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https://www.readbyqxmd.com/read/28448888/isolation-identification-and-characterization-of-potential-impurities-of-anidulafungin
#1
Lanning Zhao, Qilong Wang, Yi Bie, Xiaoxia Lu
Eight impurities ranging from 0.03 to 0.97% in anidulafungin bulk drug were detected by HPLC. Four impurities (Imp-I, Imp-II, Imp-III and Imp-VIII) among impurities were isolated from the self-prepared or marketed samples of anidulafungin bulk drug by means of preparative HPLC. A thorough study was undertaken to characterize these impurities and based on 1D ((1)H, (13)C, H-D, DEPT 90 and 135) and 2D (COSY, TOCSY, HSQC, HMBC) NMR and ESI-MS spectral data. Based on the characterization data, Imp-I was found to be known open-chain hydrolysis product formed during the synthesis and degradation...
April 17, 2017: Journal of Pharmaceutical and Biomedical Analysis
https://www.readbyqxmd.com/read/28448884/antiproliferative-hydroxy-fatty-acids-from-the-fodder-legume-stylosanthes-guianensis
#2
Marco Clericuzio, Bruno Burlando, Barbara Borghesi, Annalisa Salis, Gianluca Damonte, Stefania Ribulla, Laura Cornara
Stylosanthes guianensis is a fodder legume native from South America and widely grown worldwide. Dried plant material was purchased on the web and taxonomically identified by light and SEM microscopy, and morphological analysis of plants germinated from seeds. The plant was extracted with dichloromethane:2-propanol (9:1). Bioguided fractionation using calcein-AM cytotoxicity assay on HeLa and A431 tumor cells allowed to isolate a lipophilic fraction, endowed with strong cytotoxicity. By means of 1- and 2-D NMR, HPLC-MS, and HR-ESIMS it could be seen that the fraction was an inseparable mixture of complex lipids, mainly consisting of esterified 3-hydroxy fatty acids...
April 17, 2017: Journal of Pharmaceutical and Biomedical Analysis
https://www.readbyqxmd.com/read/28448877/synthesis-structure-and-cytotoxicity-of-a-series-of-dioxidomolybdenum-vi-complexes-featuring-salan-ligands
#3
Satabdi Roy, Monalisa Mohanty, Sagarika Pasayat, Sudarshana Majumder, Kulanthaivel Senthilguru, Indranil Banerjee, Martin Reichelt, Hans Reuter, Ekkehard Sinn, Rupam Dinda
Seven hexacoordinated cis-dioxidomolybdenum(VI) complexes [MoO2L(1-7)] (1-7) derived from various tetradentate diamino bis(phenolato) "salan" ligands, N,N'-dimethyl-N,N'-bis-(2-hydroxy-3-X-5-Y-6-Z-benzyl)-1,2-diaminoethane {(X=Br, Y=Me, Z=H (H2L(1)); X=Me, YCl, Z=H (H2L(2)); X=(i)Pr, Y=Cl, Z=Me (H2L(3))} and N,N'-bis-(2-hydroxy-3-X-5-Y-6-Z-benzyl)-1,2-diaminopropane {(X=Y=(t)Bu, Z=H (H2L(4)); X=Y=Me, Z=H (H2L(5)); X=(i)Pr, YCl, Z=Me (H2L(6)); X=Y=Br, Z=H (H2L(7))} containing O-N donor atoms, have been isolated and structurally characterized...
April 18, 2017: Journal of Inorganic Biochemistry
https://www.readbyqxmd.com/read/28448799/isolation-of-antioxidant-phenolics-from-schinopsis-brasiliensis-based-on-a-preliminary-lc-ms-profiling
#4
Clisiane Carla de Souza Santos, Milena Masullo, Antonietta Cerulli, Angela Mari, Charles Dos Santos Estevam, Cosimo Pizza, Sonia Piacente
The phenolic content of the ethanol extract of the stem bark of the Brazilian plant Schinopsis brasiliensis Engl. (Anacardiaceae) has been evaluated together with the antioxidant activity. The good antioxidant activity exhibited in the Trolox Equivalent Antioxidant Capacity (TEAC) assay (TEAC value = 3.04 mg/mL) encouraged us to investigate its constituents. An analytical approach based on LC-ESIMS(n) was applied to rapidly obtain a metabolite profile of the ethanol extract of the stem bark of S. brasiliensis...
