid crystal. The CMA-ES requires initial search ranges for NMR spectral parameters, notably the direct dipolar couplings. Several sets of such ranges were utilized, including three from MD simulations and others from the modified chord model that is specifically designed to predict hydrocarbon-chain dipolar couplings. In the end, only inaccurate dipolar couplings from an earlier study utilizing proton-proton double quantum 2D-NMR techniques on partially deuterated n-hexane provided the necessary estimates. The precise set of dipolar couplings obtained can now be used to investigate conformational averaging of n-hexane in a nematic environment.

  7. Solid state 1H NMR studies of cell wall materials of potatoes

    NASA Astrophysics Data System (ADS)

    Tang, Huiru; Belton, Peter S.; Ng, Annie; Waldron, Keith W.; Ryden, Peter

    1999-04-01

    Cell wall materials from potatoes ( Solanum tuberosum) prepared by two different methods have been studied using NMR proton relaxation times. Spin lattice relaxation in both the rotating and laboratory frames as well as transverse relaxation have been measured over a range of temperatures and hydration levels. It was observed that the sample prepared using a DMSO extraction showed anomalous behaviour of spin lattice relaxation in the laboratory frame probably due to residual solvent in the sample. Spin lattice relaxation in the laboratory frame is the result of hydroxymethyl rotation and another unidentified high frequency motion. In the rotating frame relaxation is adequately explained by hydroxymethyl rotation alone. In neither experiment is methyl group rotation observed, calculation suggests that this is due to the low density of methyl groups in the sample. Non-freezing water in potato cell walls, α-cellulose and pectin was found about 0.2, 0.04 and 0.18 g per gram dry matter, indicating preferable hydration of pectin compared to cellulose. The effects of hydration are most noticeable in the measurements that reflect low frequency motions, particularly transverse relaxation, where both second moments and the relative intensity of signals arising from immobile material are reduced by hydration.

  8. Choosing the best molecular precursor to prepare Li4Ti5O12 by the sol-gel method using (1)H NMR: evidence of [Ti3(OEt)13](-) in solution.

    PubMed

    García-Herbosa, Gabriel; Aparicio, Mario; Mosa, Jadra; Cuevas, José V; Torroba, Tomás

    2016-09-21

    (1)H NMR spectroscopy at 400 MHz in toluene-d8 of evaporated mixtures of lithium ethoxide and titanium(iv) isopropoxide in ethanol, used to prepare the spinel Li4Ti5O12 by the sol-gel method, may help clarify why the atomic ratio 5Li : 5Ti and not 4Li : 5Ti is the right choice to obtain the pure phase when performing hydrolysis at room temperature. The mixtures xLiOEt/yTi(OPr(i))4 in ethanol undergo alcohol exchange at room temperature, and the evaporated residues contain double lithium-titanium ethoxide [LiTi3(OEt)13] rather than simple mixtures of single metal alkoxides; this is of great relevance to truly understanding the chemistry and structural changes in the sol-gel process. Detailed inspection of the (1)H and (13)C VT NMR spectra of mixtures with different Li/Ti atomic ratios unequivocally shows the formation of [LiTi3(OEt)13] in a solution at low temperature. The methylene signals of free lithium ethoxide and Li[Ti3(OEt)13] coalesce at 20 °C when the atomic ratio is 5 : 5; however, the same coalescence is only observed above 60 °C when the atomic ratio is 4 : 5. We suggest that the highest chemical equivalence observed by (1)H NMR spectroscopy achieved through chemical exchange of ethoxide groups involves the highest microscopic structural homogeneity of the sol precursor and will lead to the best gel after hydrolysis. Variable temperature (1)H NMR spectra at 400 MHz of variable molar ratios of LiOEt/Ti(OPr(i))4 are discussed to understand the structural features of the sol precursor. While the precursor with the atomic ratio 5Li : 5Ti shows no signal of free LiOEt at 20 °C, both 4Li : 5Ti and 7Li : 5Ti show free LiOEt at 20 °C in their (1)H NMR spectra, indicating that the molar ratio 5Li : 5Ti gives the maximum rate of chemical exchange. DFT calculations have been performed to support the structure of the anion [Ti3(OEt)13](-) at room temperature. PMID:27523928

  9. Change of translational-rotational coupling in liquids revealed by field-cycling 1H NMR

    NASA Astrophysics Data System (ADS)

    Meier, R.; Schneider, E.; Rössler, E. A.

    2015-01-01

    Applying the field-cycling nuclear magnetic resonance technique, the frequency dependence of the 1H spin-lattice relaxation rate, R 1 ω = T1 - 1 ω , is measured for propylene glycol (PG) which is increasingly diluted with deuterated chloroform. A frequency range of 10 kHz-20 MHz and a broad temperature interval from 220 to about 100 K are covered. The results are compared to those of experiments, where glycerol and o-terphenyl are diluted with their deuterated counter-part. Reflecting intra- as well as intermolecular relaxation, the dispersion curves R 1 ω , x (x denotes mole fraction PG) allow to extract the rotational time constant τrot(T, x) and the self-diffusion coefficient D(T, x) in a single experiment. The Stokes-Einstein-Debye (SED) relation is tested in terms of the quantity D(T, x) τrot(T, x) which provides a measure of an effective hydrodynamic radius or equivalently of the spectral separation of the translational and the rotational relaxation contribution. In contrast to o-terphenyl, glycerol and PG show a spectral separation much larger than suggested by the SED relation. In the case of PG/chloroform mixtures, not only an acceleration of the PG dynamics is observed with increasing dilution but also the spectral separation of rotational and translational relaxation contributions continuously decreases. Finally, following a behavior similar to that of o-terphenyl already at about x = 0.6; i.e., while D(T, x) τrot(T, x) in the mixture is essentially temperature independent, it strongly increases with x signaling thus a change of translational-rotational coupling. This directly reflects the dissolution of the hydrogen-bond network and thus a change of solution structure.

  10. Selective Detection of 1H NMR Resonances of CH n Groups Using a Heteronuclear Maximum-Quantum Filter and Pulsed Field Gradients

    NASA Astrophysics Data System (ADS)

    Liu, M.; Farrant, R. D.; Nicholson, J. K.; Lindon, J. C.

    A number of approaches are described for the provision of separate one-dimensional 1H NMR spectra of CH, CH 2, and CH 3 groups utilizing the natural-abundance 13C spins and based upon the selection of the maximum multiple-quantum coherences of the various groups, This sequence is termed edited maximum-quantum proton spectroscop y (MAXY) spectroscopy, The replacement of phase cycling with the application of z magnetic field gradient pulses is also demonstrated, The editing approach is demonstrated using the 1H NMR spectrum of dexamethasone in DMSO- d6 solution, Extension to a complex mixture biofluid is exemplified by the CH 3-only 1H NMR spectrum of human seminal plasma. This aid to the assignment of endogenous metabolite resonances is demonstrated to result in dramatic spectral simplification.

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

    PubMed

    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. PMID:27596391

  12. Toxicometabolomics approach to urinary biomarkers for mercuric chloride (HgCl{sub 2})-induced nephrotoxicity using proton nuclear magnetic resonance ({sup 1}H NMR) in rats

    SciTech Connect

    Kim, Kyu-Bong; Um, So Young; Chung, Myeon Woo; Jung, Seung Chul; Oh, Ji Seon; Kim, Seon Hwa; Na, Han Sung; Lee, Byung Mu; Choi, Ki Hwan

    2010-12-01

    The primary objective of this study was to determine and characterize surrogate biomarkers that can predict nephrotoxicity induced by mercuric chloride (HgCl{sub 2}) using urinary proton nuclear magnetic resonance ({sup 1}H NMR) spectral data. A procedure for {sup 1}H NMR urinalysis using pattern recognition was proposed to evaluate nephrotoxicity induced by HgCl{sub 2} in Sprague-Dawley rats. HgCl{sub 2} at 0.1 or 0.75 mg/kg was administered intraperitoneally (i.p.), and urine was collected every 24 h for 6 days. Animals (n = 6 per group) were sacrificed 3 or 6 days post-dosing in order to perform clinical blood chemistry tests and histopathologic examinations. Urinary {sup 1}H NMR spectroscopy revealed apparent differential clustering between the control and HgCl{sub 2} treatment groups as evidenced by principal component analysis (PCA) and partial least square (PLS)-discriminant analysis (DA). Time- and dose-dependent separation of HgCl{sub 2}-treated animals from controls was observed by PCA of {sup 1}H NMR spectral data. In HgCl{sub 2}-treated rats, the concentrations of endogenous urinary metabolites of glucose, acetate, alanine, lactate, succinate, and ethanol were significantly increased, whereas the concentrations of 2-oxoglutarate, allantoin, citrate, formate, taurine, and hippurate were significantly decreased. These endogenous metabolites were selected as putative biomarkers for HgCl{sub 2}-induced nephrotoxicity. A dose response was observed in concentrations of lactate, acetate, succinate, and ethanol, where severe disruption of the concentrations of 2-oxoglutarate, citrate, formate, glucose, and taurine was observed at the higher dose (0.75 mg/kg) of HgCl{sub 2}. Correlation of urinary {sup 1}H NMR PLS-DA data with renal histopathologic changes suggests that {sup 1}H NMR urinalysis can be used to predict or screen for HgCl{sub 2}-induced nephrotoxicity{sub .}

  13. Solution structure of Ln(III) complexes with macrocyclic ligands through theoretical evaluation of 1H NMR contact shifts.

    PubMed

    Rodríguez-Rodríguez, Aurora; Esteban-Gómez, David; de Blas, Andrés; Rodríguez-Blas, Teresa; Botta, Mauro; Tripier, Raphaël; Platas-Iglesias, Carlos

    2012-12-17

    Herein, we present a new approach that combines DFT calculations and the analysis of Tb(III)-induced (1)H NMR shifts to quantitatively and accurately account for the contact contribution to the paramagnetic shift in Ln(III) complexes. Geometry optimizations of different Gd(III) complexes with macrocyclic ligands were carried out using the hybrid meta-GGA TPSSh functional and a 46 + 4f(7) effective core potential (ECP) for Gd. The complexes investigated include [Ln(Me-DODPA)](+) (H(2)Me-DODPA = 6,6'-((4,10-dimethyl-1,4,7,10-tetraazacyclododecane-1,7-diyl)bis(methylene))dipicolinic acid, [Ln(DOTA)(H(2)O)](-) (H(4)DOTA = 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetate), [Ln(DOTAM)(H(2)O)](3+) (DOTAM = 1,4,7,10- tetrakis[(carbamoyl)methyl]-1,4,7,10-tetraazacyclododecane), and related systems containing pyridyl units (Ln = Gd, Tb). Subsequent all-electron relativistic calculations based on the DKH2 approximation, or small-core ECP calculations, were used to compute the (1)H hyperfine coupling constants (HFCCs) at the ligand nuclei (A(iso) values). The calculated A(iso) values provided direct access to contact contributions to the (1)H NMR shifts of the corresponding Tb(III) complexes under the assumption that Gd and Tb complexes with a given ligand present similar HFCCs. These contact shifts were used to obtain the pseudocontact shifts, which encode structural information as they depend on the position of the nucleus with respect to the lanthanide ion. An excellent agreement was observed between the experimental and calculated pseudocontact shifts using the DFT-optimized geometries as structural models of the complexes in solution, which demonstrates that the computational approach used provides (i) good structural models for the complexes, (ii) accurate HFCCs at the ligand nuclei. The methodology presented in this work can be classified in the context of model-dependent methods, as it relies on the use of a specific molecular structure obtained from DFT

  14. Metastatic Melanoma Induced Metabolic Changes in C57BL/6J Mouse Stomach Measured by 1H NMR Spectroscopy

    DOE PAGESBeta

    Hu, M; Wang, Xiliang

    2014-12-05

    Melanoma is a malignant tumor of melanocytes with high capability of invasion and rapid metastasis to other organs. Malignant melanoma is the most common metastatic malignancy found in gastrointestinal tract (GI). To the best of our knowledge, previous studies of melanoma in gastrointestinal tract are all clinical case reports. In this work, 1H NMR-based metabolomics approach is used to investigate the metabolite profiles differences of stomach tissue extracts of metastatic B16-F10 melanoma in C57BL/6J mouse and search for specific metabolite biomarker candidates. Principal Component Analysis (PCA), an unsupervised multivariate data analysis method, is used to detect possible outliers, while Orthogonalmore » Projection to Latent Structure (OPLS), a supervised multivariate data analysis method, is employed to evaluate important metabolites responsible for discriminating the control and the melanoma groups. Both PCA and OPLS results reveal that the melanoma group can be well separated from its control group. Among the 50 identified metabolites, it is found that the concentrations of 19 metabolites are statistically and significantly changed with the levels of O-phosphocholine and hypoxanthine down-regulated while the levels of isoleucine, leucine, valine, isobutyrate, threonine, cadaverine, alanine, glutamate, glutamine, methionine, citrate, asparagine, tryptophan, glycine, serine, uracil, and formate up-regulated in the melanoma group. These significantly changed metabolites are associated with multiple biological pathways and may be potential biomarkers for metastatic melanoma in stomach.« less

  15. Metastatic Melanoma Induced Metabolic Changes in C57BL/6J Mouse Stomach Measured by 1H NMR Spectroscopy

    SciTech Connect

    Hu, M; Wang, Xiliang

    2014-12-05

    Melanoma is a malignant tumor of melanocytes with high capability of invasion and rapid metastasis to other organs. Malignant melanoma is the most common metastatic malignancy found in gastrointestinal tract (GI). To the best of our knowledge, previous studies of melanoma in gastrointestinal tract are all clinical case reports. In this work, 1H NMR-based metabolomics approach is used to investigate the metabolite profiles differences of stomach tissue extracts of metastatic B16-F10 melanoma in C57BL/6J mouse and search for specific metabolite biomarker candidates. Principal Component Analysis (PCA), an unsupervised multivariate data analysis method, is used to detect possible outliers, while Orthogonal Projection to Latent Structure (OPLS), a supervised multivariate data analysis method, is employed to evaluate important metabolites responsible for discriminating the control and the melanoma groups. Both PCA and OPLS results reveal that the melanoma group can be well separated from its control group. Among the 50 identified metabolites, it is found that the concentrations of 19 metabolites are statistically and significantly changed with the levels of O-phosphocholine and hypoxanthine down-regulated while the levels of isoleucine, leucine, valine, isobutyrate, threonine, cadaverine, alanine, glutamate, glutamine, methionine, citrate, asparagine, tryptophan, glycine, serine, uracil, and formate up-regulated in the melanoma group. These significantly changed metabolites are associated with multiple biological pathways and may be potential biomarkers for metastatic melanoma in stomach.

  16. Intervention effects of puerarin on blood stasis in rats revealed by a (1)H NMR-based metabonomic approach.

    PubMed

    Zou, Zhong Jie; Liu, Zhong Hua; Gong, Meng Juan; Han, Bin; Wang, Shu Mei; Liang, Sheng Wang

    2015-03-15

    Puerarin possesses a wide spectrum of biological activities including ameliorating effects on blood stasis, but the definite mechanism of this effect is still not known. In this study, a (1)H NMR-based plasma and urinary metabonomic approach was applied to comprehensively and holistically investigate the therapeutic effects of puerarin on blood stasis and its underlying mechanisms. Puerarin was injected intraperitoneally once daily for consecutive 7 days. The blood stasis rat model was established by placing the rats in ice-cold water during the time interval between two injections of adrenaline. With pattern recognition analysis, a clear separation of blood stasis model group and healthy control group was achieved and puerarin pretreatment group was located much closer to the control group than the model group, which was consistent with results of hemorheology studies. 15 and 10 potential biomarkers associated with blood stasis in plasma and urine, respectively, which were mainly involved in energy metabolism, lipid and membrane metabolisms, amino acid metabolism and gut microbiota metabolism, were identified. Puerarin could prevent blood stasis through partially regulating the disturbed metabolic pathways. This work highlights that metabonomics is a valuable tool for studying the essence of blood stasis as well as evaluating the efficacy of the corresponding drug treatment. PMID:25837270

  17. Ion-pair assisted extraction followed by (1)H NMR determination of biogenic amines in food and biological matrices.

    PubMed

    Chatzimitakos, T; Exarchou, V; Ordoudi, S A; Fiamegos, Y; Stalikas, C

    2016-07-01

    A selective method for the extraction and determination of six biogenic amines (BAs) by NMR is presented. Briefly, BAs are extracted into an organic solvent via the use of an ion pairing agent, followed by a back extraction in D2O in order to acquire the (1)H NMR spectra. The method is studied with respect to the critical experimental parameters and is successfully applied to selected food substrates (dark chocolate, banana, gouda cheese) and biological samples (urine and blood plasma) signifying its potential as an alternative tool for BAs determination. Accurate and precise results are consistently achieved with all matrixes studied. The calculated limits of detection and limits of quantitation were found to be in the ranges 0.05-0.13μg/mL and 0.14-0.38μg/mL, respectively, for biological samples while for food samples they were in the ranges 2.25-6.25μg/g and 6.75-18.7μg/g, respectively. PMID:26920317

  18. 1H NMR studies distinguish the water soluble metabolomic profiles of untransformed and RAS-transformed cells

    PubMed Central

    Marks, Vered; Munoz, Anisleidys; Rai, Priyamvada

    2016-01-01

    Metabolomic profiling is an increasingly important method for identifying potential biomarkers in cancer cells with a view towards improved diagnosis and treatment. Nuclear magnetic resonance (NMR) provides a potentially noninvasive means to accurately characterize differences in the metabolomic profiles of cells. In this work, we use 1H NMR to measure the metabolomic profiles of water soluble metabolites extracted from isogenic control and oncogenic HRAS-, KRAS-, and NRAS-transduced BEAS2B lung epithelial cells to determine the robustness of NMR metabolomic profiling in detecting differences between the transformed cells and their untransformed counterparts as well as differences among the RAS-transformed cells. Unique metabolomic signatures between control and RAS-transformed cell lines as well as among the three RAS isoform-transformed lines were found by applying principal component analysis to the NMR data. This study provides a proof of principle demonstration that NMR-based metabolomic profiling can robustly distinguish untransformed and RAS-transformed cells as well as cells transformed with different RAS oncogenic isoforms. Thus, our data may potentially provide new diagnostic signatures for RAS-transformed cells. PMID:27330862

  19. 1H NMR structural and thermodynamical analysis of the hetero-association of daunomycin and novatrone in aqueous solution

    NASA Astrophysics Data System (ADS)

    Veselkov, A. N.; Evstigneev, M. P.; Rozvadovskaya, A. O.; Hernandez Santiago, A.; Zubchenok, O. V.; Djimant, L. N.; Davies, D. B.

    2004-09-01

    The complexation of antitumour antibiotics novatrone (NOV) and daunomycin (DAU) in aqueous solution has been studied by one- and two-dimensional 1H-NMR spectroscopy (500 MHz) in order to elucidate the probable molecular mechanism of the action of aromatic antitumour drugs in combination chemotherapy. The equilibrium reaction constants, thermodynamical parameters (Δ H, Δ S) of hetero-association of NOV with DAU and the limiting values of proton chemical shifts of the molecules in the hetero-complexes have been determined from the experimental concentration and temperature dependences of proton chemical shifts of the aromatic molecules. The most favourable structure of the 1:1 NOV-DAU hetero-association complex has been determined using both the molecular mechanics methods (X-PLOR software) and the limiting values of proton chemical shifts of the molecules. The obtained results have shown that intermolecular complexes between NOV and DAU molecules are mainly stabilized by stacking interactions of the aromatic chromophores. It is likely that there is an additional stabilization of the NOV-DAU hetero-complexes by intermolecular hydrogen bonds. It is concluded that aromatic molecules of antibiotics may form energetically stable hetero-association complexes in aqueous solution and hence effect their medical-biological (and probably toxic) activity.

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

    NASA Astrophysics Data System (ADS)

    Pawlukojć, A.; Hołderna-Natkaniec, K.; Bator, G.; Natkaniec, I.

    2014-10-01

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

  1. sup 1 H NMR identification of a. beta. -sheet structure and description of folding topology in putidaredoxin

    SciTech Connect

    Pochapsky, T.C.; Ye, Xiao Mei )

    1991-04-23

    Putidaredoxin (Pdx), a 106-residue globular protein consisting of a single polypeptide chain and a (2Fe-2S) cluster, is the physiological reductant of P-450{sub cam}, which in turn catalyzes the monohydroxylation of camphor by molecular oxygen. No crystal structure has been obtained for Pdx or for any closely homologous protein. The application of two-dimensional {sup 1}H NMR methods to the problem of structure determination in Pdx is reported. A {beta}-sheet consisting of five short strands and one {beta}-turn has been identified from distinctive nuclear Overhauser effect patterns. All of the backbone resonances and a majority of the side-chain resonances corresponding to protons in the {beta}-sheet have been assigned sequence specifically. The sheet contains one parallel and three antiparallel strand orientations. Hydrophobic side chains in the {beta}-sheet face primarily toward the protein interior, except for a group of three valine side chains that are apparently solvent exposed. The potential significance of this hydrophobic patch in terms of biological activity is discussed. The folding topology, as determined by the constraints of the {beta}-sheet, is compared with that of other (2Fe-2S) proteins for which folding topologies are known.

  2. 1H NMR-Based Metabolite Profiling of Plasma in a Rat Model of Chronic Kidney Disease

    PubMed Central

    Kim, Ju-Ae; Choi, Hyo-Jung; Kwon, Yong-Kook; Ryu, Do Hyun; Kwon, Tae-Hwan; Hwang, Geum-Sook

    2014-01-01

    Chronic kidney disease (CKD) is characterized by the gradual loss of the kidney function to excrete wastes and fluids from the blood. 1H NMR-based metabolomics was exploited to investigate the altered metabolic pattern in rats with CKD induced by surgical reduction of the renal mass (i.e., 5/6 nephrectomy (5/6 Nx)), particularly for identifying specific metabolic biomarkers associated with early of CKD. Plasma metabolite profiling was performed in CKD rats (at 4- or 8-weeks after 5/6 Nx) compared to sham-operated rats. Principle components analysis (PCA), partial least squares-discriminant analysis (PLS-DA) and orthogonal partial least squares-discriminant analysis (OPLS-DA) score plots showed a significant separation between the groups. The resulting metabolic profiles demonstrated significantly increased plasma levels of organic anions, including citrate, β-hydroxybutyrate, lactate, acetate, acetoacetate, and formate in CKD. Moreover, levels of alanine, glutamine, and glutamate were significantly higher. These changes were likely to be associated with complicated metabolic acidosis in CKD for counteracting systemic metabolic acidosis or increased protein catabolism from muscle. In contrast, levels of VLDL/LDL (CH2)n and N-acetylglycoproteins were decreased. Taken together, the observed changes of plasma metabolite profiles in CKD rats provide insights into the disturbed metabolism in early phase of CKD, in particular for the altered metabolism of acid-base and/or amino acids. PMID:24465563

  3. Data fusion between high resolution (1)H-NMR and mass spectrometry: a synergetic approach to honey botanical origin characterization.

    PubMed

    Spiteri, Marc; Dubin, Elodie; Cotton, Jérôme; Poirel, Marion; Corman, Bruno; Jamin, Eric; Lees, Michèle; Rutledge, Douglas

    2016-06-01

    A data fusion approach was applied to a commercial honey data set analysed by (1)H-nuclear magnetic resonance (NMR) 400 MHz and liquid chromatography-high resolution mass spectrometry (LC-HRMS). The latter was performed using two types of mass spectrometers: an Orbitrap-MS and a time of flight (TOF)-MS. Fifty-six honey samples from four monofloral origins (acacia, orange blossom, lavender and eucalyptus) and multifloral sources from various geographical origins were analysed using the three instruments. The discriminating power of the results was examined by PCA first considering each technique separately, and then combining NMR and LC-HRMS together with or without variable selection. It was shown that the discriminating potential is increased through the data fusion, allowing for a better separation of eucalyptus, orange blossom and lavender. The NMR-Orbitrap-MS and NMR-TOF-MS mid-level fusion models with variable selection were preferred as a good discrimination was obtained with no misclassification observed for the latter. This study opens the path to new comprehensive food profiling approaches combining more than one technique in order to benefit from the advantages of several technologies. Graphical Abstract Data fusion between high resolution 1H-NMR and mass spectrometry. PMID:27086012

  4. 1H NMR spectroscopy of serum reveals unique metabolic fingerprints associated with subtypes of surgically induced osteoarthritis in sheep.

    PubMed

    Maher, Anthony D; Coles, Chantal; White, Jason; Bateman, John F; Fuller, Emily S; Burkhardt, Dan; Little, Christopher B; Cake, Martin; Read, Richard; McDonagh, Matthew B; Rochfort, Simone Jane

    2012-08-01

    Osteoarthritis (OA) is a highly prevalent joint disease. Its slow progressive nature and the correlation between pathological changes and clinical symptoms mean that OA is often well advanced by the time of diagnosis. In the absence of any specific pharmacological treatments, there is a pressing need to develop robust biomarkers for OA. We have adopted a nuclear magnetic resonance (NMR)-based metabolomic strategy to identify molecular responses to surgically induced OA in an animal model. Sheep underwent one of three types of surgical procedure (sham (control), meniscal destabilization, MD or anterior cruciate ligament transaction, ACLT), and for every animal a serum sample was collected both pre- and postoperatively, thus, affording two types of "control" data for comparison. 1D 1H NMR spectra were acquired from each sample at 800 MHz and the digitized spectral data were analyzed using principal components analysis and partial least-squares regression discriminant analysis. Our approach, combined with the study design, allowed us to separate the metabolic responses to surgical intervention from those associated with OA. We were able to identify dimethyl sulfone (DMSO2) as being increased in MD after 4 weeks, while ACLT-induced OA exhibited increased 3-methylhistidine and decreased branched chain amino acids (BCAAs). The findings are discussed in the context of interpretation of metabolomic results in studies of human disease, and the selection of appropriate "control" data sets. PMID:22784358

  5. Metabolite signatures in hydrophilic extracts of mouse lungs exposed to cigarette smoke revealed by 1H NMR metabolomics investigation

    DOE PAGESBeta

    Hu, Jian Z.; Wang, Xuan; Feng, Ju; Webb-Robertson, Bobbie-Jo M.; Waters, Katrina M.; Tilton, Susan C.; Pounds, Joel G.; Corley, Richard A.; Liu, Maili; Hu, Mary Y.

    2015-05-12

    Herein, 1H-NMR metabolomics are carried out to evaluate the changes of metabolites in lungs of mice exposed to cigarette smoke. It is found that the concentrations of adenosine derivatives (i.e. ATP, ADP and AMP), inosine and uridine are significantly fluctuated in the lungs of mice exposed to cigarette smoke compared with those of controls regardless the mouse is obese or regular weight. The decreased ATP, ADP, AMP and elevated inosine predict that the deaminases in charge of adenosine derivatives to inosine derivatives conversion are altered in lungs of mice exposed to cigarette smoke. Transcriptional analysis reveals that the concentrations ofmore » adenosine monophosphate deaminase and adenosine deaminase are different in the lungs of mice exposed to cigarette smoke, confirming the prediction from metabolomics studies. We also found, for the first time, that the ratio of glycerophosphocholine (GPC) to phosphocholine (PC) is significantly increased in the lungs of obese mice compared with regular weight mice. The ratio of GPC/PC is further elevated in the lungs of obese group by cigarette smoke exposure. Since GPC/PC ratio is a known biomarker for cancer, these results may suggest that obese group is more susceptible to lung cancer when exposed to cigarette smoke.« less

  6. 1H-NMR studies on the ternary complexes of rare-earth ions with thenoyltrifluoroacetone and polyethers in dichloromethane.

    PubMed

    Gagabe, Gene Frederick; Satoh, Keiichi; Sawada, Kiyoshi

    2009-07-28

    The structures of the ternary complexes of lanthanoid and yttrium (Ln3+)-thenoyltrifluoroacetonates (tta-) with polyether (POE) in organic phase were investigated by 1H-NMR spectroscopy, where the POEs are crown ethers (18-crown-6 and benzo-18-crown-6) and monodispersed linear polyethers (DEOn: HO-(CH2CH2O-)nC12H25, where n=4, 6, 8). The changes in chemical shift of methylene protons of POE by addition of the adduct complex [Ln(tta)3(POE)] were measured at various Ln3+-to-POE concentration ratios. Chemical shift changes for each proton of POE by the formation of [Ln(tta)3(POE)] were determined. Results revealed that oxygen atoms at the hydroxyl terminal of linear POE have higher tendency to coordinate to the metal ion in [Ln(tta)3] complex. Three (for La3+) or two (for Lu3+ or Y3+) oxygen atoms of the POE coordinate to the metal ion without substitution of tta- ligands to satisfy the metal ion's coordination number of nine or eight, respectively. In the case of 18-membered crown ether complexes, La3+ is incorporated inside the cavity of the POE, displacing one of the three tta- from the inner coordination sphere while the other two remain coordinated to the metal ion. On the other hand, for the adduct of Y3+ complex with crown ether, all three tta- ligands are directly coordinating to the metal ion. PMID:19587993

  7. LC-MS- and (1)H NMR-Based Metabolomic Analysis and in Vitro Toxicological Assessment of 43 Aristolochia Species.

    PubMed

    Michl, Johanna; Kite, Geoffrey C; Wanke, Stefan; Zierau, Oliver; Vollmer, Guenter; Neinhuis, Christoph; Simmonds, Monique S J; Heinrich, Michael

    2016-01-22

    Species of Aristolochia are used as herbal medicines worldwide. They cause aristolochic acid nephropathy (AAN), a devastating disease associated with kidney failure and renal cancer. Aristolochic acids I and II (1 and 2) are considered to be responsible for these nephrotoxic and carcinogenic effects. A wide range of other aristolochic acid analogues (AAAs) exist, and their implication in AAN may have been overlooked. An LC-MS- and (1)H NMR-based metabolomic analysis was carried out on 43 medicinally used Aristolochia species. The cytotoxicity and genotoxicity of 28 Aristolochia extracts were measured in human kidney (HK-2) cells. Compounds 1 and 2 were found to be the most common AAAs. However, AA IV (3), aristolactam I (4), and aristolactam BI (5) were also widespread. No correlation was found between the amounts of 1 or 2 and extract cytotoxicity against HK-2 cells. The genotoxicity and cytotoxicity of the extracts could be linked to their contents of 5, AA D (8), and AA IIIa (10). These results undermine the assumption that 1 and 2 are exclusively responsible for the toxicity of Aristolochia species. Other analogues are likely to contribute to their toxicity and need to be considered as nephrotoxic agents. These findings facilitate understanding of the nephrotoxic mechanisms of Aristolochia and have significance for the regulation of herbal medicines. PMID:26706944

  8. (1)H NMR-based metabolic profiling of liver in chronic unpredictable mild stress rats with genipin treatment.

    PubMed

    Chen, Jian-Li; Shi, Bi-Yun; Xiang, Huan; Hou, Wen-Jing; Qin, Xue-Mei; Tian, Jun-Sheng; Du, Guan-Hua

    2015-11-10

    Genipin, a hydrolyzed metabolite of geniposide extracted from the fruit of Gardenia jasminoides Ellis, has shown promise in alleviating depressive symptoms, however, the antidepressant mechanism of genipin remains unclear and incomprehensive. In this study, the metabolic profiles of aqueous and lipophilic extracts in liver of the chronic unpredictable mild stress (CUMS)-induced rat with genipin treatment were investigated using proton nuclear magnetic resonance ((1)H NMR) spectroscopy coupled with multivariate data analysis. Significant differences in the metabolic profiles of rats in the CUMS model group (MS) and the control group (NS) were observed with metabolic effects including decreasing in choline, glycerol and glycogen, increasing in lactate, alanine and succinate, and a disordered lipid metabolism, while the moderate dose (50mg/kg) of genipin could significantly regulate the concentrations of glycerol, lactate, alanine, succinate and the lipid to their normal levels. These biomakers were involved in metabolism pathways such as glycolysis/gluconeogensis, tricarboxylic acid (TCA) cycle and lipid metabolism, which may be helpful for understanding of antidepressant mechanism of genipin. PMID:26204246

  9. Metastatic Melanoma Induced Metabolic Changes in C57BL/6J Mouse Stomach Measured by 1H NMR Spectroscopy

    PubMed Central

    Wang, X; Hu, M; Liu, M; Hu, JZ

    2015-01-01

    Melanoma is a malignant tumor of melanocytes with high capability of invasion and rapid metastasis to other organs. Malignant melanoma is the most common metastatic malignancy found in Gastrointestinal Tract (GI). In this work, the 1H NMR-based metabolomics approach is used to investigate the metabolite profile differences of stomach tissue extracts of metastatic B16-F10 melanoma and control groups in C57BL/6J mouse and to search for specific metabolite biomarker candidates. Principal Component Analysis (PCA), an unsupervised multivariate data analysis method, is used to detect possible outliers, while Orthogonal Projection to Latent Structure (OPLS), a supervised multivariate data analysis method, is employed to evaluate important metabolites responsible for discriminating the control and the melanoma groups. Both PCA and OPLS results reveal that the melanoma group can be well separated from its control group. Among the 50 identified metabolites, it is found that the concentrations of 19 metabolites are significantly changed with the levels of O-phosphocholine and hypoxanthine down-regulated while the levels of isoleucine, leucine, valine, isobutyrate, threonine, cadaverine, alanine, glutamate, glutamine, methionine, citrate, asparagine, tryptophan, glycine, serine, uracil, and formate up-regulated in the melanoma group. These significantly changed metabolites are associated with multiple biological pathways and may be potential biomarkers for metastatic melanoma in stomach. PMID:26246958

  10. Classification of Coffee Beans by GC-C-IRMS, GC-MS, and (1)H-NMR.

    PubMed

    Arana, Victoria Andrea; Medina, Jessica; Esseiva, Pierre; Pazos, Diego; Wist, Julien

    2016-01-01

    In a previous work using (1)H-NMR we reported encouraging steps towards the construction of a robust expert system for the discrimination of coffees from Colombia versus nearby countries (Brazil and Peru), to assist the recent protected geographical indication granted to Colombian coffee in 2007. This system relies on fingerprints acquired on a 400 MHz magnet and is thus well suited for small scale random screening of samples obtained at resellers or coffee shops. However, this approach cannot easily be implemented at harbour's installations, due to the elevated operational costs of cryogenic magnets. This limitation implies shipping the samples to the NMR laboratory, making the overall approach slower and thereby more expensive and less attractive for large scale screening at harbours. In this work, we report on our attempt to obtain comparable classification results using alternative techniques that have been reported promising as an alternative to NMR: GC-MS and GC-C-IRMS. Although statistically significant information could be obtained by all three methods, the results show that the quality of the classifiers depends mainly on the number of variables included in the analysis; hence NMR provides an advantage since more molecules are detected to obtain a model with better predictions. PMID:27516919

  11. IR, 1H NMR, mass, XRD and TGA/DTA investigations on the ciprofloxacin/iodine charge-transfer complex.

    PubMed

    Refat, Moamen S; El-Hawary, W F; Moussa, Mohamed A A

    2011-05-01

    The charge-transfer complex (CTC) of ciprofloxacin drug (CIP) as a donor with iodine (I(2)) as a sigma acceptor has been studied spectrophotometrically in CHCl(3). At maximum absorption bands, the stoichiometry of CIP:iodine system was found to be 1:1 ratio according to molar ratio method. The essential spectroscopic data like formation constant (K(CT)), molar extinction coefficient (ɛ(CT)), standard free energy (ΔG°), oscillator strength (f), transition dipole moment (μ), resonance energy (R(N)) and ionization potential (I(D)) were estimated. The spectroscopic techniques such as IR, (1)H NMR, mass and UV-vis spectra and elemental analyses (CHN) as well as TG-DTG and DTA investigations were used to characterize the chelating behavior of CIP/iodine charge-transfer complex. The iodine CT interaction was associated with a presence of intermolecular hydrogen bond. The X-ray investigation was carried out to investigate the iodine doping in the synthetic CT complex. PMID:21317025

  12. Classification of Coffee Beans by GC-C-IRMS, GC-MS, and 1H-NMR

    PubMed Central

    Arana, Victoria Andrea; Esseiva, Pierre; Pazos, Diego

    2016-01-01

    In a previous work using 1H-NMR we reported encouraging steps towards the construction of a robust expert system for the discrimination of coffees from Colombia versus nearby countries (Brazil and Peru), to assist the recent protected geographical indication granted to Colombian coffee in 2007. This system relies on fingerprints acquired on a 400 MHz magnet and is thus well suited for small scale random screening of samples obtained at resellers or coffee shops. However, this approach cannot easily be implemented at harbour's installations, due to the elevated operational costs of cryogenic magnets. This limitation implies shipping the samples to the NMR laboratory, making the overall approach slower and thereby more expensive and less attractive for large scale screening at harbours. In this work, we report on our attempt to obtain comparable classification results using alternative techniques that have been reported promising as an alternative to NMR: GC-MS and GC-C-IRMS. Although statistically significant information could be obtained by all three methods, the results show that the quality of the classifiers depends mainly on the number of variables included in the analysis; hence NMR provides an advantage since more molecules are detected to obtain a model with better predictions. PMID:27516919

  13. Computer-assisted assignment of 2D 1H NMR spectra of proteins: basic algorithms and application to phoratoxin B.

    PubMed

    Kleywegt, G J; Boelens, R; Cox, M; Llinás, M; Kaptein, R

    1991-05-01

    A suite of computer programs (CLAIRE) is described which can be of assistance in the process of assigning 2D 1H NMR spectra of proteins. The programs embody a software implementation of the sequential assignment approach first developed by Wüthrich and co-workers (K. Wüthrich, G. Wider, G. Wagner and W. Braun (1982) J. Mol. Biol. 155, 311). After data-abstraction (peakpicking), the software can be used to detect patterns (spin systems), to find cross peaks between patterns in 2D NOE data sets and to generate assignments that are consistent with all available data and which satisfy a number of constraints imposed by the user. An interactive graphics program called CONPAT is used to control the entire assignment process as well as to provide the essential feedback from the experimental NMR spectra. The algorithms are described in detail and the approach is demonstrated on a set of spectra from the mistletoe protein phoratoxin B, a homolog of crambin. The results obtained compare well with those reported earlier based entirely on a manual assignment process. PMID:1841687

  14. Solvent and metal dependent (1)H NMR hyperfine shifts in paramagnetic pentaamminemetal cyanide-bridged mixed-valence complexes.

    PubMed

    Laidlaw, William Michael; Thompson, Amber L; Denning, Robert Gordon

    2013-04-01

    (1)H NMR resonances, in several aprotic solvents, are reported for axial and equatorial ammonias coordinated to a single spin paramagnetic centre in the Robin-Day Class II cyanide-bridged mixed-valence cations [(OC)(5)Cr(μ-CN)M(NH(3))(5)](2+) (M = Ru, Os) as well as in the complex [(OC)(5)Re(μ-CN)Ru(NH(3))(5)](3+), whose synthesis and properties are reported herein. Using the appropriate isotropic hexaammine complex as a reference, the chemical shift difference between the ammonia protons, δ(ax) - δ(eq), is found to be very sensitive to the paramagnetic metal (M), the remote diamagnetic metal (Cr or Re) and also to the donor properties of the solvent (as well as the counter-ion) as a result of hydrogen bonding interactions. The difference varies linearly with the MMCT energy, and in [(OC)(5)Re(μ-CN)Ru(NH(3))(5)](3+) can be tuned from positive (δ(ax) > δ(eq)) to negative (δ(ax) < δ(eq)) through zero (δ(ax) = δ(eq)) by the choice of solvent. This reflects the sign and magnitude of the axial ligand field parameter which is in turn a result of changes in the π-donor-acceptor interactions between the donor-cyanide bridging group and the pentaammine metal unit. PMID:23361503

  15. 1H NMR study of the hetero-association of flavin-mononucleotide with mutagenic dyes: ethidium bromide and proflavine

    NASA Astrophysics Data System (ADS)

    Evstigneev, M. P.; Mukhina, Yu. V.; Davies, D. B.

    The hetero-association of the vitamin B2 derivative, flavin-mononucleotide (FMN), with a mutagenic dye, ethidium bromide (EB) or proflavine (PF), has been studied by 1D and 2D 500 MHz 1H NMR spectroscopy. The variations of proton chemical shifts of both the vitamin and dye as a function of concentration and temperature were analysed in terms of the structural and thermodynamical properties of the FMN-EB and FMN-PF complexes in solution. The structures of the complexes were also investigated by observed intermolecular ROE contacts and molecular mechanics calculations. The results show that the 1 : 1 hetero-association complexes in solution are more stable than the self-association complexes, which is consistent with formation of an intermolecular hydrogen-bond in the hetero-complexes of FMN-EB and FMN-PF. Hence it is possible that the toxicity of aromatic molecules such as EB and PF may be reduced in vitro by the presence of FMN, partly because of the known antimutagenic action of FMN and partly because it has been shown in this work that there is an effective intermolecular association between the mutagens and the vitamin.

  16. (1)H NMR-based metabolomics of Daphnia magna responses after sub-lethal exposure to triclosan, carbamazepine and ibuprofen.

    PubMed

    Kovacevic, Vera; Simpson, André J; Simpson, Myrna J

    2016-09-01

    Pharmaceuticals and personal care products are a class of emerging contaminants that are present in wastewater effluents, surface water, and groundwater around the world. There is a need to determine rapid and reliable bioindicators of exposure and the toxic mode of action of these contaminants to aquatic organisms. (1)H nuclear magnetic resonance (NMR)-based metabolomics in combination with multivariate statistical analysis was used to determine the metabolic profile of Daphnia magna after exposure to a range of sub-lethal concentrations of triclosan (6.25-100μg/L), carbamazepine (1.75-14mg/L) and ibuprofen (1.75-14mg/L) for 48h. Sub-lethal triclosan exposure suggested a general oxidative stress condition and the branched-chain amino acids, glutamine, glutamate, and methionine emerged as potential bioindicators. The aromatic amino acids, serine, glycine and alanine are potential bioindicators for sub-lethal carbamazepine exposure that may have altered energy metabolism. The potential bioindicators for sub-lethal ibuprofen exposure are serine, methionine, lysine, arginine and leucine, which showed a concentration-dependent response. The differences in the metabolic changes were related to the dissimilar modes of toxicity of triclosan, carbamazepine and ibuprofen. (1)H NMR-based metabolomics gave an improved understanding of how these emerging contaminants impact the keystone species D. magna. PMID:26809854

  17. Interaction of phenylbutazone and colchicine in binding to serum albumin in rheumatoid therapy: 1H NMR study

    NASA Astrophysics Data System (ADS)

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

    2009-09-01

    The monitoring of drug concentration in blood serum is necessary in multi-drug therapy. Mechanism of drug binding with serum albumin (SA) is one of the most important factors which determine drug concentration and its transport to the destination tissues. In rheumatoid diseases drugs which can induce various adverse effects are commonly used in combination therapy. Such proceeding may result in the enhancement of those side effects due to drug interaction. Interaction of phenylbutazone and colchicine in binding to serum albumin and competition between them in gout has been studied by proton nuclear magnetic resonance ( 1H NMR) technique. The aim of the study was to determine the low affinity binding sites, the strength and kind of interaction between serum albumin and drugs used in combination therapy. The study of competition between phenylbutazone and colchicine in binding to serum albumin points to the change of their affinity to serum albumin in the ternary systems. This should be taken into account in multi-drug therapy. This work is a subsequent part of the spectroscopic study on Phe-COL-SA interactions [A. Sułkowska, et al., J. Mol. Struct. 881 (2008) 97-106].

