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Sample records for 1h nmr metabolite

  1. 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...

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

    Ullrich, Sophie Friederike

    2016-07-01

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

  3. 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

  4. 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

  5. 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.

  6. 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

  7. 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

  8. 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

  9. 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

  10. 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

  11. 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.

  12. 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

  13. 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

  14. 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

  15. 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

  16. 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.

  17. 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.

  18. Micropreparative isolation and NMR structure elucidation of metabolites of the drug candidate 1-isopropyl-4-(4-isopropylphenyl)-6-(prop-2-yn-1-yloxy) quinazolin-2(1H)-one from rat bile and urine.

    Blanz, Joachim; Délémonté, Thierry; Pearson, David; Luneau, Alexandre; Ritzau, Michael; Gertsch, Werner; Ramstein, Philippe; Dayer, Jérôme; Desrayaud, Sandrine; Braun, Elisabeth; Aichholz, Reiner

    2015-05-01

    LC-MS based drug metabolism studies are effective in the optimization stage of drug discovery for rapid partial structure identification of metabolites. However, these studies usually do not provide unambiguous structural characterization of all metabolites, due to the limitations of MS-based structure identification. LC-MS-SPE-NMR is a technique that allows complete structure identification, but is difficult to apply to complex in vivo samples (such as bile collected during in vivo drug metabolism studies) due to the presence, at high concentrations, of interfering endogenous components, and potentially also dosage excipient components (e.g. polyethylene glycols). Here, we describe the isolation and structure characterization of seven metabolites of the drug development candidate 1-isopropyl-4-(4-isopropylphenyl)-6-(prop-2-yn-1-yloxy) quinazolin-2(1H)-one from a routine metabolism study in a bile-duct cannulated rat by LC-MS-SPE. The metabolites were isolated from bile and urine by repeated automatic trapping of the chromatographic peak of each metabolite on separate Oasis HLB SPE columns. The micropreparative HPLC/MS was performed on an XBridge BEH130 C18 HPLC column using aqueous formic acid/acetonitrile/methanol as mobile phase for the gradient elution. Mass spectrometric detection was performed on a LTQ XL linear ion trap mass spectrometer using electrospray ionization. Desorption of each metabolite was performed after the separation sequence. NMR spectra ((1)H, (13)C, 2D ROESY, HSQC and HMBC were measured on a Bruker AVANCE III spectrometer (600 MHz proton frequency) equipped with a 1.7 mm (1)H{(13)C,(15)N} Bruker Biospin's TCI MicroCryoProbe™. PMID:25797717

  19. Integrating candidate metabolites and biochemical factors to elucidate the action mechanism of Xue-sai-tong injection based on (1)H NMR metabolomics.

    Jiang, Miaomiao; Zhao, Xiaoping; Wang, Linli; Xu, Lei; Zhang, Yan; Li, Zheng

    2016-07-15

    A strategy of integrating candidate metabolites with crucial biochemical factors was proposed in this study to discover relevant biological functions for interpreting the action mechanism of Traditional Chinese Medicines (TCM). This approach was applied to Xue-Sai-Tong injection (XST) to reveal the action mechanism based on the metabolic response in an ischemia/reperfusion (I/R) rat model by analyzing NMR profile. Partial least squares discriminate analysis (PLS-DA) was used to compare metabolic profiles of serum samples and revealed nine metabolites altered by I/R injury could be restored to normal status (sham-operated group) under the therapy of XST. The pathway enrichment analysis suggested the metabolic changes were mainly involved in pyruvate metabolism, glycolysis, and citrate cycle. The functional roles of the candidate metabolites were further identified by Pearson correlation analysis with the key biochemical factors in serum. The results indicated pyruvate, succinate, acetate and lysine showed significant associations with the oxidative stress factors. Elevated level of pyruvate was found as an essential metabolic response for the major effect of XST against I/R injury by enhancing glycolysis and overcoming the induced reactive oxygen species (ROS). This metabolomics approach provides a better understanding of the mechanisms of TCM and helps to develop a holistic view of TCM efficacy. PMID:26862062

