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Sample records for 1h nmr study

  1. Dynamic 1H NMR Studies of Schiff Base Derivatives

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

    2016-01-01

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

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

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

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

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

  4. 1H NMR spectroscopic studies establish that heparanase is a retaining glycosidase

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

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

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

    2014-01-03

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

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

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

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

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

  8. 23Na and 1H NMR studies on melittin channels activated by tricyclic tranquilizers.

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

    1992-01-01

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

  9. 1H NMR Cryoporometry Study of the Melting Behavior of Water in White Cement

    Boguszyńska, Joanna; Tritt-Goc, Jadwiga

    2004-09-01

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

  10. 1H NMR studies of selective interactions of norfloxacin with double-stranded DNA

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

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

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

    2009-01-01

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

  12. 1H NMR study of thermotropic phase transition in aqueous polymer solutions

    Spěváček, Jiří; Hanyková, L.

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

  13. 1H NMR studies of insulin: histidine residues, metal binding, and dissociation in alkaline solution

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

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

    Bouyssy, P X

    2001-01-01

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

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

    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.

  16. 1H and 13C NMR studies of palladium(2) and platinium(2) complexes with S-Methyl-L-Cysteine

    Our recent 1H NMR studies on Pd(2)-S-Methyl-L-Cysteine(SMC) complexes have shown that the use of a conformational analysis to establish the complexed species existing in solution may provide clearer results than considering the proton chemical shift only. However, the use of the vicinal coupling constant of ABC spectrum of αCH-βCH2 proton unit to estimate the rotational isomer fractions, may contain some ambiguity, especially on the proton assignment of the methylene group. For this reason 13C NMR method has been applied to study these systems. (author)

  17. 1H NMR in a-Si

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

    1982-10-01

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

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

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

    2010-01-01

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

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

    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. Myosin catalyzed ATP hydrolysis elucidated by 31P NMR kinetic studies and 1H PFG-diffusion measurements

    Song, Zhiyan; Parker, Kari J.; Enoh, Idorenyin; Zhao, Hua; Olubajo, Olarongbe

    2009-01-01

    We conducted 31P NMR kinetic studies and 1H-diffusion measurements on myosin-catalyzed hydrolysis of adenosine triphosphate (ATP) under varied conditions. The data elucidate well the overall hydrolysis rate and various factors that significantly impact the reaction. We found that the enzymatic hydrolysis of ATP to adenosine diphosphate (ADP) was followed by ADP hydrolysis, and different nucleotides such as ADP and guanosine triphosphate (GTP) acted as competitors of ATP. Increasing ATP or Mg2...

  1. 1H NMR and rheological studies of the calcium induced gelation process in aqueous low methoxy pectin solutions

    The 1H NMR relaxometry in combination with water proton spin-spin relaxation time measurements and rheology have been applied to study the ionic gelation of 1% W/W aqueous low methoxyl pectin solution induced by divalent Ca2+ cations from a calcium chloride solution. The model-free approach to the analysis of 1H NMR relaxometry data has been used to separate the information on the static (β) and dynamic (τc) behaviour of the system tested. The 1H NMR results confirm that the average mobility of both water and the pectin molecules is largely dependent on the concentration of the cross-linking agent. The character of this dependency (β, τc and T2 vs. CaCl2 concentration ). is consistent with the two stage gelation process of low methoxy pectin, in which the formation of strongly linked dimer associations (in the range of 0-2.5 mM CaCl2) is followed by the appearance of weak inter-dimer aggregations (for CaCl2 ≥ 3.5 mM). The presence of the weak gel structure for the sample with 3.5 mM CaCl2 has been confirmed by rheological measurements. Apart from that, the T1 and T2 relaxation times have been found to be highly sensitive to to the syneresis phenomenon, which can be useful to monitor the low methoxyl pectin gel network stability. (author)

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

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

  3. Synthesis, GC-EIMS, ~1H NMR, ~(13)C NMR, Mechanistic and Thermal Studies of o-Xylylene-α,α'-bis(triphenylphosphinebromide)

    Muddasir Hanif; LU Ping; XU Hai; TIAN Zhi-cheng; YANG Bing; WANG Zhi-ming; TIAN Lei-lei; XU Yuan-ze; XIE Zeng-qi; MA Yu-guang

    2009-01-01

    Organophosphorous compounds containing phosphorus as an integral part have been widely used in industry, organic synthesis and optoelectronics. o-Xylylene-α,α'-bis(triphenylphosphinebromide)(OXBTPPB) is a facile reagent to convert o-quinones(e.g., 9,10-phenanthrenequinone) into polycyclic aromatic hydrocarbons(PAHs). Herein lies an improved synthetic route to OXBTPPB. The resultant was carefully characterized with GC-EIMS, ~1H NMR, ~(13)C NMR, spectroscopic techniques. The EIMS shows characteristic peaks at m/z=262.4, 183.3, 108.2, 77.1 attributed to the [C_(18)H_(15)P]~+, [C_(18)H_8P]~+, [C_6H_5P]~+, [C_6H_5]~+ ions, respectively. The 1H and ~(13)C NMR spectrum shows well resolved peaks and all the hydrogens and carbons were well-assigned via a combined study of ~1H-~1H COSY, HMBC, and HMQC experiments. The mechanism for the formation of OXBTPPB was proposed based on literature and obtained experimental data. Meanwhile, the thermal stability of OXBTPPB was evaluated with TGA analysis, and an onset decomposition temperature(T_d) was recorded at 323.6℃.

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

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

    2004-01-01

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

  5. Conversion of 2'-substituted chalcones in the presence of BSA as evidenced by (1)H NMR studies.

    Raghav, Neera; Garg, Shweta; Ravish, Indu

    2016-04-01

    The emergence of albumin as a biocatalyst has created continuous interest of researchers for its application not only in the field of asymmetric oxidations and reductions but also in chemical reactions such as additions, condensations and eliminations. In the present work we report the cyclization reactions in presence of an albumin protein, Bovine Serum Albumin (BSA). The work is focused on cyclization of 2'-hydroxychalcone and 2'-aminochalcone to flavanones and azaflavanone, respectively. The results are supported by (1)H NMR studies. PMID:26723247

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

    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.

  7. 1H and 2H NMR study in paramagnetic solutions of Eu3+ nitrate

    The dependence of the spin-lattice rate(1/T1) of 1H and 2H nuclei for the 2.1 T magnetic field of the concentration (from 0.1 to 2.75 mol) of Eu3+ paramagnetic ions in the range from 263 K to 373 K is presented . Also the NMRD profield for the frecuency range from 0.1 to 500 Mhz is showed

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

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

    2005-11-10

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

  9. 1H MAS, 13C CP/MAS, and 2H NMR spectra studies of piperidinium p-chlorobenzoate

    Anomalous H/D isotope effects were detected in the 1H MAS NMR spectra of piperidinium p-chlorobenzoate (C5H10NH 2+⋅ ClC6H4COO − ) upon deuterium substitution of hydrogen atoms which form two kinds of N-H⋯O H-bonds in the crystal; in contrast to these spectra, only slight chemical shifts were recorded in 13C CP/MAS NMR spectra. 2H NMR spectrum of the deuterated sample show quadrupole coupling constants of 148 and 108 kHz, and reveal that there are a few motions contributing to the electric-field modulation of the 2H nucleus. The 1H MAS NMR spectra of piperidinium p-chlrobenzoate-d16 (C5D10ND 2+⋅ ClC6D4COO − ) and -d14 (C5D10NH 2+⋅ ClC6D4COO − ) revealed that the change in the envelope is caused by chemical shifts of each signal upon deuteration. Calculations based on the density-functional-theory showed that the N-H distance along the crystallographic a-axis mainly contributes to the anomalous isotope effects on 1H MAS NMR envelopes.

  10. Investigations of acetaminophen binding to bovine serum albumin in the presence of fatty acid: Fluorescence and 1H NMR studies

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

    2009-04-01

    The binding of acetaminophen to bovine serum albumin (BSA) was studied by the quenching fluorescence method and the proton nuclear magnetic resonance technique ( 1H NMR). For fluorescence measurements 1-anilino-9-naphthalene sulfonate (ANS) hydrophobic probe was used to verify subdomain IIIA as acetaminophen's likely binding site. Three binding sites of acetaminophen in subdomain IIA of bovine serum albumin were found. Quenching constants calculated by the Stern-Volmer modified method were used to estimate the influence of myristic acid (MYR) on the drug binding to the albumin. The influence of [fatty acid]/[albumin] molar ratios on the affinity of the protein towards acetaminophen was described. Changes of chemical shifts and relaxation times of the drug indicated that the presence of MYR inhibits interaction in the AA-albumin complex. It is suggested that the elevated level of fatty acids does not significantly influence the pharmacokinetics of acetaminophen.

  11. (1)H NMR based metabolomics approach to study the toxic effects of dichlorvos on goldfish (Carassius auratus).

    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

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

    Mohamed Haouas

    2016-06-01

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

  13. 1H NMR study of the solvent THF concerning their structural and dynamical properties in chemically Li-intercalated SWNT

    Schmid, Marc R.

    2011-09-01

    Structural and dynamical properties of the THF solvent in single-walled carbon nanotubes intercalated with lithium are investigated by NMR. 1H NMR experiments reveal the existence of two types of inequivalent THF solvent molecules with different chemical environments and dynamical behavior. At low temperatures THF molecules perpendicularly arranged in between adjacent SWNT presumably exhibit a restricted rotation around their dipolar axis. At higher temperatures THF molecules are isotropically rotating and diffusing along the interstitial channels of the SWNT bundles. © 2011 Elsevier B.V. All rights reserved.

  14. Biosynthetic studies of the glycopeptide teicoplanin by 1H and 13C NMR

    Heydorn, Arne; Petersen, Bent O.; Duus, Jens Øllgaard;

    2000-01-01

    The biosynthesis of the glycopeptide antibiotic teicoplanin was studied by growing a teicoplanin producing strain of Actinoplanes teichomyceticus (ATCC 31121) on glucose containing either 34.0% [1-13C]glucose or 9.7% [U- 13C]glucose. The fractional enrichment pattern of teicoplanin produced in the...

  15. 1H NMR studies on molecular motions of 4-aminopyridinium and pyrrolidinium cations in new ferroics.

    Medycki, W; Swiergiel, J; Hołderna-Natkaniec, K; Jurga, K; Jakubas, R

    2004-01-01

    The aim of the study was to check the effect of the cation on the molecular dynamics of the anion, which is not directly observed, in different phases of the following compounds: (C4H8NH2)SbCl6(C4H8NH2)Cl, (C4H8NH2)SbCl6 and (4-apyH)ClO4, (4-apyH)SbCl4. PMID:14698398

  16. 35Cl and 1H NMR study of anion binding to reduced bovine copper-zinc superoxide dismutase

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

  17. Laundering and Deinking Applications of 1H NMR Imaging

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

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

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

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

    1994-02-01

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

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

    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].

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

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

    1992-12-01

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

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

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

    2007-07-15

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

  2. Vibrational and thermodynamic properties and molecular motions in the incommensurate crystal of morpholinium tetrafluoroborate studied by 1H NMR

    Graphical abstract: The N-H...O and N-H...F hydrogen bond system determines the dynamical properties and the phase transitions sequence in [NH2(C2H4)2O][BF4]. Research highlights: → Thermodynamical characteristics of phase transitions in morpholinium tetrafluoroborate. → Dynamics of the [BF4]- groups is responsible for the phase transition mechanism. Proton dynamics of the (NH2)+ group contributes to the spin-lattice relaxation time. - Abstract: Dynamics of molecules in morpholinium tetrafluoroborate, [NH2(C2H4)2O][BF4], has been studied in a wide temperature range by means of AC calorimetry, 1H NMR and infrared spectroscopy. Simultaneously, DFT (density functional theory) calculations of the molecular structure and normal vibration frequencies have been performed by using various functionals for initial structural data of the low temperature phase. Infrared spectra of polycrystalline [NH2(C2H4)2O][BF4] have been analyzed in a frequency range 4000-400 cm-1. Substantial changes in a temperature evolution of internal modes of both morpholinium cations and [BF4]- anions are due to the freezing of these moieties motions below 117 K. A dynamic nonequivalence of protons involved in N-H...F and N-H...O hydrogen bonds has been detected. Heat capacity anomalies around structural phase transitions detected by AC calorimetry (117 and 153 K) have been evaluated and described. A molecular mechanism of the phase transitions is discussed on the basis of presented results.

  3. Vibrational and thermodynamic properties and molecular motions in the incommensurate crystal of morpholinium tetrafluoroborate studied by {sup 1}H NMR

    Owczarek, M. [Faculty of Chemistry, University of Wroclaw, F. Joliot-Curie 14, 50-383 Wroclaw (Poland); Jakubas, R., E-mail: rj@wchuwr.chem.uni.wroc.pl [Faculty of Chemistry, University of Wroclaw, F. Joliot-Curie 14, 50-383 Wroclaw (Poland); Bator, G. [Faculty of Chemistry, University of Wroclaw, F. Joliot-Curie 14, 50-383 Wroclaw (Poland); Pawlukojc, A. [Institute of Nuclear Chemistry and Technology, Dorodna 16, 03-195 Warsaw (Poland); Baran, J. [Institute of Low Temperature and Structural Research of the PAS, Okolna 2, 50-422 Wroclaw (Poland); Przeslawski, J. [Institute of Experimental Physics, University of Wroclaw, Max Born Sq. 9, 50-204 Wroclaw (Poland); Medycki, W. [Institute of Molecular Physics, PAS, Smoluchowskiego 17, 60-179 Poznan (Poland)

    2011-03-18

    Graphical abstract: The N-H...O and N-H...F hydrogen bond system determines the dynamical properties and the phase transitions sequence in [NH{sub 2}(C{sub 2}H{sub 4}){sub 2}O][BF{sub 4}]. Research highlights: {yields} Thermodynamical characteristics of phase transitions in morpholinium tetrafluoroborate. {yields} Dynamics of the [BF{sub 4}]{sup -} groups is responsible for the phase transition mechanism. Proton dynamics of the (NH{sub 2}){sup +} group contributes to the spin-lattice relaxation time. - Abstract: Dynamics of molecules in morpholinium tetrafluoroborate, [NH{sub 2}(C{sub 2}H{sub 4}){sub 2}O][BF{sub 4}], has been studied in a wide temperature range by means of AC calorimetry, {sup 1}H NMR and infrared spectroscopy. Simultaneously, DFT (density functional theory) calculations of the molecular structure and normal vibration frequencies have been performed by using various functionals for initial structural data of the low temperature phase. Infrared spectra of polycrystalline [NH{sub 2}(C{sub 2}H{sub 4}){sub 2}O][BF{sub 4}] have been analyzed in a frequency range 4000-400 cm{sup -1}. Substantial changes in a temperature evolution of internal modes of both morpholinium cations and [BF{sub 4}]{sup -} anions are due to the freezing of these moieties motions below 117 K. A dynamic nonequivalence of protons involved in N-H...F and N-H...O hydrogen bonds has been detected. Heat capacity anomalies around structural phase transitions detected by AC calorimetry (117 and 153 K) have been evaluated and described. A molecular mechanism of the phase transitions is discussed on the basis of presented results.

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

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

    1999-05-01

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

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

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

    2016-10-20

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

  6. Pro-Oxidant Role of Silibinin in DMBA/TPA Induced Skin Cancer: 1H NMR Metabolomic and Biochemical Study

    Sati, Jasmine; Mohanty, Biraja Prasad; Garg, Mohan Lal; Koul, Ashwani

    2016-01-01

    Silibinin, a major bioactive flavonolignan in Silybum marianum, has received considerable attention in view of its anticarcinogenic activity. The present study examines its anticancer potential against 7, 12-dimethylbenz(a)anthracene (DMBA) and 12-O-tetradecanoylphorbol-13-acetate (TPA) induced skin cancer. Male LACA mice were randomly segregated into 4 groups: Control, DMBA/TPA, Silibinin and Silibinin+DMBA/TPA. Tumors in DMBA/TPA and Silibinin+DMBA/TPA groups were histologically graded as squamous cell carcinoma. In the Silibinin+DMBA/TPA group, significant reduction in tumor incidence (23%), tumor volume (64.4%), and tumor burden (84.8%) was observed when compared to the DMBA/TPA group. The underlying protective mechanism of Silibinin action was studied at pre-initiation (2 weeks), post-initiation (10 weeks) and promotion (22 weeks) stages of the skin carcinogenesis. The antioxidant nature of Silibinin was evident at the end of 2 weeks of its treatment. However, towards the end of 10 and 22 weeks, elevated lipid peroxidation (LPO) levels indicate the pro-oxidative nature of Silibinin in the cancerous tissue. TUNEL assay revealed enhanced apoptosis in the Silibinin+DMBA/TPA group with respect to the DMBA/TPA group. Therefore, it may be suggested that raised LPO could be responsible for triggering apoptosis in the Silibinin+DMBA/TPA group. 1H Nuclear Magnetic Resonance (NMR) spectroscopy was used to determine the metabolic profile of the skin /skin tumors. Dimethylamine (DMA), glycerophosphocholine (GPC), glucose, lactic acid, taurine and guanine were identified as the major contributors for separation between the groups from the Principal Component Analysis (PCA) of the metabolite data. Enhanced DMA levels with no alteration in GPC, glucose and lactate levels reflect altered choline metabolism with no marked Warburg effect in skin tumors. However, elevated guanine levels with potent suppression of taurine and glucose levels in the Silibinin+DMBA/TPA group are

  7. /sup 67/Zn and /sup 1/H NMR studies of Zn/sup 2 +/-imidazole and carboxylate complexes

    Shimizu, T. (Chemical Research Inst. of Non-Aqueous Solutions, Katahira, Japan); Kudaka, M.; Hatano, M.

    1982-06-15

    /sup 67/Zn NMR studies of naturally abundant Zn/sup 2 +/-imidazole and carboxylate ligands. Complexes are shown. Thus, quadrupolar relaxation changes in /sup 67/Zn NMR caused by adding imidazole ligands are more remarkable than those by carboxylate ligands. The changes caused by adding less bulky imidazole ligands are more prominent than those caused by a bulky imidazole ligand. Changes in Zn/sup 2 +/ quadrupolar relaxation rate caused by adding a cyclic hexapeptide consisting of L-histidine, L-cystein(Acm) and D-leucine are larger than those by a corresponding linear hexapeptide. Those changes in the quadrupolar relaxation rate of /sup 67/Zn NMR among Zn/sup 2 +/ complexes can be reasonably interpreted in terms of the differences of equilibrium constants of those complexes to a first approximation.

  8. 1H and 13C NMR and electrical conductivity studies on new ionic plastic crystals of tetraalkylammonium tetraethylborate

    Eight plastic crystals of the types NEtxMe(4-x)BEt4 and NEtyPr(4-y)BEt4 (x = 0-4, y = 1-3) were found in a new region of ionic plastic crystals. In this area, globular cations and anions are assembled by weak interactions. Based on the results of solid-state 1H and 13C nuclear magnetic resonance (NMR) measurements, it was revealed that the ions performed isotropic reorientations in the NEtxMe(4-x)BEt4 crystals (x = 0-4). Additionally, X-ray diffraction (XRD) of these compounds was able to identify the CsCl-type cubic structure. In contrast, the XRD reflections of NEtyPr(4-y)BEt4 (y = 1-3) could be successfully fitted by distorted cubic lattices (trigonal symmetry). The NMR line shapes observed in these compounds were explained by overall molecular motions with large amplitudes (pseudo-isotropic reorientations). Differential scanning calorimetry (DSC) spectra of NEtyPr(4-y)BEt4 (y = 1-3) showed a low entropy change (ΔSmp) of 6-8 J K-1 mol-1 at the melting point. Ionic diffusion was identified by electrical conductivity measurements of NEtxMe(4-x)BEt4 and NEtyPr(4-y)BEt4 (x = 0-4, y = 1-3). In the case of NPr4BEt4 crystals, ionic diffusion was also detected, although complex powder patterns and large ΔSmp values were observed by XRD and DSC measurements, respectively.

  9. Internal dynamics of (C 3N 2H 5) 5Bi 2Cl 11 studied by IINS, 1H NMR and QC methods

    Hołderna-Natkaniec, K.; Natkaniec, I.; Jakubas, R.; Nowak, D.; Medycki, W.

    2008-11-01

    The low temperature inelastic incoherent neutron scattering spectra of pentakis (imidazolium) undecachlorodibismuthate (III) [(C 3N 2H 5) 5Bi 2Cl 11] were discussed versus different models of reference structures obtained by quantum chemical calculations in the energy transfer range up to 1200 cm -1. The second moment of 1H NMR line and spin-lattice relaxation times were employed to study the internal dynamics of imidazolium cation at the ferroelectric-paraelectric phase transition.

  10. A 1 H and 13 C NMR study of 2-methyl-4-N-phenyl amino quinazoline precursors

    2-substituted-4-phenyl amino quinazolines, synthetic intermediates of anti malarial, pesticides, herbicides and also inhibitors of the EGF receptor tyrosine kinase, are potentially useful as chemotherapeutic agents or the treatment of cancer. A few recent papers have described the synthesis and the corresponding biological activity studies of some derivates, and it has also been shown that their biological potency depends upon the substituent electronic properties in the 4-position of the quinazoline ring. Thus, it is expected that the biological activity can also be correlated with their Hydrogen-1 or Carbon-13 NMR chemical shift. This work reports the steps for both hydrogen-1 and carbon-13 NMR chemical shifts assignments for these compounds. Results are presented

  11. 1H, 13C and 15N NMR spectral and X-ray structural studies of 2-arylsulfonylamino-5-chlorobenzophenones

    Six 2-(4-R-phenylsulfonylamino)-5-chlorobenzophenones were prepared and their 1H, 13C and 15N NMR spectra recorded and assigned. The dependence between the chemical shift of the amide proton and Hammett σ substituent constants is of the V type. Substituent effect on the chemical shift of the amide nitrogen atom was found insignificant. X-ray analysis shows that the terminal benzene rings in 2-(4-nitro-phenylsulfonylamino)-5-chlorobenzophenones are located close to each other. They are not, however, parallel, dihedral angle between them being equal to 10.86 deg (MP2/6-31G**//HF/6-31G** ab initio calculations show this to be 20.44 deg). This shows that the mutual orientation of two benzene rings in the molecule of this compound is caused by the π-π stacking. It is additionally reinforced by the intramolecular NH...O=C hydrogen bond. Except the dihedral angle between the benzene rings, X-ray determined structure of 2-(4-nitro-phenylsulfonylamino)-5-chlorobenzophenones is very similar to this optimized by the ab initio calculations. (author)

  12. Silver(I) and copper(I) bis(pyridine-2-carbaldehyde-imine) triflate complexes studied in solution by 1H, 1H-{109Ag}, INEPT 15N and INEPT 109Ag NMR

    Koten, G. van; Stein, G.C. van; Bok, B. de; Taylor, L C; Vrieze, K.; Brevard, C.

    1984-01-01

    The reactions of the neutral pyridine-imine, 6-R-py-2-CH=N-R' (NN'), donor ligands with [M(O{3}SCF{3})] [M = Ag(I) or Cu(I)] yield ionic complexes, consisting of a [M(NN'){2}]}+{ cation and a O{3}SCF{3}}-{ anion. }1{H NMR studies of the complexes which contain the prochiral substituent (R') i-Pr or the chiral (S)-CHMePh show that in the slow exchange limit the metal IB centres have tetrahedral geometries as a result of chelate bonding of the pyridine-imine ligands. The metal IB centres have e...

  13. Crystal struture and 1H n.m.r. conformational studies of diplosporin: a mycotoxin from Diplodia macrospora

    The crystal structure of diplosporin, a mycotoxin produced by Diplodia macrospora, has been determined by single-crystal X-ray diffraction methods. It crystalizes in the space group P212121 with four molecules in the asymetric unit. The secondary hydroxy-group is trans to the ethyl side-chain, and the configuration of the chiral centres, to which these groups are attached, are S and R respectively. The conformation of the solid-state structure is compared with that in chloroform solution, as evidenced by high-field n.m.r. studies

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

    Musio, Roberta; Sciacovelli, Oronzo

    2009-09-01

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

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

    Haddad, Daniel

    2005-01-01

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

  16. 1H High Resolution Magic-Angle Coil Spinning (HR-MACS) - NMR Metabolic Profiling of whole Saccharomyces cervisiae cells: A Demonstrative Study

    Wong, Alan; Boutin, Celine; Aguiar, Pedro

    2014-06-01

    The low sensitivity of Nuclear Magnetic Resonance (NMR) is its prime shortcoming compared to other analytical methods for metabolomic studies. It relies on large sample volume (30-50 µl for HR-MAS) for rich metabolic profiling, hindering high-throughput screening especially when the sample requires a labor-intensive preparation or is a sacred specimen. This is indeed the case for some living organisms. This study evaluates a 1H HR-MAS approach for metabolic profiling of small volume (250 nl) whole bacterial cells, Saccharomyces cervisiae, using an emerging micro-NMR technology: high-resolution magic-angle coil spinning (HR-MACS). As a demonstrative study for whole cells, we perform two independent metabolomics studies identifying the significant metabolites associated with osmotic stress and aging.

  17. 1H High Resolution Magic-Angle Coil Spinning (HR-MACS µNMR Metabolic Profiling of whole Saccharomyces cervisiae cells: A Demonstrative Study

    Alan eWong

    2014-06-01

    Full Text Available The low sensitivity of Nuclear Magnetic Resonance (NMR is its prime shortcoming compared to other analytical methods for metabolomic studies. It relies on large sample volume (30–50 µl for HR-MAS for rich metabolic profiling, hindering high-throughput screening especially when the sample requires a labor-intensive preparation or is a sacred specimen. This is indeed the case for some living organisms. This study evaluates a 1H HR-MAS approach for metabolic profiling of small volume (250 nl whole bacterial cells, Saccharomyces cervisiae, using an emerging micro-NMR technology: high-resolution magic-angle coil spinning (HR-MACS. As a demonstrative study for whole cells, we perform two independent metabolomics studies identifying the significant metabolites associated with osmotic stress and aging.

  18. Determination of the major tautomeric form of the covalently modified adenine in the (+)-CC-1065-DNA adduct by 1H and 15N NMR studies

    (+)-CC-1065 is an extremely potent antitumor antibiotic produced by Streptomyces zelensis. The potent cytotoxic effects of the drug are thought to be due to the formation of a covalent adduct with DNA through N3 of adenine. Although the covalent linkage sites between (+)-CC-1065 and DNA have been determined, the tautomeric form of the covalently modified adenine in the (+)-CC-1065-DNA duplex adduct was not defined. The [6-15N]deoxyadenosine-labeled 12-mer duplex adduct was then studied by 1H and 15N NMR. One-dimensional NOE difference and two-dimensional NOESY 1H NMR experiments on the nonisotopically labeled 12-mer duplex adduct demonstrate that the 6-amino protons of the covalently modified adenine exhibit two signals at 9.19 and 9.08 ppm. Proton NMR experiments on the [6-15N]deoxyadenosine-labeled 12-mer duplex adduct show that the two resonance signals for adenine H6 observed on the nonisotopically labeled duplex adduct were split into doublets by the 15N nucleus with coupling constants of 91.3 Hz for non-hydrogen-bonded and 86.8 Hz for hydrogen-bonded amino protons. The authors conclude that the covalently modified adenine N6 of the (+)-CC-1065-12-mer duplex adduct is predominantly in the doubly protonated form, in which calculations predict that the C6-N6 bond is shortened and the positive charge is delocalized over the entire adenine molecule

  19. 1H High Resolution Magic-Angle Coil Spinning (HR-MACS) µNMR Metabolic Profiling of whole Saccharomyces cervisiae cells: A Demonstrative Study

    AlanWong

    2014-01-01

    The low sensitivity of Nuclear Magnetic Resonance (NMR) is its prime shortcoming compared to other analytical methods for metabolomic studies. It relies on large sample volume (30–50 µl for HR-MAS) for rich metabolic profiling, hindering high-throughput screening especially when the sample requires a labor-intensive preparation or is a sacred specimen. This is indeed the case for some living organisms. This study evaluates a 1H HR-MAS approach for metabolic profiling of small volume (250 nl) ...

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

    Searle, M S; Embrey, K J

    1990-01-01

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

  1. Assay of ascorbic acid in plants tissues, I: 1H and 13C NMR study of the complex between Cu(I) and 2,2'-biquinoline

    The Shieh's method, originally devised for the analysis of ascorbic acid (AsA) in pharmaceutical preparations and based on the reaction of this acid with Cu(I) and 2,2'-biquinoline, was adapted to determine AsA in biological samples and particularly in plant tissues. The proposed assay is compared with some current methods for AsA determination. Moreover the system Cu(I)-biquinoline is studied by 1H and 13C NMR spectroscopy, and a coordination model for the complex is proposed. (author). 12 refs., 4 figs., 2 tabs

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

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

    1997-01-01

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

  3. 1H NMR spectroscopic identification of a glue sniffing biomarker.

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

    2011-06-15

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

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

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

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

  5. 1H NMR Study of Molecular Dynamics of 4-apyH Cation under High Hydrostatic Pressure

    Medycki, W.; Świergiel, J.; Jakubas, R.; Hołderna-Natkaniec, K.

    2006-07-01

    Polycrystalline [4-NH2C5H4NH] SbCl4 and [4-NH2C5H4NH] SbCl6 have been investigated by proton NMR methods between 120 K and 370 K under hydrostatic pressure of 0.1 and 520 MPa. Reduction in the dipolar second moment is interpreted in terms of cation reorientation. Activation energies characterizing the motion increase with increasing pressure.

  6. 1H NMR study of molecular dynamics of 4-apyH cation under high hydrostatic pressure

    Polycrystalline [4-NH2C5H4NH]SbCl4 and [4-NH2C5H4NH]SbCl6 have been investigated by proton NMR methods between 120 and 370 K under hydrostatic pressure of 0.1 and 520 MPa. Reduction in the dipolar second moment is interpreted in terms of cation reorientation. Activation energies characterizing the motion increase with increasing pressure. (author)

  7. Development of a low resolution (1)H NMR spectroscopic technique for the study of matrix mobility in fresh and freeze-thawed hen egg yolk.

    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

  8. Structural and dynamic aspects of binding of prototype lexitropsin to the decadeoxyribonucleotide d(CGCAATTGCC)2 deduced from high-resolution 1H NMR studies

    Structural and dynamic properties of the self-complementary decadeoxyribonucleotide d-(CGCAATTGCC)2 and the interaction between a prototype lexitropsin, or information-reading oligopeptide, and the decadeoxyribonucleotide and are deduced by using high-resolution 1H NMR techniques. The nonexchangeable and imino proton resonances of d(CGCAATTGCG)2 have been completely assigned by two-dimensional NMR studies. The decadeoxyribonucleotide exists as a right-handed B-DNA. In the 1H NMR spectrum of the l:1 complex, the selective chemical shifts and removal of degeneracy of AH2(4), AH2(5), T-CH3(6), and T-CH3(7) due to the anisotropy effects of the heterocyclic moieties of the ligand, and with lesser effects at the flanking base sites C(3) and G(8), locate the drug centrally in the decadeoxyribonucleotide. This conclusion is supported by plots of individual chemical shift changes across the decadeoxyribonucleotide. Strong nuclear Overhauser effects (NOEs) between pyrrol H5 and AH2(5), and weaker NOEs to AH1'(5), TH3'(6), and AH2'(5), firmly locate the ligand in the minor groove. Intraligand NOEs between the adjacent heterocyclic moieties indicate that the lexitropsin is subject to propeller twisting about the N6-C9 bond in both the bound and free forms. Nuclear Overhauser effect spectroscopy (NOESY) and correlated spectroscopy (COSY) experiments also indicate that the removal of degeneracy of the C16 methylene protons upon complexation may arise from restricted rotation about the C15-N9, C15-C16, and C16-C17 bonds. NOE measurements on the decadeoxyribonucleotide in the 1:1 complex confirm it exists as a right-handed helix and belongs to the B family. Alternative mechanisms for this exchange process are considered

  9. 1H NMR and DSC study of temperature induced phase transition in solutions of acrylamide/N-isopropylmethacrylamide copolymers

    Šťastná, J.; Hanyková, L.; Spěváček, Jiří

    Zagreb : Faculty of Chemical Engineering and Technology, University of Zagreb, 2010 - (Volovšek, V.; Bistričić, L.; Šapić, I.). s. 41 ISBN 978-953-6470-52-5. [European Symposium on Polymer Spectroscopy /18./. 19.09.2010-22.09.2010, Zadar] R&D Projects: GA ČR GA202/09/1281 Institutional research plan: CEZ:AV0Z40500505 Keywords : temperature induced phase transition * acrylamide /N-isopropylmethacrylamide statistical copolymers * NMR Subject RIV: CD - Macromolecular Chemistry

  10. 1H NMR spectroscopy-based interventional metabolic phenotyping

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

    2010-01-01

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

  11. Applications of 1H-NMR to Biodiesel Research

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

  12. Design, synthesis and 1H NMR study of C3v-symmetric anion receptors with urethane-NH as recognition group

    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.

  13. A study of the molecular conformations and the vibrational, 1H and 13C NMR spectra of the anticancer drug tamoxifen and triphenylethylene

    Badawi, Hassan M.; Khan, Ibrahim

    2016-08-01

    The structural stability and the vibrational spectra of the anticancer drug tamoxifen and triphenylethylene were investigated by the DFT B3LYP/6-311G (d,p) calculations. Tamoxifen and triphenylethylene were predicted to exist predominantly as non-planar structures. The vibrational frequencies and the 1H and 13C NMR chemical shifts of the low energy structures of tamoxifen and triphenylethylene were computed at the DFT B3LYP level of theory. Complete vibrational assignments were provided by combined theoretical and experimental data of tamoxifen and triphenylethylene. The 1H and 13C NMR spectra of both molecules were interpreted by experimental and DFT calculated chemical shifts of the two molecules. The RMSD between experimental and theoretical 1H and 13C chemical shifts for tamoxifen is 0.29 and 4.72 ppm, whereas for triphenylethylene, it is 0.16 and 2.70 ppm, respectively.

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

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

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

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

    2009-09-14

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

  16. 1H NMR profiling as an approach to differentiate conventionally and organically grown tomatoes.