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

    SciTech Connect

    Zhang, Ying; Lin, Lianjie; Xu, Yanbin; Lin, Yan; Jin, Yu; Zheng, Changqing

    2013-04-19

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

  19. Metabolite profiling of Curcuma species grown in different regions using 1H NMR spectroscopy and multivariate analysis.

    PubMed

    Jung, Youngae; Lee, Jueun; Kim, Ho Kyoung; Moon, Byeong Cheol; Ji, Yunui; Ryu, Do Hyun; Hwang, Geum-Sook

    2012-12-01

    Curcuma is used to treat skin diseases and colic inflammatory disorders, and in insect repellants and antimicrobial and antidiabetic medications. Two Curcuma species (C. aromatica and C. longa) grown in Jeju-do and Jin-do were used in this study. Methanolic extracts were analyzed by (1)H NMR spectroscopy, and metabolite profiling coupled with multivariate analysis was applied to characterize the differences between species or origin. PCA analysis showed significantly greater differences between species than origins, and the metabolites responsible for the differences were identified. The concentrations of sugars (glucose, fructose, and sucrose) and essential oils (eucalyptol, curdione, and germacrone) were significantly different between the two species. However, the samples from Jeju-do and Jin-do were different mainly in their concentrations of organic acids (fumarate, succinate, acetate, and formate) and sugars. This study demonstrates that NMR-based metabolomics is an efficient method for fingerprinting and determining differences between Curcuma species or those grown in different regions. PMID:23066525

  20. Neurochemical changes in Huntington R6/2 mouse striatum detected by in vivo 1H NMR spectroscopy

    PubMed Central

    Tkac, Ivan; Dubinsky, Janet M.; Keene, C. Dirk; Gruetter, Rolf; Low, Walter C.

    2009-01-01

    The neurochemical profile of the striatum of R6/2 Huntington's disease mice was examined at different stages of pathogenesis using in vivo 1H NMR spectroscopy at 9.4 T. Between 8 and 12 weeks, R6/2 mice exhibited distinct changes in a set of 17 quantifiable metabolites compared with littermate controls. Concentrations of creatine, glycerophosphorylcholine, glutamine and glutathione increased and N-acetylaspartate decreased at 8 weeks. By 12 weeks, concentrations of phosphocreatine, taurine, ascorbate, glutamate, and myo-inositol increased and phophorylethanolamine decreased. These metabolic changes probably reflected multiple processes, including compensatory processes to maintain homeostasis, active at different stages in the development of HD. The observed changes in concentrations suggested impairment of neurotransmission, neuronal integrity and energy demand, and increased membrane breakdown, gliosis, and osmotic and oxidative stress. Comparisons between metabolite concentrations from individual animals clearly distinguished HD transgenics from non-diseased littermates and identified possible markers of disease progression. Metabolic changes in R6/2 striata were distinctly different from those observed previously in the quinolinic acid and 3NP models of HD. Longitudinal monitoring of changes in these metabolites may provide quantifiable measures of disease progression and treatment effects in both mouse models of HD and patients. PMID:17217418

  1. Metabolite Signatures in Hydrophilic Extracts of Mouse Lungs Exposed to Cigarette Smoke Revealed by 1H NMR Metabolomics Investigation

    PubMed Central

    JZ, Hu; X, Wang; J, Feng; BJ, Robertson; KM, Waters; SC, Tilton; JG, Pounds; RA, Corley; M, Liu; M, Hu

    2015-01-01

    1H-NMR metabolomics was used to investigate the changes of metabolites in the lungs of mice with and without being exposed to a controlled amount of cigarette smoke. It was found that the concentrations of adenosine derivatives (i.e. ATP, ADP and AMP), inosine and uridine were significantly changed in the lungs of mice exposed to cigarette smoke when compared with controls regardless the mice were obese or of regular weight. The decreased ATP, ADP, AMP and elevated inosine suggested that the deaminases in charge of adenosine derivatives to inosine derivatives conversion would be significantly changed in the lungs of mice exposed to cigarette smoke. Indeed, transcriptional study confirmed that the concentrations of adenosine monophosphate deaminase 2 and adenosine deaminase 2 were significantly changed in the lungs of mice exposed to cigarette smoke. We also found that the ratio of glycerophosphocholine (GPC) to phosphocholine (PC) was significantly increased in the lungs of obese mice compared with those of the regular weight mice. The GPC/PC ratio was further elevated in the lungs of obese group exposed to cigarette smoke. PMID:26609465

  2. Determination of the enantiomeric purity of the antiasthmatic drug montelukast by means of 1H NMR spectroscopy.

    PubMed

    Redondo, Jordi; Capdevila, Anna; Ciudad, Sonia

    2013-11-01

    In order to define an enantioselective nuclear magnetic resonance (NMR) method for the antiasthmatic drug montelukast, a series of nine easily available products were evaluated as NMR chiral solvating agents (CSAs): D-dibenzoyltartaric acid, D-ditoluoyltartaric acid, (+)-camphorsulfonic acid, (S)-BINOL, (S)-3,3'-diphenyl-2,2'-binaphthyl-1,1'-diol, (R)-3,3''-di-9-anthracenyl-1,1''-bi-2-naphthol, (R)-3,3''-di-9-phenanthrenyl-1,1''-bi-2-naphthol, Pirkle's alcohol, and (-)-cinchonidine. It was proved that most of the studied agents constitute diastereomeric complexes with both drug enantiomers in CD2 Cl2 or CDCl3 solutions, thus permitting the direct (1)H NMR detection of the unwanted S-enantiomer, even at levels of 0.75%. (-)-Cinchonidine was found to be the more convenient CSA in terms of NMR enantiodiscrimination power and ease of experimental requirements. The final method was validated and applied to the fast monitoring of the optical purity of montelukast "in-process" samples, circumventing the need for tedious and slower analytical procedures like enantioselective chromatography or capillary electrophoresis. In addition, a method for the enantiopurity control of the commercial drug (montelukast sodium salt) was also established using (S)-BINOL as NMR CSA. PMID:23893787

  3. 1H-NMR-based profiling of organic components in leachate from animal carcasses disposal site with time.

    PubMed

    Kwon, Yong-Kook; Bae, Hyun-Whee; Shin, Sun Kyoung; Jeon, Tae-Wan; Seo, Jungju; Hwang, Geum-Sook

    2014-09-01

    Leachate, generated by the decomposition of animal carcasses, presents many environmental, sanitary, and food safety hazards. However, research on the characteristics of leachate is lacking. In this study, we performed biochemical profiling of leachate from two animal species (pig and cattle) in two soil types (sandy loam and sandy soil) using (1)H-NMR-based profiling, followed by multivariate data analysis. The leachate was collected from a well-controlled artificial burial site over a 31-week period. Principal components analysis (PCA) of the NMR data showed similar patterns between species and soil types. Organic components, including organic acids and phenols, predominated, and their levels increased with time. The methylamine level in leachate from pig carcasses 18 weeks following burial was significantly higher than that from cattle carcasses; leachate from cattle carcasses in sandy soil 1 week after burial contained unique components (specifically ethanol, formate, alanine, N-methylation, and taurine), in contrast with those from sandy loam soil. This study suggests that a NMR-based profiling approach is useful to characterize the organic components in leachate from animal carcasses over time. PMID:24819439

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

    NASA Astrophysics Data System (ADS)

    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.

  5. [superscript 1]H NMR Spectroscopy-Based Configurational Analysis of Mono- and Disaccharides and Detection of ß-Glucosidase Activity: An Undergraduate Biochemistry Laboratory

    ERIC Educational Resources Information Center

    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…

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

    ERIC Educational Resources Information Center

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

    2012-01-01

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

  7. 1H NMR characterization of the intermediate formed upon UV-A excitation of biopterin, neopterin and 6-hydroxymethylpterin in O 2-free aqueous solutions

    NASA Astrophysics Data System (ADS)

    Vignoni, Mariana; Salum, M. Laura; Erra-Balsells, Rosa; Thomas, Andres H.; Cabrerizo, Franco M.

    2010-01-01

    Pterins belong to a family of heterocyclic compounds present in a wide range of living systems and participate in relevant biological functions. Under anaerobic conditions, the unstable red intermediate generated by UV-A irradiation of biopterin, neopterin and 6-hydroxymethylpterin was identified by 1H NMR analysis, in alkaline D 2O solutions, as 5,8-dihydro-6-formylpterin.

  8. 1H-NMR-Based Metabolic Analysis of Human Serum Reveals Novel Markers of Myocardial Energy Expenditure in Heart Failure Patients

    PubMed Central

    Su, Liang; Lai, Wenyan; Wang, Peng; Xie, Zhibing; Xie, Zhiquan; Zeng, Qingchun; Ren, Hao; Xu, Dingli

    2014-01-01

    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. PMID:24505394

  9. 1H NMR-based metabolomics combined with HPLC-PDA-MS-SPE-NMR for investigation of standardized Ginkgo biloba preparations

    PubMed Central

    Agnolet, Sara; Jaroszewski, Jerzy W.; Verpoorte, Robert

    2010-01-01

    Commercial preparations of Ginkgo biloba are very complex mixtures prepared from raw leaf extracts by a series of extraction and prepurification steps. The pharmacological activity is attributed to a number of flavonoid glycosides and unique terpene trilactones (TTLs), with largely uncharacterized pharmacological profiles on targets involved in neurological disorders. It is therefore important to complement existing targeted analytical methods for analysis of Ginkgo biloba preparations with alternative technology platforms for their comprehensive and global characterization. In this work, 1H NMR-based metabolomics and hyphenation of high-performance liquid chromatography, photo-diode array detection, mass spectrometry, solid-phase extraction, and nuclear magnetic resonance spectroscopy (HPLC-PDA-MS-SPE-NMR) were used for investigation of 16 commercially available preparations of Ginkgo biloba. The standardized extracts originated from Denmark, Italy, Sweden, and United Kingdom, and the results show that 1H NMR spectra allow simultaneous assessment of the content as well as identity of flavonoid glycosides and TTLs based on a very simple sample-preparation procedure consisting of extraction, evaporation and reconstitution in acetone-d6. Unexpected or unwanted extract constituents were also easily identified in the 1H NMR spectra, which contrasts traditional methods that depend on UV absorption or MS ionizability and usually require availability of reference standards. Automated integration of 1H NMR spectral segments (buckets or bins of 0.02 ppm width) provides relative distribution plots of TTLs based on their H-12 resonances. The present study shows that 1H NMR-based metabolomics is an attractive method for non-selective and comprehensive analysis of Ginkgo extracts. Electronic supplementary material The online version of this article (doi:10.1007/s11306-009-0195-x) contains supplementary material, which is available to authorized users. PMID:20526353

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

    NASA Astrophysics Data System (ADS)

    Musio, Roberta; Sciacovelli, Oronzo

    2009-09-01

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

  11. Redox-dependent 1H NMR spectral features and tertiary structural constraints on the C-terminal region of putidaredoxin.

    PubMed

    Pochapsky, T C; Ratnaswamy, G; Patera, A

    1994-05-31

    Putidaredoxin (Pdx) is a 106-residue Fe2S2 ferredoxin which acts as the physiological reductant and effector of cytochrome P-450cam. Pdx has two accessible oxidation states, Fe+3-Fe+3 (oxidized) and Fe+3-Fe+2 (reduced), and exhibits redox-dependent binding affinities for cytochrome P-450cam, with reduced Pdx binding over 100-fold more tightly than oxidized Pdx to the oxidized cytochrome P-450cam [Hintz, M. J., Mock, D. M., Peterson, L. L., Tuttle, K., & Peterson, J. A. (1982) J. Biol. Chem. 257, 14324-14332]. The analysis of two-dimensional 1H NMR experiments has yielded sequential 1H resonance assignments for the diamagnetic regions of the reduced form of Pdx, which are compared to those of oxidized Pdx, described previously [Ye, X. M., Pochapsky, T. C., & Pochapsky, S. S. (1992) Biochemistry 31, 1961-1968]. Increased unpaired electron-spin density on the metal cluster in reduced relative to oxidized Pdx increases the number of 1H resonances which are broadened by the metal cluster, and the pattern of paramagnetic broadening provides information concerning the placement of the metal cluster within the protein. Two-dimensional exchange experiments on half-reduced samples of Pdx indicate that electron self-exchange is slow on the chemical shift time scale, with a second-order rate constant < or = 66 M-1 s-1 at 290 K. Spectral changes unrelated to increases in unpaired electron-spin density are also observed. The largest changes of this type are observed for features structurally contiguous with the C-terminal region Pro 102-Trp 106. The C-terminal residue Trp 106 has been implicated in binding to cytochrome P-450cam.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:8204576

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

    PubMed Central

    2016-01-01

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

  13. Haemolymph from Mytilus galloprovincialis: Response to copper and temperature challenges studied by (1)H-NMR metabonomics.

    PubMed

    Digilio, Giuseppe; Sforzini, Susanna; Cassino, Claudio; Robotti, Elisa; Oliveri, Caterina; Marengo, Emilio; Musso, Davide; Osella, Domenico; Viarengo, Aldo

    2016-01-01

    Numerous studies on molluscs have been carried out to clarify the physiological roles of haemolymph serum proteins and haemocytes. However, little is known about the presence and functional role of the serum metabolites. In this study, Nuclear Magnetic Resonance (NMR) was used to assess whether changes of the metabolic profile of Mytilus galloprovincialis haemolymph may reflect alterations of the physiological status of the organisms due to environmental stressors, namely copper and temperature. Mussel haemolymph was taken from the posterior adductor muscle after a 4-day exposure to ambient (16°C) or high temperature (24°C) and in the absence or presence (5μg/L, 20μg/L, or 40μg/L) of sublethal copper (Cu(2+)). The total glutathione (GSH) concentration in the haemolymph of both control and treated mussels was minimal, indicating the absence of significant contaminations by muscle intracellular metabolites due to the sampling procedure. In the (1)H-NMR spectrum of haemolymph, 27 metabolites were identified unambiguously. The separate and combined effects of exposure to copper and temperature on the haemolymph metabolic profile were assessed by Principal Component Analysis (PCA) and Ranking-PCA multivariate analysis. Changes of the metabolomic profile due to copper exposure at 16°C became detectable at a dose of 20μg/L copper. Alanine, lysine, serine, glutamine, glycogen, glucose and protein aliphatics played a major role in the classification of the metabolic changes according to the level of copper exposition. High temperature (24°C) and high copper levels caused a coherent increase of a common set of metabolites (mostly glucose, serine, and lysine), indicating that the metabolic impairment due to high temperature is enforced by the presence of copper. Overall, the results demonstrate that, as for human blood plasma, the analysis of haemolymph metabolites represents a promising tool for the diagnosis of pollutant-induced stress syndrome in marine mussels

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

    PubMed

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

    2016-05-01

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

  15. Aliphatic chain length by isotropic mixing (ALCHIM): determining composition of complex lipid samples by 1H NMR spectroscopy

    PubMed Central

    Yi, Ruiyang; Volden, Paul A.; Conzen, Suzanne D.

    2015-01-01

    Quantifying the amounts and types of lipids present in mixtures is important in fields as diverse as medicine, food science, and biochemistry. Nuclear magnetic resonance (NMR) spectroscopy can quantify the total amounts of saturated and unsaturated fatty acids in mixtures, but identifying the length of saturated fatty acid or the position of unsaturation by NMR is a daunting challenge. We have developed an NMR technique, aliphatic chain length by isotropic mixing, to address this problem. Using a selective total correlation spectroscopy technique to excite and transfer magnetization from a resolved resonance, we demonstrate that the time dependence of this transfer to another resolved site depends linearly on the number of aliphatic carbons separating the two sites. This technique is applied to complex natural mixtures allowing the identification and quantification of the constituent fatty acids. The method has been applied to whole adipocytes demonstrating that it will be of great use in studies of whole tissues. PMID:24831341

  16. Characterizing Radiation-Aged Polysiloxane-Silica Composites: Identifying Changes in Network Topology via 1H NMR

    SciTech Connect

    Mayer, B; Chinn, S C; Maxwell, R S; Reimer, J

    2008-11-03

    Characterizing and quantifying changes in elastomeric materials upon exposure to harsh environments is important in the estimation of device lifetimes. Nuclear magnetic resonance (NMR) spectroscopy has been used effectively in the analysis of such materials and has proved to be both sensitive to micro- and macroscopic changes associated with material 'aging'. Traditional analyses, however, rely on empirical formulae containing a large number of (often arbitrary) independent variables. This ambiguity can be circumvented largely by developing models of NMR observables that are based on basic polymer physics. We compare two such models, one previously published and one derived herein, along with empirical expressions that describe the proton transverse magnetization decay associated with complex polymer networks. One particular extracted parameter, the proton-proton residual dipolar coupling (RDC), can be directly related to network topology, and a comparison of the extracted RDCs reveals high consistency among the models. An expression derived from the properties of a static Gaussian chain can minimize the number of parameters necessarily to describe the solid-like, networked proton population to a single independent parameter, the average residual dipolar coupling, D{sub avg}.

  17. Correlations between 29Si, 17O and 1H NMR properties and local structures in silicates: an ab initio calculation

    NASA Astrophysics Data System (ADS)

    Xue, X.; Kanzaki, M.

    In order to gain insight into the correlations between 29Si, 17O and 1H NMR properties (chemical shift and quadrupolar coupling parameters) and local structures in silicates, ab initio self-consistent field Hartree-Fock molecular orbital calculations have been carried out on silicate clusters of various polymerizations and intertetrahedral (Si-O-Si) angles. These include Si(OH)4 monomers (isolated as well as interacting), Si2O(OH)6 dimers (C2 symmetry) with the Si-O-Si angle fixed at 5° intervals from 120° to 180°, Si3O2(OH)8 linear trimers (C2 symmetry) with varying Si-O-Si angles, Si3O3(OH)6 three-membered rings (D3 and C1 symmetries), Si4O4(OH)8 four-membered ring (C4 symmetry) and Si8O12(OH)8 octamer (D4 symmetry). The calculated 29Si, 17O and 1H isotropic chemical shifts (δiSi, δiO and δiH) for these clusters are all close to experimental NMR data for similar local structures in crystalline silicates. The calculated 17O quadrupolar coupling constants (QCC) of the bridging oxygens (Si-O-Si) are also in good agreement with experimental data. The calculated 17O QCC of silanols (Si-O-H) are much larger than those of the bridging oxygens, but unfortunately there are no experimental data for similar groups in well-characterized crystalline phases for comparison. There is a good correlation between δiSi and the mean Si-O-Si angle for both Q1 and Q2, where Qn denotes Si with n other tetrahedral Si next-nearest neighbors. Both the δiO and the 17O electric field gradient asymmetry parameter, η of the bridging oxygens have been found to depend strongly on the O site symmetry, in addition to the Si-O-Si angle. On the other hand, the 17O QCC seems to be influenced little by structural parameters other than the Si-O-Si angle, and is thus expected to be the most reliable 17O NMR parameter that can be used to decipher Si-O-Si angle distribution information. Both the 17O QCC and the 2H QCC of silanols decrease with decreasing length of hydrogen bond to a second O atom

  18. Selective Detection of 1H NMR Resonances of 13CH n Groups Using Two-Dimensional Maximum-Quantum Correlation Spectroscopy

    NASA Astrophysics Data System (ADS)

    Liu, M.; Farrant, R. D.; Nicholson, J. K.; Lindon, J. C.

    Methods for editing spectra based upon maximum-quantum filtering in two-dimensional 1H NMR are presented (MAXY NMR). Separation of 1H resonances from 13CH, 13CH 2, and 13CH 3 groups is demonstrated, using the coherence of the attached natural-abundance 13C spin. Two-dimensional correlation pulse sequences based on J connectivity (MAXY-COSY), total J connectivity (MAXY-TOCSY), and NOE and exchange processes (MAXY-NOESY) are given and exemplified using dexamethasone as a model compound. In addition, an improved form of a 13CH 2 only COSY spectrum (gem-COSY) is shown, and the application of z magnetic-field gradients is demonstrated as an alternative to phase cycling. The approach should have utility in the assignment of complex 1H NMR spectra which arise from peptides or complex mixtures such as biofluids.

  19. Correlation between 1H NMR chemical shifts of hydroxyl protons in n-hexanol/cyclohexane and molecular association properties investigated using density functional theory

    NASA Astrophysics Data System (ADS)

    Flores, Mario E.; Shibue, Toshimichi; Sugimura, Natsuhiko; Nishide, Hiroyuki; Moreno-Villoslada, Ignacio

    2016-01-01

    Association of n-hexanol molecules in cyclohexane forming clusters is studied by DFT and 1H NMR. Geometry optimization, corrected binding energies, charge distributions, charge transfer energies, and 1H NMR chemical shifts have been obtained. The calculated chemical shifts of hydroxyl protons have been correlated to experimental data obtained in the range of n-hexanol molar fraction between 0.002 and 0.2, showing that n-hexanol molecules at a molar fraction around 0.1, where well-structured hydrogen bond networks are observed, tend to form linear pentamers and hexamers. The experimental data are consistent with the continuous linear association thermodynamic model, showing a dimensionless association constant of 284.

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

    PubMed Central

    Pegos, Vanessa R.; Canevarolo, Rafael R.; Sampaio, Aline P.; Balan, Andrea; Zeri, Ana C. M.

    2014-01-01

    Xanthomonas is a genus of phytopathogenic bacteria, which produces a slimy, polysaccharide matrix known as xanthan gum, which involves, protects and helps the bacteria during host colonization. Although broadly used as a stabilizer and thickener in the cosmetic and food industries, xanthan gum can be a troubling artifact in molecular investigations due to its rheological properties. In particular, a cross-reaction between reference compounds and the xanthan gum could compromise metabolic quantification by NMR spectroscopy. Aiming at an efficient gum extraction protocol, for a 1H-NMR-based metabolic profiling study of Xanthomonas, we tested four different interventions on the broadly used methanol-chloroform extraction protocol for the intracellular metabolic contents observation. Lower limits for bacterial pellet volumes for extraction were also probed, and a strategy is illustrated with an initial analysis of X. citri’s metabolism by 1H-NMR spectroscopy. PMID:24957023

  1. Analysis of Eisenia fetida earthworm responses to sub-lethal C60 nanoparticle exposure using (1)H-NMR based metabolomics.

    PubMed

    Lankadurai, Brian P; Nagato, Edward G; Simpson, André J; Simpson, Myrna J

    2015-10-01

    The enhanced production and environmental release of Buckminsterfullerene (C60) nanoparticles will likely increase the exposure and risk to soil dwelling organisms. We used (1)H NMR-based metabolomics to investigate the response of Eisenia fetida earthworms to sub-lethal C60 nanoparticle exposure in both contact and soil tests. Principal component analysis of (1)H NMR data showed clear separation between controls and exposed earthworms after just 2 days of exposure, however as exposure time increased the separation decreased in soil but increased in contact tests suggesting potential adaptation during soil exposure. The amino acids leucine, valine, isoleucine and phenylalanine, the nucleoside inosine, and the sugars glucose and maltose emerged as potential bioindicators of exposure to C60 nanoparticles. The significant responses observed in earthworms using NMR-based metabolomics after exposure to very low concentrations of C60 nanoparticles suggests the need for further investigations to better understand and predict their sub-lethal toxicity. PMID:26024814

  2. Metabolomic quality control of commercial Asian ginseng, and cultivated and wild American ginseng using (1)H NMR and multi-step PCA.

    PubMed

    Zhao, Huiying; Xu, Jin; Ghebrezadik, Helen; Hylands, Peter J

    2015-10-10

    Ginseng, mainly Asian ginseng and American ginseng, is the most widely consumed herbal product in the world . However, the existing quality control method is not adequate: adulteration is often seen in the market. In this study, 31 batches of ginseng from Chinese stores were analyzed using (1)H NMR metabolite profiles together with multi-step principal component analysis. The most abundant metabolites, sugars, were excluded from the NMR spectra after the first principal component analysis, in order to reveal differences contributed by less abundant metabolites. For the first time, robust, distinctive and representative differences of Asian ginseng from American ginseng were found and the key metabolites responsible were identified as sucrose, glucose, arginine, choline, and 2-oxoglutarate and malate. Differences between wild and cultivated ginseng were identified as ginsenosides. A substitute cultivated American ginseng was noticed. These results demonstrated that the combination of (1)H NMR and PCA is effective in quality control of ginseng. PMID:26037159

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

    PubMed

    Pegos, Vanessa R; Canevarolo, Rafael R; Sampaio, Aline P; Balan, Andrea; Zeri, Ana C M

    2014-01-01

    Xanthomonas is a genus of phytopathogenic bacteria, which produces a slimy, polysaccharide matrix known as xanthan gum, which involves, protects and helps the bacteria during host colonization. Although broadly used as a stabilizer and thickener in the cosmetic and food industries, xanthan gum can be a troubling artifact in molecular investigations due to its rheological properties. In particular, a cross-reaction between reference compounds and the xanthan gum could compromise metabolic quantification by NMR spectroscopy. Aiming at an efficient gum extraction protocol, for a 1H-NMR-based metabolic profiling study of Xanthomonas, we tested four different interventions on the broadly used methanol-chloroform extraction protocol for the intracellular metabolic contents observation. Lower limits for bacterial pellet volumes for extraction were also probed, and a strategy is illustrated with an initial analysis of X. citri's metabolism by 1H-NMR spectroscopy. PMID:24957023

  4. (1)H NMR metabolomic profiling of the blue crab (Callinectes sapidus) from the Adriatic Sea (SE Italy): A comparison with warty crab (Eriphia verrucosa), and edible crab (Cancer pagurus).

    PubMed

    Zotti, Maurizio; De Pascali, Sandra Angelica; Del Coco, Laura; Migoni, Danilo; Carrozzo, Leonardo; Mancinelli, Giorgio; Fanizzi, Francesco Paolo

    2016-04-01

    The metabolomic profile of blue crab (Callinectes sapidus) captured in the Acquatina lagoon (SE Italy) was compared to an autochthonous (Eriphia verrucosa) and to a commercial crab species (Cancer pagurus). Both lipid and aqueous extracts of raw claw muscle were analyzed by (1)H NMR spectroscopy and MVA (multivariate data analysis). Aqueous extracts were characterized by a higher inter-specific discriminating power compared to lipid fractions. Specifically, higher levels of glutamate, alanine and glycine characterized the aqueous extract of C. sapidus, while homarine, lactate, betaine and taurine characterized E. verrucosa and C. pagurus. On the other hand, only the signals of monounsaturated fatty acids distinguished the lipid profiles of the three crab species. These results support the commercial exploitation and the integration of the blue crab in human diet of European countries as an healthy and valuable seafood. PMID:26593533

  5. Evidence for a conserved binding motif of the dinuclear metal site in mammalian and plant purple acid phosphatases: 1H NMR studies of the di-iron derivative of the Fe(III)Zn(II) enzyme from kidney bean.

    PubMed Central

    Battistuzzi, G; Dietrich, M; Löcke, R; Witzel, H

    1997-01-01

    The di-iron core of mammalian purple acid phosphatases has been reproduced in the plant enzyme from kidney bean (Mr 111000) upon insertion of an Fe(II) ion in place of the native zinc(II) in the dinuclear Fe(III)Zn(II) core. The shortening of the electronic relaxation time of the metal centre allows detection of hyperfine-shifted 1H NMR resonances, although severe broadening due to Curie relaxation prevents independent signal assignment. Nevertheless, comparison of the spectral features of the structurally characterized plant enzyme with those of the mammalian species, which were previously extensively assigned, is consistent with a close similarity of the metal-binding sites, also suggested by previous sequence-alignment studies. Some differences appear to be mainly localized at the M(II) site. Spectral comparison was also carried out on the Fe(III)Co(II) derivatives. PMID:9169589

  6. On the interaction of caffeine with nucleic acids. III. 1H NMR studies of caffeine--5'-adenosine monophosphate and caffeine-poly(riboadenylate) interactions.

    PubMed

    Fritzsche, H; Petri, I; Schütz, H; Weller, K; Sedmera, P; Lang, H

    1980-02-01

    1) The self-association of both caffeine (Cf) and 5'-adenosine monophosphate (AMP) in aqueous solution has been reinvestigated by 1H NMR. The self-association process is characterized by an isodesmic model. The apparent self-association constants of the vertical stacking process are KCf = (10.6 +/- 1.0) M-1 and KAMP = (1.67 +/- 0.17) M-1. The arrangement of the monomeric units in the stacked aggregates is discussed in terms of isoshielding curves theoretically calculated by Giessner-Prettre and Pullman. Models are proposed which are consistent with these and further previous NMR data. 2) The interaction of Cf and AMP has been studied by 1H NMR. The apparent association constant of the complex Cf-AMP is KC-A = (7.3 +/- 1.2) M-1. Two models of the mutual arrangement of AMP and Cf in the complex are proposed on the basis of the calculated isoshielding curves considering both ring current and local atomic diamagnetic anisotropy effects. 3) The interaction of Cf and poly(riboadenylate), (rA)n, is indicated by a downfield shift of the H-8 line but an upfield shifts of the H-2 line in the 1H NMR spectra of (rA)n. The concentration dependence of the 1H NMR shifts of both Cf and (rA)n can be explained by the existence of two binding mechanisms. We suggest (i) partial insertion of Cf between adjacent base residues of ordered single-stranded regions of (rA)n and (ii) outside binding of Cf in form of monomeric Cf as well as of self-associated aggregates. The complex geometry of insertion proposed on the basis of the calculated isoshielding curves is characterized by a stronger overlapping of the Cf ring and the H-2 proton of (rA)n as compared to the H-8 proton. PMID:7357061

  7. Automated structure verification based on a combination of 1D (1)H NMR and 2D (1)H - (13)C HSQC spectra.

    PubMed

    Golotvin, Sergey S; Vodopianov, Eugene; Pol, Rostislav; Lefebvre, Brent A; Williams, Antony J; Rutkowske, Randy D; Spitzer, Timothy D

    2007-10-01

    A method for structure validation based on the simultaneous analysis of a 1D (1)H NMR and 2D (1)H - (13)C single-bond correlation spectrum such as HSQC or HMQC is presented here. When compared with the validation of a structure by a 1D (1)H NMR spectrum alone, the advantage of including a 2D HSQC spectrum in structure validation is that it adds not only the information of (13)C shifts, but also which proton shifts they are directly coupled to, and an indication of which methylene protons are diastereotopic. The lack of corresponding peaks in the 2D spectrum that appear in the 1D (1)H spectrum, also gives a clear picture of which protons are attached to heteroatoms. For all these benefits, combined NMR verification was expected and found by all metrics to be superior to validation by 1D (1)H NMR alone. Using multiple real-life data sets of chemical structures and the corresponding 1D and 2D data, it was possible to unambiguously identify at least 90% of the correct structures. As part of this test, challenging incorrect structures, mostly regioisomers, were also matched with each spectrum set. For these incorrect structures, the false positive rate was observed as low as 6%. PMID:17694570

  8. Evidence for altered metabolic pathways during environmental stress: (1)H-NMR spectroscopy based metabolomics and clinical studies on subjects of sea-voyage and Antarctic-stay.

    PubMed

    Yadav, Anand Prakash; Chaturvedi, Shubhra; Mishra, Kamla Prasad; Pal, Sunil; Ganju, Lilly; Singh, Shashi Bala

    2014-08-01

    The Antarctic context is an analogue of space travel, with close similarity in ambience of extreme climate, isolation, constrained living spaces, disrupted sleep cycles, and environmental stress. The present study examined the impact of the harsh habitat of Antarctica on human physiology and its metabolic pathways, by analyzing human serum samples, using (1)H-NMR spectroscopy for identification of metabolites; and quantifying other physiological and clinical parameters for correlation between expression data and metabolite data. Sera from seven adult males (of median age 36years) who participated in this study, from the 28th Indian Expeditionary group to the Antarctica station Maitri, were collected in chronological sequence. These included: i) baseline control; ii) during ship journey; iii) at Antarctica, in the months of March, May, August and November; to enable study of temporal evolution of monitored physiological states. 29 metabolites in serum were identified from the 400MHz (1)H-NMR spectra. Out of these, 19 metabolites showed significant variations in levels, during the ship journey and the stay at Maitri, compared to the base-line levels. Further biochemical analysis also supported these results, indicating that the ship journey, and the long-term Antarctic exposure, affected kidney and liver functioning. Our metabolite data highlights for the first time the effect of environmental stress on the patho-physiology of the human system. Multivariate analysis tools were employed for this metabonomics study, using (1)H-NMR spectroscopy. PMID:24910139

  9. Inhibitory effect of synthetic aromatic heterocycle thiosemicarbazone derivatives on mushroom tyrosinase: Insights from fluorescence, (1)H NMR titration and molecular docking studies.

    PubMed

    Xie, Juan; Dong, Huanhuan; Yu, Yanying; Cao, Shuwen

    2016-01-01

    Three structurally similar aromatic heterocyclic compounds 2-thiophenecarboxaldehyde (a), 2-furaldehyde (b), 2-pyrrolecarboxaldehyde (c) were chosen and a series of their thiosemicarbazone derivatives(1a-3a, 1b-3b and 1c-3c) were synthesized to evaluate their biological activities as mushroom tyrosinase inhibitors. The inhibitory effects of these compounds on tyrosinase were investigated by using spectrofluorimetry, (1)H NMR titration and molecular docking techniques. From the results of fluorescence spectrum and (1)H NMR titration, it was found that forming complexes between the sulfur atom from thiourea and copper ion of enzyme center may play a key role for inhibition activity. Moreover, investigation of (1)H NMR spectra further revealed that formation of hydrogen bond between inhibitor and enzyme may be helpful to above complexes formation. The results were well coincident with the suggestion of molecular docking and obviously showed that 2-thiophone N(4)-thiosemicarbazone (1a), 2-furfuran N(4)-thiosemicarbazone (1b) and 2-pyrrole N(4)-thiosemicarbazone (1c) are potential inhibitors which deserves further investigation. PMID:26213029

  10. The structure of the aggregate form of bacteriochlorophyll c showing the Q y absorption above 740 nm: a 1H-NMR study

    NASA Astrophysics Data System (ADS)

    Mizoguchi, Tadashi; Matsuura, Katsumi; Shimada, Keizo; Koyama, Yasushi

    1996-09-01

    Bacteriochlorophyll c (3 1S, 8-isobutyl-12-ethyl, farnesyl) was dissolved in a mixture of methylene chloride and carbon tetrachloride (1 : 3), and changes in the 1H-NMR spectrum caused by the titration of methanol were traced. On the basis of the changes in chemical shift due to the ring-current effect of the neighboring macrocycles and in peak intensity (broadening) due to their stacking, the structure of the aggregate form showing the Q y absorption band above 740 nm is proposed: the macrocycles are stacked to form a one-dimensional inclined column, the y axis of each macrocycle being parallel to the long axis of the column.

  11. Revealing Potential Biomarkers of Functional Dyspepsia by Combining 1H NMR Metabonomics Techniques and an Integrative Multi-objective Optimization Method

    PubMed Central

    Wu, Qiaofeng; Zou, Meng; Yang, Mingxiao; Zhou, Siyuan; Yan, Xianzhong; Sun, Bo; Wang, Yong; Chang, Shyang; Tang, Yong; Liang, Fanrong; Yu, Shuguang

    2016-01-01

    Metabonomics methods have gradually become important auxiliary tools for screening disease biomarkers. However, recognition of metabolites or potential biomarkers closely related to either particular clinical symptoms or prognosis has been difficult. The current study aims to identify potential biomarkers of functional dyspepsia (FD) by a new strategy that combined hydrogen nuclear magnetic resonance (1H NMR)-based metabonomics techniques and an integrative multi-objective optimization (LPIMO) method. First, clinical symptoms of FD were evaluated using the Nepean Dyspepsia Index (NDI), and plasma metabolic profiles were measured by 1H NMR. Correlations between the key metabolites and the NDI scores were calculated. Then, LPIMO was developed to identify a multi-biomarker panel by maximizing diagnostic ability and correlation with the NDI score. Finally, a KEGG database search elicited the metabolic pathways in which the potential biomarkers are involved. The results showed that glutamine, alanine, proline, HDL, β-glucose, α-glucose and LDL/VLDL levels were significantly altered in FD patients. Among them, phosphatidycholine (PtdCho) and leucine/isoleucine (Leu/Ile) were positively and negatively correlated with the NDI Symptom Index (NDSI) respectively. Our procedure not only significantly improved the credibility of the biomarkers, but also demonstrated the potential of further explorations and applications to diagnosis and treatment of complex disease. PMID:26743458

  12. 1H NMR-Based Metabolomic Analysis of Sub-Lethal Perfluorooctane Sulfonate Exposure to the Earthworm, Eisenia fetida, in Soil.

    PubMed

    Lankadurai, Brian P; Furdui, Vasile I; Reiner, Eric J; Simpson, André J; Simpson, Myrna J

    2013-01-01

    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. PMID:24958147

  13. Development of a low resolution (1)H NMR spectroscopic technique for the study of matrix mobility in fresh and freeze-thawed hen egg yolk.

    PubMed

    Au, Carmen; Wang, Tong; Acevedo, Nuria C

    2016-08-01

    Three experiments were conducted in developing a low resolution proton nuclear magnetic resonance ((1)H NMR) spectroscopic technique to study matrix mobility in fresh and freeze-thawed gelled yolk. The Carr-Purcell-Meiboom-Gill (CPMG) sequence was used to measure spin-spin relaxation times of proton pools representing major yolk constituents. A component identification test distinguished 3-4 pools. The least mobile pool was assigned to proteins, protein-lipid and protein-water interactions, and the most mobile to unbound water. The remaining pools were assigned to lipids, lipid-protein and lipid-water interactions. A stability test indicated that yolk had varied matrix mobility within the same sample across five days of refrigeration storage. A reproducibility test demonstrated high repeatability of fresh yolk measurements, but significant differences (p<0.05) were found within gelled yolk samples. This research determined that (1)H NMR spectroscopy, a non-destructive technique, can identify yolk components and detect changes in the matrix. PMID:26988489

  14. High resolution 1H NMR-based metabolomics indicates a neurotransmitter cycling deficit in cerebral tissue from a mouse model of Batten disease.

    PubMed

    Pears, Michael R; Cooper, Jonathan D; Mitchison, Hannah M; Mortishire-Smith, Russell J; Pearce, David A; Griffin, Julian L

    2005-12-30

    The neuronal ceroid lipofuscinoses (NCLs) constitute a range of progressive neurological disorders primarily affecting children. Although six of the causative genes have been characterized, the underlying disease pathogenesis for this family of disorders is unknown. Using a metabolomics approach based on high resolution 1H NMR spectroscopy of the cortex, cerebellum, and remaining regions of the brain in conjunction with statistical pattern recognition, we report metabolic deficits associated with juvenile NCL in a Cln3 knock-out mouse model. Tissue from Cln3 null mutant mice aged 1-6 months was characterized by an increased glutamate concentration and a decrease in -amino butyric acid (GABA) concentration in aqueous extracts from the three regions of the brain. These changes are consistent with the reported altered expression of genes involved in glutamate metabolism in older mice and imply a change in neurotransmitter cycling between glutamate/glutamine and the production of GABA. Further variations in myo-inositol, creatine, and N-acetyl-aspartate were also identified. These metabolic changes were distinct from the normal aging/developmental process. Together, these changes represent the first documented pre-symptomatic symptoms of the Cln3 mouse at 1 month of age and demonstrate the versatility of 1H NMR spectroscopy as a tool for phenotyping mouse models of disease. PMID:16239221

  15. A 1H NMR Study of Host/Guest Supramolecular Complexes of a Curcumin Analogue with β-Cyclodextrin and a β-Cyclodextrin-Conjugated Gemini Surfactant.

    PubMed

    Poorghorban, Masoomeh; Karoyo, Abdalla H; Grochulski, Pawel; Verrall, Ronald E; Wilson, Lee D; Badea, Ildiko

    2015-08-01

    Host systems based on β-cyclodextrin (βCD) were employed as pharmaceutical carriers to encapsulate a poorly soluble drug, curcumin analogue (NC 2067), in order to increase its water solubility. βCD was chemically conjugated with an amphiphilic gemini surfactant with the ability to self-assemble and to form nanoscale supramolecular structures. The conjugated molecule, βCDgemini surfactant (βCDg), was shown to be a promising drug delivery agent. In this report, its physicochemical properties were assessed in aqueous solution using 1D and 2D 1H NMR spectroscopy. The results showed that the apolar hydrocarbon domain of the gemini surfactant was self-included within the βCD internal cavity. The host/guest complexes composed of native βCD or βCDg with NC 2067 were examined using 1D/2D ROESY NMR methods. The stoichiometry of βCD/NC 2067 complex was estimated using Job's method via 1H NMR spectroscopy. The binding geometry of NC 2067 within βCD was proposed using molecular docking and further supported by 1D and 2D ROESY NMR results. Addition of NC 2067 to βCDg revealed minimal changes to the overall structure of the βCDg system, in agreement with the formation of a βCDg/NC 2067 ternary complex. PMID:26083126

  16. Prediction of variability in CYP3A4 induction using a combined 1H NMR metabonomics and targeted UPLC-MS approach.

    PubMed

    Rahmioglu, Nilufer; Le Gall, Gwénaëlle; Heaton, James; Kay, Kristine L; Smith, Norman W; Colquhoun, Ian J; Ahmadi, Kourosh R; Kemsley, E Kate

    2011-06-01

    The activity of Cytochrome P450 3A4 (CYP3A4) enzyme is associated with many adverse or poor therapeutic responses to drugs. We used (1)H NMR-based metabonomics to identify a metabolic signature associated with variation in induced CYP3A4 activity. A total of 301 female twins, aged 45--84, participated in this study. Each volunteer was administered a potent inducer of CYP3A4 (St. John's Wort) for 14 days and the activity of CYP3A4 was quantified through the metabolism of the exogenously administered probe drug quinine sulfate (300 mg). Pre- and postintervention fasting urine samples were used to obtain metabolite profiles, using (1)H NMR spectroscopy, and were analyzed using UPLC--MS to obtain a marker for CYP3A4 induction, via the ratio of 3-hydroxyquinine to quinine (3OH-Q:Q). Multiple linear regression was used to build a predictive model for 3OH-Q:Q values based on the preintervention metabolite profiles. A combination of seven metabolites and seven covariates showed a strong (r = 0.62) relationship with log(3OH-Q:Q). This regression model demonstrated significant (p < 0.00001) predictive ability when applied to an independent validation set. Our results highlight the promise of metabonomics for predicting CYP3A4-mediated drug response. PMID:21491888

  17. Metabonomic Profiling of Serum and Urine by 1H NMR-Based Spectroscopy Discriminates Patients with Chronic Obstructive Pulmonary Disease and Healthy Individuals

    PubMed Central

    Liu, Shuo; Mao, Shitao; Ling, Yuan; Liu, Dan; He, Xiaoyu; Wang, Xiaoge

    2013-01-01

    Chronic obstructive pulmonary disease (COPD) has seriously impacted the health of individuals and populations. In this study, proton nuclear magnetic resonance (1H NMR)-based metabonomics combined with multivariate pattern recognition analysis was applied to investigate the metabolic signatures of patients with COPD. Serum and urine samples were collected from COPD patients (n = 32) and healthy controls (n = 21), respectively. Samples were analyzed by high resolution 1H NMR (600 MHz), and the obtained spectral profiles were then subjected to multivariate data analysis. Consistent metabolic differences have been found in serum as well as in urine samples from COPD patients and healthy controls. Compared to healthy controls, COPD patients displayed decreased lipoprotein and amino acids, including branched-chain amino acids (BCAAs), and increased glycerolphosphocholine in serum. Moreover, metabolic differences in urine were more significant than in serum. Decreased urinary 1-methylnicotinamide, creatinine and lactate have been discovered in COPD patients in comparison with healthy controls. Conversely, acetate, ketone bodies, carnosine, m-hydroxyphenylacetate, phenylacetyglycine, pyruvate and α-ketoglutarate exhibited enhanced expression levels in COPD patients relative to healthy subjects. Our results illustrate the potential application of NMR-based metabonomics in early diagnosis and understanding the mechanisms of COPD. PMID:23755267

  18. (1)H NMR and GC-MS Based Metabolomics Reveal Defense and Detoxification Mechanism of Cucumber Plant under Nano-Cu Stress.