  20. Defence response of sitka spruce before and after inoculation with heterobasidion annosum: 1H NMR fingerprinting of bark and sapwood metabolites

    Metabolite fingerprinting of Sitka spruce (Picea sitchensis) bark and sapwood was carried out by 1H nuclear magnetic resonance after wounding and artificial inoculation with the white rot fungus Heterobasidion annosum sensu stricto. The aim was to determine whether metabolites would differ in clones showing differing levels of susceptibility to H. annosum, in the fungal as compared with the control treatment (wounding, no fungus) and the reference (healthy sample collected at 0 days), at two different locations on the host, and at different sampling times (3 and 43 days after treatment). The results suggested that different metabolic processes occur in bark and sapwood after wounding and fungal inoculation, compared with healthy samples collected before treatment: In bark, greater peaks were elicited in the aromatic region whereas, in sapwood, lower amounts of all metabolites were observed in inoculated samples, compared with healthy samples. Multivariate statistical analysis carried out with analysis of variance-principal component analysis showed highly significant effects of reference, location, and time (PC1), and significant effects of clone and fungus. Differences between clones were apparent in sapwood but not in bark and were due to peaks in the aliphatic and carbohydrate regions. Over time, in bark, there was a decrease in carbohydrate peaks, followed by an increase in aliphatic and aromatic peaks. Sapwood, by contrast, showed a decrease in all peaks, followed by an increase in carbohydrate and aliphatic peaks. Changes in carbohydrate levels were observed within the lesion compared with the more distal location in both bark and sapwood. (orig.)

  1. Defence response of sitka spruce before and after inoculation with heterobasidion annosum: {sup 1}H NMR fingerprinting of bark and sapwood metabolites

    Deflorio, Giuliana; Woodward, Stephen [University of Aberdeen, Department of Plant and Soil Science, Institute of Biological and Environmental Sciences, Aberdeen (United Kingdom); Horgan, Graham [Biomathematics and Statistics Scotland, Aberdeen (United Kingdom); Jaspars, Marcel [University of Aberdeen, Department of Chemistry, Marine Biodiscovery Centre, Aberdeen (United Kingdom)

    2012-04-15

    Metabolite fingerprinting of Sitka spruce (Picea sitchensis) bark and sapwood was carried out by {sup 1}H nuclear magnetic resonance after wounding and artificial inoculation with the white rot fungus Heterobasidion annosum sensu stricto. The aim was to determine whether metabolites would differ in clones showing differing levels of susceptibility to H. annosum, in the fungal as compared with the control treatment (wounding, no fungus) and the reference (healthy sample collected at 0 days), at two different locations on the host, and at different sampling times (3 and 43 days after treatment). The results suggested that different metabolic processes occur in bark and sapwood after wounding and fungal inoculation, compared with healthy samples collected before treatment: In bark, greater peaks were elicited in the aromatic region whereas, in sapwood, lower amounts of all metabolites were observed in inoculated samples, compared with healthy samples. Multivariate statistical analysis carried out with analysis of variance-principal component analysis showed highly significant effects of reference, location, and time (PC1), and significant effects of clone and fungus. Differences between clones were apparent in sapwood but not in bark and were due to peaks in the aliphatic and carbohydrate regions. Over time, in bark, there was a decrease in carbohydrate peaks, followed by an increase in aliphatic and aromatic peaks. Sapwood, by contrast, showed a decrease in all peaks, followed by an increase in carbohydrate and aliphatic peaks. Changes in carbohydrate levels were observed within the lesion compared with the more distal location in both bark and sapwood. (orig.)

