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Jasmine Viger-Gravel, Anna Schantz, Arthur C Pinon, Aaron J Rossini, Staffan Schantz, Lyndon Emsley
Here we show how dynamic nuclear polarization (DNP) nuclear magnetic resonance (NMR) spectroscopy experiments permit the atomic level structural characterization of loaded and empty lipid nanoparticles (LNPs). The LNPs used here were synthesized by microfluidic mixing technique and are composed of ionizable cationic lipid (DLin-MC3-DMA), a phospholipid (DSPC), cholesterol and PEG (DMPE-PEG 2000), as well as encapsulated cargoes which are either phosphorothioated-siRNA (50 or 100%) or mRNA. We show that LNPs form physically stable complexes with bioactive drug siRNA for a period of 94 days...
January 14, 2018: Journal of Physical Chemistry. B
Wissam Iali, Peter J Rayner, Simon B Duckett
Hyperpolarization turns weak nuclear magnetic resonance (NMR) and magnetic resonance imaging (MRI) responses into strong signals, so normally impractical measurements are possible. We use parahydrogen to rapidly hyperpolarize appropriate 1H, 13C, 15N, and 31P responses of analytes (such as NH3) and important amines (such as phenylethylamine), amides (such as acetamide, urea, and methacrylamide), alcohols spanning methanol through octanol and glucose, the sodium salts of carboxylic acids (such as acetic acid and pyruvic acid), sodium phosphate, disodium adenosine 5'-triphosphate, and sodium hydrogen carbonate...
January 2018: Science Advances
Thomas Friedrich Fässler, Felix Geitner, Christoph Wallach
The reaction of [(Ge9{Si(TMS)3}2PtBu2)]- with NHCMesCuCl yields [(Ge9{Si(TMS)3}2)(tBu2P)]Cu(NHCMes) (1), which is a new derivative of the recently reported monomeric zwitterionic tetrel cluster compounds [(Ge9{Si(TMS)3}2)(tBu2P)]M(NHCDipp) (M: Cu, Ag, Au). By contrast, the reaction of the same anion [(Ge9{Si(TMS)3}2PtBu2)]- with the more labile copper phosphine complex Cy3PCuCl leads to the formation of [Ge9{Si(TMS)3}2{(tBu)2PCu}2Ge9{Si(TMS)3}2] (2) which is a neutral dimeric twofold-bridged [Ge9] cluster compound, with the exo-bonded phosphine substituent being involved in the cluster bridging...
January 11, 2018: Chemistry: a European Journal
Honghao Cai, Wei-Gang Chuang, Xiaohong Cui, Ren-Hao Cheng, Kuohsun Chiu, Zhong Chen, Shangwu Ding
Phosphorus metabolism and circulation are essential bio-physicochemical processes during development of a plant and have been extensively studied and known to be affected by temperature, humidity, lighting, hormones etc. However, a quantitative description of how various phosphorous species evolve over time has not been reported. In this work, a combined 31P liquid and solid state NMR spectroscopic methodology is employed, supported by a new extraction scheme and data analysis method, to carry out a quantitative investigation of phosphorous circulation in germinating sesame seeds in dark and under illumination with and without adding a growth hormone...
January 10, 2018: Scientific Reports
Andrew Ritchhart, Brandi Cossairt
We have synthesized InP nanocrystals of an unprecedented crystal phase at low temperature (35 - 100 °C) by templated growth of InP magic-sized clusters. With the addition of stoichiometric equivalents of P(SiMe3)3 to the starting cluster, we demonstrate nanocrystal growth mediated through a partial dissolution and recrystallization pathway. This growth process was monitored using a combination of in situ UV-Vis and 31P NMR spectroscopy, revealing the intermediacy of smaller cluster species of higher symmetry...
January 5, 2018: Angewandte Chemie
Yuchi Liu, Yuning Gu, Xin Yu
Many human diseases are caused by an imbalance between energy production and demand. Magnetic resonance spectroscopy (MRS) and magnetic resonance imaging (MRI) provide the unique opportunity for in vivo assessment of several fundamental events in tissue metabolism without the use of ionizing radiation. Of particular interest, phosphate metabolites that are involved in ATP generation and utilization can be quantified noninvasively by phosphorous-31 (31P) MRS/MRI. Furthermore, 31P magnetization transfer (MT) techniques allow in vivo measurement of metabolic fluxes via creatine kinase (CK) and ATP synthase...
December 2017: Quantitative Imaging in Medicine and Surgery
Ernesto Rufino-Felipe, Miguel-Ángel Muñoz-Hernández, Virginia Montiel-Palma
A series of lithium complexes ([Ph₂P(o-C₆H₄-CH₂Li·TMEDA)] (1-Li), [PhP(o-C₆H₄-CH₃)(o-C₆H₄-CH₂Li·TMEDA)] (2-Li), [PhP(o-C₆H₄-CH₂Li·TMEDA)₂] (2-Li₂) and [P(o-C₆H₄-CH₂Li·TMEDA)₃] (3-Li₃)) was prepared from mono-, di- and tri-benzylphosphines and varying amounts of nBuLi and was characterized extensively by IR and ¹H, ⁷Li, 13C and 31P NMR spectroscopy. The molecular structures of complexes 1-Li and 2-Li were determined by single-crystal X-ray diffraction studies. The two complexes have monomeric structures in the solid state comprising seesaw lithium atoms...