    PubMed

    Zhao, Lijuan; Huang, Yuxiong; Hu, Jerry; Zhou, Hongjun; Adeleye, Adeyemi S; Keller, Arturo A

    2016-02-16

    Because copper nanoparticles are being increasingly used in agriculture as pesticides, it is important to assess their potential implications for agriculture. Concerns have been raised about the bioaccumulation of nano-Cu and their toxicity to crop plants. Here, the response of cucumber plants in hydroponic culture at early development stages to two concentrations of nano-Cu (10 and 20 mg/L) was evaluated by proton nuclear magnetic resonance spectroscopy ((1)H NMR) and gas chromatography-mass spectrometry (GC-MS) based metabolomics. Changes in mineral nutrient metabolism induced by nano-Cu were determined by inductively coupled plasma-mass spectrometry (ICP-MS). Results showed that nano-Cu at both concentrations interferes with the uptake of a number of micro- and macro-nutrients, such as Na, P, S, Mo, Zn, and Fe. Metabolomics data revealed that nano-Cu at both levels triggered significant metabolic changes in cucumber leaves and root exudates. The root exudate metabolic changes revealed an active defense mechanism against nano-Cu stress: up-regulation of amino acids to sequester/exclude Cu/nano-Cu; down-regulation of citric acid to reduce the mobilization of Cu ions; ascorbic acid up-regulation to combat reactive oxygen species; and up-regulation of phenolic compounds to improve antioxidant system. Thus, we demonstrate that nontargeted (1)H NMR and GC-MS based metabolomics can successfully identify physiological responses induced by nanoparticles. Root exudates metabolomics revealed important detoxification mechanisms. PMID:26751164

  19. Comparative molecular field analysis and comparative molecular similarity index analysis studies on 1H NMR chemical shift of NH group of diaryl triazene derivatives.

    PubMed

    Rofouie, M K; Salahinejad, M; Ghasemi, J B; Aghaei, A

    2013-05-01

    Comparative molecular field analysis (CoMFA), comparative molecular field analysis region focusing (CoMFA-RF) for optimizing the region for the final partial least square analysis, and comparative molecular similarity indices analysis (CoMSIA) methods were employed to develop three-dimensional quantitative structure-activity relationship (3D-QSAR) models of (1)H NMR chemical shift of NH proton of diaryl triazene derivatives. The best orientation was searched by all-orientation search (AOS) strategy to minimize the effect of the initial orientation of the structures. The predictive abilities of CoMFA-RF and CoMSIA models were determined using a test set of ten compounds affording predictive correlation coefficients of 0.721 and 0.754, respectively, indicating good predictive power. For further model validation, cross validation (leave one out), progressive scrambling, and bootstrapping were also applied. The accuracy and speed of obtained 3D-QSAR models for the prediction of (1)H NMR chemical shifts of NH group of diaryl triazene derivatives were greater compared to some computational well-known procedures. PMID:23456682

  20. (1)H NMR-Based Metabolomics and Neurotoxicity Study of Cerebrum and Cerebellum in Rats Treated with Cinnabar, a Traditional Chinese Medicine.

    PubMed

    Wei, Lai; Xue, Rong; Zhang, Panpan; Wu, Yijie; Li, Xiaojing; Pei, Fengkui

    2015-08-01

    Cinnabar, an important traditional Chinese mineral medicine, has been widely used as a Chinese patent medicine ingredient for sedative therapy. Nevertheless, the neurotoxic effects of cinnabar have also been noted. In this study, (1)H NMR-based metabolomics, combined with multivariate pattern recognition, were applied to investigate the neurotoxic effects of cinnabar after intragastrical administration (dosed at 2 and 5 g/kg body weight) on male Wistar rats. The metabolite variations induced by cinnabar were characterized by increased levels of glutamate, glutamine, myo-inositol, and choline, as well as decreased levels of GABA, taurine, NAA, and NAAG in tissue extracts of the cerebellum and cerebrum. These findings suggested that cinnabar induced glutamate excitotoxicity, neuronal cell loss, osmotic state changes, membrane fluidity disruption, and oxidative injury in the brain. We also show here that there is a dose- and time-dependent neurotoxicity of cinnabar, and that cerebellum was more sensitive to cinnabar induction than cerebrum. This work illustrates the utility and reliability of (1)H NMR-based metabolomics approach for examining the potential neurotoxic effects of cinnabar and other traditional Chinese medicines. PMID:26110755

  1. Solution structure of Fe(II) cytochrome c551 from Pseudomonas aeruginosa as determined by two-dimensional sup 1 H NMR

    SciTech Connect

    Detlefsen, D.J.; Thanabal, V.; Wagner, G. ); Pecoraro, V.L. )

    1991-09-17

    The solution structure of Fe(II) cytochrome c551 from Pseudomonas aeruginosa based on 2D{sup 1}H NMR data is reported. Two sets of structure calculations were completed with a combination of simulated annealing and distance geometry calculations: one set of 20 structures included the heme-peptide covalent linkages, and one set of 10 structures excluded them. The main-chain atoms were well constrained within the two structural ensembles (1.30 and 1.35 {angstrom} average RMSD, respectively) except for two regions spanning residues 30-40 and 60-70. The results were essentially the same when global fold comparisons were made between the ensembles with an average RMSD of 1.33 {angstrom}. In total, 556 contraints were used, including 479 NOEs, 53 volume constraints, and 24 other distances. This report represents the first solution structure determination of a heme protein by 2D {sup 1}H NMR and should provide a basis for the application of these techniques to other proteins containing large prosthetic groups or cofactors.

  2. 1H NMR-Based Metabolomic Analysis of Sub-Lethal Perfluorooctane Sulfonate Exposure to the Earthworm, Eisenia fetida, in Soil

    PubMed Central

    Lankadurai, Brian P.; Furdui, Vasile I.; Reiner, Eric J.; Simpson, André J.; Simpson, Myrna J.

    2013-01-01

    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. PMID:24958147

  3. Direct and real-time quantification of tenofovir release from pH-sensitive microparticles into simulated biological fluids using 1H-NMR

    PubMed Central

    Oyler, Nathan A.; Youan, Bi-Botti C.

    2014-01-01

    In vitro drug release evaluation is a very important step toward the quality control of nano- or micro-particular drug delivery systems. However, most quantitative techniques such as HPLC requires a dialysis membrane to separate the released free drug from these delivery systems, thus are not capable of direct detection and real-time quantification of the drug release. This study describes for the first time, a rapid, specific, and direct method for the real-time quantification of in vitro tenofovir (TNF) release from pH-sensitive microparticles using a Varian 400 MHZ 1H nuclear magnetic resonance (1H-NMR) spectrometer. Various analytical performance parameters such as linearity, precision, accuracy, limit of quantification (LOQ), limit of detection (LOD), and robustness were validated according to International Conference on Harmonization (ICH) guidelines. The in vitro release of TNF from microparticles in both simulated vaginal fluid (VFS) and the mixture (VSFS) of VFS and simulated semen fluid (SFS) was monitored and quantified in real-time using 1H-NMR. The capability of real-time quantification of in vitro drug release from microparticles not only provides a more accurate prediction of its biological behavior in vivo, but is also independent of potential interference from the dialysis membrane. PMID:24765652

  4. Quantum decoherence and quasi-equilibrium in open quantum systems with few degrees of freedom: Application to 1H NMR of nematic liquid crystals

    NASA Astrophysics Data System (ADS)

    Segnorile, Héctor H.; Zamar, Ricardo C.

    2011-12-01

    Explanation of decoherence and quasi-equilibrium in systems with few degrees of freedom demands a deep theoretical analysis that considers the observed system as an open quantum system. In this work, we study the problem of decoherence of an observed system of quantum interacting particles, coupled to a quantum lattice. Our strategy is based on treating the environment and the system-environment Hamiltonians fully quantum mechanically, which yields a representation of the time evolution operator useful for disentangling the different time scales underlying in the observed system dynamics. To describe the possible different stages of the dynamics of the observed system, we introduce quantum mechanical definitions of essentially isolated, essentially adiabatic, and thermal-contact system-environment interactions. This general approach is then applied to the study of decoherence and quasi-equilibrium in proton nuclear magnetic resonance (1H NMR) of nematic liquid crystals. A summary of the original results of this work is as follows. We calculate the decoherence function and apply it to describe the evolution of a coherent spin state, induced by the coupling with the molecular environment, in absence of spin-lattice relaxation. By assuming quantum energy conserving or non-demolition interactions, we identify an intermediate time scale, between those controlled by self-interactions and thermalization, where coherence decays irreversibly. This treatment is also adequate for explaining the buildup of quasi-equilibrium of the proton spin system, via the process we called eigen-selectivity. By analyzing a hypothetical time reversal experiment, we identify two sources of coherence loss which are of a very different nature and give rise to distinct time scales of the spin dynamics: (a) reversible or adiabatic quantum decoherence and (b) irreversible or essentially adiabatic quantum decoherence. Local irreversibility arises as a consequence of the uncertainty introduced by

  5. Quantum decoherence and quasi-equilibrium in open quantum systems with few degrees of freedom: application to 1H NMR of nematic liquid crystals.

    PubMed

    Segnorile, Héctor H; Zamar, Ricardo C

    2011-12-28

    Explanation of decoherence and quasi-equilibrium in systems with few degrees of freedom demands a deep theoretical analysis that considers the observed system as an open quantum system. In this work, we study the problem of decoherence of an observed system of quantum interacting particles, coupled to a quantum lattice. Our strategy is based on treating the environment and the system-environment Hamiltonians fully quantum mechanically, which yields a representation of the time evolution operator useful for disentangling the different time scales underlying in the observed system dynamics. To describe the possible different stages of the dynamics of the observed system, we introduce quantum mechanical definitions of essentially isolated, essentially adiabatic, and thermal-contact system-environment interactions. This general approach is then applied to the study of decoherence and quasi-equilibrium in proton nuclear magnetic resonance ((1)H NMR) of nematic liquid crystals. A summary of the original results of this work is as follows. We calculate the decoherence function and apply it to describe the evolution of a coherent spin state, induced by the coupling with the molecular environment, in absence of spin-lattice relaxation. By assuming quantum energy conserving or non-demolition interactions, we identify an intermediate time scale, between those controlled by self-interactions and thermalization, where coherence decays irreversibly. This treatment is also adequate for explaining the buildup of quasi-equilibrium of the proton spin system, via the process we called eigen-selectivity. By analyzing a hypothetical time reversal experiment, we identify two sources of coherence loss which are of a very different nature and give rise to distinct time scales of the spin dynamics: (a) reversible or adiabatic quantum decoherence and (b) irreversible or essentially adiabatic quantum decoherence. Local irreversibility arises as a consequence of the uncertainty introduced by

  6. (1)H NMR-based metabolite profiling workflow to reduce inter-sample chemical shift variations in urine samples for improved biomarker discovery.

    PubMed

    Gil, Ryan B; Lehmann, Rainer; Schmitt-Kopplin, Philippe; Heinzmann, Silke S

    2016-07-01

    peaks with standard phosphate buffering and with in silico alignment. C citrate peak with additional potassium fluoride and standard phosphate buffering without in silico alignment. D citrate peaks with additional potassium fluoride and standard phosphate buffering with in silico alignment. Below the respective spectrum are displayed the percent relative standard deviation (RSD) of the respective citrate peaks. This is a measure of the positional noise of peaks within a (1)H NMR analysis. It can be seen that D performs the best in reducing positional noise of citrate peaks. E-H STOCSY analysis of correlating spectral features with the driver peak at 2.675 ppm (see red arrow) to identify structural correlations. As a, b, c, and d are known to be structurally correlated, STOCSY analysis should reveal r (2) = 1 if data is perfectly aligned and can therefore be used as a measure of peak alignment. E Strong positional noise does not allow identifying the c and d peaks of the AB system to be correlated. F, G Neither in silico alignment or KF addition alone can completely improve the alignment and therefore increase the correlations. H Highly improved alignment by combining both KF addition and in silico alignment reduces positional noise and elucidates all four citrate peaks to be strongly correlated. PMID:27178551

  7. Properties of aromatic residues in ferricytochrome c3 of desulforvibrio vulgaris Miyazaki F studied by 1H NMR

    NASA Astrophysics Data System (ADS)

    Park, Jang-Su; Enoki, Minoru; Ohbu, Ayako; Fan, Kejung; Niki, Katsumi; Akutsu, Hideo; Kyogoku, Yoshimasa

    1991-01-01

    Conditions for the specific labelling of the tetrahaeme protein cytochrome c3 of Desulfovibrio vulgaris Miyazaki F during culture of this sulphate-reducing bacterium in a minimal medium were established. Phenylalanine and tyrosine residues were specifically deuterated at more than 85% efficiency. Cytochrome c3 has nine histidine, three tyrosine and two phenylalamine residues. Eight histidine imidazoles are ligated to four haeme groups. Using the deuterated cytochrome c3, aromatic proton signals of phenylalanine and tyrosine residues in the fully oxidized state were identified. However, the signals of one phenylalanine residue were missing and this was tentatively assigned to Phe20. The aromatic proton signals of His67 were also assigned p2H titration. Its pk1 was much higher than that for the free histidine residue. No tyrosine residue was ionized up to p2H 12.

  8. (1)H NMR spectroscopic elucidation in solution of the kinetics and thermodynamics of spin crossover for an exceptionally robust Fe(2+) complex.

    PubMed

    Petzold, Holm; Djomgoue, Paul; Hörner, Gerald; Speck, J Matthäus; Rüffer, Tobias; Schaarschmidt, Dieter

    2016-09-21

    A series of Fe(2+) spin crossover (SCO) complexes [Fe(5/6)](2+) employing hexadentate ligands (5/6) with cis/trans-1,2-diamino cyclohexanes (4) as central building blocks were synthesised. The ligands were obtained by reductive amination of 4 with 2,2'-bipyridyl-6-carbaldehyde or 1,10-phenanthroline-2-carbaldehyde 3. The chelating effect and the rigid structure of the ligands 5/6 lead to exceptionally robust Fe(2+) and Zn(2+) complexes conserving their structure even in coordinating solvents like dmso at high temperatures. Their solution behavior was investigated using variable temperature (VT) (1)H NMR spectroscopy and VT Vis spectroscopy. SCO behavior was found for all Fe(2+) complexes in this series centred around and far above room temperature. For the first time we have demonstrated that the thermodynamics as well as kinetics for SCO can be deduced by using VT (1)H NMR spectroscopy. An alternative scheme using a linear correction term C(1) to model chemical shifts for Fe(2+) SCO complexes is presented. The rate constant for the SCO of [Fe(rac-trans-5)](2+) obtained by VT (1)H NMR was validated by Laser Flash Photolysis (LFP), with excellent agreement (1/(kHL + kLH) = 33.7/35.8 ns for NMR/LFP). The solvent dependence of the transition temperature T1/2 and the solvatochromism of complex [Fe(rac-trans-5)](2+) were ascribed to hydrogen bond formation of the secondary amine to the solvent. Enantiomerically pure complexes can be prepared starting with R,R- or S,S-1,2-diaminocyclohexane (R,R-trans-4 or S,S-trans-4). The high robustness of the complexes reduces a possible ligand scrambling and allows preparation of quasiracemic crystals of [Zn(R,R-5)][Fe(S,S-5)](ClO4)4·(CH3CN) composed of a 1 : 1 mixture of the Zn and Fe complexes with inverse chirality. PMID:27506162

  9. Predicting paramagnetic 1H NMR chemical shifts and state-energy separations in spin-crossover host-guest systems.

    PubMed

    Isley, William C; Zarra, Salvatore; Carlson, Rebecca K; Bilbeisi, Rana A; Ronson, Tanya K; Nitschke, Jonathan R; Gagliardi, Laura; Cramer, Christopher J

    2014-06-14

    The behaviour of metal-organic cages upon guest encapsulation can be difficult to elucidate in solution. Paramagnetic metal centres introduce additional dispersion of signals that is useful for characterisation of host-guest complexes in solution using nuclear magnetic resonance (NMR). However, paramagnetic centres also complicate spectral assignment due to line broadening, signal integration error, and large changes in chemical shifts, which can be difficult to assign even for known compounds. Quantum chemical predictions can provide information that greatly facilitates the assignment of NMR signals and identification of species present. Here we explore how the prediction of paramagnetic NMR spectra may be used to gain insight into the spin crossover (SCO) properties of iron(II)-based metal organic coordination cages, specifically examining how the structure of the local metal coordination environment affects SCO. To represent the tetrahedral metal-organic cage, a model system is generated by considering an isolated metal-ion vertex: fac-ML3(2+) (M = Fe(II), Co(II); L = N-phenyl-2-pyridinaldimine). The sensitivity of the (1)H paramagnetic chemical shifts to local coordination environments is assessed and utilised to shed light on spin crossover behaviour in iron complexes. Our data indicate that expansion of the metal coordination sphere must precede any thermal SCO. An attempt to correlate experimental enthalpies of SCO with static properties of bound guests shows that no simple relationship exists, and that effects are likely due to nuanced dynamic response to encapsulation. PMID:24752730

  10. Hydrogen bonds and a hydrogen-bonded chain in mannich bases of 5,5'-dinitro-2,2'-biphenol-FT-IR and 1H NMR studies

    NASA Astrophysics Data System (ADS)

    Brzezinski, Bogumil; Urjasz, Hanna; Bartl, Franz; Zundel, Georg

    1997-11-01

    5,5'-Dinitro-3-diethylaminomethyl-2,2'-biphenol ( 1) and 5,5'-dinitro-3,3' bis(diethylaminomethyl)-2,2'-biphenol ( 2) as well as 5,5'-dinitro-2,2'-biphenol ( 3) were synthesized and studied by FT-IR and 1H NMR spectroscopy in acetonitrile or acetonitrile-d 3 solutions, respectively. With compound 1 a hydrogen-bonded system with large proton polarizability is found. In the hydrogen bonds in compound 2 the protons are localized at the N atoms. These hydrogen bonds show no proton polarizability. In the protonated compound 2 a very strong homoconjugated -O⋯H +⋯O - hydrogen bond with large proton polarizability is found, whereas two other protons are localized at the N atoms. The deviation of the results obtained with other derivatives of 2,2'-biphenols are caused by the larger acidity of the nitro groups.

  11. Study of the gel films of Acetobacter Xylinum cellulose and its modified samples by {sup 1}H NMR cryoporometry and small-angle X-ray scattering

    SciTech Connect

    Babushkina, T. A.; Klimova, T. P.; Shtykova, E. V.; Dembo, K. A.; Volkov, V. V.; Khripunov, A. K.; Klechkovskaya, V. V.

    2010-03-15

    Gel films of Acetobacter Xylinum cellulose and its modified samples have been investigated by 1H nuclear magnetic resonance (NMR) cryoporometry and small-angle X-ray scattering. The joint use of these two methods made it possible to characterize the sizes of aqueous pores in gel films and estimate the sizes of structural inhomogeneities before and after the sorption of polyvinylpyrrolidone and Se{sub 0} nanoparticles (stabilized by polyvinylpyrrolidone) into the films. According to small-angle X-ray scattering data, the sizes of inhomogeneities in a gel film change only slightly upon the sorption of polyvinylpyrrolidone and nanoparticles. The impregnated material is sorbed into water-filled cavities that are present in the gel film. {sup 1}H NMR cryoporometry allowed us to reveal the details of changes in the sizes of small aqueous pores during modifications.

  12. Isotope-detected 1H NMR studies of proteins: a general strategy for editing interproton nuclear Overhauser effects by heteronuclear decoupling, with application to phage lambda repressor.

    PubMed Central

    Weiss, M A; Redfield, A G; Griffey, R H

    1986-01-01

    A strategy for editing interproton nuclear Overhauser effects (NOEs) in proteins is proposed and illustrated. Selective incorporation of 13C- (or 15N)-labeled amino acids into a protein permits NOEs involving the labeled residues to be identified by heteronuclear difference decoupling. Such heteronuclear editing simplifies the NOE difference spectrum and avoids ambiguities due to spin diffusion. Isotope-detected 1H NMR thus opens to study proteins too large for conventional one- and two-dimensional NMR methods (20-75 kDa). We have applied this strategy to the N-terminal domain of phage lambda repressor, a protein of dimer molecular mass 23 kDa. A tertiary NOE from an internal aromatic ring (Phe-51) to a beta-13C-labeled alanine residue (Ala-62) is demonstrated. PMID:3006046

  13. Study of the gel films of Acetobacter Xylinum cellulose and its modified samples by 1H NMR cryoporometry and small-angle X-ray scattering

    NASA Astrophysics Data System (ADS)

    Babushkina, T. A.; Klimova, T. P.; Shtykova, É. V.; Dembo, K. A.; Volkov, V. V.; Khripunov, A. K.; Klechkovskaya, V. V.

    2010-03-01

    Gel films of Acetobacter Xylinum cellulose and its modified samples have been investigated by 1H nuclear magnetic resonance (NMR) cryoporometry and small-angle X-ray scattering. The joint use of these two methods made it possible to characterize the sizes of aqueous pores in gel films and estimate the sizes of structural inhomogeneities before and after the sorption of polyvinylpyrrolidone and Se0 nanoparticles (stabilized by polyvinylpyrrolidone) into the films. According to small-angle X-ray scattering data, the sizes of inhomogeneities in a gel film change only slightly upon the sorption of polyvinylpyrrolidone and nanoparticles. The impregnated material is sorbed into water-filled cavities that are present in the gel film. 1H NMR cryoporometry allowed us to reveal the details of changes in the sizes of small aqueous pores during modifications.

  14. Quantum mechanical and spectroscopic (FT-IR, FT-Raman, 1H NMR and UV) investigations of 5-nitro-2-phenylbenzoxazole

    NASA Astrophysics Data System (ADS)

    Bhagyasree, J. B.; Varghese, Hema Tresa; Panicker, C. Yohannan; Samuel, Jadu; Van Alsenoy, Christian; Ertan-Bolelli, Tugba; Yildiz, Ilkay

    2014-04-01

    The optimized molecular structure, vibrational wavenumbers, corresponding vibrational assignments of 5-nitro-2-phenylbenzoxazole have been investigated experimentally and theoretically. The energy and oscillator strength calculated by Time Dependent Density Functional Theory results almost compliments with experimental findings. Gauge-including atomic orbital 1H-NMR chemical shifts calculations were carried out and compared with experimental data. The HOMO and LUMO analysis is used to determine the charge transfer with in the molecule. The stability of the molecule arising from hyper-conjugative interaction and charge delocalization has been analyzed using NBO analysis. molecular electrostatic potential was performed by the DFT method and the infrared intensities and Raman activities are also been reported. Fist hyperpolarizability is calculated in order to find its role in nonlinear optics. Antimicrobial properties indicated that the title compound possessed a broad spectrum activity against the tested Gram-positive, Gram-negative bacteria.

  15. Design, synthesis and 1H NMR study of C3v-symmetric anion receptors with urethane-NH as recognition group

    NASA Astrophysics Data System (ADS)

    Park, Jin-Oh; Sahoo, Suban K.; Choi, Heung-Jin

    2016-01-01

    C3v-Symmetric anion receptors 3 and 4 with urethane groups were synthesized by using trindane triol as tripodal molecular framework. In 1H NMR titration study, the receptors showed noticeable downfield shift/disappearance of the urethane-NH peak in presence of H2PO4- and F- due to the host-guest complexation occurred through multiple hydrogen bonding and/or the deprotonation of urethane-NH groups. Other tested anions such as Cl-, Br-, HSO4-, and NO3- showed either no or negligible chemical shift of the urethane groups. The deprotonation event in 4 allowed selective detection of F- by perceptible color change from colorless to yellowish-red with the appearance of a new charge transfer absorption band at 450 nm.

  16. Electronic, infrared, mass, 1H NMR spectral studies of the charge-transfer complexes of sulphonamide drugs with π-acceptors in acetonitrile

    NASA Astrophysics Data System (ADS)

    Frag, Eman Y.; Mohamed, Gehad G.

    2010-08-01

    The rapid interaction between sulphonamides (sulphamethoxazole (SMZ), sulphaguanidine (SGD), sulphaquinoxaline sodium (SQX) and sulphadimidine sodium (SDD)) as n-electron donors with the 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) and 2,5-dichloro-3,6-dihydroxy-1,4-benzoquinone (chloranilic acid, p-CLA) as π-acceptors resulted in the formation of 1:1 charge-transfer complexes as the final products with the formula [(drug) (acceptor)]. The final products of the reactions have been isolated and characterized using FT-IR, 1H NMR, mass spectroscopy and elemental analyses as well as photometric measurements and thermogravimetric analysis (TG). The stoichiometry and apparent formation constants of the complexes formed were determined by applying the conventional spectrophotometric molar ratio method.

  17. (1)H NMR-based metabolomics study on a goldfish model of Parkinson's disease induced by 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP).

    PubMed

    Lu, Zhaoguang; Wang, Junsong; Li, Minghui; Liu, Qingwang; Wei, Dandan; Yang, Minghua; Kong, Lingyi

    2014-11-01

    A goldfish (Carassius auratus) model of Parkinson's disease (PD) was constructed by a single dose of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) according to previously reported methods. Global metabolite changes in brain of the MPTP induced goldfish model of PD were investigated. (1)H NMR-based metabolomics combined with various statistical methods such as orthogonal partial least squares discriminant analysis (OPLS-DA) and two-dimensional statistical total correlation spectroscopy (2D-STOCSY) found significant increase of leucine, isoleucine, valine, alanine, alanylalanine, creatinine, myo-inositol, 18:2 fatty acid, total fatty acids, arachic alcohol, taurine and significant decrease of N-acetylaspartate, (phospho)creatine, (phospho)choline, betaine, glutamine, 3-hexenedioate, acetamide, malonate, isocitrate, scyllo-inositol, phosphatidylcholines, cholesterols, n-3 fatty acids, polyunsaturated fatty acids (PUFAs) in brain of MPTP induced PD goldfish. These disturbed metabolite levels were involved in oxidative stress, energy failure, neuronal cell injury and death, consistent with those observed in clinical PD patients, and rodents and primates model of PD, indicating that the acute MPTP model of goldfish was an ideal and valuable model for PD research. In addition, several unusual metabolites in brain were significantly changed between MPTP induced PD and control goldfish, which might also play an important role in the pathogenesis of PD. This study also demonstrated the applicability and potential of (1)H NMR-based metabolomics approach for evaluation of animal models of disease induced by chemicals, such as MPTP-induced PD goldfish. PMID:25242684

  18. Identification of serine and histidine adducts in complexes of trypsin and trypsinogen with peptide and nonpeptide boronic acid inhibitors by 1H NMR spectroscopy.

    PubMed

    Tsilikounas, E; Kettner, C A; Bachovchin, W W

    1992-12-29

    We have previously shown, in 15N NMR studies of the enzyme's active site histidine residue, that boronic acid inhibitors can form two distinct types of complexes with alpha-lytic protease. Inhibitors that are structural analogs of good alpha-lytic protease substrates form transition-state-like tetrahedral complexes with the active site serine whereas those that are not form complexes in which N epsilon 2 of the active site histidine is covalently bonded to the boron of the inhibitor. This study also demonstrated that the serine and histidine adduct complexes exhibit quite distinctive and characteristic low-field 1H NMR spectra [Bachovchin, W. W., Wong, W. Y. L., Farr-Jones, S., Shenvi, A. B., & Kettner, C. A. (1988) Biochemistry 27, 7689-7697]. Here we have used low-field 1H NMR diagnostically for a series of boronic acid inhibitor complexes of trypsin and trypsinogen. The results show that H-D-Val-Leu-boroArg and Ac-Gly-boroArg, analogs of good trypsin substrates, form transition-state-like serine adducts with trypsin, whereas the nonsubstrate analog inhibitors boric acid, methane boronic acid, butane boronic acid, and triethanolamine borate all form histidine adducts, thereby paralleling the previous results obtained with alpha-lytic protease. However, with trypsinogen, Ac-Gly-boroArg forms predominantly a histidine adduct while H-D-Val-Leu-boroArg forms both histidine and serine adducts, with the histidine adduct predominating below pH 8.0 and the serine adduct predominating above pH 8.0.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:1463754

  19. Hydrogen Bonding, (1)H NMR, and Molecular Electron Density Topographical Characteristics of Ionic Liquids Based on Amino Acid Cations and Their Ester Derivatives.

    PubMed

    Rao, Soniya S; Bejoy, Namitha Brijit; Gejji, Shridhar P

    2015-08-13

    Amino acid ionic liquids (AAILs) have attracted significant attention in the recent literature owing to their ubiquitous applications in diversifying areas of modern chemistry, materials science, and biosciences. The present work focuses on unraveling the molecular interactions underlying AAILs. Electronic structures of ion pairs consisting of amino acid cations ([AA(+)], AA = Gly, Ala, Val, Leu, Ile, Pro, Ser, Thr) and their ester substituted derivatives [AAE(+)] interacting with nitrate anion [NO3(-)] have been obtained from the dispersion corrected M06-2x density functional theory. The formation of ion pair is accompanied by the transfer of proton from quaternary nitrogen to anion facilitated via hydrogen bonding. The [Ile], [Pro], [Ser], and [Thr] and their esters reveal relatively strong inter- as well as intramolecular hydrogen-bonding interactions. Consequently, the hierarchy in binding energies of [AA][NO3] ion pairs and their ester analogues turns out to be [Gly] > [Ala] > [Ser] ∼ [Val] ∼ [Ile] > [Leu] ∼ [Thr] > [Pro]. The work underlines how the interplay of intra- as well as intermolecular hydrogen-bonding interactions in [AA]- and [AAE]-based ILs manifest in their infrared and (1)H NMR spectra. Substitution of -OCH3 functional group in [AA][NO3] ILs lowers the melting point attributed to weaker hydrogen-bonding interactions, making them suitable for room temperature applications. As opposed to gas phase structures, the presence of solvent (DMSO) does not bring about any proton transfer in the ion pairs or their ester analogues. Calculated (1)H NMR chemical shifts of the solvated structures agree well with those from experiment. Correlations of decomposition temperatures in [AA]- and [AAE]-based ILs with binding energies and electron densities at the bond critical point(s) in molecular electron density topography, have been established. PMID:26192454

  20. Determination of the effect of different additives in coking blends using a combination of in situ high-temperature {sup 1}H NMR and rheometry

    SciTech Connect

    Miguel C. Diaz; Karen M. Steel; Trevor C. Drage; John W. Patrick; Colin E. Snape

    2005-12-01

    High-temperature {sup 1}H NMR and rheometry measurements were carried out on 4:1 wt/wt blends of a medium volatile bituminous coal with two anthracites, two petroleum cokes, charcoal, wood, a low-temperature coke breeze, tyre crumb, and active carbon to determine the effects on fluidity development to identify the parameters responsible for these effects during pyrolysis and to study possible relationships among the parameters derived from these techniques. Positive, negative, and neutral effects were identified on the concentration of fluid material. Small positive effects (ca. 5-6%) were caused by blending the coal with petroleum cokes. Charcoal, wood, and active carbon all exerted negative effects on concentration (18-27% reduction) and mobility (12-25% reduction in T2) of the fluid phase, which have been associated with the inert character and high surface areas of these additives that adsorb the fluid phase of the coal. One of the anthracites and the low-temperature coke breeze caused deleterious effects to a lesser extent on the concentration (7-12%) and mobility (13-17%) of the fluid material, possibly due to the high concentration of metals in these additives (ca. 11% ash). Despite the high fluid character of tyre crumb at the temperature of maximum fluidity of the coal (73%), the mobility of the fluid phase of the blend was lower than expected. The comparison of {sup 1}H NMR and rheometry results indicated that to account for the variations in minimum complex viscosity for all the blends, both the maximum concentration of fluid phase and the maximum mobility of the fluid material had to be considered. For individual blends, two exponential relationships have been found between the complex viscosity and the concentration of solid phase in both the softening and resolidification stages but the parameters are different for each blend. 30 refs., 8 figs., 5 tabs.

  1. Systemic and characteristic metabolites in the serum of streptozotocin-induced diabetic rats at different stages as revealed by a (1)H-NMR based metabonomic approach.

    PubMed

    Diao, Chengfeng; Zhao, Liangcai; Guan, Mimi; Zheng, Yongquan; Chen, Minjiang; Yang, Yunjun; Lin, Li; Chen, Weijian; Gao, Hongchang

    2014-03-01

    Diabetes mellitus is a typical heterogeneous metabolic disorder characterized by abnormal metabolism of carbohydrates, lipids, and proteins. Investigating the changes in metabolic pathways during the evolution of diabetes mellitus may contribute to the understanding of its metabolic features and pathogenesis. In this study, serum samples were collected from diabetic rats and age-matched controls at different time points: 1 and 9 weeks after streptozotocin (STZ) treatment. (1)H nuclear magnetic resonance ((1)H NMR)-based metabonomics with quantitative analysis was performed to study the metabolic changes. The serum samples were also subjected to clinical chemistry analysis to verify the metabolic changes observed by metabonomics. Partial least squares discriminant analysis (PLS-DA) demonstrated that the levels of serum metabolites in diabetic rats are different from those in control rats. These findings indicate that the metabolic characteristics of the two groups are markedly different at 1 and 9 weeks. Quantitative analysis showed that the levels of some metabolites, such as pyruvate, lactate, citrate, acetone, acetoacetate, acetate, glycerol, and valine, varied in a time-dependent manner in diabetic rats. These results suggest that serum metabolites related to glycolysis, the tricarboxylic acid cycle, gluconeogenesis, fatty acid β-oxidation, branched-chain amino acid metabolism, and the tyrosine metabolic pathways are involved in the evolution of diabetes. The metabolic changes represent potential features and promote a better understanding of the mechanisms involved in the development of diabetes mellitus. This work further suggests that (1)H NMR metabonomics is a valuable approach for providing novel insights into the pathogenesis of diabetes mellitus and its complications. PMID:24448714

  2. Two- and three-dimensional sup 1 H NMR studies of a wheat phospholipid transfer protein: Sequential resonance assignments and secondary structure

    SciTech Connect

    Simorre, J.P.; Caille, A. ); Marion, D. ); Marion, D. ); Ptak, M. Univ. d'Orleans )

    1991-12-10

    Two- and three-dimensional {sup 1}H NMR experiments have been used to sequentially assign nearly all proton resonances of the 90 residues of wheat phospholipid transfer protein. Only a few side-chain protons were not identified because of degeneracy or overlapping. The identification of spin systems and the sequential assignment were made at the same time by combining the data of the two- and three-dimensional experiments. The classical two-dimensional COSY, HOHAHA, and NOESY experiments benefit from both good resolution and high sensitivity, allowing the detection of long-range dipolar connectivities. The three-dimensional HOHAHA-NOESY experiment offers the advantage of a faster and unambiguous assignment. As a matter of fact, homonuclear three-dimensional NMR spectroscopy prove to be a very efficient method for resonance assignments of protein {sup 1}H NMR spectra which cannot be unraveled by 2D methods. An assignment strategy which overcomes most of the ambiguities has been proposed, in which each individual assignment toward the C-terminal end is supported by another in the opposite direction originating from a completely different part of the spectrum. Location of secondary structures of the phospholipid transfer protein was determined by using the method of analysis introduced here and was confirmed by {sup 3}J{sub {alpha}NH} coupling and NH exchange rates. Except for the C-terminal part, the polypeptide chain appears to be organized mainly as helical fragments connected by disulfide bridges. Further modeling will display the overall folding of the protein and should provide a better understanding of its interactions with lipids.

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

    NASA Astrophysics Data System (ADS)

    Schröder, Leif; Bachert, Peter

    2003-10-01

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

  4. New findings on the in vivo antioxidant activity of Curcuma longa extract by an integrated (1)H NMR and HPLC-MS metabolomic approach.

    PubMed

    Dall'Acqua, Stefano; Stocchero, Matteo; Boschiero, Irene; Schiavon, Mariano; Golob, Samuel; Uddin, Jalal; Voinovich, Dario; Mammi, Stefano; Schievano, Elisabetta

    2016-03-01

    Curcuminoids possess powerful antioxidant activity as demonstrated in many chemical in vitro tests and in several in vivo trials. Nevertheless, the mechanism of this activity is not completely elucidated and studies on the in vivo antioxidant effects are still needed. Metabolomics may be used as an attractive approach for such studies and in this paper, we describe the effects of oral administration of a Curcuma longa L. extract (150mg/kg of total curcuminoids) to 12 healthy rats with particular attention to urinary markers of oxidative stress. The experiment was carried out over 33days and changes in the 24-h urine samples metabolome were evaluated by (1)H NMR and HPLC-MS. Both techniques produced similar representations for the collected samples confirming our previous study. Modifications of the urinary metabolome lead to the observation of different variables proving the complementarity of (1)H NMR and HPLC-MS for metabolomic purposes. The urinary levels of allantoin, m-tyrosine, 8-hydroxy-2'-deoxyguanosine, and nitrotyrosine were decreased in the treated group thus supporting an in vivo antioxidant effect of the oral administration of Curcuma extract to healthy rats. On the other hand, urinary TMAO levels were higher in the treated compared to the control group suggesting a role of curcumin supplementation on microbiota or on TMAO urinary excretion. Furthermore, the urinary levels of the sulphur containing compounds taurine and cystine were also changed suggesting a role for such constituents in the biochemical pathways involved in Curcuma extract bioactivity and indicating the need for further investigation on the complex role of antioxidant curcumin effects. PMID:26712080

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

    PubMed

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

    2015-09-01

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

  6. Evidence for tautomerism in nucleic acid base pairs. 1H NMR study of 15N labeled tRNA.

    PubMed Central

    Rüterjans, H; Kaun, E; Hull, W E; Limbach, H H

    1982-01-01

    The imino proton resonances of 15N labeled tRNA appear as asymmetric doublet signals, the asymmetry being dependent on the applied magnetic field strength. Assuming a tautomerism of the type N-H...N not equal to N...H-N in the base pairs the line shapes can be simulated. The most important parameters fitted in the simulation are the rate constants of the proton transfer and the mole fractions of either tautomeric state. The rate constants are of the order of 100s-1 and the mole fractions of the non dominant tautomer about 0.1 depending on the temperature and on the nature of the base pairing. The observations are attributed to a double proton transfer in the base pairs. The unexpectedly slow rates of the double proton transfer process may be connected with a concomitant conformational change of the duplex structure. PMID:7177856

  7. Influence of the colloidal structure of dairy gels on milk fat fusion behavior: quantification of the liquid fat content by in situ quantitative proton nuclear magnetic resonance spectroscopy (isq (1) H NMR).

    PubMed

    Bouteille, Romain; Perez, Jeanne; Khifer, Farid; Jouan-Rimbaud-Bouveresse, Delphine; Lecanu, Bruno; This, Hervé

    2013-04-01

    Dairy gels (DG), such as yoghurts, contain both solid and liquid fats at the time of consumption, as their temperature rises to anything between 10 and 24 °C after being introduced into the mouth at 4 °C. The mass ratio between solid and liquid fats, which depends on the temperature, impacts the organoleptic properties of DG. As the ordinary methods for determining this ratio can only be applied to samples consisting mainly in fat materials, a fat extraction step needs to be added into the analytical process when applied to DG, which prevents the study of the potential impact of their colloidal structure on milk fat fusion behavior. In situ quantitative proton nuclear magnetic resonance spectroscopy (isq (1) H NMR) was investigated as a method for direct measurements in DG: at temperatures between 20.0 and 70.0 °C, the liquid fat content and the composition of triacylglycerols of the liquid phase (in terms of alkyl chains length) were determined. Spectra of isolated milk fat also enable the quantification of the double bonds of triacylglycerols. Statistical tests showed no significant difference between isolated milk fat and milk fat inside a DG in terms of melting behavior: the fat globule membrane does not seem to have a significant influence on the fat melting behavior. PMID:23464867

  8. (1)H-NMR analysis of the human urinary metabolome in response to an 18-month multi-component exercise program and calcium-vitamin-D3 supplementation in older men.

    PubMed

    Sheedy, John R; Gooley, Paul R; Nahid, Amsha; Tull, Dedreia L; McConville, Malcolm J; Kukuljan, Sonja; Nowson, Caryl A; Daly, Robin M; Ebeling, Peter R

    2014-11-01

    The musculoskeletal benefits of calcium and vitamin-D3 supplementation and exercise have been extensively studied, but the effect on metabolism remains contentious. Urine samples were analyzed by (1)H-NMR spectroscopy from participants recruited for an 18-month, randomized controlled trial of a multi-component exercise program and calcium and vitamin-D3 fortified milk consumption. It was shown previously that no increase in musculoskeletal composition was observed for participants assigned to the calcium and vitamin-D3 intervention, but exercise resulted in increased bone mineral density, total lean body mass, and muscle strength. Retrospective metabolomics analysis of urine samples from patients involved in this study revealed no distinct changes in the urinary metabolome in response to the calcium and vitamin-D3 intervention, but significant changes followed the exercise intervention, notably a reduction in creatinine and an increase in choline, guanidinoacetate, and hypoxanthine (p < 0.001, fold change > 1.5). These metabolites are intrinsically involved in anaerobic ATP synthesis, intracellular buffering, and methyl-balance regulation. The exercise intervention had a marked effect on the urine metabolome and markers of muscle turnover but none of these metabolites were obvious markers of bone turnover. Measurement of specific urinary exercise biomarkers may provide a basis for monitoring performance and metabolic response to exercise regimes. PMID:25198310

  9. (1)H NMR based metabolomics approach to study the toxic effects of dichlorvos on goldfish (Carassius auratus).