  2. The Serum Metabolite Response to Diet Intervention with Probiotic Acidified Milk in Irritable Bowel Syndrome Patients Is Indistinguishable from that of Non-Probiotic Acidified Milk by 1H NMR-Based Metabonomic Analysis

    Ulla Svensson

    2010-11-01

    Full Text Available The effects of a probiotic acidified milk product on the blood serum metabolite profile of patients suffering from Irritable Bowel Syndrome (IBS compared to a non-probiotic acidified milk product was investigated using 1H NMR metabonomics. For eight weeks, IBS patients consumed 0.4 L per day of a probiotic fermented milk product or non-probiotic acidified milk. Both diets resulted in elevated levels of blood serum l-lactate and 3-hydroxybutyrate. Our results showed identical effects of acidified milk consumption independent of probiotic addition. A similar result was previously obtained in a questionnaire-based evaluation of symptom relief. A specific probiotic effect is thus absent both in the patient subjective symptom evaluations and at the blood serum metabolite level. However, there was no correspondence between symptom relief and metabolite response on the patient level.

  3. The Serum Metabolite Response to Diet Intervention with Probiotic Acidified Milk in Irritable Bowel Syndrome Patients Is Indistinguishable from that of Non-Probiotic Acidified Milk by 1H NMR-Based Metabonomic Analysis

    Ulla Svensson; Anders Malmendal; Bertram, Hanne C.; Magnus Simrén; Lena Öhman; Andersen, Henrik J.; Johan Olsson; Pedersen, Simon M. M.; Niels Chr. Nielsen

    2010-01-01

    The effects of a probiotic acidified milk product on the blood serum metabolite profile of patients suffering from Irritable Bowel Syndrome (IBS) compared to a non-probiotic acidified milk product was investigated using 1H NMR metabonomics. For eight weeks, IBS patients consumed 0.4 L per day of a probiotic fermented milk product or non-probiotic acidified milk. Both diets resulted in elevated levels of blood serum l-lactate and 3-hydroxybutyrate. Our results showed identical effects of acidi...

  4. 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

  5. 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.

  6. 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.

  7. 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

  8. Analysis of human urine metabolites using SPE and NMR spectroscopy

    2008-01-01

    Nuclear magnetic resonance (NMR) spectroscopic analysis of metabonome/metabolome has widespread applications in biomedical science researches. However, most of NMR resonances for urinary metabolites remain to be fully assigned. In the present study, human urine samples from two healthy volunteers were pre-treated with C18 solid-phase extraction and the resultant 5 sub-fractions were subjected to one- and two-dimensional NMR studies, including 1H J-Resolved, 1H-1H COSY, 1H-1H TOCSY, 1H-13C HSQC, and HMBC 2D NMR. More than 70 low molecular weight metabolites were identified, and complete assignments of 1H and 13C resonances including many complex coupled spin systems were obtained.

  9. An inter-laboratory comparison demonstrates that [1H]-NMR metabolite fingerprinting is a robust technique for collaborative plant metabolomic data collection

    Ward, Jane L.; Baker, John M.; Miller, Sonia J.; Deborde, Catherine; Maucourt, Mickael; Biais, Benoit; Rolin, Dominique; Moing, Annick; Moco, Sofia; Vervoort, Jacques; Lommen, Arjen; Schäfer, Hartmut; Humpfer, Eberhard; Beale, Michael H.

    2010-01-01

    In any metabolomics experiment, robustness and reproducibility of data collection is of vital importance. These become more important in collaborative studies where data is to be collected on multiple instruments. With minimisation of variance in sample preparation and instrument performance it is possible to elucidate even subtle differences in metabolite fingerprints due to genotype or biological treatment. In this paper we report on an inter laboratory comparison of plant derived samples b...

  10. 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...

  11. 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...

  12. 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 ...

  13. 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.

  14. 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...

  15. 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...

  16. 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

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

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

    2008-01-01

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

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

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

  19. 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.

  20. 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

  1. 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

  2. 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.

  3. (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

  4. 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.

  5. 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.

  6. 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

  7. 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...

  8. 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

  9. 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

  10. 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

  11. 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

  12. 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

  13. (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

  14. 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.

