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Magnetic Nuclear Resonance

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https://www.readbyqxmd.com/read/28335566/profiling-and-preparation-of-metabolites-from-pyragrel-in-human-urine-by-online-solid-phase-extraction-coupled-with-high-performance-liquid-chromatography-tandem-mass-spectrometry-followed-by-a-macroporous-resin-based-purification-approach
#1
Xin Zhao, Jingjing Jiang, Guang Yang, Jie Huang, Guoping Yang, Guangwei He, Zhaoxing Chu, Taijun Hang, Guorong Fan
Pyragrel, a new anticoagulant drug, is derived from the molecular combination of ligustrazine and ferulic acid. Pyragrel showed significant inhibitory activity against platelet aggregation induced by adenosine diphosphate (ADP), and had been approved for a phase I clinical trial by CFDA. To characterize the metabolites of Pyragrel in human urine after intravenous administration, a reliable online solid-phase extraction couple with high performance liquid chromatography tandem mass spectrometry (online SPE-HPLC-MS(n)) method was conceived and applied...
March 21, 2017: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
https://www.readbyqxmd.com/read/28335293/cholesterol-modified-amino-pullulan-nanoparticles-as-a-drug-carrier-comparative-study-of-cholesterol-modified-carboxyethyl-pullulan-and-pullulan-nanoparticles
#2
Xiaojun Tao, Yongchao Xie, Qiufang Zhang, Ximin Qiu, Liming Yuan, Yi Wen, Min Li, Xiaoping Yang, Ting Tao, Minghui Xie, Yanwei Lv, Qinyi Wang, Xing Feng
To search for nano-drug preparations with high efficiency in tumor treatment, we evaluated the drug-loading capacity and cell-uptake toxicity of three kinds of nanoparticles (NPs). Pullulan was grafted with ethylenediamine and hydrophobic groups to form hydrophobic cholesterol-modified amino-pullulan (CHAP) conjugates. Fourier transform infrared spectroscopy and nuclear magnetic resonance were used to identify the CHAP structure and calculate the degree of substitution of the cholesterol group. We compared three types of NPs with close cholesterol hydrophobic properties: CHAP, cholesterol-modified pullulan (CHP), and cholesterol-modified carboxylethylpullulan (CHCP), with the degree of substitution of cholesterol of 2...
September 8, 2016: Nanomaterials
https://www.readbyqxmd.com/read/28335246/quaternized-carboxymethyl-chitosan-based-silver-nanoparticles-hybrid-microwave-assisted-synthesis-characterization-and-antibacterial-activity
#3
Siqi Huang, Jing Wang, Yang Zhang, Zhiming Yu, Chusheng Qi
A facile, efficient, and eco-friendly approach for the preparation of uniform silver nanoparticles (Ag NPs) was developed. The synthesis was conducted in an aqueous medium exposed to microwave irradiation for 8 min, using laboratory-prepared, water-soluble quaternized carboxymethyl chitosan (QCMC) as a chemical reducer and stabilizer and silver nitrate as the silver source. The structure of the prepared QCMC was characterized using Fourier transform infrared (FT-IR) and ¹H nuclear magnetic resonance (NMR)...
June 17, 2016: Nanomaterials
https://www.readbyqxmd.com/read/28335215/rapamycin-loaded-solid-lipid-nanoparticles-as-a-new-tool-to-deliver-mtor-inhibitors-formulation-and-in-vitro-characterization
#4
Alice Polchi, Alessandro Magini, Jarosław Mazuryk, Brunella Tancini, Jacek Gapiński, Adam Patkowski, Stefano Giovagnoli, Carla Emiliani
Recently, the use of mammalian target of rapamycin (mTOR) inhibitors, in particular rapamycin (Rp), has been suggested to improve the treatment of neurodegenerative diseases. However, as Rp is a strong immunosuppressant, specific delivery to the brain has been postulated to avoid systemic exposure. In this work, we fabricated new Rp loaded solid lipid nanoparticles (Rp-SLN) stabilized with polysorbate 80 (PS80), comparing two different methods and lipids. The formulations were characterized by differential scanning calorimetry (DSC), nuclear magnetic resonance (NMR), wide angle X-ray scattering (WAXS), cryo-transmission electron microscopy (cryo-TEM), dynamic light scattering (DLS) and particle tracking...