April 24, 2017: Phytochemistry
https://www.readbyqxmd.com/read/28448441/characterization-of-compounds-with-tumor-cell-proliferation-inhibition-activity-from-mushroom-phellinus-baumii-mycelia-produced-by-solid-state-fermentation
#5
Henan Zhang, Qian Shao, Wenhan Wang, Jingsong Zhang, Zhong Zhang, Yanfang Liu, Yan Yang
The inhibition of tumor-cell proliferationbyan organicsolvent extract from the solid-state fermentation of Phellinus baumii mycelia inoculated in rice medium was investigated in vitro. The active compounds inhibiting tumor-cell proliferation were characterized. Results revealed that all (petroleum ether, chloroform, ethyl acetate, and butanol) fractions inhibited tumor-cell proliferation in a dose-dependent fashion. The ethyl acetate extract had the highest inhibitory effecton tumor-cell proliferation, and the butanol fraction had the lowest...
April 27, 2017: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
https://www.readbyqxmd.com/read/28448234/leveraging-clinical-imaging-archives-for-radiomics-reliability-of-automated-methods-for-brain-volume-measurement
#6
Viraj R Adduru, Andrew M Michael, Maria Helguera, Stefi A Baum, Gregory J Moore
Purpose To validate the use of thick-section clinically acquired magnetic resonance (MR) imaging data for estimating total brain volume (TBV), gray matter (GM) volume (GMV), and white matter (WM) volume (WMV) by using three widely used automated toolboxes: SPM ( www.fil.ion.ucl.ac.uk/spm/ ), FreeSurfer ( surfer.nmr.mgh.harvard.edu ), and FSL (FMRIB software library; Oxford Centre for Functional MR Imaging of the Brain, Oxford, England, https://fsl.fmrib.ox.ac.uk/fsl ). Materials and Methods MR images from a clinical archive were used and data were deidentified...
April 27, 2017: Radiology
https://www.readbyqxmd.com/read/28448144/a-maldiisotopic-approach-to-discover-natural-products-cryptomaldamide-a-hybrid-tripeptide-from-the-marine-cyanobacterium-moorea-producens
#7
Robin B Kinnel, Eduardo Esquenazi, Tiago Leao, Nathan Moss, Emily Mevers, Alban R Pereira, Emily A Monroe, Anton Korobeynikov, Thomas F Murray, David Sherman, Lena Gerwick, Pieter C Dorrestein, William H Gerwick
Genome sequencing of microorganisms has revealed a greatly increased capacity for natural products biosynthesis than was previously recognized from compound isolation efforts alone. Hence, new methods are needed for the discovery and description of this hidden secondary metabolite potential. Here we show that provision of heavy nitrogen (15)N-nitrate to marine cyanobacterial cultures followed by single-filament MALDI analysis over a period of days was highly effective in identifying a new natural product with an exceptionally high nitrogen content...
April 27, 2017: Journal of Natural Products
https://www.readbyqxmd.com/read/28448138/idp-specific-force-field-ff14idpsff-improves-the-conformer-sampling-of-intrinsically-disordered-proteins
#8
Dong Song, Ray Luo, Hai-Feng Chen
Intrinsically disordered proteins (IDPs) or intrinsically disordered regions have not fixed tertiary structure, but play key roles in signal regulation, molecule recognition, and drug target. However it is difficult to study the structure and function of IDPs by traditional experimental methods because of their diverse conformations. Limitations of current generic protein force fields and solvent models were reported in the previous simulations of IDPs. We have also explored to overcome these limitations by developing ff99IDPs and ff14IDPs force fields to correct the dihedral distribution for eight disordered promoting residues often observed in IDPs and found encouraging improvements...