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

    2014-08-20

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

  17. Application of (1)H NMR-based serum metabolomic studies for monitoring female patients with rheumatoid arthritis.

    Zabek, Adam; Swierkot, Jerzy; Malak, Anna; Zawadzka, Iga; Deja, Stanisław; Bogunia-Kubik, Katarzyna; Mlynarz, Piotr

    2016-01-01

    Rheumatoid arthritis is a chronic autoimmune-based inflammatory disease that leads to progressive joint degeneration, disability, and an increased risk of cardiovascular complications, which is the main cause of mortality in this population of patients. Although several biomarkers are routinely used in the management of rheumatoid arthritis, there is a high demand for novel biomarkers to further improve the early diagnosis of rheumatoid arthritis, stratification of patients, and the prediction of a better response to a specific therapy. In this study, the metabolomics approach was used to provide relevant biomarkers to improve diagnostic accuracy, define prognosis and predict and monitor treatment efficacy. The results indicated that twelve metabolites were important for the discrimination of healthy control and rheumatoid arthritis. Notably, valine, isoleucine, lactate, alanine, creatinine, GPC  APC and histidine relative levels were lower in rheumatoid arthritis, whereas 3-hydroxyisobutyrate, acetate, NAC, acetoacetate and acetone relative levels were higher. Simultaneously, the analysis of the concentration of metabolites in rheumatoid arthritis and 3 months after induction treatment revealed that L1, 3-hydroxyisobutyrate, lysine, L5, acetoacetate, creatine, GPC+APC, histidine and phenylalanine were elevated in RA, whereas leucine, acetate, betaine and formate were lower. Additionally, metabolomics tools were employed to discriminate between patients with different IL-17A genotypes. Metabolomics may provide relevant biomarkers to improve diagnostic accuracy, define prognosis and predict and monitor treatment efficacy in rheumatoid arthritis. PMID:26476882

  18. Study of the gel films of Acetobacter Xylinum cellulose and its modified samples by 1H NMR cryoporometry and small-angle X-ray scattering

    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.

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

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

    2012-11-01

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

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

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

  1. Hydrogen-bond interactions in organically-modified polysiloxane networks studied by 1D and 2D CRAMPS and double-quantum 1H MAS NMR

    Brus, Jiří; Dybal, Jiří

    2002-01-01

    Roč. 35, č. 27 (2002), s. 10038-10047. ISSN 0024-9297 R&D Projects: GA ČR GA203/98/P290; GA AV ČR KSK4050111 Institutional research plan: CEZ:AV0Z4050913 Keywords : Hydrogen bonding * polysiloxane * 1H MAS NMR Subject RIV: CD - Macromolecular Chemistry Impact factor: 3.751, year: 2002

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

    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

  3. A 1H NMR Study of Host/Guest Supramolecular Complexes of a Curcumin Analogue with β-Cyclodextrin and a β-Cyclodextrin-Conjugated Gemini Surfactant.

    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

  4. STUDY ON THE STRUCTURAL CHANGE OF LIGNIN DURING AUTO-CATALYZED ETHANOL-WATER PULPING OF ASPEN BY 1H-NMR

    Jinghui Zhou

    2009-08-01

    Full Text Available This study concerns the structural change of lignin during auto-catalyzed ethanol-water pulping of aspen by 1H-NMR. The results showed that the linkages of alkyl-aryl ether of lignin, such as the α-ether linkages (α-O-4 and the β-ether linkages (β-O-4, were broken and the alkyl part formed carbenium at the Cα and Cβ of the aliphatic branch. Meanwhile, the aryl part of ether accepted one H+ and formed phenol. Because of the electronegative effect originating from the electron cloud of phenyl, partial carbenium of Cβ was rearranged. Due to its ether or hydroxyl linkage, rearranging to Cβ, the Cα was changed into carbenium and formed a new β-O-4 alkyl-aryl ether. The β-O-4 alkyl-aryl ether was not stable and broken further. So the large molecule of lignin was disintegrated into a smaller one and dissolved into ethanol. Finally, the α+ carbenium reformed α-O-4 linkages of ether with phenol.

  5. A Low-temperature 1H NMR Study of H2O and D2O Associated Competitively with Immunoglobulin G in Solution

    Goryunov, A

    2007-01-01

    An approach has been proposed to characterize the competitive association of D2O and to study the heterogeneity of hydration water adsorbed by the protein, immunoglobulin G, using methodology for determining of non-freezing water in mixed H2O-D2O protein solutions by low-temperature 1H NMR technique. Direct data on the numbers of deuteriums adsorbed by immunoglobulin G and isothermals of water (D2O) sorption by the protein for solution hydration conditions were obtained. The preferential binding of D2O as well as the isotopic effect of low D2O concentrations was simply confirmed using this method. The shape of the isothermals, similar to that for polymolecular adsorption, demonstrates relative changes in the fractions of heavy water isotope bound to different groups of protein atoms on decreasing temperature in frozen solution. At -35 deg C the major fractions attached to charged and polar atomic groups appear to be related as 2/3. The adsorption curves indicate the direct relationship of non-freezing water t...

  6. A study of the experimental and theoretical infrared, Raman, 1H and 13C NMR spectra of the biochemicals valeric and valproic acids

    Badawi, Hassan M.; Förner, Wolfgang; Ali, Shaikh A.

    2014-10-01

    The structural stability, vibrational, 1H and 13C NMR spectra of valeric and valproic acids were investigated by the B3LYP calculations with the 6-311G** basis set. Valeric acid is predicted to exist predominantly in the planar cis form (80% abundance). Valproic acid is predicted to have an equilibrium mixture of 68% gauche-1 and 32% gauche-2 structures at 298.15 K. The spectral feature of the Osbnd H stretching mode in the infrared spectra of both acids suggests the presence of strong H-bonding in the condensed phase of valeric acid and weak H-bonding in the case of valproic acid. The harmonic and anharmonic vibrational wavenumbers were computed at the B3LYP level of theory and tentative vibrational assignments were provided on the basis of combined theoretical and experimental infrared and Raman data of the molecules. Not all of the calculated anharmonic wavenumbers showed a consistent trend with the observed wavenumbers. The 1H and 13C NMR spectra of both acids were interpreted by experimental and DFT calculated chemical shifts of the two acids. The RMSD between experimental and theoretical 1H and 13C chemical shifts for valeric acid is 1.8 and 3.8 ppm, whereas for valproic acid, it is 1.4 and 4.5 ppm, respectively.

  7. 2H and 13C tracer studies of ethanol metabolism by Fourier transform 13C[2H, 1H] NMR difference spectroscopy

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

  8. 1H NMR based metabolic profiling in the evaluation of Japanese green tea quality.

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

    2007-11-14

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

  9. FT-IR, dispersive Raman, NMR, DFT and antimicrobial activity studies on 2-(Thiophen-2-yl)-1H-benzo[d]imidazole.

    Unal, Arslan; Eren, Bilge

    2013-10-01

    2-(Thiophen-2-yl)-1H-benzo[d]imidazole (TBI) was synthesized under microwave conditions and was characterized by FT-IR, dispersive Raman, (1)H-, (13)C-, DEPT-, HETCOR-NMR spectroscopies and density functional theory (DFT) computations. The FT-IR and dispersive Raman spectra of TBI were recorded in the regions 4000-400 cm(-1) and 4000-100 cm(-1). The experimental vibrational spectra were interpreted with the help of normal coordinate analysis based on DFT/B3LYP/6-311++G(d,p) theory level for the more stable tautomeric form (Tautomer 1). The complete vibrational assignments were performed on the basis of the potential energy distribution (PED) of the vibrational modes, calculated with scaled quantum mechanical (SQM) method. A satisfactory consistency between the experimental and theoretical findings was obtained. The frontier molecular orbitals (FMOs), atomic charges and NMR shifts of the two stable tautomeric forms were also obtained at the same theory level without any symmetry restrictions. In addition, the title compound was screened for its antimicrobial activity and was found to be exhibit antifungal and antibacterial effects. PMID:23756262

  10. Comparative molecular field analysis and comparative molecular similarity index analysis studies on 1H NMR chemical shift of NH group of diaryl triazene derivatives.

    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

  11. Two- and three-dimensional sup 1 H NMR studies of a wheat phospholipid transfer protein: Sequential resonance assignments and secondary structure

    Simorre, J.P.; Caille, A. (Centre National de la Recherche Scientifique, Orleans (France)); Marion, D. (Laboratoire de Resonance Magnetique en Biologie et Medecine, Grenoble (France)); Marion, D. (INRA, Nantes (France)); Ptak, M. (Centre National de la Recherche Scientifique, Orleans (France) Univ. d' Orleans (France))

    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.

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

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

    1995-02-01

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

  13. Conformation and dynamics of polyoxyethylene lauryl ether (Brij-35) chains in aqueous micellar solution studied by 2D NOESY and 1H NMR relaxation

    GAO; Hongchang(高红昌); FANG; Xiaowen(方晓雯); MAO; Shizhen(毛诗珍); YUAN; Hanzhen(袁汉珍); ZHAO; Sui(赵濉); CHENG; Gongzhen(程功臻); YU; Jiayong(俞稼镛); DU; Youru(杜有如)

    2002-01-01

    Spin-lattice relaxation time, spin-spin relaxation time and two-dimensional nuclear Overhauser enhancement spectroscopy (2D NOESY) experiments of polyoxyethylene lauryl ether (Brij-35) micelles in aqueous solutions at a concentration of 100 times the critical micellar concentration (cmc) give direct evidence that the hydrophilic polyoxyethylene chains, staying in the exterior of the micellar core, are coiled, bent and aligned around the micellar core with a certain number of water molecules included. This hydrophilic layer is in contact with the solvent, water, keeping the micellar solution stable. 1H NMR relaxation time measurements show that the first oxyethylene group next to the alkyl chain participates in the formation of the surface area of the micellar core. The motion of the hydrophilic polyoxyethylene chains is less restricted as compared with the hydrophobic alkyl chains.

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

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

    2012-07-01

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

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

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

  16. 基于1H NMR谱的给药赭石大鼠血清代谢组学研究%A1H NMR-Based Metabonomic Study on the Serum of Haematitum-Treated Rats

    魏莹; 章文军; 薛蓉; 李晓晶; 裴奉奎

    2015-01-01

    Wistar rats were intragastrically administered with different doses (0, 2, 5 g/kg body weight) of haematitum.1H NMR-based metabonomic techniques were used to analyze the metabolic profiles of the serum samples collected from the treated rats. Significant treatment-related changes were observed for the levels of-hydroxybutyate, acetate, acetone, choline, glycerophosphorylcholine, glucose, lactate, low density lipoprotein, very low density lipoprotein and lipids. Such biochemical changes indicated that haematitum treatment at the dose of 2 or 5 g/kg body weight gave rise to reactive oxygen species (ROS) and caused peroxidation damage. It is concluded that haematitum treatment affects glucose, lipid and energy metabolism in rats.%基于1H NMR的代谢组学方法对灌胃给药赭石的成年Wistar大鼠血清进行分析,运用主成分分析模式识别方法对所得数据进行处理,并对给药大鼠血清进行生化指标检测.研究结果表明,大鼠体内-羟异丁酸、乙酸、丙酮、胆碱、甘油磷脂酰胆碱、葡萄糖、乳酸、低密度脂蛋白、极低密度脂蛋白和脂质等内源性代谢物浓度发生明显变化,可作为赭石的特征代谢物.2 g/kg和5 g/kg体重剂量赭石使大鼠机体产生大量活性氧化物(ROS),造成过氧化损伤,导致能量代谢和糖代谢紊乱,糖酵解反应增强,并且对肝功能造成了影响.

  17. Polypeptide chain fold of human transforming growth factor α analogous to those of mouse and human epidermal growth factors as studied by two-dimensional 1H NMR

    The 1H NMR spectrum of human transforming growth factor α (TGF-α) was analyzed almost completely by the sequential assignment method using two-dimensional NMR techniques. On the basis of the nearly complete sequence-specific resonance assignment, secondary and tertiary structures of human TGF-α in solution (pH 4.9, 28 degree C) were determined to satisfy the upper limits of proton-proton distances derived from nuclear Overhauser effect experiments. Although human TGF-α and mouse epidermal growth factor (EGF) share 27% homology in amino acid sequence, the backbone chain folds in the two growth factors are quite similar. The structure and function of TGF-α is well characterized by the mitten model previously proposed for mouse EGF. The gross shape of the TGF-α molecule resembles a mitten. TGF-α interacts with the receptor as a mitten would grasp an object. However, there is an appreciable structural difference between the two growth factors in the back of the mitten that is formed by the N-terminal polypeptide segment. This is consistent with the evidence that the backs of these molecules are not involved in the receptor binding

  18. Crystal structure and theoretical study of IR and 1H and 13C NMR spectra of cordatin, a natural product with antiulcerogenic activity

    Brasil, Davi S. B.; Alves, Cláudio N.; Guilhon, Giselle M. S. P.; Muller, Adolfo H.; Secco, Ricardo De S.; Peris, Gabriel; Llusar, Rosa

    Cordatin is a furan diterpenoid with a clerodane skeleton isolated from Croton palanostigma Klotzsch (Euphorbiaceae). This natural product shows significant antiulcerogenic activity, similar to cimetidine (Tagamet®), a compound used for the treatment of peptic ulcers. The crystal structure of cordatin was obtained by X-ray diffraction and its geometrical parameters were compared with theoretical calculations at the B3LYP theory level. The IR and NMR (1H and 13C chemical shifts and coupling constants) spectra were obtained and compared with the theoretical calculations. The B3LYP theory level, with the 6-31G(d,p) and 6-311G(d,p) basis set, provided IR absorption values close to the experimental data. Moreover, theoretical NMR parameters obtained in both gas phase and chloroform solvent at the B3PW91/DGDZVP, B3LYP/6-311+G(2d,p), and B3PW91/6-311+G(2d,p) levels showed good correlations with the experimental results.

  19. X-ray and 1H-NMR spectroscopic studies of the structures and conformations of the new nootropic agents RU-35929, RU-47010 and RU-35965

    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.

  20. Structural and dynamic differences between normal and transforming N-ras gene products: A 31P and isotope-edited 1H NMR study

    [15B]Glycine was biosynthetically incorporated into normal cellular N-ras p21 and a position 12 transforming mutant, in order to produce p21 proteins containing several site-specific NMR probes at or near activating positions in the guanine nucleotide binding domain. The authors have previously assigned all five glycine resonances located in loops directly involved in binding of guanosine diphosphate in the wild-type p21 protein. In this report, the corresponding glycine resonances in the p21 mutant have been assigned, and spectral differences between normal and mutant p21-guanosine diphosphate (p21-GDP) complexes have been investigated. The combined 1H15N and 31P NMR results show that substitution of aspartate for glycine-12 produces perturbations in the phosphoryl binding domain, near the point of the mutation. Although many of the remaining glycines were unaffected, spectral differences were also observed outside the GDP binding domain. Two of the five active-site glycines in wild-type p21-GDP have very slow amide proton exchange rates with water. The active=site glycine are located in solvent-exposed loops, so their apparent solvent inaccessibility may result from strong hydrogen bond formation between glycine amide protons and bound guanine diphosphate and/or other nearby groups in p21

  1. 1H NMR metabolomic study of auxotrophic starvation in yeast using Multivariate Curve Resolution-Alternating Least Squares for Pathway Analysis

    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

  2. (1)H NMR metabolomic study of auxotrophic starvation in yeast using Multivariate Curve Resolution-Alternating Least Squares for Pathway Analysis.

    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

  3. 1H NMR study of 4-aminopyrimidine coordinated to the paramagnetic undecatung-stocobalto(II)silicate anion: rates of internal rotation of the amine group

    1H NMR spectrum of a DMF-d7 solution containing 4-aminopyrimidine and [SiW11CoIIO39]6- (SiW11Co) shows separate peaks from two linkage isomers, a and b, in which N(1) and N(3) of the pyrimidine ring are coordinated to SiW11Co, respectively. The signal from the amine group in the isomer a exhibits temperature dependence that is characteristic of a two-site exchange problem. Rates of internal rotation of the amine group were determined by simulating the NMR spectra at 5-35.deg.C. The amine group of free 4-aminopyrimidine also shows temperature-dependent spectra at lower temperatures; rates of internal rotation at (-25)-25.deg.C were determined. The internal rotation of the amine group in the complex is much slower than that for free 4-aminopyrimidine, indicating that π-character of the C-N bond increases on coordination to SiW11Co. The amine group in the isomer b does not show such behavior. It is probable that hydrogen bonding between N-H and a bridging oxygen atom of SiW11Co prevents it from rotating at low temperatures

  4. Interaction Study of an Amorphous Solid Dispersion of Cyclosporin A in Poly-Alpha-Cyclodextrin with Model Membranes by 1H-, 2H-, 31P-NMR and Electron Spin Resonance

    Jean-Claude Debouzy

    2014-01-01

    Full Text Available The properties of an amorphous solid dispersion of cyclosporine A (ASD prepared with the copolymer alpha cyclodextrin (POLYA and cyclosporine A (CYSP were investigated by 1H-NMR in solution and its membrane interactions were studied by 1H-NMR in small unilamellar vesicles and by 31P 2H NMR in phospholipidic dispersions of DMPC (dimyristoylphosphatidylcholine in comparison with those of POLYA and CYSP alone. 1H-NMR chemical shift variations showed that CYSP really interacts with POLYA, with possible adduct formation, dispersion in the solid matrix of the POLYA, and also complex formation. A coarse approach to the latter mechanism was tested using the continuous variations method, indicating an apparent 1 : 1 stoichiometry. Calculations gave an apparent association constant of log Ka = 4.5. A study of the interactions with phospholipidic dispersions of DMPC showed that only limited interactions occurred at the polar head group level (31P. Conversely, by comparison with the expected chain rigidification induced by CYSP, POLYA induced an increase in the fluidity of the layer while ASD formation led to these effects almost being overcome at 298 K. At higher temperature, while the effect of CYSP seems to vanish, a resulting global increase in chain fluidity was found in the presence of ASD.

  5. 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.

    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

  6. HPLC/1H NMR spectroscopic studies of the reactive alpha-1-O-acyl isomer formed during acyl migration of S-naproxen beta-1-O-acyl glucuronide.

    Corcoran, O; Mortensen, R W; Hansen, S H; Troke, J; Nicholson, J K

    2001-10-01

    A widely held view in drug metabolism and pharmacokinetic studies is that the initial 1-isomer to 2-isomer step in the intramolecular acyl migration of drug ester glucuronides is irreversible, and that alpha-1-O-acyl isomers do not occur under physiological conditions. We investigated this hypothesis using high-performance liquid chromatography directly coupled to proton nuclear magnetic resonance spectroscopy (HPLC/1H NMR) and mass spectrometry (LC/MS) to probe the migration reactions of S-naproxen beta-1-O-acyl glucuronide, in phosphate buffer at pH 7.4, 37 degrees C. We report the first direct observation of the alpha-1-O-acyl isomer of a drug ester glucuronide (S-naproxen) formed in a biosystem via the facile acyl migration of the corresponding pure beta-1-O-acyl glucuronide. The unequivocal identification of the reactive product was achieved using stopped-flow one-dimensional HPLC/1H NMR and two-dimensional 1H-1H total correlation spectroscopy (1H-1H TOCSY). Parallel LC/ion-trap mass spectrometry yielded the confirmatory glucuronide masses. Moreover, "dynamic" stopped-flow HPLC/1H NMR experiments revealed transacylation of the isolated alpha-1-O-acyl isomer to a mixture of alpha/beta-2-O-acyl isomers; the reverse reaction from the isolated alpha/beta-2-O-acyl isomers to the alpha-1-O-acyl isomer was also clearly demonstrated. This application of "dynamic" stopped-flow HPLC/1H NMR allows key kinetic data to be obtained on a reactive metabolite that would otherwise be difficult to follow by conventional HPLC and NMR methods where sample preparation and off-line separations are necessary. These data challenge the widely held view that the alpha-1-O-acyl isomers of drug ester glucuronides do not occur under physiological conditions. Furthermore, the similar formation of alpha-1-O-acyl isomers from zomepirac and diflunisal beta-1-O-acyl glucuronides has recently been confirmed (Corcoran et al., unpublished results). Such reactions are also likely to be widespread

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

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

  8. sup(1)H, sup(13)C and sup(17)O NMR studies of cumene hydroperoxide coordination to Cr(AA)sub(3)

    The mechanism of the catalytic decomposition of hydroperoxides by tris-chelates of transition metals was studied by means of NMR. It was established that the outer sphere coordination of cumene hydroperoxide to tris-acetylacetonate of Cr(III) (Cr(AA)sub(3)) is due to both the formation of hydrogen bonds between hydroxyl proton and chelate oxygen atoms and the π-π-interactions between the aromatic ring and chelate π-system. (author)

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

    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 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.

  10. 1H, 13C and 31P-NMR spectroscopic study of glucose metabolism of muscle larva Trichinella spiralis (U.S.A. strain), and the effects of the end-products on the host (mouse)

    1H- and 13C-nuclear magnetic resonance (NMR) spectroscopy was used to identify and quantitate metabolites excreted by muscle larva Trichinella spiralis maintained aerobically in the presence of D- (13C6) glucose and (1, 1'-13C2) succinate. End-products of glucose metabolism studied by 1H-NMR were lactate, acetate, succinate, proionate, n-valerate and alanine, at the molar ratio of 1:2:1:0.6:0.5:0.6. 13C-NMR measurement proved that all the products originated from the glucose in the medium via the phosphoenolpyruvate carboxykinase-succinate pathway and the tricarboxylic acid cycle. In vivo 31P-NMR spectra were also taken by the surface coil method from the leg muscle of mice which had been infected with T. spiralis. Intracelluar pH and relative amount of ATP in the leg muscle of the infected mice were found to decrease significantly as compared with that of control mice. (author)

  11. (1) H-NMR relaxometric studies of interaction between apoptosis specific MRI paramagnetic contrast agents and micellar models of apoptotic cells.

    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

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

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

    2014-01-01

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

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

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

    2010-08-01

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

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

    Rousseau, Réjane

    2011-01-01

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

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

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

    2015-04-15

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

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

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

  17. Theoretical predictions of the two-dimensional solid-state NMR spectra: a case study of the 13C-1H correlations in metergoline

    Czernek, Jiří; Brus, Jiří

    2013-01-01

    Roč. 586, 24 October (2013), s. 56-60. ISSN 0009-2614 Institutional support: RVO:61389013 Keywords : NMR * shielding * metergoline Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 1.991, year: 2013

  18. Electroacupuncture at Acupoints Reverses Plasma Glutamate, Lipid, and LDL/VLDL in an Acute Migraine Rat Model: A1H NMR-Based Metabolomic Study

    Zishan Gao

    2014-01-01

    Full Text Available Background. The objective of this study was to identify potential biomarkers of electroacupuncture (EA on relieving acute migraine through metabolomic study. Methods. EA treatments were performed on both acupoints and nonacupoints on the nitroglycerin (NTG-induced migraine rat model. NMR experiments and multivariate analysis were used for metabolomic analysis. Results. The number of head-scratching, the main ethology index of migraine rat model, was significantly increased P<0.01 after NTG injection. The plasma metabolic profile of model group was distinct from that of the control group. Glutamate was significantly increased P<0.01, whereas lipids were significantly decreased P<0.01 in model rats. After EA at acupoints, the metabolic profile of model rats was normalized, with decreased glutamate P<0.05 and increased lipids P<0.01. In contrast, EA at nonacupoints did not restore the metabolic profile, but with six metabolites significantly different from acupoints group. Interestingly, the number of head-scratching and glutamate level were significantly decreased P<0.05 after receiving EA at both acupoints and nonacupoints. Conclusions. EA at acupoints may relieve acute migraine by restoring the plasma metabolic profile and plasma glutamate, while EA at nonacupoints may modestly relieve acute migraine by decreasing plasma glutamate.

  19. 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.

    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

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

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

    2014-10-01

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

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

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

    2009-07-01

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

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

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

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

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

    1990-03-27

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

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

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

  5. 1H to 13C Energy Transfer in Solid State NMR Spectroscopy of Natural Organic Systems

    Berns, Anne E.; Conte, Pellegrino

    2010-05-01

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

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

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

    2007-01-01

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

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

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

  8. 1H, 13C and 15N NMR assignments of phenazopyridine derivatives.

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

    2005-03-01

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

  9. 1H NMR investigation of self-association of vanillin in aqueous solution

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

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

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

    2009-08-01

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

  11. 1H NMR investigation of self-association of vanillin in aqueous solution

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

    2009-08-01

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

  12. Synthesis and multinuclear (1H, 13C, 31P, 119Sn) NMR study of trimethyland; triphenyl-tin (IV) with cyclic dithiophosphate ligands

    Patricia García y García; Marcela López Cardoso; María del Carmen Pérez Redondo; Patricia Martínez Salas; Ave María Cotero Villegas; Raymundo Cea Olivares

    2004-01-01

    En este trabajo se informa la síntesis y caracterización; estructural de seis nuevos ditiofosfatos de trimetil- y trifenil-estaño (IV).; Los compuestos 1-6 fueron caracterizados por IR, EM IE y RMN multinuclear,; (1H, 13C, 19P y 119Sn). Los seis compuestos manifiestan un; comportamiento monomérico, con una penta-coordinación del átomo de; estaño y un comportamiento monometálico biconectivo de los ligantes.; Los compuestos 1-4 presentan en solución una rápida interconversión;...

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

    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. Ehrlich and sarcoma 180 tumour characterisation and early detection by {sup 1}H NMR-based metabonomics of mice serum

    Grandizoli, Caroline W.P. da S.; Simonelli, Fabio; Nagata, Noemi; Barison, Andersson, E-mail: andernmr@ufpr.br [Universidade Federal do Parana (UFPR), Curitiba, PR (Brazil). Dept. de Quimica; Carrenho, Luise Z.B.; Francisco, Thais M.G. de; Campos, Francinete R. [Universidade Federal do Parana (UFPR), Curitiba, PR (Brazil). Dept. de Farmacia; Santana Filho, Arquimedes P. de; Sassaki, Guilherme L. [Universidade Federal do Parana (UFPR), Curitiba, PR (Brazil). Dept. de Bioquimica; Kreuger, Maria R.O. [Universidade do Vale do Itajai (UNIVALI), (Brazil). Centro de Ciencias da Saude

    2014-05-15

    The success of cancer treatment is directly related to early detection before symptoms emerge, although nowadays few cancers can be detected early. In this sense, {sup 1}H nuclear magnetic resonance ({sup 1}H NMR)-based metabonomics was used to identify metabolic changes in biofluid as a consequence of tumours growing in mice. Through partial least squares discriminant analysis (PLS-DA) analysis of {sup 1}H NMR spectra from serum samples it was possible to diagnose Ehrlich ascites and Sarcoma 180 tumours five and ten days after cell inoculation, respectively. Lipids, lipoproteins and lactate were the main biomarkers at onset as well as in the progress of carcinogenic process. Thus, NMR-based metabonomics can be a valuable tool to study the effects of tumour establishment on the chemical composition of biofluids. (author)

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

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

    2009-08-01

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

  16. A 1H NMR pulse gradient spin-echo (PGSE) study of the mass transport of dimethyl oxalate and ethylene glycol: new fuels for the DOFC

    Direct oxidation fuel cell (DOFC) based on proton conducting membranes (PCM's) represents a promising energy technology, with the vast majority of efforts devoted to methanol as the fuel. The most commonly used PCM is Nafion. However, because of high production cost, high fuel crossover, and sensitivity to metal-ion impurities, alternative materials are being developed. Methanol presents several limitations including low boiling point (∼65 deg. C), and reduced cell efficiency due to fuel crossover. We present here a measure of the mass transport represented by the self-diffusion coefficients (D) of methanol, and two alternative fuels--ethylene glycol (EG) and dimethyl oxalate (DMO) in new low-cost nanoporous (NP) PCM's. The NP-PCM's are based on commercial poly(vinylidene fluoride), with variable pore size determined by the addition of nanoscale SiO2 or TiO2 particles. Proton NMR pulsed gradient spin-echo (PGSE) self-diffusion measurements were conducted on aqueous solutions of 2 M fuel in 3 M H2SO4 and also on five NP-PCM equilibrated in the aqueous solutions over the temperature range of 30-90 deg. C. Here the fuel molecular mobility is indicated by the D values of the methyl and methylene peaks. Results indicate that both DMO and EG solutions have lower fuel molecular mobility than methanol. Results for the various NP-PCM also reveal reduced fuel permeability for DMO and EG compared with methanol

  17. Ethanol contamination of cerebrospinal fluid during standardized sampling and its effect on 1H-NMR metabolomics

    van der Sar, Sonia A.; Zielman, Ronald; Terwindt, Gisela M; van den Maagdenberg, Arn M.J.M.; Deelder, André M; Mayboroda, Oleg A; Meissner, Axel; Ferrari, Michel D.

    2015-01-01

    Standardization of body fluid sampling, processing and storage procedures is pivotal to ensure data quality in metabolomics studies. Yet, despite strict adherence to standard sampling guidelines, we detected variable levels of ethanol in the 1H-NMR spectra of human cerebrospinal fluid (CSF) samples (range 9.2 × 10−3–10.0 mM). The presence of ethanol in all samples and the wide range of concentrations clearly indicated contamination of the samples of some sort, which affected the 1H-NMR spectr...

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

    Fischer, D.

    1990-09-21

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

  19. Phase diagram of soybean phosphatidylcholine-diacylglycerol-water studied by x-ray diffraction and 31P- and pulsed field gradient 1H-NMR: evidence for reversed micelles in the cubic phase.

    Orädd, G; Lindblom, G; Fontell, K; Ljusberg-Wahren, H

    1995-05-01

    The phase equilibria of the system soybean phosphatidylcholine, diacylglycerol, and water has been determined using a combination of classical methods together with x-ray diffraction and NMR techniques. In particular, the extent of the phase regions of the lamellar, the reversed hexagonal, and the cubic phases have been determined. By pulsed field gradient 1H-NMR, the diffusion coefficients of all three components in a cubic phase composed of soybean phosphatidylcholine, diacylglycerol, and heavy water have been determined at 25 and 59 degrees C and also for the corresponding cubic phase composed of the chemically more well defined synthetic components 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC), 1,2-dioleoylglycerol (DOG), and heavy water. The extension of the phase region of the cubic phase did not seem to change appreciably for the two ternary systems studied. The translational diffusion coefficient of DOPC in this cubic phase is more than an order of magnitude smaller (3 x 10(-13) m2 s-1, 59 degrees C) than the lateral diffusion coefficient of DOPC in an oriented lipid bilayer (5 x 10(-12) m2 s-1, 35 degrees C), whereas the diffusion coefficients of water and DOG were found to be about two orders of magnitude larger than DOPC at 59 degrees C. It is concluded that the cubic phase is built built up of closed reversed micelles in accordance with the suggestion from previous x-ray diffraction studies. PMID:7612827

  20. 1 H and 13 C NMR of phenyl barbiturilidene

    The condensation of barbituric acids with aromatic aldehydes gives the phenyl barbiturilidenes, which are studied as intermediary compounds in the synthesis of new heterocyclic compounds for pharmaceutical use. One of the most characteristic reactions of these compounds is the Michael type addition reaction, in the exocyclic carbon-carbon double binding. The reaction with 2,4-di nitrophenyl hydrazine reaction is been used as a test of this type of reactivity, which supplies the respective hydrazone and barbituric acid. In this work, preliminary studies have been performed for establishing correlations between the Brown parameter (σ+), the chemical shifts (δ) of the barbiturilidene atoms involved in the reaction, and their reactivities

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

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

    2007-06-06

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

  2. 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

    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.

  3. 1H-NMR-based metabolomic profiling of CSF in early amyotrophic lateral sclerosis.

    Hélène Blasco

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

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

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

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

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

    2009-07-15

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

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

    Spraul Manfred

    2015-01-01

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

  7. Ethanol contamination of cerebrospinal fluid during standardized sampling and its effect on (1)H-NMR metabolomics.

    van der Sar, Sonia A; Zielman, Ronald; Terwindt, Gisela M; van den Maagdenberg, Arn M J M; Deelder, André M; Mayboroda, Oleg A; Meissner, Axel; Ferrari, Michel D

    2015-06-01

    Standardization of body fluid sampling, processing and storage procedures is pivotal to ensure data quality in metabolomics studies. Yet, despite strict adherence to standard sampling guidelines, we detected variable levels of ethanol in the (1)H-NMR spectra of human cerebrospinal fluid (CSF) samples (range 9.2 × 10(-3)-10.0 mM). The presence of ethanol in all samples and the wide range of concentrations clearly indicated contamination of the samples of some sort, which affected the (1)H-NMR spectra quality and the interpretation. To determine where in the sampling protocol the ethanol contamination occurs, we performed a CSF sampling protocol simulation with 0.9 % NaCl (saline) instead of CSF and detected ethanol in all simulation samples. Ethanol diffusion through air during sampling and preparation stages appeared the only logical explanation. With a bench study, we showed that ethanol easily diffuses into ex vivo CSF samples via air transmission. Ethanol originated from routinely used skin disinfectants containing ethanol and from laboratory procedures. Ethanol affected the CSF sample matrix at concentrations above ~9.4 mM and obscured a significant part of the (1)H-NMR spectrum. CSF sample preparation for (1)H-NMR-based metabolomics analyses should therefore be carried out in a well-ventilated atmosphere with laminar flow, and use of ethanol should be avoided. PMID:25935669

  8. DFT/PCM, QTAIM, 1H NMR conformational studies and QSAR modeling of thirty-two anti-Leishmania amazonensis Morita-Baylis-Hillman Adducts

    Filho, Edilson B. A.; Moraes, Ingrid A.; Weber, Karen C.; Rocha, Gerd B.; Vasconcellos, Mário L. A. A.