December 30, 2017: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
Laura Ludovica Gramegna, Maria Pia Giannoccaro, David Neil Manners, Claudia Testa, Stefano Zanigni, Stefania Evangelisti, Claudio Bianchini, Federico Oppi, Roberto Poda, Patrizia Avoni, Raffaele Lodi, Rocco Liguori, Caterina Tonon
The pathophysiological mechanism linking the nucleotide expansion in the DMPK gene to the clinical manifestations of myotonic dystrophy type 1 (DM1) is still unclear. In vitro studies demonstrate DMPK involvement in the redox homeostasis of cells and the mitochondrial dysfunction in DM1, but in vivo investigations of oxidative metabolism in skeletal muscle have provided ambiguous results and have never been performed in the brain. Twenty-five DM1 patients (14M, 39 ± 11years) underwent brain proton MR spectroscopy (1H-MRS), and sixteen cases (9M, 40 ± 13 years old) also calf muscle phosphorus MRS (31P-MRS)...
November 14, 2017: Neuromuscular Disorders: NMD
Yutaka Inoue, Mitsue Hibino, Isamu Murata, Ikuo Kanamoto
PURPOSE: As trisodium L-ascorbyl 2-phosphate 6-palmitate (APPS), an ascorbic acid derivative, is an amphiphilic substance, it forms micelles in aqueous solutions. Micelles are used as drug carriers and can emulsify drugs that are poorly soluble in water, such as nadifloxacin (NDFX). The purpose of this study was to prepare nanocarriers using APPS to carry NDFX into Yucatan micropig skin. METHODS: After synthesis of the NDFX nanoparticles by using the hydration method, physical evaluations were carried out that included assessments of particle size and zeta potential, encapsulation efficiency, particle structure by transmission electron microscopy, 31P-NMR spectra, and particle stability...
December 28, 2017: Pharmaceutical Research
Alla Malinenko, Alban Jonchere, Luc Girard, Sandra Parrès-Maynadié, Olivier Diat, Pierre Bauduin
Owing to their multiple charges and their nanometric size polyoxometalates (POMs) are at the frontier between ions and charged colloids. We investigated here the effect of POM-POM electrostatics repulsions on their self-diffusion in water by varying POM and supporting salt concentrations. The self-diffusion coefficients of two Keggin's POMs: silicotungstate (SiW4-) and phosphotungstate (PW3-) were determined by dynamic light scattering (DLS) and DOSY 1H/31P NMR whereas POM-POM electrostatic repulsions were investigated by the determination of the static structure factors using small angle X-ray scattering (SAXS)...
December 26, 2017: Langmuir: the ACS Journal of Surfaces and Colloids
Yan Xia, Tian-Ying Chen, Jia-Long Wen, Yi-Li Zhao, Jian Qiu, Run-Cang Sun
A large number of archaeological wooden building poles have been excavated from the Hai Menkou site (Yunnan province, China). Lignin can be transformed and altered accompanied with significant loss of carbohydrates during this process. Elucidation of chemical and structural transformations of lignin is of primary importance for understanding both the nature of degradation processes and the structure of waterlogged archaeological wood, and crucial for developing proper consolidation technology and restoring artifacts of historical and cultural value...
December 20, 2017: International Journal of Biological Macromolecules
Martin Pendola, John Spencer Evans
In the mollusk shell nacre layer there exist hydrogelator proteomes that play important roles in the formation of the mineral phase. Two of these proteomes, the intracrystalline and the framework, reside in the interior and exterior, respectively, of the nacre tablets. To date there is no clear evidence of what distinguishes an intracrystalline protein from a framework protein regarding the nucleation process. Using Eu(III), phosphate anions, and recombinant versions of the intracrystalline protein, AP7 and the framework protein, n16...
December 20, 2017: Journal of Physical Chemistry. B
Valentina Citro, Chiara Cimmaruta, Ludovica Liguori, Gaetano Viscido, Maria Vittoria Cubellis, Giuseppina Andreotti
The most frequent disorder of glycosylation, PMM2-CDG, is caused by a deficiency of phosphomannomutase activity. In humans two paralogous enzymes exist, both of them require mannose 1,6-bis-phosphate or glucose 1,6-bis-phosphate as activators, but only phospho-mannomutase1 hydrolyzes bis-phosphate hexoses. Mutations in the gene encoding phosphomannomutase2 are responsible for PMM2-CDG. Although not directly causative of the disease, the role of the paralogous enzyme in the disease should be clarified. Phosphomannomutase1 could have a beneficial effect, contributing to mannose 6-phosphate isomerization, or a detrimental effect, hydrolyzing the bis-phosphate hexose activator...