May 9, 2016: Nanomaterials
https://www.readbyqxmd.com/read/28334993/the-mechanism-of-the-glycosylase-reaction-with-hogg1-base-excision-repair-enzyme-concerted-effect-of-lys249-and-asp268-during-excision-of-8-oxoguanine
#5
Jakub Šebera, Yoshikazu Hattori, Daichi Sato, David Reha, Radim Nencka, Takashi Kohno, Chojiro Kojima, Yoshiyuki Tanaka, Vladimír Sychrovský
The excision of 8-oxoguanine (oxoG) by the human 8-oxoguanine DNA glycosylase 1 (hOGG1) base-excision repair enzyme was studied by using the QM/MM (M06-2X/6-31G(d,p):OPLS2005) calculation method and nuclear magnetic resonance (NMR) spectroscopy. The calculated glycosylase reaction included excision of the oxoG base, formation of Lys249-ribose enzyme-substrate covalent adduct and formation of a Schiff base. The formation of a Schiff base with ΔG# = 17.7 kcal/mol was the rate-limiting step of the reaction. The excision of the oxoG base with ΔG# = 16...
March 6, 2017: Nucleic Acids Research
https://www.readbyqxmd.com/read/28334906/conformational-polymorphism-or-structural-invariance-in-dna-photoinduced-lesions-implications-for-repair-rates
#6
François Dehez, Hugo Gattuso, Emmanuelle Bignon, Christophe Morell, Elise Dumont, Antonio Monari
DNA photolesions constitute a particularly deleterious class of molecular defects responsible for the insurgence of a vast majority of skin malignant tumors. Dimerization of two adjacent thymines or cytosines mostly gives rise to cyclobutane pyrimidine dimers (CPD) and pyrimidine(6-4)pyrimidone 64-PP as the most common defects. We perform all-atom classical simulations, up to 2 μs, of CPD and 64-PP embedded in a 16-bp duplex, which reveal the constrasted behavior of the two lesions. In particular we evidence a very limited structural deformation induced by CPD while 64-PP is characterized by a complex structural polymorphism...
February 28, 2017: Nucleic Acids Research
https://www.readbyqxmd.com/read/28334744/stabilization-of-rna-hairpins-using-non-nucleotide-linkers-and-circularization
#7
Agnieszka Kiliszek, Leszek Blaszczyk, Ryszard Kierzek, Wojciech Rypniewski
An RNA hairpin is an essential structural element of RNA. Hairpins play crucial roles in gene expression and intermolecular recognition but are also involved in the pathogenesis of some congenital diseases. Structural studies of the hairpin motifs are impeded by their thermodynamic instability, as they tend to unfold to form duplexes, especially at high concentrations required for crystallography or nuclear magnetic resonance spectroscopy. We have elaborated techniques to stabilize the RNA hairpins by linking the free ends of the RNA strand at the base of the hairpin stem...
February 21, 2017: Nucleic Acids Research
https://www.readbyqxmd.com/read/28333097/effects-of-a-sativex-like-combination-of-phytocannabinoids-on-disease-progression-in-r6-2-mice-an-experimental-model-of-huntington-s-disease
#8
Sara Valdeolivas, Onintza Sagredo, Mercedes Delgado, Miguel A Pozo, Javier Fernández-Ruiz
Several cannabinoids afforded neuroprotection in experimental models of Huntington's disease (HD). We investigated whether a 1:1 combination of botanical extracts enriched in either ∆⁸-tetrahydrocannabinol (∆⁸-THC) or cannabidiol (CBD), which are the main constituents of the cannabis-based medicine Sativex(®), is beneficial in R6/2 mice (a transgenic model of HD), as it was previously shown to have positive effects in neurotoxin-based models of HD. We recorded the progression of neurological deficits and the extent of striatal deterioration, using behavioral, in vivo imaging, and biochemical methods in R6/2 mice and their corresponding wild-type mice...