    2012-08-01

    Morita-Baylis-Hillman Adducts (MBHA) has been recently synthesized and bio-evaluated by our research group against Leishmania amazonensis, parasite that causes cutaneous and mucocutaneous leishmaniasis. We present here a theoretical conformational study of thirty-two leismanicidal MBHA by B3LYP/6-31+g(d) calculations with Polarized Continuum Model (PCM) to simulate water influence. Intramolecular Hydrogen Bonds (IHBs) indicated to control the most conformational preferences of MBHA. Quantum Theory Atoms in Molecules (QTAIM) calculations were able to characterize these interactions at Bond Critical Point level. Compounds presenting an unusual seven member IHB between NO2 group and hydroxyl moiety, supported by experimental spectroscopic data, showed a considerable improvement of biological activity (lower IC50 values). These results are in accordance to redox NO2 mechanism of action. Based on structural observations, some molecular descriptors were calculated and submitted to Quantitative Structure-Activity Relationship (QSAR) studies through the PLS Regression Method. These studies provided a model with good validation parameters values (R2 = 0.71, Q2 = 0.61 and Qext2 = 0.92).

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

    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. Effect of rootstock on the scion of Hevea brasiliensis through metabolic analysis of latex samples by 1H NMR

    Eduardo Sanches Pereira do Nascimento

    2011-01-01

    Full Text Available In this study, the effect of rootstock on grafting through metabolomic analysis of latex (Hevea brasiliensis samples was verified by 1H nuclear magnetic resonance (NMR and multivariate data analysis. Sixteen metabolites present in the latex cytosol were characterized by NMR. PCA analysis showed that the latex samples of the RR and GR groups can be differentiated. The GR group samples present a metabolic profile similar to the RR group samples, while the RG group is in an intermediate position between RR and GG groups. Sucrose and formate contributed greatly to the separation obtained by PCA, presenting a good correlation between the results. 1H NMR was an efficient technique to differentiate latex samples from different types of rootstocks and grafting and in the future could be used to predict rubber production by latex analysis.

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

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

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

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

    2013-10-14

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

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

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

    2009-01-01

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

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

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

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

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

    2009-12-01

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

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

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

    2012-07-01

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

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

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

    2005-01-01

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

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

    Ghosh Soumita

    2011-11-01

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

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

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

    2016-01-01

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

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

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

    1999-10-01

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

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

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

    2015-10-14

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

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

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

    2010-10-13

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

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

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

  4. 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).

    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

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

    Defernez, Marianne; Colquhoun, Ian J

    2003-03-01

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

  6. Spectroscopic (FT-IR, FT-Raman, 1H- and 13C-NMR, Theoretical and Microbiological Study of trans o-Coumaric Acid and Alkali Metal o-Coumarates

    Małgorzata Kowczyk-Sadowy

    2015-02-01

    Full Text Available This work is a continuation of research on a correlation between the molecular structure and electronic charge distribution of phenolic compounds and their biological activity. The influence of lithium, sodium, potassium, rubidium and cesium cations on the electronic system of trans o-coumaric (2-hydroxy-cinnamic acid was studied. We investigated the relationship between the molecular structure of the tested compounds and their antimicrobial activity. Complementary molecular spectroscopic techniques such as infrared (FT-IR, Raman (FT-Raman, ultraviolet-visible (UV-VIS and nuclear magnetic resonance (1H- and 13C-NMR were applied. Structures of the molecules were optimized and their structural characteristics were calculated by the density functional theory (DFT using the B3LYP method with 6-311++G** as a basis set. Geometric and magnetic aromaticity indices, atomic charges, dipole moments and energies were also calculated. Theoretical parameters were compared to the experimental characteristics of investigated compounds. Correlations between certain vibrational bands and some metal parameters, such as electronegativity, ionization energy, atomic and ionic radius, were found. The microbial activity of studied compounds was tested against Escherichia coli, Bacillus subtilis, Pseudomonas aeruginosa, Staphylococcus aureus, Proteus vulgaris and Candida albicans.

  7. Spectroscopic (FT-IR, FT-Raman, 1H- and 13C-NMR), theoretical and microbiological study of trans o-coumaric acid and alkali metal o-coumarates.

    Kowczyk-Sadowy, Małgorzata; Świsłocka, Renata; Lewandowska, Hanna; Piekut, Jolanta; Lewandowski, Włodzimierz

    2015-01-01

    This work is a continuation of research on a correlation between the molecular structure and electronic charge distribution of phenolic compounds and their biological activity. The influence of lithium, sodium, potassium, rubidium and cesium cations on the electronic system of trans o-coumaric (2-hydroxy-cinnamic) acid was studied. We investigated the relationship between the molecular structure of the tested compounds and their antimicrobial activity. Complementary molecular spectroscopic techniques such as infrared (FT-IR), Raman (FT-Raman), ultraviolet-visible (UV-VIS) and nuclear magnetic resonance (1H- and 13C-NMR) were applied. Structures of the molecules were optimized and their structural characteristics were calculated by the density functional theory (DFT) using the B3LYP method with 6-311++G** as a basis set. Geometric and magnetic aromaticity indices, atomic charges, dipole moments and energies were also calculated. Theoretical parameters were compared to the experimental characteristics of investigated compounds. Correlations between certain vibrational bands and some metal parameters, such as electronegativity, ionization energy, atomic and ionic radius, were found. The microbial activity of studied compounds was tested against Escherichia coli, Bacillus subtilis, Pseudomonas aeruginosa, Staphylococcus aureus, Proteus vulgaris and Candida albicans. PMID:25689641

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

    Jacob, Daniel; Deborde, Catherine; Moing, Annick

    2013-06-01

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

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

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

    2014-10-01

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

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

    Yang, Donghan

    2016-01-01

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

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

    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

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

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

    2016-08-01

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

  13. Temperature {sup 1}H, {sup 13}C, {sup 15}N NMR and CP/MAS {sup 15}N NMR spectra of benzotriazole derivatives - prototropic tautomerism; Widma temperaturowe {sup 1}H, {sup 13}C, {sup 15}N NMR oraz CP/MAS {sup 15}N NMR pochodnych benzotriazolu - tautomeria prototropowa

    Wiench, J.W.; Stefaniak, L. [Inst. Chemii Organicznej, Polska Akademia Nauk, Warsaw (Poland)

    1994-12-31

    The prototropic tautomerism in benzotriazole derivatives solutions has been investigated in different temperatures by means of {sup 1}H, {sup 13}C and {sup 15}N NMR and {sup 15}N CP/MAS NMR spectra. The ratio of different tautomeric forms and kinetics of proton exchange have been measured for the systems studied on the base of observed spectroscopic factors. 5 refs, 2 figs, 3 tabs.

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

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

  15. 1H NMR study of 2-deoxy-D-arabino-hexopyranose (2-deoxy-glucopyranose), 2-deoxy-D-lyxo-hexopyranose (2-deoxy-galactopyranose) and 2'-deoxy lactose

    Complete analyses of the 1H n.m.r. spectra at 300 MHz of D2O solutions of 2-deoxy-D-arabino-hexopyranose, 2-deoxy-D-lyxo-hexopyranose and 2'-deoxy lactose. Chemical shifts in the deoxy monosaccharides and in 2'-deoxy lactose. Chemical shifts in the deoxy monosaccharides and in 2'-deoxy lactose are compared with those previously obtained in the parent aldeohexopyranoses, glucobioses and D-galactopyranosol-D-glucoses. Increment values are suggested in order to predict chemical shifts in 2-deoxy derivatives from the well known rules for aldohexopyranoses. (author)

  16. 1H NMR spectroscopic determination of deterioration marker compounds in fats and oils

    Skiera, Christina

    2013-01-01

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

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

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

    2012-01-01

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

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

    Emilia M Sogin

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

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

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

    2014-01-01

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

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

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

    2013-01-01

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

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

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

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

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

    2014-05-01

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

  3. 1H NMR- based metabolite profiling of tropane alkaloids in Duboisia spec.

    Ullrich, Sophie Friederike

    2016-07-01

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

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

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

    2013-01-01

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

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

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

    1991-12-01

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

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

    Won Woo Kim

    2013-11-01

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

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

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

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

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

    2015-07-21

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

  9. 1H NMR method for simultaneous identification and determination of caffeine and theophylline in human serum and pharmaceutical preparations

    A 1H NMR method for simultaneous identification and determination of caffeine and theophylline in pharmaceutical preparations and human serum has been developed. 1H NMR spectrum of caffeine exhibits three sharp singlets at 2.75, 2.93 and 3.4 ppm, while that of theophyline shows two singlet peaks at 2.77 and 2.97 ppm. For the purpose of quantitative analyses of the mixtures of these two alkaloids 1H NMR spectra of caffeine and theophylline was compared to that of maleic acid as an internal standard at the constant temperature. The suitable peaks were selected and standard deviation and reproducibility of the results were studied applying the full factorial design method. The obtained detection limits are 1.6 μgL-1 and 1.43 μg L1 for caffeine and theophylline, respectively. The average recoveries of the studied applying compounds in various samples, pharmaceutical preparations and human serum ranged from 90.2 to 107.5% (author)

  10. 1H NMR Analysis of Cerebrospinal Fluid from Alzheimer’s Disease Patients: An Example of a Possible Misinterpretation Due to Non-Adjustment of pH

    Thomas Cruz

    2014-02-01

    Full Text Available 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.

  11. 1H NMR Analysis of Cerebrospinal Fluid from Alzheimer's Disease Patients: An Example of a Possible Misinterpretation Due to Non-Adjustment of pH.

    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

  12. Characteristic properties of high- and low-spin-state five-coordinate σ-bonded aryl-, alkyl-, and perfluoroaryliron(III) porphyrins: 1H NMR, ESR, Moessbauer, and magnetic studies

    The magnetic behavior of σ-alkyliron(III) (or σ-aryliron(III)) porphyrins is studied in solution and in solution and in solid state by various spectroscopic methods: 1H NMR, ESR, and 57Fe Moessbauer spectroscopies. Variable-temperature magnetic susceptibility measurements were also performed on these complexes. The iron(III) atom of these compounds is present in different spin states. These are high (S = 5/2) or low spin (S = 1/2) at room temperature. Several factors can affect the spin state, the major parameter being the nature of the axial ligand. The perfluoroaryl axial groups (C6F4H, C6F5) lead to complexes in a pure high-spin state whatever the temperature. In contrast, the (P)Fe(R(Ar)) complexes where R = CH3, Ar = C6H5 and p-MeC6H4, and P = OEP, TPP, T(m-Me)PP, T(p-Me)PP, T(p-Et2N)PP, and (β-CN)4TPP behave differently and are in a low-spin state at room temperature. However, for the latter compounds in frozen solution or in the solid state, some high-spin sites are observed by ESR spectroscopy. The amount is critically dependent on the nature of the axial and porphyrin ligands. Moreover, the solvent matrix appears very important. In the solid state and on the basis of ESR data, the spin mixture could be slightly modified by grinding of the crystalline sample, leading to high-spin entity increase. The effect of these parameters is examined with respect to the nature of the metal-porphyrin and metal-ligand bond. Correlations between stereochemistry, spin state, and the nature of ligands are discussed. 64 refs., 9 figs., 8 tabs

  13. Synthesis, spectral (FT-IR, UV-visible, NMR) features, biological activity prediction and theoretical studies of 4-Amino-3-(4-hydroxybenzyl)-1H-1,2,4-triazole-5(4H)-thione and its tautomer

    Srivastava, Ambrish Kumar; Kumar, Abhishek; Misra, Neeraj; Manjula, P. S.; Sarojini, B. K.; Narayana, B.

    2016-03-01

    Triazole compounds constitute an important class of organic chemistry due to their various biological and corrosion inhibition activities. The synthesis scheme of a new triazole compound namely, 4-Amino-3-(4-hydroxybenzyl)-1H-1,2,4-triazole-5(4H)-thione (4AHT) has been theoretically analyzed. Our density functional theory (DFT) based calculations show that the synthesis of 4AHT is energetically feasible at the room temperature as the reaction is exothermic, spontaneous as well as favored in forward direction. The calculated bond-lengths are found to be in good agreement with corresponding crystallographic values. We have considered two possible tautomers of 4AHT viz. thione and thiol forms. The FT-IR (KBr disc), UV-visible (ethanol) and 1H-NMR (DMSO) spectra of 4AHT have been recorded. The vibrational modes have been assigned on the basis of their potential energy distributions and scaled wavenumbers agree well with the FT-IR wavenumbers. Time dependent DFT calculations are performed to analyze the electronic transitions for various excited states which reproduce the experimental peak observed in UV-visible spectrum. Using gauge independent atomic orbital method 1H-NMR chemical shifts have been calculated and correlated with the experimental chemical shifts with the linear correlation coefficient of 0.9453. Our spectral analyses reveal the dominance of thione over thiol form of 4AHT. The chemical reactivity of 4AHT has been discussed by molecular electrostatic potential surface as well as various electronic parameters. The biological activities of 4AHT have also been explored theoretically and it has been found that the title molecule can act as a potential inhibitor of cyclin-dependent kinase 5 enzyme. These findings may guide the synthesis and design of new triazole compounds with interesting biological activity.

  14. 1H NMR Metabolic Profiling of Biofluids from Rats with Gastric Mucosal Lesion and Electroacupuncture Treatment

    Jingjing Xu

    2015-01-01

    Full Text Available 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.

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

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

    2011-05-01

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

  16. Composition and Quantitation of Microalgal Lipids by ERETIC 1H NMR Method

    Angelo Fontana

    2013-09-01

    Full Text Available Accurate characterization of biomass constituents is a crucial aspect of research in the biotechnological application of natural products. Here we report an efficient, fast and reproducible method for the identification and quantitation of fatty acids and complex lipids (triacylglycerols, glycolipids, phospholipids in microalgae under investigation for the development of functional health products (probiotics, food ingredients, drugs, etc. or third generation biofuels. The procedure consists of extraction of the biological matrix by modified Folch method and direct analysis of the resulting material by proton nuclear magnetic resonance (1H NMR. The protocol uses a reference electronic signal as external standard (ERETIC method and allows assessment of total lipid content, saturation degree and class distribution in both high throughput screening of algal collection and metabolic analysis during genetic or culturing studies. As proof of concept, the methodology was applied to the analysis of three microalgal species (Thalassiosira weissflogii, Cyclotella cryptica and Nannochloropsis salina which drastically differ for the qualitative and quantitative composition of their fatty acid-based lipids.

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

    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

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

    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 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

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

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

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

    David Castejón

    2016-02-01

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

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

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

    2016-01-01

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

  2. NMR studies of metabolism

    In this paper, the authors present applications of NMR to the study of different aspects of metabolism. The authors begin with a brief outline of localization methods that are commonly used to obtain in vivo NMR spectra. The authors then describe in more detail metabolic information recently obtained by NMR of perfused organs, intact animals, and humans. Previous reviews have already covered the applications of NMR to the study of metabolism in microorganisms, isolated or cultivated cells, and tumors. NMR spectroscopy of the brain, and human in vivo NMR spectroscopy have also been reviewed

  3. 1 H NMR-Based Metabonomic Study on Urine from Haematitum-Treated Rats%基于1HNMR给药赭石后大鼠尿液的代谢组学分析

    魏莹; 万传玲; 薛蓉; 李晓晶; 章文军; 裴奉奎

    2016-01-01

    基于1H NMR 的代谢组学方法结合多变量数据分析方法(主成分分析和偏最小二乘判别分析)对灌胃给药赭石(2,5和10 g/ kg 体重剂量)的成年 Wistar 大鼠尿液进行分析,并对大鼠给药前1天、给药后1~5天尿液1 H NMR 数据进行单变量比较分析,筛选出赭石的潜在特征代谢物,对赭石引起的代谢变化进行研究,为赭石的科学用药提供依据。结果表明,大鼠体内柠檬酸、牛磺酸、肌酸酐、α-酮戊二酸、琥珀酸、二甲基甘氨酸等代谢物浓度发生明显变化,随给药时间的变化出现恢复趋势,且恢复趋势与给药剂量相关,可作为赭石的潜在特征代谢物。给药2,5和10 g/ kg 体重剂量赭石降低了大鼠机体三羧酸循环能力,影响了能量、肌酸及二甲基甘氨酸的代谢,且10 g/ kg 体重剂量赭石对大鼠肝功能造成一定影响。%Wistar rats were intragastrically administered with different doses (2, 5 and 10 g / kg body weight) of haematitum. 1H NMR-based metabonomic analysis coupled with multivariate statistical analysis (principal component analysis and partial least squares-discriminant analysis) was used to analyze the metabolic profiles of the urine samples collected from the treated rats. Univariate analysis on the 1H NMR spectra of urine (1 d before administration, 1-5 d post administration) was used to screen out the potential features of haematitum. Significant treatment related changes were observed for the levels of citrate, tuarine, creatinine,α-ketoglutarate, succinate and dimethylglycine, which could be used as potential features of haematitum. A trend of recovery in connection with dose levels was observed overtime. Such biochemical changes indicated that haematitum treatment at the dose of 2, 5 and 10 g / kg body weight affected the Krebs cycle and glucose metabolism, energy metabolism, choline metabolism and dimethylglycine metabolism in rats. These changes may attribute to the disturbances of

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

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

    2006-07-01

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

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

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

    2005-01-01

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

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

    2001-01-01

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

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

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

  8. Soil organic matter dynamics as characterized with 1H and 13C solid-state NMR techniques

    Jäger, Alex; Schwarz, Jette; Bertmer, Marko; Schaumann, Gabriele E.

    2010-05-01

    Soil organic matter (SOM) is a complex and heterogeneous matter. Characterization by solid-state NMR methods on 1H and 13C nuclei is therefore demanding. Our goal is to obtain information on the dynamic behaviour of soil samples and to study the influence of external parameters on both structure and dynamics. We regard water molecules to be the pivotal agent of soil dynamics by generating a network between organic matter via intermolecular hydrogen bonding, which leads to cross linking of organic matter and increases its rigidity. Although 1H solid-state NMR on non-rotating samples are not so commonly used for soil characterization, they enable the differentiation of proton mobilities via their linewidths which are resulting from differences in the dipole-dipole coupling strengths. Therefore, even weak molecular interactions such as hydrogen bonding can be differentiated and changes due to heat treatments and the short and long term behaviour followed. Though in principle a simple technique, static 1H measurements are complicated by several means, one of them is the high abundance in almost all matter including probe head material that has to be excluded for analysis. Finally, we selected 1H DEPTH [1] and Hahn-echo sequences to distinguish different mobilities in soil, mainly free moving water and water fixed in the soil matrix. After decomposition using Gaussian and Lorentzian lineshapes, the relative amounts of mobile and rigid water molecules can be obtained. By heating the samples above 100°C in sealed glass tubes, the proposed water network is destroyed and able to rebuild after cooling. This long term behaviour is studied on the course of months. Furthermore, the instant changes before and after heating are shown for a series of soil samples to characterize soils based on this water network model. To combine the information obtained on the 1H mobility with focus on water dynamics, 13C 2D WISE (wideline separation) measurements were done. This method yields 1

  9. 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

    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.

  10. 1H NMR- based metabolomics approaches as non- invasive tools for diagnosis of endometriosis

    Negar Ghazi

    2016-01-01

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

  11. 1H NMR- based metabolomics approaches as non- invasive tools for diagnosis of endometriosis

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

    2016-01-01

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

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

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

    2015-09-01

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

  13. 1H NMR metabolomics of earthworm responses to polychlorinated biphenyl (PCB) exposure in soil.

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

    2011-06-01

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

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

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

    2015-05-15

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

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

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

    2010-01-01

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

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

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

    2008-01-01

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

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

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

    2003-01-01

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

  18. 基于~1H NMR代谢组学方法的糖尿病溃疡组织代谢特征和病理机制分析%Studies on Metabolic Characteristics and Pathological Mechanisms of Diabetic Ulcers by ~1H NMR-based Metabonomics

    谢丽云; 宋才勇; 娄依依; 徐志; 张美玲; 董柏君; 高红昌; 李校堃

    2011-01-01

    Diabetic ulcer is the most important factor leading to clinical amputation.In the present study, 1H NMR-based metabonomics combined with pathological and biochemical analysis were used to study the metabolic characteristics and pathological mechanisms of diabetic ulcers.The results showed that the fibroblast and blood capillaries proliferation in skin ulcers of diabetic rats were significantly weaker than those in the control rats.From the scores plots of metabonomic studies,we found distinct,easily detectable differences between(a) diabetic ulcer rats and control rats,and(b) diabetic ulcer rats with different healing time.Compared to control skin ulcers,diabetic skin ulcers had lower levels of leucine,isoleucine,alanine, citrate,choline and betaine,together with higher levels of lactate,acetate,pyruvate,creatine,taurine and glycine.Altered metabolite concentrations are most likely the result of the cells switching to glycolysis and creatine metabolism to maintain energy homeostasis following the loss of ATP caused by impaired TCA cycle in diabetic ulcers and to repair the skin trauma.The present study may be able to assist deeply understanding of diabetic ulcers and selection of treatment protocols.%糖尿病溃疡是临床上导致患者截肢的最主要原因,应用基于1H NMR的代谢组学方法研究了链脲佐菌素(STZ)诱导的SD糖尿病大鼠溃疡组织的代谢轮廓,同时结合组织病理和生化分析,阐述了糖尿病溃疡组织的代谢特征和病理机制.结果表明,糖尿病大鼠在溃疡组织愈合过程中的成纤维细胞增殖和毛细血管增生都明显弱于对照组;代谢组学分析的散点图表明糖尿病溃疡组和对照组在代谢模式上明显分开,不同愈合时间的糖尿病溃疡组在代谢模式上明显分开;载荷图表明糖尿病溃疡组相对于对照组,亮氨酸、异亮氨酸、丙氨酸、柠檬酸、胆碱和甜菜碱等代谢成分含量降低;而乳酸、醋酸、丙酮酸、

  19. Sequence-specific Assignment of 1H-NMR Resonance and Determination of the Secondary Structure of Jingzhaotoxin-Ⅰ

    Xiong-Zhi ZENG; Qi ZHU; Song-Ping LIANG

    2005-01-01

    Jingzhaotoxin-Ⅰ (JZTX-Ⅰ) purified from the venom of the spider Chilobrachys jingzhao is a novel neurotoxin preferentially inhibiting cardiac sodium channel inactivation by binding to receptor site 3.The structure of this toxin in aqueous solution was investigated using 2-D 1H-NMR techniques. The complete sequence-specific assignments of proton resonance in the 1H-NMR spectra of JZTX-Ⅰ were obtained by analyzing a series of 2-D spectra, including DQF-COSY, TOCSY and NOESY spectra, in H2O and D2O. All the backbone protons except for Gln4 and more than 95% of the side-chain protons were identified by dαN,dαδ, dβN and dNN connectivities in the NOESY spectrum. These studies provide a basis for the further determination of the solution conformation of JZTX-Ⅰ. Furthermore, the secondary structure of JZTX-Ⅰ was identified from NMR data. It consists mainly of a short triple-stranded antiparallel β-sheet with Trp7-Cys9, Phe20-Lys23 and Leu28-Trp31. The characteristics of the secondary structure of JZTX-Ⅰ are similar to those of huwentoxin-Ⅰ (HWTX-Ⅰ) and hainantoxin-Ⅳ (HNTX-Ⅳ), whose structures in solution have previously been reported.

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

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

    2010-09-01

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

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

    Anick David J

    2004-11-01

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

  2. Human urine as test material in 1H NMR-based metabonomics: recommendations for sample preparation and storage.

    Lauridsen, Michael; Hansen, Steen H; Jaroszewski, Jerzy W; Cornett, Claus

    2007-02-01

    Metabonomic approaches are believed to have the capability of revolutionizing diagnosis of diseases and assessment of patient conditions after medical interventions. In order to ensure comparability of metabonomic 1H NMR data from different studies, we suggest validated sample preparation guidelines for human urine based on a stability study that evaluates effects of storage time and temperature, freeze-drying, and the presence of preservatives. The results indicated that human urine samples should be stored at or below -25 degrees C, as no changes in the 1H NMR fingerprints have been observed during storage at this temperature for 26 weeks. Formation of acetate, presumably due to microbial contamination, was occasionally observed in samples stored at 4 degrees C without addition of a preservative. Addition of a preserving agent is not mandatory provided that the samples are stored at -25 degrees C. Thus, no differences were observed between 1H NMR spectra of nonpreserved urines and urines with added sodium azide and stored at -25 degrees C, whereas the presence of sodium fluoride caused a shift of especially citrate resonances. Freeze-drying of urine and reconstitution in D2O at pH 7.4 resulted in the disappearance of the creatinine CH2 signal at delta 4.06 due to deuteration. A study evaluating the effects of phosphate buffer concentration on signal variability and assessment of the probability of citrate or creatinine resonances crossing bucket border (a boundary between adjacent integrated regions) led to the conclusion that a minimum buffer concentration of 0.3 M is adequate for normal urines used in this study. However, final buffer concentration of 1 M will be required for very concentrated urines. PMID:17263352

  3. 1H and 13C NMR investigation of 20-hydroxyecdysone dioxolane derivatives, a novel group of MDR modulator agents.

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

    2013-12-01

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

  4. 15N and 1H NMR evidence for multiple conformations of the complex of dihydrofolate reductase with its substrate, folate

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

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

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

    2005-06-29

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

  6. Pore size distribution calculation from {sup 1}H NMR signal and N{sub 2} adsorption-desorption techniques

    Hassan, Jamal, E-mail: jamal.hassan@kustar.ac.ae [Department of Applied Mathematics and Sciences, KU (United Arab Emirates); Department of Physics and Astronomy, University of Waterloo, Waterloo, Ontario, N2L 3G1 (Canada)

    2012-09-15

    The pore size distribution (PSD) of nano-material MCM-41 is determined using two different approaches: N{sub 2} adsorption-desorption and {sup 1}H 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 A for the modified Kelvin and NMR methods respectively. A comparison between these methods and the classical Kelvin equation is also presented.

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

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

    2016-06-01

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

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

    黄奇骏; 姚婕; 黎玉君; 翁合妹; 龚嘉欣; 丘翠环; 杨永霞

    2013-01-01

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

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

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

    2012-01-01

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

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

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

    2014-01-01

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

  11. Study of the effect hydrogen binding in the solvation of alkaline earth cations with MeOH in nitromethane using 1 H NMR technique and determination of ionic solvation number

    Alizadeh, N

    2001-01-01

    A proton NMR method for the study of the effect hydrogen binding and determination of solvation numbers of alkaline earth cations with methanol (MeOH) in in tromethane (NM) as diluent is described. The method is based on monitoring the resonance frequency of MeOH protons as a function of MeOH to metal ion mole ratio at constant metal ion concentration. the average solvation number of cation, n, at any MeOH/ metal ion mole ration was calculated from the NMR chemical shift-mole ration data and was plotted against the mole ration values. The solvation numbers of alkaline earth cations were obtained from the limiting values of the corresponding n, vs. mole ratio plots.

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

    Dominik Strzelecki

    2015-10-01

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

  13. Formation of 1:1 and 2:1 host-guest inclusion complexes of α-cyclodextrin with cycloalkanols: A 1H and 13C NMR spectroscopic study

    Akita, Tomoki; Yoshikiyo, Keisuke; Yamamoto, Tatsuyuki

    2014-09-01

    Binding constants (Ka's) for the formation of inclusion complexes of α-cyclodextrin (α-CD) with cycloalkanols (c-CnOH; n = 4-8) were determined by means of 1H and 13C NMR titration, under two different conditions: (i) only 1:1 host-guest inclusion complexes are formed when the guest is in excess; (ii) the formation of 2:1 inclusion complexes occurs only after that of 1:1 inclusion complexes, when the host is in excess. The results of this work showed that α-CD can include c-C4OH or c-C5OH only when the molar ratio is 1:1; larger ring-sized cycloalkanols such as c-C6OH, c-C7OH or c-C8OH can be included only when the molar ratio is 2:1. These findings, together with those obtained for the four derivatives of α-CD, per-6-O-methyl-α-CD, per-2-O-methyl-α-CD, per-3-O-methyl-α-CD, and per-2,6-di-O-methyl-α-CD, suggested that α-CD forms 2:1 inclusion complexes with c-C6OH, c-C7OH or c-C8OH in a tail-to-tail manner, in which the secondary hydroxy sides of the two CD molecules face each other. Two-dimensional ROESY measurements confirmed our results.

  14. Molecular structures and conformations of 1-benzenesulphonyl-2-oxo-5-alkoxypyrrolidines with anti-amnesic activity. X-ray, 1H-NMR and quantum mechanical (PM3) studies

    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.

  15. Changes in Lignin and Polysaccharide Components in 13 Cultivars of Rice Straw following Dilute Acid Pretreatment as Studied by Solution-State 2D 1H-13C NMR.

    Hiroshi Teramura

    Full Text Available A renewable raw material, rice straw is pretreated for biorefinery usage. Solution-state two-dimensional (2D 1H-13 C hetero-nuclear single quantum coherence (HSQC nuclear magnetic resonance (NMR spectroscopy, was used to analyze 13 cultivars of rice straw before and after dilute acid pretreatment, to characterize general changes in the lignin and polysaccharide components. Intensities of most (15 of 16 peaks related to lignin aromatic regions, such as p-coumarate, guaiacyl, syringyl, p-hydroxyphenyl, and cinnamyl alcohol, and methoxyl, increased or remained unchanged after pretreatment. In contrast, intensities of most (11 of 13 peaks related to lignin aliphatic linkages or ferulate decreased. Decreased heterogeneity in the intensities of three peaks related to cellulose components in acid-insoluble residues resulted in similar glucose yield (0.45-0.59 g/g-dry biomass. Starch-derived components showed positive correlations (r = 0.71 to 0.96 with glucose, 5-hydroxymethylfurfural (5-HMF, and formate concentrations in the liquid hydrolysates, and negative correlations (r = -0.95 to -0.97 with xylose concentration and acid-insoluble residue yield. These results showed the fate of lignin and polysaccharide components by pretreatment, suggesting that lignin aromatic regions and cellulose components were retained in the acid insoluble residues and starch-derived components were transformed into glucose, 5-HMF, and formate in the liquid hydrolysate.

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

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

    2014-06-23

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

  17. 1H NMR Relaxation Investigation of Inhibitors Interacting with Torpedo californica Acetylcholinesterase

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

    2000-05-01

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

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

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

    2017-02-01

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

  19. High-field {sup 1}H NMR microscopy for fundamental biophysical research; Hochfeld {sup 1}H-NMR-Mikroskopie zur biophysikalischen Grundlagenforschung

    Haddad, D.

    2003-08-08

    This work has a biophysical background and uses different examples to demonstrate the practical applicability of NMR-Microscopy in the medical and biological sector. Therefore, the different projects are feasibility studies which are used to compare the possibilities and advantages of NMR-Microscopy with other, established examination techniques. In detail, using MR-Microscopy, different living and fixed biological samples have been visualized non-invasively with high spatial resolution. The specific purpose of the studies ranged from the visualization of the invasion of tumor-spheroids into cell aggregates using T2 parameter maps (time constant of the spin-spin relaxation) to the three-dimensional display of the honey bee brain in the intact head capsule and the non-invasive visualization of the anatomy of prenatal dolphins. For all these projects, the non-invasive character of MR-experiments was of utmost importance. The tumor invasion was not to be disturbed by the measurements, the bee brain should be visualized as close to its true natural shape as possible and the examined dolphins represent rare museum specimens which should not be destroyed. The different samples were all imaged with the best possible spatial resolution which was either limited by the necessary signal-to-noise ratio (SNR) or the available scan time. In order to resolve single details and fine structures in the images, it was necessary to optimize the SNR as well as the contrast-to-noise ratio. To guarantee the necessary SNR, the measurements were performed on high field MR-spectrometers with resonance frequencies of 500 and 750 MHz.

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

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

    2014-01-01

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

  1. Validation of quantitative 1H NMR method for the analysis of pharmaceutical formulations

    The need for effective and reliable quality control in products from pharmaceutical industries renders the analyses of their active ingredients and constituents of great importance. This study presents the theoretical basis of ¹H NMR for quantitative analyses and an example of the method validation according to Resolution RE N. 899 by the Brazilian National Health Surveillance Agency (ANVISA), in which the compound paracetamol was the active ingredient. All evaluated parameters (selectivity, linearity, accuracy, repeatability and robustness) showed satisfactory results. It was concluded that a single NMR measurement provides structural and quantitative information of active components and excipients in the sample. (author)

  2. 1H NMR-based metabolite profiling of diet-induced obesity in a mouse mode

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

    2012-07-01

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

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

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

    2006-06-01

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

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

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

    2015-09-25

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

  5. 1H NMR-based spectroscopy detects metabolic alterations in serum of patients with early-stage ulcerative colitis

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

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

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

    2013-04-19

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

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

    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

  8. 1H NMR metabolic fingerprinting to probe temporal postharvest changes on qualitative attributes and phytochemical profile of sweet cherry fruit

    Vlasios eGoulas

    2015-11-01

    Full Text Available 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-coumarolquinic 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 to 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.

  9. 1H NMR Metabolic Fingerprinting to Probe Temporal Postharvest Changes on Qualitative Attributes and Phytochemical Profile of Sweet Cherry Fruit

    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

  10. Investigation of network heterogeneities in filled, trimodal, highly functional PDMS networks by 1H Multiple Quantum NMR

    Gjersing, E; Chinn, S; Maxwell, R S; Herberg, J; Eastwood, E; Bowen, D; Stephens, T

    2006-09-06

    The segmental order and dynamics of polymer network chains in a filled, tri-modal silicone network have been studied by static 1H Multiple Quantum (MQ) NMR methods to gain insight into the structure property relationships. The materials were synthesized with two different types of crosslinks, with functionalities of 4 and near 60. The network chains were composed of distributions of high, low, and medium molecular weight chains. Crosslinking was accomplished by standard acid catalyzed reactions. MQ NMR methods have detected domains with residual dipolar couplings (<{Omega}{sub d}>) of near 4 kRad/s and 1 kRad/s assigned to (a) the shorter polymer chains and chains near the multifunctional ({phi}=60) crosslinking sites and to (b) the longer polymer chains far from these sites. Three structural variables were systematically varied and the mechanical properties and distributions of residual dipolar couplings measured in order to gain insight in to the network structural motifs that contribute significantly to the composite properties. The partitioning of and the average values of the residual dipolar couplings for the two domains were observed to be dependent on formulation variable and provided increased insight into the mechanical properties of these materials which are unavailable from swelling and spin-echo methods. The results of this study suggest that the domains with high crosslink density contribute significantly to the high strain modulus, while the low crosslink density domains do not. This is in agreement with theories and experimental studies on silicone bimodal networks over the last 20 years. In-situ MQ-NMR of swollen sample suggests that the networks deform non-affinely, in agreement with theory. The NMR experiments shown here provide increased ability to characterize multimodal networks of typical engineering silicone materials and to gain significant insight into structure-property relationships.