April 27, 2017: Journal of Chemical Information and Modeling
https://www.readbyqxmd.com/read/28448136/cucurbitane-glucosides-from-the-crude-extract-of-siraitia-grosvenorii-with-moderate-effects-on-pgc-1%C3%AE-promoter-activity
#9
Biao Niu, Chang-Qiang Ke, Bo-Han Li, Yuanyuan Li, Yongji Yi, Yongwei Luo, Lin Shuai, Sheng Yao, Li-Gen Lin, Jia Li, Yang Ye
Seven new cucurbitane glucosides, 11-oxomogrosides III E and IV (1 and 2), 11-oxoisomogroside V (3), 7-oxomogrosides III E and IV (4 and 5), and mogrosides VI A and VI B (6 and 7), were separated from the crude extract of Siraitia grosvenorii. The new structures were defined by analysis of their (1)H and (13)C NMR, 2D NMR, and HRESIMS data. Especially, the band-selective constant time HSQC and band-selective constant time HMBC techniques were recuited to elucidate the structures of the complex glucoside moieties...
April 27, 2017: Journal of Natural Products
https://www.readbyqxmd.com/read/28448133/design-of-novel-exendin-based-dual-glucagon-like-peptide-1-glp-1-glucagon-receptor-agonists
#10
Andreas Evers, Torsten Haack, Martin Lorenz, Martin Bossart, Ralf Elvert, Bernd Henkel, Siegfried Stengelin, Michael Kurz, Maike Glien, Angela Dudda, Katrin Lorenz, Dieter Kadereit, Michael Wagner
Dual activation of the glucagon-like peptide 1 (GLP-1) and glucagon receptor has the potential to lead to a novel therapy principle for the treatment of diabesity. Here, we report a series of novel peptides with dual activity on these receptors that were discovered by rational design. Based on sequence analysis and structure-based design, structural elements of glucagon were engineered into the selective GLP-1 receptor agonist exendin-4, resulting in hybrid peptides with potent dual GLP-1/glucagon receptor activity...
April 27, 2017: Journal of Medicinal Chemistry
https://www.readbyqxmd.com/read/28447979/reconstitution-of-nucleosomes-with-differentially-isotope-labeled-sister-histones
#11
Stamatios Liokatis
Asymmetrically modified nucleosomes contain the two copies of a histone (sister histones) decorated with distinct sets of Post-translational Modifications (PTMs). They are newly identified species with unknown means of establishment and functional implications. Current analytical methods are inadequate to detect the copy-specific occurrence of PTMs on the nucleosomal sister histones. This protocol presents a biochemical method for the in vitro reconstitution of nucleosomes containing differentially isotope-labeled sister histones...
March 26, 2017: Journal of Visualized Experiments: JoVE
https://www.readbyqxmd.com/read/28447800/stable-dihydrogen-complexes-of-cobalt-i-suggest-an-inverse-trans-influence-of-lewis-acidic-group-13-metalloligands
#12
Matthew Vollmer, Jing Xie, Connie C Lu
A triad of d(10) cobalt dihydrogen complexes were synthesized by utilizing Lewis acidic group 13 metallolig-ands, M[N((o-C6H4)NCH2P(i)Pr2)3], where M = Al, Ga, and In. These complexes have formal Co(-I) oxidation states, representing the only coordination complexes in which dihydrogen is bound to a subvalent transition metal center. Single-crystal X-ray diffraction and NMR studies support the assignment of these complexes as non-classical dihydrogen adducts of Co(-I).