  15. 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

  16. Liver Metabolite Concentrations Measured with 1H MR Spectroscopy

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

    2012-01-01

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

  17. 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

  18. 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.

  19. 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.

  20. 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

  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. 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

  3. 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.

  4. Absolute quantification of calf muscle metabolites by proton 1H-MR spectroscopy

    measured at 3.0 T of the metabolites in skeletal muscles of healthy adult human. After corrected by the relaxation times, the absolute concentrations calculated were consistent with the reported results. Quantitative knowledge of muscle NMR relaxation time was a prerequisite for absolute quantification of metabolites using the 1H-MRS and also was useful for optimizing measurement protocols. (authors)

  5. 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

  6. 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.

  7. {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.

  8. 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

  9. 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

  10. 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.

  11. 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

  12. 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...

  13. 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

  14. 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.

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

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

    2007-11-30

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

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

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

  17. 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

  18. 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

  19. 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

  20. 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

  1. 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.

  2. 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

  3. 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.

  4. 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

  5. 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)

  6. 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

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

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

    2005-01-01

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

  8. (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

  9. 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.

  10. 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

  11. 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)

  12. Quantitative metabolite profiling of edible onion species by NMR and HPLC-MS.

    Soininen, Tuula H; Jukarainen, Niko; Auriola, Seppo O K; Julkunen-Tiitto, Riitta; Karjalainen, Reijo; Vepsäläinen, Jouko J

    2014-12-15

    Allium genus is a treasure trove of valuable bioactive compounds with potentially therapeutically important properties. This work utilises HPLC-MS and a constrained total-line-shape (CTLS) approach applied to (1)H NMR spectra to quantify metabolites present in onion species to reveal important inter-species differences. Extensive differences were detected between the sugar concentrations in onion species. Yellow onion contained the highest and red onion the lowest amounts of amino acids. The main flavonol-glucosides were quercetin 3,4'-diglucoside and quercetin 4'-glucoside. In general, the levels of flavonols were, higher in yellow onions than in red onions, and garlic and leek contained a lower amount of flavonols than the other Allium species. Our results highlight how (1)H NMR together with HPLC-MS can be useful in the quantification and the identification of the most abundant metabolites, representing an efficient means to pinpoint important functional food ingredients from Allium species. PMID:25038704

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

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

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

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

    2014-01-03

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

  15. 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

  16. 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...

  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. Faster metabolite (1H transverse relaxation in the elder human brain.

    Małgorzata Marjańska

    Full Text Available (1H magnetic resonance spectroscopy (MRS is unique among imaging modalities because signals from several metabolites are measured during a single examination period. Each metabolite reflects a distinct intracellular process. Furthermore transverse (T2 relaxation times probe the viability of the cell microenvironment, e.g., the viscosity of the cellular fluids, the microscopic susceptibility distribution within the cells, and the iron content. In this study, T2s of brain metabolites were measured in the occipital lobe of eighteen young and fourteen elderly subjects at a field strength of 4 tesla. The T2s of N-acetylaspartate, total creatine, and total choline were 23%, 16% and 10% shorter in elderly than in young subjects. The findings of this study suggest that noninvasive detection of T2 provides useful biological information on changes in the cellular microenvironment that take place during aging.

  19. 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

  20. 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

  1. 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 ...

  2. 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...

  3. 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...

  4. 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)

  5. 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

  6. 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.

  7. 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)

  8. 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)

  9. 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)

  10. 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.

  11. 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

  12. {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.

  13. 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

  14. 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

  15. (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

  16. 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

  17. 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.

  18. 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.

  19. 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

  20. 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 ...

  1. 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

  2. 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.

  3. 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%

  4. 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.

  5. 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

  6. 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.

  7. 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 ...

  8. 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)

  9. {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.

  10. 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.

  11. 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.

  12. 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)

  13. 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.

  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. 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 ...

  16. 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...

  17. 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

  18. 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.