  11. Investigation of network heterogeneities in filled, trimodal, highly functional PDMS networks by 1H Multiple Quantum NMR

    Maxwell, R; Gjersing, E; Chinn, S; Giuliani, J; Herberg, J; Eastwood, E; Bowen, D; Stephens, T

    2007-03-20

    The segmental order and dynamics of polymer network chains in a filled, tri-modal silicone foam network have been studied by static 1H Multiple Quantum (MQ) NMR methods to gain insight into the structure property relationships. The foam materials were synthesized with two different types of crosslinks, with functionalities, {phi}, of 4 and near 60. The network chains were composed of distributions of high, low, and medium molecular weight chains. Crosslinking was accomplished by standard acid catalyzed reactions. MQ NMR methods have detected domains with residual dipolar couplings (<{Omega}{sub d}>) of near 4 kRad/s and 1 kRad/s assigned to (a) the shorter polymer chains and chains near the multifunctional (f=60) crosslinking sites and to (b) the longer polymer chains far from these sites. Three structural variables were systematically varied and the mechanical properties via compression and distributions of residual dipolar couplings measured in order to gain insight in to the network structural motifs that contribute significantly to the composite properties. The partitioning of and the average values of the residual dipolar couplings for the two domains were observed to be dependent on formulation variable and provided increased insight into the network structure of these materials which are unavailable from swelling and spin-echo methods. The results of this study suggest that the domains with high crosslink density contribute significantly to the high strain modulus, while the low crosslink density domains do not. This is in agreement with theories and experimental studies on silicone bimodal networks over the last 20 years. In-situ MQ-NMR of swollen sample suggests that the networks deform heterogeneously and non-affinely. The heterogeneity of the deformation process was observed to depend on the amount of the high functionality crosslinking site PMHS. The NMR experiments shown here provide increased ability to characterize multimodal networks of typical

  12. Isolation and quantification of pinitol in Argyrolobium roseum plant, by 1H-NMR

    Neha Sharma

    2016-01-01

    Full Text Available Chemical investigations on ethanolic extract of Argyrolobium roseum led to the isolation of Pinitol as the major constituent of the plant. Pinitol is chemically known as 3-O-methyl-D-Chiro-inositol and has been found to possess anti-diabetic activity. It helps in the regeneration of beta cells, present in the areas of the pancreas called as islets – of Langerhans. These cells make and release insulin, a hormone which controls the level of glucose in the blood. Pinitol was isolated from the ethanolic extract of the plant and a sensitive & reliable method, based on Proton Nuclear Magnetic Resonance (PNMR, was developed and used as an analytical tool for quantification and identification of this relatively UV insensitive compound in the alcoholic extract of the plant. The method involves the use of pyrazinamide (an anti-tuberculosis drug, as a reference. Validation of the method was carried out by preparing a known concentration of an artificial mixture of pinitol and pyrazinamide. The recovery of pinitol in the mixture was in the range of 98.5–101.3%. Pinitol in pure form was isolated from the ethanolic extract of A. roseum by repeated column chromatography over silica gel followed by crystallization in methanol. Pinitol isolated from the plant was identified on the basis of 1H-NMR, 13C-NMR, DEPT (45°, 90° and 135° experiments and mass spectral data. The method was successfully applied for the quantitation of pinitol in various extracts of the said plant.

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

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

  14. 1H MAS NMR characterization of hydrogen over silica-supported rhodium catalyst

    2001-01-01

    Hydrogen species in both SiO2 and Rh/SiO2 catalysts pretreated indifferent atmospheres (H2, O2, helium or air) at different temperatures (773 or 973 K) were investigated by means of 1H MAS NMR. In SiO2 and O2-pretreated catalysts, a series of downfield signals at ~7.0, 3.8-4.0, 2.0 and 1.5-1.0 were detected. The first two signals can be attributed to strongly adsorbed and physisorbed water and the others to terminal silanol (SiOH) and SiOH under the screening of oxygen vacancies in SiO2 lattice, respectively. Besides the above signals, both upfield signal at ~-110 and downfield signals at 3.0 and 0.0 were also detected in H2-pretreated catalyst, respectively. The upfield signal at ~-110 originated from the dissociative adsorption of H2 over rhodium and was found to consist of both the contributions of reversible and irreversible hydrogen. There also probably existed another dissociatively adsorbed hydrogen over rhodium, which was known to be b hydrogen and in a unique form of "delocalized hydrogen". It was presumed that the b hydrogen had an upfield shift of ca. -20- -50, though its 1H NMR signals, which, having been masked by the spinning sidebands of Si-OH, failed to be directly detected out. The downfield signal at 3.0 was assigned to spillover hydrogen weakly bound by the bridge oxygen of SiO2. Another downfield signal at 0.0 was assigned to hydrogen held in the oxygen vacancies of SiO2 (Si-H species), suffering from the screening of trapped electrons. Both the spillover hydrogen and the Si-H resulted from the migration of the reversible hydrogen and the b hydrogen from rhodium to SiO2 in the close vicinity. It was proved that the above migration of hydrogen was preferred to occur at higher temperature than at lower temperature.

  15. {sup 1}H NMR-based metabolomics of time-dependent responses of Eisenia fetida to sub-lethal phenanthrene exposure

    Lankadurai, Brian P.; Wolfe, David M.; Simpson, Andre J. [Department of Chemistry, University of Toronto, 1265 Military Trail, Toronto, Ontario M1C 1A4 Canada (Canada); Simpson, Myrna J., E-mail: myrna.simpson@utoronto.ca [Department of Chemistry, University of Toronto, 1265 Military Trail, Toronto, Ontario M1C 1A4 Canada (Canada)

    2011-10-15

    {sup 1}H NMR-based metabolomics was used to examine the response of the earthworm Eisenia fetida after exposure to sub-lethal concentrations of phenanthrene over time. Earthworms were exposed to 0.025 mg/cm{sup 2} of phenanthrene (1/64th of the LC{sub 50}) via contact tests over four days. Earthworm tissues were extracted using a mixture of chloroform, methanol and water, resulting in polar and non-polar fractions that were analyzed by {sup 1}H NMR after one, two, three and four days. NMR-based metabolomic analyses revealed heightened E. fetida responses with longer phenanthrene exposure times. Amino acids alanine and glutamate, the sugar maltose, the lipids cholesterol and phosphatidylcholine emerged as potential indicators of phenanthrene exposure. The conversion of succinate to fumarate in the Krebs cycle was also interrupted by phenanthrene. Therefore, this study shows that NMR-based metabolomics is a powerful tool for elucidating time-dependent relationships in addition to the mode of toxicity of phenanthrene in earthworm exposure studies. - Highlights: > NMR-based earthworm metabolomic analysis of the mode of action of phenanthrene is presented. > The earthworm species E. fetida were exposed to sub-lethal phenanthrene concentrations. > Both polar and non-polar metabolites of E. fetida tissue extracts were analyzed by {sup 1}H NMR. > Longer phenanthrene exposure times resulted in heightened earthworm responses. > An interruption of the Krebs cycle was also observed due to phenanthrene exposure. - {sup 1}H NMR metabolomics is used to determine the relationship between phenanthrene exposure and the metabolic response of the earthworm E. fetida over time and also to elucidate the phenanthrene mode of toxicity.

  16. SAFT缔合模型关联含水体系的1H NMR%Correlation of 1H NMR Chemical Shift for Aqueous Solutions by Statistical Associating Fluid Theory Association Model

    许波; 李浩然; 王从敏; 许映杰; 韩世钧

    2005-01-01

    1H NMR chemical shifts of binary aqueous mixtures of acylamide, alcohol, dimethyl sulphoxide (DMSO), and acetone are correlated by statistical associating fluid theory (SAFT) association model. The comparison between SAFT association model and Wilson equation shows that the former is better for dealing with aqueous solutions. Finally, the specialties of both models are discussed.

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

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

    2016-08-01

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

  18. Three-dimensional solution structure of ω-conotoxin SO3 determined by 1H NMR

    2003-01-01

    Cone snails (Conus) elaborate a series of conotoxin (CTX) peptides in their venoms to paralyze their prey. Among these toxins, ω-CTX's specifically target to presynaptic voltage-gated calcium channel subsets, causing inhibition of neurotransmitter release. Ω-CTX SO3 was isolated from the venom of Conus striatus, which is the only available fish-hunting snail near the coast of the South China Sea. The three-dimensional solution structure of ω-CTX SO3, a peptide which is the only ω-conotoxin reported to show high homology with another ω-CTX (MVIIA from C. Magus), has been determined by 1H NMR techniques. The molecular structure of ω-CTX SO3 is stabilized by three disulfide bridges and a short triple-stranded antiparallel ω-sheet with four turns. A comprehensive comparison suggested that the backbone conformation of ω-CTX's was quite conserved, while the length of ω-sheet and the type of some turns might have minor differences.

  19. 1H NMR Spectroscopy and MVA Analysis of Diplodus sargus Eating the Exotic Pest Caulerpa cylindracea

    Sandra A. De Pascali

    2015-06-01

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

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

    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

  1. Toward the solution structure of human insulin: Sequential 2D 1H NMR assignment of a des-pentapeptide analogue and comparison with crystal structure

    2D 1H NMR studies are presented of des-pentapeptide-insulin, an analogue of human insulin lacking the C-terminal five residues of the B chain. Removal of these residues, which are not required for function, is shown to reduce conformational broadening previously described in the spectrum of intact insulin. This difference presumably reflects more rapid internal motions in the fragment, which lead to more complete averaging of chemical shifts on the NMR time scale. Sequential 1H NMR assignment and preliminary structural analysis demonstrate retention in solution of the three α-helices observed in the crystal state and the relative orientation of the receptor-binding surfaces. These studies provide a foundation for determining the solution structure of insulin

  2. Toward the solution structure of human insulin: Sequential 2D sup 1 H NMR assignment of a des-pentapeptide analogue and comparison with crystal structure

    Hua, Q.; Weiss, M.A. (Harvard Medical School, Boston, MA (USA) Massachusetts Institute of Technology, Cambridge (USA))

    1990-11-01

    2D {sup 1}H NMR studies are presented of des-pentapeptide-insulin, an analogue of human insulin lacking the C-terminal five residues of the B chain. Removal of these residues, which are not required for function, is shown to reduce conformational broadening previously described in the spectrum of intact insulin. This difference presumably reflects more rapid internal motions in the fragment, which lead to more complete averaging of chemical shifts on the NMR time scale. Sequential {sup 1}H NMR assignment and preliminary structural analysis demonstrate retention in solution of the three {alpha}-helices observed in the crystal state and the relative orientation of the receptor-binding surfaces. These studies provide a foundation for determining the solution structure of insulin.

  3. Investigation on Acute Biochemical Effects of Ce(NO3)3 on Liver and Kidney Tissues by MAS 1H NMR Spectroscopic-Based Metabonomic Approach

    2006-01-01

    High resolution magic angle spinning (MAS)-1 H nuclear magnetic resonance (NMR) spectroscopic-based metabonomic approach was applied to the investigation on the acute biochemical effects of Ce(NO3)3. Male Wistar rats were liver and kidney tissues were analyzed using principal component analysis to extract toxicity information. The biochemical effects of Ce(NO3)3 were characterized by the increase of triglycerides and lactate and the decrease of glycogen in rat liver tissue, together with an elevation of the triglyceride level and a depletion of glycerophosphocholine and betaine in kidney tissues. The target lesions of Ce(NO3)3 on liver and kidney were found by MAS NMR-based metabonomic method. This study demonstrates that the combination of MAS 1H NMR and pattern recognition analysis can be an effective method for studies of biochemical effects of rare earths.

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

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

    2014-12-01

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

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

    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

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

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

    Weber, Adrian C. J., E-mail: WeberA@BrandonU.CA [Chemistry Department, Brandon University, 270-18th Street, Brandon, Manitoba R7A 6A9 (Canada); Burnell, E. Elliott, E-mail: elliott.burnell@ubc.ca [Chemistry Department, University of British Columbia, 2036 Main Mall, Vancouver, British Columbia V6T 1Z1 (Canada); Meerts, W. Leo, E-mail: leo.meerts@science.ru.nl [Radboud University, Institute for Molecules and Materials, Heyendaalseweg 135, NL-6525 AJ Nijmegen (Netherlands); Atomic, Molecular and Laser Physics, Vrije Universiteit, De Boelelaan 1081, 1081 HV Amsterdam (Netherlands); Lange, Cornelis A. de, E-mail: c.a.de.lange@vu.nl [Atomic, Molecular and Laser Physics, Vrije Universiteit, De Boelelaan 1081, 1081 HV Amsterdam (Netherlands); Dong, Ronald Y., E-mail: rondong@phas.ubc.ca [Department of Physics and Astronomy, University of British Columbia, 6224 Agricultural Road, Vancouver, British Columbia V6T 1Z1 (Canada); Muccioli, Luca, E-mail: Luca.Muccioli@unibo.it; Pizzirusso, Antonio, E-mail: Antonio.Pizzirusso80@gmail.com; Zannoni, Claudio, E-mail: Claudio.Zannoni@unibo.it [Dipartimento di Chimica Industriale “Toso Montanari,” Università di Bologna and INSTM, viale Risorgimento 4, 40136 Bologna (Italy)

    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.

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

    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

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

    Vanessa R. Pegos

    2014-04-01

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

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

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

  11. Correlation of 1H NMR Chemical Shift for Aqueous Solutions by Statistical Associating Fluid Theory Association Model

    许波; 李浩然; 王从敏; 许映杰; 韩世钧

    2005-01-01

    1H NMR chemical shifts of binary aqueous mixtures of acylamide, alcohol, dimethyl sulphoxide (DMSO), and acetone are correlated by statistical associating fluid theory (SAFT) association model. The comparison between SAFT association model and Wilson equation shows that the former is better for dealing with aqueous solutions. Finally, the specialties of both models are discussed.

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

    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…

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

    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

  14. (1)H, (13)C and (15)N NMR assignments of a calcium-binding protein from Entamoeba histolytica.

    Verma, Deepshikha; Bhattacharya, Alok; Chary, Kandala V R

    2016-04-01

    We report almost complete sequence specific (1)H, (13)C and (15)N NMR assignments of a 150-residue long calmodulin-like calcium-binding protein from Entamoeba histolytica (EhCaBP6), as a prelude to its structural and functional characterization. PMID:26377206

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

    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.

  16. Chiral trimethylsilylated C2-symmetrical diamines as phosphorous derivatizing agents for the determination of the enantiomeric excess of chiral alcohols by 1H NMR

    Alexakis Alexandre

    2006-03-01

    Full Text Available Abstract The use of organophosphorus derivatising agents, prepared from C2 symmetric trimethylsilylated diamines, for the 1H NMR and 31P NMR determination of the enantiomeric composition of chiral alcohols is described.

  17. Statistical removal of background signals from high-throughput 1H NMR line-broadening ligand-affinity screens

    NMR ligand-affinity screens are vital to drug discovery, are routinely used to screen fragment-based libraries, and used to verify chemical leads from high-throughput assays and virtual screens. NMR ligand-affinity screens are also a highly informative first step towards identifying functional epitopes of unknown proteins, as well as elucidating the biochemical functions of protein–ligand interaction at their binding interfaces. While simple one-dimensional 1H NMR experiments are capable of indicating binding through a change in ligand line shape, they are plagued by broad, ill-defined background signals from protein 1H resonances. We present an uncomplicated method for subtraction of protein background in high-throughput ligand-based affinity screens, and show that its performance is maximized when phase-scatter correction is applied prior to subtraction

  18. Statistical removal of background signals from high-throughput {sup 1}H NMR line-broadening ligand-affinity screens

    Worley, Bradley; Sisco, Nicholas J.; Powers, Robert, E-mail: rpowers3@unl.edu [University of Nebraska-Lincoln, Department of Chemistry (United States)

    2015-09-15

    NMR ligand-affinity screens are vital to drug discovery, are routinely used to screen fragment-based libraries, and used to verify chemical leads from high-throughput assays and virtual screens. NMR ligand-affinity screens are also a highly informative first step towards identifying functional epitopes of unknown proteins, as well as elucidating the biochemical functions of protein–ligand interaction at their binding interfaces. While simple one-dimensional {sup 1}H NMR experiments are capable of indicating binding through a change in ligand line shape, they are plagued by broad, ill-defined background signals from protein {sup 1}H resonances. We present an uncomplicated method for subtraction of protein background in high-throughput ligand-based affinity screens, and show that its performance is maximized when phase-scatter correction is applied prior to subtraction.

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

    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

  20. 1H and 7Li NMR in li2-xhxmo3 (m = Ti, Zr)

    Baklanova, Ya

    2008-01-01

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

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

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

    2012-06-01

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

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

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

    2016-08-10

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

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

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

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

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

    2014-10-31

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

  5. 1H NMR Spectroscopy and Multivariate Analysis of Monovarietal EVOOs as a Tool for Modulating Coratina-Based Blends

    Laura Del Coco

    2014-04-01

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

  6. Functional studies using NMR

    This volume is based on a series of lectures delivered at a one-day teaching symposium on functional and metabolic aspects of NMR measurements held at the Middlesex Hospital Medical School on 1st September 1985 as a part of the European Nuclear Medicine Society Congress. Currently the major emphasis in medical NMR in vivo is on its potential to image and display abnormalities in conventional radiological images, providing increased contrast between normal and abnormal tissue, improved definition of vasculature, and possibly an increased potential for differential diagnosis. Although these areas are undeniably of major importance, it is probable that NMR will continue to complement conventional measurement methods. The major potential benefits to be derived from in vivo NMR measurements are likely to arise from its use as an instrument for functional and metabolic studies in both clinical research and in the everyday management of patients. It is to this area that this volume is directed

  7. Synthesis, X-ray crystallography, spectroscopic (FT-IR, 1H &13C NMR and UV), computational (DFT/B3LYP) and enzymes inhibitory studies of 7-hydroximinocholest-5-en-3-ol acetate

    Ahmad, Faheem; Parveen, Mehtab; Alam, Mahboob; Azaz, Shaista; Malla, Ali Mohammed; Alam, Mohammad Jane; Lee, Dong-Ung; Ahmad, Shabbir

    2016-07-01

    The present study reports the synthesis of 7-Hydroximinocholest-5-en-3-ol acetate (syn. 3β-acetoxycholest-5-en-7-one oxime; in general, steroidal oxime). The identity of steroidal molecule was confirmed by NMR, FT-IR, MS, CHN microanalysis and X-ray crystallography. DFT calculations on the titled molecule have been performed. The molecular structure and spectra interpreted by Gaussian hybrid computational analysis theory (B3LYP) are found to be in good correlation with the experimental data obtained from the various spectrophotometric techniques. The vibrational bands appearing in the FTIR are assigned with great accuracy using harmonic frequencies along with intensities and animated modes. Molecular properties like HOMO-LUMO analysis, chemical reactivity descriptors, MEP mapping, dipole moment and natural atomic charges have been presented at the same level of theory. Moreover, the Hirshfeld analysis was carried out to ascertain the secondary interactions and associated 2D fingerprint plots. The percentages of various interactions are pictorialized by fingerprint plots of Hirshfeld surface. Steroidal oxime exhibited promising inhibitory activity against acetylcholinesterase (AChE) as compared to the reference drug, tacrine. Molecular docking was performed to introduce steroidal molecules into the X-ray crystal structures of acetylcholinesterase at the active site to find out the probable binding mode. The results of molecular docking admitted that steroidal oxime may exhibit enzyme inhibitor activity.

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

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

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

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

    2007-02-28

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

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

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

    2007-02-28

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

  11. X-ray, 1H/13C 2D and 3D NMR studies of the structures of davallene and adipedatol, two triterpenes isolated from American Adiantum capillus-veneris

    Two triterpenic compounds Davallene 1 and Adipedatol 2 were isolated from the roots of Mexican Adiantum capillus-veneris (Adiantaceae). The structures of both compounds are discussed on the basis of new 2D and 3D NMR spectroscopic and single crystal X-ray diffraction data. (author)

  12. Magic-angle-spinning NMR studies of zeolite SAPO-5

    Freude, D.; Ernst, H.; Hunger, M.; Pfeifer, H.; Jahn, E.

    1988-01-01

    SAPO-5 was synthesized using triethylamine as template. Magic-angle-spinning (MAS) NMR of 1H, 27Al, 29Si and 31P was used to study the silicon incorporation into the framework and the nature of the Brønsted sites. 1H MAS NMR shows two types of bridging hydroxyl groups. 29Si MAS NMR indicates that silicon substitutes mostly for phosphorus and that there is a small amount of crystalline SiO 2 in the zeolite powder.

  13. Studies on irradiation stability of polystyrene by NMR

    ZHAO Xin; SUN Wan-Fu; XIE Cheng-Xi

    2004-01-01

    The irradiation stability of polystyrene (PS) was studied by 13C and 1H NMR spectra, Nuclear Overhauser Relaxation (NOE) and 13C NMR spin-lattice relaxation time (T1). The results indicate that 13C and 1H NMR chemical shifts, NOE and T1 were almost invariant with the increase of irradiation dose. This shows that polystyrene is particularly stable within 2.5 kGy doses and the mechanism of its stability is discussed.

  14. Metabonomic study on early biomarkers of hepatic injury induced by ethanolic extract from Rhizoma Dioscoreae Bulbiferae in rats based on 1H-NMR%基于1H-核磁共振代谢组学研究黄药子乙醇提取物致肝损伤的潜在生物标志物

    盛云华; 乔靖怡; 金若敏; 姚广涛; 周璐; 唐黎明

    2016-01-01

    Rhizoma Dioscoreae Bulbiferae(RDB)was investigated by 1H-NMR-based metabo⁃nomic methods in order to discover early biomarkers of liver toxicity induced by RDB. METHODS Rats were ig adminisetred with RDB at a dose of 5 g·kg-1 for 28 d. Rats were sacrificed 3,7,14 and 28 d af⁃ter RDB administration,as well as after a recovery period,respectively. Blood was taken for routine bio⁃chemical analysis by an automatic biochemical analyzer. Liver/body mass indexes were calculated ,and liver pathological changes were observed with hematoxylin-eosin staining. Urine samples were collected before and 3,7,14 and 28 d after RDB administration,respectively,as well as after withdrawal. Metabo⁃nomic analysis was carried out for serum and urine samples. Principal component analysis and orthogonal partial least squares-discriminant analysis were used for screening and identifiying early biomarkers. RESULTS Compared with the control group,total bilirubin (TB) and total cholesterol (TC) values were increased in 3-28 d in RDB group(P<0.05,P<0.01). Total bile acid(TBA)was elevated in 7-28 d (P<0.05,P<0.01). TB,TC and TBA became normal after discontinuation with RDB. There was no significant difference between RBD-treated group and control group in the activity of glutamic-pyruvic transaminase and glutamic-oxaloacetic transaminase,and the content of glucose also was not different between the two groups. The ratio of liver/body mass was elevated at 3-28 d(P<0.01)but returned to normal after withdraval of RDB. The enlargement and necrosis of hepatocytes were observed 7 d after RDB administration,and lesion degree was aggravated with the extension of RDB delivery time. Meta⁃bonomic analysis showed that the serum lipids (low density lipoprotein/very low density lipoprotein (LDL/VLDL),glutamic acid,choline phosphate and glycerolphosphatecholine were increased in the early stage. Pyruvate and N-acetylglutamate were decreased in urine. These metabolites became normal 7 d after discontinuation

  15. Investigation of imbibed water in wheat grains (Triticum aestivum L.) by pulsed 1H-NMR

    The population of water fractions (liquid phase and macromolecular bound phase) in wheat grains was investigated by separation of the NMR-signal components characterized by different spin-spin relaxation times. The state of the bound water (hydration water) was studied by analyzing the spin-spin and spin-lattice relaxation times in dependence on water content. Results are discussed in terms of a continuous distribution of the bound water correlation times. In the range of investigated water content (f approximately 6 - 18%) bound water is dominating. The signal intensity of the liquid component remains constant until f approximately 13%. At higher water content the liquid fraction increases too. One possible conclusion is that bound water changes the conformations of macromolecular structures with increasing water content. Such a way the conditions for storing of liquid water and for active biological function of biomolecular structures may be produced. (author)

  16. 1H-detected solid-state NMR of proteins entrapped in bioinspired silica: a new tool for biomaterials characterization

    Ravera, Enrico; Cerofolini, Linda; Martelli, Tommaso; Louka, Alexandra; Fragai, Marco; Luchinat, Claudio

    2016-06-01

    Proton-detection in solid-state NMR, enabled by high magnetic fields (>18 T) and fast magic angle spinning (>50 kHz), allows for the acquisition of traditional 1H-15N experiments on systems that are too big to be observed in solution. Among those, proteins entrapped in a bioinspired silica matrix are an attractive target that is receiving a large share of attention. We demonstrate that 1H-detected SSNMR provides a novel approach to the rapid assessment of structural integrity in proteins entrapped in bioinspired silica.

  17. High-field 1H NMR microscopy for fundamental biophysical research

    This work has a biophysical background and uses different examples to demonstrate the practical applicability of NMR-Microscopy in the medical and biological sector. Therefore, the different projects are feasibility studies which are used to compare the possibilities and advantages of NMR-Microscopy with other, established examination techniques. In detail, using MR-Microscopy, different living and fixed biological samples have been visualized non-invasively with high spatial resolution. The specific purpose of the studies ranged from the visualization of the invasion of tumor-spheroids into cell aggregates using T2 parameter maps (time constant of the spin-spin relaxation) to the three-dimensional display of the honey bee brain in the intact head capsule and the non-invasive visualization of the anatomy of prenatal dolphins. For all these projects, the non-invasive character of MR-experiments was of utmost importance. The tumor invasion was not to be disturbed by the measurements, the bee brain should be visualized as close to its true natural shape as possible and the examined dolphins represent rare museum specimens which should not be destroyed. The different samples were all imaged with the best possible spatial resolution which was either limited by the necessary signal-to-noise ratio (SNR) or the available scan time. In order to resolve single details and fine structures in the images, it was necessary to optimize the SNR as well as the contrast-to-noise ratio. To guarantee the necessary SNR, the measurements were performed on high field MR-spectrometers with resonance frequencies of 500 and 750 MHz

  18. Spectroscopic effects in {sup 1}H and {sup 13}C NMR spectra of 4,4`-di-substituted 3,3`-diquinolines sulfides; Efekty spektroskopowe w widmach {sup 1}H i {sup 13}C NMR 4,4`-dwupodstawionych sulfidow 3,3` dichinolinylowych

    Pluta, K. [Katedra i Zaklad Chemii Organicznej, Slaska Akademia Medyczna, Sosnowiec (Poland)

    1994-12-31

    The {sup 1}H and {sup 13}C NMR spectra of 4,4`-disubstituted sulfides of 3,3`-quinolines have been studied in CDCl{sub 3} solutions. The observed spectroscopic effects have been interpreted in terms of molecule structure and configuration. The factors being responsible for the value of spectroscopic effects have been discussed. 11 refs, 3 tabs.

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

    Kaski Kimmo

    2007-05-01

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

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

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

    2013-01-01

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

  1. Unified and isomer-specific NMR metabolomics database for the accurate analysis of (13)C-(1)H HSQC spectra.

    Bingol, Kerem; Li, Da-Wei; Bruschweiler-Li, Lei; Cabrera, Oscar A; Megraw, Timothy; Zhang, Fengli; Brüschweiler, Rafael

    2015-02-20

    A new metabolomics database and query algorithm for the analysis of (13)C-(1)H HSQC spectra is introduced, which unifies NMR spectroscopic information on 555 metabolites from both the Biological Magnetic Resonance Data Bank (BMRB) and Human Metabolome Database (HMDB). The new database, termed Complex Mixture Analysis by NMR (COLMAR) (13)C-(1)H HSQC database, can be queried via an interactive, easy to use web interface at http://spin.ccic.ohio-state.edu/index.php/hsqc/index . Our new HSQC database separately treats slowly exchanging isomers that belong to the same metabolite, which permits improved query in cases where lowly populated isomers are below the HSQC detection limit. The performance of our new database and query web server compares favorably with the one of existing web servers, especially for spectra of samples of high complexity, including metabolite mixtures from the model organisms Drosophila melanogaster and Escherichia coli. For such samples, our web server has on average a 37% higher accuracy (true positive rate) and a 82% lower false positive rate, which makes it a useful tool for the rapid and accurate identification of metabolites from (13)C-(1)H HSQC spectra at natural abundance. This information can be combined and validated with NMR data from 2D TOCSY-type spectra that provide connectivity information not present in HSQC spectra. PMID:25333826

  2. Unified and Isomer-Specific NMR Metabolomics Database for the Accurate Analysis of 13C–1H HSQC Spectra

    2015-01-01

    A new metabolomics database and query algorithm for the analysis of 13C–1H HSQC spectra is introduced, which unifies NMR spectroscopic information on 555 metabolites from both the Biological Magnetic Resonance Data Bank (BMRB) and Human Metabolome Database (HMDB). The new database, termed Complex Mixture Analysis by NMR (COLMAR) 13C–1H HSQC database, can be queried via an interactive, easy to use web interface at http://spin.ccic.ohio-state.edu/index.php/hsqc/index. Our new HSQC database separately treats slowly exchanging isomers that belong to the same metabolite, which permits improved query in cases where lowly populated isomers are below the HSQC detection limit. The performance of our new database and query web server compares favorably with the one of existing web servers, especially for spectra of samples of high complexity, including metabolite mixtures from the model organisms Drosophila melanogaster and Escherichia coli. For such samples, our web server has on average a 37% higher accuracy (true positive rate) and a 82% lower false positive rate, which makes it a useful tool for the rapid and accurate identification of metabolites from 13C–1H HSQC spectra at natural abundance. This information can be combined and validated with NMR data from 2D TOCSY-type spectra that provide connectivity information not present in HSQC spectra. PMID:25333826

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

    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

  4. Solution NMR Experiment for Measurement of (15)N-(1)H Residual Dipolar Couplings in Large Proteins and Supramolecular Complexes.

    Eletsky, Alexander; Pulavarti, Surya V S R K; Beaumont, Victor; Gollnick, Paul; Szyperski, Thomas

    2015-09-01

    NMR residual dipolar couplings (RDCs) are exquisite probes of protein structure and dynamics. A new solution NMR experiment named 2D SE2 J-TROSY is presented to measure N-H RDCs for proteins and supramolecular complexes in excess of 200 kDa. This enables validation and refinement of their X-ray crystal and solution NMR structures and the characterization of structural and dynamic changes occurring upon complex formation. Accurate N-H RDCs were measured at 750 MHz (1)H resonance frequency for 11-mer 93 kDa (2)H,(15)N-labeled Trp RNA-binding attenuator protein tumbling with a correlation time τc of 120 ns. This is about twice as long as that for the most slowly tumbling system, for which N-H RDCs could be measured, so far, and corresponds to molecular weights of ∼200 kDa at 25 °C. Furthermore, due to the robustness of SE2 J-TROSY with respect to residual (1)H density from exchangeable protons, increased sensitivity at (1)H resonance frequencies around 1 GHz promises to enable N-H RDC measurement for even larger systems. PMID:26293598

  5. Improving the efficiency of quantitative (1)H NMR: an innovative external standard-internal reference approach.

    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

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

    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.

  7. {sup 1} H NMR spectral analysis bromine and iodine from o-xylene by simulation; Analise de espectros de RMN de {sup 1} H de bromo e iodo derivados de o-xileno por simulacao

    Lopes, Julio C.D. [Minas Gerais Univ., Belo Horizonte, MG (Brazil). Dept. de Quimica; Arruda Campos, Ivan P. de; Rezende, Daisy de B.; Malta Junior, Jose S.; Alcantara, M. Regina [Sao Paulo Univ., SP (Brazil). Inst. de Quimica; Ebeling, Guenter [Rio Grande do Sul Univ., Porto Alegre, RS (Brazil). Inst. de Quimica

    1995-12-31

    The increasing interest on benzyl halides and related molecules for photochemistry is due to its flexibility as precursors. However, standard NMR data for this compounds haven`t been found in the literature. In order to supply this lack, this work has presented NMR data for some of them. {sup 1} H NMR spectra were analysed using a spectral simulation program, LAOCN9 program. The results were discussed widely 15 refs., 3 figs., 2 tabs.

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

    Eun-Young Won

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

  9. From simple liquids to polymers: Dynamics revealed by field cycling {sup 1}H NMR

    Herrmann, Axel; Abou Elfadl, Azza; Meier, Roman; Kruk, Danuta; Novikov, Vladimir N.; Roessler, Ernst A. [Experimentalphysik II, Universitaet Bayreuth (Germany)

    2010-07-01

    We apply field cycling NMR to study the crossover from glassy through Rouse to reptation dynamics in series of different linear polymers (PB, PDMS, PPO, PI) with molecular weight M ranging from the low-M limit (simple liquid) to the high-M limit. Dispersion data of the spin-lattice relaxation time T{sub 1}({omega}) are transformed to the susceptibility representation {chi} {sup parallel} ({omega}{tau}{sub s})={omega}/T{sub 1}, and using frequency-temperature superposition master curves {chi} {sup parallel} ({omega}{tau}{sub s}) ({tau}{sub s}:=segmental correlation time) are constructed which reflect spectral contributions from glassy as well as polymer specific dynamics. We are able to cover six decades at {omega}{tau}{sub s}<1 allowing to monitor in detail the emergence of polymer specific relaxation contributions. Transforming the master curves into the time domain yields the segmental reorientational correlation function which we follow over six decades in amplitude. From this the order parameter as well as bond-vector correlation function are derived. Comparison with theoretical predictions by the tube-reptation model as well as renormalized Rouse theory reveals significant discrepancies whereas good agreement is found with Monte Carlo simulations. We conclude that the crossover to entanglement dynamics appears to be highly protracted. This is confirmed by accompanying measurements of dielectric normal mode spectra.