April 27, 2017: Journal of the American Chemical Society
https://www.readbyqxmd.com/read/28447786/a-3d-mas-nmr-experiment-utilizing-through-space-15n-15n-correlations
#13
Kevin J Donovan, Robert Silvers, Sara Linse, Robert G Griffin
We demonstrate a novel 3D NNC magic angle spinning (MAS) NMR experiment that generates 15N- 15N internuclear contacts in protein systems using an optimized 15N- 15N proton assisted recoupling (PAR) mixing period and a 13C dimension for improved resolution. The optimized PAR condition permits the acquisition of high signal-to-noise 3D data that enables backbone chemical shift assignments using a strategy that is complementary to current schemes. The spectra can also provide distance constraints. The utility of the experiment is demonstrated on an M0Ab1-42 fibril sample that yields high-quality data that is readily assigned and interpreted...
April 27, 2017: Journal of the American Chemical Society
https://www.readbyqxmd.com/read/28447699/determination-of-paramagnetic-concentrations-inside-a-diamagnetic-matrix-using-solid-state-nmr
#14
Sébastien Maron, Nadège Ollier, Thierry Gacoin, Géraldine Dantelle
The determination of very low doping levels in solid materials is an important issue for many applications. When considering paramagnetic dopants, the NMR relaxation technique appears to be much more accurate than classical techniques such as Vegard's law resulting from X-ray diffraction (XRD) measurements or chemical analysis that cannot provide information on appropriate dopant spatial distributions. In a recent report, the linear variation of 1/T1, i.e. the nuclear relaxation rate, as a function of Nd(3+) content has been used to determine doping levels with a good dispersion homogeneity in the monazite LaPO4 matrix down to 0...
April 27, 2017: Physical Chemistry Chemical Physics: PCCP
https://www.readbyqxmd.com/read/28447692/pillar-5-arene-based-1-rotaxane-high-yield-synthesis-characterization-and-application-in-knoevenagel-reaction
#15
Xu-Sheng Du, Chun-Yu Wang, Qiong Jia, Rong Deng, Hua-Sheng Tian, Hou-Yu Zhang, Kamel Meguellati, Ying-Wei Yang
We report a quantitative synthetic strategy of a [1]rotaxane from a representative pseudo[1]rotaxane. The structure of the [1]rotaxane was characterized by (1)H NMR, (13)C NMR, 2D NMR, mass spectroscopy, and melting point, and its optimized geometry in CHCl3 by theoretical calculation at the B3LYP/6-31G(D) level using the PCM model matched well with 2D NOESY. This [1]rotaxane proves to be a good catalyst for the Knoevenagel reaction in CHCl3, which follows second order kinetics.
April 27, 2017: Chemical Communications: Chem Comm
https://www.readbyqxmd.com/read/28447666/in-situ-polymerisation-of-isoeugenol-as-a-green-consolidation-method-for-waterlogged-archaeological-wood
#16
Emily McHale, Calin C Steindal, Hartmut Kutzke, Tore Benneche, Stephen E Harding
Waterlogged archaeological wood is often in need of consolidation prior to drying to prevent shrinkage and cracking of the object. There is a need for new greener materials (than for example polyethylene glycol) and methods for consolidation to be developed. The use of wood-based components could provide good interaction between the consolidant and the remaining wood structure and would also support a shift away from fossil fuel-based materials to those with more sustainable sources. Based on this, lignin-like structures have been investigated for their ability to consolidate waterlogged archaeological wood...
April 27, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28447469/two-pairs-of-rare-naturally-occurring-4-hydroxy-4-methyl-2-5-heptanedione-derivatives-from-the-red-alga-chondria-crassicaulis
#17
Lin Tong, Yi Zhang, Ai-Hong Liu, Li-Gong Yao, Yue-Wei Guo, Shui-Chun Mao, Bin Wang
Two pairs of rare naturally occurring racemic lipids, (±)-4,7-dihydroxy-4-methyl-2,5-heptanedione (1), and (±)-7-butoxy-4-hydroxy-4-methyl-2,5-heptanedione (2) were isolated from the red alga Chondria crassicaulis Harv. The structures of the racemic mixtures of 1 and 2 were elucidated by detailed spectroscopic techniques, including 1D and 2D NMR ((1)H and (13)C NMR, (1)H-(1)H COSY, HSQC, and HMBC) as well as mass spectrometry and optical rotation experiments, and by comparison with data for related known analogs...