    PubMed

    Liu, Yan; Chen, Ting; Li, Ming-Hui; Xu, Hua-Dong; Jia, Ai-Qun; Zhang, Jian-Fa; Wang, Jun-Song

    2015-11-01

    Dichlorvos (DDVP), one of the most widely used organophosphorus pesticides (OPs), has caused serious pollution in environment. In this study, (1)H nuclear magnetic resonance (NMR) based metabolomics approach combined with histopathological and immunohistochemical examination, and biochemical assays were used to investigate toxicities of DDVP on goldfish (Carassius auratus). After 10 days' exposure of DDVP at three dosages of 5.18, 2.59 and 1.73 mg/L, goldfish tissues (gill, brain, liver and kidney) and serum were collected. Histopathology revealed severe impairment of gills, livers and kidneys, and immunohistochemistry disclosed glial fibrillary acidic protein (GFAP) positive reactive astrocytes in brains. Orthogonal signal correction-partial least squares-discriminant analysis (OSC-PLS-DA) of NMR profiles disclosed that DDVP influenced many metabolites (glutamate, aspartate, acetylcholine, 4-aminobutyrate, glutathione, AMP and lactate in brain; glutathione, glucose, histamine in liver; BCAAs, AMP, aspartate, glutamate, riboflavin in kidney) dose-dependently, involved with imbalance of neurotransmitters, oxidative stress, and disorders of energy and amino acid metabolism. Several self-protection mechanisms concerning glutamate degradation and glutathione (GSH) redox system were found in DDVP intoxicated goldfish. PMID:26210017

  10. Chemical Origins of Permanent Set in a Peroxide Cured Filled Silicone Elastomer - Tensile and 1H NMR Analysis

    SciTech Connect

    Chinn, S; Deteresa, S; Shields, A; Sawvel, A; Balazs, B; Maxwell, R S

    2004-10-29

    The aging of a commercial filled siloxane polymeric composite in states of high stress and Co-60 {gamma}-radiation exposure has been studied. DC-745 is a commercially available silicone elastomer consisting of dimethyl, methyl-phenyl, and vinyl-methyl siloxane monomers crosslinked with a peroxide vinyl specific curing agent. It is filled with {approx}30 wt.% mixture of high and low surface area silicas. This filled material is shown to be subject to permanent set if exposed to radiation while under tensile stress. Tensile modulus measurements show that the material gets marginally softer with combined radiation exposure and tensile strain as compared to material exposed to radiation without tensile strain. In addition, the segmental dynamics as measured by both uniaxial NMR relaxometry and Multiple Quantum NMR methods indicate that the material is undergoes radiatively-induced crosslinking in the absence of tensile strain and a combination of crosslinking and strain dependent increase in dynamic order parameter for the network chains. The MQ-NMR also suggests a small change in the number of polymer chains associated with the silica filler surface. Comparison of the prediction of the relative change in crosslink density from the NMR data as well as solvent swelling data and from that predicted from the Tobolsky model suggest that degradation leads to a deviation from Gaussian chain statistics and the formation of increased numbers of elastically ineffective network chains.

  11. Change of translational-rotational coupling in liquids revealed by field-cycling {sup 1}H NMR

    SciTech Connect

    Meier, R.; Schneider, E.; Rössler, E. A.

    2015-01-21

    Applying the field-cycling nuclear magnetic resonance technique, the frequency dependence of the {sup 1}H spin-lattice relaxation rate, R{sub 1}(ω)=T{sub 1}{sup −1}(ω), is measured for propylene glycol (PG) which is increasingly diluted with deuterated chloroform. A frequency range of 10 kHz–20 MHz and a broad temperature interval from 220 to about 100 K are covered. The results are compared to those of experiments, where glycerol and o-terphenyl are diluted with their deuterated counter-part. Reflecting intra- as well as intermolecular relaxation, the dispersion curves R{sub 1}(ω,x) (x denotes mole fraction PG) allow to extract the rotational time constant τ{sub rot}(T, x) and the self-diffusion coefficient D(T, x) in a single experiment. The Stokes-Einstein-Debye (SED) relation is tested in terms of the quantity D(T, x) τ{sub rot}(T, x) which provides a measure of an effective hydrodynamic radius or equivalently of the spectral separation of the translational and the rotational relaxation contribution. In contrast to o-terphenyl, glycerol and PG show a spectral separation much larger than suggested by the SED relation. In the case of PG/chloroform mixtures, not only an acceleration of the PG dynamics is observed with increasing dilution but also the spectral separation of rotational and translational relaxation contributions continuously decreases. Finally, following a behavior similar to that of o-terphenyl already at about x = 0.6; i.e., while D(T, x) τ{sub rot}(T, x) in the mixture is essentially temperature independent, it strongly increases with x signaling thus a change of translational-rotational coupling. This directly reflects the dissolution of the hydrogen-bond network and thus a change of solution structure.

  12. Monitoring changes in the structure and properties of humic substances following ozonation using UV-Vis, FTIR and (1)H NMR techniques.

    PubMed

    Rodríguez, Francisco J; Schlenger, Patrick; García-Valverde, María

    2016-01-15

    The main objective of this work is to conduct a comprehensive structural characterization of humic substances using the following experimental techniques: FTIR, 1H NMR and several UV–Vis parameters (Specific UV Absorbance at 254 nm or SUVA254, SUVA280, A400, the absorbance ratios A210/254, A250/365, A254/203, A254/436, A265/465, A270/400, A280/350, A465/665, the Absorbance Slope Index (ASI), the spectral slopes S275–295, S350–400 and the slope ratio SR). These UV–Vis parameters have also been correlated with key properties of humic substances such as aromaticity, molecular weight (MW) and trihalomethane formation potential (THMFP). An additional objective of this work is also to evaluate the usefulness of these techniques to monitor structural changes in humic substances produced by the ozonation treatment. Four humic substances were studied in this work: three of them were provided by the International Humic Substances Society (Suwannee River Fulvic Acid Standard: SRFA, Suwannee River Humic Acid Standard: SRHA and Nordic Reservoir Fulvic Acid Reference: NLFA) and the other one was a terrestrial humic acid widely used as a surrogate for aquatic humic substances in various studies (Aldrich Humic Acid: AHA). The UV–Vis parameters showing the best correlations with aromaticity in this study were SUVA254, SUVA280, A280/A350 ratio and A250/A364 ratio. The best correlations with molecular weight were for SUVA254, SUVA280 and A280/A350 ratio. Finally, in the case of the THMFP it was STHMFP-per mol HS the parameter showing good correlations with most of the UV–Vis parameters studied (especially with A280/A350 ratio, A265/A465 ratio and A270/A400 ratio) whereas STHMFP-per mg C showed poor correlations in most cases. On the whole, the UV–Vis parameter showing the best results was A280/A350 ratio as it showed excellent correlations for the three properties studied (aromaticity, MW and THMFP). A decrease in aromaticity following ozonation of humic substances can

  13. Sequence specific molecular recognition by a monocationic lexitropsin of the decadeoxyribonucleotide d-[CATGGCCATG]2: structural and dynamic aspects deduced from high field 1H-NMR studies.

    PubMed Central

    Lee, M; Hartley, J A; Pon, R T; Krowicki, K; Lown, J W

    1988-01-01

    All 1H-NMR resonances of d-[CATGGCCATG]2 and the 1:1 complex of lexitropsin 1 and the DNA were assigned by the NOE difference, COSY and NOESY methods. Addition of 1 causes the base and imino protons for the sequence 5'-CCAT to undergo the most marked drug-induced chemical shift changes, thereby indicating that 1 is located in this base pair sequence. NOEs confirmed the location and orientation of the drug in the 1:1 complex, with the amino terminus oriented to C(6). The van der Waals interaction between H12a,b of 1 and AH2(8) may be responsible for reading of the 3' A.T base pair in the 5'-CCAT sequence. Exchange NMR effects allow an estimate of approximately equal to 62 s-1 for the intramolecular "slide-swing" exchange of the lexitropsin between two equivalent binding sites with delta G = 58 +/- 5 kJ mol-1 at 301 degrees K. PMID:2829134

  14. Dereplication of antioxidant compounds in Bene (Pistacia atlantica subsp. mutica) hull using a multiplex approach of HPLC-DAD, LC-MS and (1)H NMR techniques.

    PubMed

    Rezaie, Mitra; Farhoosh, Reza; Pham, Ngoc; Quinn, Ronald J; Iranshahi, Mehrdad

    2016-01-01

    Bene is an edible fruit from the tree Pistacia atlantica subsp. mutica, and is of steadily growing interest in recent years due to its significant antioxidant properties and potential health benefits. An antioxidant activity-guided fractionation of the methanol extract from Bene hull together with an integrated approach of HPLC-DAD, LC-MS and (1)H NMR techniques led to the identification of main antioxidant phenolic compounds for the first time. Radical scavenging activity of each fraction/compound was tested using DPPH and FRAP assays. The phenolic content of the fractions was also determined by Folin-Ciocalteu's method. The main identified antioxidant compounds were luteolin (46.53% w/w of total extract), gallic acid (9.84% w/w), 2″-O-galloylisoquercitrin (0.53% w/w), quercetin 3-rutinoside (0.34% w/w) and 2″-O-cis-caffeoylquercitrin (0.26% w/w). The minor antioxidant compounds were also identified by liquid chromatography-positive/negative electrospray ionization tandem mass spectrometry. The structure-antioxidant activity relationship of identified phenolics are also discussed in this paper. PMID:26432386

  15. An Investigation into the Antiobesity Effects of Morinda citrifolia L. Leaf Extract in High Fat Diet Induced Obese Rats Using a 1H NMR Metabolomics Approach

    PubMed Central

    Gooda Sahib Jambocus, Najla; Saari, Nazamid; Ismail, Amin; Mahomoodally, Mohamad Fawzi; Abdul Hamid, Azizah

    2016-01-01

    The prevalence of obesity is increasing worldwide, with high fat diet (HFD) as one of the main contributing factors. Obesity increases the predisposition to other diseases such as diabetes through various metabolic pathways. Limited availability of antiobesity drugs and the popularity of complementary medicine have encouraged research in finding phytochemical strategies to this multifaceted disease. HFD induced obese Sprague-Dawley rats were treated with an extract of Morinda citrifolia L. leaves (MLE 60). After 9 weeks of treatment, positive effects were observed on adiposity, fecal fat content, plasma lipids, and insulin and leptin levels. The inducement of obesity and treatment with MLE 60 on metabolic alterations were then further elucidated using a 1H NMR based metabolomics approach. Discriminating metabolites involved were products of various metabolic pathways, including glucose metabolism and TCA cycle (lactate, 2-oxoglutarate, citrate, succinate, pyruvate, and acetate), amino acid metabolism (alanine, 2-hydroxybutyrate), choline metabolism (betaine), creatinine metabolism (creatinine), and gut microbiome metabolism (hippurate, phenylacetylglycine, dimethylamine, and trigonelline). Treatment with MLE 60 resulted in significant improvement in the metabolic perturbations caused obesity as demonstrated by the proximity of the treated group to the normal group in the OPLS-DA score plot and the change in trajectory movement of the diseased group towards the healthy group upon treatment. PMID:26798649

  16. sup 1 H NMR studies of plastocyanin from Scenedesmus obliquus: Complete sequence-specific assignment, secondary structure analysis, and global fold

    SciTech Connect

    Moore, J.M.; Chazin, W.J.; Wright, P.E. ); Powls, R. )

    1988-10-04

    Two-dimensional {sup 1}H NMR methods have been used to make sequence-specific resonance assignments for the 97 amino acid residues of the plastocyanin from the green alga Scenedesmus obliquus. Assignments were obtained for all backbone protons and the majority of the side-chain protons. Spin system identification relied heavily on the observation of relayed connectivities to the backbone amide proton. Sequence-specific assignments were made by using the sequential assignment procedure. During this process, an extra valine residue was identified that had not been detected in the original amino acid sequence. Elements of regular secondary structure were identified from characteristic NOE connectivities between backbone protons, coupling constant values, and the observation of slowly exchanging amide protons. The protein in solution contains eight {beta}-strands, one short segment of helix, five reverse turns, and five loops. The {beta}-strands may be arranged into two {beta}sheets on the basis of extensive cross-strand NOE connectivities. The chain-folding topology determined from the NMR experiments is that of a Greek key {beta}-barrel and is similar to that observed for French bean plastocyanin in solution and poplar plastocyanin in the crystalline state. While the overall structures are similar, several differences in local structure between the S. obliquus and higher plant plastocyanins have been identified.

  17. 1H NMR Based Serum Metabolic Profiles Associated with Pathological Progression of Pancreatic Islet β Cell Tumor in Rip1-Tag2 Mice

    PubMed Central

    Yang, Yongxia; Liu, Ying; Zheng, Lingyun; Zhang, Qianqian; Gu, Quliang; Wang, Linlin; Wang, Lijing

    2015-01-01

    Pancreatic islet β cell tumor is the most common islet cell tumor. A well-characterized tumor progression in Rip1-Tag2 mice undergoes five stages, involving normal, hyperplasia, angiogenic islets, tumorigenesis and invasive carcinoma. 1H NMR based metabonomics was applied to identify potential biomarkers for monitoring pancreatic islet β cell tumor progression in Rip1-Tag2 mice. Multivariate analysis results showed the serum metabonome at hyperplasia stage shared the similar characteristics with the ones at normal stage as a result of slight proliferation of pancreatic islet β cells. At angiogenic islets stage, the up-regulated glycolysis, disturbed choline and phospholipid metabolism composed the metabolic signature. In addition to the changes mentioned above, several metabolites were identified as early biomarkers for tumorigenesis, including increased methionine, citrate and choline, and reduced acetate, taurine and glucose, which suggested the activated energy and amino acid metabolism. All the changes were aggravated at invasive carcinoma stage, coupled with notable changes in alanine, glutamate and glycine. Moreover, the distinct metabolic phenotype was found associated with the implanting of SV40 large T antigen in Rip1-Tag2 mice. The combined metabolic and multivariate statistics approach provides a robust method for screening the biomarkers of disease progression and examining the association between gene and metabolism. PMID:25892966

  18. 1H NMR sequential assignments and secondary structure analysis of human fibrinogen gamma-chain C-terminal residues 385-411

    SciTech Connect

    Mayo, K.H.; Burke, C.; Lindon, J.N.; Kloczewiak, M. )

    1990-04-03

    The human fibrinogen gamma-chain, C-terminal fragment, residues 385-411, i.e., KIIPFNRLTIGEGQQHHLGGAKQAGDV, contains two biologically important functional domains: (1) fibrinogen gamma-chain polymerization center and (2) platelet receptor recognition domain. This peptide was isolated from cyanogen bromide degraded human fibrinogen and was investigated by 1H NMR (500 MHz) spectroscopy. Sequence-specific assignments of NMR resonances were obtained for backbone and side-chain protons via analysis of 2D NMR COSY, double quantum filtered COSY, HOHAHA, and NOESY spectra. The N-terminal segment from residues 385-403 seems to adopt a relatively fixed solution conformation. Strong sequential alpha CH-NH NOESY connectivities and a continuous run of NH-NH NOESY connectivities and several long-lived backbone NH protons strongly suggest the presence of multiple-turn or helix-like structure for residues 390 to about 402. The conformation of residues 403-411 seems to be much less constrained as evidenced by the presence of weaker and sequential alpha CH-NH NOEs, the absence of sequential NH-NH NOEs, and the lack of longer lived amides. Chemical shifts of resonances from backbone and side-chain protons of the C-terminal dodecapeptide, residues 400-411, differ significantly from those of the parent chain, suggesting that some preferred C-terminal conformation does exist.

  19. Modified syntheses of dopamine-4-sulfate, epinephrine-3-sulfate, and norepinephrine-3-sulfate: determination of the position of the sulfate group by 1H-NMR spectroscopy.

    PubMed

    Lernhardt, U; Strobel, G; Schell, H; Werle, E; Weicker, H

    1988-08-01

    With respect to the growing interest in sulfoconjugated catecholamines (CAS), reliable syntheses of those substances including high purification and unequivocal identification are required. For the syntheses of the 3-O-sulfates of norepinephrine (NE) and epinephrine (EPI), modifications of the methods of Stolz (12) and Arakawa et al. (1) were performed. Noradrenalone and adrenalone were prepared according to the method of Stolz (12) and sulfated by reaction with pyridine-sulfurtrioxide complex in dry pyridine at 60 degrees C. After reduction of these ketosulfates by sodium borohydride in dry pyridine, NE-3-O-S and EPI-3-O-S were obtained respectively. We synthesized dopamine-4-O-sulfate (DA-4-O-S) by reaction of DA hydrochloride with pyridine-sulfurtrioxide complex in dry dimethylformamide at 20 degrees C (Harbeson et al., 1983). The highly purified products (DA-4-O-S, NE-3-O-S, EPI-3-O-S) were characterized by their melting points (mp), infrared spectra (IR), thin-layer chromatography (TLC), high-performance liquid chromatography (HPLC), elemental analysis, and 1H-nuclear magnetic resonance spectroscopy (1H-NMR). PMID:3182167

  20. An Investigation into the Antiobesity Effects of Morinda citrifolia L. Leaf Extract in High Fat Diet Induced Obese Rats Using a (1)H NMR Metabolomics Approach.

    PubMed

    Gooda Sahib Jambocus, Najla; Saari, Nazamid; Ismail, Amin; Khatib, Alfi; Mahomoodally, Mohamad Fawzi; Abdul Hamid, Azizah

    2016-01-01

    The prevalence of obesity is increasing worldwide, with high fat diet (HFD) as one of the main contributing factors. Obesity increases the predisposition to other diseases such as diabetes through various metabolic pathways. Limited availability of antiobesity drugs and the popularity of complementary medicine have encouraged research in finding phytochemical strategies to this multifaceted disease. HFD induced obese Sprague-Dawley rats were treated with an extract of Morinda citrifolia L. leaves (MLE 60). After 9 weeks of treatment, positive effects were observed on adiposity, fecal fat content, plasma lipids, and insulin and leptin levels. The inducement of obesity and treatment with MLE 60 on metabolic alterations were then further elucidated using a (1)H NMR based metabolomics approach. Discriminating metabolites involved were products of various metabolic pathways, including glucose metabolism and TCA cycle (lactate, 2-oxoglutarate, citrate, succinate, pyruvate, and acetate), amino acid metabolism (alanine, 2-hydroxybutyrate), choline metabolism (betaine), creatinine metabolism (creatinine), and gut microbiome metabolism (hippurate, phenylacetylglycine, dimethylamine, and trigonelline). Treatment with MLE 60 resulted in significant improvement in the metabolic perturbations caused obesity as demonstrated by the proximity of the treated group to the normal group in the OPLS-DA score plot and the change in trajectory movement of the diseased group towards the healthy group upon treatment. PMID:26798649

  1. Comparative 1H NMR Metabolomic Urinalysis of People Diagnosed with Balkan Endemic Nephropathy, and Healthy Subjects, in Romania and Bulgaria: A Pilot Study

    PubMed Central

    Mantle, Peter; Modalca, Mirela; Nicholls, Andrew; Tatu, Calin; Tatu, Diana; Toncheva, Draga

    2011-01-01

    1H NMR spectroscopy of urine has been applied to exploring metabolomic differences between people diagnosed with Balkan endemic nephropathy (BEN), and treated by haemodialysis, and those without overt renal disease in Romania and Bulgaria. Convenience sampling was made from patients receiving haemodialysis in hospital and healthy controls in their village. Principal component analysis clustered healthy controls from both countries together. Bulgarian BEN patients clustered separately from controls, though in the same space. However, Romanian BEN patients not only also clustered away from controls but also clustered separately from the BEN patients in Bulgaria. Notably, the urinary metabolomic data of two people sampled as Romanian controls clustered within the Romanian BEN group. One of these had been suspected of incipient symptoms of BEN at the time of selection as a ‘healthy’ control. This implies, at first sight, that metabolomic analysis can be predictive of impending morbidity before conventional criteria can diagnose BEN. Separate clustering of BEN patients from Romania and Bulgaria could indicate difference in aetiology of this particular silent renal atrophy in different geographic foci across the Balkans. PMID:22069742

  2. X-ray and 1H-NMR spectroscopic studies of the structures and conformations of the new nootropic agents RU-35929, RU-47010 and RU-35965

    NASA Astrophysics Data System (ADS)

    Amato, Maria E.; Bandoli, Giuliano; Casellato, Umberto; Pappalardo, Giuseppe C.; Toja, Emilio

    1990-10-01

    The crystal and molecular structures of the nootropics (±)1-benzenesulphonyl-2-oxo-5-ethoxypyrrolidine ( 1), (±)1-(3-pyridinylsulphonyl)-2-oxo-5-ethoxypyrrolidine ( 2) and (±)1-benzenesulphonyl-2-oxo-5-isopropyloxypyrrolidine ( 3) have been determined by X-ray analysis. The solution conformation of 1, 2 and 3 has been investigated by 1H NMR spectroscopy. In the solid state, the main feature consists of the similar structural parameters and conformations, with the exception of the conformation adopted by the 5-ethoxy moiety which changes on passing from 1 to 2. The solid state overall enveloped conformation of the 2-pyrrolidinone ring for the three nootropics is found to be retained in solution on the basis of NMR evidence. Comparison between calculated and experimental coupling constant values shows that one of the two possible puckered opposite conformational isomers (half-chair shapes) occurs in solution. The relative pharmacological potencies of 1, 2 and 3 cannot therefore be interpreted in terms of the different conformation features presently detectable by available experimental methods.

  3. (1) H-NMR screening for the high-throughput determination of genotype and environmental effects on the content of asparagine in wheat grain.

    PubMed

    Corol, Delia I; Ravel, Catherine; Rakszegi, Marianna; Charmet, Gilles; Bedo, Zoltan; Beale, Michael H; Shewry, Peter R; Ward, Jane L

    2016-01-01

    Free asparagine in cereals is known to be the precursor of acrylamide, a neurotoxic and carcinogenic product formed during cooking processes. Thus, the development of crops with lower asparagine is of considerable interest to growers and the food industry. In this study, we describe the development and application of a rapid (1) H-NMR-based analysis of cereal flour, that is, suitable for quantifying asparagine levels, and hence acrylamide-forming potential, across large numbers of samples. The screen was applied to flour samples from 150 bread wheats grown at a single site in 2005, providing the largest sample set to date. Additionally, screening of 26 selected cultivars grown for two further years in the same location and in three additional European locations in the third year (2007) provided six widely different environments to allow estimation of the environmental (E) and G x E effects on asparagine levels. Asparagine concentrations in the 150 genotypes ranged from 0.32 to 1.56 mg/g dry matter in wholemeal wheat flours. Asparagine levels were correlated with plant height and therefore, due to recent breeding activities to produce semi-dwarf varieties, a negative relationship with the year of registration of the cultivar was also observed. The multisite study indicated that only 13% of the observed variation in asparagine levels was heritable, whilst the environmental contribution was 36% and the GxE component was 43%. Thus, compared to some other phenotypic traits, breeding for low asparagine wheats presents a difficult challenge. PMID:25816894

  4. Determination of pKa values of some novel benzimidazole salts by using a new approach with (1)H NMR spectroscopy.

    PubMed

    Mumcu, Akın; Küçükbay, Hasan

    2015-12-01

    Benzimidazoles and their derivatives including imidazole are studied widely because they exist in the structure of natural products and different drugs. pKa values are extremely important for drug discovery and improvement in order to determine pharmacokinetic and pharmacodynamic features such as permeation through biological barriers, interactions with the target area or side effects. Acid-base features (pKa ) have great importance not only for physiological characteristics but also for being used as a ligand or changing physico-chemical features by turning benzimidazoles into salts. Within the scope of this study, a variety of new benzimidazole salts were synthesized, and their characterizations were made by NMR spectroscopy, FTIR spectroscopy and element analysis techniques. The pKa values of synthesized benzimidazole salts were determined by inflection point approach using integration values obtained with (1) H NMR spectroscopy and Henderson-Hasselbalch analysis. pKa values of some benzimidazole salts were also determined by potentiometric methods in order to compare those of NMR spectroscopy results. PMID:26256272

  5. A 1H-NMR-Based Metabonomic Study on the Anti-Depressive Effect of the Total Alkaloid of Corydalis Rhizoma.

    PubMed

    Wu, Hongwei; Wang, Peng; Liu, Mengting; Tang, Liying; Fang, Jing; Zhao, Ye; Zhang, Yi; Li, Defeng; Xu, Haiyu; Yang, Hongjun

    2015-01-01

    Corydalis Rhizoma, named YuanHu in China, is the dried tuber of Corydalis yanhusuo W.T. Wang which is used in Traditional Chinese Medicine for pain relief and blood activation. Previous pharmacological studies showed that apart from analgesics, the alkaloids from YuanHu may be useful in the therapy of depression by acting on the GABA, dopamine and benzodiazepine receptors. In this study, the antidepressive effect of the total alkaloid of YuanHu (YHTA) was investigated in a chronic unpredictable mild stress (CUMS) rat model using 1H-NMR-based metabonomics. Plasma metabolic profiles were analyzed and multivariate data analysis was applied to discover the metabolic biomarkers in CUMS rats. Thirteen biomarkers of CUMS-introduced depression were identified, which are myo-inositol, glycerol, glycine, creatine, glutamine, glutamate, β-glucose, α-glucose, acetoacetate, 3-hydroxybutyrate, leucine and unsaturated lipids (L7, L9). Moreover, a metabolic network of the potential biomarkers in plasma perturbed by CUMS was detected. After YHTA treatment, clear separation between the model group and YHTA-treated group was achieved. The levels of all the abnormal metabolites mentioned above showed a tendency of restoration to normal levels. The results demonstrated the therapeutic efficacy of YHTA against depression and suggested that NMR-based metabolomics can provide a simple and easy tool for the evaluation of herbal therapeutics. PMID:26035102

  6. Metabolic responses of willow (Salix purpurea L.) leaves to mycorrhization as revealed by mass spectrometry and 1H NMR spectroscopy metabolite profiling

    PubMed Central

    Aliferis, Konstantinos A.; Chamoun, Rony; Jabaji, Suha

    2015-01-01

    The root system of most terrestrial plants form symbiotic interfaces with arbuscular mycorrhizal fungi (AMF), which are important for nutrient cycling and ecosystem sustainability. The elucidation of the undergoing changes in plants' metabolism during symbiosis is essential for understanding nutrient acquisition and for alleviation of soil stresses caused by environmental cues. Within this context, we have undertaken the task of recording the fluctuation of willow (Salix purpurea L.) leaf metabolome in response to AMF inoculation. The development of an advanced metabolomics/bioinformatics protocol employing mass spectrometry (MS) and 1H NMR analyzers combined with the in-house-built metabolite library for willow (http://willowmetabolib.research.mcgill.ca/index.html) are key components of the research. Analyses revealed that AMF inoculation of willow causes up-regulation of various biosynthetic pathways, among others, those of flavonoid, isoflavonoid, phenylpropanoid, and the chlorophyll and porphyrin pathways, which have well-established roles in plant physiology and are related to resistance against environmental stresses. The recorded fluctuation in the willow leaf metabolism is very likely to provide AMF-inoculated willows with a significant advantage compared to non-inoculated ones when they are exposed to stresses such as, high levels of soil pollutants. The discovered biomarkers of willow response to AMF inoculation and corresponding pathways could be exploited in biomarker-assisted selection of willow cultivars with superior phytoremediation capacity or genetic engineering programs. PMID:26042135

  7. Identification of endogenous metabolites in human sperm cells using proton nuclear magnetic resonance ((1) H-NMR) spectroscopy and gas chromatography-mass spectrometry (GC-MS).

    PubMed

    Paiva, C; Amaral, A; Rodriguez, M; Canyellas, N; Correig, X; Ballescà, J L; Ramalho-Santos, J; Oliva, R

    2015-05-01

    The objective of this study was to contribute to the first comprehensive metabolomic characterization of the human sperm cell through the application of two untargeted platforms based on proton nuclear magnetic resonance ((1) H-NMR) spectroscopy and gas chromatography coupled to mass spectrometry (GC-MS). Using these two complementary strategies, we were able to identify a total of 69 metabolites, of which 42 were identified using NMR, 27 using GC-MS and 4 by both techniques. The identity of some of these metabolites was further confirmed by two-dimensional (1) H-(1) H homonuclear correlation spectroscopy (COSY) and (1) H-(13) C heteronuclear single-quantum correlation (HSQC) spectroscopy. Most of the metabolites identified are reported here for the first time in mature human spermatozoa. The relationship between the metabolites identified and the previously reported sperm proteome was also explored. Interestingly, overrepresented pathways included not only the metabolism of carbohydrates, but also of lipids and lipoproteins. Of note, a large number of the metabolites identified belonged to the amino acids, peptides and analogues super class. The identification of this initial set of metabolites represents an important first step to further study their function in male gamete physiology and to explore potential reasons for dysfunction in future studies. We also demonstrate that the application of NMR and MS provides complementary results, thus constituting a promising strategy towards the completion of the human sperm cell metabolome. PMID:25854681

  8. (1)H NMR metabolomic study of auxotrophic starvation in yeast using Multivariate Curve Resolution-Alternating Least Squares for Pathway Analysis.

    PubMed

    Puig-Castellví, Francesc; Alfonso, Ignacio; Piña, Benjamin; Tauler, Romà

    2016-01-01

    Disruption of specific metabolic pathways constitutes the mode of action of many known toxicants and it is responsible for the adverse phenotypes associated to human genetic defects. Conversely, many industrial applications rely on metabolic alterations of diverse microorganisms, whereas many therapeutic drugs aim to selectively disrupt pathogens' metabolism. In this work we analyzed metabolic changes induced by auxotrophic starvation conditions in yeast in a non-targeted approach, using one-dimensional proton Nuclear Magnetic Resonance spectroscopy ((1)H NMR) and chemometric analyses. Analysis of the raw spectral datasets showed specific changes linked to the different stages during unrestricted yeast growth, as well as specific changes linked to each of the four tested starvation conditions (L-methionine, L-histidine, L-leucine and uracil). Analysis of changes in concentrations of more than 40 metabolites by Multivariate Curve Resolution - Alternating Least Squares (MCR-ALS) showed the normal progression of key metabolites during lag, exponential and stationary unrestricted growth phases, while reflecting the metabolic blockage induced by the starvation conditions. In this case, different metabolic intermediates accumulated over time, allowing identification of the different metabolic pathways specifically affected by each gene disruption. This synergy between NMR metabolomics and molecular biology may have clear implications for both genetic diagnostics and drug development. PMID:27485935

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

    PubMed

    Zhang, Sheng; Echegoyen, Luis

    2005-02-16

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

  10. 1H NMR metabolomic study of auxotrophic starvation in yeast using Multivariate Curve Resolution-Alternating Least Squares for Pathway Analysis

    PubMed Central

    Puig-Castellví, Francesc; Alfonso, Ignacio; Piña, Benjamin; Tauler, Romà

    2016-01-01

    Disruption of specific metabolic pathways constitutes the mode of action of many known toxicants and it is responsible for the adverse phenotypes associated to human genetic defects. Conversely, many industrial applications rely on metabolic alterations of diverse microorganisms, whereas many therapeutic drugs aim to selectively disrupt pathogens’ metabolism. In this work we analyzed metabolic changes induced by auxotrophic starvation conditions in yeast in a non-targeted approach, using one-dimensional proton Nuclear Magnetic Resonance spectroscopy (1H NMR) and chemometric analyses. Analysis of the raw spectral datasets showed specific changes linked to the different stages during unrestricted yeast growth, as well as specific changes linked to each of the four tested starvation conditions (L-methionine, L-histidine, L-leucine and uracil). Analysis of changes in concentrations of more than 40 metabolites by Multivariate Curve Resolution – Alternating Least Squares (MCR-ALS) showed the normal progression of key metabolites during lag, exponential and stationary unrestricted growth phases, while reflecting the metabolic blockage induced by the starvation conditions. In this case, different metabolic intermediates accumulated over time, allowing identification of the different metabolic pathways specifically affected by each gene disruption. This synergy between NMR metabolomics and molecular biology may have clear implications for both genetic diagnostics and drug development. PMID:27485935

  11. Interaction of anisole with 3α-hydroxy-5β-cholan-24-oic acid macrolides. Part 1. Comparative 1H NMR spectral investigation

    NASA Astrophysics Data System (ADS)

    Lappalainen, Kari V.; Kolehmainen, Erkki T.; Šaman, David

    1995-08-01

    1H NMR spectral investigation on the interaction of anisole (methoxybenzene) with five different (varying by ring size and substitution) cyclic 3α-hydroxy-5β-cholan-24-oic acid macrolides were performed. For 3α-hydroxy-5β-cholan-24-oic acid (lithocholic acid) macrolides (from triolide to pentolide) no effect was observed. In contrast, for 7α-trifluoroacetyloxy (7α-TFA) substituted lithocholate triolide obtained from chenodeoxycholic acid and for 12α-trifluoroacetyloxy (12α-TFA) substituted lithocholate triolide obtained from deoxycholic acid, clear site specific effects were observed. In the case of the 7α-TFA derivative, the aromatic guest causes the strongest up-field shift on the angular methyl 19 at the A/B ring junction of the steroid unit, and in 12α-TFA isomer the strongest effect is directed at the angular methyl 18 located at the C/D ring junction of the steroid skeleton. These findings are discussed in terms of steric factors and the size and flexibility of the cavity of the host molecule. Molecular mechanics is used in modeling the structures of three triolides.

  12. Minimalist Relativistic Force Field: Prediction of Proton-Proton Coupling Constants in (1)H NMR Spectra Is Perfected with NBO Hybridization Parameters.

    PubMed

    Kutateladze, Andrei G; Mukhina, Olga A

    2015-05-15

    We previously developed a reliable method for multiparametric scaling of Fermi contacts to achieve fast and accurate prediction of proton-proton spin-spin coupling constants (SSCC) in (1)H NMR. We now report that utilization of NBO hybridization coefficients for carbon atoms in the involved C-H bonds allows for a significant simplification of this parametric scheme, requiring only four general types of SSCCs: geminal, vicinal, 1,3-, and long-range constants. The method is optimized for inexpensive B3LYP/6-31G(d) molecular geometries. A new DU8 basis set, based on a training set of 475 experimental spin-spin coupling constants, is developed for hydrogen and common non-hydrogen atoms (Li, B, C, N, O, F, Si, P, S, Cl, Se, Br, I) to calculate Fermi contacts. On a test set of 919 SSCCs from a diverse collection of natural products and complex synthetic molecules the method gave excellent accuracy of 0.29 Hz (rmsd) with the maximum unsigned error not exceeding 1 Hz. PMID:25885091

  13. Sequence-specific 1H-NMR assignment and secondary structure of black mamba dendrotoxin I, a highly selective blocker of voltage-gated potassium channels.

    PubMed

    Foray, M F; Lancelin, J M; Hollecker, M; Marion, D

    1993-02-01

    The secondary structure of dendrotoxin I, an important constituent of the venom of the African black mamba snake Dendroaspis polylepis polylepis, was determined in aqueous solution by two-dimensional methods. Complete sequence-specific 1H-NMR assignment was obtained with the exception of the backbone amide proton of Gly39 and Cys40. Dendrotoxin I is based on a central antiparallel beta-sheet and two small helices located at the N- and the C-terminal extremities. These secondary-structural units occur at exactly the same places in the amino acid sequence as those of bovine pancreatic trypsin inhibitor (BPTI), with which dendrotoxin I shares 33% sequence similarity. According to the disulfide-bridge positions and the long-range NOE observed these secondary-structural elements fold in a similar manner to BPTI. This similarity allows an hypothesis according to which dendrotoxin I could derive from an ancestral Künitz-type proteinase inhibitor. This ancestor would have been heavily mutated at amino acid positions not critical for gross structure. The spatial locations of the solvent-exposed amino acids concerned could therefore serve as a guideline for interpretation of the structure/activity relationship of dendrotoxin I for the blockage of voltage-sensitive potassium channels of which dendrotoxin I is a strong inhibitor. The possible connections with other polypeptide toxins that block related ion currents is discussed. PMID:7679640

  14. Molecular Mechanics and Variable-Temperature 1H NMR Studies on N,N-Diethyl-m-toluamide. An Undergraduate NMR and Molecular Modeling Experiment

    NASA Astrophysics Data System (ADS)

    Jensen, Bruce L.; Fort, Raymond C., Jr.

    2001-04-01

    A combination of molecular modeling and variable-temperature NMR experiments is used to analyze the barrier to rotation about the amide bond of N,N-diethyl-m-toluamide (DEET). This approach utilizes the ability of computers to calculate the potential energy of a set of conformations obtained from a dihedral drive around the N-CO bond. The results of this experiment demonstrate a substantial barrier of 15.9 kcal/mol. These data are applied to a set of 1H NMR spectra taken over a range of temperatures from 9 to 85 °C. At very low temperatures the conformation is "locked" and the spectrum displays two sets of triplets and two sets of quartets for the two nonequivalent ethyl groups. However, at high temperature the rapid rotation about the amide linkage produces only one quartet and one triplet, characteristic of two indistinguishable ethyl groups. The experiment offers students hands-on experience with two important laboratory instruments and allows for both qualitative and quantitative analysis of the data. This experiment is scheduled to coincide with lecture discussion of NMR spectroscopy, after the fundamentals of bond rotation have been presented.

  15. 1H NMR investigation of the hetero-association of phenanthridine dyes with Daunomycin: effect of substitution of amino with azido groups in the dye chromophore

    NASA Astrophysics Data System (ADS)

    Veselkov, Dennis A.; Karawajew, Leonid; Veselkov, Alexei N.; Davies, David B.

    1H NMR spectroscopy at 500 Mhz has been used to determine the structures and thermodynamics in aqueous salt solution of the hetero-association of Daunomycin (DAU) with a series of phenanthridine dyes having different numbers of amino/azido groups in the chromophore, together with the self-association of the phenthridine dyes under the same solution conditions (0.1 M phosphate buffer, pD 7.1, 298 K). The NMR measurements have been analyzed using statistical-thermodynamical models of both self-association and hetero- association in which no limitation is set on the size of molecular stacks. In this work the magnitudes of the self-association parameters of Ethidium Bromide (EB) and its azido-derivatives, 8-azido-Ethidium Bromide (EMB) and 3,8-diazido-Ethidium Chloride (EDC), show a successive decrease with mono- and di-substitition of the 3,8-amino groups of EB. A similar pattern is observed for the equilibrium constants for hetero-association of the phenanthridines with DAU. The thermodynamical and structural parameters of hetero-association of the phenanthridines with DAU are consistent with an intermolecular hydrogen bond between the 3,8 amino-groups of EB and the 9MeCO group of DAU contributing to the stability of the hetero-complex in aqueous solution.

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

    PubMed

    Gogna, Navdeep; Hamid, Neda; Dorai, Kavita

    2015-11-10

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

  17. sup 1 H NMR studies of DNA recognition by the glucocorticoid receptor: Complex of the DNA binding domain with a half-site response element

    SciTech Connect

    Remerowski, M.L.; Kellenbach, E.; Boelens, R.; Kaptein, R. ); van der Marel, G.A.; van Boom, J.H. ); Maler, B.A.; Yamamoto, K.R. )

    1991-12-17

    The complex of the rat glucocorticoid receptor (GR) DNA binding domain (DBD) and half-site sequence of the consensus glucocorticoid response element (GRE) has been studied by two-dimensional {sup 1}H NMR spectroscopy. The DNA fragment is a 10 base-pair oligonucleotide, 5{prime}d(GCTGTTCTGC)3{prime}{center dot}5{prime}d-(GCAGAACAGC)3{prime}, containing the stronger binding GRE half-site hexamer, with GC base pairs at each end. The 93-residue GR-DBD contains an 86-residue segment corresponding to residues 440-525 of the rat GR. Eleven NOE cross peaks between the protein and DNA have been identified, and changes in the chemical shift of the DNA protons upon complex formation have been analyzed. Using these protein-DNA contact points, it can be concluded that (1) the 'recognition helix' formed by residues C460-E469 lies in the major groove of the DNA; (2) the GR-DBD is oriented on the GRE half-site such that residues A477-D481, forming the so-called D-loop, are available for protein-protein interaction in the GR-DBD dimer on the intact consensus GRE; and (3) the 5-methyl of the second thymine in the half-site and valine 462 interact, confirming indirect evidence that both play an important role in GR-DBD DNA binding.

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

    ERIC Educational Resources Information Center

    Angawi, Rihab F.

    2014-01-01

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

  19. Description of the behavior of dichloroalkanes-containing solutions with three [bXmpy][BF4] isomers, using the experimental information of thermodynamic properties, 1H NMR spectral and the COSMO-RS-methodology.

    PubMed

    Fernández, Luis; Ortega, Juan; Palomar, José; Toledo, Francisco; Marrero, Elena

    2015-02-26

    This work studies the binaries of 1-butyl-X-methylpyridinium tetrafluoroborate [bXmpy][BF4] (X = 2, 3, and 4) with four 1,ω-dichloroalkanes, ω = 1-4, using the results obtained for the mixing properties h(E) and v(E) at two temperatures. The three isomers of the ionic liquid (IL) are weakly miscible with the 1,ω-dichloroalkanes when ω ≥ 5 and moderately soluble for ω = 4. The v(E)s of all the binaries present contractive effects, v(E) < 0, which are more pronounced with increasing temperature; the variation in v(E) with ω is positive, although this changes after ω = 4 due to problems of immiscibility. The energetic effects of the mixing process are exothermic in the solutions with the shorter dichloroalkanes, ω = 1 and 2, and this effect increases slightly with temperature. However, mildly exothermic effects are found in the binaries with larger halides, where (dh(E)/dT) > 0. The experimental data are correlated with a suitable equation. The study is completed with (1)H NMR measurements of both the pure compounds and some of the solutions, which showed minor diamagnetic shifts with increasing IL compositions, related to the anisotropy of the pyridine ring. The variation in h(E) with ω for a same IL, due to an increase in the contact surfaces, is related to the reduction in polarity which, in turn, depends on the smaller chemical shifts of the pure dihalide compounds. The COSMO-RS method determines the energetic effects of the mixing process and predicts an exothermic contribution for the electrostatic Misfit-interaction which is quantitatively very similar for the three IL isomers. The differences proposed by the model are mainly reflected in the van der Waals interactions, which are exothermic and clearly influenced by the position of the methylene group in the IL. The contribution made by hydrogen bonds is negligible. PMID:25642731

  20. Metabolomic analysis of glycerophospholipid signatures of inflammation treated with non-steroidal anti-inflammatory drugs-induced-RAW264.7 cells using (1)H NMR and U-HPLC/Q-TOF-MS.