  10. From simple liquids to polymers: Dynamics revealed by field cycling 1H NMR

    We apply field cycling NMR to study the crossover from glassy through Rouse to reptation dynamics in series of different linear polymers (PB, PDMS, PPO, PI) with molecular weight M ranging from the low-M limit (simple liquid) to the high-M limit. Dispersion data of the spin-lattice relaxation time T1(ω) are transformed to the susceptibility representation χ parallel (ωτs)=ω/T1, and using frequency-temperature superposition master curves χ parallel (ωτs) (τs:=segmental correlation time) are constructed which reflect spectral contributions from glassy as well as polymer specific dynamics. We are able to cover six decades at ωτs<1 allowing to monitor in detail the emergence of polymer specific relaxation contributions. Transforming the master curves into the time domain yields the segmental reorientational correlation function which we follow over six decades in amplitude. From this the order parameter as well as bond-vector correlation function are derived. Comparison with theoretical predictions by the tube-reptation model as well as renormalized Rouse theory reveals significant discrepancies whereas good agreement is found with Monte Carlo simulations. We conclude that the crossover to entanglement dynamics appears to be highly protracted. This is confirmed by accompanying measurements of dielectric normal mode spectra.

  11. 1H NMR structural characterization of a recombinant kringle 2 domain from human tissue-type plasminogen activator

    The kringle 2 domain of human tissue-type plasminogen activator (t-PA) has been characterized via 1H NMR spectroscopy at 300 and 620 MHz. The experiments were performed on the isolated domain obtained by expression of the 174-263 portion of t-PA in Escherichia coli. The spectrum of t-Pa kringle 2 is characteristic of a globular structure and shows overall similarity to that of the plasminogen (PGN) kringle 4. Spectral comparison with human and bovine PGN kringle 4 identified side-chain resonances from Leu46, which afford a fingerprint of kringle folding, and from most of the aromatic ring spin systems. Ligand-binding studies confirm that t-PA kringle 2 binds L-lysine with an association constant Ka ∼ 11.9 mM-1. The data indicate that homologous or conserved residues relative to those that compose the lysine-binding sites of PGN kringles 1 and 4 are involved in the binding of L-lysine to t-PA kringle 2. These include Tyr36 and, within the kringle inner loop, Trp62, His64, Trp72, and Tyr74. Several labile NH protons of t-PA kringle 2 exhibit retarded H-exchange kinetics, requiring more than a week in 2H2O for full deuteration in the presence of L-lysine at 37 degree C. This reveals that kringle 2 is endowed with a compact, dynamically stable conformation. Proton Overhauser experiments in 1H2O, centered on well-resolved NH resonances between 9.8 and 12 ppm, identify signals arising from the His48a imidazole NH3 proton and the three Trp indole NH1 protons. Overall, the data indicate a highly structured conformation for the recombinant t-PA kringle 2 that is closely related to that of the previously investigated PGN kringles 1, 4, and 5

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

    Culf Adrian

    2011-10-01

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

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

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

    2016-05-30

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

  14. {sup 1}H NMR-based metabolic profiling reveals inherent biological variation in yeast and nematode model systems

    Szeto, Samuel S. W.; Reinke, Stacey N.; Lemire, Bernard D., E-mail: bernard.lemire@ualberta.ca [University of Alberta, Department of Biochemistry, School of Molecular and Systems Medicine (Canada)

    2011-04-15

    The application of metabolomics to human and animal model systems is poised to provide great insight into our understanding of disease etiology and the metabolic changes that are associated with these conditions. However, metabolomic studies have also revealed that there is significant, inherent biological variation in human samples and even in samples from animal model systems where the animals are housed under carefully controlled conditions. This inherent biological variability is an important consideration for all metabolomics analyses. In this study, we examined the biological variation in {sup 1}H NMR-based metabolic profiling of two model systems, the yeast Saccharomyces cerevisiae and the nematode Caenorhabditis elegans. Using relative standard deviations (RSD) as a measure of variability, our results reveal that both model systems have significant amounts of biological variation. The C. elegans metabolome possesses greater metabolic variance with average RSD values of 29 and 39%, depending on the food source that was used. The S. cerevisiae exometabolome RSD values ranged from 8% to 12% for the four strains examined. We also determined whether biological variation occurs between pairs of phenotypically identical yeast strains. Multivariate statistical analysis allowed us to discriminate between pair members based on their metabolic phenotypes. Our results highlight the variability of the metabolome that exists even for less complex model systems cultured under defined conditions. We also highlight the efficacy of metabolic profiling for defining these subtle metabolic alterations.

  15. 1H NMR-based metabolic profiling reveals inherent biological variation in yeast and nematode model systems

    The application of metabolomics to human and animal model systems is poised to provide great insight into our understanding of disease etiology and the metabolic changes that are associated with these conditions. However, metabolomic studies have also revealed that there is significant, inherent biological variation in human samples and even in samples from animal model systems where the animals are housed under carefully controlled conditions. This inherent biological variability is an important consideration for all metabolomics analyses. In this study, we examined the biological variation in 1H NMR-based metabolic profiling of two model systems, the yeast Saccharomyces cerevisiae and the nematode Caenorhabditis elegans. Using relative standard deviations (RSD) as a measure of variability, our results reveal that both model systems have significant amounts of biological variation. The C. elegans metabolome possesses greater metabolic variance with average RSD values of 29 and 39%, depending on the food source that was used. The S. cerevisiae exometabolome RSD values ranged from 8% to 12% for the four strains examined. We also determined whether biological variation occurs between pairs of phenotypically identical yeast strains. Multivariate statistical analysis allowed us to discriminate between pair members based on their metabolic phenotypes. Our results highlight the variability of the metabolome that exists even for less complex model systems cultured under defined conditions. We also highlight the efficacy of metabolic profiling for defining these subtle metabolic alterations.

  16. Vibrational spectroscopic studies, NMR, HOMO-LUMO, NLO and NBO analysis of 1-(2-nitrobenzoyl)-3,5-diphenyl-4,5-dihydro-1H-pyrazole with use X-ray diffractions and DFT calculations

    Demir, Sibel; Tinmaz, Feyza; Dege, Necmi; Ilhan, Ilhan Ozer

    2016-03-01

    The crystal and molecular structure of the title compound, 1-(2-nitrobenzoyl)-3,5-diphenyl-4,5-dihydro-1H-pyrazole, was reported and confirmed by single crystal X-ray diffraction and spectroscopic data. The structure, geometry optimization, vibrational frequencies and nuclear magnetic resonance were also investigated. Stability of the molecule arising from hyperconjugative interactions and charge delocalisation was analysed using natural bond orbital analysis. The results show that charge in electron density (ED) in the σ∗ and π∗ antibonding orbitals and second-order delocalisation energies E(2) confirms the occurrence of intramolecular charge transfer within the molecule. Satisfactory theoretical aspects were made for the stable conformer of the molecule using density functional theory DFT-B3LYP methods with the 6-311G++(d,p) basis set.

  17. 1H NMR structural and thermodynamical analysis of the hetero-association of daunomycin and novatrone in aqueous solution

    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.

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

    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

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

    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.

  20. {sup 1}H NMR metabolomics identification of markers of hypoxia-induced metabolic shifts in a breast cancer model system

    Weljie, Aalim M., E-mail: aweljie@ucalgary.ca [University of Calgary, Department of Biological Sciences (Canada); Bondareva, Alla [Department of Comparative Biology and Experimental Medicine (Canada); Zang, Ping [University of Calgary, Department of Chemistry (Canada); Jirik, Frank R. [McCaig Institute for Bone and Joint Health, Department of Biochemistry and Molecular Biology (Canada)

    2011-04-15

    Hypoxia can promote invasive behavior in cancer cells and alters the response to therapeutic intervention as a result of changes in the expression many genes, including genes involved in intermediary metabolism. Although metabolomics technologies are capable of simultaneously measuring a wide range of metabolites in an untargeted manner, these methods have been relatively under utilized in the study of cancer cell responses to hypoxia. Thus, {sup 1}H NMR metabolomics was used to examine the effects of hypoxia in the MDA-MB-231 human breast cancer cell line, both in vitro and in vivo. Cell cultures were compared with respect to their metabolic responses during growth under either hypoxic (1% O{sub 2}) or normoxic conditions. Orthogonal partial least squares discriminant analysis (OPLS-DA) was used to identify a set of metabolites that were responsive to hypoxia. Via intracardiac administration, MDA-MB-231 cells were also used to generate widespread metastatic disease in immuno-compromised mice. Serum metabolite analysis was conducted to compare animals with and without a large tumor burden. Intriguingly, using a cross-plot of the OPLS loadings, both the in vitro and in vivo samples yielded a subset of metabolites that were significantly altered by hypoxia. These included primarily energy metabolites and amino acids, indicative of known alterations in energy metabolism, and possibly protein synthesis or catabolism. The results suggest that the metabolite pattern identified might prove useful as a marker for intra-tumoral hypoxia.

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

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

  2. 1H NMR metabolomics identification of markers of hypoxia-induced metabolic shifts in a breast cancer model system

    Hypoxia can promote invasive behavior in cancer cells and alters the response to therapeutic intervention as a result of changes in the expression many genes, including genes involved in intermediary metabolism. Although metabolomics technologies are capable of simultaneously measuring a wide range of metabolites in an untargeted manner, these methods have been relatively under utilized in the study of cancer cell responses to hypoxia. Thus, 1H NMR metabolomics was used to examine the effects of hypoxia in the MDA-MB-231 human breast cancer cell line, both in vitro and in vivo. Cell cultures were compared with respect to their metabolic responses during growth under either hypoxic (1% O2) or normoxic conditions. Orthogonal partial least squares discriminant analysis (OPLS-DA) was used to identify a set of metabolites that were responsive to hypoxia. Via intracardiac administration, MDA-MB-231 cells were also used to generate widespread metastatic disease in immuno-compromised mice. Serum metabolite analysis was conducted to compare animals with and without a large tumor burden. Intriguingly, using a cross-plot of the OPLS loadings, both the in vitro and in vivo samples yielded a subset of metabolites that were significantly altered by hypoxia. These included primarily energy metabolites and amino acids, indicative of known alterations in energy metabolism, and possibly protein synthesis or catabolism. The results suggest that the metabolite pattern identified might prove useful as a marker for intra-tumoral hypoxia.

  3. 1H NMR relaxometry in the TGBA* and TGBC*phases

    Domenici, V.; Gradišek, A.; Apih, T.; Hamplová, Věra; Novotná, Vladimíra; Sebastião, P.J.

    2016-01-01

    Roč. 49, č. 1 (2016), 17-27. ISSN 0015-0193 Grant ostatní: AVČR(CZ) M100101204 Institutional support: RVO:68378271 Keywords : Ferroelectric liquid crystal * chiral liquid crystals * molecular dynamics * NMR * twist grain boundary phases * spin-lattice Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 0.469, year: 2014

  4. Microcomputer utilization for comparison of 1H-NMR spectra with data base standards

    A new computacional technique for the storage of spectrometric data of natural products listed in the literature and its comparison with data of new compounds isolated as natural products is described here. The programs allow a correlation of two spectra by inverting one relative to the other. The programs again permit the comparison of two NMR spectra in different frequencies. (author)

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

    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.

  6. Rapid solid-state NMR of deuterated proteins by interleaved cross-polarization from 1H and 2H nuclei

    Bjerring, Morten; Paaske, Berit; Oschkinat, Hartmut; Akbey, Ümit; Nielsen, Niels Chr.

    2012-01-01

    We present a novel sampling strategy, interleaving acquisition of multiple NMR spectra by exploiting initial polarization subsequently from 1H and 2H spins, taking advantage of their different T1 relaxation times. Different 1H- and 2H-polarization based spectra are in this way simultaneously recorded improving either information content or sensitivity by adding spectra. The so-called Relaxation-optimized Acquisition of Proton Interleaved with Deuterium (RAPID) 1H → 13C/ 2H → 13C CP/MAS multiple-acquisition method is demonstrated by 1D and 2D experiments using a uniformly 2H, 15N, 13C-labeled α-spectrin SH3 domain sample with all or 30% back-exchanged labile 2H to 1H. It is demonstrated how 1D 13C CP/MAS or 2D 13C- 13C correlation spectra initialized with polarization from either 1H or 2H may be recorded simultaneously with flexibility to be added or used individually for spectral editing. It is also shown how 2D 13C- 13C correlation spectra may be recorded interleaved with 2H- 13C correlation spectra to obtain 13C- 13C correlations along with information about dynamics from 2H sideband patterns.

  7. Interfaces in polymer nanocomposites - An NMR study

    Böhme, Ute; Scheler, Ulrich

    2016-03-01

    Nuclear Magnetic Resonance (NMR) is applied for the investigation of polymer nanocomposites. Solid-state NMR is applied to study the modification steps to compatibilize layered double hydroxides with non-polar polymers. 1H relaxation NMR gives insight on the polymer dynamics over a wide range of correlation times. For the polymer chain dynamics the transverse relaxation time T2 is most suited. In this presentation we report on two applications of T2 measurements under external mechanical stress. In a low-field system relaxation NMR studies are performed in-situ under uniaxial stress. High-temperature experiments in a Couette cell permit the investigation of the polymer dynamics in the melt under shear flow.

  8. 基于1H NMR 技术的乳热奶牛血清代谢组学分析%1H NMR-based Serum Metabolomics Analysis of Dairy Cows with Milk Fever

    孙雨航; 许楚楚; 李昌盛; 夏成; 徐闯; 吴凌; 张洪友

    2015-01-01

    with differences in performance were filtered out. [Result] In this study, serum metabolic profiles and loading plot from MF group and control group were successfully obtained. PCA result showed that all samples were within 95% confidence interval, without excluding, and the contribution rate of the primary component was low, in which PC1 = 26.2%, PC2 = 16.7%, the different variables between the two groups can not be selected. OSC-PLS-DA result showed that the five orthogonal signal corrections were conducted to remove those components which displayed no significant grouping and maximize the differences between groups. Compared with the healthy control group, 9 differentially expressed serum metabolites were screened, which included 4 upregulated compounds, such as β- hydroxybutyrate, acetone, pyruvate and lysine, 5 downregulated compounds, such as glucose, alanine, glycerol, creatine phosphate and gamma-Aminobutyrate. They were mostly sugars and amino acids, formed an energy conversion network diagram between each, involved in various energy metabolism pathways in the body. Of which, the more specific metabolites, such as creatine phosphate, directly provided energy for the body, decrease of which may be associated with the performance of muscle weakness and paralysis on the cow. In addition, the gamma-Aminobutyrate(GABA) of cows with MF was decreased, and had clinical manifestations of depression, even coma, which was coincided with human performance of depression, but the relationship between decrease of GABA spirit of the cow and MF needs to be further confirmed by investigators. [Conclusion] 1H NMR technique can be applied to screen small molecule metabolites in cow serum with differences in quantity and the difference was significant. In this study, metabolites in cows with MF showed some pathological features of negative energy balance and fat mobilization, suggesting that MF is associated with energy metabolism disorders.

  9. 1H NMR relaxometry as an indicator of setting and water depletion during cement hydration

    Proton nuclear magnetic resonance relaxometry has been used to detect setting and microstructure evolution during cement hydration. NMR measurements were performed since casting, during setting and until hardening (from 0 to 3 days). The mobility of water molecules was assessed by an analysis focused on the diagram of longitudinal relaxation time T1 generated by an Inversion Recovery sequence. The initial stiffening of the solid network was identified by an analysis of the relaxation rate 1/T1. The kinetics of water depletion was investigated by using a simple one-pulse acquisition sequence. In parallel, conventional techniques (Vicat needle and temperature monitoring), as well as numerical simulations of hydration, were used to complement and validate these NMR results. Cement pastes and mortars with different water-to-cement ratios made of grey or white OPCs were tested. Furthermore, the effects of the addition of sand, super-plasticizer and silica fume on the hydration kinetics were investigated

  10. {sup 1}H NMR relaxometry as an indicator of setting and water depletion during cement hydration

    Wang, Biyun [Université Paris-Est, IFSTTAR, Materials Department, F-75732, Paris (France); Université Paris-Est, Laboratoire Navier, Ecole des Ponts ParisTech, IFSTTAR, CNRS, F-77455 Marne-la-Vallée (France); Faure, Paméla [Université Paris-Est, Laboratoire Navier, Ecole des Ponts ParisTech, IFSTTAR, CNRS, F-77455 Marne-la-Vallée (France); Thiéry, Mickaël, E-mail: mickael.thiery@ifsttar.fr [Université Paris-Est, IFSTTAR, Materials Department, F-75732, Paris (France); Baroghel-Bouny, Véronique [Université Paris-Est, IFSTTAR, Materials Department, F-75732, Paris (France)

    2013-03-15

    Proton nuclear magnetic resonance relaxometry has been used to detect setting and microstructure evolution during cement hydration. NMR measurements were performed since casting, during setting and until hardening (from 0 to 3 days). The mobility of water molecules was assessed by an analysis focused on the diagram of longitudinal relaxation time T{sub 1} generated by an Inversion Recovery sequence. The initial stiffening of the solid network was identified by an analysis of the relaxation rate 1/T{sub 1}. The kinetics of water depletion was investigated by using a simple one-pulse acquisition sequence. In parallel, conventional techniques (Vicat needle and temperature monitoring), as well as numerical simulations of hydration, were used to complement and validate these NMR results. Cement pastes and mortars with different water-to-cement ratios made of grey or white OPCs were tested. Furthermore, the effects of the addition of sand, super-plasticizer and silica fume on the hydration kinetics were investigated.

  11. The use of dynamic nuclear polarization in 1H and 13C solid state NMR

    The Dynamic Nuclear Polarization (DNP) effect is used at room temperature in combination with 13C NMR. Due to the low natural abundance of 13C spins (1%) the signal is very weak, but when the DNP effect is used the 13C signal can be enhanced and therefore the number of scans and the measuring time considerably reduced. The theory is presented and the experimental set-up is described. Experiments on polystyrene, artificially doped with free radicals are described and it is examined whether the theory of the DNP effect can be used in a quantitative way. Applications of the use of the DNP effect in 13C NMR are shown. Excellent spectra are presented of artificial and natural diamonds, possibly to be used for diamond characterization purposes. 161 refs.; 61 figs.; 3 tabs

  12. 31P and 1H NMR studies of the structure of enzyme-bound substrate complexes of lobster muscle arginine kinase: Relaxation measurements with Mn(II) and Co(II)

    The paramagnetic effects of Mn(II) and Co(II) on the spin-lattice relaxation rates of 31P nuclei of ATP and ADP and of Mn(II) on the spin-lattice relaxation rate of the δ protons of arginine bound to arginine kinase from lobster tail muscle have been measured. Temperature variation of 31P relaxation rates in E-MnADP and E-MnATP yields activation energies (ΔE) in the range 6-10 kcal/mol. Thus, the 31P relaxation rates in these complexes are exchange limited and cannot provide structural information. However, the relaxation rates in E-CoADP and E-CoATP exhibit frequency dependence and ΔE values in the range 1-2 kcal/mol; i.e., these rates depend upon 31P-Co(II) distances. These distances were calculated to be in the range 3.2-4.5 angstrom, appropriate for direct coordination between Co(II) and the phosphoryl groups. The paramagnetic effect of Mn(II) on the 1H spin-lattice relaxation rate of the δ protons of arginine in the E-MnADP-Arg complex was also measured at three frequencies. From the frequency dependence of the relaxation rate an effective τC of 0.6 ns has also been calculated, which is most likely to be the electron spin relaxation rate (τS1) for Mn(II) in this complex. The distance estimated on the basis of the reciprocal sixth root of the average relaxation rate of the δ protons was 10.9 ± 0.3 angstrom

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

    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

  14. A sup 1 H nuclear magnetic resonance study of structural and organisational changes in the cell

    Tunnah, S K

    2000-01-01

    Increasing importance is being placed on understanding the role of membrane lipids in many different areas of biochemistry. It is of interest to determine what interactions may occur between membrane lipids and drug species. Furthermore, an increasing body of evidence suggests that membrane lipids are involved in the pathology of numerous diseases such as rheumatoid arthritis, cancer and HIV. Clearly, the more information available on the mechanisms involved in diseases, the greater the potential for identifying a cure or even a prevention. sup 1 H nuclear magnetic resonance (NMR) spectroscopy was used to study the alterations in membrane lipid organisation and structure in intact, viable cultured cells. Changes in the sup 1 H NMR spectra and the spin-lattice relaxation measurements of the human K562 and the rat FRTL-5 cell lines were observed on the addition of the fatty acid species: triolein, evening primrose oil, arachidonic acid and ITF 1779. Results indicate that the membrane lipids are reorganised to a...

  15. Nano-mole scale sequential signal assignment by 1 H-detected protein solid-state NMR

    Wang, Songlin

    2015-01-01

    We present a 3D 1H-detected solid-state NMR (SSNMR) approach for main-chain signal assignments of 10-100 nmol of fully protonated proteins using ultra-fast magic-angle spinning (MAS) at ∼80 kHz by a novel spectral-editing method, which permits drastic spectral simplification. The approach offers ∼110 fold time saving over a traditional 3D 13C-detected SSNMR approach. This journal is © The Royal Society of Chemistry 2015.

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

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

    2003-01-01

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

  17. Stanovení složení automobilových paliv metodami 1H NMR spektroskopie

    Trejtnarová, Hana

    Praha : Vysoká škola chemicko-technologická, 2009 - (Černý, J.), s. 139-146 ISBN 978-80-7080-715-6. [Konference s mezinárodní účastí REOTRIB 2009 Kvalita paliv a maziv /15./. Velké Losiny (CZ), 27.05.2009-29.05.2009] R&D Projects: GA AV ČR IAA300460804 Institutional research plan: CEZ:AV0Z30460519 Keywords : 1H NMR * gasoline * diesel fuel Subject RIV: CB - Analytical Chemistry, Separation

  18. Complete assignment of lysine resonances in 1H NMR spectra of proteins as probes of surface structure and dynamics

    A strategy is presented for complete identification of 1H spin systems of lysine residues using sophisticated 2D NMR experiments. Relayed and remote connectivities within each spin system are determined for spin subsystems based at the backbone amide and Cε proton resonances. When complete spin system identification is combined with sequence-specific assignment, protein surface structure and dynamics can be probed in a site-specific manner. The interaction between the five lysine residues of French bean plastocyanin and a model redox partner Cr(CN)63- has been examined using this approach. 12 refs.; 3 figs.; 1 table

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

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

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

    2013-01-01

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

  1. Planar coupled water pair cluster in disordered solids: Theory of the 1H NMR dipolar Hamiltonian

    The proton NMR dipolar interaction Hamiltonian is set up for the model of planar coupled water pair clusters in disordered solids. The Hamiltonian, when analytically solved, leads to interesting predictions of structured dipolar lineshapes when (a) the four protons are tightly coupled and (b) when the dipolar interaction is modulated by water molecules flipping between fixed directions. Detailed features of the line positions and intensities are worked out for both these models, and a suitable formulation is presented for simulating powder lineshapes in a variety of experimental situations. (author). 14 refs., 6 figs

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

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

    2016-08-01

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

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

    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

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

    Ross, J.B.A.; Schwartz, G.P.; Laws, W.R. (Mount Sinai, New York, NY (United States)); Wyssbrod, H.R.; Porter, R.A. (Univ. of Louisville, KY (United States)); Michaels, C.A. (Swarthmore Coll., PA (United States))

    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.

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

    Shadwick, Steven R.; Mohan, Ram S.

    1999-08-01

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

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

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

  7. Efficient 1H-NMR Quantitation and Investigation of N-Acetyl-D-glucosamine (GlcNAc and N,N'-Diacetylchitobiose (GlcNAc2 from Chitin

    Huey-Lang Yang

    2011-09-01

    Full Text Available A quantitative determination method of N-acetyl-D-glucosamine (GlcNAc and N,N'-diacetylchitobiose (GlcNAc2 is proposed using a proton nuclear magnetic resonance experiment. N-acetyl groups of GlcNAc and (GlcNAc2 are chosen as target signals, and the deconvolution technique is used to determine the concentration of the corresponding compound. Compared to the HPLC method, 1H-NMR spectroscopy is simple and fast. The method can be used for the analysis of chitin hydrolyzed products with real-time analysis, and for quantifying the content of products using internal standards without calibration curves. This method can be used to quickly evaluate chitinase activity. The temperature dependence of 1H-NMR spectra (VT-NMR is studied to monitor the chemical shift variation of acetyl peak. The acetyl groups of products are involved in intramolecular H-bonding with the OH group on anomeric sites. The rotation of the acetyl group is closely related to the intramolecular hydrogen bonding pattern, as suggested by the theoretical data (molecular modeling.

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

    Lingling Wang

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

  9. Relationships between 1H NMR Relaxation Data and Some Technological Parameters of Meat: A Chemometric Approach

    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.

  10. Nano and sub-nano multiscale porosity formation and other features revealed by 1H NMR relaxometry during cement hydration.

    Bortolotti, Villiam; Brizi, Leonardo; Brown, Robert J S; Fantazzini, Paola; Mariani, Manuel

    2014-09-16

    Cement hydration occurs when water is added to cement powder, leading to the formation of crystalline products like Portlandite and the quasi-amorphous, poorly crystalline, calcium silicate hydrate (C-S-H) gel. Despite its importance in determining the final properties of the cement, many models exist for the nano and sub-nano level organization of this "liquid stone." (1)H NMR relaxometry in White Portland Cement paste during hydration allowed us to monitor the formation and evolution of the multiscale porosity of the cement, with the formation of structures at nano and sub-nano levels of C-S-H gel (calcium silicate interlayer water, water in small and large gel pores) along with three low-mobility (1)H pools, identified as (1)H nuclei in C-S-H layers, likely belonging to OH groups, with (1)H nuclei in Portlandite, and in crystal water of Ettringite. By assuming these assignments, our data allowed us to compute the distances of pairs of (1)H nuclei in Portlandite and in crystal water ((1.9 ± 0.2) Å and (1.6 ± 0.1) Å, respectively), consistent with the known values of these distances. The picture of the porous structure at nano and sub-nano levels emerging from our results is consistent with the Jennings colloidal model for C-S-H gel. Moreover, the constant values observed during hydration of parameters extracted from our data analysis strongly support that model, being compatible with the picture of C-S-H gel developing in comparable-sized clumps of the same composition, but not easily interpretable by models proposing quasi continuous sheets of C-S-H layers. PMID:25152010

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

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

    2004-01-01

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

  12. DNA oligonucleotide conformations: high resolution NMR studies

    The present work describes a DNA double-helix model, which is well comparable with the models derived from fibre-diffraction studies. The model has a mononucleotide repeat with torsion angles in accordance with average geometries as derived from 1H NMR studies. Special attention was paid to reduce the number of short H-H nonbonding contacts, which are abundantly present in the 'classical' fibre-diffraction models. Chapter 3 describes the first complete assignment of a 1H NMR spectrum of a DNA tetramer, d(TAAT). Preliminary conformational data derived from the spectral parameters recorded at 27 0C are given. A more detailed analysis employing temperature-dependence studies is given in Chapter 4. (Auth.)

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

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

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

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

    1991-04-09

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

  15. A sample preparation protocol for 1H nuclear magnetic resonance studies of water-soluble metabolites in blood and urine.

    Sheedy, John R; Ebeling, Peter R; Gooley, Paul R; McConville, Malcolm J

    2010-03-15

    We describe a general protocol for preparing protein-containing biofluids for (1)H nuclear magnetic resonance (NMR) metabolomic studies. In this protocol, untreated samples are diluted in deuterated solvents to precipitate proteins and recover metabolites quantitated relative to standard reference compounds such as 3-trimethylsilylpropionic acid (TSP) and 2,2-dimethyl-2-silapentane-5-sulfonic acid (DSS). The efficacy of this protocol was tested using a bovine serum albumin/metabolite mix and human serum samples. This sample preparation method can be readily applied to any protein-containing biofluid for (1)H NMR studies. PMID:19941831

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

    Abdul Jameel, Abdul Gani

    2016-04-22

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

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

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

    2014-01-01

    A new impurity was detected during high performance liquid chromatographic (HPLC) analysis of eslicarbazepine acetate active pharmaceutical ingredient. The structure of unknown impurity was postulated based on liquid chromatography mass spectrometry using electrospray ionization and ion trap analyzer (LC/ESI–IT/MS) analysis. Proposed structure of impurity was unambiguously confirmed by synthesis followed by characterization using 1H, 13C nuclear magnetic resonance spectrometry (NMR), 1H–1H co...

  18. 31 P and two-dimensional 31 P-1 H NMR analysis of brain extracts in animal models of multiple sclerosis

    We report here the study of the brain phospholipid content of normal and myelin deficient (md) rats, which develop a physiological impairment at about 15-20 days, and die at 20-25 days of age. The aim is to gain insights into the lipid composition of developing brain, and also to reveal of there exist some early event in the phospholipid metabolism that produces a pathological condition similar to the formation of demyelination plaques in multiple sclerosis. 31 P NMR allows one to detect phospholipids selectively out of a complex lipid mixture in crude extracts. Two-dimensional (2D) 31 P-1H NMR with isotropic proton mixing seems to be a superior technique for assignment of phospholipid 31 P resonances. (author)

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

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

  20. Paramagnetic NMR relaxation in polymeric matrixes: sensitivity enhancement and selective suppression of embedded species (1H and 13C PSR filter).

    Fernandez-Megia, Eduardo; Correa, Juan; Novoa-Carballal, Ramon; Riguera, Ricardo

    2007-12-12

    A study of the practical applications of the addition of paramagnetic spin relaxation (PSR) ions to a variety of polymers (PLL, PAA, PGA, PVP, and polysaccharides such as hyaluronic acid, chitosan, mannan, and dextran) in solution (D2O and DMSO-d6) is described. Use of Gd(III), Cu(II), and Mn(II) allows a reduction of up to 500% in the 1H longitudinal relaxation times (T1), and so in the time necessary for recording quantitative NMR spectra (sensitivity enhancement) neither an increase of the spectral line width nor chemical shift changes resulted from addition of any of the PSR agents tested. Selective suppression of the 1H and 13C NMR signals of certain components (low MW molecules and polymers) in the spectrum of a mixture was attained thanks to their different sensitivity [transverse relaxation times (T2)] to Gd(III) (PSR filter). Illustration of this strategy with block copolymers (PGA-g-PEG) and mixtures of polymers and low MW molecules (i.e., lactose-hyaluronic acid, dextran-PAA, PVP-glutamic acid) in 1D and 2D NMR experiments (COSY and HMQC) is presented. In those mixtures where PSR and CPMG filters alone failed in the suppression of certain components (i.e., PVP-mannan-hyaluronic acid) due to their similarity of 1H T2 values and sensitivities to Gd(III), use of the PSR filter in combination with CPMG sequences (PSR-CPMG filter) successfully resulted in the sequential suppression of the components (hyaluronic acid first and then mannan). PMID:18004845

  1. Serum 1H-NMR metabolomic fingerprints of acute-on-chronic liver failure in intensive care unit patients with alcoholic cirrhosis.

    Roland Amathieu

    Full Text Available INTRODUCTION: Acute-on-chronic liver failure is characterized by acute deterioration of liver function in patients with compensated or decompensated, but stable, cirrhosis. However, there is no accurate definition of acute-on-chronic liver failure and physicians often use this term to describe different clinical entities. Metabolomics investigates metabolic changes in biological systems and identifies the biomarkers or metabolic profiles. Our study assessed the metabolomic profile of serum using proton nuclear magnetic resonance ((1H-NMR spectroscopy to identify metabolic changes related to acute-on-chronic liver failure. PATIENTS: Ninety-three patients with compensated or decompensated cirrhosis (CLF group but stable liver function and 30 patients with cirrhosis and hospitalized for the management of an acute event who may be responsible of acute-on-chronic liver failure (ACLF group, were fully analyzed. Blood samples were drawn at admission, and sera were separated and stored at -80°C until (1H-NMR spectral analysis. Using orthogonal projection to latent-structure discriminant analyses, various metabolites contribute to the complete separation between these both groups. RESULTS: The predictability of the model was 0.73 (Q(2 Y and the explained variance was 0.63 (R(2 Y. The main metabolites that had increased signals related to acute-on-chronic liver failure were lactate, pyruvate, ketone bodies, glutamine, phenylalanine, tyrosine, and creatinine. High-density lipids were lower in the ALCF group than in CLF group. CONCLUSION: A serum metabolite fingerprint for acute-on-chronic liver failure, obtained with (1H-NMR, was identified. Metabolomic profiling may aid clinical evaluation of patients with cirrhosis admitted into intensive care units with acute-on-chronic liver failure, and provide new insights into the metabolic processes involved in acute impairment of hepatic function.

  2. A (1H NMR-Based Metabonomic Investigation of Time-Related Metabolic Trajectories of the Plasma, Urine and Liver Extracts of Hyperlipidemic Hamsters.

    Chun-Ying Jiang

    Full Text Available The hamster has been previously found to be a suitable model to study the changes associated with diet-induced hyperlipidemia in humans. Traditionally, studies of hyperlipidemia utilize serum- or plasma-based biochemical assays and histopathological evaluation. However, unbiased metabonomic technologies have the potential to identify novel biomarkers of disease. Thus, to obtain a better understanding of the progression of hyperlipidemia and discover potential biomarkers, we have used a proton nuclear magnetic resonance spectroscopy ((1H-NMR-based metabonomics approach to study the metabolic changes occurring in the plasma, urine and liver extracts of hamsters fed a high-fat/high-cholesterol diet. Samples were collected at different time points during the progression of hyperlipidemia, and individual proton NMR spectra were visually and statistically assessed using two multivariate analyses (MVA: principal component analysis (PCA and orthogonal partial least squares-discriminant analysis (OPLS-DA. Using the commercial software package Chenomx NMR suite, 40 endogenous metabolites in the plasma, 80 in the urine and 60 in the water-soluble fraction of liver extracts were quantified. NMR analysis of all samples showed a time-dependent transition from a physiological to a pathophysiological state during the progression of hyperlipidemia. Analysis of the identified biomarkers of hyperlipidemia suggests that significant perturbations of lipid and amino acid metabolism, as well as inflammation, oxidative stress and changes in gut microbiota metabolites, occurred following cholesterol overloading. The results of this study substantially broaden the metabonomic coverage of hyperlipidemia, enhance our understanding of the mechanism of hyperlipidemia and demonstrate the effectiveness of the NMR-based metabonomics approach to study a complex disease.