March 23, 2017: International Journal of Molecular Sciences
https://www.readbyqxmd.com/read/28332354/cyclized-oligopeptide-targeting-lrp5-6-dkk1-interaction-reduces-the-growth-of-tumor-burden-in-a-multiple-myeloma-mouse-model
#9
Bo Mi Park, Eun Jin Kim, Hee Jin Nam, Dongdong Zhang, Chu Hyun Bae, Myeongmo Kang, Heeyoun Kim, Weontae Lee, Bjarne Bogen, Sung Kil Lim
PURPOSE: Dickkopf 1 (DKK1) has been extensively investigated in mouse models of multiple myeloma, which results in osteolytic bone lesions. Elevated DKK1 levels in bone marrow plasma and serum inhibit the differentiation of osteoblast precursors. Present pharmaceutical approaches to target bone lesions are limited to antiresorptive agents. In this study, we developed a cyclized oligopeptide against DKK1-low density lipoprotein receptor-related protein (LRP) 5/6 interaction and tested the effects of the oligopeptide on tumor burden...
May 2017: Yonsei Medical Journal
https://www.readbyqxmd.com/read/28331191/identification-of-a-novel-small-molecule-partial-agonist-for-the-cyclic-amp-sensor-epac1
#10
Euan Parnell, Stuart P McElroy, Jolanta Wiejak, Gemma L Baillie, Alison Porter, David R Adams, Holger Rehmann, Brian O Smith, Stephen J Yarwood
Screening of a carefully selected library of 5,195 small molecules identified 34 hit compounds that interact with the regulatory cyclic nucleotide-binding domain (CNB) of the cAMP sensor, EPAC1. Two of these hits (I942 and I178) were selected for their robust and reproducible inhibitory effects within the primary screening assay. Follow-up characterisation by ligand observed nuclear magnetic resonance (NMR) revealed direct interaction of I942 and I178 with EPAC1 and EPAC2-CNBs in vitro. Moreover, in vitro guanine nucleotide exchange factor (GEF) assays revealed that I942 and, to a lesser extent, I178 had partial agonist properties towards EPAC1, leading to activation of EPAC1, in the absence of cAMP, and inhibition of GEF activity in the presence of cAMP...
March 22, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28330842/monocrotaline-induces-endothelial-injury-and-pulmonary-hypertension-by-targeting-the-extracellular-calcium-sensing-receptor
#11
Rui Xiao, Yuan Su, Tian Feng, Mengxiang Sun, Bingxun Liu, Jiwei Zhang, Yankai Lu, Jiansha Li, Tao Wang, Liping Zhu, Qinghua Hu
BACKGROUND: Monocrotaline has been widely used to establish an animal model of pulmonary hypertension. The molecular target underlying monocrotaline-induced pulmonary artery endothelial injury and pulmonary hypertension remains unknown. The extracellular calcium-sensing receptor (CaSR) and particularly its extracellular domain hold the potential structural basis for monocrotaline to bind. This study aimed to reveal whether monocrotaline induces pulmonary hypertension by targeting the CaSR...
March 22, 2017: Journal of the American Heart Association
https://www.readbyqxmd.com/read/28330349/coherent-manipulation-of-non-thermal-spin-order-in-optical-nuclear-polarization-experiments
#12
Gerd Buntkowsky, Konstantin L Ivanov, Herbert Zimmermann, Hans-Martin Vieth
Time resolved measurements of Optical Nuclear Polarization (ONP) have been performed on hyperpolarized triplet states in molecular crystals created by light excitation. Transfer of the initial electron polarization to nuclear spins has been studied in the presence of radiofrequency excitation; the experiments have been performed with different pulse sequences using different doped molecular systems. The experimental results clearly demonstrate the dominant role of coherent mechanisms of spin order transfer, which manifest themselves in well pronounced oscillations...