    PubMed

    Wu, Xia; Cao, Han; Zhao, Lifang; Song, Jianao; She, Yuqi; Feng, Yifan

    2016-08-15

    Non-destructive proton nuclear magnetic resonance ((1)H NMR) spectroscopy and highly sensitive ultra-performance liquid chromatography quadrupole time-of-flight mass spectrometry (U-HPLC/Q-TOF-MS) coupled to data processing methods were applied to analyze the metabolic profiling changes of glycerophospholipids (GPLs) in RAW264.7 cells from inflammation to prognosis. Analysis of (1)H NMR was shown that the models were grouped successfully, illustrating that all of them had significant differences. Based on the highly simple, accurate, non-targeted and non-destructively advantages of (1)H NMR, it could be used as a new screening tool of anti-inflammatory drugs in the metabolic profiling of GPLs. 58 GPLs were identified by U-HPLC/Q-TOF-MS, and 19 components were firstly identified in this study compared with our previous results. In addition, ten potential biomarkers were proved, of which phosphatidylcholine (PC) (16:0/18:1) and (18:0/18:1) changed consistently in three drug-induced groups and might be the important biomarkers. Compared with (1)H NMR, U-HPLC/Q-TOF-MS showed higher sensitivity and specificity and was more suitable for the determination of biomarkers apart from the deficiency of time-consuming sample preparation steps and unambiguous metabolite identification. Therefore, it is feasible to analyze the changes of GPLs during inflammation by combining (1)H NMR spectroscopy with U-HPLC/Q-TOF-MS. The metabolic profiling of GPLs provides valuable evidence for inflammation diagnosis and prognosis, and might unravel the mechanisms involved in inflammation progression. PMID:27371817

  1. Synthesis and conformational analysis by 1H NMR and restrained molecular dynamics simulations of the cyclic decapeptide [Ser-Tyr-Ser-Met-Glu-His-Phe-Arg-Trp-Gly].

    PubMed

    Buono, R A; Kucharczyk, N; Neuenschwander, M; Kemmink, J; Hwang, L Y; Fauchère, J L; Venanzi, C A

    1996-06-01

    The design of enzyme mimics with therapeutic and industrial applications has interested both experimental and computational chemists for several decades. Recent advances in the computational methodology of restrained molecular dynamics, used in conjunction with data obtained from two-dimensional 1H NMR spectroscopy, make it a promising method to study peptide and protein structure and function. Several issues, however, need to be addressed in order to assess the validity of this method for its explanatory and predictive value. Among the issues addressed in this study are: the accuracy and generizability of the GROMOS peptide molecular mechanics force field; the effect of inclusion of solvent on the simulations; and the effect of different types of restraining algorithms on the computational results. The decapeptide Ser-Tyr-Ser-Met-Glu-His-Phe-Arg-Trp-Gly, which corresponds to the sequence of ACTH1-10, has been synthesized, cyclized, and studied by two-dimensional 1H NMR spectroscopy. Restrained molecular dynamics (RMD) and time-averaged restrained molecular dynamics (TARMD) simulations were carried out on four different distance-geometry starting structures in order to determine and contrast the behavior of cyclic ACTH1-10 in vacuum and in solution. For the RMD simulations, the structures did not fit the NOE data well, even at high values of the restraining potential. The TARMD simulation method, however, was able to give structures that fit the NOE data at high values of the restraining potential. In both cases, inclusion of explicit solvent molecules in the simulation had little effect on the quality of the fit, although it was found to dampen the motion of the cyclic peptide. For both simulation techniques, the number and size of the NOE violations increased as the restraining potential approached zero. This is due, presumably, to inadequacies in the force field. Additional TARMD vacuum-phase simulations, run with a larger memory length or with a larger sampling

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

    PubMed Central

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

    2015-01-01

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

  3. (1)H NMR-based metabolomics investigation of Daphnia magna responses to sub-lethal exposure to arsenic, copper and lithium.

    PubMed

    Nagato, Edward G; D'eon, Jessica C; Lankadurai, Brian P; Poirier, David G; Reiner, Eric J; Simpson, Andre J; Simpson, Myrna J

    2013-09-01

    Metal and metalloid contamination constitutes a major concern in aquatic ecosystems. Thus it is important to find rapid and reliable indicators of metal stress to aquatic organisms. In this study, we tested the use of (1)H nuclear magnetic resonance (NMR) - based metabolomics to examine the response of Daphnia magna neonates after a 48h exposure to sub-lethal concentrations of arsenic (49μgL(-1)), copper (12.4μgL(-1)) or lithium (1150μgL(-1)). Metabolomic responses for all conditions were compared to a control using principal component analysis (PCA) and metabolites that contributed to the variation between the exposures and the control condition were identified and quantified. The PCA showed that copper and lithium exposures result in statistically significant metabolite variations from the control. Contributing to this variation was a number of amino acids such as: phenylalanine, leucine, lysine, glutamine, glycine, alanine, methionine and glutamine as well as the nucleobase uracil and osmolyte glycerophosphocholine. The similarities in metabolome changes suggest that lithium has an analogous mode of toxicity to that of copper, and may be impairing energy production and ionoregulation. The PCA also showed that arsenic exposure resulted in a metabolic shift in comparison to the control population but this change was not statistically significant. However, significant changes in specific metabolites such as alanine and lysine were observed, suggesting that energy metabolism is indeed disrupted. This research demonstrates that (1)H NMR-based metabolomics is a viable platform for discerning metabolomic changes and mode of toxicity of D. magna in response to metal stressors in the environment. PMID:23732010

  4. A comparison of metabolite extraction strategies for 1H-NMR-based metabolic profiling using mature leaf tissue from the model plant Arabidopsis thaliana.

    PubMed

    Kaiser, Kayla A; Barding, Gregory A; Larive, Cynthia K

    2009-12-01

    Metabolite analysis is recognized as an important facet of systems biology, however complete metabolome characterization has not been realized due to challenges in sample preparation, inherent instrumental limitations and the labor intensive task of data interpretation. This work aims to compare several commonly used metabolite extraction strategies for their effect on the (1)H nuclear magnetic resonance (NMR) metabolic profile of extracts of the model plant Arabidopsis thaliana. Extractions were carried out on aliquots from a pool of homogenized plant tissue using CD(3)CN/D(2)O, buffered D(2)O, perchloric acid in D(2)O, CD(3)OD/D(2)O and CD(3)OD/D(2)O/CDCl(3) as the extraction solvents. The effects of lyophilization as a sample pretreatment, solvent evaporation and extract fractionation for removal of interfering species were studied. Representative spectra are presented for qualitative interpretation. Analytical reproducibility was evaluated by principal components analysis. Perchloric acid facilitated acid-catalyzed cleavage of sucrose, further complicating biological interpretation of the resulting metabolite profile. The solvent system CD(3)OD/D(2)O/CDCl(3) gave the least reproducible results in our hands. D(2)O extracts suffered from poor stability probably due to contamination by soluble enzymes, which were not denatured in this solvent. CD(3)CN/D(2)O extracts showed greater stability than D(2)O alone, but problems were encountered due to degradation of (1)H NMR spectral resolution during lengthy acquisitions due to partial phase separation. In addition, this solvent system produced spectra with significant contamination by lipids that obscured spectral regions containing the resonances of the aliphatic amino acids. These problems were solved by speedvacuuming the CD(3)CN/D(2)O extract and reconstituting in D(2)O solution. PMID:19551810

  5. FTIR, magnetic, 1H NMR spectral and thermal studies of some chelates of caproic acid: inhibitory effect on different kinds of bacteria.

    PubMed

    Refat, Moamen S; El-Korashy, Sabry A; Kumar, Deo Nandan; Ahmed, Ahmed S

    2008-06-01

    A convenient method for the preparation of complexes of the Cr3+, Mn2+, Fe3+, Co2+, Ni2+, Zn2+, ZrO2+, UO2(2+), Zr4+ and Th4+ ions with caproic acid (Hcap) is reported and this has enabled 10 complexes of caproate anion to be formulated: [Cr(cap)3].5H2O, [Mn(cap)2(H2O)2], [Fe(cap)3].12H2O, [Co(cap)2(H2O)2].4H2O, [Ni(cap)2(H2O)2].3H2O, [Zn(cap)2], [ZrO(cap)2].3H2O, [UO2(cap)(NO3)], [Zr(cap)2(Cl)2] and [Th(cap)4]. These new complexes were synthesized and characterized by elemental analysis, molar conductivity, magnetic measurements, spectral methods (mid infrared, 1H NMR and UV-vis spectra) and simultaneous thermal analysis (TG and DTG) techniques. It has been found from the elemental analysis as well as thermal studies that the caproate ligand behaves as bidentate ligand and forming chelates with 1:1 (metal:ligand) stoichiometry for UO2(2+), 1:2 for (Mn2+, Co2+, Ni2+, Zn2+, ZrO2+ and Zr4+), 1:3 stoichiometry for (Cr3+ and Fe3+) and 1:4 for Th4+ caproate complexes, respectively, as bidentate chelating. The molar conductance measurements proved that the caproate complexes are non-electrolytes. The kinetic thermodynamic parameters such as: E*, DeltaH*, DeltaS* and DeltaG* are estimated from the DTG curves. The antibacterial activity of the caproic acid and their complexes was evaluated against some gram positive/negative bacteria. PMID:17766172

  6. (1) H-NMR relaxometric studies of interaction between apoptosis specific MRI paramagnetic contrast agents and micellar models of apoptotic cells.

    PubMed

    Van Koninckxloo, Aurore; Henoumont, Céline; Laurent, Sophie; Muller, Robert N; Vander Elst, Luce

    2016-07-01

    (1) H-NMR was previously used to analyze the interaction between peptides (E3 and R826) selected by phage display to target apoptotic cells and phospholipidic models of these cells. In order to avoid the use of apoptotic cells and to obtain a fast evaluation of the efficiency of the potential MRI contrast agents obtained by grafting these peptides and their scramble analogs on a paramagnetic gadolinium complex, their proton relaxometric behavior was investigated in the presence of micelles mimicking healthy and apoptotic cells. Their preferential interaction with 1,2-dipalmitoyl-sn-glycero-3-phospho-l-serine micelles mimicking apoptotic cells as compared with 1,2-dipalmitoyl-sn-glycero-3-phosphocholine micelles modeling healthy cells was shown by nuclear magnetic relaxation dispersion profiles and the enhancement of the transverse proton relaxation rates at 60 MHz. The association constant values confirm the stronger interaction of the selected conjugated peptides (Ka Gd-PMN-E3(gadolinium 2,2',2'',2'''-[((4-carboxy)pyridine-2,6-diyl)bis(methylenenitrilo)]-tetrakis acetate) grafted with E3 peptide): 2.43 10(4)  m(-1) ; Ka Gd-DTPA-R826(gadolinium ((1-p-isothiocyanatobenzyl)-diethylenetriaminepentaacetate) grafted with R826 peptide): 2.91 10(4)  m(-1) ) as compared with their conjugated scrambles (Ka Gd-PMN-E3sc(gadolinium 2,2',2'',2'''-[((4-carboxy)pyridine-2,6-diyl)bis(methylenenitrilo)]-tetrakis acetate) grafted with E3 scramble peptide): 0.18 10(4)  m(-1) ; Ka Gd-DTPA-R826sc(gadolinium ((1-p-isothiocyanatobenzyl)-diethylenetriaminepentaacetate) grafted with R826 scramble peptide): 0.32 10(4)  m(-1) ) even if the conjugation of E3 and R826 seems to decrease their interaction. Copyright © 2015 John Wiley & Sons, Ltd. PMID:26647764

  7. Practical aspects of Lee Goldburg based CRAMPS techniques for high-resolution 1H NMR spectroscopy in solids: Implementation and applications

    NASA Astrophysics Data System (ADS)

    Coelho, Cristina; Rocha, João; Madhu, P. K.; Mafra, Luís

    2008-10-01

    Elucidating the local environment of the hydrogen atoms is an important problem in materials science. Because 1H spectra in solid-state nuclear magnetic resonance (NMR) suffer from low resolution due to homogeneous broadening, even under magic-angle spinning (MAS), information of chemical interest may only be obtained using certain high-resolution 1H MAS techniques. 1H Lee-Goldburg (LG) CRAMPS (Combined Rotation And Multiple-Pulse Spectroscopy) methods are particularly well suited for studying inorganic-organic hybrid materials, rich in 1H nuclei. However, setting up CRAMPS experiments is time-consuming and not entirely trivial, facts that have discouraged their widespread use by materials scientists. To change this status quo, here we describe and discuss some important aspects of the experimental implementation of CRAMPS techniques based on LG decoupling schemes, such as FSLG (Frequency Switched), and windowed and windowless PMLG (Phase Modulated). In particular, we discuss the influence on the quality of the 1H NMR spectra of the different parameters at play, for example LG (Lee-Goldburg) pulses, radio-frequency ( rf) phase, frequency switching, and pulse imperfections, using glycine and adamantane as model compounds. The efficiency and robustness of the different LG-decoupling schemes is then illustrated on the following materials: organo-phosphorus ligand, N-(phosphonomethyl)iminodiacetic acid [H 4pmida] [I], and inorganic-organic hybrid materials (C 4H 12N 2)[Ge 2(pmida) 2OH 2]·4H 2O [II] and (C 2H 5NH 3)[Ti(H 1.5PO 4)(PO 4)] 2·H 2O [III].

  8. Serum metabonomics study of the hepatoprotective effect of Corydalis saxicola Bunting on carbon tetrachloride-induced acute hepatotoxicity in rats by (1)H NMR analysis.

    PubMed

    Liang, Yong-Hong; Tang, Chao-Ling; Lu, Shi-Yin; Cheng, Bang; Wu, Fang; Chen, Zhao-Ni; Song, Fangming; Ruan, Jun-Xiang; Zhang, Hong-Ye; Song, Hui; Zheng, Hua; Su, Zhi-Heng

    2016-09-10

    Corydalis saxicola Bunting (CS), a traditional Chinese folk medicine, has been effectively used for treating liver disease in Zhuang nationality in South China. However, the exact hepatoprotective mechanism of CS was still looking forward to further elucidation by far. In present work, metabonomic study of biochemical changes in the serum of carbon tetrachloride (CCl4)-induced acute liver injury rats after CS treatment were performed using proton nuclear magnetic resonance ((1)H-NMR) analysis. Metabolic profiling by means of principal components analysis (PCA) and partial least squares-discriminate analysis (PLS-DA) indicated that the metabolic perturbation caused by CCl4 was reduced by CS treatment. A total of 9 metabolites including isoleucine (1), lactate (2), alanine (3), glutamine (4), acetone (5), succinate (6), phosphocholine (7), d-glucose (8) and glycerol (9) were considered as potential biomarkers involved in the development of CCl4-induced acute liver injury. According to pathway analysis by metabolites identified and correlation network construction by Pearson's correlation coefficency matrix, alanine, aspartate and glutamate metabolism and glycerolipid metabolism were recognized as the most influenced metabolic pathways associated with CCl4 injury. As a result, notably, deviations of metabolites 1, 3, 4, 7 and 9 in the process of CCl4-induced acute liver injury were improved by CS treatment, which suggested that CS mediated synergistically abnormalities of the metabolic pathways, composed of alanine, aspartate and glutamate metabolism and glycerolipid metabolism. In this study, it was the first report to investigate the hepatoprotective effect of the CS based on metabonomics strategy, which may be a potentially powerful tool to interpret the action mechanism of traditional Chinese folk medicines. PMID:27399344

  9. Hyper-mobility of water around actin filaments revealed using pulse-field gradient spin-echo {sup 1}H NMR and fluorescence spectroscopy

    SciTech Connect

    Wazawa, Tetsuichi; Sagawa, Takashi; Ogawa, Tsubasa; Morimoto, Nobuyuki; Kodama, Takao; Suzuki, Makoto

    2011-01-28

    Research highlights: {yields} Translationally hyper-mobile water has been detected around actin filaments. {yields} Translationally hyper-mobile water is formed upon polymerization of actin. {yields} Low water viscosity was found around F-actin using fluorescence anisotropy. {yields} Formation of hyper-mobile water may explain endothermic actin polymerization. -- Abstract: This paper reports that water molecules around F-actin, a polymerized form of actin, are more mobile than those around G-actin or in bulk water. A measurement using pulse-field gradient spin-echo {sup 1}H NMR showed that the self-diffusion coefficient of water in aqueous F-actin solution increased with actin concentration by {approx}5%, whereas that in G-actin solution was close to that of pure water. This indicates that an F-actin/water interaction is responsible for the high self-diffusion of water. The local viscosity around actin was also investigated by fluorescence measurements of Cy3, a fluorescent dye, conjugated to Cys 374 of actin. The steady-state fluorescence anisotropy of Cy3 attached to F-actin was 0.270, which was lower than that for G-actin, 0.334. Taking into account the fluorescence lifetimes of the Cy3 bound to actin, their rotational correlation times were estimated to be 3.8 and 9.1 ns for F- and G-actin, respectively. This indicates that Cy3 bound to F-actin rotates more freely than that bound to G-actin, and therefore the local water viscosity is lower around F-actin than around G-actin.

  10. Influence of substrate modification and C-terminal truncation on the active site structure of substrate-bound heme oxygenase from Neisseriae meningitidis; A 1H NMR study†

    PubMed Central

    Peng, Dungeng; Satterlee, James D.; Ma, Li-Hua; Dallas, Jerry L.; Smith, Kevin M.; Zhang, Xuhong; Sato, Michihiko; La Mar, Gerd N.

    2011-01-01

    Heme oxygenase, HO, from the pathogenic bacterium N. meningitidis, NmHO, which secures host iron, shares many properties with mammalian HOs, but also exhibits some key differences. The crystal structure appears more compact and the crystal-undetected C-terminus interacts with substrate in solution. The unique nature of substrate-protein, specifically pyrrole-I/II-helix-2, peripheral interactions in NmHO are probed by 2D 1H NMR to reveal unique structural features controlling substrate orientation. The thermodynamics of substrate orientational isomerism are mapped for substrates with individual vinyl → methyl → hydrogen substitutions and with enzyme C-terminal deletions. NmHO exhibits significantly stronger orientational preference, reflecting much stronger and selective pyrrole-I/II interactions with the protein matrix, than in mammalian HOs. Thus, replacing bulky vinyls with hydrogens results in a 180° rotation of substrate about the α,γ-meso axis in the active site. A "collapse" of the substrate pocket as substrate size decreases is reflected in movement of helix-2 toward the substrate as indicated by significant and selective increased NOESY cross peak intensity, increase in steric Fe-CN tilt reflected in the orientation of the major magnetic axis, and decrease in steric constraints controlling the rate of aromatic ring reorientation. The active site of NmHO appears "stressed" for native protohemin and its "collapse" upon replacing vinyls by hydrogen leads to a factor ~102 increase in substrate affinity. Interaction of the C-terminus with the active site destabilizes the crystallographic protohemin orientation by ~0.7 kcal/mol, which is consistent with optimizing the His207-Asp27 H-bond. Implications of the active site "stress" for product release are discussed. PMID:21870860

  11. Zebrafish as a Model for Systems Medicine R&D: Rethinking the Metabolic Effects of Carrier Solvents and Culture Buffers Determined by (1)H NMR Metabolomics.

    PubMed

    Akhtar, Muhammad T; Mushtaq, Mian Y; Verpoorte, Robert; Richardson, Michael K; Choi, Young H

    2016-01-01

    Zebrafish is a frequently employed model organism in systems medicine and biomarker discovery. A crosscutting fundamental question, and one that has been overlooked in the field, is the "system-wide" (omics) effects induced in zebrafish by metabolic solvents and culture buffers. Indeed, any bioactivity or toxicity test requires that the target compounds are dissolved in an appropriate nonpolar solvent or aqueous media. It is important to know whether the solvent or the buffer itself has an effect on the zebrafish model organism. We evaluated the effects of two organic carrier solvents used in research with zebrafish, as well as in drug screening: dimethyl sulfoxide (DMSO) and ethanol, and two commonly used aqueous buffers (egg water and Hank's balanced salt solution). The effects of three concentrations (0.01, 0.1, and 1%) of DMSO and ethanol were tested in the 5-day-old zebrafish embryo using proton nuclear magnetic resonance ((1)H NMR) based metabolomics. DMSO (1% and 0.1%, but not 0.01%) exposure significantly decreased the levels of adenosine triphosphate (ATP), betaine, alanine, histidine, lactate, acetate, and creatine (p < 0.05). By contrast, ethanol exposure did not alter the embryos' metabolome at any concentration tested. The two different aqueous media noted above impacted the zebrafish embryo metabolome as evidenced by changes in valine, alanine, lactate, acetate, betaine, glycine, glutamate, adenosine triphosphate, and histidine. These results show that DMSO has greater effects on the embryo metabolome than ethanol, and thus is used with caution as a carrier solvent in zebrafish biomarker research and oral medicine. Moreover, the DMSO concentration should not be higher than 0.01%. Careful attention is also warranted for the use of the buffers egg water and Hank's balanced salt solution in zebrafish. In conclusion, as zebrafish is widely used as a model organism in life sciences, metabolome changes induced by solvents and culture buffers warrant further

  12. Assignment of 1H NMR resonances of histidine and other aromatic residues in met-, cyano-, oxy-, and (carbon monoxy)myoglobins.

    PubMed

    Carver, J A; Bradbury, J H

    1984-10-01

    The resolved 1H NMR resonances of the aromatic region in the 270-MHz NMR spectrum of sperm whale, horse, and pig metmyoglobin (metMb) have been assigned, including the observable H-2 and H-4 histidine resonances, the tryptophan H-2 resonances, and upfield-shifted resonances from one tyrosine residue. The use of different Mb species, carboxymethylation, and matching of pK values allows the assignment of the H-4 resonances, which agree in only three cases out of seven with scalar-correlated two-dimensional NMR spectroscopy assignments by others. The conversion to hydroxymyoglobin at high pH involves rearrangements throughout the molecule and is observed by many assigned residues. In sperm whale ferric cyanomyoglobin, nine H-2 and eight H-4 histidine resonances have been assigned, including the His-97 H-2 resonance and tyrosine resonances from residues 103 and 146. The hyperfine-shifted resonances from heme and near-heme protons observe a shift with a pK = 5.3 +/- 0.3 (probably due to deprotonation of His-97, pK = 5.6) and another shift at pK = 10.8 +/- 0.3. The spectrum of high-spin ferrous sperm whale deoxymyoglobin is very similar to that of metMb, which allows the assignment of seven surface histidine H-2 and H-4 resonances and also resonances from the two tryptophan residues and one tyrosine. In diamagnetic sperm whale (carbon monoxy)myoglobin (COMb), 10 His H-2 and 11 His H-4 resonances are observed, and 8 H-2 and 9 H-4 resonances are assigned, including His-64 H-4, the distal histidine. This important resonance is not observed in sperm whale oxymyoglobin, which in general shows very similar titration curves to COMb. Histidine-36 shows unusual titration behavior in the paramagnetic derivatives but normal behavior in the diamagnetic derivatives, which is discussed in the accompanying paper [Bradbury, J. H., & Carver, J. A. (1984) Biochemistry (following paper in this issue)]. PMID:6498166

  13. Quality assessment of fluoxetine and fluvoxamine pharmaceutical formulations purchased in different countries or via the Internet by 19F and 2D DOSY 1H NMR.

    PubMed

    Trefi, Saleh; Gilard, Véronique; Balayssac, Stéphane; Malet-Martino, Myriam; Martino, Robert

    2008-03-13

    A simple and selective (19)F NMR method has been validated for the quantitation of fluoxetine (FLX) and fluvoxamine (FLV) in methanol solutions and in human plasma and urine. The regression equations for FLX and FLV showed a good linearity in the range of 1.4-620 microg mL(-1) (3.3 x 10(-6)-1.8 x 10(-3) mol L(-1)) with a limit of detection of approximately 0.5 microg mL(-1) (1.3 x 10(-6) mol L(-1)) and a limit of quantification of approximately 2 microg mL(-1) (4.6 x 10(-6) mol L(-1)). The precision of the assay depends on the concentrations and is comprised between 1.5 and 9.5% for a range of concentrations between 1.2 x 10(-3) and 3.2 x 10(-6) mol L(-1). The accuracy evaluated through recovery studies ranged from approximately 96 to 103% in methanol solutions and in urine, and from approximately 93 to 104% in plasma, with standard deviations <7.5%. The low sensitivity of the method precludes its use for the assay of these antidepressants in biofluids at least at therapeutic doses as the ranges of FLX and FLV plasma levels are 0.15-0.5 microg mL(-1) and 0.15-0.25 microg mL(-1), respectively. The method was applied successfully to the determination of FLX and FLV contents in pharmaceutical samples (brand-named and generic) purchased in several countries or via the Internet. All the commercial formulations contain the active ingredient in the range 94-103% of stated concentration. A "signature" of the formulations (solid and liquid) was obtained with 2D Diffusion-Ordered SpectroscopY (DOSY) (1)H NMR which allowed the characterisation of the active ingredient and excipients present in the formulations studied. Finally, the DOSY separation of FLX and FLV whose molecular weights are very close was obtained by using beta-cyclodextrin as host-guest complexing agent. PMID:18206329

  14. Quantitative 1H NMR metabolomics reveals extensive metabolic reprogramming of primary and secondary metabolism in elicitor-treated opium poppy cell cultures

    PubMed Central

    Zulak, Katherine G; Weljie, Aalim M; Vogel, Hans J; Facchini, Peter J

    2008-01-01

    Background Opium poppy (Papaver somniferum) produces a diverse array of bioactive benzylisoquinoline alkaloids and has emerged as a model system to study plant alkaloid metabolism. The plant is cultivated as the only commercial source of the narcotic analgesics morphine and codeine, but also produces many other alkaloids including the antimicrobial agent sanguinarine. Modulations in plant secondary metabolism as a result of environmental perturbations are often associated with the altered regulation of other metabolic pathways. As a key component of our functional genomics platform for opium poppy we have used proton nuclear magnetic resonance (1H NMR) metabolomics to investigate the interplay between primary and secondary metabolism in cultured opium poppy cells treated with a fungal elicitor. Results Metabolite fingerprinting and compound-specific profiling showed the extensive reprogramming of primary metabolic pathways in association with the induction of alkaloid biosynthesis in response to elicitor treatment. Using Chenomx NMR Suite v. 4.6, a software package capable of identifying and quantifying individual compounds based on their respective signature spectra, the levels of 42 diverse metabolites were monitored over a 100-hour time course in control and elicitor-treated opium poppy cell cultures. Overall, detectable and dynamic changes in the metabolome of elicitor-treated cells, especially in cellular pools of carbohydrates, organic acids and non-protein amino acids were detected within 5 hours after elicitor treatment. The metabolome of control cultures also showed substantial modulations 80 hours after the start of the time course, particularly in the levels of amino acids and phospholipid pathway intermediates. Specific flux modulations were detected throughout primary metabolism, including glycolysis, the tricarboxylic acid cycle, nitrogen assimilation, phospholipid/fatty acid synthesis and the shikimate pathway, all of which generate secondary

  15. Use of on-flow LC/1H NMR for the study of an antioxidant fraction from Orophea enneandra and isolation of a polyacetylene, lignans, and a tocopherol derivative.

    PubMed

    Cavin, A; Potterat, O; Wolfender, J L; Hostettmann, K; Dyatmyko, W

    1998-12-01

    The CH2Cl2 extract of the leaves of Orophea enneandra displayed antifungal, antioxidant, and radical scavenging properties in bioautographic TLC assays. To obtain rapid information on the active compounds, on-flow LC/1H NMR and LC/UV/MS analyses of the antioxidant fraction were performed. The on-line information led rapidly to the partial identification of three closely related lignans, one tocopherol derivative, and one polyacetylene. This approach necessitated, however, large quantities to be injected to obtain satisfactory on-flow LC/1H NMR spectra, and isolation of the compounds was necessary to obtain complete NMR data. These compounds were isolated and identified as (-)-phylligenin (1), (-)-eudesmin (2), (-)-epieudesmin (3), polycerasoidol (4), and oropheic acid (5), a new polyacetylene. Their activities against the 2, 2-diphenyl-1-picrylhydrazyl radical and the fungus Cladosporium cucumerinum were investigated. This paper indicates the possibilities and limits of on-flow LC/1H NMR in this type of study. PMID:9868150

  16. 1H NMR metabolic profiling of cod (Gadus morhua) larvae: potential effects of temperature and diet composition during early developmental stages

    PubMed Central

    Chauton, Matilde Skogen; Galloway, Trina Falck; Kjørsvik, Elin; Størseth, Trond Røvik; Puvanendran, Velmurugu; van der Meeren, Terje; Karlsen, Ørjan; Rønnestad, Ivar; Hamre, Kristin

    2015-01-01

    ABSTRACT Marine aquaculture offers a great source of protein for the increasing human population, and farming of, for example, Atlantic salmon is a global industry. Atlantic cod farming however, is an example of a promising industry where the potential is not yet realized. Research has revealed that a major bottleneck to successful farming of cod is poor quality of the larvae and juveniles. A large research program was designed to increase our understanding of how environmental factors such as temperature and nutrition affects cod larvae development. Data on larvae growth and development were used together with nuclear magnetic resonance. The NMR data indicated that the temperature influenced the metabolome of the larvae; differences were related to osmolytes such as betaine/TMAO, the amino acid taurine, and creatine and lactate which reflect muscle activity. The larvae were fed Artemia from stage 2, and this was probably reflected in a high taurine content of older larvae. Larvae fed with copepods in the nutrition experiment also displayed a high taurine content, together with higher creatine and betaine/TMAO content. Data on the cod larvae metabolome should be coupled to data on gene expression, in order to identify events which are regulated on the genetic level versus regulation resulting from temperature or nutrition during development, to fully understand how the environment affects larval development. PMID:26545964

  17. Size Determination of Porosity Inclusions in an Organic Solid Material by (1)H NMR Diffusion and SEM-FIB Experiments: The TATB Case.

    PubMed

    Palmas, Pascal; Botzanowski, Thomas; Guerain, Mathieu; Forzy, Alexandre; Bruneton, Eric; Delrio, Guillaume

    2016-05-01

    An original approach has been presented to characterize the local geometry of pores containing protonated small molecule impurities in organic materials. It was here applied in TATB (1,3,5-triamino-2,4,6-trinitrobenzene) powder material to investigate the porosity able to enclose water molecules. The presence of such defects may have a significant impact on TATB-based compositions mechanical properties, efficiency, and shock sensitivity. Apparent self-diffusion coefficients measured on the low water signal residue were consistent with highly mobile species experiencing restricted diffusion in confined porosities. Applying the methodology commonly used for the characterization of porous systems, we could demonstrate for the first time that pores, with an average size in the 3-5 μm range, were already present in the native TATB powder before any formulation and that these pores were closed and filled with water/NH4Cl solutions. The presence of such macrocavities was further confirmed by analyzing the TATB 3D porous structure using the SEM-FIB dual-beam technique at the scale of particle fractions. Calculation of the pore volumes was performed to deduce pore size distributions assuming spherical cavities. A volume-weighted average size was calculated showing a satisfactory agreement with NMR results and a suitable complementarity of the two approaches. PMID:27054804

  18. A magnetoelectric composite based signal generator

    NASA Astrophysics Data System (ADS)

    Fetisov, Y. K.; Serov, V. N.; Fetisov, L. Y.; Makovkin, S. A.; Viehland, D.; Srinivasan, G.

    2016-05-01

    Self-oscillations in an active loop consisting of a wide-band amplifier and a magnetoelectric composite in the feedback circuit have been observed. The composite with a ferroelectric lead zirconate titanate bimorph and ferromagnetic Metglas serves as a resonator that determines the frequency of oscillations and provides the feedback voltage. Under amplitude balance and phase matching conditions, the device generated signals at 2.3 kHz, at the bending resonance frequency of the composite. The oscillations were observed over a specific range of magnetic bias H. The shape of the signal generated is dependent on electrical circuit parameters and magnitude and orientation of H.

  19. Elaborated 1H NMR study for the ligitional behavior of two thiosemicarbazide derivatives towards some heavy metals (Sn(II), Sb(III), Pb(II) and Bi(III)), thermal, antibacterial and antifungal studies

    NASA Astrophysics Data System (ADS)

    El-Metwaly, Nashwa M.; Refat, Moamen S.

    2011-10-01

    A new series of heavy metal complexes are prepared. Sn(II), Sb(III), Pb(II) and Bi(III) are the metal ions used in complexation with two thiosemicarbazide ligands. The IR and 1H NMR spectra of the free ligands display their presence in thiole-thione forms coincide with each other. The IR spectra of the complexes support the presence of 2:2 molar ratio (M:HL) with HL 1 ligand and 1:1 beside 1:2 with HL 2. The ligand coordinates as bi molecules in some complexes and displays two tautomer forms at the same complex molecule 1H NMR spectra of Sn(II) and Sb(III) complexes were done and comes coincide with IR data. The electronic spectral analysis displays a lower shift appearance in n → π* charge transfer band in most isolated complexes. As well as, a new band is shinned in visible region with Sb(III), Bi(III) complexes and Sn(II)-HL 2. This band is pointed to its use in spectrophotometric analysis for these metal ions. The TG analysis for all isolated compounds was briefly discussed. The molecular modeling parameters support the stability of thiole form of the free ligands in comparing with their thiones by a small difference. The antibacterial and antifungal activities were studied against some organisms and reveal the priority of most investigated complexes.

  20. Thermochromism in nickel(II) complexes: thermal, solid state 1H NMR and single crystal X-ray analysis of bis-( N, N-dimethyl-1,2-ethanediamine) nickel(II) perchlorate

    NASA Astrophysics Data System (ADS)

    Koner, Subratanath; Tsutake, Masaru; Nagasawa, Isoroku; Ikeda, Ryuichi; Saha, Pratap K.; Mukherjee, Alok K.; Banerjee, Surajit

    2002-08-01

    The complex bis-( N, N-dimethyl-1,2-ethanediamine) nickel(II) perchlorate undergoes a first-order thermochromic phase transition at ca. 476 K, changing its color from orange to red. The room temperature X-ray crystal structure determination showed that the nickel ion possesses a square-planar geometry with two five membered chelate rings, in the δλ conformation, forming the NiN 4 chromophore. The broad-line 1H NMR indicates the onset of a dynamic disorder of diamine chelate rings at the phase transition temperature region, while T1 measurement of 1H affords the activation energy of the puckering metal chelate rings to be 26 kJ mol -1. The electronic spectrum revealed that a weakening of ligand field around the nickel is associated with the phase transition.

  1. Conformational Preferences of N,N-Dimethylsuccinamate as a Function of Alkali and Alkaline Earth Metal Salts: Experimental Studies in DMSO and Water As Determined by 1H NMR Spectroscopy

    PubMed Central

    2015-01-01

    The fraction of gauche conformers of N,N-dimethylsuccinamic acid (1) and its Li+, Na+, K+, Mg2+, Ca2+, and N(Bu)4+ salts were estimated in DMSO and D2O solution by comparing the experimental vicinal proton–proton couplings determined by 1H NMR spectroscopy with those calculated using the Haasnoot, de Leeuw, and Altona (HLA) equation. In DMSO, the gauche preferences were found to increase with decreasing Ahrens ionic radius of the metal counterion. The same trend was not seen in D2O, where the gauche fraction for all of the metallic salts were estimated to be approximately statistical or less. This highlights the importance of metal chelation on the conformation of organic molecules in polar aprotic media, which has implications for protein folding. PMID:24506581

  2. Characterization of vanadium oxide catalysts supported on TiO{sub 2}-ZrO{sub 2} by solid-state {sup 51}V and {sup 1}H NMR spectroscopy

    SciTech Connect

    Reddy, B.M.; Reddy, E.P.; Srinivas, S.T.

    1992-08-20

    A series of TiO{sub 2}-ZrO{sub 2} mixed oxide supported vanadia catalysts with various V{sub 2}O{sub 5} loadings ranging from 1 to 16 wt % were prepared by a wet impregnation method and were characterized by means of solid-state {sup 51}V and {sup 1}H NMR spectroscopic techniques. The solid-state {sup 51}V NMR spectra of V{sub 2}O{sub 5}/TiO{sub 2}-ZrO{sub 2} catalysts reveal the existence of two types of dispersed surface vanadium oxide complexes in a tetrahedral oxygen environment at lower vanadium loadings adn a third three-dimensional crystalline V{sub 2}O{sub 5} in distorted octahedral environment at higher vanadium contents. The proton NMR results provide evidence for the existence of metal oxide support interaction through the support hydroxyl groups. 33 regs., 4 figs.

  3. The Serum Metabolite Response to Diet Intervention with Probiotic Acidified Milk in Irritable Bowel Syndrome Patients Is Indistinguishable from that of Non-Probiotic Acidified Milk by 1H NMR-Based Metabonomic Analysis

    PubMed Central

    Pedersen, Simon M. M.; Nielsen, Niels Chr.; Andersen, Henrik J.; Olsson, Johan; Simrén, Magnus; Öhman, Lena; Svensson, Ulla; Malmendal, Anders; Bertram, Hanne C.

    2010-01-01

    The effects of a probiotic acidified milk product on the blood serum metabolite profile of patients suffering from Irritable Bowel Syndrome (IBS) compared to a non-probiotic acidified milk product was investigated using 1H NMR metabonomics. For eight weeks, IBS patients consumed 0.4 L per day of a probiotic fermented milk product or non-probiotic acidified milk. Both diets resulted in elevated levels of blood serum L-lactate and 3-hydroxybutyrate. Our results showed identical effects of acidified milk consumption independent of probiotic addition. A similar result was previously obtained in a questionnaire-based evaluation of symptom relief. A specific probiotic effect is thus absent both in the patient subjective symptom evaluations and at the blood serum metabolite level. However, there was no correspondence between symptom relief and metabolite response on the patient level. PMID:22254002

  4. Urinary excretion and metabolism of miglustat and valproate in patients with Niemann-Pick type C1 disease: One- and two-dimensional solution-state (1)H NMR studies.

    PubMed

    Probert, Fay; Ruiz-Rodado, Victor; Zhang, Xiaoyu; te Vruchte, Danielle; Claridge, Tim D W; Edgar, Mark; Tocchio, Anna Zonato; Lachmann, Robin H; Platt, Frances M; Grootveld, Martin

    2016-01-01

    Niemann-Pick type C1 (NP-C1) disease is a neurodegenerative lysosomal storage disease for which the only approved therapy is miglustat (MGS). In this study we explored the applications and value of both one- and two-dimensional high-resolution NMR analysis strategies to the detection and quantification of MGS and its potential metabolites in urine samples collected from NP-C1 disease patients (n=47), and also applied these techniques to the analysis of the anticonvulsant drug valproate and one of its major metabolites in ca. 30% of these samples (i.e. from those who were also receiving this agent for the control of epileptic seizures). A combination of high-resolution 1D and 2D TOCSY/NOESY techniques confirmed the identity of MGS in the urinary (1)H NMR profiles of NP-C1 patients treated with this agent (n=25), and its quantification was readily achievable via electronic integration of selected 1D resonance intensities. However, this analysis provided little or no evidence for its metabolism in vivo, observations consistent with those acquired in corresponding experiments performed involving an in vitro microsomal system. Contrastingly, the major valproate metabolite 1-O-valproyl-β-glucuronide was readily detectable and quantifiable in 14/47 of the urine samples investigated, despite some resonance overlap problems (identification of this agent was confirmed by experiments involving equilibration of these samples with β-glucuronidase, a process liberating free valproate). In order to facilitate and validate the detection of MGS in urine specimens, full assignments of the (1)H NMR spectra of MGS in both buffered aqueous (pH 7.10) and deuterated methanol solvent systems were also made. The pharmacological and bioanalytical significance of data acquired are discussed, with special reference to the advantages offered by high-resolution NMR analysis. PMID:26397207

  5. Solid-state structure and solution conformation of the nootropic agent N[2-( N,N-Diisopropylamino)ethyl]-2-oxo-1-pyrrolidinacetamide sulphate. X-ray and homonuclear two-dimensional 1H NMR studies

    NASA Astrophysics Data System (ADS)

    Bandoli, Giuliano; Nicolini, Marino; Pappalardo, Giuseppe C.; Grassi, Antonio; Perly, Bruno

    1987-04-01

    The crystal and molecular structure of the nootropic agent N-[2-( N,N-diisopropyl-amino)ethyl]-2-oxo-1-pyrrolidinacetamide sulphate was determined by X-ray analysis. The conformational properties in the solution state were deduced from the 1H-NMR spectrum run in 2H 2O at 500 MHz. Spectral assignments were made with the aid of the COSY 45 shift correlation experiment. Crystals were triclinic with unit cell dimensions a = 13.410(10), b = 11.382(8), c = 6.697(4) », α = 83.80(3), β = 88.61(3)and γ = 72.25(6)° ; space group Poverline1. The structure was determined from 1047 three-dimensional counter data and refined to a value of 7.5% for the conventional discrepancy factor R. One molecule of the solvent acetonitrile is incorporated per two of the (C 14H 28N 3O 2) +-(HSO 4) -. The five-membered heterocyclic ring is in an envelope ( Cs) conformation and the "flap" atom deviates by 0.31 » from the plane of the other four. This plane forms a dihedral angle of 71.4° with the amide group, with the CO fragment directed toward the ring. All bond angles and distances are in good agreement with expected standard values. A strong OH⋯O intermolecular bond (2.61 ») links the cation of the hydrogen-sulphate anion, while the loosely held MeCN molecule is trapped in the polar pockets. The molecular conformation in the solid was compared with results from 1H NMR spectral analysis which showed that in solution wide torsional oscillations can occur about the bonds of the chain bonded to the N(1) atom.

  6. The binding of manganese(II) and zinc(II) to the synthetic oligonucleotide d(C-G-C-G-A-A-T-T-C-G-C-G)2. A 1H NMR study.

    PubMed

    Frøystein, N A; Sletten, E

    1991-03-01

    The interaction of the synthetic oligonucleotide d(C-G-C-G-A-A-T-T-C-G-C-G)2 with two different transition-metal ions has been investigated in aqueous solution by means of 1H NMR spectroscopy. The effects on the DNA due to the presence of manganese(II) or zinc(II) have been monitored by observing the paramagnetic broadening and diamagnetic shifts of the non-exchangeable proton resonance lines, respectively. The 1H NMR spectra acquired during the course of the manganese(II) titration show very distinct broadening effects on certain DNA resonance lines. Primarily, the H8 resonance of G4 is affected, but also the H5 and H6 resonances of C3 are clearly affected by the metal. The results imply that the binding of manganese(II) to DNA is sequence specific. The 1H spectra obtained during the zinc(II) titration reveal diamagnetic shift effects which largely conform with the paramagnetic broadening effects due to the presence of manganese(II), although this picture is somewhat more complex. The H8 resonance of G4 displays a clearly visible high-field shift, while for the other guanosine H8 protons this effect is absent. The H1' and H2' protons of C3 show an effect of similar strength, although in the opposite direction, while H5 and H6 of C3 are only slightly affected. Local differences in the structure of the DNA and the basicities of potential binding sites on different base steps in the sequence might account for the observed sequence selectivity. PMID:2039665

  7. Heme Orientation of Cavity Mutant Hemoglobins (His F8 → Gly) in Either α or β Subunits: Circular Dichroism, (1) H NMR, and Resonance Raman Studies.