  3. Characterization of Maytenus ilicifolia samples by {sup 1}H NMR relaxation in the solid state; Caracterizacao dos constituintes polimericos da Maytenus ilicifolia por relaxacao nuclear de {sup 1}H por RMN no estado solido

    Preto, Monica S. de M.; Tavares, Maria I.B., E-mail: mibt@ima.ufrj.br [Universidade Federal do Rio de Janeiro (IMA/UFRJ), RJ (Brazil). Inst. de Macromoleculas Professora Eloisa Mano. Lab de Ressonancia Magnetica Nuclear; Sebastiao, Pedro J.O. [Departamento de Fisica, Instituto Superior Tecnico, Lisboa (Portugal)

    2011-07-01

    The Maytenus ilicifolia (espinheira-santa) is a popular medicinal plant with different uses. It is native of South America and can be found in Brazil. In the Brazilian market it is possible found products labeled as M. ilicifolia. So far, the studies published in the literature involve the modification of the natural materials and do not concern the comparison between commercial the raw natural materials. Different non-destructive NMR techniques can be used to study natural materials. In this work it is presented a characterization study by Fast Field Cycling of the {sup 1}H spin-lattice relaxation time (T{sub 1}) NMR, in the frequency range 100 khz-10 MHz. The results obtained in two commercial M. ilicifolia samples and one control sample collected in natura are compared. It was intended to study the possibility to elaborate a characterization method using FFCNMR suitable for the verification of authenticity and/or evaluation of tampering on products. The differences detected by FFCNMR relaxometry were confirmed by thermogravimetric analysis and infrared spectroscopy. (author)

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

    Applying the field-cycling nuclear magnetic resonance technique, the frequency dependence of the 1H spin-lattice relaxation rate, R1(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 R1(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

  5. Determination of nuclear distances and chemical-shift anisotropy from 1H MAS NMR sideband patterns of surface OH groups

    Fenzke, Dieter; Hunger, Michael; Pfeifer, Harry

    A procedure is described which allows a separate determination of the proton-aluminum distance and of the chemical-shift anisotropy for the bridging OH groups of crystalline molecular sieves from their 'H MAS NMR sideband patterns. For the bridging OH groups which point into the 6-rings of the framework (line "c"), the 1H- 27Al distance could be determined to be 0.237 ± 0.004 and 0.234 ± 0.004 nm for molecular sieves of type H-Y and SAPO-5, respectively. In contrast, for the bridging OH groups of the 12-rings (line "b"), the corresponding distances are equal and distinctly larger, 0.248 ± 0.004 nm. Within the limits of error, the values of the chemical-shift anisotropy are equal (about 19 ± 2 ppm) except for line b of SAPO-5, which exhibits a much smaller value of 14.5 ± 2 ppm.

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

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

    2012-10-15

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

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

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

    2016-06-29

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

  8. Quantification of radiation induced crosslinking in a commercial, toughened silicone rubber, TR-55, by 1H MQ-NMR

    Maxwell, R; Chinn, S; Alviso, C; Harvey, C A; Giuliani, J; Wilson, T; Cohenour, R

    2008-11-10

    Radiation induced degradation in a commercial, filled silicone composite has been studied by SPME/GC-MS, DMA, DSC, swelling, and Multiple Quantum NMR. Analysis of volatile and semivolatile species indicates degradation via decomposition of the peroxide curing catalyst and radiation induced backbiting reactions. DMA, swelling, and spin-echo NMR analysis indicate a increase in crosslink density of near 100% upon exposure to a cumulative dose of 250 kGray. Analysis of the sol-fraction via Charlseby-Pinner analysis indicates a ratio of chain scission to crosslinking yields of 0.38, consistent with the dominance of the crosslinking observed by DMA, swelling and spin-echo NMR and the chain scissioning reactions observed by MS analysis. Multiple Quantum NMR has revealed a bimodal distribution of residual dipolar couplings near 1 krad/sec and 5 krad/sec in an approximately 90:10 ratio, consistent with bulk network chains and chains associated with the filler surface. Upon exposure to radiation, the mean {Omega}{sub d} for both domains and the width of both domains both increased. The MQ NMR analysis provided increase insight into the effects of ionizing radiation on the network structure of silicone polymers.

  9. I. The synthesis and characterization of annulated uranocenes. II. The variable temperature 1H NMR of uranocenes

    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 UCl4. 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 1H NMR spectrum of uranocene has been reinvestigated from -100 to 1000C. The isotropic shift was found to be linear in T-1 with an extrapolated intercept of 0 at T-1 = 0. Variable temperature 1H NMR spectra, from -80 to 700C, 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

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

    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.

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

    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

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

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

  13. Structural polymorphism in new organic-inorganic hybrid: Pyrazolium bromoantimonates(III) [C 3N 2H 5] 6Sb 4Br 18·2H 2O (tetragonal and triclinic forms). Thermal, dielectric and proton magnetic resonance ( 1H NMR) studies on the tetragonal form

    Piecha, A.; Białońska, A.; Jakubas, R.; Medycki, W.

    2008-11-01

    Two polymorphic forms of pyrazolium bromoantimonates(III) - [C 3N 2H 5] 6Sb 4Br 18·2H 2O: α modification - tetragonal form and β modification - triclinic form, have been synthesized and structurally characterized at 100 K. The α-polymorph consists of a unique three-dimensional (3D) anionic substructure built up of cyclic tetramers and discrete chains linked to each other, three nonequivalent pyrazolium cations and water molecules. The β-polymorph is characterized by discrete cyclic anionic tetramers [Sb 4Br 18] -6, three nonequivalent cations and water molecules. The physical properties have been studied for the [C 3N 2H 5] 6Sb 4Br 18·2H 2O (α form). The differential scanning calorimetry (DSC) revealed a complex sequence of phase transitions above room temperature. The low-frequency dielectric relaxation process was found to appear at low temperatures, which was assigned to the dynamics of dipolar pyrazolium cations. The molecular motions of the pyrazolium cations in the α-polymorph were studied in a wide temperature range by means of a proton magnetic resonance ( 1H NMR) technique. Two minima of the spin-lattice relaxation time ( T1) are disclosed: at low temperatures a wide one attributed to a small-angle-libration of cations and motion of water molecules, whereas the high temperature one assigned to the reorientation of cation about its pseudo-fivefold axis.

  14. NMR (1H and 13C) based signatures of abnormal choline metabolism in oral squamous cell carcinoma with no prominent Warburg effect

    At functional levels, besides genes and proteins, changes in metabolome profiles are instructive for a biological system in health and disease including malignancy. It is understood that metabolomic alterations in association with proteomic and transcriptomic aberrations are very fundamental to unravel malignant micro-ambient criticality and oral cancer is no exception. Hence deciphering intricate dimensions of oral cancer metabolism may be contributory both for integrated appreciation of its pathogenesis and to identify any critical but yet unexplored dimension of this malignancy with high mortality rate. Although several methods do exist, NMR provides higher analytical precision in identification of cancer metabolomic signature. Present study explored abnormal signatures in choline metabolism in oral squamous cell carcinoma (OSCC) using 1H and 13C NMR analysis of serum. It has demonstrated down-regulation of choline with concomitant up-regulation of its break-down product in the form of trimethylamine N-oxide in OSCC compared to normal counterpart. Further, no significant change in lactate profile in OSCC possibly indicated that well-known Warburg effect was not a prominent phenomenon in such malignancy. Amongst other important metabolites, malonate has shown up-regulation but D-glucose, saturated fatty acids, acetate and threonine did not show any significant change. Analyzing these metabolomic findings present study proposed trimethyl amine N-oxide and malonate as important metabolic signature for oral cancer with no prominent Warburg effect. - Highlights: • NMR (1H and 13C) study of Oral Squamous cell Carcinoma Serum. • Abnormal Choline metabolomic signatures. • Up-regulation of Trimethylamine N-oxide. • Unchanged lactate profile indicates no prominent Warburg effect. • Proposed alternative glucose metabolism path through up-regulation of malonate

  15. NMR ({sup 1}H and {sup 13}C) based signatures of abnormal choline metabolism in oral squamous cell carcinoma with no prominent Warburg effect

    Bag, Swarnendu, E-mail: Swarna.bag@gmail.com [School of Medical Science and Technology, Indian Institute of Technology-Kharagpur, 721302 West Bengal (India); Banerjee, Deb Ranjan, E-mail: debranjan2@gmail.com [Department of Chemistry, Indian Institute of Technology-Kharagpur, 721302 West Bengal (India); Basak, Amit, E-mail: absk@chem.iitkgp.ernet.in [Department of Chemistry, Indian Institute of Technology-Kharagpur, 721302 West Bengal (India); Das, Amit Kumar, E-mail: amitk@hijli.iitkgp.ernet.in [Department of Biotechnology, Indian Institute of Technology-Kharagpur, 721302 West Bengal (India); Pal, Mousumi, E-mail: drmpal62@gmail.com [Department of Oral and Maxillofacial Pathology, Guru Nanak Institute of Dental Sciences and Research, Kolkata, West Bengal (India); Banerjee, Rita, E-mail: ritabanerjee@outlook.com [Department of Science and Technology, New Mehrauli Road, New Delhi 110016 (India); Paul, Ranjan Rashmi, E-mail: dr_rsspaul@yahoo.co.in [Department of Oral and Maxillofacial Pathology, Guru Nanak Institute of Dental Sciences and Research, Kolkata, West Bengal (India); Chatterjee, Jyotirmoy, E-mail: jchatterjee.iitkgp@gmail.com [School of Medical Science and Technology, Indian Institute of Technology-Kharagpur, 721302 West Bengal (India)

    2015-04-17

    At functional levels, besides genes and proteins, changes in metabolome profiles are instructive for a biological system in health and disease including malignancy. It is understood that metabolomic alterations in association with proteomic and transcriptomic aberrations are very fundamental to unravel malignant micro-ambient criticality and oral cancer is no exception. Hence deciphering intricate dimensions of oral cancer metabolism may be contributory both for integrated appreciation of its pathogenesis and to identify any critical but yet unexplored dimension of this malignancy with high mortality rate. Although several methods do exist, NMR provides higher analytical precision in identification of cancer metabolomic signature. Present study explored abnormal signatures in choline metabolism in oral squamous cell carcinoma (OSCC) using {sup 1}H and {sup 13}C NMR analysis of serum. It has demonstrated down-regulation of choline with concomitant up-regulation of its break-down product in the form of trimethylamine N-oxide in OSCC compared to normal counterpart. Further, no significant change in lactate profile in OSCC possibly indicated that well-known Warburg effect was not a prominent phenomenon in such malignancy. Amongst other important metabolites, malonate has shown up-regulation but D-glucose, saturated fatty acids, acetate and threonine did not show any significant change. Analyzing these metabolomic findings present study proposed trimethyl amine N-oxide and malonate as important metabolic signature for oral cancer with no prominent Warburg effect. - Highlights: • NMR ({sup 1}H and {sup 13}C) study of Oral Squamous cell Carcinoma Serum. • Abnormal Choline metabolomic signatures. • Up-regulation of Trimethylamine N-oxide. • Unchanged lactate profile indicates no prominent Warburg effect. • Proposed alternative glucose metabolism path through up-regulation of malonate.

  16. Chemical Origins of Permanent Set in a Peroxide Cured Filled Silicone Elastomer - Tensile and 1H NMR Analysis

    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.

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

    Gogna, Navdeep; Hamid, Neda; Dorai, Kavita

    2015-11-10

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

  18. 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.

    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

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

    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

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

    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

  1. A 1H nuclear magnetic resonance study of structural and organisational changes in the cell

    Increasing importance is being placed on understanding the role of membrane lipids in many different areas of biochemistry. It is of interest to determine what interactions may occur between membrane lipids and drug species. Furthermore, an increasing body of evidence suggests that membrane lipids are involved in the pathology of numerous diseases such as rheumatoid arthritis, cancer and HIV. Clearly, the more information available on the mechanisms involved in diseases, the greater the potential for identifying a cure or even a prevention. 1H nuclear magnetic resonance (NMR) spectroscopy was used to study the alterations in membrane lipid organisation and structure in intact, viable cultured cells. Changes in the 1H NMR spectra and the spin-lattice relaxation measurements of the human K562 and the rat FRTL-5 cell lines were observed on the addition of the fatty acid species: triolein, evening primrose oil, arachidonic acid and ITF 1779. Results indicate that the membrane lipids are reorganised to accommodate the interpolation of these molecules. The spatial arrangement adopted by each of these species appeared to dictate its effect on the lipids. Doxorubicin and menadione, both known to cause oxidative stress, were added to K562 cells. Although both agents are known to act by different mechanisms, the NMR data and scanning electron microscopy suggested that both caused similar alterations in the membrane organisation and lipid fluidity. Protrusions were formed indicating areas of weakness in the membrane. Spin-echo NMR was employed to investigate the action of the thiol-containing compounds, penicillamine, captopril and N-acetylcysteine in erythrocytes under conditions of oxidative stress. Results indicate that while captopril acts as a free radical scavenger, penicillamine may act as either oxidant or reductant. N-acetylcysteine was observed to act as a reducing agent. (author)

  2. (1H-NMR spectroscopy revealed Mycobacterium tuberculosis caused abnormal serum metabolic profile of cattle.

    Yingyu Chen

    Full Text Available To re-evaluate virulence of Mycobacterium tuberculosis (M. tb in cattle, we experimentally infected calves with M. tb andMycobacterium bovisvia intratracheal injection at a dose of 2.0×10(7 CFU and observed the animals for 33 weeks. The intradermal tuberculin test and IFN-γin vitro release assay showed that both M. tb and M. bovis induced similar responses. Immunohistochemical staining of pulmonary lymph nodes indicated that the antigen MPB83 of both M. tb and M. bovis were similarly distributed in the tissue samples. Histological examinations showed all of the infected groups exhibited neutrophil infiltration to similar extents. Although the infected cattle did not develop granulomatous inflammation, the metabolic profiles changed significantly, which were characterized by a change in energy production pathways and increased concentrations of N-acetyl glycoproteins. Glycolysis was induced in the infected cattle by decreased glucose and increased lactate content, and enhanced fatty acid β-oxidation was induced by decreased TG content, and decreased gluconeogenesis indicated by the decreased concentration of glucogenic and ketogenic amino acids promoted utilization of substances other than glucose as energy sources. In addition, an increase in acute phase reactive serum glycoproteins, together with neutrophil infiltration and increased of IL-1β production indicated an early inflammatory response before granuloma formation. In conclusion, this study indicated that both M. tb and M.bovis were virulent to cattle. Therefore, it is likely that cattle with M. tb infections would be critical to tuberculosis transmission from cattle to humans. Nuclear magnetic resonance was demonstrated to be an efficient method to systematically evaluate M. tb and M. bovi sinfection in cattle.

  3. Quantitative 1H NMR metabolite profiling as a functional genomics platform to investigate alkaloid biosynthesis in natural mutants of opium poppy

    Opium poppy (Papaver somniferum) produces a diverse array of bioactive benzylisoquinoline alkaloids and has emerged as a versatile model system to study plant alkaloid metabolism. The plant is widely cultivated as the only commercial source of the narcotic analgesics morphine and codeine. Variations in plant secondary metabolism as a result of genetic diversity are often associated with perturbations in other metabolic pathways. As part of a functional genomics platform, we have used 1H NMR metabolite profiling for the analysis of primary and secondary metabolism in opium poppy. Aqueous and chloroform extracts of six different opium poppy cultivars were subjected to chemometric analysis. Principle component analysis of the 1H NMR spectra for latex extracts clearly distinguished two natural mutants, including a low alkaloid variety, and a high-thebaine, low-morphine cultivar. Distinction was also made between pharmaceutical-grade opium poppy cultivars and a condiment variety. Such phenotypic differences were not observed in root extracts. Loadings plots confirmed that morphinan alkaloids contributed predominantly to the variance in latex extracts. Quantification of 34 root and 21 latex metabolites, performed using Chenomx NMR Suite v. 4.6, showed major differences in the accumulation of specific alkaloids in the latex of the low-alkaloid and high-thebaine, low-morphine mutants. However, few significant differences were found in the levels of other metabolites, indicating that the variation was highly specific for alkaloid metabolism. Exceptions included the accumulation of the alkaloid precursor tyramine in the low-alkaloid cultivar, in addition to altered levels of sucrose, select amino acids and malate. Real-time PCR analysis of 42 genes involved in primary and secondary metabolism showed differential gene expression mainly associated with alkaloid biosynthesis. Reduced alkaloid levels in the condiment variety were associated the reduced abundance of transcripts

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

    Schröder, Leif; Bachert, Peter

    2003-10-01

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

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

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

    2011-05-01

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

  6. Synthesis of new Co(III) hetero-ligand complexes with imidazole and 1-methylimidazole and their 1H, 13C and 59Co NMR spectra

    cis-[Co(en)2(1-MeIm)2]Cl3, fac-[do(dien)(ImH3]X3 (X = Cl-, NO3-, CLO4-) and fac[Co9dien)(1-MeIm)3]Cl3 complexes were prepared and characterized by absorption, 1H, NMR, 13C NMR and 59Co NMR spectra, where en, dien, ImH and 1-MeIm denote ethylenediamine, diethylenetriamine, imidazole and 1-methylimidazole, respectively. Calculated coordination-induced shifts (δcomplexed - δfree) ranged from =0.62 to -0.03 ppm for 1H and =7.11 to -1.19 ppm for 13C nuclei of imidazole ligands. The influence of imidazole methylation on 59Co NMR spectra was considered. (author)

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

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

    1989-01-01

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

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

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

    2016-05-01

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

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

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

    2009-01-01

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

  10. Other compounds isolated from Simira glaziovii and the {sup 1}H and {sup 13}C NMR chemical shift assignments of new 1-epi-castanopsol

    Araujo, Marcelo F. de; Vieira, Ivo J. Curcino [Universidade Federal Rural do Rio de Janeiro, Seropedica, RJ (Brazil). Dept. de Quimica; Braz-Filho, Raimundo [Universidade Estadual do Norte Fluminense (UENF), Campos dos Goytacases, RJ (Brazil). Centro de Ciencias Tecnologicas. Lab. de Ciencias Quimicas; Carvalho, Mario G. de, E-mail: mgeraldo@ufrrj.br [Universidade Federal do Rio de Janeiro (NPPN/UFRJ), RJ (Brazil). Centro de Ciencias da Saude. Nucleo de Pesquisa em Produtos Naturais

    2012-07-01

    A new triterpene, 1-epi-castanopsol, besides eleven known compounds: sitosterol, stigmasterol, campesterol, lupeol, lupenone, simirane B, syringaresinol, scopoletin, isofraxidin, 6,7,8-trimethoxycoumarin and harman, were isolated from the wood of Simira glaziovii. The structures of the known compounds were defined by 1D, 2D {sup 1}H, {sup 13}C NMR spectra data analyses and comparison with literature data. The detailed spectral data analyses allowed the definition of the structure of the new 1-epi isomer of castanopsol and performance of {sup 1}H and {sup 13}C NMR chemical shift assignments. (author)

  11. Other compounds isolated from Simira glaziovii and the 1H and 13C NMR chemical shift assignments of new 1-epi-castanopsol

    A new triterpene, 1-epi-castanopsol, besides eleven known compounds: sitosterol, stigmasterol, campesterol, lupeol, lupenone, simirane B, syringaresinol, scopoletin, isofraxidin, 6,7,8-trimethoxycoumarin and harman, were isolated from the wood of Simira glaziovii. The structures of the known compounds were defined by 1D, 2D 1H, 13C NMR spectra data analyses and comparison with literature data. The detailed spectral data analyses allowed the definition of the structure of the new 1-epi isomer of castanopsol and performance of 1H and 13C NMR chemical shift assignments. (author)

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

    Saji Thomas

    2014-10-01

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

  13. The relationship between reorientational molecular motions and phase transitions in [Mg(H{sub 2}O){sub 6}](BF{sub 4}){sub 2}, studied with the use of {sup 1}H and {sup 19}F NMR and FT-MIR

    Mikuli, Edward, E-mail: mikuli@chemia.uj.edu.pl; Hetmańczyk, Joanna [Faculty of Chemistry, Jagiellonian University, Ingardena 3, 30-060 Kraków (Poland); Grad, Bartłomiej [Department of Forest Pathology, Faculty of Forestry, Agricultural University of Cracow, Aleja 29 listopada 46, 31-425 Kraków (Poland); Kozak, Asja; Wąsicki, Jan W.; Bilski, Paweł; Hołderna-Natkaniec, Krystyna [Faculty of Physics, A. Mickiewicz University, Umultowska 85, 61-614 Poznań (Poland); Medycki, Wojciech [Institute of Molecular Physics, Polish Academy of Sciences, Smoluchowskiego 17, 60-179 Poznań (Poland)

    2015-02-14

    A {sup 1}H and {sup 19}F nuclear magnetic resonance study of [Mg(H{sub 2}O){sub 6}](BF{sub 4}){sub 2} has confirmed the existence of two phase transitions at T{sub c1} ≈ 257 K and T{sub c2} ≈ 142 K, detected earlier by the DSC method. These transitions were reflected by changes in the temperature dependences of both proton and fluorine of second moments M{sub 2}{sup H} and M{sub 2}{sup F} and of spin-lattice relaxation times T{sub 1}{sup H} and T{sub 1}{sup F}. The study revealed anisotropic reorientations of whole [Mg(H{sub 2}O){sub 6}]{sup 2+} cations, reorientations by 180° jumps of H{sub 2}O ligands, and aniso- and isotropic reorientations of BF{sub 4}{sup −} anions. The activation parameters for these motions were obtained. It was found that the phase transition at T{sub c1} is associated with the reorientation of the cation as a whole unit around the C{sub 3} axis and that at T{sub c2} with isotropic reorientation of the BF{sub 4}{sup −} anions. The temperature dependence of the full width at half maximum value of the infrared band of ρ{sub t}(H{sub 2}O) mode (at ∼596 cm{sup −1}) indicated that in phases I and II, all H{sub 2}O ligands in [Mg(H{sub 2}O){sub 6}]{sup 2+} perform fast reorientational motions (180° jumps) with a mean value of activation energy equal to ca 10 kJ mole{sup −1}, what is fully consistent with NMR results. The phase transition at T{sub c1} is associated with a sudden change of speed of fast (τ{sub R} ≈ 10{sup −12} s) reorientational motions of H{sub 2}O ligands. Below T{sub c2} (in phase III), the reorientations of certain part of the H{sub 2}O ligands significantly slow down, while others continue their fast reorientation with an activation energy of ca 2 kJ mole{sup −1}. This fast reorientation cannot be evidenced in NMR relaxation experiments. Splitting of certain IR bands connected with H{sub 2}O ligands at the observed phase transitions suggests a reduction of the symmetry of the octahedral [Mg(H{sub 2}O

  14. 1H HR-MAS NMR Spectroscopy and the Metabolite Determination of Typical Foods in Mediterranean Diet

    Carmelo Corsaro

    2015-01-01

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

  15. Dynamics of ethylene-propylene random copolymers by (1)H and (13)C solid-state NMR.

    Mollica, G; Forte, C; Malvaldi, M; Geppi, M

    2011-03-10

    The dynamic behavior of three completely amorphous ethylene-propylene random copolymers with slightly different structural properties was investigated by means of a multifrequency global fitting approach, presented in a previous paper. To this end, the trends of NMR (1)H and (13)C spin-lattice relaxation times with temperature, obtained at different frequencies, were analyzed by means of unified motional models for the segmental main-chain motion and rotation of methyl groups about their ternary symmetry axis. To evaluate the reliability of both the models and the method used with respect to the dimensionality of the data set, as well as to identify the minimal data set to be used for getting reliable dynamic information on similar systems, the fitting results obtained from the analysis of three different experimental data sets collected on the same polymer were compared. The data collected on the three polymers using the minimal data set were analyzed and the results discussed to evaluate the degree of sensitivity of the method to differences in the dynamic behavior of structurally similar systems. The results demonstrated that the method shows good sensitivity to the use of different dynamic models depending on the number and/or type of relaxation curves included in the analysis and that variations in the dynamic features of the same motions on different systems can be revealed even in the presence of polymeric systems characterized by very similar structural properties. PMID:21319756

  16. 1H NMR identification of a β-sheet structure and description of folding topology in putidaredoxin

    Putidaredoxin (Pdx), a 106-residue globular protein consisting of a single polypeptide chain and a [2Fe-2S] cluster, is the physiological reductant of P-450cam, 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 1H NMR methods to the problem of structure determination in Pdx is reported. A β-sheet consisting of five short strands and one β-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 β-sheet have been assigned sequence specifically. The sheet contains one parallel and three antiparallel strand orientations. Hydrophobic side chains in the β-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 β-sheet, is compared with that of other [2Fe-2S] proteins for which folding topologies are known

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

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

  18. 1H and 13C NMR Chemical Shift Assignments and Conformational Analysis for the Two Diastereomers of the Vitamin K Epoxide Reductase Inhibitor Brodifacoum

    Proton and 13C NMR chemical shift assignments and 1H-1H scalar couplings for the two diastereomers of the vitamin K epoxide reductase (VKOR) inhibitor brodifacoum have been determined from acetone solutions containing both diastereomers. Data were obtained from homo- and heteronuclear correlation spectra acquired at 1H frequencies of 750 and 900 MHz over a 268-303 K temperature range. Conformations inferred from scalar coupling and 1-D NOE measurements exhibit large differences between the diastereomers. Pacific Northwest National Laboratory is operated by Battelle for the US Department of Energy.

  19. 1H, 13C and 13N chemical shifts and 1H-15N and 13C-15N heteronuclear spin-spin coupling constants n the NMR spectra of 5-substituted furfural oximes

    The 1H, 13C, and 15N NMR spectra of 15N-enriched 5-substituted furfural oximes were investigated. It was shown that the chemical shifts of the ring atoms and the oxime group correlate satisfactorily with the F and R substituent constants, whereas their sensitivity to the effect of the substituents is lower than in monosubstituted furan derivatives. The constants of spin-spin coupling between the ring protons and the oxime group were determined. An analysis of the 1H-1H spin-spin coupling constants (SSCC) on the basis of their stereospecificity indicates that the E isomers have primarily an s-trans conformation in polar dimethyl sulfoxide, whereas the Z isomers, on the other hand, have an s-cis conformation. The signs of the direct and geminal 13C-15N SSCC were determined for 5-trimethylsilylfurfural oxime

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

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

    2004-01-01

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

  1. Establishing 1H nuclear magnetic resonance based metabonomics fingerprinting profile for spinal cord injury: a pilot study

    JIANG Hua; PENG Jin; ZHOU Zhi-yuan; DUAN Yu; CHEN Wei; CAI Bin; YANG Hao; ZHANG Wei

    2010-01-01

    Background Spinal cord injury (SCI) is a complex trauma that consists of multiple pathological mechanisms involving cytotoxic, oxidation stress and immune-endocrine. This study aimed to establish plasma metabonomics fingerprinting atlas for SCI using 1H nuclear magnetic resonance (NMR) based metabonomics methodology and principal component analysis techniques.Methods Nine Sprague-Dawley (SD) male rats were randomly divided into SCI, normal and sham-operation control groups. Plasma samples were collected for 1H NMR spectroscopy 3 days after operation. The NMR data were analyzed using principal component analysis technique with Matlab software.Results Metabonomics analysis was able to distinguish the three groups (SCI, normal control, sham-operation). The fingerprinting atlas indicated that, compared with those without SCI, the SCI group demonstrated the following characteristics with regard to second principal component: it is made up of fatty acids, myc-inositol, arginine, very low-density lipoprotein (VLDL), low-density lipoprotein (LDL), triglyceride (TG), glucose, and 3-methyl-histamine.Conclusions The data indicated that SCI results in several significant changes in plasma metabolism early on and that a metabonomics approach based on 1H NMR spectroscopy can provide a metabolic profile comprising several metabolite classes and allow for relative quantification of such changes. The results also provided support for further development and application of metabonomics technologies for studying SCI and for the utilization of multivariate models for classifying the extent of trauma within an individual.

  2. 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.

    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

  3. (1)H NMR-based metabolomics investigation of Daphnia magna responses to sub-lethal exposure to arsenic, copper and lithium.

    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. Tracing bacterial metabolism using multi-nuclear (1H, 2H, and 13C) Solid State NMR: Realizing an Idea Initiated by James Scott

    Cody, G.; Fogel, M. L.; Jin, K.; Griffen, P.; Steele, A.; Wang, Y.

    2011-12-01

    Approximately 6 years ago, while at the Geophysical Laboratory, James Scott became interested in the application of Solid State Nuclear Magnetic Resonance Spectroscopy to study bacterial metabolism. As often happens, other experiments intervened and the NMR experiments were not pursued. We have revisited Jame's question and find that using a multi-nuclear approach (1H, 2H, and 13C Solid State NMR) on laboratory cell culture has some distinct advantages. Our experiments involved batch cultures of E. coli (MG1655) harvested at stationary phase. In all experiments the growth medium consisted of MOPS medium for enterobacteria, where the substrate is glucose. In one set of experiments, 10 % of the water was D2O; in another 10 % of the glucose was per-deuterated. The control experiment used both water and glucose at natural isotopic abundance. A kill control of dead E. coli immersed in pure D2O for an extended period exhibited no deuterium incorporation. In both deuterium enriched experiments, considerable incorporation of deuterium into E. coli's biomolecular constituents was detected via 2H Solid State NMR. In the case of the D2O enriched experiment, 58 % of the incorporated deuterium is observed in a sharp peak at a frequency of 0.31 ppm, consistent with D incorporation in the cell membrane lipids, the remainder is observed in a broad peak at a higher frequency (centered at 5.4 ppm, but spanning out to beyond 10 ppm) that is consistent with D incorporation into predominantly DNA and RNA. In the case of the D-glucose experiments, 61 % of the deuterium is observed in a sharp resonance peak at 0.34 ppm, also consistent with D incorporation into membrane lipids, the remainder of the D is observed at a broad resonance peak centered at 4.3 ppm, consistent with D enrichment in glycogen. Deuterium abundance in the E. coli cells grown in 10 % D2O is nearly 2X greater than that grown with 10 % D-glucose. Very subtle differences are observed in both the 1H and 13C solid

  5. Investigation of 1H NMR Profile of Vegetarian Human Urine Using ANOVA-based Multi-factor Analysis%素食人群尿液1H NMR代谢轮廓的多因素方差分析

    董继扬; 邓伶莉; CHENG Kian-Kai; GRIFFIN Julian L.; 陈忠

    2011-01-01

    结合方差分析(ANOVA)和偏最小二乘法判别分析(PLS-DA)两种分析技术,对素食和普食人群的尿液1H NMR谱进行分析.利用ANOVA方法将数据矩阵分解为几个独立因素矩阵,滤除干扰因素后,再利用PLS-DA对单因素数据进行建模分析.实验结果表明,ANOVA/PLS-DA方法可以有效地减少饮食因素和性别因素之间的相互影响,使分析结果更具有生物学意义.%In this study, a technique that combined both analysis of variance ( ANOVA) and partial least squares-discriminant analysis (PLS-DA) was used to compare the urine XH NMR spectra of healthy people from a vegetarian and omnivorous population. In ANOVA/PLS-DA, the variation in data was first decomposed into different variance components that each contains a single source of variation. Each of the resulting variance components was then analyzed using PLS-DA. The experimental results showed that ANOVA/PLS-DA is efficient in disentangling the effect of diet and gender on die metabolic profile, and the method could be used to extract biologically relevant information for result interpretation.

  6. NMR Studies on the Subacute Biochemical Effects of Aristolochic Acid on Rat Serum

    Xiao Yu ZHANG; Hui Feng WU; Xiao Jing LI; Feng Kui PEI; Jia Zuan NI

    2005-01-01

    The subacute effect of aristolochic acid (AA) on rat serum was studied by NMR method.The biochemical effects induced by AA were characterized by an increase in the amounts of creatinine, trimethylamine N-oxide, acetoacetate, acetate and 3-D-hydroxybutyrate and lactate in serum from 1H NMR spectra. Principal component analysis was used for further comparing the similarities of 1H NMR spectral profiles of serum from rats treated with AA and model toxins.

  7. 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.

    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

  8. NMR methodologies for studying mitochondrial bioenergetics.

    Alves, Tiago C; Jarak, Ivana; Carvalho, Rui A

    2012-01-01

    Nuclear magnetic resonance (NMR) spectroscopy is a technique with an increasing importance in the study of metabolic diseases. Its initial important role in the determination of chemical structures (1, 2) has been considerably overcome by its potential for the in vivo study of metabolism (3-5). The main characteristic that makes this technique so attractive is its noninvasiveness. Only nuclei capable of transitioning between energy states, in the presence of an intense and constant magnetic field, are studied. This includes abundant nuclei such as proton ((1)H) and phosphorous ((31)P), as well as stable isotopes such as deuterium ((2)H) and carbon 13 ((13)C). This allows a wide range of applications that vary from the determination of water distribution in tissues (as obtained in a magnetic resonance imaging scan) to the calculation of metabolic fluxes under ex vivo and in vivo conditions without the need to use radioactive tracers or tissue biopsies (as in a magnetic resonance spectroscopy (MRS) scan). In this chapter, some technical aspects of the methodology of an NMR/MRS experiment as well as how it can be used to study mitochondrial bioenergetics are overviewed. Advantages and disadvantages of in vivo MRS versus high-resolution NMR using proton high rotation magic angle spinning (HRMAS) of tissue biopsies and tissue extracts are also discussed. PMID:22057574

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

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

    2014-11-15

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

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

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

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

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

    2016-06-01

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

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

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

    2001-10-01

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

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

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

    2001-10-01

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

  14. 核磁共振技术结合模式识别对中药马兜铃酸亚急性生化效应的研究%Studies on Subacute Biochemical Effects of Aristolochic Acid Using 1H NMR Spectroscopy Combined with Pattern Recognition

    张晓宇; 吴惠丰; 裴奉奎; 倪嘉缵

    2005-01-01

    利用核磁共振技术结合模式识别方法, 研究了马兜铃酸(Aristolochic Acid, AA)的亚急性生化效应. 大鼠连续5日腹腔注射马兜铃酸后, 不同时间段尿液 1H NMR谱显示与肾小管及肾乳头受损相关的标记物(NMR marker)浓度有显著变化; 铬酸钠、氯化汞、二溴乙胺、盐酸肼和异硫氰酸-α-萘酯, 并利用主成分分析法对造成的肝肾损伤模型组、 AA组和对照组的大鼠尿液 1H NMR谱解析和分类. 1H NMR谱中各种代谢物的谱峰强度变化及主成分分析结果均显示, 马兜铃酸引起的肾损伤与肾小管及肾乳头损伤模型类似, 且随给药量的积累, 肾损伤范围扩大程度加深, 引起肾脏不可逆损伤. 该方法可用于中药的毒理学研究.