  19. 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

  20. 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.

  1. 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

  2. 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…

  3. 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.

  4. 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

    【目的】应用1H 谱核磁共振(1H NMR)技术筛选乳热奶牛血清内差异表现的小分子代谢物,从小分子水平和物质、能量代谢的角度探究奶牛发生乳热时其体内的代谢变化。【方法】选取年龄、胎次、体况和泌乳量相近的分娩当天的荷斯坦高产奶牛共32头,根据其血清中钙离子浓度及其有无临床症状分为两组。其中,24头奶牛为健康对照组(Group1,血钙浓度>2.5 mmol·L-1,无其他任何症状)和8头乳热组(Group2,血钙浓度 2.5 mmol·L-1, without any other symptoms) and 8 MF group (Group2, serum calcium concentrations <1.4mmol·L-1, with obvious clinical symptoms of MF). Blood at 10mL was collected from the jugular vein from each of the 32 cows before feeding and miking in the morning, placed in a centrifugal tube, centrifuged at 4℃, 1 500×g for 20min, and then the serum obtained by centrifugation was separately loaded in a 1.5 mL EP tube at -80℃ until the test. After thawing, 400 μL serums was taken from every EP tube, added 200 μL buffered salt solution, mixed well, and then 550 μL supernatant was extracted into 5 mm NMR tube after centrifugation to collect signals using the 500 MHz NMR spectrometer. Then MestReNova and Topspin softwares were applied on the Fourier transform of the signal, the correction of zero, the baseline and phase, removed water and urea peaks, and the integration of one-dimensional map for segmentation, and mapping information into a TXT file format to facilitate subsequent data analysis, and then all compounds were identified using the Chenomx software. Finally, the SIMCA-P software was used for the multivariate statistical analysis, including principal component analysis (PCA) and orthogonal signal correction-partial least squares-discriminant analysis (OSC-PLS-DA), combined with the P values obtained from one-way ANOVA of NMR data performed in SPSS software and Loading plot, eventually small molecule metabolites

  5. 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.

  6. 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.

  7. 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

  8. 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)

  9. 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

  10. 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.

  11. 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

  12. 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

  13. 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

  14. 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.

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

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

  16. 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.

  17. Quantitation of normal metabolite concentrations in six brain regions by in-vivo 1H-MR spectroscopy

    Minati, Ludovico; Aquino, Domenico; Bruzzone, Maria Grazia; Erbetta, Alessandra

    2010-01-01

    This study examined the concentrations of brain metabolites visible to in-vivo 1H-Magnetic Resonance Spectroscopy (1H-MRS) at 1.5 T in a sample of 28 normal subjects. Quantitation was attempted for inositol compounds, choline units, total creatine and N-acetyl moieties, using open-source software. Six brain regions were considered: frontal and parietal white matter, medial temporal lobe, thalamus, pons and cerebellum. Absolute concentrations were derived using tissue water as an internal refe...

  18. 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.

  19. 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.

  20. 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)

  1. 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

  2. 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.

  3. 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

  4. 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.

  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. 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

  7. 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

  8. 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.

  9. 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...

  10. 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.

  11. 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.

  12. 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

  13. Absolute nutrient concentration measurements in cell culture media: (1)H q-NMR spectra and data to compare the efficiency of pH-controlled protein precipitation versus CPMG or post-processing filtering approaches.

    Goldoni, Luca; Beringhelli, Tiziana; Rocchia, Walter; Realini, Natalia; Piomelli, Daniele

    2016-09-01

    The NMR spectra and data reported in this article refer to the research article titled "A simple and accurate protocol for absolute polar metabolite quantification in cell cultures using q-NMR" [1]. We provide the (1)H q-NMR spectra of cell culture media (DMEM) after removal of serum proteins, which show the different efficiency of various precipitating solvents, the solvent/DMEM ratios, and pH of the solution. We compare the data of the absolute nutrient concentrations, measured by PULCON external standard method, before and after precipitation of serum proteins and those obtained using CPMG (Carr-Purcell-Meiboom-Gill) sequence or applying post-processing filtering algorithms to remove, from the (1)H q-NMR spectra, the proteins signal contribution. For each of these approaches, the percent error in the absolute value of every measurement for all the nutrients is also plotted as accuracy assessment. PMID:27331118

  14. 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

  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. 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.