April 27, 2017: Journal of Asian Natural Products Research
https://www.readbyqxmd.com/read/28447460/effects-of-histidine-supplementation-on-global-serum-and-urine-1h-nmr-based-metabolomics-and-serum-amino-acid-profiles-in-obese-women-from-a-randomized-controlled-study
#18
Shanshan Du, Shuhong Sun, Liyan Liu, Qiao Zhang, Fuchuan Guo, Chunlong Li, Rennan Feng, Changhao Sun
The aim of current study was to investigate the metabolic changes associated with histidine supplementation in serum and urine metabolic signatures and serum amino acid (AA) profiles. Serum and urine 1H NMR-based metabolomics and serum AAs profiles were employed in thirty two and thirty seven obese women with metabolic syndrome (MetS) intervened with placebo or histidine for 12 weeks. Multivariable statistical analysis were conducted to define characteristic metabolites. In serum 1H NMR metabolic profiles, increases in histidine, glutamine, aspartate, glycine, choline, and trimethylamine-N-oxide (TMAO) were observed, meanwhile, decreases in cholesterol, triglycerides, fatty acids and unsaturated lipids, acetone, and α/β-Glucose were exhibited after histidine supplement...
April 27, 2017: Journal of Proteome Research
https://www.readbyqxmd.com/read/28447449/molecular-simulations-of-mixed-lipid-bilayers-with-sphingomyelin-glycerophospholipids-and-cholesterol
#19
Indrani Bera, Jeffery B Klauda
The highly-diversified composition of lipid bilayers across living cells is crucial for many biological processes. Lipid bilayers mainly consist of phosphatidylcholines (PC), phosphatidylethanolamines (PE), sphingomyelin (SM) and cholesterol, with eukaryotic membranes containing high percentage of sphingomyelin and cholesterol. In this study, we have modeled bilayers with different concentration of PC, PE and SM to understand the changes in bilayer properties with varied SM concentrations. In addition, membrane models with 33% cholesterol have been simulated to understand the influence of cholesterol...
April 27, 2017: Journal of Physical Chemistry. B
https://www.readbyqxmd.com/read/28447334/-1-h-nmr-1-h-nmr-t2-edited-and-2d-nmr-in-bipolar-disorder-metabolic-profiling
#20
Sumit Sethi, Mariana Pedrini, Lucas B Rizzo, Maiara Zeni-Graiff, Caroline Dal Mas, Ana Cláudia Cassinelli, Mariane N Noto, Elson Asevedo, Quirino Cordeiro, João G M Pontes, Antonio J M Brasil, Acioly Lacerda, Mirian A F Hayashi, Ronei Poppi, Ljubica Tasic, Elisa Brietzke
BACKGROUND: The objective of this study was to identify molecular alterations in the human blood serum related to bipolar disorder, using nuclear magnetic resonance (NMR) spectroscopy and chemometrics. METHODS: Metabolomic profiling, employing (1)H-NMR, (1)H-NMR T2-edited, and 2D-NMR spectroscopy and chemometrics of human blood serum samples from patients with bipolar disorder (n = 26) compared with healthy volunteers (n = 50) was performed. RESULTS: The investigated groups presented distinct metabolic profiles, in which the main differential metabolites found in the serum sample of bipolar disorder patients compared with those from controls were lipids, lipid metabolism-related molecules (choline, myo-inositol), and some amino acids (N-acetyl-L-phenyl alanine, N-acetyl-L-aspartyl-L-glutamic acid, L-glutamine)...
December 2017: International Journal of Bipolar Disorders
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