    PubMed

    Nagai, Masako; Nagai, Yukifumi; Aki, Yayoi; Sakurai, Hiroshi; Mizusawa, Naoki; Ogura, Takashi; Kitagawa, Teizo; Yamamoto, Yasuhiko; Nagatomo, Shigenori

    2016-08-01

    Native human adult hemoglobin (Hb A) has mostly normal orientation of heme, whereas recombinant Hb A (rHb A) expressed in E. coli contains both normal and reversed orientations of heme. Hb A with the normal heme exhibits positive circular dichroism (CD) bands at both the Soret and 260-nm regions, while rHb A with the reversed heme shows a negative Soret and decreased 260-nm CD bands. In order to examine involvement of the proximal histidine (His F8) of either α or β subunits in determining the heme orientation, we prepared two cavity mutant Hbs, rHb(αH87G) and rHb(βH92G), with substitution of glycine for His F8 in the presence of imidazole. CD spectra of both cavity mutant Hbs did not show a negative Soret band, but instead exhibited positive bands with strong intensity at the both Soret and 260-nm regions, suggesting that the reversed heme scarcely exists in the cavity mutant Hbs. We confirmed by (1) H NMR and resonance Raman (RR) spectroscopies that the cavity mutant Hbs have mainly the normal heme orientation in both the mutated and native subunits. These results indicate that the heme Fe-His F8 linkage in both α and β subunits influences the heme orientation, and that the heme orientation of one type of subunit is related to the heme orientation of the complementary subunits to be the same. The present study showed that CD and RR spectroscopies also provided powerful tools for the examination of the heme rotational disorder of Hb A, in addition to the usual (1) H NMR technique. Chirality 28:585-592, 2016. © 2016 Wiley Periodicals, Inc. PMID:27427792

  8. "Omics" Prospective Monitoring of Bariatric Surgery: Roux-En-Y Gastric Bypass Outcomes Using Mixed-Meal Tolerance Test and Time-Resolved (1)H NMR-Based Metabolomics.

    PubMed

    Lopes, Thiago I B; Geloneze, Bruno; Pareja, José C; Calixto, Antônio R; Ferreira, Márcia M C; Marsaioli, Anita J

    2016-07-01

    Roux-en-Y gastric bypass (RYGB) surgery goes beyond weight loss to induce early beneficial hormonal changes that favor glycemic control. In this prospective study, ten obese subjects diagnosed with type 2 diabetes underwent bariatric surgery. Mixed-meal tolerance test was performed before and 12 months after RYGB, and the outcomes were investigated by a time-resolved hydrogen nuclear magnetic resonance ((1)H NMR)-based metabolomics. To the best of our knowledge, no previous omics-driven study has used time-resolved (1)H NMR-based metabolomics to investigate bariatric surgery outcomes. Our results presented here show a significant decrease in glucose levels after bariatric surgery (from 159.80 ± 61.43 to 100.00 ± 22.94 mg/dL), demonstrating type 2 diabetes remission (p < 0.05). The metabolic profile indicated lower levels of lactate, alanine, and branched chain amino acids for the operated subject at fasting state after the surgery. However, soon after food ingestion, the levels of these metabolites increased faster in operated than in nonoperated subjects. The lipoprotein profile achieved before and after RYGB at fasting was also significantly different, but converging 180 min after food ingestion. For example, the very low-density lipoprotein, low-density lipoprotein, N-acetyl-glycoproteins, and unsaturated lipid levels decreased after RYGB, while phosphatidylcholine and high-density lipoprotein increased. This study provides important insights on RYGB surgery and attendant type 2 diabetes outcomes using an "omics" systems science approach. Further research on metabolomic correlates of RYGB surgery in larger study samples is called for. PMID:27428253

  9. Primary and secondary biomass burning aerosols determined by proton nuclear magnetic resonance (1H-NMR) spectroscopy during the 2008 EUCAARI campaign in the Po Valley (Italy)

    NASA Astrophysics Data System (ADS)

    Paglione, M.; Saarikoski, S.; Carbone, S.; Hillamo, R.; Facchini, M. C.; Finessi, E.; Giulianelli, L.; Carbone, C.; Fuzzi, S.; Moretti, F.; Tagliavini, E.; Swietlicki, E.; Eriksson Stenström, K.; Prévôt, A. S. H.; Massoli, P.; Canaragatna, M.; Worsnop, D.; Decesari, S.

    2014-05-01

    Atmospheric organic aerosols are generally classified as primary and secondary (POA and SOA) according to their formation processes. An actual separation, however, is challenging when the timescales of emission and gas-to-particle formation overlap. The presence of SOA formation in biomass burning plumes leads to scientific questions about whether the oxidized fraction of biomass burning aerosol is rather of secondary or primary origin, as some studies would suggest, and about the chemical compositions of oxidized biomass burning POA and SOA. In this study, we apply nuclear magnetic resonance (NMR) spectroscopy to investigate the functional group composition of fresh and aged biomass burning aerosols during an intensive field campaign in the Po Valley, Italy. The campaign was part of the EUCAARI project and was held at the rural station of San Pietro Capofiume in spring 2008. Factor analysis applied to the set of NMR spectra was used to apportion the wood burning contribution and other organic carbon (OC) source contributions, including aliphatic amines. Our NMR results, referred to the polar, water-soluble fraction of OC, show that fresh wood burning particles are composed of polyols and aromatic compounds, with a sharp resemblance to wood burning POA produced in wood stoves, while aged samples are clearly depleted of alcohols and are enriched in aliphatic acids with a smaller contribution of aromatic compounds. The comparison with biomass burning organic aerosols (BBOA) determined by high-resolution aerosol mass spectrometry (HR-TOF-AMS) at the site shows only a partial overlap between NMR BB-POA and AMS BBOA, which can be explained by either the inability of BBOA to capture all BB-POA composition, especially the alcohol fraction, or the fact that BBOA account for insoluble organic compounds unmeasured by the NMR. Therefore, an unambiguous composition for biomass burning POA could not be derived from this study, with NMR analysis indicating a higher O / C ratio

  10. Structural comparison of complexes of methotrexate analogues with Lactobacillus casei dihydrofolate reductase by two-dimensional /sup 1/H NMR at 500 MHz

    SciTech Connect

    Hammond, S.J.; Birdsall, B.; Feeney, J.; Searle, M.S.; Roberts, G.C.K.; Cheung, H.T.A.

    1987-12-29

    The authors have used two-dimensional (2D) NMR methods to examine complexes of Lactobacillus casei dihydrofolate reductase and methotrexate (MTX) analogues having structural modifications of the benzoyl ring and also the glutamic acid moiety. Assignments of the /sup 1/H signals in the spectra of the various complexes were made by comparison of their 2D spectra with those complexes containing methotrexate where we have previously assigned resonances from 32 of the 162 amino acid residues. In the complexes formed with the dihalomethotrexate analogues, the glutamic acid and pteridine ring moieties were shown to bind to the enzyme in a manner similar to that found in the methotrexate-enzyme complex. Perturbations in /sup 1/H chemical shifts of protons in Phe-49, Leu-54, and Leu-27 and the methotrexate H7 and NMe protons were observed in the different complexes and were accounted for by changes in orientation of the benzoyl ring in the various complexes. Binding of oxidized or reduced coenzyme to the binary complexes did not result in different shifts for Leu-27, Leu-54, or Leu-19 protons, and thus, the orientation of the benzoyl ring of the methotrexate analogues is not perturbed greatly by the presence of either oxidized or reduced coenzyme. In the complex with the ..gamma..-monoamide analog, the /sup 1/H signals of assigned residues in the protein had almost identical shifts with the corresponding protons in the methotrexate-enzyme complex for all residues except His-28 and, to a lesser extent, Leu-27. This indicates that while the His-28 interaction with the MTX ..gamma..-CO/sub 2//sup -/ is no longer present in this complex with the ..gamma..-amide, there has not been a major change in the overall structure of the two complexes. This behavior contrasts to that of the ..cap alpha..-amide complex where /sup 1/H signals from protons in several amino acid residues are different compared with their values in the complex formed with methotrexate.

  11. Standardization of solvent extracts from Onopordum acanthium fruits by GC-MS, HPLC-UV/DAD, HPLC-TQMS and 1H-NMR and evaluation of their inhibitory effects on the expression of IL-8 and E-selectin in immortalized endothelial cells (HUVECtert).

    PubMed

    Daci, Armond; Gold-Binder, Markus; Garzon, Davide; Patea, Alessio; Beretta, Giangiacomo

    2014-07-01

    In this work we have characterized and standardized the solvent extracts of the fruits of Onopordum acanthium, a plant widely distributed from Europe to Asia and used in different traditional medicines. Fruits were extracted with methanol (ME) and n-hexane (HE) and the extract compositions determined by GC-MS, HPLC-UV/DAD, HPLC-TQMS and 1H NMR spectroscopy. Anti-inflammatory activity (IL-8 and E-selectin, qPCR and ELISA) was investigated in HUVECtert cells stimulated with TNF-alpha and LPS. Arctiin and isochlorogenic acid were found in ME (87 +/- 2%, w/w, and 10.2 +/- 0.2%, w/w; 38.0 +/- 3.2 mg/gFRUITS and 3.5 +/- 0.4 mg/gFRUITS) and (ii) paraffins in the HE (195.6 +/- 5.6 mg/g). A dose dependent (from 15 to 40 microgME/mL corresponding to 20-75 microM arctiin) inhibition of E-selectin and of the induction of IL-8 was induced by LPS. The results of this study support the use of O. acanthium fruits in traditional medicine as an anti-inflammatory agent and for cancer prevention and treatment. PMID:25230500

  12. Synthesis, spectral analysis (FT-IR, 1H NMR, 13C NMR and UV-visible) and quantum chemical studies on molecular geometry, NBO, NLO, chemical reactivity and thermodynamic properties of novel 2-amino-4-(4-(dimethylamino)phenyl)-5-oxo-6-phenyl-5,6-dihydro-4H-pyrano[3,2-c]quinoline-3-carbonitrile

    NASA Astrophysics Data System (ADS)

    Fatma, Shaheen; Bishnoi, Abha; Verma, Anil Kumar

    2015-09-01

    In the present study novel 2-amino-4-(4-(dimethylamino)phenyl)-5-oxo-6-phenyl-5,6-dihydro-4H-pyrano[3,2-c]quinoline-3-carbonitrile was synthesized and characterized by FT-IR, 1H NMR, 13C NMR, UV-visible spectroscopy and mass spectral analysis. The chemical calculations were done by DFT level of theory using Becke3-Lee-Yang-Parr (B3LYP) and Coulomb Attenuating Method (CAM-B3LYP)/6-31G(d,p) basis set. 1H, 13C chemical shifts and vibrational wavenumbers were calculated and good correlation with the experimental data has been accomplished. UV-Visible spectrum of the molecule was recorded in the region 200-500 nm and the electronic properties and composition were obtained using Time Dependent Density Functional Theory (TDDFT) method. Hyperconjugative interactions were studied with the help of natural bond orbital analysis. Electric dipole moment, polarizability and first static hyperpolarizability values have been calculated. The results show that the title compound possesses nonlinear optical behavior with non-zero values. The thermodynamic properties of the compound were calculated at different temperatures. The local reactivity descriptors show that C(7) is most reactive site for nucleophilic attack.

  13. 1H NMR-based lipidomics of rodent fur: species-specific lipid profiles and SCD1 inhibitor-related dermal toxicity[S

    PubMed Central

    Khandelwal, Purnima; Stryker, Steven; Chao, Hannguang; Aranibar, Nelly; Lawrence, R. Michael; Madireddi, Malavi; Zhao, Wenjun; Chen, Luping; Reily, Michael D.

    2014-01-01

    A method is described that allows noninvasive identification and quantitative assessment of lipid classes present in sebaceous excretions in rodents. The method relies on direct high-field proton NMR analysis of common group lipid protons in deuterated organic solvent extracts of fur. Extracts from as little as 15 mg of fur from rat, mouse, and hamster provided acceptable results on a 600 MHz NMR equipped with a cryogenically cooled proton-observe probe. In rats, sex- and age-related differences in lipid composition are larger than differences in fur collected from various body regions within an individual and much larger than interanimal differences in age- and sex-matched specimens. The utility of this method to noninvasively monitor drug-induced sebaceous gland atrophy in rodents is demonstrated in rats dosed with a stearoyl-CoA desaturase 1 (SCD1) inhibitor. In this model, a 35% reduction in sebum lipids, extracted from fur, was observed. Finally, structural elucidation of cholesta-7,24-dien-3β-ol ester as the most prominent, previously unidentified sebum sterol ester in male Syrian hamsters is described. The utility of this method for drug and cosmetic safety and efficacy assessment is discussed. PMID:24755647

  14. An investigation of the sol-gel process in ionic liquid-silica gels by time resolved Raman and 1H NMR spectroscopy.

    PubMed

    Martinelli, Anna; Nordstierna, Lars

    2012-10-14

    We report, by employing time resolved Raman and nuclear magnetic resonance (NMR) spectroscopy, on the gelation process in ionogels. These are prepared from a non-aqueous sol-gel reaction in the ionic liquid 1-hexyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide (C(1)C(6)ImTFSI). Raman and NMR spectroscopies are complementarily used to decipher the chemical reactions that occur during synthesis and to clarify the state of the ionic liquid up to, and well beyond, gelation. We find that the ionic liquid concentration affects both the reaction rate and the gelation time (t(gel)). In addition, NMR and Raman data reveal inherently different roles of the cation and the anion in the gelation process. While the oscillating behavior of the TFSI Raman signature at ~740 cm(-1) is mainly an effect of solvation and chemical composition, the evolution of the relative chemical shifts (Δδ) of different hydrogen atoms on the imidazolium correlates with gelation, as does the width of the chemical shift of -OH containing groups (δ(OH)). We also observe that in the confined state the TFSI anion preferably adopts the cisoid conformation and experiences a stronger ion-ion interaction. PMID:22910853

  15. Uniform procedure of (1)H NMR analysis of rat urine and toxicometabonomics Part II: comparison of NMR profiles for classification of hepatotoxicity.

    PubMed

    Schoonen, Willem G E J; Kloks, Cathelijne P A M; Ploemen, Jan-Peter H T M; Smit, Martin J; Zandberg, Pieter; Horbach, G Jean; Mellema, Jan-Remt; Thijssen-Vanzuylen, Carol; Tas, Albert C; van Nesselrooij, Joop H J; Vogels, Jack T W E

    2007-07-01

    A procedure of nuclear magnetic resonance (NMR) urinalysis using pattern recognition is proposed for early detection of toxicity of investigational compounds in rats. The method is applied to detect toxicity upon administration of 13 toxic reference compounds and one nontoxic control compound (mianserine) in rats. The toxic compounds are expected to induce necrosis (bromobenzene, paracetamol, carbon tetrachloride, iproniazid, isoniazid, thioacetamide), cholestasis (alpha-naphthylisothiocyanate (ANIT), chlorpromazine, ethinylestradiol, methyltestosterone, ibuprofen), or steatosis (phenobarbital, tetracycline). Animals were treated daily for 2 or 4 days except for paracetamol and bromobenzene (1 and 2 days) and carbon tetrachloride (1 day only). Urine was collected 24 h after the first and second treatment. The animals were sacrificed 24 h after the last treatment, and NMR data were compared with liver histopathology as well as blood and urine biochemistry. Pathology and biochemistry showed marked toxicity in the liver at high doses of bromobenzene, paracetamol, carbon tetrachloride, ANIT, and ibuprofen. Thioacetamide and chlorpromazine showed less extensive changes, while the influences of iproniazid, isoniazid, phenobarbital, ethinylestradiol, and tetracycline on the toxic parameters were marginal or for methyltestosterone and mianserine negligible. NMR spectroscopy revealed significant changes upon dosing in 88 NMR biomarker signals preselected with the Procrustus Rotation method on principal component discriminant analysis (PCDA) plots. Further evaluation of the specific changes led to the identification of biomarker patterns for the specific types of liver toxicity. Comparison of our rat NMR PCDA data with histopathological changes reported in humans and/or rats suggests that rat NMR urinalysis can be used to predict hepatotoxicity. PMID:17420222

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

    PubMed

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

    2016-07-01

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

  17. Glycyl-histidyl-lysine (GHK) is a quencher of alpha,beta-4-hydroxy-trans-2-nonenal: a comparison with carnosine. insights into the mechanism of reaction by electrospray ionization mass spectrometry, 1H NMR, and computational techniques.

    PubMed

    Beretta, Giangiacomo; Artali, Roberto; Regazzoni, Luca; Panigati, Monica; Facino, Roberto Maffei

    2007-09-01

    Histidine-containing oligopeptides are currently studied as detoxifying agents against cytotoxic alpha,beta-unsaturated aldehydes (prototype: 4-hydroxy-2-nonenal, HNE), electrophilic end products formed by decomposition of omega-6 polyunsaturated fatty acids, associated with severe pathologies such as diabetes, nephropathy, retinopathy, and neurodegenerative diseases. This study evaluated the quenching reaction against HNE of the endogenous tripeptide l-glycyl- l-histidyl- l-lysine (GHK), an oligopeptide discovered to be a growth-modulating factor and also a strong activator of wound healing. We first evaluated the HNE consumption (50 microM, HPLC-UVDAD method) in the presence of GHK (1 mM) in physiomimetic conditions (phosphate buffer, pH 7.4) and confirmed GHK/HNE adduct formation by mass spectrometric analysis (ESI-MS/MS) and (1)H NMR analyses. These results indicated that GHK was an effective quencher of HNE, although significantly less potent than the reference compound carnosine, and that HNE modulation by GHK can contribute to the satisfactory outcome of the wound-healing process. In the second part of the study, we investigated the quenching reaction between GHK and HNE, in parallel to carnosine, using (1)H NMR and computational analyses. At a mechanistic level, this explained the different reactivity of the two peptides: (i) The greater stability of the macrocyclic intermediate HNE/carnosine was compared to HNE/GHK. (ii) GHK in solution has a quasi-folded conformation due to the interaction of four intramolecular hydrogen bonds, three of which need to be broken for the transition state to form (energy barrier, approximately 20 kcal/mol). By contrast, carnosine, with an extended conformation and only one hydrogen bond, requires less energy to reach the transition state ( approximately 7 kcal/mol). (iii) The different stereoelectronic features of the transition state lead to the intramolecular Michael reaction, that is, the favorable superimposition of

  18. Locations of local anesthetic dibucaine in model membranes and the interaction between dibucaine and a Na+ channel inactivation gate peptide as studied by 2H- and 1H-NMR spectroscopies.

    PubMed Central

    Kuroda, Y; Ogawa, M; Nasu, H; Terashima, M; Kasahara, M; Kiyama, Y; Wakita, M; Fujiwara, Y; Fujii, N; Nakagawa, T

    1996-01-01

    To study the molecular mechanisms of local anesthesia, locations of local anesthetic dibucaine in model membranes and the interactions of dibucaine with a Na+ channel inactivation gate peptide have been studied by 2H- and 1H-NMR spectroscopies. The 2H-NMR spectra of dibucaine-d9 and dibucaine-d1, which are deuterated at the butoxy group and at the 3 position in its quinoline ring, respectively, have been observed in multilamellar dispersions of the lipid mixture composed of phosphatidylcholine, phosphatidylserine, and phosphatidylethanolamine. 2H-NMR spectra of deuterated palmitic acids incorporated, as a probe, into the lipid mixture containing cholesterol have also been observed. An order parameter, SCD, for each carbon segment was calculated from the observed quadrupole splittings. Combining these results, we concluded that first, the butoxy group of dibucaine is penetrating between the acyl chains of lipids in the model membranes, and second, the quinoline ring of dibucaine is located at the polar region of lipids but not at the hydrophobic acyl chain moiety. These results mean that dibucaine is situated in a favorable position that permits it to interact with a cluster of hydrophobic amino acids (Ile-Phe-Met) within the intracellular linker between domains III and IV of Na+ channel protein, which functions as an inactivation gate. To confirm whether the dibucaine molecule at the surface region of lipids can really interact with the hydrophobic amino acids, we synthesized a model peptide that includes the hydrophobic amino acids (Ac-GGQDIFMTEEQK-OH, MP-1), the amino acid sequence of which corresponds to the linker part of rat brain type IIA Na+ channel, and the one in which Phe has been substituted by Gln (MP-2), and measured 1H-NMR spectra in both phosphate buffer and phosphatidylserine liposomes. It was found that the quinoline ring of dibucaine can interact with the aromatic ring of Phe by stacking of the rings; moreover, the interaction can be reinforced by

  19. 1H NMR study of the dynamics of the pH modulation of axial coordination in Aplysia limacina (Val(E7)) and sperm whale double mutant His(E7)-->Val,Thr(E10)-->Arg metmyoglobin.

    PubMed

    Qin, J; Pande, U; La Mar, G N; Ascoli, F; Ascenzi, P; Cutruzzolá, F; Travaglini-Allocatelli, C; Brunori, M

    1993-11-15

    The molecular and electronic structure, thermodynamics, dynamics, and mechanism of interconversion of the pH-modulated reversible equilibria of Aplysia limacina metmyoglobin, (metMb), have been investigated by 1H NMR spectroscopy. The four identified species which interconvert slowly on the NMR time scale (lifetime > 1 ms) are metMbOH (B) at alkaline pH, five coordinate metMb (N) at acidic to neutral pH, an acidic form, A, near pH approximately 4 and an extremely low pH form, D, attributed to an equilibrium unfolded species. The presence of strong distal hydrogen bonding by Arg (E10) to bound hydroxide is detected via a significant solvent isotope effect on the metMbOH (B) hyperfine shifts. Integration of the peak intensities yields pK values of 7.7 and approximately 4 for the B<-->N and N<-->A equilibria, respectively. Saturation transfer via chemical exchange is observed for B<-->N and N<-->A, where the rates for forming metMbOH (B) and the acidic form A from N are base- and acid-catalyzed, respectively, while the reverse rates are first-order. The much slower interconversion rate for N<-->B in A. limacina metMb than His(E7) containing mammalian metMb is attributed to the fact that a ligand bond is broken rather than just proton transferred and that the equilibrium involves a major rearrangement of the orientation of Arg(E10). This conclusion is supported by 1H NMR data for the sperm whale double mutant His(E7)-->Val/Thr(E10)-->Arg metMb, which exhibits a pK approximately 8.7 for the equilibrium between five-coordinate metMb (N) and metMbOH (B) with an even slower interconversion rate than in A. limacina metMb. This double mutant metMbOH (B) exhibits hydrogen bonding by Arg (E10) with coordinated hydroxide similar to that in A. limacina metMbOH. The slow but acid-catalyzed rates of conversion of A. limacina metMb (N) to the acid species A with significantly weakened bonding of the heme iron to the axial His(F8) residue is consistent with protonation of an

  20. Integration of 1H NMR and UPLC-Q-TOF/MS for a Comprehensive Urinary Metabonomics Study on a Rat Model of Depression Induced by Chronic Unpredictable Mild Stress

    PubMed Central

    Jia, Hong-mei; Feng, Yu-fei; Liu, Yue-tao; Chang, Xing; Chen, Lin; Zhang, Hong-wu; Ding, Gang; Zou, Zhong-mei

    2013-01-01

    Depression is a type of complex psychiatric disorder with long-term, recurrent bouts, and its etiology remains largely unknown. Here, an integrated approach utilizing 1H NMR and UPLC-Q-TOF/MS together was firstly used for a comprehensive urinary metabonomics study on chronic unpredictable mild stress (CUMS) treated rats. More than twenty-nine metabolic pathways were disturbed after CUMS treatment and thirty-six potential biomarkers were identified by using two complementary analytical technologies. Among the identified biomarkers, nineteen (10, 11, 16, 17, 21–25, and 27–36) were firstly reported as potential biomarkers of CUMS-induced depression. Obviously, this paper presented a comprehensive map of the metabolic pathways perturbed by CUMS and expanded on the multitude of potential biomarkers that have been previously reported in the CUMS model. Four metabolic pathways, including valine, leucine and isoleucine biosynthesis; phenylalanine, tyrosine and tryptophan biosynthesis; tryptophan metabolism; synthesis and degradation of ketone bodies had the deepest influence in the pathophysiologic process of depression. Fifteen potential biomarkers (1–2, 4–6, 15, 18, 20–23, 27, 32, 35–36) involved in the above four metabolic pathways might become the screening criteria in clinical diagnosis and predict the development of depression. Moreover, the results of Western blot analysis of aromatic L-amino acid decarboxylase (DDC) and indoleamine 2, 3-dioxygenase (IDO) in the hippocampus of CUMS-treated rats indicated that depletion of 5-HT and tryptophan, production of 5-MT and altered expression of DDC and IDO together played a key role in the initiation and progression of depression. In addition, none of the potential biomarkers were detected by NMR and LC-MS simultaneously which indicated the complementary of the two kinds of detection technologies. Therefore, the integration of 1H NMR and UPLC-Q-TOF/MS in metabonomics study provided an approach to identify the

  1. "Solvent Effects" in 1H NMR Spectroscopy.

    ERIC Educational Resources Information Center

    Cavaleiro, Jose A. S.

    1987-01-01

    Describes a simple undergraduate experiment in chemistry dealing with the "solvent effects" in nuclear magnetic resonance (NMR) spectroscopy. Stresses the importance of having students learn NMR spectroscopy as a tool in analytical chemistry. (TW)

  2. 1H NMR relaxation in urea

    NASA Astrophysics Data System (ADS)

    Taylor, R. E.; Bacher, Alfred D.; Dybowski, C.

    2007-11-01

    Proton NMR spin-lattice relaxation times T1 were measured for urea as a function of temperature. An activation energy of 46.3 ± 4.7 kJ/mol was extracted and compared with the range of 38-65 kJ/mol previously reported in the literature as measured by different magnetic resonance techniques. In addition, proton NMR spin-lattice relaxation times in the rotating frame T1 ρ were measured as a function of temperature. These measurements provide acquisition conditions for the 13C and 15N CP/MAS spectra of pure urea in the crystalline phase.

  3. A 1H NMR titration study on the binding constants for D- and L-tryptophan inclusion complexes with 6-O-α-D-glucosyl-β-cyclodextrin. Formation of 1:1 and 2:1 (host:guest) complexes

    NASA Astrophysics Data System (ADS)

    Akita, Tomoki; Matsui, Yoshihisa; Yamamoto, Tatsuyuki

    2014-02-01

    A 1H NMR titration study revealed that 6-O-α-D-glucosyl-β-cyclodextrin (G1-β-CD) forms 1:1 and 2:1 (host:guest) inclusion complexes with D- and L-tryptophan in alkaline D2O solutions (pD 11.0). The binding constants (K1's) for the 1:1 complexes of D-isomer at 298 K (59 mol-1 dm3) were virtually equal to that of L-isomer (54 mol-1 dm3). On the other hand, the K2 values for 2:1 complexes of D-isomer (42 mol-1 dm3) were larger than that of L-counterpart (12 mol-1 dm3). These facts suggest that the first CD molecule includes the indole ring moiety of tryptophan, followed by inclusion with the second CD molecule in the vicinity of chiral center, α-carbon of the guest, to result in the difference in K2's for two enantiomers. Two-dimensional NMR measurement (Rotating-frame nuclear Overhauser Effect SpectroscopY, ROESY) supported this interpretation.

  4. Thermochromism in nickel(II) complexes: thermal, IR spectroscopic, solid-state 1H NMR and single crystal X-ray analysis of diaqua-bis(2,2-dimethyl-1,3-propanediamine) nickel(II) nitrate

    NASA Astrophysics Data System (ADS)

    Koner, Subratanath; Ghosh, Ashutosh; Pariya, Chandi; Das, Debasis; Kikuchi, Hikomitsu; Okamoto, Ken-Ichi; Ikeda, Ryuichi

    1995-02-01

    The newly synthesized complex [Ni(dmtn) 2(H 2O) 2](NO 3) 2 (dmtn = 2,2-dimethyl-1,3-propanediamine) undergoes a reversible thermochromic phase transition in the range of 180-202°C ( ΔH = 10.4kJ mol -1) on heating after dehydration (dehydration temperature range 43-102°C). The complex has been characterized by X-ray crystallography at room temperature. The crystals are monoclinic, space group {C2}/{m}, a = 20.385(2), b = 6.9004(4), c = 6.9552(3) Å, β = 102.60(5)°, V = 954.8(1) Å3, Z = 2 and R = 0.046. The geometry of the nickel atom in the complex is tetragonally distorted octahedral with two H 2O molecules coordinated at the trans position. The diamine chelate rings are in the trans chair-chair conformations. The broad-line 1H NMR of partially deuterated [Ni(dmtn- d4) 2(NO 3) 2] (deuterated amine protons) indicates the onset of dynamic disorder of the diamine chelate rings at the phase transition temperature. The high temperature IR spectral measurement shows the complex retains its trans configuration after dehydration and phase transition with NO -3 ions coordinated as a monodentate ligand.

  5. Molecular structures and conformations of 1-benzenesulphonyl-2-oxo-5-alkoxypyrrolidines with anti-amnesic activity. X-ray, 1H-NMR and quantum mechanical (PM3) studies

    NASA Astrophysics Data System (ADS)

    Amato, Maria E.; Bandoli, Giuliano; Dolmella, Alessandro; Grassi, Antonio; Pappalardo, Giuseppe C.; Toja, Emilio

    1991-04-01

    The crystal and molecular structures of the nootropic agents RU-47001 ((±) 1-(4-nitrobenzenesulphonyl)-2-oxo-5-ethoxypyrrolidine) and RU-47064 ((±) 1-(4-nitrobenzenesulphonyl)-2-oxo-5-isopropyloxypyrrolidine) have been determined by X-ray analysis and their solution conformation has been investigated using 1H NMR spectroscopy. The conformations of these molecules together with those of their analogues RU-35929 ((±) 1-benzenesulphonyl-2-oxo-5-ethoxypyrrolidine), RU-47010 ((±) 1-(3-pyridinylsulphonyl)-2-oxo-5-ethoxypyrrolidine) and RU-35965 ((±) 1-benzenesulphonyl-2-oxo-5-isopropyloxypyrrolidine) have been deduced from semi-quantitative PM3 type theoretical calculations. The main feature of all compounds consists of a common envelope conformation with C (4) at the flap of the pyrrolidinone ring in the solid, that in solution changes into the analogous, but opposite, possible puckered conformational isomer. The 5-alkoxy groups were found rather flexible in solution. Theoretical preferred conformations about NS and SC bonds were in acceptable agreement with those of the solid state. The calculated torsional energetics suggested that 1- 5 do not undergo conformational interconversion.

  6. The spectroscopic (FT-IR, FT-Raman, (l3)C, (1)H NMR and UV) and NBO analyses of 4-bromo-1-(ethoxycarbonyl)piperidine-4-carboxylic acid.

    PubMed

    Vitnik, Vesna D; Vitnik, Željko J

    2015-03-01

    In this work, we will report a combined experimental and theoretical study on molecular and vibrational structure of 4-bromo-1-(ethoxycarbonyl)piperidine-4-carboxylic acid (BEPA). BEPA has been characterized by FT-IR, FT-Raman, (1)H NMR, (13)C NMR and UV spectroscopy. The FT-IR and FT-Raman spectra of BEPA were recorded in the solid phase. The optimized geometry was calculated by B3LYP and M06-2X methods using 6-311G(d,p) basis set. The FT-IR and FT-Raman spectra of BEPA were calculated at the same level and were interpreted in terms of Potential Energy Distribution (PED) analysis. The scaled theoretical wavenumber showed very good agreement with the experimental values. The (1)H and (l3)C nuclear magnetic resonance (NMR) chemical shifts of the molecule were calculated by the Gauge-Independent Atomic Orbital (GIAO) method. Stability of the molecule arising from hyperconjugative interactions and charge delocalization has been analyzed using Natural Bond Orbital (NBO) analysis. Density plots over the highest occupied molecular orbitals (HOMO) and lowest unoccupied molecular orbitals (LUMO) energy surface directly identifies the donor and acceptor atoms in the molecule. It also provides information about the charge transfer within the molecule. To obtain chemical reactivity of the molecule, the molecular electrostatic potential (MEP) surface map is plotted over the optimized geometry of the molecule. PMID:25434858

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

    PubMed Central

    Strzelecki, Dominik; Grzelak, Piotr; Podgórski, Michał; Kałużyńska, Olga; Stefańczyk, Ludomir; Kotlicka-Antczak, Magdalena; Gmitrowicz, Agnieszka

    2015-01-01

    Managing affective, negative, and cognitive symptoms remains the most difficult therapeutic problem in stable phase of schizophrenia. Efforts include administration of antidepressants. Drugs effects on brain metabolic parameters can be evaluated by means of proton nuclear magnetic resonance (1H-NMR) spectroscopy. We compared spectroscopic parameters in the left prefrontal cortex (DLPFC), the left frontal white matter (WM) and the left hippocampus and assessed the relationship between treatment and the spectroscopic parameters in both groups. We recruited 25 patients diagnosed with schizophrenia (DSM-IV-TR), with dominant negative symptoms and in stable clinical condition, who were treated with antipsychotic and antidepressive medication for minimum of three months. A group of 25 patients with schizophrenia, who were taking antipsychotic drugs but not antidepressants, was matched. We compared metabolic parameters (N-acetylaspartate (NAA), myo-inositol (mI), glutamatergic parameters (Glx), choline (Cho), and creatine (Cr)) between the two groups. All patients were also assessed with the Positive and Negative Syndrome Scale (PANSS) and the Calgary Depression Scale for Schizophrenia (CDSS). In patients receiving antidepressants we observed significantly higher NAA/Cr and NAA/Cho ratios within the DLPFC, as well as significantly higher mI/Cr within the frontal WM. Moreover, we noted significantly lower values of parameters associated with the glutamatergic transmission—Glx/Cr and Glx/Cho in the hippocampus. Doses of antipsychotic drugs in the group treated with antidepressants were also significantly lower in the patients showing similar severity of psychopathology. PMID:26501256

  8. A 1H NMR Investigation of the Interaction between Phenolic Acids Found in Mango (Manguifera indica cv Ataulfo) and Papaya (Carica papaya cv Maradol) and 1,1-diphenyl-2-picrylhydrazyl (DPPH) Free Radicals

    PubMed Central

    López-Martínez, Luis M.; Santacruz-Ortega, Hisila; Navarro, Rosa-Elena; Sotelo-Mundo, Rogerio R.; González-Aguilar, Gustavo A.

    2015-01-01

    The benefits of phenolic acids on human health are very often ascribed to their potential to counteract free radicals to provide antioxidant protection. This potential has been attributed to their acidic chemical structure, which possesses hydroxyl groups in different positions. Phenolic acids can interact between themselves and exhibit an additive, antagonistic or synergistic effect. In this paper, we used 1H NMR to analyze the interactions and mechanisms that are present in major phenolic acids found in mango (gallic, protocatechuic, chlorogenic and vanillic acids) and papaya (caffeic, ferulic and p-coumaric acids), and the DPPH radical was used to evaluate the effect of the antioxidant mixtures. The interactions were found to occur via hydrogen bonds between the -OH and -COOH groups. Moreover, the phenolic acids exhibit two types of mechanisms for the neutralization of the DPPH radical. According to the results, these two mechanisms are Hydrogen Atom Transfer (HAT) and Single Electron Transfer (SET). The ability of the phenolic acid to neutralize the DPPH radical decreases in the following order in mango: gallic > chlorogenic > protocatechuic > vanillic. Moreover, within the acids found in papaya, the order was as follows: caffeic > p-coumaric > ferulic. PMID:26559189

  9. Kinetic studies on the intramolecular acyl migration of beta-1-O-acyl glucuronides: application to the glucuronides of (R)- and (S)-ketoprofen, (R)- and (S)-hydroxy-ketoprofen metabolites, and tolmetin by 1H-NMR spectroscopy.

    PubMed

    Skordi, E; Wilson, I D; Lindon, J C; Nicholson, J K

    2005-07-01

    Conjugation of carboxylate drugs with D-glucuronic acid is of considerable interest because of the inherent reactivity of the resulting beta-1-O-acyl glucuronides. These conjugates can degrade by spontaneous hydrolysis and internal acyl migration. beta-1-O-acyl glucuronides and their acyl migration products can also react covalently with macromolecules with potential toxicological consequences. The spontaneous degradation of the diastereoisomeric beta-1-O-acyl glucuronide metabolites of the racemic drug ketoprofen, two of its ring-hydroxylated metabolites and of tolmetin beta-1-O-acyl glucuronide was investigated by (1)H-NMR spectroscopy in buffer solutions, at pH 7.4 and 37 degrees C. A plot of the logarithm of the peak integrals against time revealed first-order kinetics. Degradation rates and half-lives were calculated for each glucuronide using first-order reaction equations. Tolmetin glucuronide had the fastest degradation rate, whilst all of the ketoprofen-related glucuronides had similar degradation rates. The degradation of the diastereoisomeric glucuronides was stereoselective, with the rate for the (S)-isomer always slower compared with the (R)-isomer by approximately a factor of 2. PMID:16316930

  10. Crystal structure, FT-IR, FT-Raman, 1H NMR and computational study of ethyl 2-{[(Z)3-(4-chlorophenyl)-3-hydroxy-2-propene-1-thione] amino} acetate

    NASA Astrophysics Data System (ADS)

    Prasanth, S.; Varughese, Mary; Joseph, Nirmala; Mathew, Paulson; Manojkumar, T. K.; Sudarsanakumar, C.

    2015-02-01

    The molecular structure of a thioamide derivative ethyl 2-{[(Z)3-(4-chlorophenyl)-3-hydroxy-2-propene-1-thione] amino} acetate was determined by X-ray diffraction. The proton NMR (1H NMR), Fourier Transform Infra-Red (FT-IR) and Fourier Transform Raman (FT-Raman) spectra of the compound were recorded and analyzed. The conjugated enol form of the compound was crystallized in the monoclinic space group P21/c, with unit cell dimensions a = 12.514(2) Å, b = 5.403(5) Å, c = 21.233(3) Å, β = 94.597(4)°. The structure was solved by direct methods and refined to the R value of 0.0462. The thioamide moiety in the compound adopts the Z-conformation and the Csbnd N bond shows a high rotational barrier. The geometry in the gas phase was optimized by B3LYP and RHF quantum mechanical calculations using Gaussian 09 programme and the vibrational frequencies were calculated. The experimental and theoretical data are in good agreement.

  11. [Determination and comparative analysis of the conformation of bovine pancreatic trypsin inhibitor and trypsin inhibitors E and K from the data of two-dimensional 1H-NMR spectroscopy].

    PubMed

    Sherman, S A; Andrianov, A M

    1985-01-01

    On the basis of joint consideration of distance dependences between amide proton NH and protons C alpha H, NH, C beta H of the preceding in amino acid sequence residue from the torsion angles phi psi, chi 1, the correlation diagram of these proton-proton distances with the regions of sterically allowed conformational space (phi, psi) is presented and the method for the determination of the L-amino acid residues backbone conformations is proposed. The diagram was used for the determination of backbone conformations of bovine pancreatic trypsin inhibitor and trypsin inhibitors E and K from Dendroaspis polylepis using the data from two-dimensional 1H-NMR spectroscopy. The analysis of backbone conformations was carried out. The individual elements of these protein molecules secondary structure were characterized and their high conformational homology was shown. The inference about qualitative coincidence of three protein molecules conformation in solution, preservation of secondary structure basic elements and their similarity with bovine pancreatic trypsin inhibitor crystalline structure was made. PMID:4079926

  12. Rearrangement of the distal pocket accompanying E7 His yields Gln substitution in elephant carbonmonoxy- and oxymyoglobin: sup 1 H NMR identification of a new aromatic residue in the heme pocket

    SciTech Connect

    Yu, L.P.; La Mar, G.N. ); Mizukami, H. )

    1990-03-13

    Two-dimensional {sup 1}H NMR methods have been used to assign side-chain resonances for the residues in the distal heme pocket of elephant carbonmonoxymyoglobin (MbCO) and oxymyoglobin (MbO{sub 2}). It is shown that, while the other residues in the heme pocket are minimally perturbed, the Phe CD4 residue in elephant MbCO and MbO{sub 2} resonates considerably upfield compared to the corresponding residue in sperm whale MbCO. The new NOE connectivities to Val E11 and heme-induced ring current calculations indicate that Phe CD4 has been inserted into the distal heme pocket by reorienting the aromatic side chain and moving the CD corner closer to the heme. The C{zeta}H proton of the Phe CD4 was found to move toward the iron of the heme by {approximately}4 {angstrom} relative to the position in sperm whale MbCO, requiring minimally a 3-{angstrom} movement of the CD helical backbone. The significantly altered distal conformation in elephant myoglobin, rather than the single distal E7 substitution, forms a plausible basis for its altered functional properties of lower autoxidation rate, higher redox potential, and increased affinity for CO ligand. These results demonstrate that one-to-one interpretation of amino acid residue substitution (E7 His {yields} Gln) is oversimplified and that conformational changes of substituted proteins which are not readily predicted have to be considered for interpretation of their functional properties.

  13. A novel P450-catalyzed transformation of the 2,2,6,6-tetramethyl piperidine moiety to a 2,2-dimethyl pyrrolidine in human liver microsomes: characterization by high resolution quadrupole-time-of-flight mass spectrometry and 1H-NMR.

    PubMed

    Yin, Wenji; Doss, George A; Stearns, Ralph A; Chaudhary, Ashok G; Hop, Cornelis E; Franklin, Ronald B; Kumar, Sanjeev

    2003-02-01

    We describe herein a novel metabolic fate of the 2,2,6,6-tetramethyl-piperidine (2,2,6,6-TMPi) moiety to a ring-contracted 2,2-dimethyl pyrrolidine (2,2-DMPy) in human liver microsomal incubations. The existence of this pathway was demonstrated for three compounds (I-III) of varied structures suggesting that this may be a general biotransformation reaction for the 2,2,6,6-TMPi moiety. The 2,2-DMPy metabolites formed in incubations of the three compounds with human liver microsomes were characterized by online high performance liquid chromatography coupled to a high resolution hybrid quadrupole-time-of-flight mass spectrometer. Suggested elemental composition obtained from accurate mass measurements of the molecular ions and fragment ions of the metabolites clearly indicated the loss of a mass equivalent to C(3)H(6) from the parent 2,2,6,6-TMPi functionality. Additional accurate tandem mass spectrometry data indicated that one of the original two gem-dimethyl groups was intact in the metabolite structure. Proof of a ring-contracted 2,2-DMPy structure was obtained using (1)H-NMR experiments on a metabolite purified from liver microsomal incubations, which showed only two geminal methyl groups, instead of four in the parent compound. Two-dimensional correlation spectroscopy and decoupling experiments established aliphatic protons arranged in a pyrrolidine ring pattern. The fact that the formation of 2,2-DMPy metabolites in human liver microsomes was NADPH-dependent suggested that this novel metabolic reaction was catalyzed by the cytochrome P450 (P450) enzyme(s). Immunoinhibition studies in human liver microsomal incubations using anti-P450 monoclonal antibodies and experiments with insect cell microsomes containing individually expressed recombinant human P450 isozymes indicated that multiple P450 isozymes were capable of catalyzing this novel metabolic transformation. PMID:12527703

  14. Thermodynamic and activation parameters for dissociation of [CpCr(CO){sub 3}]{sub 2} and [Cp*Cr(CO){sub 3}]{sub 2} into paramagnetic monomers from {sup 1}H NMR shift and line width measurements

    SciTech Connect

    Woska, D.C.; Ni, Y.; Wayland, B.B.