  15. Preparation, GIAO NMR Calculations and Acidic Properties of Some Novel 4,5-dihydro-1H-1,2,4-triazol-5-one Derivatives with Their Antioxidant Activities

    Havva Aksu

    2008-01-01

    Full Text Available Six novel 3-alkyl(aryl-4-(p-nitrobenzoylamino-4,5-dihydro-1H-1,2,4-triazol-5- ones (2a-f were synthesized by the reactions of 3-alkyl(aryl-4-amino-4,5-dihydro-1H- 1,2,4-triazol-5-ones (1a-f with p-nitrobenzoyl chloride and characterized by elemental analyses and IR, 1H-NMR, 13C-NMR and UV spectral data. The newly synthesized compounds 2 were titrated potentiometrically with tetrabutylammonium hydroxide in four non-aqueous solvents such as acetone, isopropyl alcohol, tert-butyl alcohol and N,Ndimethylformamide, and the half-neutralization potential values and the corresponding pKa values were determined for all cases. Thus, the effects of solvents and molecular structure upon acidity were investigated. In addition, isotropic 1H and 13C nuclear magnetic shielding constants of compounds 2 were obtained by the gauge-including-atomic-orbital (GIAO method at the B3LYP density functional level. The geometry of each compound has been optimized using the 6-311G basis set. Theoretical values were compared to the experimental data. Furthermore, these new compounds and five recently reported 3-alkyl-4-(2- furoylamino-4,5-dihydro-1H-1,2,4-triazol-5-ones (3a-c,e,f were screened for their antioxidant activities.

  16. Rhodopsin-lipid interactions studied by NMR.

    Soubias, Olivier; Gawrisch, Klaus

    2013-01-01

    The biophysical properties of the lipid matrix are known to influence function of integral membrane proteins. We report on a sample preparation method for reconstitution of membrane proteins which uses porous anodic aluminum oxide (AAO) filters with 200-nm-wide pores of high density. The substrate permits formation of tubular, single membranes that line the inner surface of pores. One square centimeter of filter with a thickness of 60μm yields on the order of 500cm(2) of solid-supported single bilayer surface, sufficient for NMR studies. The tubular bilayers are free of detergent, fully hydrated, and accessible for ligands from one side of the membrane. The use of AAO filters greatly improves reproducibility of the reconstitution process such that the influence of protein on lipid order parameters can be studied with high resolution. As an example, results for the G protein-coupled receptor of class A, bovine rhodopsin, are shown. By (2)H NMR order parameter measurements, it is detected that rhodopsin insertion elastically deforms membranes near the protein. Furthermore, by (1)H saturation-transfer NMR under conditions of magic angle spinning, we demonstrate detection of preferences in interactions of rhodopsin with particular lipid species. It is assumed that function of integral membrane proteins depends on both protein-induced elastic deformations of the lipid matrix and preferences for interaction of the protein with particular lipid species in the first layer of lipids surrounding the protein. PMID:23374188

  17. Conformational distribution of baclofen analogues by 1H and 13C NMR analysis and ab initio HF MO STO-3G or STO-3G* calculations

    Vaccher, Claude; Berthelot, Pascal; Debaert, Michel; Vermeersch, Gaston; Guyon, René; Pirard, Bernard; Vercauteren, Daniel P.; Dory, Magdalena; Evrard, Guy; Durant, François

    1993-12-01

    The conformations of 3-(substituted furan-2-yl) and 3-(substituted thien-2-yl)-γ-aminobutyric acid 1-9 in solution (D 2O) are estimated from high-resolution (300 MHz) 1H NMR coupling data. Conformations and populations of conformers are calculated by means of a modified Karplus-like relationship for the vicinal coupling constants. The results are compared with X-ray crystallographic investigations (torsion angles) and ab initio HF MO ST-3G or STO-3G* calculations. 1H NMR spectral analysis shows how 1-9 in solution retain the preferred g- conformation around the C3C4 bond, as found in the solid state, while a partial rotation is set up around the C2C3 bond: the conformations about C2C3 are all highly populated in solution. The 13C spin-lattice relaxation times are also discussed.

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

    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

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

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

    2014-11-01

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

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

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

    2014-01-01

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

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

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

  2. 1H NMR-Based Metabolomic Analysis of Sub-Lethal Perfluorooctane Sulfonate Exposure to the Earthworm, Eisenia fetida, in Soil

    Myrna J. Simpson

    2013-08-01

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

  3. 1H NMR-Based Metabolomic Analysis of Sub-Lethal Perfluorooctane Sulfonate Exposure to the Earthworm, Eisenia fetida, in Soil.

    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

  4. Extraction of multiple pure component 1H and 13C NMR spectra from two mixtures: Novel solution obtained by sparse component analysis-based blind decomposition

    Sparse component analysis (SCA) is demonstrated for blind extraction of three pure component spectra from only two measured mixed spectra in 13C and 1H nuclear magnetic resonance (NMR) spectroscopy. This appears to be the first time to report such results and that is the first novelty of the paper. Presented concept is general and directly applicable to experimental scenarios that possibly would require use of more than two mixtures. However, it is important to emphasize that number of required mixtures is always less than number of components present in these mixtures. The second novelty is formulation of blind NMR spectra decomposition exploiting sparseness of the pure components in the wavelet basis defined by either Morlet or Mexican hat wavelet. This enabled accurate estimation of the concentration matrix and number of pure components by means of data clustering algorithm and pure components spectra by means of linear programming with constraints from both 1H and 13C NMR experimental data. The third novelty is capability of proposed method to estimate number of pure components in demanding underdetermined blind source separation (uBSS) scenario. This is in contrast to majority of the BSS algorithms that assume this information to be known in advance. Presented results are important for the NMR spectroscopy-associated data analysis in pharmaceutical industry, medicine diagnostics and natural products research.

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

    Henrichsen, Magnus Rossmann

    2015-01-01

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

  6. NMR Dynamic Studies in Living Systems

    闫永彬; 范明杰; 罗雪春; 张日清

    2002-01-01

    Nuclear magnetic resonance (NMR) can noninvasively monitor the intracellular concentrations and kinetic properties of numerous inorganic and organic compounds. These characteristics have made NMR a useful tool for dynamic studies of living systems. Applications of NMR to living systems have successfully extended to many areas, including studies of metabolic regulation, ion transport, and intracellular reaction rates in vivo. The major purpose of this review is to summarize the results that can be obtained by modern NMR techniques in living systems. With the advances of new techniques, NMR measurements of various nuclides have been performed for specific physiological purposes. Although some technical problems still remain and there are still discrepancies between NMR and traditional biochemical results, the abundant and unique information obtained from NMR spectra suggests that NMR will be more extensively applied in future studies of living systems. The fast development of these new techniques is providing many new NMR applications in living systems, as well as in structural biology.

  7. Multivariate analysis of fingerprinting of majority secondary metabolites of propolis of Costa Rica using proton nuclear magnetic resonance (1H-NMR)

    Propolis is produced by Apis mellifera bees from resins of plants that are found around the apiary. The chemical composition is highly variable and Costa Rica has reported without studies of characterization to define the types of propolis in the country. 119 samples were collected from beekeeping areas of the country. The spectrum of 1H-NMR and its antioxidant activity against DPPH radical were measured. The spectra have been divided into 243 blocks of 0,04 ppm and processed with the Minitab software for multivariate analysis. 99 of the samples collected were used for construction of models for the valuation of the predictive ability of the model have been used coefficients of determination (R2) of prediction by the software and the remaining 20 samples. The existence of three types of propolis with chemically different metabolomes were determined by principal component analysis (PCA). A prediction model was constructed by analysis of partial least squares (PLS). The prediction model has allowed to classify a propolis according to the level of anti-oxidant activity (AAO), high (type I and II) or low (type III) from the spectrum of 1H-NMR. The R2 has been 0.88 and R2 prediction of 0, 718 for new samples. The n-coniferyl benzoate of group I and nemorosone of the group II as two discriminated antioxidants among the groups I and II were isolated and high concentration levels of these compounds have been differentiated with respect to type III. This has allowed the construction of a linear discriminant model with a success rate of 100% for the samples used for formulation and 92,9 for the prediction of different samples. The classification systems could be applied to the standardization of the quality of propolis from Costa Rica for future medicinal or cosmetic applications that take advantage of its antioxidant properties. Also, the methylated derivative has isolated and identified of the n-coniferyl benzoate thereof propolis than was obtained his counterpart

  8. Characterization of pH-dependent conformational heterogeneity in Rhodospirillum rubrum cytochrome c2 using 15N and 1H NMR

    The 15N-enriched ferricytochrome c2 from Rhodospirillum rubrum has been studied by 15N and 1H NMR spectroscopy as a function of pH. The 15N resonance of the heme and ligand τ nitrogen are broadened beyond detection because of paramagnetic relaxation. The 15N resonance of the ligand histidine π nitrogen was unambiguously identified at 184 ppm (pH 5.6). The 15N resonances of the single nonligand histidine are observed only at low pH, as in the ferrocytochrome because of the severe broadening caused by tautomerization. The dependence of the 15N and 1H spectra of the ferricytochrome on pH indicated that the ligand histidine π NH does not dissociate in the neutral pH range and is involved in a hydrogen bond, similar to that in the reduced state. Transitions having pKa's of 6.2, 8.6, and 9.2 are observed in the ferricytochrome. Structural heterogeneity leads to multiple resonances of the heme ring methyl at position 8. The exchange rate between the conformations is temperature dependent. The transition with a pKa of 6.2 is assigned to the His-42 imidazole group. The displacement of the ligand methionine causes gross conformational change near the heme center. There are multiple conformations at high pH, as judged by saturation-transfer experiments. The N-terminus of the ferricytochrome has a pKa of 8.6. In contrast to its partially restricted mobility in the reduced state, it is found to be very mobile, reflecting a looser structure of the ferricytochrome

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

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

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

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

    2008-07-14

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

  11. 1H NMR-based metabolomics investigation of copper-laden rat: a model of Wilson's disease.

    Jingjing Xu

    Full Text Available Wilson's disease (WD, also known as hepatoleticular degeneration (HLD, is a rare autosomal recessive genetic disorder of copper metabolism, which causes copper to accumulate in body tissues. In this study, rats fed with copper-laden diet are used to render the clinical manifestations of WD, and their copper toxicity-induced organ lesions are studied. To investigate metabolic behaviors of 'decoppering' process, penicillamine (PA was used for treating copper-laden rats as this chelating agent could eliminate excess copper through the urine. To date, there has been limited metabolomics study on WD, while metabolic impacts of copper accumulation and PA administration have yet to be established.A combination of 1HNMR spectroscopy and multivariate statistical analysis was applied to examine the metabolic profiles of the urine and blood serum samples collected from the copper-laden rat model of WD with PA treatment.Copper accumulation in the copper-laden rats is associated with increased lactate, creatinine, valine and leucine, as well as decreased levels of glucose and taurine in the blood serum. There were also significant changes in p-hydroxyphenylacetate (p-HPA, creatinine, alpha-ketoglutarate (α-KG, dimethylamine, N-acetylglutamate (NAG, N-acetylglycoprotein (NAC in the urine of these rats. Notably, the changes in p-HPA, glucose, lactate, taurine, valine, leucine, and NAG were found reversed following PA treatment. Nevertheless, there were no changes for dimethylamine, α-KG, and NAC as a result of the treatment. Compared with the controls, the concentrations of hippurate, formate, alanine, and lactate were changed when PA was applied and this is probably due to its side effect. A tool named SMPDB (Small Molecule Pathway Database is introduced to identify the metabolic pathway influenced by the copper-laden diet.The study has shown the potential application of NMR-based metabolomic analysis in providing further insights into the molecular

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

    Fuqiu Wang

    2015-01-01

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

  13. (1) H-NMR screening for the high-throughput determination of genotype and environmental effects on the content of asparagine in wheat grain.

    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

  14. NMR Studies of Inclusion Compounds

    Nikkhou Aski, Sahar

    2008-01-01

    This thesis presents the application of some of the NMR methods in studying host-guest complexes, mainly in solution. The general focus of the work is on investigating the reorientational dynamics of some small molecules that are bound inside cavities of larger moieties. In the current work, these moieties belong to two groups: cryptophanes and cyclodextrins. Depending on the structure of the cavities, properties of the guest molecules and the formed complexes vary. Chloroform and dichloromet...

  15. Effects of glycosaminoglycan in the nucleus pulposus of cow on the /sup 1/H-NMR relaxation times and dynamic viscoelasticity

    Ohtomo, Satoshi

    1988-11-01

    Nucleus pulposus of the intervertebral disc (NP) has viscoelasticity owing to its high water content. The purpose of this study is to clarify the effects of glycosaminoglycan (GAG) on the mechanical property of NP by examining its interaction with water molecules. Nucleus pulposus of cow discs containing two different amounts of GAG were prepared: non-treated NP and GAG-depleted NP by treatment of hyaluronidase. The /sup 1/H-NMR relaxation times (T/sub 1/, T/sub 2/) indicating the mobility of water, and dynamic viscoelasticity (chemically bondE*chemically bond) of those materials were measured. The results suggested that the chemically bondE*chemically bond value in the normal NP depended on the mobility of water, which is regulated mainly by its interaction with GAG. On the other hand, the chemically bondE*chemically bond value in the GAG-depleted NP depended not only on the mobility of water but also on the elasticity of the collagen fiber in the NP. In conclusion, GAG plays an important role in the viscoelastic property of the NP by retaining water and by restricting its mobility.

  16. Application of {sup 1}H-NMR-based metabolomics for detecting injury induced by long-term microwave exposure in Wistar rats' urine

    Wang, Li-Feng; Peng, Rui-Yun; Wang, Shui-Ming; Gao, Ya-Bing; Dong, Ji; Zhao, Li; Li, Xiang; Zuo, Hong-Yan; Wang, Chang-Zhen [Beijing Institute of Radiation Medicine, Laboratory of Pathology, Beijing (China); Hu, Xiang-Jun [Beijing Institute of Radiation Medicine, Beijing (China); Gao, Rong-Lian [Beijing Institute of Radiation Medicine, Laser Medicine, Beijing (China); Su, Zhen-Tao [Beijing Institute of Radiation Medicine, Radiation Protection, Beijing (China); Feng, Xin-Xing [Chinese Academy of Medical Sciences, Endocrine and Cardiovascular Center, Fuwai Hospital and Cardiovascular Institute, Beijing (China)

    2012-07-15

    There has been growing public concern regarding exposure to microwave fields as a potential human health hazard. This study aimed to identify sensitive biochemical indexes for the detection of injury induced by microwave exposure. Male Wistar rats were exposed to microwaves for 6 min per day, 5 days per week over a period of 1 month at an average power density of 5 mW/cm{sup 2} (specific absorption rate of 2.1 W/kg). Urine specimens were collected over 24 h in metabolic cages at 7 days, 21 days, 2 months, and 6 months after exposure. {sup 1}H NMR spectroscopy data were analyzed using multivariate statistical techniques. Urine metabolic profiles of rats after long-term microwave exposure were significantly differentiated from those of sham-treated controls using principal component analysis or partial least squares discriminant analysis. Significant differences in low molecular weight metabolites (acetate, succinate, citrate, ketoglutarate, glucose, taurine, phenylalanine, tyrosine, and hippurate) were identified in the 5 mW/cm{sup 2} microwave exposure group compared with the sham-treated controls at 7 days, 21 days, and 2 months. Metabolites returned to normal levels by 6 months after exposure. These data indicated that these metabolites were related to the perturbations of energy metabolism particularly in the tricarboxylic acid cycle, and the metabolism of amino acids, monoamines, and choline in urine represent potential indexes for the detection of injury induced by long-term microwave exposure. (orig.)

  17. 1H NMR metabonomics indicates continued metabolic changes and sexual dimorphism post-parasite clearance in self-limiting murine malaria model.

    Arjun Sengupta

    Full Text Available Malaria, a mosquito-borne disease caused by Plasmodium spp. is considered to be a global threat, specifically for the developing countries. In human subjects considerable information exists regarding post-malarial physiology. However, most murine malarial models are lethal, and most studies deal with acute phases occurring as disease progresses. Much less is known regarding physiological status post-parasite clearance. We have assessed the physiological changes at the organ levels using (1H NMR based metabonomics in a non lethal self-clearing murine malarial model of P. chabaudi parasites and Balb/C, far beyond the parasite clearance point. The results showed distinct metabolic states between uninfected and infected mice at the peak parasitemia, as well as three weeks post-parasite clearance. Our data also suggests that the response at the peak infection as well as recovery exhibited distinct sexual dimorphism. Specifically, we observed accumulation of acetylcholine in the brain metabolic profile of both the sexes. This might have important implication in understanding the pathophysiology of the post malarial neurological syndromes. In addition, the female liver showed high levels of glucose, dimethylglycine, methylacetoacetate and histidine after three weeks post-parasite clearance, while the males showed accumulation of branched chain amino acids, lysine, glutamine and bile acids.

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

    Zhang, Sheng; Echegoyen, Luis

    2005-02-16

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

  19. Comprehensive quantum chemical and spectroscopic (FTIR, FT-Raman, 1H, 13C NMR) investigations of O-desmethyltramadol hydrochloride an active metabolite in tramadol - An analgesic drug

    Arjunan, V.; Santhanam, R.; Marchewka, M. K.; Mohan, S.

    2014-03-01

    O-desmethyltramadol is one of the main metabolites of tramadol widely used clinically and has analgesic activity. The FTIR and FT-Raman spectra of O-desmethyl tramadol hydrochloride are recorded in the solid phase in the regions 4000-400 cm-1 and 4000-100 cm-1, respectively. The observed fundamentals are assigned to different normal modes of vibration. Theoretical studies have been performed as its hydrochloride salt. The structure of the compound has been optimised with B3LYP method using 6-31G** and cc-pVDZ basis sets. The optimised bond length and bond angles are correlated with the X-ray data. The experimental wavenumbers were compared with the scaled vibrational frequencies determined by DFT methods. The IR and Raman intensities are determined with B3LYP method using cc-pVDZ and 6-31G(d,p) basic sets. The total electron density and molecular electrostatic potential surfaces of the molecule are constructed by using B3LYP/cc-pVDZ method to display electrostatic potential (electron + nuclei) distribution. The electronic properties HOMO and LUMO energies were measured. Natural bond orbital analysis of O-desmethyltramadol hydrochloride has been performed to indicate the presence of intramolecular charge transfer. The 1H and 13C NMR chemical shifts of the molecule have been anlysed.

  20. 1H-MAS-NMR Chemical Shifts in Hydrogen-Bonded Complexes of Chlorophenols (Pentachlorophenol, 2,4,6-Trichlorophenol, 2,6-Dichlorophenol, 3,5-Dichlorophenol, and p-Chlorophenol) and Amine, and H/D Isotope Effects on 1H-MAS-NMR Spectra

    Hisashi Honda

    2013-01-01

    Chemical shifts (CS) of the 1H nucleus in N···H···O type hydrogen bonds (H-bond) were observed in some complexes between chlorophenols [pentachlorophenol (PCP), 2,4,6-tricholorophenol (TCP), 2,6-dichlorophenol (26DCP), 3,5-dichlorophenol (35DCP), and p-chlorophenol (pCP)] and nitrogen-base (N-Base) by solid-state high-resolution 1H-NMR with the magic-angle-spinning (MAS) method. Employing N-Bases with a wide range of pKa values (0.65–10.75), 1H-MAS-NMR CS values of bridging H atoms in H-bonds...

  1. Phthalimides: Supramolecular Interactions in Crystals, Hypersensitive Solution 1H-NMR Dynamics and Energy Transfer to Europium(III and Terbium(III States

    David J. Williams

    2003-07-01

    Full Text Available Detailed crystal structures and 1H-NMR characteristics of some alkylaminephthalimides, including dendritic polyphthalimides, are reported. These investigations were undertaken in order to obtain a better understanding of the relationship between solid-state supramolecular interactions, their persistence in solution and associated dynamics of magnetically hypersensitive phthalimide aromatic AA'BB'-AA'XX' proton NMR resonances. Some alkylamine phthalimides feature folded molecular geometries, which we attribute to n-π interactions among proximal amine-phthalimide sites; those alkylamine-phthalimides that have no possibility for such interactions feature fully extended phthalimide functionalities. Accordingly, alkylamine phthalimide compounds with folded solid-state geometries feature solvent and temperature dependent hypersensitive AA'BB'-AA'XX' 1H-NMR line profiles, which we attribute to the n-π interactions. Luminescence of Eu3+(5D0 and Tb3+(5D4 states show well defined metal ion environments in their complexes with dendritic phthalimides, as well as relatively weak phthalimide-lanthanide(III interactions.

  2. 1H NMR Measurements of Wet/Dry Ratio and T1, T2Distributions in Lung

    Estilaei, Mohammadreza; MacKay, Alex; Roberts, Clive; Mayo, John

    1997-02-01

    Proton-magnetic-resonance measurements have been carried out on juvenile porcine peripheral lung parenchyma. The free-induction-decay signal contained a motionally restricted component which decayed in a few tens of microseconds and a mobile component with aT2time greater than 1 ms. The average second moment,M2, for the motionally restricted signal was found to be 3.42 ± (0.25) × 109s-2. TheT2distribution for the mobile signal consistently showed four resolvable components ofT2range: 2-6, 10-40, 80-110, and 190-400 ms. The 2-6 ms component was present in a fully dehydrated preparation and was therefore assigned to a nonaqueous lung constituent. The motionally restricted FID component had aT1= 0.772 ± 0.11 s and the mobile component had aT1= 0.967 ± 0.02 s. The hydrogen content per unit mass for lung parenchyma and water were estimated in two ways: (1) on the basis of chemical content and (2) on the basis of comparison of restricted and mobile signals to the gravimetric (G) water content for a lung sample studied at a wide range of water contents. Lung wet/dry weight ratios were estimated from the free-induction decays and compared with gravimetric measurement. The ratio of (wet/dry)NMR/(wet/dry)Gwas 1.00 ± 0.08 and 1.00 ± 0.05 for the two methods of estimation.

  3. Characterization of cellulose acetate obtained from sugarcane bagasse by {sup 1}H-NMR; Caracterizacao de acetato de celulose obtido a partir do bagaco de cana-de-acucar por {sup 1}H-RMN

    Cerqueira, Daniel A.; Rodrigues Filho, Guimes, E-mail: d.a.cerqueira@gmail.co [Universidade Federal de Uberlendia (IQ/UFU), MG (Brazil). Inst. de Quimica; Carvalho, Rui A. [Universidade de Coimbra (UC) (Portugal). Dept. de Bioquimica; Valente, Artur J.M. [Universidade de Coimbra (UC) (Portugal). Dept. de Quimica

    2009-07-01

    Cellulose from sugarcane bagasse was used for synthesizing cellulose acetate with different degrees of substitution, which were characterized by {sup 1}H-NMR through the relationship between the peak areas of the hydrogen atoms present at the acetate groups (-(C=O)OCH{sub 3} ) and the peaks of the hydrogen bonded to the carbon atoms of the glycosidic rings. Suppression was carried out in order to remove the peak of residual water in the materials and the peak related to impurities in cellulose triacetate. Degree of substitution values obtained through the resonance deconvolution were compared to those obtained by chemical determination through an acid-base titration. The determined degrees of substitution of the cellulose samples were 2.94 and 2.60. (author)

  4. The conformational stability, solvation and the assignments of the experimental infrared, Raman, 1H and 13C NMR spectra of the local anesthetic drug lidocaine

    Badawi, Hassan M.; Förner, Wolfgang; Ali, Shaikh A.

    2015-05-01

    The structure, vibrational and 1H and 13C NMR spectra of the local anesthetic drug lidocaine were investigated by the B3LYP/6-311G∗∗ calculations. The molecule was predicted to have the non-planar cis (NCCN ∼ 0°) structures being about 2-6 kcal/mol lower in energy than the corresponding trans (NCCN ∼ 180°) forms. The calculated NCCN (9.6°) and CNCC (-132.2°) torsional angles were in a good qualitative agreement with the reported X-ray angles (3.1 and 13.0°, -102.67 and -77.9°, respectively, for H-bonded dimers). The Gibbs energy of solution of lidocaine in formamide, water, dimethylsulfoxide, acetonitrile, methanol, ethanol and chloroform solutions was estimated at the B3LYP level. The predicted affinity of lidocaine toward the alcohols, acetonitrile and chloroform solutions was in excellent agreement with the reported experimental solubility of the drug in organic solvents. The analysis of the observed vibrational spectra is consistent with the presence of lidocaine in only one conformation at room temperature. The 1H and 13C NMR spectra of lidocaine were interpreted by experimental and DFT calculated chemical shifts of the drug. The RMSD between experimental and theoretical 1H and 13C chemical shifts for lidocaine is 0.47 and 8.26 ppm, respectively.

  5. Uniform procedure of (1)H NMR analysis of rat urine and toxicometabonomics Part II: comparison of NMR profiles for classification of hepatotoxicity.

    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

  6. Validation of quantitative {sup 1}H NMR method for the analysis of pharmaceutical formulations; Validacao de metodo quantitativo por RMN de {sup 1}H para analises de formulacoes farmaceuticas

    Santos, Maiara da S. [Universidade de Sao Paulo (USP), Sao Carlos, SP (Brazil). Instituto de Quimica; Colnago, Luiz Alberto, E-mail: luiz.colnago@embrapa.br [Embrapa Instrumentacao, Sao Carlos, SP (Brazil)

    2013-09-01

    The need for effective and reliable quality control in products from pharmaceutical industries renders the analyses of their active ingredients and constituents of great importance. This study presents the theoretical basis of Superscript-One H NMR for quantitative analyses and an example of the method validation according to Resolution RE N. 899 by the Brazilian National Health Surveillance Agency (ANVISA), in which the compound paracetamol was the active ingredient. All evaluated parameters (selectivity, linearity, accuracy, repeatability and robustness) showed satisfactory results. It was concluded that a single NMR measurement provides structural and quantitative information of active components and excipients in the sample. (author)

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

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

    2015-09-01

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

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

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

    2010-01-01

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

  9. On the Traceability of Commercial Saffron Samples Using 1H-NMR and FT-IR Metabolomics

    Roberto Consonni; ORDOUDI, Stella A; Laura R. Cagliani; Maria Tsiangali; TSIMIDOU, Maria Z

    2016-01-01

    In previous works on authentic samples of saffron of known history (harvest and processing year, storage conditions, and length of time) some biomarkers were proposed using both FT-IR and NMR metabolomics regarding the shelf life of the product. This work addresses the difficulties to trace back the “age” of commercial saffron samples of unknown history, sets a limit value above which these products can be considered substandard, and offers a useful tool to combat saffron mislabeling and frau...

  10. 1 H and 13 C NMR of dipyridamole derivatives in homogeneous solution: correlation to the electron density

    Dipyridamole, 2,6-bis(diethanolamino)-4,8-dipiperidino-pyrimido-pyrimidine, (DIP) has been widely used as a drug. The biological activity of this drug depends largely upon the nature of the substituents. In the present work, data on hydrogen-1 and carbon-13 NMR of DIP and some of its derivates are analysed in order to improve the knowledge of physico-chemical properties of these compounds. The methodology is presented. Results are reported and discussed

  11. 1H and 23Na MAS NMR spectroscopy of cationic species in CO2 selective alkaline earth metal porous silicoaluminophosphates prepared via liquid and solid state ion exchange

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

    2012-07-01

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

  12. Inductively coupled NMR probe for versatile dynamic nuclear polarization operation at 7 T: Observation of 61 ± 2% 1H polarization at 4 K

    Siaw, Ting Ann; Walker, Shamon A.; Armstrong, Brandon D.; Han, Song-I.

    2012-08-01

    We have performed dynamic nuclear polarization (DNP) experiments at liquid helium temperatures using a low-power (probe for the detection of 1H NMR signal at 300 MHz, as such coils are well suited for higher frequency NMR detection. The Alderman-Grant coil is inductively coupled to the rest of the radiofrequency (rf) circuit, whose design allows probe components to be placed away from the sample area, and also enables easy switching of coils with different diameters and resonance frequencies. We have tested our DNP instrument on a frozen nitroxide model system consisting of 4-Amino TEMPO dissolved in a glycerol:water mixture. The largest nuclear spin polarization observed was 61 ± 2% with a sample containing 20 mM 4-Amino TEMPO dissolved in deuterated glycerol (d-glycerol):D2O:H2O (50:40:10), amounting to record polarization measured to date at an easily amenable temperature of 4 K.

  13. Spectroscopic (FT-IR, FT-Raman, UV, 1H and 13C NMR) profiling and theoretical calculations of (2E)-2-[3-(1H-imidazol-1-yl)-1-phenylpropylidene]hydrazinecarboxamide: An anticonvulsant agent

    Haress, Nadia G.; Govindarajan, Munusamy; AL-Wabli, Reem I.; Almutairi, Maha S.; Al-Alshaikh, Monirah A.; Al-Saadi, Abdulaziz A.; Attia, Mohamed I.

    2016-08-01

    Vibrational characteristics of the anticonvulsant agent, (2E)-2-[3-(1H-imidazol-1-yl)-1-phenylpropylidene]hydrazinecarboxamide ((2E)-IPHC) have been investigated. The computational data are obtained by adopting ab initio Hartree-Fock (HF) and DFT/B3LYP/6-31 + G(d,p) methods. The most stable conformer is identified by a potential energy scan. The optimized geometrical parameters indicated that the overall symmetry of the most stable conformer is CS. Atoms in molecules (AIM) analysis is contained out and the chemical bondings between the atoms are as characterized. Mulliken atomic charges and simulated thermo-molecular (heat capacity and enthalpy) characteristics of the (2E)-IPHC molecule also have been analyzed. The magnitude of the molecular electrostatic potential (MEP) of oxygen, hydrogen, and nitrogen atoms as well as phenyl and imidazole rings in the title molecule were investigated along with their contribution to the biological activity. The energy gap between HOMO and LUMO orbitals has been found to be 5.1334 eV in the gaseous phase. Excitation energies, oscillator strength and wavelengths were computed by the time-dependent density function theory (TD-DFT) approach. Predicted wavenumbers have been assigned and they are consistent with the experimental values. The 1H and 13C nuclear magnetic resonance (NMR) chemical shifts of the (2E)-IPHC molecule were computed by the gauge independent atomic orbital (GIAO) method and were compared with the experimental results.

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

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

    2016-07-01

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

  15. 1H and 23Na MAS NMR spectroscopy of cationic species in CO2 selective alkaline earth metal porous silicoaluminophosphates prepared via liquid and solid state ion exchange

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

  16. Synthesis and NMR Spectral Analysis of Amine Heterocycles: The Effect of Asymmetry on the [superscript 1]H and [superscript 13]C NMR Spectra of N,O-Acetals

    Saba, Shahrokh; Ciaccio, James A.; Espinal, Jennifer; Aman, Courtney E.

    2007-01-01

    The stereochemical investigation is conducted to give students the combined experience of chemical synthesis of amines and N-heterocycles and structural stereochemical analysis using NMR spectroscopy. Students are introduced to the concept of topicity-stereochemical relationships between ligands within a molecule by synthesizing N,O-acetals.

  17. Absolute configuration and enantiomeric composition of partially resolved mandelic, atrolactic and lactic acids by {sup 1}H NMR of their (S)-2-methylbutyl esters

    Andrade, Francisco A. da C.; Mendes, Maricleide P. de L.; Fonseca, Neuracy C. da, E-mail: fandrade@ufba.br [Universidade Federal da Bahia (UFBA), Salvador, BA (Brazil). Instituto de Quimica. Departamento de Quimica Organica

    2013-06-15

    The mandelic, atrolactic and lactic acid esters of the (S)-2-methyl-1-butanol were examined as diastereomeric derivatives for the stereochemical analysis of the mentioned acids by {sup 1}H nuclear magnetic resonance (NMR) at 300 MHz. The diastereomeric esters showed distinctive signals in the methylenic absorption range (O-CH{sub 2}-CH) of the alcoholic moieties. By spectral analysis at this region, absolute configurations were attributed, chemical shifts of the correspondent pro-(R) and pro-(S) hydrogens from the methylene group of the alcohol moiety were assigned and enantiomeric compositions were determined for the original partially resolved acids. (author)

  18. {sup 1}H and {sup 10}B NMR and MRI investigation of boron- and gadolinium-boron compounds in boron neutron capture therapy

    Bonora, M., E-mail: marco.bonora@unipv.it [Physics Department ' A. Volta' , University of Pavia, Via Bassi 6, 27100 Pavia (Italy)] [CNISM Unit (Italy); Corti, M.; Borsa, F. [Physics Department ' A. Volta' , University of Pavia, Via Bassi 6, 27100 Pavia (Italy)] [CNISM Unit (Italy); Bortolussi, S.; Protti, N.; Santoro, D.; Stella, S.; Altieri, S. [Nuclear and Theoretical Physics Department, University of Pavia, Via Bassi 6, 27100 Pavia (Italy)] [INFN Pavia (Italy); Zonta, C.; Clerici, A.M.; Cansolino, L.; Ferrari, C.; Dionigi, P. [Surgical Sciences Department, Experimental Surgery Laboratory, University of Pavia, Pavia (Italy); Porta, A.; Zanoni, G.; Vidari, G. [Organic Chemistry Department, University of Pavia, Via Taramelli 10, 27100 Pavia (Italy)

    2011-12-15

    {sup 10}B molecular compounds suitable for Boron Neutron Capture Therapy (BNCT) are tagged with a Gd(III) paramagnetic ion. The newly synthesized molecule, Gd-BPA, is investigated as contrast agent in Magnetic Resonance Imaging (MRI) with the final aim of mapping the boron distribution in tissues. Preliminary Nuclear Magnetic Resonance (NMR) measurements, which include {sup 1}H and {sup 10}B relaxometry in animal tissues, proton relaxivity of the paramagnetic Gd-BPA molecule in water and its absorption in tumoral living cells, are reported.