March 21, 2017: Journal of Chemical Physics
https://www.readbyqxmd.com/read/28330096/characterization-of-pyocyanin-with-radical-scavenging-and-antibiofilm-properties-isolated-from-pseudomonas-aeruginosa-strain-btry1
#13
M Laxmi, Sarita G Bhat
A biomolecule namely pyocyanin was isolated from Pseudomonas aeruginosa (BTRY1). It was confirmed by UV-Vis spectrum with absorption maxima at 270 nm and was further characterized using Fourier transform infrared (FTIR) and nuclear magnetic resonance (NMR). Spectroscopy analyses showed the presence of relevant bonds in their respective structures. Although pyocyanin had antihemolytic, antioxidant and antibiofilm activities against food pathogens, it showed no observable cytotoxicity, and thus proposed for potential use in the preservation of food...
June 2016: 3 Biotech
https://www.readbyqxmd.com/read/28328211/the-water-solvent-effect-on-theoretical-evaluation-of-1h-nmr-chemical-shifts-the-o-methyl-inositol-isomer
#14
Helio F Dos Santos, Marcelo Chagas, Leonardo De Souza, Willian Rocha, Mauro V De Almeida, Cleber P A Anconi, Wagner Batista De Almeida
In this paper, density functional theory calculations of nuclear magnetic resonance (NMR) chemical shifts for L-quebrachitol isomer, previously studied in our group (Mag. Res. Chem. 50 (2012) 608-614) are reported aiming to investigate in more details the water solvent effect on the prediction of 1H NMR spectra. In order to include explicit water molecules, twenty water-L-quebrachitol configurations obtained from Monte Carlo simulation were selected to perform geometry optimizations using the effective fragment potential method encompassing 60 water molecules around the solute...
March 22, 2017: Journal of Physical Chemistry. A
https://www.readbyqxmd.com/read/28328068/separation-of-enilconazole-enantiomers-in-capillary-electrophoresis-with-cyclodextrin-type-chiral-selectors-and-investigation-of-structure-of-selector-selectand-complexes-by-using-nuclear-magnetic-resonance-spectroscopy
#15
Ann Gogolashvili, Elene Tatunashvili, Lali Chankvetadze, Tamas Sohajda, Julianna Szeman, Antonio Salgado, Bezhan Chankvetadze
In the present study the enantiomer migration order (EMO) of enilconazole in the presence of various cyclodextrins (CDs) was investigated by capillary electrophoresis (CE). Opposite EMO of enilconazole were observed when β-CD or the sulfated heptakis(2-O-methyl-3,6-di-O-sulfo)-β-CD (HMDS-β-CD) was used as the chiral selectors. Nuclear Magnetic Resonance (NMR) spectroscopy was used to study the mechanism of chiral recognition between enilconazole enantiomers and those two cyclodextrins. On the basis of rotating frame nuclear Overhauser (ROESY) experiments, the structure of an inclusion complex between enilconazole and β-CD was derived, in which (+)-enilconazole seemed to form a tighter complex than the (-)-enantiomer...
March 22, 2017: Electrophoresis
https://www.readbyqxmd.com/read/28327659/the-immunosuppressant-mycophenolic-acid-alters-nucleotide-and-lipid-metabolism-in-an-intestinal-cell-model
#16
Svenja Heischmann, Monika Dzieciatkowska, Kirk Hansen, Dieter Leibfritz, Uwe Christians
The study objective was to elucidate the molecular mechanisms underlying the negative effects of mycophenolic acid (MPA) on human intestinal cells. Effects of MPA exposure and guanosine supplementation on nucleotide concentrations in LS180 cells were assessed using liquid chromatography-mass spectrometry. Proteomics analysis was carried out using stable isotope labeling by amino acids in cell culture combined with gel-based liquid chromatography-mass spectrometry and lipidome analysis using (1)H nuclear magnetic resonance spectroscopy...