    1999-09-06

    Substitution of pentamethyl cyclopentadienide (Cp*) for cyclopentadienide (Cp) is commonly used as an approach for increasing ligand steric requirements that can enhance dissociation of M-M bonded complexes. {sup 1}H NMR spectra for solutions prepared by dissolution of [CpCr(CO){sub 3}]{sub 2} and [Cp*Cr(CO){sub 3}]{sub 2} in toluene in the temperature range 190--390 K are interpreted in terms of thermodynamic and kinetic parameters for dissociation of the diamagnetic dimers into the paramagnetic monomers CpCr(CO){sub 3} and Cp*Cr(CO){sub 3}. There is no evidence in this temperature range for thermally populated excited states or non-Curie magnetic behavior of the monomers making a significant contribution to the NMR. An expression for the temperature dependence of the NMR chemical shift at limiting fast interchange of monomer and dimer in terms of the {Delta}H{degree} and {Delta}S{degree} for dimer dissociation is applied in determining the thermodynamic parameters for Cr-Cr bond homolysis of [CpCr(CO){sub 3}]{sub 2} ({Delta}H{sub 1}{degree} = 15.3 {+-} 0.6 kcal mol{sup {minus}1}; {Delta}S{sub 1}{degree} = 39 {+-} 2 cal K{sup {minus}1} mol{sup {minus}1}) and [Cp*Cr(CO){sub 3}]{sub 2} ({Delta}H{sub 2}{degree} = 14.2 {+-} 0.4 kcal mol{sup {minus}1}; {Delta}S{sub 2}{degree} = 47 {+-} 2 cal K{sup {minus}1}mol{sup {minus}1}). Rate constants and activation parameters have been evaluated from {sup 1}H NMR line broadening in the region of slow dimer-monomer interchange for dissociation of [CpCr(CO){sub 3}]{sub 2} ({kappa}{sub 1} (240 K) {approx} 59 s{sup {minus}1}; {Delta}H{sub 1}{double{underscore}dagger} = 17 {+-} 2 kcal mol{sup {minus}1}; {Delta}S{sub 1}{double{underscore}dagger} = 21 {+-} 6 cal K{sup {minus}1} mol{sup {minus}1}) and [Cp*Cr(CO){sub 3}]{sub 2} ({kappa}{sub 2} (240 K) {approx} 1.4 x 10{sup 4} s{sup {minus}1}; {Delta}H{sub 2}{double{underscore}dagger} = 16 {+-} 1 kcal mol{sup {minus}1}; {Delta}S{sub 2}{double{underscore}dagger} = 30 {+-} 6 cal K

  15. Solution 1H NMR investigation of the active site molecular and electronic structures of substrate-bound, cyanide-inhibited HmuO, a bacterial heme oxygenase from Corynebacterium diphtheriae.

    PubMed

    Li, Yiming; Syvitski, Ray T; Chu, Grace C; Ikeda-Saito, Masao; Mar, Gerd N La

    2003-02-28

    The molecular structure and dynamic properties of the active site environment of HmuO, a heme oxygenase (HO) from the pathogenic bacterium Corynebacterium diphtheriae, have been investigated by (1)H NMR spectroscopy using the human HO (hHO) complex as a homology model. It is demonstrated that not only the spatial contacts among residues and between residues and heme, but the magnetic axes that can be related to the direction and magnitude of the steric tilt of the FeCN unit are strongly conserved in the two HO complexes. The results indicate that very similar contributions of steric blockage of several meso positions and steric tilt of the attacking ligand are operative. A distal H-bond network that involves numerous very strong H-bonds and immobilized water molecules is identified in HmuO that is analogous to that previously identified in hHO (Li, Y., Syvitski, R. T., Auclair, K., Wilks, A., Ortiz de Montellano, P. R., and La Mar, G. N. (2002) J. Biol. Chem. 277, 33018-33031). The NMR results are completely consistent with the very recent crystal structure of the HmuO.substrate complex. The H-bond network/ordered water molecules are proposed to orient the distal water molecule near the catalytically key Asp(136) (Asp(140) in hHO) that stabilizes the hydroperoxy intermediate. The dynamic stability of this H-bond network in HmuO is significantly greater than in hHO and may account for the slower catalytic rate in bacterial HO compared with mammalian HO. PMID:12480929

  16. Studies of Structure and Phase Transition in [C(NH2)3]HgBr3 and [C(NH2)3]HgI3 by Means of Halogen NQR, 1H NMR, and Single Crystal X-Ray Diffraction

    NASA Astrophysics Data System (ADS)

    Terao, Hiromitsu; Hashimoto, Masao; Hashimoto, Shinichi; Furukawa, Yoshihiro

    2000-02-01

    The crystal structure of [C(NH2)3]HgBr3 was determined at room temperature: monoclinic, space group C2/c, Z = 4, a = 775.0(2), b = 1564.6(2), c = 772.7(2) pm, β = 109.12(2)°. In the crystal, almost planar HgBr3- ions are connected via Hg ··· Br bonds, resulting in single chains of trigonal bipyramidal HgBr5 units which run along the c direction. [C(NH2)3]HgI3 was found to be isomorphous with the bromide at room temperature. The temperature dependence of the halogen NQR frequencies (77 < 77K < ca. 380) and the DTA measurements evidenced no phase transition for the bromide, but a second-order phase transition at (251 ± 1) K (Tc1) and a first-order one at (210 ± 1) K for the iodide. The transitions at Tc2are accompanied with strong supercooling and significant superheating. The room temperature phase (RTP) and the intermediate temperature phase (ITP) of the iodide are characterized by two 127I(m=1/2↔3/2) NQR lines which are assigned to the terminal and the bridging I atoms, respectively. There exist three lines in the lowest temperature phase (LTP), indicating that the resonance line of the bridging atom splits into two. The signal intensities of the 127I(m =1/2↔3/2) NQR lines in the LTP decrease with decreasing temperature resulting in no detection below ca. 100 K. The 127I(m=1/2↔3/2) NQR frequency vs. temperature curves are continuous at Tcl, but they are unusual in the LTP. The T1vs. Tcurves of 1H NMR for the bromide and iodide are explainable by the reorientational motions of the cations about their pseudo three-fold axes. The estimated activation energies of the motions are 35.0 kJ/mol for the bromide, and 24.1, 30.1, and 23.0 kJ/mol for the RTP, FTP, and LTP of the iodide, respectively

  17. Neuropeptide signaling remodels chemosensory circuit composition in Caenorhabditis elegans

    PubMed Central

    Leinwand, Sarah G.; Chalasani, Sreekanth H.

    2013-01-01

    Neural circuits detect environmental changes and drive behavior. The routes of information flow through dense neural networks are dynamic; however, the mechanisms underlying this circuit flexibility are poorly understood. Here, we define a novel, sensory context-dependent and neuropeptide-regulated switch in the composition of a C. elegans salt sensory circuit. The primary salt detectors, ASE sensory neurons, use BLI-4 endoprotease-dependent cleavage to release the insulin-like peptide INS-6 in response to large but not small changes in external salt stimuli. Insulins, signaling through the insulin receptor DAF-2, functionally switch the AWC olfactory sensory neuron into an interneuron in the salt circuit. Animals with disrupted insulin signaling have deficits in salt attraction, suggesting that peptidergic signaling potentiates responses to high salt stimuli, which may promote ion homeostasis. Our results show that sensory context and neuropeptide signaling modify neural networks and suggest general mechanisms for generating flexible behavioral outputs by modulating neural circuit composition. PMID:24013594

  18. Neuropeptide signaling remodels chemosensory circuit composition in Caenorhabditis elegans.

    PubMed

    Leinwand, Sarah G; Chalasani, Sreekanth H

    2013-10-01

    Neural circuits detect environmental changes and drive behavior. The routes of information flow through dense neural networks are dynamic, but the mechanisms underlying this circuit flexibility are poorly understood. Here, we define a sensory context-dependent and neuropeptide-regulated switch in the composition of a C. elegans salt sensory circuit. The primary salt detectors, ASE sensory neurons, used BLI-4 endoprotease-dependent cleavage to release the insulin-like peptide INS-6 in response to large, but not small, changes in external salt stimuli. Insulins, signaling through the insulin receptor DAF-2, functionally switched the AWC olfactory sensory neuron into an interneuron in the salt circuit. Worms with disrupted insulin signaling had deficits in salt attraction, suggesting that peptidergic signaling potentiates responses to high salt stimuli, which may promote ion homeostasis. Our results indicate that sensory context and neuropeptide signaling modify neural networks and suggest general mechanisms for generating flexible behavioral outputs by modulating neural circuit composition. PMID:24013594

  19. Diverse and composite features for ECG signals processing.

    PubMed

    Ubeyli, Elif Derya

    2008-01-01

    The automated diagnostic systems employing diverse and composite features for electrocardiogram (ECG) signals were analyzed and their accuracies were determined. Because of the importance of making the right decision, classification procedures classifying the ECG signals with high accuracy were investigated. The classification accuracies of multilayer perceptron neural network (MLPNN), recurrent neural network (RNN), and mixture of experts (ME) trained on composite features and modified mixture of experts (MME) trained on diverse features were compared. The inputs of these automated diagnostic systems were composed of diverse or composite features (wavelet coefficients and power levels of the power spectral density estimates obtained by the eigenvector methods) and were chosen according to the network structures. The conclusions of this study demonstrated that the MME trained on diverse features achieved accuracy rates which were higher than that of the other automated diagnostic systems trained on composite features. PMID:18408257

  20. Unusual 1H NMR chemical shifts support (His) C(epsilon) 1...O==C H-bond: proposal for reaction-driven ring flip mechanism in serine protease catalysis.

    PubMed

    Ash, E L; Sudmeier, J L; Day, R M; Vincent, M; Torchilin, E V; Haddad, K C; Bradshaw, E M; Sanford, D G; Bachovchin, W W

    2000-09-12

    13C-selective NMR, combined with inhibitor perturbation experiments, shows that the C(epsilon)(1)H proton of the catalytic histidine in resting alpha-lytic protease and subtilisin BPN' resonates, when protonated, at 9.22 ppm and 9.18 ppm, respectively, which is outside the normal range for such protons and approximately 0.6 to 0.8 ppm further downfield than previously reported. They also show that the previous alpha-lytic protease assignments [Markley, J. L., Neves, D. E., Westler, W. M., Ibanez, I. B., Porubcan, M. A. & Baillargeon, M. W. (1980) Front. Protein Chem. 10, 31-61] were to signals from inactive or denatured protein. Simulations of linewidth vs. pH demonstrate that the true signal is more difficult to detect than corresponding signals from inactive derivatives, owing to higher imidazole pK(a) values and larger chemical shift differences between protonated and neutral forms. A compilation and analysis of available NMR data indicates that the true C(epsilon)(1)H signals from other serine proteases are similarly displaced downfield, with past assignments to more upfield signals probably in error. The downfield displacement of these proton resonances is shown to be consistent with an H-bond involving the histidine C(epsilon)(1)H as donor, confirming the original hypothesis of Derewenda et al. [Derewenda, Z. S., Derewenda, U. & Kobos, P. M. (1994) J. Mol. Biol. 241, 83-93], which was based on an analysis of literature x-ray crystal structures of serine hydrolases. The invariability of this H-bond among enzymes containing Asp-His-Ser triads indicates functional importance. Here, we propose that it enables a reaction-driven imidazole ring flip mechanism, overcoming a major dilemma inherent in all previous mechanisms, namely how these enzymes catalyze both the formation and productive breakdown of tetrahedral intermediates. PMID:10984533

  1. Unusual 1H NMR chemical shifts support (His) Cɛ1—H⋅⋅⋅O⩵C H-bond: Proposal for reaction-driven ring flip mechanism in serine protease catalysis

    PubMed Central

    Ash, Elissa L.; Sudmeier, James L.; Day, Regina M.; Vincent, Matthew; Torchilin, Ekaterina V.; Haddad, Kristin Coffman; Bradshaw, Elizabeth M.; Sanford, David G.; Bachovchin, William W.

    2000-01-01

    13C-selective NMR, combined with inhibitor perturbation experiments, shows that the Cɛ1—H proton of the catalytic histidine in resting α-lytic protease and subtilisin BPN′ resonates, when protonated, at 9.22 ppm and 9.18 ppm, respectively, which is outside the normal range for such protons and ≈0.6 to 0.8 ppm further downfield than previously reported. They also show that the previous α-lytic protease assignments [Markley, J. L., Neves, D. E., Westler, W. M., Ibanez, I. B., Porubcan, M. A. & Baillargeon, M. W. (1980) Front. Protein Chem. 10, 31–61] were to signals from inactive or denatured protein. Simulations of linewidth vs. pH demonstrate that the true signal is more difficult to detect than corresponding signals from inactive derivatives, owing to higher imidazole pKa values and larger chemical shift differences between protonated and neutral forms. A compilation and analysis of available NMR data indicates that the true Cɛ1—H signals from other serine proteases are similarly displaced downfield, with past assignments to more upfield signals probably in error. The downfield displacement of these proton resonances is shown to be consistent with an H-bond involving the histidine Cɛ1—H as donor, confirming the original hypothesis of Derewenda et al. [Derewenda, Z. S., Derewenda, U. & Kobos, P. M. (1994) J. Mol. Biol. 241, 83–93], which was based on an analysis of literature x-ray crystal structures of serine hydrolases. The invariability of this H-bond among enzymes containing Asp-His-Ser triads indicates functional importance. Here, we propose that it enables a reaction-driven imidazole ring flip mechanism, overcoming a major dilemma inherent in all previous mechanisms, namely how these enzymes catalyze both the formation and productive breakdown of tetrahedral intermediates. PMID:10984533

  2. A 1H NMR-based metabolomics approach to evaluate the geographical authenticity of herbal medicine and its application in building a model effectively assessing the mixing proportion of intentional admixtures: A case study of Panax ginseng: Metabolomics for the authenticity of herbal medicine.

    PubMed

    Nguyen, Huy Truong; Lee, Dong-Kyu; Choi, Young-Geun; Min, Jung-Eun; Yoon, Sang Jun; Yu, Yun-Hyun; Lim, Johan; Lee, Jeongmi; Kwon, Sung Won; Park, Jeong Hill

    2016-05-30

    Ginseng, the root of Panax ginseng has long been the subject of adulteration, especially regarding its origins. Here, 60 ginseng samples from Korea and China initially displayed similar genetic makeup when investigated by DNA-based technique with 23 chloroplast intergenic space regions. Hence, (1)H NMR-based metabolomics with orthogonal projections on the latent structure-discrimination analysis (OPLS-DA) were applied and successfully distinguished between samples from two countries using seven primary metabolites as discrimination markers. Furthermore, to recreate adulteration in reality, 21 mixed samples of numerous Korea/China ratios were tested with the newly built OPLS-DA model. The results showed satisfactory separation according to the proportion of mixing. Finally, a procedure for assessing mixing proportion of intentionally blended samples that achieved good predictability (adjusted R(2)=0.8343) was constructed, thus verifying its promising application to quality control of herbal foods by pointing out the possible mixing ratio of falsified samples. PMID:26942336

  3. 1H NMR Study of the Enantioselective Binding of λ- and Δ-[Ru(bpy)2(m-bpy-GHK)]Cl2 to the Deoxynucleotide Duplex d(5'-C1G2C3G4A5A6T7T8C9G10C11G12-3')2

    PubMed Central

    Myari, A.; Garoufis, A.

    2005-01-01

    The interaction of the diastereomeric complexes Λ- and Δ - [Ru(bpy)2(m - GHK)]Cl2, (GHK = glycine-histidine-lysine) to the deoxynucleotide duplex d(5'-CGCGAATTCGCG-3')2 was studied by means of 1H NMR spectroscopy. The diastereomers interact with the oligonucleotide duplex differently. The Δ - [Ru(bpy)2 (m - GHK)]Cl2 is characterized by major groove binding close to the central part of the oligonucleotide, with both the peptide and the bipyridine ligand of the complex involved in the binding. The λ - [Ru(bpy)2 (m - bpy - GHK)]C2 binds loosely, approaching the helix from the minor groove. The NMR analysis shows that the peptide (GHK) binding has a determinative role in the interactions of both diastereomers with the oligonucleotide. PMID:18365093

  4. Synthesis and x-ray structural characterization of binuclear iridium(I) and rhodium(I) hydroxypyridinate complexes. 1. Complete assignment of the /sup 1/H NMR spectra by two-dimensional and NOE techniques. The nature of inside and outside /sup 1/H chemical shift differences

    SciTech Connect

    Rodman, G.S.; Mann, K.R.

    1988-09-21

    Six new d/sup 8/-d/sup 8/ complexes, (Ir(COD)(..mu..-hp))/sub 2/, (Ir(COD)(..mu..-mhp))/sub 2/, (Ir(COD)(..mu..-chp))/sub 2/, (Ir(COD)(..mu..-2hq))/sub 2/, (Rh(COD)(..mu..-hp))/sub 2/, and (Rh(COD)(..mu..-mhp))/sub 2/ (hp = 2-hydroxyphridinate, mhp = 6-methyl-2-hydroxypyridinate, chp = 6-chloro-2-hydroxypyridinate, 2hq = 2-hydroxyquinolate, COD = 1,5-cyclooctadiene), were synthesized and characterized by /sup 1/H NMR, /sup 13/C NMR, and IR spectroscopy and FAB mass spectrometry. X-ray crystallographic analyses of the isostructural (M(COD)(..mu..-mhp))/sub 2/ (M = Ir and Rh) complexes confirmed the binuclear nature of the complexes. The complete assignment of the /sup 1/H NMR spectrum of (Ir(COD)(..mu..-hp))/sub 2/ (and by analogy, the spectra of the other five complexes) was carried out with selective decoupling, nuclear Overhauser effect (NOE), and two-dimensional NMR techniques. The NOE observed between hp proton H5 and COD proton H15 allowed the precise assignment of all 12 COD resonances. Olefinic proton H12 (trans to N and outside) resonates downfield of olefinic proton H11 (trans to N and inside). Olefininc proton H15 (trans to O and outside) resonates upfield of olefinic proton H16 (trans to O and inside). The endo methylene protons resonate upfield of the exo methylene protons. The inside/outside chemical shift differences observed for these compounds are ascribed to steric and magnetic anisotropy effects. The crystallographic data are presented. The molecular structure of the complexes is discussed in detail. 39 references, 5 figures, 9 tables.

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

    PubMed

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

    1984-07-25

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

  6. (1)H NMR assignment corrections and (1)H, (13)C, (15)N NMR coordination shifts structural correlations in Fe(II), Ru(II) and Os(II) cationic complexes with 2,2'-bipyridine and 1,10-phenanthroline.

    PubMed

    Pazderski, Leszek; Pawlak, Tomasz; Sitkowski, Jerzy; Kozerski, Lech; Szłyk, Edward

    2010-06-01

    (1)H, (13)C and (15)N NMR studies of iron(II), ruthenium(II) and osmium(II) tris-chelated cationic complexes with 2,2'-bipyridine and 1,10-phenanthroline of the general formula [M(LL)(3)](2+) (M = Fe, Ru, Os; LL = bpy, phen) were performed. Inconsistent literature (1)H signal assignments were corrected. Significant shielding of nitrogen-adjacent protons [H(6) in bpy, H(2) in phen] and metal-bonded nitrogens was observed, being enhanced in the series Ru(II) --> Os(II) --> Fe(II) for (1)H, Fe(II) --> Ru(II) --> Os(II) for (15)N and bpy --> phen for both nuclei. The carbons are deshielded, the effect increasing in the order Ru(II) --> Os(II) --> Fe(II). PMID:20474023

  7. A study on the AMACR catalysed elimination reaction and its application to inhibitor testing† †Electronic supplementary information (ESI) available: 1H NMR spectra of synthesised compounds; details of X-ray crystal structure determination of compound 35; original data for Table 1; plots of fluorescence resulting from reaction of sensors 33 and 34 with fluoride solutions. CCDC 1408401. For ESI and crystallographic data in CIF or other electronic format see DOI: 10.1039/c5ob01541c Click here for additional data file. Click here for additional data file.

    PubMed Central

    Yevglevskis, Maksims; Lee, Guat L.; Sun, Jenny; Zhou, Shiyi; Sun, Xiaolong; Kociok-Köhn, Gabriele; James, Tony D.; Woodman, Timothy J.

    2016-01-01

    α-Methylacyl-CoA racemase (AMACR; P504S) catalyses a key step in the degradation of branched-chain fatty acids and is important for the pharmacological activation of Ibuprofen and related drugs. Levels of AMACR are increased in prostate and other cancers, and it is a drug target. Development of AMACR as a drug target is hampered by lack of a convenient assay. AMACR irreversibly catalyses the elimination of HF from 3-fluoro-2-methylacyl-CoA substrates, and this reaction was investigated for use as an assay. Several known inhibitors and alternative substrates reduced conversion of 3-fluoro-2-methyldecanoyl-CoA by AMACR, as determined by 1H NMR. The greatest reduction of activity was observed with known potent inhibitors. A series of novel acyl-CoA esters with aromatic side chains were synthesised for testing as chromophoric substrates. These acyl-CoA esters were converted to unsaturated products by AMACR, but their use was limited by non-enzymatic elimination. Fluoride sensors were also investigated as a method of quantifying released fluoride and thus AMACR activity. These sensors generally suffered from high background signal and lacked reproducibility under the assay conditions. In summary, the elimination reaction can be used to characterise inhibitors, but it was not possible to develop a convenient colorimetric or fluorescent assay using 3-fluoro-2-methylacyl-CoA substrates. PMID:26537174

  8. p53 attenuates AKT signaling by modulating membrane phospholipid composition

    PubMed Central

    Rueda-Rincon, Natalia; Bloch, Katarzyna; Derua, Rita; Vyas, Rajesh; Harms, Amy; Hankemeier, Thomas; Khan, Niamat Ali; Dehairs, Jonas; Bagadi, Muralidhararao; Binda, Maria Mercedes; Waelkens, Etienne; Marine, Jean-Christophe; Swinnen, Johannes V.

    2015-01-01

    The p53 tumor suppressor is the central component of a complex network of signaling pathways that protect organisms against the propagation of cells carrying oncogenic mutations. Here we report a previously unrecognized role of p53 in membrane phospholipids composition. By repressing the expression of stearoyl-CoA desaturase 1, SCD, the enzyme that converts saturated to mono-unsaturated fatty acids, p53 causes a shift in the content of phospholipids with mono-unsaturated acyl chains towards more saturated phospholipid species, particularly of the phosphatidylinositol headgroup class. This shift affects levels of phosphatidylinositol phosphates, attenuates the oncogenic AKT pathway, and contributes to the p53-mediated control of cell survival. These findings expand the p53 network to phospholipid metabolism and uncover a new molecular pathway connecting p53 to AKT signaling. PMID:26061814

  9. Structural changes of lipoprotein lipids by 1H NMR

    NASA Astrophysics Data System (ADS)

    Ala-Korpela, M.; Oja, J.; Lounila, J.; Jokisaari, J.; Savolainen, M. J.; Kesäniemi, Y. A.

    1995-08-01

    A new procedure for detecting structural changes of lipoprotein lipids is introduced and applied to study native low (LDL) and high density lipoprotein (HDL) particles. The method involves lineshape fitting analyses of specific resonances in proton nuclear magnetic resonance spectra together with numerical derivation of the obtained intensity curves with respect to temperature. In addition to the well-known phase transition of the LDL core cholesterol esters, a novel structural change was revealed in the phospholipid monolayer of both native LDL and HDL particles. The attributes of this phenomenon are discussed.

  10. Single-shot diffusion trace (1)H NMR spectroscopy.

    PubMed

    de Graaf, R A; Braun, K P; Nicolay, K

    2001-05-01

    Ignoring diffusion anisotropy can severely hamper the quantitative determination of water and metabolite diffusion in complex tissues. The measurement of the trace of the diffusion tensor provides unambiguous and rotationally invariant ADC values, but usually requires three separate experiments. A single-shot technique developed earlier, originally designed for diffusion trace MR imaging (Mori and van Zijl, Magn Reson Med 1995;33:41-52), was improved and adapted for diffusion trace MR spectroscopy. A double spin-echo pulse sequence was incorporated with four pairs of bipolar gradients with specific predetermined relative signs in each of the three orthogonal directions. The combination of gradient directions leads to cancellation of all off-diagonal tensor elements while constructively adding the diagonal elements. Furthermore, the pulse scheme provides complete compensation for cross-terms between static magnetic field gradients and the applied diffusion gradients, while simultaneously avoiding cross-terms with localization gradients. The sequence was tested at 4.7 T in vivo on rat brain for MRI and on rat skeletal muscle and brain for MRS. It is shown that the average ADC as determined from the measurement of the ADCs in the three orthogonal directions is in close agreement with the ADC obtained along the trace of the diffusion tensor in a single acquisition, for both water and metabolite diffusion. The large differences in water and metabolite diffusion coefficients as measured in the individual orthogonal directions illustrate the need for diffusion trace measurements when accurate and rotationally invariant diffusion quantitation is required. The pulse scheme presented here may be applied for such purposes in MRS and MRI studies. PMID:11323799

  11. Diffusional Properties of Methanogenic Granular Sludge: 1H NMR Characterization

    PubMed Central

    Lens, Piet N. L.; Gastesi, Rakel; Vergeldt, Frank; van Aelst, Adriaan C.; Pisabarro, Antonio G.; Van As, Henk

    2003-01-01

    The diffusive properties of anaerobic methanogenic and sulfidogenic aggregates present in wastewater treatment bioreactors were studied using diffusion analysis by relaxation time-separated pulsed-field gradient nuclear magnetic resonance (NMR) spectroscopy and NMR imaging. NMR spectroscopy measurements were performed at 22°C with 10 ml of granular sludge at a magnetic field strength of 0.5 T (20 MHz resonance frequency for protons). Self-diffusion coefficients of H2O in the investigated series of mesophilic aggregates were found to be 51 to 78% lower than the self-diffusion coefficient of free water. Interestingly, self-diffusion coefficients of H2O were independent of the aggregate size for the size fractions investigated. Diffusional transport occurred faster in aggregates growing under nutrient-rich conditions (e.g., the bottom of a reactor) or at high (55°C) temperatures than in aggregates cultivated in nutrient-poor conditions or at low (10°C) temperatures. Exposure of aggregates to 2.5% glutaraldehyde or heat (70 or 90°C for 30 min) modified the diffusional transport up to 20%. In contrast, deactivation of aggregates by HgCl2 did not affect the H2O self-diffusion coefficient in aggregates. Analysis of NMR images of a single aggregate shows that methanogenic aggregates possess a spin-spin relaxation time and self-diffusion coefficient distribution, which are due to both physical (porosity) and chemical (metal sulfide precipitates) factors. PMID:14602624

  12. Preliminary 1H NMR study on archaeological waterlogged wood.

    PubMed

    Maccotta, Antonella; Fantazzini, Paola; Garavaglia, Carla; Donato, Ines D; Perzia, Patrizia; Brai, Maria; Morreale, Filippa

    2005-01-01

    Magnetic Resonance Relaxation (MRR) and Magnetic Resonance Imaging (MRI) are powerful tools to obtain detailed information on the pore space structure that one is unlikely to obtain in other ways. These techniques are particularly suitable for Cultural Heritage materials, because they use water 1H nuclei as a probe. Interaction with water is one of the main causes of deterioration of materials. Porous structure in wood, for example, favours the penetration of water, which can carry polluting substances and promote mould growth. A particular case is waterlogged wood from underwater discoveries and moist sites; in fact, these finds are very fragile because of chemical, physical and biological decay from the long contact with the water. When wood artefacts are brought to the surface and directly dried in air, there is the collapse of the cellular structures, and wood loses its original form and dimensions and cannot be used for study and museum exhibits. In this work we have undertaken the study of some wood finds coming from Ercolano's harbour by MRR and MRI under different conditions, and we have obtained a characterization of pore space in wood and images of the spatial distribution of the confined water in the wood. PMID:16485652

  13. Cross Polarization for 1H NMR Image Contrast in Solids

    NASA Astrophysics Data System (ADS)

    Nakai, Toshihito; Fukunaga, Yasuhiro; Nonaka, Masayuki; Matsui, Shigeru; Inouye, Tamon

    1998-09-01

    A novel1H imaging method for solids, yielding images reflecting1H-13C dipolar interactions through cross relaxation timeTIS, is presented. Phase-alternating multiple-contact cross polarization (PAMC CP) was incorporated into the magic-echo frequency-encoding imaging scheme; the PAMC CP sequence may partly but efficiently destroy the initial1H magnetization depending on theTISvalues. A theory describing the effects of the PAMC CP sequence was developed, which was used for the assessment of the sequence as well as the analysis for the experimental results. It was demonstrated that theTIS-weighted1H image and theTISmapping for a phantom, constituted of adamantane and ferrocene, can distinguish these compounds clearly.

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

    ERIC Educational Resources Information Center

    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…

  15. Conformation of the nootropic agents 1-(4-methoxybenzoyl)-5-oxo-2-pyrrolidinepropanoic acid (CI-933) and 4-hydroxymethyl-1-benzyl-pyrrolidin-2-one (WEB-1868): X-ray crystal structures, theoretical MO calculations (AM-1) and 600 MHZ 1H NMR spectra

    NASA Astrophysics Data System (ADS)

    Amato, Maria E.; Bandoli, Giuliano; Djedaïni, Florence; Dolmella, Alessandro; Grassi, Antonio; Pappalardo, Giuseppe C.

    1990-05-01

    The crystal and molecular structures of the cognition activators 1-(4-methoxybenzoyl)-5-oxo-2-pyrrolidinepropanoic acid (CI-933) ( 1) and 4-hydroxymethyl-1-benzyl-pyrrolidin-2-one (WEB-1868) ( 2) have been determined by X-ray analysis. The conformations of the isolated molecules 1 and 2 have been deduced from AM1-type theoretical calculations. Whilst in 1 there are no hydrogen bonds, in 2 stabilization of the crystal occurs through effective inter- and intramolecular ? bonds. The five-membered ring in both 1 and 2 adopts an envelope conformation in the solid with C(3) at the flap displaced from the C(1), C(2), C(4), N(5) mean plane. Bond distances and angles are normal and comparable with previously known similar structures. In the crystal, the torsion angles C(1)-N(5)-C(6)-C(7) and N(5)-C(6)-C(7)-C(8) in 1 are 43.1° and 44.8°, respectively; the same torsion angles in 2 are -101° and 42°, respectively. Results of theoretical calculations correlate well with the conformation of 1 in the solid, whilst in the case of 2 these indicate that the conformation in the crystal should not be retained by the isolated molecule. The complete analysis of the very high field (600 MHz) 1H NMR spectra of both compounds in CDCl 3, gives results well in line with the above established conformational features.

  16. Compositional differences among Chinese soy sauce types studied by (13)C NMR spectroscopy coupled with multivariate statistical analysis.

    PubMed

    Kamal, Ghulam Mustafa; Wang, Xiaohua; Bin Yuan; Wang, Jie; Sun, Peng; Zhang, Xu; Liu, Maili

    2016-09-01

    Soy sauce a well known seasoning all over the world, especially in Asia, is available in global market in a wide range of types based on its purpose and the processing methods. Its composition varies with respect to the fermentation processes and addition of additives, preservatives and flavor enhancers. A comprehensive (1)H NMR based study regarding the metabonomic variations of soy sauce to differentiate among different types of soy sauce available on the global market has been limited due to the complexity of the mixture. In present study, (13)C NMR spectroscopy coupled with multivariate statistical data analysis like principle component analysis (PCA), and orthogonal partial least square-discriminant analysis (OPLS-DA) was applied to investigate metabonomic variations among different types of soy sauce, namely super light, super dark, red cooking and mushroom soy sauce. The main additives in soy sauce like glutamate, sucrose and glucose were easily distinguished and quantified using (13)C NMR spectroscopy which were otherwise difficult to be assigned and quantified due to serious signal overlaps in (1)H NMR spectra. The significantly higher concentration of sucrose in dark, red cooking and mushroom flavored soy sauce can directly be linked to the addition of caramel in soy sauce. Similarly, significantly higher level of glutamate in super light as compared to super dark and mushroom flavored soy sauce may come from the addition of monosodium glutamate. The study highlights the potentiality of (13)C NMR based metabonomics coupled with multivariate statistical data analysis in differentiating between the types of soy sauce on the basis of level of additives, raw materials and fermentation procedures. PMID:27343582

  17. Composition for detection of cell density signal molecule

    DOEpatents

    Schwarz, Richard I.

    2001-01-01

    Disclosed herein is a novel proteinaceous cell density signal molecule (CDS), which is secreted by fibroblastic cells in culture, preferably tendon cells, and which provides a means by which the cells self-regulate their proliferation and the expression of differentiated function. CDS, and the antibodies which recognize them, are important for the development of diagnostics and treatments for injuries and diseases involving connective tissues, particularly tendon. Also disclosed are methods of production and use.

  18. Comparison of spread spectrum and pulse signal excitation for split spectrum techniques composite imaging

    NASA Astrophysics Data System (ADS)

    Svilainis, L.; Kitov, S.; Rodríguez, A.; Vergara, L.; Dumbrava, V.; Chaziachmetovas, A.

    2012-12-01

    Ultrasonic imaging of composites was investigated. Glass and carbon fiber reinforced plastic produced by resin transfer molding and prepreg forming were analyzed. In some of the samples air bubbles were trapped during RTM (resin transfer molding) process and interlayer gaps were present in prepreg technology samples. One of the most expected techniques to apply in such case is the Split Spectrum processing. On the other hand such signals require specific processing to reliably reconstruct the temporal position of the defect reflection. Correlation processing can be used for signal compression or Wiener filtering can be applied for spectral content equalisation. Pulse signals are simple to generate, but lack the possibility to alter the signal's spectrum shape. Spread spectrum signals offer a powerful tool for signal energy over frequency band increase and resolution enhancement. CW (continuous wave) burst has high energy but lacks the bandwidth needed for SSP (spread spectrum processing). The aim of the investigation was to compare the performance of the above signals in case of composite imaging, when various Split Spectrum Processing techniques are used with preceding Wiener processing for spectral content compensation. Resulting composite signals and images obtained are presented. Structural noise removal performance was evaluated as Receiver Operating Characteristics (ROC).

  19. Microscale determination of the spectral characteristics and carbon-isotopic compositions of porphyrins

    NASA Technical Reports Server (NTRS)

    Popp, B. N.; Hayes, J. M.; Boreham, C. J.

    1993-01-01

    Molar extinction coefficients for band III of Ni porphyrins are calculated from results of spectrophotometric and manometric analyses of individual etioporphyrins, DPEP, cyclic, and diDPEP porphyrins known to initially be pure from mass spectrometry, 1H NMR, and analytical HPLC studies. A method for determining carbon-isotopic compositions and purity of micromolar quantities of individual porphyrins using combined spectrophotometric and manometric techniques is presented.

  20. A Approach for the Separation of Voices in Composite Musical Signals.

    NASA Astrophysics Data System (ADS)

    Maher, Robert Crawford

    The simultaneous presentation of several sound sources in a performance setting is fundamental to most music. Ensemble musical signals consist of superpositions of multiple distinct sonic events which may or may not be synchronized in time, frequency, and/or amplitude. Once the distinct events are combined and recorded in a storage medium, e.g., a digital recording, the composite signal is often unsatisfactory in some way: the recording might suffer from poor ensemble balance, performance errors, or corruption from undesired background audience noises (sneezing, talking, etc.). Although it often might be helpful to process the constituent signals independently, separating the composite signal into its parts is a nontrivial task. The research reported here considers particular aspects of the separation problem: analysis, identification, tracking, and resynthesis of a specified voice from a digital recording of a musical duet setting. Analysis is accomplished out of real-time using a quasi-harmonic, sinusoidal representation of the constituent signals, based on short-time Fourier transform (STFT) methods. The procedure is evaluated via resynthesis of a "desired" signal from the composite analysis and tracking data. Other applications include signal restoration, digital editing and splicing, musique concrete, noise reduction, and time-scale compression/expansion. This material is based upon work supported, in part, under a National Science Foundation Graduate Fellowship. Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author and do not necessarily reflect the views of the National Science Foundation.

  1. Sensor-Based Vibration Signal Feature Extraction Using an Improved Composite Dictionary Matching Pursuit Algorithm

    PubMed Central

    Cui, Lingli; Wu, Na; Wang, Wenjing; Kang, Chenhui

    2014-01-01

    This paper presents a new method for a composite dictionary matching pursuit algorithm, which is applied to vibration sensor signal feature extraction and fault diagnosis of a gearbox. Three advantages are highlighted in the new method. First, the composite dictionary in the algorithm has been changed from multi-atom matching to single-atom matching. Compared to non-composite dictionary single-atom matching, the original composite dictionary multi-atom matching pursuit (CD-MaMP) algorithm can achieve noise reduction in the reconstruction stage, but it cannot dramatically reduce the computational cost and improve the efficiency in the decomposition stage. Therefore, the optimized composite dictionary single-atom matching algorithm (CD-SaMP) is proposed. Second, the termination condition of iteration based on the attenuation coefficient is put forward to improve the sparsity and efficiency of the algorithm, which adjusts the parameters of the termination condition constantly in the process of decomposition to avoid noise. Third, composite dictionaries are enriched with the modulation dictionary, which is one of the important structural characteristics of gear fault signals. Meanwhile, the termination condition of iteration settings, sub-feature dictionary selections and operation efficiency between CD-MaMP and CD-SaMP are discussed, aiming at gear simulation vibration signals with noise. The simulation sensor-based vibration signal results show that the termination condition of iteration based on the attenuation coefficient enhances decomposition sparsity greatly and achieves a good effect of noise reduction. Furthermore, the modulation dictionary achieves a better matching effect compared to the Fourier dictionary, and CD-SaMP has a great advantage of sparsity and efficiency compared with the CD-MaMP. The sensor-based vibration signals measured from practical engineering gearbox analyses have further shown that the CD-SaMP decomposition and reconstruction algorithm

  2. Sensor-based vibration signal feature extraction using an improved composite dictionary matching pursuit algorithm.

    PubMed

    Cui, Lingli; Wu, Na; Wang, Wenjing; Kang, Chenhui

    2014-01-01

    This paper presents a new method for a composite dictionary matching pursuit algorithm, which is applied to vibration sensor signal feature extraction and fault diagnosis of a gearbox. Three advantages are highlighted in the new method. First, the composite dictionary in the algorithm has been changed from multi-atom matching to single-atom matching. Compared to non-composite dictionary single-atom matching, the original composite dictionary multi-atom matching pursuit (CD-MaMP) algorithm can achieve noise reduction in the reconstruction stage, but it cannot dramatically reduce the computational cost and improve the efficiency in the decomposition stage. Therefore, the optimized composite dictionary single-atom matching algorithm (CD-SaMP) is proposed. Second, the termination condition of iteration based on the attenuation coefficient is put forward to improve the sparsity and efficiency of the algorithm, which adjusts the parameters of the termination condition constantly in the process of decomposition to avoid noise. Third, composite dictionaries are enriched with the modulation dictionary, which is one of the important structural characteristics of gear fault signals. Meanwhile, the termination condition of iteration settings, sub-feature dictionary selections and operation efficiency between CD-MaMP and CD-SaMP are discussed, aiming at gear simulation vibration signals with noise. The simulation sensor-based vibration signal results show that the termination condition of iteration based on the attenuation coefficient enhances decomposition sparsity greatly and achieves a good effect of noise reduction. Furthermore, the modulation dictionary achieves a better matching effect compared to the Fourier dictionary, and CD-SaMP has a great advantage of sparsity and efficiency compared with the CD-MaMP. The sensor-based vibration signals measured from practical engineering gearbox analyses have further shown that the CD-SaMP decomposition and reconstruction algorithm

  3. Spectral composition of a measuring signal during measurements of vibration rates of a moving body

    NASA Technical Reports Server (NTRS)

    Daynauskas, I. A. I.; Slepov, N. N.

    1973-01-01

    Cybernetics diagnostics of machines and mechanisms using the spectral approach is discussed. The problem of establishing the accuracy of determination of the spectral composition is investigated. In systems with rectilinear or rotary movement, the vibrations appear in the form of movement rate vibrations, which are equivalent to frequency modulation of the signal, in proportion to the mean movement rate of the body. The case of a harmonic signal which reproduces and analyzes the characteristics of the frequency modulated signal is discussed. Mathematical models are developed to show the relationships of the parameters.

  4. Enhancement of Phased Array Ultrasonic Signal in Composite Materials using TMST Algorithm

    NASA Astrophysics Data System (ADS)

    Abdessalem, Benammar; Redouane, Drai; Ahmed, Kechida; Lyamine, Dris; Farid, Chibane

    In this paper, we apply a new technique for the ultrasonic phased array signal enhancement. It is based on the threshold modified S-transform (TMST). The signal processing algorithms generally give very satisfactory results on synthetic signals verifying the implicit or explicit hypotheses on which they are constructed. The obtained performances on the real signals can be however different radically. Time-frequency analysis methods are mainly used to improve the defects detection resolution. Significant performance enhancement is confirmed when the proposed approach is tested with the simulation of the B-scan signals contain a closer delamination to the front face. The experimental results show that the TMST Algorithm can enhance the quality of image provided by composite materials contained delamination defect.

  5. Mix it and fix it: functions of composite olfactory signals in ring-tailed lemurs

    PubMed Central

    Greene, Lydia K.; Grogan, Kathleen E.; Smyth, Kendra N.; Adams, Christine A.; Klager, Skylar A.; Drea, Christine M.