  17. 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.

  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. 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.

  20. 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

  1. 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.

  2. Off-resonance rotating frame spin-lattice NMR relaxation studies of phosphorus metabolite rotational diffusion in bovine lens homogenates

    The rotational diffusion behavior of phosphorus metabolites present in calf lens cortical and nuclear homogenates was investigated by the NMR technique of 31P off-resonance rotating frame spin-lattice relaxation as a means of assessing the occurrence and extent of phosphorus metabolite-lens protein interactions. 31P NMR spectra of calf lens homogenates were obtained at 10 and 18 degree C at 7.05 T. Effective rotational correlation times (τ0,eff) for the major phosphorus metabolites present in cortical and nuclear bovine calf lens homogenates were derived from nonlinear least-squares analysis of R vs ωe data with the assumption of isotropic reorientational motion. Intramolecular dipole-dipole (1H-31P, 31P-31P), chemical shift anisotropy (CSA), and solvent (water) translational intermolecular dipole-dipole (1H-31P) relaxation contributions were assumed in the analyses. A fast-exchange model between free and bound forms, was employed in the analysis of the metabolite R vs ωe curves to yield the fraction of free (unbound) metabolite (Θfree). The results of this study establish the occurrence of significant temperature-dependent (above and below the cold cataract phase transition temperature) binding of ATP (cortex) and PME (nucleus) and pi (nucleus) in calf lens

  3. 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…

  4. 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...

  5. 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

  6. 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.

  7. (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

  8. 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

  9. 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

  10. 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.

  11. 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.

  12. 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

  13. 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.

  14. 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.

  15. (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

  16. 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.

  17. Cp-MAS solid state NMR of secondary metabolites from northeastern Brazil plants

    Aiming to learn more about the 13 C NMR of secondary metabolites in the solid state, as well as to make use of the Cp-MAS probe available in the CENAUREMN (Northeastern Center for Application and Use od NMR) laboratory, an analysis has been performed on the the following six classes of secondary metabolites: diterpenes, coumarins, alkaloids, flavonoids and purines

  18. 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.

  19. 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

  20. 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.

  1. 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

  2. Purification and H-1 NMR spectroscopic characterization of phase II metabolites of tolfenamic acid

    Sidelmann, U. G.; Christiansen, E.; Krogh, L.;

    1997-01-01

    acid; the study shows the applicability of H-1 NMR for the identification of drug metabolites in biological fluids. In addition to NMR analysis, two metabolites were also identified by mass spectrometry (MS), The glucuronides of the following parent compounds, N-(2-methyl-3-chlorophenyl...... endogenous polar compounds that are present in the urine. The individual metabolites were purified by preparative high performance liquid chromatography (HPLC) and then identified using H-1 NMR, Both one- and two-dimensional NMR experiments were performed to identify the phase II metabolites of tolfenamic......), and N-(2-methyl-4-hydroxyphenyl)-anthranilic acid (11) were identified. The phase II metabolites (5-11) had not previously been identified in urine from humans administered tolfenamic acid. The phase I metabolites of the glucuronides 7, 8, 10, and 11 were identified here for the first time. An HPLC...

  3. (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

  4. 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

  5. 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

  6. 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.

  7. 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)

  8. 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.

  9. 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...

  10. 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.

  11. 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.)

  12. 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.)

  13. 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℃.

  14. 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

  15. 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.

  16. 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.

  17. 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...

  18. 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...