March 22, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28327516/an-extract-from-shrimp-processing-by-products-protects-sh-sy5y-cells-from-neurotoxicity-induced-by-a%C3%AE-25-35
#17
Yongping Zhang, Guangling Jiao, Cai Song, Shelly Gu, Richard E Brown, Junzeng Zhang, Pingcheng Zhang, Jacques Gagnon, Steven Locke, Roumiana Stefanova, Claude Pelletier, Yi Zhang, Hongyu Lu
Increased evidence suggests that marine unsaturated fatty acids (FAs) can protect neurons from amyloid-β (Aβ)-induced neurodegeneration. Nuclear magnetic resonance (NMR), high performance liquid chromatography (HPLC) and gas chromatography (GC) assays showed that the acetone extract 4-2A obtained from shrimp Pandalus borealis industry processing wastes contained 67.19% monounsaturated FAs and 16.84% polyunsaturated FAs. The present study evaluated the anti-oxidative and anti-inflammatory effects of 4-2A in Aβ25-35-insulted differentiated SH-SY5Y cells...
March 22, 2017: Marine Drugs
https://www.readbyqxmd.com/read/28326124/adverse-effects-of-hydroalcoholic-extracts-and-the-major-components-in-the-stems-of-impatiens-balsamina-l-on-caenorhabditis-elegans
#18
Hong-Fang Jiang, Zi-Heng Zhuang, Bei-Wei Hou, Bao-Jun Shi, Cheng-Jie Shu, Lei Chen, Guo-Xin Shi, Wei-Ming Zhang
Impatiens balsamina L. (Balsaminaceae), an annual herb found throughout China, has been extensively used in traditional Chinese medicine (TCM). However, our knowledge regarding the adverse effects of I. balsamina in vivo is very limited. In this present study, the nematode Caenorhabditis elegans model was employed to fully assess the adverse effects of hydroalcoholic (EtOH 55%) extracts of I. balsamina stems (HAEIBS) in vivo. After exposure to 10 mg/mL HAEIBS, the major organism-level endpoints of C. elegans of percent survival, frequency of head thrash and body bends, and reproduction had decreased by 24%, 30%, and 25%, respectively...
2017: Evidence-based Complementary and Alternative Medicine: ECAM
https://www.readbyqxmd.com/read/28325822/structural-basis-for-chemokine-recognition-by-a-g-protein-coupled-receptor-and-implications-for-receptor-activation
#19
Joshua J Ziarek, Andrew B Kleist, Nir London, Barak Raveh, Nicolas Montpas, Julien Bonneterre, Geneviève St-Onge, Crystal J DiCosmo-Ponticello, Chad A Koplinski, Ishan Roy, Bryan Stephens, Sylvia Thelen, Christopher T Veldkamp, Frederick D Coffman, Marion C Cohen, Michael B Dwinell, Marcus Thelen, Francis C Peterson, Nikolaus Heveker, Brian F Volkman
Chemokines orchestrate cell migration for development, immune surveillance, and disease by binding to cell surface heterotrimeric guanine nucleotide-binding protein (G protein)-coupled receptors (GPCRs). The array of interactions between the nearly 50 chemokines and their 20 GPCR targets generates an extensive signaling network to which promiscuity and biased agonism add further complexity. The receptor CXCR4 recognizes both monomeric and dimeric forms of the chemokine CXCL12, which is a distinct example of ligand bias in the chemokine family...
March 21, 2017: Science Signaling
https://www.readbyqxmd.com/read/28325339/toward-novel-antiparasitic-formulations-complexes-of-albendazole-desmotropes-and-%C3%AE-cyclodextrin
#20
Ana K Chattah, Laura Y Pfund, Ariana Zoppi, Marcela R Longhi, Claudia Garnero
Novel complexes of two different solid forms of Albendazol and β-cyclodextrin were investigated in an attempt to obtain promising candidates for the preparation of alternative matrices used in pharmaceutical oral formulations. The interaction between each form of Albendazol and β-cyclodextrin was studied in solution and solid state, in order to investigate their effect on the solubility and dissolution rate of Albendazol solid forms. The solid supramolecular systems were characterized using a variety of techniques including natural-abundance (13)C cross-polarization magic-angle-spinning nuclear magnetic resonance, powder X-ray diffraction, Fourier transform-infrared spectroscopy and scanning electron microscopy...
May 15, 2017: Carbohydrate Polymers
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