  19. Absolute configuration and enantiomeric composition of partially resolved mandelic, atrolactic and lactic acids by 1H NMR of their (S)-2-methylbutyl esters

    The mandelic, atrolactic and lactic acid esters of the (S)-2-methyl-1-butanol were examined as diastereomeric derivatives for the stereochemical analysis of the mentioned acids by 1H nuclear magnetic resonance (NMR) at 300 MHz. The diastereomeric esters showed distinctive signals in the methylenic absorption range (O-CH2-CH) of the alcoholic moieties. By spectral analysis at this region, absolute configurations were attributed, chemical shifts of the correspondent pro-(R) and pro-(S) hydrogens from the methylene group of the alcohol moiety were assigned and enantiomeric compositions were determined for the original partially resolved acids. (author)

  20. Experimental and theoretical NMR study of 4-(1-pyrrolidinylpiperidine

    Metin Bilge

    2011-12-01

    Full Text Available The possible stable forms and molecular structure of 4-(1-pyrrolidinylpiperidine (4-pypp have been studied experimentally and theoretically using nuclear magnetic resonance (NMR spectroscopy. 1H, 13C, 15N, DEPT, COSY and HETCOR NMR spectra of 4-pypp (C9H18N2 have been reported. Solvent effects on nuclear magnetic shielding tensors have been investigated using chloroform-d, methanol-d, acetone-d, dimethylsulfoxide-d and water-d. The magnitude of nJ(C,H (n = 1, 2, 3 coupling constants of 4-pypp have been determined with selective 1H decoupled 13C NMR techniques. 1H, 13C, 15N NMR chemical shifts and 1-3J(C,H coupling constants have also been calculated for the most stable two conformers, equatorial-equatorial (e-e and axial-equatorial (a-e forms of 4-pypp using DFT/6-311++G(d,p//6-31G(d level of theory. Results from experimental and theoretical data have showed that the molecular geometry and the mole fractions of stable conformers of 4-pypp are solvent dependent.

  1. 1H-MAS-NMR Chemical Shifts in Hydrogen-Bonded Complexes of Chlorophenols (Pentachlorophenol, 2,4,6-Trichlorophenol, 2,6-Dichlorophenol, 3,5-Dichlorophenol, and p-Chlorophenol and Amine, and H/D Isotope Effects on 1H-MAS-NMR Spectra

    Hisashi Honda

    2013-04-01

    Full Text Available Chemical shifts (CS of the 1H nucleus in N···H···O type hydrogen bonds (H-bond were observed in some complexes between chlorophenols [pentachlorophenol (PCP, 2,4,6-tricholorophenol (TCP, 2,6-dichlorophenol (26DCP, 3,5-dichlorophenol (35DCP, and p-chlorophenol (pCP] and nitrogen-base (N-Base by solid-state high-resolution 1H-NMR with the magic-angle-spinning (MAS method. Employing N-Bases with a wide range of pKa values (0.65–10.75, 1H-MAS-NMR CS values of bridging H atoms in H-bonds were obtained as a function of the N-Base’s pKa. The result showed that the CS values were increased with increasing pKa values in a range of DpKa 2: The maximum CS values was recorded in the PCP (pKa = 5.26–4-methylpyridine (6.03, TCP (6.59–imidazole (6.99, 26DCP (7.02–2-amino-4-methylpyridine (7.38, 35DCP (8.04–4-dimethylaminopyridine (9.61, and pCP (9.47–4-dimethylaminopyridine (9.61 complexes. The largest CS value of 18.6 ppm was recorded in TCP–imidazole crystals. In addition, H/D isotope effects on 1H-MAS-NMR spectra were observed in PCP–2-amino-3-methylpyridine. Based on the results of CS simulation using a B3LYP/6-311+G** function, it can be explained that a little changes of the N–H length in H-bond contribute to the H/D isotope shift of the 1H-MAS-NMR peaks.

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

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

    2015-01-01

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

  3. Nitrogen-15 labeled 5S RNA. Identification of uridine base pairs in Escherichia coli 5S RNA by 1H-15N multiple quantum NMR

    Escherichia coli 5S RNA labeled with 15N at N3 of the uridines was isolated from the Sφ-187 uracil auxotroph grown on a minimal medium supplemented with [3-15N]uracil. 1H-15N multiple quantum filtered and 2D chemical shift correlated spectra gave resonances for the uridine imino 1H-15N units whose protons were exchanging slowly with solvent. Peaks with 1H/15N shifts at 11.6/154.8, 11.7/155.0, 11.8/155.5, 12.1/155.0, and 12.2/155.0 ppm were assigned to GU interactions. Two labile high-field AU resonances at 12.6/156.8 and 12.8/157.3 ppm typical of Au pairs in a shielded environment at the end of a helix were seen. Intense AU signals were also found at 13.4/158.5 and 13.6/159.2 ppm where 1H-15N units in normal Watson-Crick pairs resonate. 1H resonances at 10.6 and 13.8 ppm were too weak, presumably because of exchange with water, to give peaks in chemical shift correlated spectra. 1H chemical shifts suggest that the resonance at 13.8 ppm represents a labile AU pair, while the resonance at 10.6 ppm is typical of a tertiary interaction between U and a tightly bound water or a phosphate residue. The NMR data are consistent with proposed secondary structures for 5S RNA

  4. Flavonoids from Lonchocarpus araripensis (Leguminoseae): isolation, unequivocal assignment of NMR signals 1H and 13C and conformational analysis

    In a continuing investigation for potentially bioactive natural products, flavonoids were isolated from Lonchocarpus araripensis (Leguminoseae) and identified as 3-methoxy-6-O-prenyl-6'',6''-dimethylchromene-[7,8,2'',3'']-flavone (1), 3,6-dimethoxy-6'',6''-dimethylchromene-[7,8,2'',3'']-flavone (2) and 3,5,8-trimethoxy-[6,7,2,3]-furanoflavone (3). This is the first time compound 3 has been described. Compound 2 has been previously isolated from roots while this is the first time 1 is reported in this species. Complete NMR assignments are given for 1 ,2 and 3 together with the determination of conformation for 1. (author)

  5. Quantitative 1H NMR metabolomics reveals extensive metabolic reprogramming of primary and secondary metabolism in elicitor-treated opium poppy cell cultures

    Vogel Hans J

    2008-01-01

    Full Text Available Abstract 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

  6. Artificial neural networks for classification in metabolomic studies of whole cells using 1H nuclear magnetic resonance.

    Brougham, D F

    2011-01-01

    We report the successful classification, by artificial neural networks (ANNs), of (1)H NMR spectroscopic data recorded on whole-cell culture samples of four different lung carcinoma cell lines, which display different drug resistance patterns. The robustness of the approach was demonstrated by its ability to classify the cell line correctly in 100% of cases, despite the demonstrated presence of operator-induced sources of variation, and irrespective of which spectra are used for training and for validation. The study demonstrates the potential of ANN for lung carcinoma classification in realistic situations.

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

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

    1994-12-31

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

  8. NMR studies of oriented molecules

    Sinton, S.W.

    1981-11-01

    Deuterium and proton magnetic resonance are used in experiments on a number of compounds which either form liquid crystal mesophases themselves or are dissolved in a liquid crystal solvent. Proton multiple quantum NMR is used to simplify complicated spectra. The theory of nonselective multiple quantum NMR is briefly reviewed. Benzene dissolved in a liquid crystal are used to demonstrate several outcomes of the theory. Experimental studies include proton and deuterium single quantum (..delta..M = +-1) and proton multiple quantum spectra of several molecules which contain the biphenyl moiety. 4-Cyano-4'-n-pentyl-d/sub 11/-biphenyl (5CB-d/sub 11/) is studied as a pure compound in the nematic phase. The obtained chain order parameters and dipolar couplings agree closely with previous results. Models for the effective symmetry of the biphenyl group in 5CB-d/sub 11/ are tested against the experimental spectra. The dihedral angle, defined by the planes containing the rings of the biphenyl group, is found to be 30 +- 2/sup 0/ for 5DB-d/sub 11/. Experiments are also described for 4,4'-d/sub 2/-biphenyl, 4,4' - dibromo-biphenyl, and unsubstituted biphenyl.

  9. Synthesis of biodiesel from rocket seed oil and its characterization by FT-IR, NMR (/sup 1/H and /sup 13/C) and GC-MS

    The limited resources of fossil fuel, increasing prices of crude oils and environmental concerns have motivated the researcher for alternate fuels, such as bio diesel that is obtained from vegetable oils. Therefore, bio diesel was synthesized from Rocket seed oil by base catalyzed transesterification with methanol. The physical parameters like dynamic viscosity (3.88 cp), specific gravity (0.893 g cm/sup 3/), kinematic viscosity (5.85 mm/sup 2/s/sup 1/)), density (0.877 g cm/sup 3/), cloud point (3 deg. C), flash point (110 deg. C) and acid number (0.07 mg KOH g/sup 1/) of the synthesized rocket seed oil bio diesel (RSOB) were determined and were found to be comparable with ASTM recommended values for diesels. Chemical composition of the bio diesels formed was determined by various techniques like Fourier transform infrared (FTIR) spectroscopy, nuclear magnetic resonance (NMR) spectroscopy (/sup 1/H, 13/C) and gas chromatography-mass spectrometry (GCMS). The /sup 1/H NMR spectrum of RSOB is given. (Orig./A.B.)

  10. (1)H NMR and GC-MS Based Metabolomics Reveal Defense and Detoxification Mechanism of Cucumber Plant under Nano-Cu Stress.

    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

  11. {sup 1}H NMR determination of hypericin and pseudohypericin in complex natural mixtures by the use of strongly deshielded OH groups

    Tatsis, Evangelos C. [Section of Organic Chemistry and Biochemistry, Department of Chemistry, University of Ioannina, Ioannina, GR-45110 (Greece); Exarchou, Vassiliki [NMR Center, University of Ioannina, Ioannina, GR-45110 (Greece); Troganis, Anastassios N. [Department of Biological Applications and Technologies, University of Ioannina, Ioannina, GR-45110 (Greece); Gerothanassis, Ioannis P. [Section of Organic Chemistry and Biochemistry, Department of Chemistry, University of Ioannina, Ioannina, GR-45110 (Greece)], E-mail: igeroth@cc.uoi.gr

    2008-01-28

    The {sup 1}H NMR spectra of the commercially available compounds hypericin and its derivative pseudohypericin in CD{sub 3}OH solutions indicate significantly deshielded signals in the region of 14-15 ppm. These resonances are attributed to the peri hydroxyl protons OH(6), OH(8) and OH(1), OH(13) of hypericins which participate in a strong six-membered ring intramolecular hydrogen bond with CO(7) and CO(14), respectively, and therefore, they are strongly deshielded. In the present work, we demonstrate that one-dimensional {sup 1}H NMR spectra of hypericin and pseudohypericin, in Hypericum perforatum extracts show important differences in the chemical shifts of the hydroxyl groups with excellent resolution in the region of 14-15 ppm. The facile identification and quantification of hypericin and its derivative compound pseudohypericin was achieved, without prior HPLC separation, for two H. perforatum extracts from Greek cultivars and two commercial extracts: a dietary supplement, and an antidepressant medicine. The results were compared with those obtained from UV-vis and LC/MS measurements.

  12. (1)H NMR spectroscopic elucidation in solution of the kinetics and thermodynamics of spin crossover for an exceptionally robust Fe(2+) complex.

    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

  13. Solid state NMR study calcium phosphate ceramics

    High-resolution 31P and 1H NMR spectra at 40 and 121 MHz 31P and 300 MHz 1H of synthetic and biological samples of calcium phosphates have been obtained by magic angle spinning (MAS) at spinning speeds up to 6.5 kHz, and high power proton decoupling. The samples include crystalline hydroxyapatite, a deficient hydroxyapatite characterized by a Ca/P atomic ratio of 1.5, a poorly crystallized hydroxyapatite, monetite, brushite, octacalcium phosphate, β-tricalcium phosphate and rabbit femoral bone. The interactions between nuclei in unlike structures and the mobility of acid protons are discussed. (author). 11 refs.; 2 figs.; 1 tab

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

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

    2016-05-30

    Salvianolate Lyophilized Injection (SLI), a traditional Chinese medicinal (TCM) preparation which is used to treat stroke, is composed of multiple salvianolic acids from the aqueous extracts of Salvia miltiorrhiza, and includes mainly protocatechualdehyde, rosmarinic acid, salvianolic acid B, salvianolic acid D, salvianolic acid E, diastereomer of salvianolic acid E, salvianolic acid Y, lithospermic acid and diastereomer of lithospermic acid. It is difficult to quantitatively control the quality of SLI using traditional high performance liquid chromatography due to the highly similar structure of these constituents including three pairs of diastereomers and the lack of commercial resources for most of these constituents as standards. Thus, a highly reproducible, fast, accurate and simple (1)H quantitative nuclear magnetic resonance (qNMR) method without the need for calibration curves and complex computation was established by optimizing the solvent system and acquisition parameters to simultaneously determine the nine salvianolic acids and mannitol in SLI. This method was validated and successfully used to determine 10 batches of SLI and the qNMR data were further analyzed with a vector including angle cosine and the partial least squares method for the quality control of SLI. The results indicated that qNMR can be used as a routine method for the quality control of SLI and may have potential in the quantification of diastereomers in other TCM preparations. PMID:26970983

  15. Metabolic effects of dinoseb, diazinon and esfenvalerate in eyed eggs and alevins of Chinook salmon (Oncorhynchus tshawytscha) determined by 1H NMR metabolomics

    Pesticide pulses in the Sacramento River, California, originate from storm-water discharges and non-point source aquatic pollution that can last from a few days to weeks. The Sacramento River and its tributaries have historically supported the majority of California's Chinook salmon (Oncorhynchus tshawytscha) spawning grounds. Three pesticides currently used in the Sacramento Valley - dinoseb, diazinon, and esfenvalerate - were chosen to model the exposure of salmon embryos to storm-water discharges. Static-renewal (96 h) exposures to eyed eggs and alevins resulted in both toxicity and significant changes in metabolism assessed in whole-embryo extracts by 1H nuclear magnetic resonance (NMR) spectroscopy based metabolomics and HPLC with UV detection (HPLC-UV). The 96-h LC5 values of eyed eggs and alevins exposed to dinoseb were 335 and 70.6 ppb, respectively, and the corresponding values for diazinon were 545 and 29.5 ppm for eyed eggs and alevins, respectively. The 96-h LC5 of eyed eggs exposed to esfenvalerate could not be determined due to lack of mortality at the highest exposure concentration, but in alevins was 16.7 ppb. All esfenvalerate exposed alevins developed some degree of lordosis or myoskeletal abnormality and did not respond to stimulus or exhibit normal swimming behavior. ATP concentrations measured by HPLC-UV decreased significantly in eyed eggs due to 250 ppb dinoseb and 10 and 100 ppb esfenvalerate (p 1H NMR metabolite fingerprints of eyed egg and alevin extracts revealed both dose-dependent and mechanism of action-specific metabolic effects induced by the pesticides. Furthermore, NMR based metabolomics proved to be more sensitive than HPLC-UV in identifying significant changes in sublethal metabolism of pesticide exposed alevins. In conclusion, we have demonstrated several benefits of a metabolomics approach for chemical risk assessment, when used in conjunction with a fish embryo assay, and have identified significant metabolic perturbations to

  16. NMR study of metal-hydrogen systems for hydrogen storage

    Research highlights: → Proton NMR provides information on hydrogen mobility in metal hydrides. → In Ti-V-Cr the relaxation rates strongly depend on the vanadium fraction. → The activation processes start earlier for the vanadium reach hydrides. → Addition of Zr-Ni or Hf-Ni alloys enhances the hydrogen mobility in Ti-V-Cr. - Abstract: In this contribution we report on the results of our recent 1H NMR studies of different metal hydrides of interest for reversible hydrogen storage applications: Ti-V-Cr alloys of various compositions, pure and with Zr7Ni10 or Hf7Ni10 additives, and in additives themselves. The temperature dependences of 1H spin-lattice relaxation have been treated within an exchange model.

  17. NMR-Metabolic Methodology in the Study of GM Foods

    Irene D’Amico

    2010-01-01

    Full Text Available The 1H-NMR methodology used in the study of genetically modified (GM foods is discussed. Transgenic lettuce (Lactuca sativa cv "Luxor" over-expressing the Arabidopsis KNAT1 gene is presented as a case study. Twenty-two water-soluble metabolites (amino acids, organic acids, sugars present in leaves of conventional and GM lettuce were monitored by NMR and quantified at two developmental stages. The NMR spectra did not reveal any difference in metabolite composition between the GM lettuce and the wild type counterpart. Statistical analyses of metabolite variables highlighted metabolism variation as a function of leaf development as well as the transgene. A main effect of the transgene was in altering sugar metabolism.

  18. Parahydrogen induced polarization of barbituric acid derivatives: 1H hyperpolarization studies.

    Roth, Meike; Bargon, Joachim; Spiess, Hans Wolfgang; Koch, Achim

    2008-08-01

    Homogeneous hydrogenation of barbituric acid derivatives with parahydrogen yields a substantial increase of the (1)H NMR signals of the reaction products. These physiologically relevant compounds were hydrogenated at both ambient and elevated temperatures and pressures using a standard cationic rhodium catalyst. The resulting nonthermal nuclear spin polarization (hyperpolarization) is limited by the spin-lattice relaxation time T(1) of the corresponding nuclei in the products, being shorter than the time constant of the hydrogenation. The signal-to-noise ratio of the NMR spectra could be further increased upon signal averaging the antiphase PHIP signals of 25 successive scans following 30 degrees pulse experiments and a delay of 10 s. PMID:18470863

  19. Predictability of 1-h postload plasma glucose concentration: A 10-year retrospective cohort study

    Kuang, Lifen; Huang, Zhimin; Hong, Zhenzhen; Chen, Ailing; Li, Yanbing

    2015-01-01

    Aims/Introduction Elevated 1-h postload plasma glucose concentration (1hPG) during oral glucose tolerance test has been linked to an increased risk of type 2 diabetes and a poorer cardiometabolic risk profile. The present study analyzed the predictability and cut-off point of 1hPG in predicting type 2 diabetes in normal glucose regulation (NGR) subjects, and evaluated the long-term prognosis of NGR subjects with elevated 1hPG in glucose metabolism, kidney function, metabolic states and athero...

  20. On the Traceability of Commercial Saffron Samples Using 1H-NMR and FT-IR Metabolomics

    Roberto Consonni

    2016-02-01

    Full Text Available In previous works on authentic samples of saffron of known history (harvest and processing year, storage conditions, and length of time some biomarkers were proposed using both FT-IR and NMR metabolomics regarding the shelf life of the product. This work addresses the difficulties to trace back the “age” of commercial saffron samples of unknown history, sets a limit value above which these products can be considered substandard, and offers a useful tool to combat saffron mislabeling and fraud with low-quality saffron material. Investigations of authentic and commercial saffron samples of different origin and harvest year, which had been stored under controlled conditions for different lengths of time, allowed a clear-cut clustering of samples in two groups according to the storage period irrespectively of the provenience. In this respect, the four-year cut off point proposed in our previous work assisted to trace back the “age” of unknown samples and to check for possible mislabeling practices.

  1. Assignment of histidine resonances in the 1H NMR (500 MHz) spectrum of subtilisin BPN' using site-directed mutagenesis

    A spin-echo pulse sequence has been used to resolve the six histidine C-2H protons in the 500-MHz NMR spectrum of subtilisin BPN'. Five of these residues have been substituted by site-directed mutagenesis, and this has enabled a complete assignment of these protons to be obtained. Analysis of the pH titration curves of these signals has provided microscopic pKa's for the six histidines in this enzyme. The pKa's of the histidine residues in subtilisin BPN' have been compared with the values obtained for the histidines in the homologous enzyme from Bacillus licheniformis (subtilisin Carlsberg). Four of the five conserved histidines titrate with essentially identical pKa's in the two enzymes. It therefore appears that the assignments made for these residues in subtilisin BPN' can be transferred to subtilisin Carlsberg. On the basis of these assignments, the one histidine that titrates with a substantially different pKa in the two enzymes can be assigned to histidine-238. This difference in pKa has been attributed to a Trp to Lys substitution at position 241 in subtilisin Carlsberg

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

    Angawi, Rihab F.

    2014-01-01

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

  3. 1H Nuclear Magnetic Resonance Relaxometry Study of Water State in Milk Protein Mixtures

    Le Dean, A.; Mariette, F.; Marin, M

    2004-01-01

    1H NMR signal was used to characterize highly hydrated milk protein dispersions (3-20% dry matter) with various micellar casein concentrations (3-15%), whey protein concentrations (0-3%), lactose concentrations (0-7.5%), CaCl2 concentrations (0-2 mM), and pH (6.2-6.6). The results showed the predominant effect of micellar casein concentration on water state and were consistent with the three-site relaxation model in the absence of lactose. The relaxation rates observed for these dispersions w...

  4. Magnetic hyperthermia efficiency and 1H-NMR relaxation properties of iron oxide/paclitaxel-loaded PLGA nanoparticles

    Ruggiero, Maria R.; Geninatti Crich, Simonetta; Sieni, Elisabetta; Sgarbossa, Paolo; Forzan, Michele; Cavallari, Eleonora; Stefania, Rachele; Dughiero, Fabrizio; Aime, Silvio

    2016-07-01

    Magnetic iron oxide nanoparticles (Fe-NPs) can be exploited in biomedicine as agents for magnetic fluid hyperthermia (MFH) treatments and as contrast enhancers in magnetic resonance imaging. New, oleate-covered, iron oxide particles have been prepared either by co-precipitation or thermal decomposition methods and incorporated into poly(lactic-co-glycolic acid) nanoparticles (PLGA-Fe-NPs) to improve their biocompatibility and in vivo stability. Moreover, the PLGA-Fe-NPs have been loaded with paclitaxel to pursue an MFH-triggered drug release. Remarkably, it has been found that the nanoparticle formulations are characterized by peculiar 1H nuclear magnetic relaxation dispersion (NMRD) profiles that directly correlate with their heating potential when exposed to an alternating magnetic field. By prolonging the magnetic field exposure to 30 min, a significant drug release was observed for PLGA-Fe-NPs in the case of the larger-sized magnetic nanoparticles. Furthermore, the immobilization of lipophilic Fe-NPs in PLGA-NPs also made it possible to maintain Néel relaxation as the dominant relaxation contribution in the presence of large iron oxide cores (diameters of 15–20 nm), with the advantage of preserving their efficiency when they are entrapped in the intracellular environment. The results reported herein show that NMRD profiles are a useful tool for anticipating the heating capabilities of Fe-NPs designed for MFH applications.

  5. Magnetic hyperthermia efficiency and (1)H-NMR relaxation properties of iron oxide/paclitaxel-loaded PLGA nanoparticles.

    Ruggiero, Maria R; Crich, Simonetta Geninatti; Sieni, Elisabetta; Sgarbossa, Paolo; Forzan, Michele; Cavallari, Eleonora; Stefania, Rachele; Dughiero, Fabrizio; Aime, Silvio

    2016-07-15

    Magnetic iron oxide nanoparticles (Fe-NPs) can be exploited in biomedicine as agents for magnetic fluid hyperthermia (MFH) treatments and as contrast enhancers in magnetic resonance imaging. New, oleate-covered, iron oxide particles have been prepared either by co-precipitation or thermal decomposition methods and incorporated into poly(lactic-co-glycolic acid) nanoparticles (PLGA-Fe-NPs) to improve their biocompatibility and in vivo stability. Moreover, the PLGA-Fe-NPs have been loaded with paclitaxel to pursue an MFH-triggered drug release. Remarkably, it has been found that the nanoparticle formulations are characterized by peculiar (1)H nuclear magnetic relaxation dispersion (NMRD) profiles that directly correlate with their heating potential when exposed to an alternating magnetic field. By prolonging the magnetic field exposure to 30 min, a significant drug release was observed for PLGA-Fe-NPs in the case of the larger-sized magnetic nanoparticles. Furthermore, the immobilization of lipophilic Fe-NPs in PLGA-NPs also made it possible to maintain Néel relaxation as the dominant relaxation contribution in the presence of large iron oxide cores (diameters of 15-20 nm), with the advantage of preserving their efficiency when they are entrapped in the intracellular environment. The results reported herein show that NMRD profiles are a useful tool for anticipating the heating capabilities of Fe-NPs designed for MFH applications. PMID:27265726

  6. Authenticity study of Phyllanthus species by NMR and FT-IR techniques coupled with chemometric methods

    Santos, Maiara S.; Pereira-Filho, Edenir R.; Ferreira, Antonio G. [Universidade Federal de Sao Carlos (UFSCAR), SP (Brazil). Dept. de Quimica; Boffo, Elisangela F. [Universidade Federal da Bahia (UFBA), Salvador, BA (Brazil). Inst. de Quimica; Figueira, Glyn M., E-mail: maiarassantos@yahoo.com.br [Universidade Estadual de Campinas (UNICAMP), Campinas, SP (Brazil). Centro Pluridisciplinar de Pesquisas Quimicas, Biologicas e Agricolas

    2012-07-01

    The importance of medicinal plants and their use in industrial applications is increasing worldwide, especially in Brazil. Phyllanthus species, popularly known as 'quebra-pedras' in Brazil, are used in folk medicine for treating urinary infections and renal calculus. This paper reports an authenticity study, based on herbal drugs from Phyllanthus species, involving commercial and authentic samples using spectroscopic techniques: FT-IR, {sup 1}H HR-MAS NMR and {sup 1}H NMR in solution, combined with chemometric analysis. The spectroscopic techniques evaluated, coupled with chemometric methods, have great potential in the investigation of complex matrices. Furthermore, several metabolites were identified by the NMR techniques. (author)

  7. Authenticity study of Phyllanthus species by NMR and FT-IR techniques coupled with chemometric methods

    The importance of medicinal plants and their use in industrial applications is increasing worldwide, especially in Brazil. Phyllanthus species, popularly known as 'quebra-pedras' in Brazil, are used in folk medicine for treating urinary infections and renal calculus. This paper reports an authenticity study, based on herbal drugs from Phyllanthus species, involving commercial and authentic samples using spectroscopic techniques: FT-IR, 1H HR-MAS NMR and 1H NMR in solution, combined with chemometric analysis. The spectroscopic techniques evaluated, coupled with chemometric methods, have great potential in the investigation of complex matrices. Furthermore, several metabolites were identified by the NMR techniques. (author)

  8. Structural comparison of complexes of methotrexate analogues with Lactobacillus casei dihydrofolate reductase by two-dimensional 1H NMR at 500 MHz

    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 1H 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 1H 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 γ-monoamide analog, the 1H 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 γ-CO2- is no longer present in this complex with the γ-amide, there has not been a major change in the overall structure of the two complexes. This behavior contrasts to that of the α-amide complex where 1H signals from protons in several amino acid residues are different compared with their values in the complex formed with methotrexate

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

    Meier, R.; Schneider, E.; Rössler, E. A. [Experimentalphysik II, Universität Bayreuth, D-95440 Bayreuth (Germany)

    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.

  10. NMR studies of isotopically labeled RNA

    Pardi, A. [Univ. of Colorado, Boulder, CO (United States)

    1994-12-01

    In summary, the ability to generate NMR quantities of {sup 15}N and {sup 13}C-labeled RNAs has led to the development of heteronuclear multi-dimensional NMR techniques for simplifying the resonance assignment and structure determination of RNAs. These methods for synthesizing isotopically labeled RNAs are only several years old, and thus there are still relatively few applications of heteronuclear multi-dimensional NMR techniques to RNA. However, given the critical role that RNAs play in cellular function, one can expect to see an increasing number of NMR structural studies of biologically active RNAs.

  11. Primidone - An antiepileptic drug - characterisation by quantum chemical and spectroscopic (FTIR, FT-Raman, 1H, 13C NMR and UV-Visible) investigations

    Arjunan, V.; Santhanam, R.; Subramanian, S.; Mohan, S.

    2013-05-01

    The solid phase FTIR and FT-Raman spectra of primidone were recorded in the regions 4000-400 cm-1 and 4000-100 cm-1, respectively. The vibrational spectra were analysed and the observed fundamentals were assigned and analysed. The experimental wavenumbers were compared with the theoretical scaled vibrational wavenumbers determined by DFT methods. The Raman intensities were also determined with B3LYP/6-31G(d,p) method. The total electron density and molecular electrostatic potential surface of the molecule were constructed by using B3LYP/6-311++G(d,p) method to display electrostatic potential (electron + nuclei) distribution. The HOMO and LUMO energies were measured. Natural bond orbital analysis of primidone has been performed to indicate the presence of intramolecular charge transfer. The 1H and 13C NMR spectra were recorded and the chemical shifts of the molecule were calculated.

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

    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

  13. Comparison of cooperative and isolated site binding of T4 gene 32 protein to ssDNA by 1H NMR

    Deuteriation of all aromatic protons of gene 32 protein (g32P) from phage T4, followed by selective introduction of specific protons, has allowed the precise identification of the number and magnitude of the chemical shift changes induced in the aromatic protons when g32P binds noncooperatively or cooperatively to nucleotides. Signals from five Tyr residues are shifted by binding of g32P to d(pA)8 or d(pA)40-60; however, the change from noncooperative, d(pA)8, to cooperative, d(pA)40-60, binding causes significant increases in the magnitudes of the shifts for only two of these Tyr signals. These two Tyr residues may interact directly with the nucleotide bases, while the shifts associated with the other three Tyr may be due to conformational changes in g32P upon ssDNA binding. Similar conclusions can be drawn for two of the six Phe residues whose protons undergo shifts upon nucleotide binding. Observation of selected proton signals allows for the first time detection by 1H NMR of changes in the proton signals from two Trp residues upon nucleotide binding. The side chains of two Tyr, one or two Phe, and one Trp are probably directly involved in nucleotide base-protein interactions. As assayed by the signals from the H2 and H8 protons of adenine, the bases of a bound nucleotide are undergoing a fast chemical exchange in the noncooperative mode of binding, but shift to slow exchange upon assuming the cooperative mode of ssDNA interaction. When bound to a polynucleotide, the A domain of g32P (residues 254-301) becomes more mobile, as reflected in sharpening of the 1H NMR signals from the A domain

  14. Hydrogen Bonding, (1)H NMR, and Molecular Electron Density Topographical Characteristics of Ionic Liquids Based on Amino Acid Cations and Their Ester Derivatives.

    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

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

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

  16. Determining the depth of insertion of dynamically invisible membrane peptides by gel-phase {sup 1}H spin diffusion heteronuclear correlation NMR

    Wang, T.; Yao, H.; Hong, M., E-mail: mhong@iastate.edu [Iowa State University, Department of Chemistry (United States)

    2013-06-15

    Solid-state NMR determination of the depth of insertion of membrane peptides and proteins has so far utilized {sup 1}H spin diffusion and paramagnetic relaxation enhancement experiments, which are typically conducted in the liquid-crystalline phase of the lipid bilayer. For membrane proteins or peptide assemblies that undergo intermediate-timescale motion in the liquid-crystalline membrane, these approaches are no longer applicable because the protein signals are broadened beyond detection. Here we show that the rigid-solid HETCOR experiment, with an additional spin diffusion period, can be used to determine the depth of proteins in gel-phase lipid membranes, where the proteins are immobilized to give high-intensity solid-state NMR spectra. Demonstration on two membrane peptides with known insertion depths shows that well-inserted peptides give rise to high lipid cross peak intensities and low water cross peaks within a modest spin diffusion mixing time, while surface-bound peptides have higher water than lipid cross peaks. Furthermore, well-inserted membrane peptides have nearly identical {sup 1}H cross sections as the lipid chains, indicating equilibration of the peptide and lipid magnetization. Using this approach, we measured the membrane topology of the {alpha}-helical fusion peptide of the paramyxovirus, PIV5, in the anionic POPC/POPG membrane, in which the peptide undergoes intermediate-timescale motion at physiological temperature. The gel-phase HETCOR spectra indicate that the {alpha}-helical fusion peptide is well inserted into the POPC/POPG bilayer, spanning both leaflets. This insertion motif gives insight into the functional role of the {alpha}-helical PIV5 fusion peptide in virus-cell membrane fusion.

  17. 1H HRMAS NMR spectroscopy and chemometrics for evaluation of metabolic changes in citrus sinensis Caused by Xanthomonas axonopodis pv. citri

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

  18. 2D NMR studies of biomolecules

    The work described in this thesis comprises two related subjects. The first part describes methods to derive high-resolution structures of proteins in solution using two-dimensional (2-D) NMR. The second part describes 2-D NMR studies on the interaction between proteins and DNA. (author). 261 refs.; 52 figs.; 23 tabs

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

    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

  20. Dynamics and ferroelectric phase transition of (C3N2H5)5Bi2Br11 by means of ac calorimetry and 1H NMR relaxometry

    Highlights: ► The excess entropy clearly confirms an ‘order–disorder’ mechanism assigned to the dynamics of the imidazolium cations. ► 1H NMR conformed dynamical heterogeneity of the imidazolium cations in low temperature phases. ► The paraelectric-ferroelectric transition at 155 K is close to the tricritical one. -- Abstract: A quite uncommon type of heat anomaly has been disclosed by calorimetric experiments in ferroelectric crystal (C3N2H5)5Bi2Br11 close to the paraelectric-ferroelectric transition. Thermal parameters (such as the excess enthalpy (ΔH) and the excess entropy (ΔS)) of the continuous ferroelectric phase transition at ca. 155 K have been estimated and discussed. The entropy transition accompanying the ferroelectric phase transition (PT) of the order of 35 J/mol K confirms an ‘order–disorder’ mechanism. The ferroelectric–paraelectric PT has been described by the Landau model using the specific heat data.1H spin–lattice relaxation at 25 MHz has been measured for this crystal in a very broad temperature range 90–420 K, covering two phase transitions (at 155 and 355 K). The relaxation data have been interpreted in terms of different dynamical properties of imidazolium cations put in structurally different environments.