  19. 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

  20. 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

  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. 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)

  3. 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

  4. Influence of different TE on reliability of brain metabolites quantification in high field 1H MRS

    Rackayová, V.; Cudalbu, C.; Xin, L.; Kunz, N.; Starčuková, Jana; Starčuk jr., Zenon; Gruetter, R.

    Vol. 23. Berkeley: Society of Magnetic Resonance, 2015. s. 1945. [ISMRM. Annual Meeting and Exhibition /23./. 30.05.2015-05.06.2015, Toronto] Institutional support: RVO:68081731 Keywords : MRS * metabolites * quantitation * short TE * simulation Subject RIV: BH - Optics, Masers, Lasers

  5. 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

  6. 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

  7. 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

  8. 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.

  9. {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.

  10. Quantitation of normal metabolite concentrations in six brain regions by in-vivo 1 H-MR spectroscopy

    Minati Ludovico

    2010-01-01

    Full Text Available This study examined the concentrations of brain metabolites visible to in-vivo 1 H-Magnetic Resonance Spectroscopy ( 1 H-MRS at 1.5 T in a sample of 28 normal subjects. Quantitation was attempted for inositol compounds, choline units, total creatine and N-acetyl moieties, using open-source software. Six brain regions were considered: frontal and parietal white matter, medial temporal lobe, thalamus, pons and cerebellum. Absolute concentrations were derived using tissue water as an internal reference and using an external reference; metabolite signal intensity ratios with respect to creatine were also calculated. The inter-individual variability was smaller for absolute concentrations (internal reference as compared to that for signal intensity ratios. Significant regional variability in concentration was found for all metabolites, indicating that separate normative values are needed for different brain regions. The values obtained in this study can be used as reference in future studies, provided the same methodology is followed; it is confirmed that despite unsuccessful attempts in the past, smaller coefficients of variation can indeed be obtained through absolute quantification.

  11. Quantitation of normal metabolite concentrations in six brain regions by in-vivo 1H-MR spectroscopy

    Minati, Ludovico; Aquino, Domenico; Bruzzone, Maria Grazia; Erbetta, Alessandra

    2010-01-01

    This study examined the concentrations of brain metabolites visible to in-vivo 1H-Magnetic Resonance Spectroscopy (1H-MRS) at 1.5 T in a sample of 28 normal subjects. Quantitation was attempted for inositol compounds, choline units, total creatine and N-acetyl moieties, using open-source software. Six brain regions were considered: frontal and parietal white matter, medial temporal lobe, thalamus, pons and cerebellum. Absolute concentrations were derived using tissue water as an internal reference and using an external reference; metabolite signal intensity ratios with respect to creatine were also calculated. The inter-individual variability was smaller for absolute concentrations (internal reference) as compared to that for signal intensity ratios. Significant regional variability in concentration was found for all metabolites, indicating that separate normative values are needed for different brain regions. The values obtained in this study can be used as reference in future studies, provided the same methodology is followed; it is confirmed that despite unsuccessful attempts in the past, smaller coefficients of variation can indeed be obtained through absolute quantification. PMID:20927223

  12. 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

  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. 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

  15. 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)

  16. 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)

  17. 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

  18. 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.

  19. 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.

  20. 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.

  1. A guide to the identification of metabolites in NMR-based metabonomics/metabolomics experiments

    Everett, Jeremy R.; Dona, Anthony; Kyriakides, Michael; Scott, Flora; Shephard, Elizabeth; Varshavi, Dorsa; Veselkov, Kirill

    2016-01-01

    Metabonomics/metabolomics is an important science for the understanding of biological systems and the prediction of their behaviour, through the profiling of metabolites. Two technologies are routinely used in order to analyse metabolite profiles in biological fluids: nuclear magnetic resonance (NMR) spectroscopy and mass spectrometry (MS), the latter typically with hyphenation to a chromatography system such as liquid chromatography (LC), in a configuration known as LC–MS. With both NMR and ...

  2. (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

  3. 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

  4. {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.

  5. 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

  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. 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

  8. 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%.

  9. 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

  10. 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.