    2016-01-01

    Animals communicating via scent often deposit composite signals that incorporate odorants from multiple sources; however, the function of mixing chemical signals remains understudied. We tested both a ‘multiple-messages’ and a ‘fixative’ hypothesis of composite olfactory signalling, which, respectively, posit that mixing scents functions to increase information content or prolong signal longevity. Our subjects—adult, male ring-tailed lemurs (Lemur catta)—have a complex scent-marking repertoire, involving volatile antebrachial (A) secretions, deposited pure or after being mixed with a squalene-rich paste exuded from brachial (B) glands. Using behavioural bioassays, we examined recipient responses to odorants collected from conspecific strangers. We concurrently presented pure A, pure B and mixed A + B secretions, in fresh or decayed conditions. Lemurs preferentially responded to mixed over pure secretions, their interest increasing and shifting over time, from sniffing and countermarking fresh mixtures, to licking and countermarking decayed mixtures. Substituting synthetic squalene (S)—a well-known fixative—for B secretions did not replicate prior results: B secretions, which contain additional chemicals that probably encode salient information, were preferred over pure S. Whereas support for the ‘multiple-messages’ hypothesis underscores the unique contribution from each of an animal's various secretions, support for the ‘fixative’ hypothesis highlights the synergistic benefits of composite signals. PMID:27152222

  6. Mix it and fix it: functions of composite olfactory signals in ring-tailed lemurs.

    PubMed

    Greene, Lydia K; Grogan, Kathleen E; Smyth, Kendra N; Adams, Christine A; Klager, Skylar A; Drea, Christine M

    2016-04-01

    Animals communicating via scent often deposit composite signals that incorporate odorants from multiple sources; however, the function of mixing chemical signals remains understudied. We tested both a 'multiple-messages' and a 'fixative' hypothesis of composite olfactory signalling, which, respectively, posit that mixing scents functions to increase information content or prolong signal longevity. Our subjects-adult, male ring-tailed lemurs (Lemur catta)-have a complex scent-marking repertoire, involving volatile antebrachial (A) secretions, deposited pure or after being mixed with a squalene-rich paste exuded from brachial (B) glands. Using behavioural bioassays, we examined recipient responses to odorants collected from conspecific strangers. We concurrently presented pure A, pure B and mixed A + B secretions, in fresh or decayed conditions. Lemurs preferentially responded to mixed over pure secretions, their interest increasing and shifting over time, from sniffing and countermarking fresh mixtures, to licking and countermarking decayed mixtures. Substituting synthetic squalene (S)-a well-known fixative-for B secretions did not replicate prior results: B secretions, which contain additional chemicals that probably encode salient information, were preferred over pure S. Whereas support for the 'multiple-messages' hypothesis underscores the unique contribution from each of an animal's various secretions, support for the 'fixative' hypothesis highlights the synergistic benefits of composite signals. PMID:27152222

  7. Signal Processing Variables for Optimization of Flaw Detection in Composites Using Ultrasonic Guided Wave Scanning

    NASA Technical Reports Server (NTRS)

    Roth, Don J.; Cosgriff, Laura M.; Martin, Richard E.; Teemer, LeTarrie

    2004-01-01

    This study analyzes the effect of signal processing variables on the ability of the ultrasonic guided wave scan method at NASA Glenn Research Center to distinguish various flaw conditions in ceramic matrix composites samples. In the ultrasonic guided wave scan method, several time- and frequency-domain parameters are calculated from the ultrasonic guided wave signal at each scan location to form images. The parameters include power spectral density, centroid mean time, total energy (zeroth moment), centroid frequency, and ultrasonic decay rate. A number of signal processing variables are available to the user when calculating these parameters. These signal processing variables include 1) the time portion of the time-domain waveform processed, 2) integration type for the properties requiring integrations, 3) bounded versus unbounded integrations, 4) power spectral density window type, 5) and the number of time segments chosen if using the short-time fourier transform to calculate ultrasonic decay rate. Flaw conditions examined included delamination, cracking, and density variation.

  8. New delay-integration method for resolving individual components of a pair of composite signals

    SciTech Connect

    Petrek, Derek J.; Bhushan, Bharat

    2007-08-15

    Many scientific measurements are actually a composite of two or more indirectly measured values. A distance measurement, for example, is actually a measurement of the true distance and some amount of error added together. A new method for decomposing a pair of such composite signals into their individual components in certain situations is described. The method utilizes a delay time difference between the components in each of the two composite signals to provide information necessary to reconstruct the individual components. This decomposition would allow for the possible removal of one of the components, such as in the case of unwanted noise. The method is able to distinguish between two signals with similar frequencies and amplitudes, making it a viable solution in situations where simple low- or high-pass filtering would remove needed signal information. Three successful applications of the method are described, including measurement of lateral tape motion (LTM) in a magnetic data storage tape drive and removal of additive noise from both an electrical and a mechanical system.

  9. Modulation of FAK and Src adhesion signaling occurs independently of adhesion complex composition.

    PubMed

    Horton, Edward R; Humphries, Jonathan D; Stutchbury, Ben; Jacquemet, Guillaume; Ballestrem, Christoph; Barry, Simon T; Humphries, Martin J

    2016-02-01

    Integrin adhesion complexes (IACs) form mechanochemical connections between the extracellular matrix and actin cytoskeleton and mediate phenotypic responses via posttranslational modifications. Here, we investigate the modularity and robustness of the IAC network to pharmacological perturbation of the key IAC signaling components focal adhesion kinase (FAK) and Src. FAK inhibition using AZ13256675 blocked FAK(Y397) phosphorylation but did not alter IAC composition, as reported by mass spectrometry. IAC composition was also insensitive to Src inhibition using AZD0530 alone or in combination with FAK inhibition. In contrast, kinase inhibition substantially reduced phosphorylation within IACs, cell migration and proliferation. Furthermore using fluorescence recovery after photobleaching, we found that FAK inhibition increased the exchange rate of a phosphotyrosine (pY) reporter (dSH2) at IACs. These data demonstrate that kinase-dependent signal propagation through IACs is independent of gross changes in IAC composition. Together, these findings demonstrate a general separation between the composition of IACs and their ability to relay pY-dependent signals. PMID:26833789

  10. Defect Detection of Fiberglass Composite Laminates (FGCL) with Ultrasonic A-Scan Signal Measurement

    NASA Astrophysics Data System (ADS)

    Mahmod, M. F.; Abu Bakar, Elmi; Othman, A. R.

    2016-02-01

    Fiberglass composite laminates are widely used in many industries, due to its advantages of high specific strength and high specific modulus. Invisible defect such as delamination and inclusion may cause composite structural failure. Therefore, several research on ultrasonic testing for composite material defect detection have been done for the past few years. However, improper parameter setup may lead to significant error to determine the behavior of defects. In this paper, the intensive study on defect detection with ultrasonic single crystal immersion transducer has been conducted. In general, the defects detection thru acquired signal is determine the behavior of defects through the certain ultrasonic parameter setup such as sound velocity, pulse width, gain, sampling rate and transducer distance with specimen surface. Furthermore, an A-scan signal interpretation for FGCL defect detection is demonstrated and illustrated. This research is focusing on for FGCL with maximum thickness up to 10 mm in ambient temperature. The result shows an appropriate ultrasonic parameter will result better signal interpretation analysis.

  11. Wave mode extraction from multimodal wave signals in an orthotropic composite plate.

    PubMed

    Ratassepp, M; Fan, Z; Lasn, K

    2016-09-01

    In this paper the post-processing procedure based on the mode orthogonality is applied to extract individual waveforms at a composite plate edge from multimodal signals. To obtain the amplitudes of individual modes, numerically predicted modal through-thickness stress and displacement field values are used in the orthogonality relation. The performance of the mode extraction technique is evaluated by processing signals obtained from Finite Element (FE) modeling and experimental measurements. The propagation of the overlapping wave packets of Lamb modes S0 and A0 is considered along the fiber direction and perpendicular to that direction. The required experimental two-dimensional displacement components at the plate edge are measured by 3D Scanning Laser Doppler Vibrometer (3D SLDV). It is demonstrated that S0 mode can be extracted very well from the signal but A0 mode with slightly poorer accordance with the original waveforms and numerical predictions. PMID:27403641

  12. Magnetodielectric effect and electric-induced magnetic permeability in magnetoelectric laminate composite under low inspiring signal

    NASA Astrophysics Data System (ADS)

    Zhou, Jian-Ping; Zhang, Yu-Xiang; Zhang, Guang-Bin; Liu, Peng

    2013-01-01

    A theory based on equivalent circuit was proposed to demonstrate that magnetodielectric (MDE) effect and electric-induced magnetic permeability (EIMP) exist in the magnetoelectric composite. Both MDE and EIMP are sensitive to the amplitude of inspiring signal. They were researched in a simple Pb(Zr,Ti)O3/Terfenol-D laminate composite experimentally. A large MDE coefficient over 85% was found near the resonance frequency under a low magnetic field of 40 Oe. The EIMP was also observed in the composite. They are mainly originated from the magnetoelectric coupling between the piezoelectric and magnetostrictive components. These results are significant in the device applications of modulating dielectric constant and magnetic permeability at room temperature.

  13. Analysis of Signaling Endosome Composition and Dynamics Using SILAC in Embryonic Stem Cell-Derived Neurons*

    PubMed Central

    Debaisieux, Solène; Encheva, Vesela; Chakravarty, Probir; Snijders, Ambrosius P.; Schiavo, Giampietro

    2016-01-01

    Neurons require efficient transport mechanisms such as fast axonal transport to ensure neuronal homeostasis and survival. Neurotrophins and their receptors are conveyed via fast axonal retrograde transport of signaling endosomes to the soma, where they elicit transcriptional responses. Despite the essential roles of signaling endosomes in neuronal differentiation and survival, little is known about their molecular identity, dynamics, and regulation. Gaining a better mechanistic understanding of these organelles and their kinetics is crucial, given the growing evidence linking vesicular trafficking deficits to neurodegeneration. Here, we exploited an affinity purification strategy using the binding fragment of tetanus neurotoxin (HCT) conjugated to monocrystalline iron oxide nanoparticles (MIONs), which in motor neurons, is transported in the same carriers as neurotrophins and their receptors. To quantitatively assess the molecular composition of HCT-containing signaling endosomes, we have developed a protocol for triple Stable Isotope Labeling with Amino acids in Cell culture (SILAC) in embryonic stem cell-derived motor neurons. After HCT internalization, retrograde carriers were magnetically isolated at different time points and subjected to mass-spectrometry and Gene Ontology analyses. This purification strategy is highly specific, as confirmed by the presence of essential regulators of fast axonal transport in the make-up of these organelles. Our results indicate that signaling endosomes undergo a rapid maturation with the acquisition of late endosome markers following a specific time-dependent kinetics. Strikingly, signaling endosomes are specifically enriched in proteins known to be involved in neurodegenerative diseases and neuroinfection. Moreover, we highlighted the presence of novel components, whose precise temporal recruitment on signaling endosomes might be essential for proper sorting and/or transport of these organelles. This study provides the first

  14. Cutting Edge: Retinoic Acid Signaling in B Cells Is Essential for Oral Immunization and Microflora Composition.

    PubMed

    Pantazi, Eirini; Marks, Ellen; Stolarczyk, Emilie; Lycke, Nils; Noelle, Randolph J; Elgueta, Raul

    2015-08-15

    Retinoic acid (RA) is a critical regulator of the intestinal adaptive immune response. However, the intrinsic impact of RA on B cell differentiation in the regulation of gut humoral immunity in vivo has never been directly shown. To address this issue, we have been able to generate a mouse model where B cells specifically express a dominant-negative receptor α for RA. In this study, we show that the silencing of RA signaling in B cells reduces the numbers of IgA(+) Ab-secreting cells both in vitro and in vivo, suggesting that RA has a direct effect on IgA plasma cell differentiation. Moreover, the lack of RA signaling in B cells abrogates Ag-specific IgA responses after oral immunization and affects the microbiota composition. In conclusion, these results suggest that RA signaling in B cells through the RA receptor α is important to generate an effective gut humoral response and to maintain a normal microbiota composition. PMID:26163586

  15. Matrix composition and mechanics direct proangiogenic signaling from mesenchymal stem cells.

    PubMed

    Abdeen, Amr A; Weiss, Jared B; Lee, Junmin; Kilian, Kristopher A

    2014-10-01

    The secretion of trophic factors that promote angiogenesis from mesenchymal stem cells (MSCs) is a promising cell-based therapeutic treatment. However, clinical efficacy has proved variable, likely on account of ill-defined cell delivery formulations and the inherent complexity of cellular secretion. Here we show how controlling the mechanical properties and protein composition of the extracellular matrix (ECM) surrounding MSCs can guide proangiogenic signaling. Conditioned media from MSCs adherent to polyacrylamide hydrogel functionalized with fibronectin, collagen I, or laminin was applied to 3D matrigel cultures containing human microvascular endothelial cells (HMVECs). The degree of tubulogenesis in HMVECs is shown to depend on both the substrate rigidity and matrix protein composition. MSCs cultured on fibronectin-modified hydrogels show a stiffness dependence in proangiogenic signaling with maximum influence on tubulogenesis observed from 40 kPa conditioned media, twofold higher than commercially available cocktails of growth factors. Quantitative real-time-polymerase chain reaction reveals stiffness-dependent expression of multiple factors involved in angiogenesis that corroborate the functional tubulogenesis assay. Restricting cell spreading with micropatterned surfaces attenuates the conditioned media effects; however, small-molecule inhibitors of actomyosin contractility do not significantly reduce the functional outcome. This work demonstrates how controlling matrix rigidity and protein composition can influence the secretory profile of MSCs. Model systems that deconstruct the physical and biochemical cues involved in MSC secretion may assist in the design of hydrogel biomaterials for cell-based therapies. PMID:24701989

  16. Experimental and theoretical studies on compositions, structures, and IR and NMR spectra of functionalized protic ionic liquids.

    PubMed

    Cui, Yingna; Yin, Jingmei; Li, Changping; Li, Shenmin; Wang, Ailing; Yang, Guang; Jia, Yingping

    2016-07-20

    The compositions and structures of amine-based functionalized protic ionic liquids (PILs), namely N,N-dimethyl(cyanoethyl)ammonium propionate (DMCEAP) and N,N-dimethyl(hydroxyethyl)ammonium propionate (DMEOAP) have been investigated systematically by IR and (1)H NMR spectroscopy and density functional theory (DFT) calculations. Analysis of the IR spectra suggests that both DMCEAP and DMEOAP are composed of neutral and ionized species in the liquid phase, the former one mainly existing in the state of precursor molecules, and the latter mainly as ion-pairs. The ratio of precursor molecules to ion-pairs in the liquid phase depends on the types of precursors, especially the functional groups of cations. (1)H NMR spectra indicate that there is a dynamic equilibrium between the neutral and ionized species, probably due to the formation of some intermediates in the PILs. The DFT calculations have been carried out to reveal the conformation, and obtain the corresponding IR and (1)H NMR spectra of the neutral and ionized species, so that the theoretical support to the experimental results can be provided. The present study will help understand the properties of PILs and provide guidance for further applications of PILs. PMID:27385035

  17. Temporal changes of mechanical signals and extracellular composition in human intervertebral disc during degenerative progression

    PubMed Central

    Zhu, Qiaoqiao; Gao, Xin; Gu, Weiyong

    2014-01-01

    In this study, a three-dimensional finite element model was used to investigate the changes in tissue composition and mechanical signals within human lumbar intervertebral disc during the degenerative progression. This model was developed based on the cell-activity coupled mechano-electrochemical mixture theory. The disc degeneration was simulated by lowering nutrition levels at disc boundaries, and the temporal and spatial distributions of the fixed charge density, water content, fluid pressure, Von Mises stress, and disc deformation were analyzed. Results showed that fixed charge density, fluid pressure, and water content decreased significantly in the nucleus pulposus (NP) and the inner to middle annulus fibrosus (AF) regions of the degenerative disc. It was found that, with degenerative progression, the Von Mises stress (relative to that at healthy state) increased within the disc, with a larger increase in the outer AF region. Both the disc volume and height decreased with the degenerative progression. The predicted results of fluid pressure change in the NP were consistent with experimental findings in the literature. The knowledge of the variations of temporal and spatial distributions of composition and mechanical signals within the human IVDs provide a better understanding of the progression of disc degeneration. PMID:25305690

  18. Characterization of the effects of water and disbond on ultrasonic signals in honeycomb composite structures

    NASA Astrophysics Data System (ADS)

    Edwards, A. K.

    The flight control surfaces of the CF188 Hornet are composed of carbon/epoxy skin and aluminum honeycomb core composite material, which has a known susceptibility to water ingress. The rudder is most commonly affected and it is suspected that past in-flight failures have occurred due to the amount of bond degradation between the skin and core. Current inspection techniques involve the use of through-transmission ultrasonic testing. The presence of water within the core, however, provides coupling for the transmission of sound, which can result in the masking of certain disbonded areas. In this study, neutron radiography was used to detect the precise location of water within a test rudder. Through-transmission C-Scan ultrasonic testing was also carried out. Examination of the individual A-Scans revealed that two time-separated signals occurred where water was present. The signal from the sound that travelled down the aluminum core cell walls occurred earlier in time due to the higher velocity of sound in aluminum. The signal from the sound that travelled through the water occurred later as the velocity in water is approximately one quarter of the velocity in aluminum. Analysis of time-gated aluminum signals in the form of C-Scan amplitude or energy plots strongly suggested that the identification of areas of disbond, when water was present, is possible. This identification was achievable since the ultrasound transmission intensity for aluminum bonded to epoxy is three times that in the case of disbond, when water is present between the epoxy and aluminum.

  19. A HIGH SIGNAL-TO-NOISE RATIO COMPOSITE SPECTRUM OF GAMMA-RAY BURST AFTERGLOWS

    SciTech Connect

    Christensen, L.; Fynbo, J. P. U.; Prochaska, J. X.; Jakobsson, P.

    2011-02-01

    We present a composite spectrum of 60 long duration gamma-ray burst (GRB) afterglows with redshifts in the range 0.35 < z < 6.7 observed with low-resolution optical spectra. The composite spectrum covers the wavelength range 700-6600 A in the rest frame and has a mean signal-to-noise ratio of 150 per 1 A pixel and reaches a maximum of {approx}300 in the range 2500-3500 A. Equivalent widths are measured from metal absorption lines from the Ly{alpha} line to {approx}5200 A, and associated metal and hydrogen lines are identified between the Lyman break and Ly{alpha} line. The average transmission within the Lyman forest is consistent with that found along quasar lines of sight. We find a temporal variation in fine-structure lines when dividing the sample into bursts observed within 2 hr from their trigger and those observed later. Other lines in the predominantly neutral gas show variations too, but this is most likely a random effect caused by weighting of individual strong absorption lines and which mimics a temporal variation. Bursts characterized with high- or low-prompt GRB energy release produce afterglows with similar absorption line strengths, and likewise for bursts with bright or faint optical afterglows. Bursts defined as dark from their optical to X-ray spectral index have stronger absorption lines relative to the optically bright bursts. The composite spectrum has strong Ca II and Mg II absorption lines as commonly found in dusty galaxies, however, we find no evidence for dust or a significant molecular content based on the non-detection of diffuse interstellar bands. Compared to starburst galaxy spectra, the GRB composite has much stronger fine-structure lines, while metal absorption lines are weaker.

  20. A High Signal-to-noise Ratio Composite Spectrum of Gamma-ray Burst Afterglows

    NASA Astrophysics Data System (ADS)

    Christensen, L.; Fynbo, J. P. U.; Prochaska, J. X.; Thöne, C. C.; de Ugarte Postigo, A.; Jakobsson, P.

    2011-02-01

    We present a composite spectrum of 60 long duration gamma-ray burst (GRB) afterglows with redshifts in the range 0.35 < z < 6.7 observed with low-resolution optical spectra. The composite spectrum covers the wavelength range 700-6600 Å in the rest frame and has a mean signal-to-noise ratio of 150 per 1 Å pixel and reaches a maximum of ~300 in the range 2500-3500 Å. Equivalent widths are measured from metal absorption lines from the Lyα line to ~5200 Å, and associated metal and hydrogen lines are identified between the Lyman break and Lyα line. The average transmission within the Lyman forest is consistent with that found along quasar lines of sight. We find a temporal variation in fine-structure lines when dividing the sample into bursts observed within 2 hr from their trigger and those observed later. Other lines in the predominantly neutral gas show variations too, but this is most likely a random effect caused by weighting of individual strong absorption lines and which mimics a temporal variation. Bursts characterized with high- or low-prompt GRB energy release produce afterglows with similar absorption line strengths, and likewise for bursts with bright or faint optical afterglows. Bursts defined as dark from their optical to X-ray spectral index have stronger absorption lines relative to the optically bright bursts. The composite spectrum has strong Ca II and Mg II absorption lines as commonly found in dusty galaxies, however, we find no evidence for dust or a significant molecular content based on the non-detection of diffuse interstellar bands. Compared to starburst galaxy spectra, the GRB composite has much stronger fine-structure lines, while metal absorption lines are weaker.

  1. Relation of the multilocus genetic composite reflecting high dopamine signaling capacity to future increases in BMI☆

    PubMed Central

    Yokum, Sonja; Marti, C. Nathan; Smolen, Andrew; Stice, Eric

    2014-01-01

    Because food intake exerts its rewarding effect by increasing dopamine (DA) signaling in reward circuitry, it theoretically follows that individuals with a greater number of genotypes putatively associated with high DA signaling capacity are at increased risk for overeating and subsequent weight gain. We tested the association between the multilocus genetic composite risk score, defined by the total number of genotypes putatively associated with greater DA signaling capacity (i.e. TaqIA A2 allele, DRD2-141C Ins/Del and Del/Del genotypes, DRD4-S allele, DAT1-S allele, and COMT Val/Val genotype), and future increases in Body Mass Index (BMI) in three prospective studies. Participants in Study 1 (N = 30; M age = 15.2; M baseline BMI = 26.9), Study 2 (N = 34; M age = 20.9; M baseline BMI = 28.2), and Study 3 (N = 162; M age = 15.3, M baseline BMI = 20.8) provided saliva samples from which epithelial cells were collected, permitting DNA extraction. The multilocus genetic composite risk score was associated with future increases in BMI in all three studies (Study 1, r = 0.37; Study 2, r = 0.22; Study 3, r = 0.14) and the overall sample (r = 0.19). DRD4-S was associated with increases in BMI in Study 1 (r = 0.42), Study 2 (r = 0.27), and in the overall sample (r = 0.17). DAT1-S was associated with increases in BMI in Study 3 (r = 0.17) and in the overall sample (r = 0.12). There were no associations between the other genotypes (TaqIA, COMT, and DRD2-141C) and change in BMI over 2-year follow-up. Data suggest that individuals with a genetic propensity for greater DA signaling capacity are at risk for future weight gain and that combining alleles that theoretically have a similar function may provide a more reliable method of modeling genetic risk associated with future weight gain than individual genotypes. PMID:25523644

  2. Iron nanotube-silica composite (ZVI-S-PCAT modified silica composite) preparation, characterization and application as a recyclable catalytic system for 5-membered ring organic transformations.

    PubMed

    Kour, Gurpreet; Gupta, Monika; Vishwanathan, B; Thirunavukkarasu, K

    2015-09-01

    Iron nanotube silica composite have been synthesized and studied through particle-size analysis, FTIR, SEM-EDX, TEM, XRD, UV, VSM, TGA-DTA and XPS techniques. The application of nanoframeworks as sustainable recyclable catalytic systems has been observed for azole cyclic ring organic transformations. The good reaction yields and characterization through (1)H NMR, (13)C NMR and mass analysis support the performance of the nanoframeworks. We also present here the synthesis of two novel compounds. Also the prepared nanoframework has been observed to show soft magnetism which provides a scope to be used in sensing devices. PMID:26228908

  3. Disposable electrochemical immunosensor by using carbon sphere/gold nanoparticle composites as labels for signal amplification.

    PubMed

    Xu, Qiunan; Yan, Feng; Lei, Jianping; Leng, Chuan; Ju, Huangxian

    2012-04-16

    This work designed a simple, sensitive, and low-cost immunosensor for the detection of protein marker by using a carbon sphere/gold nanoparticle (CNS/AuNP) composite as an electrochemical label. The nanoscale carbon spheres, prepared with a hydrothermal method by using glucose as raw material, were used to load AuNPs for labeling antibody by electrostatic interaction, which provided a feasible pathway for electron transfer due to the remarkable conductivity. The disposable immunosensor was constructed by coating a polyethylene glycol (PEG) film on a screen-printed carbon-working electrode and then immobilizing capture antibody on the film. With a sandwich-type immunoassay format, the analyte and then the CNS/AuNP-labeled antibody were successively bound to the immunosensor. The bound AuNPs were finally electro-oxidized in 0.1  M HCl to produce AuCl(4)(-) for differential pulse voltammetric (DPV) detection. The high-loading capability of AuNPs on CNS for the sandwich-type immunorecognition led to obvious signal amplification. By using human immunoglobulin G (IgG) as model target, the DPV signal of AuNPs after electro-oxidized at optimal potential of +1.40 V for 40 s showed a wide linear dependence on the logarithm of target concentration ranging from 10 pg  mL(-1) to 10 ng  mL(-1). The detection limit was around 9 pg  mL(-1). The immunosensor showed excellent analytical performance with cost effectivity, good fabrication reproducibility, and acceptable precision and accuracy, providing significant potential application in clinical analysis. PMID:22438025

  4. Tipping points and early warning signals in the genomic composition of populations induced by environmental changes

    PubMed Central

    Aguirre, Jacobo; Manrubia, Susanna

    2015-01-01

    We live in an ever changing biosphere that faces continuous and often stressing environmental challenges. From this perspective, much effort is currently devoted to understanding how natural populations succeed or fail in adapting to evolving conditions. In a different context, many complex dynamical systems experience critical transitions where their dynamical behaviour or internal structure changes suddenly. Here we connect both approaches and show that in rough and correlated fitness landscapes, population dynamics shows flickering under small stochastic environmental changes, alerting of the existence of tipping points. Our analytical and numerical results demonstrate that transitions at the genomic level preceded by early-warning signals are a generic phenomenon in constant and slowly driven landscapes affected by even slight stochasticity. As these genomic shifts are approached, the time to reach mutation-selection equilibrium dramatically increases, leading to the appearance of hysteresis in the composition of the population. Eventually, environmental changes significantly faster than the typical adaptation time may result in population extinction. Our work points out several indicators that are at reach with current technologies to anticipate these sudden and largely unavoidable transitions. PMID:25962603

  5. In vivo localized 1H NMR spectroscopy at 11.7 Tesla

    NASA Astrophysics Data System (ADS)

    Crozier, Stuart; Field, James; Brereton, Ian M.; Moxon, Leith N.; Shannon, Gerald F.; Doddrell, David M.

    The SPACE volume-selection technique has been used to acquire high-resolution 1H spectra from the brain of neonate mice at 11.7 T (500 MHz). Spectra were acquired from voxels smaller than 20 μl. The spectra display elevated intensities of resonances arising from taurine and reduced intensities of those arising from N-acetylaspartate, when compared to those of mature animals, correlating well with in vitro studies. An integrated probe design consisting of separate transmission and reception RF coils and linear gradient coils is described. Comments are made concerning the advantages and disadvantages of performing gradient-encoded localized spectroscopy at this field strength.

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

    PubMed

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

    2012-06-01

    (1)H nuclear magnetic resonance (NMR)-based metabonomics has been used to characterize the metabolic profiles of cervical intraepithelial neoplasia (CIN) and cervical squamous cell carcinoma (CSCC). Principal component analysis (PCA) and orthogonal partial least-squares discriminant analysis (OPLS-DA) were used to model the systematic variation related to patients with CIN or CSCC with healthy controls. Potential metabolic biomarkers were identified using database comparisons, and the one-way analysis of variance (ANOVA) test was used to examine the significance of the metabolites. Compared with plasma obtained from the healthy controls, plasma from patients with CIN had higher levels of very-low density lipoprotein (VLDL), acetone, unsaturated lipid and carnitine, together with lower levels of creatine, lactate, isoleucine, leucine, valine, alanine, glutamine, histidine, glycine, acetylcysteine, myo-inositol, choline and glycoprotein. Plasma from patients with CSCC had higher levels of acetate and formate, together with lower levels of creatine, lactate, isoleucine, leucine, valine, alanine, glutamine, histidine and tyrosine compared with the plasma of the healthy controls. In addition, compared with the plasma of patients with CIN, the plasma of CSCC patients had higher levels of acetate, formate, lactate, isoleucine, leucine, valine, alanine, glutamine, histidine, tyrosine, acetylcysteine, myo-inositol, glycoprotein, α-glucose and β-glucose, together with lower levels of acetone, unsaturated lipid and carnitine. Moreover, the profiles showed high feasibility and specificity by statistical analysis with OPLS-DA compared to the Thinprep cytology test (TCT) by setting the histopathological outcome as standard. The metabolic profile obtained for cervical cancer is significant, even for the precancerous disease. This suggests a systemic metabolic response to cancer, which may be used to identify potential early diagnostic biomarkers of the cancer and to establish clinical diagnostic methods. PMID:22969997

  7. 1H NMR spectra part 31: 1H chemical shifts of amides in DMSO solvent.

    PubMed

    Abraham, Raymond J; Griffiths, Lee; Perez, Manuel

    2014-07-01

    The (1)H chemical shifts of 48 amides in DMSO solvent are assigned and presented. The solvent shifts Δδ (DMSO-CDCl3 ) are large (1-2 ppm) for the NH protons but smaller and negative (-0.1 to -0.2 ppm) for close range protons. A selection of the observed solvent shifts is compared with calculated shifts from the present model and from GIAO calculations. Those for the NH protons agree with both calculations, but other solvent shifts such as Δδ(CHO) are not well reproduced by the GIAO calculations. The (1)H chemical shifts of the amides in DMSO were analysed using a functional approach for near ( ≤ 3 bonds removed) protons and the electric field, magnetic anisotropy and steric effect of the amide group for more distant protons. The chemical shifts of the NH protons of acetanilide and benzamide vary linearly with the π density on the αN and βC atoms, respectively. The C=O anisotropy and steric effect are in general little changed from the values in CDCl3. The effects of substituents F, Cl, Me on the NH proton shifts are reproduced. The electric field coefficient for the protons in DMSO is 90% of that in CDCl3. There is no steric effect of the C=O oxygen on the NH proton in an NH…O=C hydrogen bond. The observed deshielding is due to the electric field effect. The calculated chemical shifts agree well with the observed shifts (RMS error of 0.106 ppm for the data set of 257 entries). PMID:24824670

  8. 1H NMR metabolomics study of metastatic melanoma in C57BL/6J mouse spleen

    DOE PAGESBeta

    Wang, Xuan; Hu, Mary Y.; Feng, Ju; Liu, Maili; Hu, Jian Z.

    2014-04-03

    Melanoma is a malignant tumor of melanocytes. Although extensive investigations have been done to study metabolic changes in primary melanoma in vivo and in vitro, little effort has been devoted to metabolic profiling of metastatic tumors in organs other than lymph nodes. In this work, NMR-based metabolomics combined with multivariate data analysis is used to study metastatic B16-F10 melanoma in C57BL/6J mouse spleen. Principal Component Analysis (PCA), an unsupervised multivariate data analysis method, is used to detect possible outliers, while Orthogonal Projection to Latent Structure (OPLS), a supervised multivariate data analysis method, is employed to find important metabolites responsible formore » discriminating the control and the melanoma groups. Two different strategies, i.e., spectral binning and spectral deconvolution, are used to reduce the original spectral data before statistical analysis. Spectral deconvolution is found to be superior for identifying a set of discriminatory metabolites between the control and the melanoma groups, especially when the sample size is small. OPLS results show that the melanoma group can be well separated from its control group. It is found that taurine, glutamate, aspartate, O-Phosphoethanolamine, niacinamide ,ATP, lipids and glycerol derivatives are decreased statistically and significantly while alanine, malate, xanthine, histamine, dCTP, GTP, thymidine, 2'-Deoxyguanosine are statistically and significantly elevated. Furthermore, these significantly changed metabolites are associated with multiple biological pathways and may be potential biomarkers for metastatic melanoma in spleen.« less

  9. Importance of Purity Evaluation and the Potential of Quantitative 1H NMR as a Purity Assay

    PubMed Central

    2015-01-01

    In any biomedical and chemical context, a truthful description of chemical constitution requires coverage of both structure and purity. This qualification affects all drug molecules, regardless of development stage (early discovery to approved drug) and source (natural product or synthetic). Purity assessment is particularly critical in discovery programs and whenever chemistry is linked with biological and/or therapeutic outcome. Compared with chromatography and elemental analysis, quantitative NMR (qNMR) uses nearly universal detection and provides a versatile and orthogonal means of purity evaluation. Absolute qNMR with flexible calibration captures analytes that frequently escape detection (water, sorbents). Widely accepted structural NMR workflows require minimal or no adjustments to become practical 1H qNMR (qHNMR) procedures with simultaneous qualitative and (absolute) quantitative capability. This study reviews underlying concepts, provides a framework for standard qHNMR purity assays, and shows how adequate accuracy and precision are achieved for the intended use of the material. PMID:25295852

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

    NASA Astrophysics Data System (ADS)

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

    2013-01-01

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

  11. Relationships between 1H NMR Relaxation Data and Some Technological Parameters of Meat: A Chemometric Approach

    NASA Astrophysics Data System (ADS)

    Brown, Robert J. S.; Capozzi, Francesco; Cavani, Claudio; Cremonini, Mauro A.; Petracci, Massimiliano; Placucci, Giuseppe

    2000-11-01

    In this paper chemometrics (ANOVA and PCR) is used to measure unbiased correlations between NMR spin-echo decays of pork M. Longissimus dorsi obtained through Carr-Purcell-Meiboom-Gill (CPMG) experiments at low frequency (20 MHz) and the values of 14 technological parameters commonly used to assess pork meat quality. On the basis of the ANOVA results, it is also found that the CPMG decays of meat cannot be best interpreted with a "discrete" model (i.e., by expanding the decays in a series of a discrete number of exponential components, each with a different transverse relaxation time), but rather with a "continuous" model, by which a continuous distribution of T2's is allowed. The latter model also agrees with literature histological results.

  12. Main-chain-directed strategy for the assignment of /sup 1/H NMR spectra of proteins

    SciTech Connect

    Englander, S.W.; Wand, A.J.

    1987-09-22

    A strategy for assigning the resonances in two-dimensional (2D) NMR spectra of proteins is described. The method emphasizes the analysis of through-space relationships between protons by use of the two-dimensional nuclear Overhauser effect (NOE) experiment. NOE patterns used in the algorithm were derived from a statistical analysis of the combinations of short proton-proton distances observed in the high-resolution crystal structures of 21 proteins. One starts with a search for authentic main-chain NH-C/sub ..cap alpha../H-C/sub ..beta../H J-coupled units, which can be found with high reliability. The many main-chain units of a protein are then placed in their proper juxtaposition by recognition of predefined NOE connectivity patterns. To discover these connectivities, the 2D NOE spectrum is examined, in a prescribed order, for the distinct NOE patterns characteristic of helices, sheets, turns, and extended chain. Finally, the recognition of a few amino acid side-chain types places the discovered secondary structure elements within the polypeptide sequences. Unlike the sequential assignment approach, the main-chain-directed strategy does not rely on the difficult task of recognizing many side-chain spin systems in J-correlated spectra, the assignment process is not in general sequential with the polypeptide chain, and the prescribed connectivity patterns are cyclic rather than linear. The latter characteristic avoids ambiguous branch points in the analysis and imposed an internally confirmatory property on each forward step.

  13. Temperature dependence of 1H NMR relaxation time, T2, for intact and neoplastic plant tissues

    NASA Astrophysics Data System (ADS)

    Lewa, Czesław J.; Lewa, Maria

    Temperature dependences of the spin-spin proton relaxation time, T2, have been shown for normal and tumorous tissues collected from kalus culture Nicotiana tabacum and from the plant Kalanchoe daigremontiana. For neoplastic plant tissues, time T2 was increased compared to that for intact plants, a finding similar to that for animal and human tissues. The temperature dependences obtained were compared to analogous relations observed with animal tissues.

  14. Improving the efficiency of quantitative (1)H NMR: an innovative external standard-internal reference approach.

    PubMed

    Huang, Yande; Su, Bao-Ning; Ye, Qingmei; Palaniswamy, Venkatapuram A; Bolgar, Mark S; Raglione, Thomas V

    2014-01-01

    The classical internal standard quantitative NMR (qNMR) method determines the purity of an analyte by the determination of a solution containing the analyte and a standard. Therefore, the standard must meet the requirements of chemical compatibility and lack of resonance interference with the analyte as well as a known purity. The identification of such a standard can be time consuming and must be repeated for each analyte. In contrast, the external standard qNMR method utilizes a standard with a known purity to calibrate the NMR instrument. The external standard and the analyte are measured separately, thereby eliminating the matter of chemical compatibility and resonance interference between the standard and the analyte. However, the instrumental factors, including the quality of NMR tubes, must be kept the same. Any deviations will compromise the accuracy of the results. An innovative qNMR method reported herein utilizes an internal reference substance along with an external standard to assume the role of the standard used in the traditional internal standard qNMR method. In this new method, the internal reference substance must only be chemically compatible and be free of resonance-interference with the analyte or external standard whereas the external standard must only be of a known purity. The exact purity or concentration of the internal reference substance is not required as long as the same quantity is added to the external standard and the analyte. The new method reduces the burden of searching for an appropriate standard for each analyte significantly. Therefore the efficiency of the qNMR purity assay increases while the precision of the internal standard method is retained. PMID:24013124

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

    PubMed Central

    HASIM, AYSHAMGUL; ALI, MAYINUER; MAMTIMIN, BATUR; MA, JUN-QI; LI, QIAO-ZHI; ABUDULA, ABULIZI

    2012-01-01

    1H nuclear magnetic resonance (NMR)-based metabonomics has been used to characterize the metabolic profiles of cervical intraepithelial neoplasia (CIN) and cervical squamous cell carcinoma (CSCC). Principal component analysis (PCA) and orthogonal partial least-squares discriminant analysis (OPLS-DA) were used to model the systematic variation related to patients with CIN or CSCC with healthy controls. Potential metabolic biomarkers were identified using database comparisons, and the one-way analysis of variance (ANOVA) test was used to examine the significance of the metabolites. Compared with plasma obtained from the healthy controls, plasma from patients with CIN had higher levels of very-low density lipoprotein (VLDL), acetone, unsaturated lipid and carnitine, together with lower levels of creatine, lactate, isoleucine, leucine, valine, alanine, glutamine, histidine, glycine, acetylcysteine, myo-inositol, choline and glycoprotein. Plasma from patients with CSCC had higher levels of acetate and formate, together with lower levels of creatine, lactate, isoleucine, leucine, valine, alanine, glutamine, histidine and tyrosine compared with the plasma of the healthy controls. In addition, compared with the plasma of patients with CIN, the plasma of CSCC patients had higher levels of acetate, formate, lactate, isoleucine, leucine, valine, alanine, glutamine, histidine, tyrosine, acetylcysteine, myo-inositol, glycoprotein, α-glucose and β-glucose, together with lower levels of acetone, unsaturated lipid and carnitine. Moreover, the profiles showed high feasibility and specificity by statistical analysis with OPLS-DA compared to the Thinprep cytology test (TCT) by setting the histopathological outcome as standard. The metabolic profile obtained for cervical cancer is significant, even for the precancerous disease. This suggests a systemic metabolic response to cancer, which may be used to identify potential early diagnostic biomarkers of the cancer and to establish clinical diagnostic methods. PMID:22969997

  16. Early Stage Diagnosis of Oral Cancer Using 1H NMR-Based Metabolomics12

    PubMed Central

    Tiziani, Stefano; Lopes, Victor; Günther, Ulrich L

    2009-01-01

    Oral cancer is the eighth most common cancer worldwide and represents a significant disease burden. If detected at an early stage, survival from oral cancer is better than 90% at 5 years, whereas late stage disease survival is only 30%. Therefore, there is an obvious clinical utility for novel metabolic markers that help to diagnose oral cancer at an early stage and to monitor treatment response. In the current study, blood samples of oral cancer patients were analyzed using nuclear magnetic resonance spectroscopy to derive a metabolic signature for oral cancer. Using multivariate chemometric analysis, we obtained an excellent discrimination between serum samples from cancer patients and from a control group and could also discriminate between different stages of disease. The metabolic profile obtained for oral cancer is significant, even for early stage disease and relatively small tumors. This suggests a systemic metabolic response to cancer, which bears great potential for early diagnosis. PMID:19242608

  17. Qualitative and Quantitative Control of Carbonated Cola Beverages Using 1H NMR Spectroscopy

    PubMed Central

    2012-01-01

    1H Nuclear magnetic resonance (NMR) spectroscopy (400 MHz) was used in the context of food surveillance to develop a reliable analytical tool to differentiate brands of cola beverages and to quantify selected constituents of the soft drinks. The preparation of the samples required only degassing and addition of 0.1% of TSP in D2O for locking and referencing followed by adjustment of pH to 4.5. The NMR spectra obtained can be considered as “fingerprints” and were analyzed by principal component analysis (PCA). Clusters from colas of the same brand were observed, and significant differences between premium and discount brands were found. The quantification of caffeine, acesulfame-K, aspartame, cyclamate, benzoate, hydroxymethylfurfural (HMF), sulfite ammonia caramel (E 150D), and vanillin was simultaneously possible using external calibration curves and applying TSP as internal standard. Limits of detection for caffeine, aspartame, acesulfame-K, and benzoate were 1.7, 3.5, 0.8, and 1.0 mg/L, respectively. Hence, NMR spectroscopy combined with chemometrics is an efficient tool for simultaneous identification of soft drinks and quantification of selected constituents. PMID:22356160

  18. The structure of polycaprolactone-clay nanocomposites investigated by 1H NMR relaxometry.

    PubMed

    Monteiro, Mariana S S B; Rodrigues, Claudia Lopes; Neto, Roberto P C; Tavares, Maria Inês Bruno

    2012-09-01

    Nanocomposites based on polycaprolactone (PCL), containing concentrations of 1, 3 and 5 wt% of sodium montmorillonite (NT-25) and organo-modified montmorillonite clay, with three different salts (Viscogel B7, Viscogel S4 and Viscogel B8), were prepared employing the solution intercalation method using chloroform. The PCL nanocomposites were characterized by relaxometry, through determination of the hydrogen spin-lattice relaxation times using low-field nuclear magnetic resonance (NMR). Conventional X-ray diffraction (XDR) was also used to measure the basal space of the nanoclay. The proton spin-lattice relaxation parameters showed that hybrid nanocomposites were formed, containing different parts of intercalated and exfoliated organoclay. The proton T1rhoH also indicated changes in the microstructure, organization and the molecular mobility of the hybrid materials. NMR relaxometry is a good way to evaluate nanomaterials because it provides complementary information, since it is measured in a different time scale. Furthermore, differential scanning calorimetry and thermogravimetric analysis were also used to investigate the crystallization and thermal behavior of the nanocomposites, respectively. All materials had low crystallization temperature (Tc) and the melting temperature (Tm) were very close to that of the PCL matrix, but the degree of crystallinity of the nanocomposites decreased. TGA analysis demonstrated that montmorillonite accelerates PCL's decomposition while unmodified montmorillonite has the opposite effect. PMID:23035469

  19. 1H-NMR, dielectric and calorimetric studies of molecular motions in m-nitroaniline crystal

    NASA Astrophysics Data System (ADS)

    Szostak, M. Magdalena; Wójcik, Grażyna; Gallier, Jean; Bertault, Marcel; Freundlich, Piotr; Kołodziej, Hubert A.

    1998-04-01

    Spin-lattice relaxation time, T1, spin-lattice relaxation time in the rotating frame, T1 ρ, and the second moment of the resonance line measurements at 80 MHz and over the 190-380 K temperature range are reported for protons in the optically nonlinear material m-nitroaniline ( m-NA). T1 has also been measured for samples irradiated by low energy and low intensity radiation. The real and imaginary parts of electric permittivity as well as tan  δ have been recorded in the 80-380 K temperature range at frequencies ranging from 100 Hz to 1.0 MHz. DSC measurements have been performed in the 110-387 K temperature range. Two phase transitions have been found: A glassy to rotative transition at 160 K and a plastic to plastic transformation at 365 K. The main feature of the m-NA crystal is that its plasticity continues to grow as the temperature increases. The reorientations of phenyl rings, the -NH 2 group proton 180° jumps, the lattice distortions caused by anisotropic thermal expansion and the cooperative reorientations of big molecular aggregates are thought to be the reasons for phase transitions and for the subsequent intermolecular charge transfer. The results are discussed with respect to optical second harmonic generation and near-IR photochemical reaction found in the m-NA crystal.

  20. Effects of high fructose and salt feeding on systematic metabonome probed via (1) H NMR spectroscopy.

    PubMed