2017: PloS One
Sarah Keller, Timothy N Camenzind, Johannes Abraham, Alessandro Prescimone, Daniel Häussinger, Edwin C Constable, Catherine E Housecroft
We present a study of the self-assembling behaviour in solution of Ag[PF6] with one equivalent of an N^N ligand (N^N = 6,6'-dimethyl-2,2'-bipyridine (6,6'-Me2bpy) or 2,2':6',2''-terpyridine (tpy)), together with either 0.5 or one equivalent of the bridging ligand bis(diphenylphosphino)ethyne (dppa). Each product contains a dinuclear cation, with one or two dppa ligands bridging the two Ag+ centres; 6,6'-Me2bpy and tpy, respectively, act as chelating ligands. The compounds have been analysed in solution using NMR spectroscopic methods (1H, 1H{31P}, COSY, NOESY, 13C, HMQC and HMBC), including room and low temperature measurements...
December 20, 2017: Dalton Transactions: An International Journal of Inorganic Chemistry
Sauvik Chatterjee, Piyali Bhanja, Luna Paul, Mahammad Ali, Asim Bhaumik
Heterogeneous catalysts play a key role in addressing the economic and environmental issues of the chemical industry due to their several advantages, like ease of product separation, work-up and high recycling efficiency. Herein, we report the synthesis of a robust manganese(iv)-containing aluminophosphate material (MnAPO-5), with an AFI framework topology. This material has been characterized thoroughly by powder XRD, XPS, UHR TEM, FE SEM, 31P CP MAS NMR, atomic absorption spectroscopy, UV-visible spectroscopy and TGA...
December 15, 2017: Dalton Transactions: An International Journal of Inorganic Chemistry
Julia M Stauber, Shiyu Zhang, Nataliya Gvozdik, Yanfeng Jiang, Laura Avena, Keith J Stevenson, Christopher C Cummins
An electrochemical cell consisting of cobalt ([CoII/III(P3O9)2]4-/3-) and vanadium ([VIII/II(P3O9)2]3-/4-) bistrimetaphosphate complexes as catholyte and anolyte species, respectively, was constructed with a cell voltage of 2.4 V and Coulombic efficiencies exceeding 90% for up to 100 total cycles. The [Co(P3O9)2]4- (1) and [V(P3O9)2]3- (2) complexes have favorable properties for flow-battery applications that include reversible redox chemistry, high stability toward electrochemical cycling, and high solubility in MeCN (1...
December 12, 2017: Journal of the American Chemical Society
Chen Hsu, Bo-Yuan Wu, Yu-Chuan Chang, Chi-Fon Chang, Tai-Ying Chiou, Nan-Wei Su
Soy isoflavones, daidzein (DAI) and genistein (GEN), have beneficial effects on human health. However, their oral bioavailability is hampered by low aqueous solubility. Our previous study revealed two water-soluble phosphorylated isoflavones conjugates of isoflavones, daidzein 7-O-phosphate and genistein 7-O-phosphate, generated by biotransformation of Bacillus subtilis BCRC80517 cultivated with isoflavones. In this study, two novel derivatives of isoflavones, daidzein 4'-O-phosphate and genistein 4'-O-phosphate, were identified by HPLC-ESI-MS/MS and 1H, 13C and 31P NMR and the biotransformation road map was proposed...
December 12, 2017: Journal of Agricultural and Food Chemistry
Adrianus J Bakermans, Jason N Bazil, Aart J Nederveen, Gustav J Strijkers, S Matthijs Boekholdt, Daniel A Beard, Jeroen A L Jeneson
Phosphorus-31 magnetic resonance spectroscopy (31P-MRS) is a unique non-invasive imaging modality for probing in vivo high-energy phosphate metabolism in the human heart. We investigated whether current 31P-MRS methodology would allow for clinical applications to detect exercise-induced changes in (patho-)physiological myocardial energy metabolism. Hereto, measurement variability and repeatability of three commonly used localized 31P-MRS methods [3D image-selected in vivo spectroscopy (ISIS) and 1D ISIS with 1D chemical shift imaging (CSI) oriented either perpendicular or parallel to the surface coil] to quantify the myocardial phosphocreatine (PCr) to adenosine triphosphate (ATP) ratio in healthy humans (n = 8) at rest were determined on a clinical 3 Tesla MR system...
2017: Frontiers in Physiology
Marie-Claude Gagnon, Erik Strandberg, Anne S Ulrich, Jean-François Paquin, Michèle Auger
Solid-state 19F NMR spectroscopy is a method of choice to study the interactions between lipid membranes and other molecules such as peptides, proteins or drugs. Numerous fluorine-labeled NMR probes have been developed over the last few years, especially fluorine-labeled peptides. In order to develop a new kind of NMR reporter molecule and a complementary approach to fluorine-labeling of peptides, we synthesized six monofluorinated derivatives of the lipid dimyristoylphosphatidylcholine (F-DMPC), with the fluorine atom located along the acyl chain linked to the central glycerol position...
December 6, 2017: Biochimica et Biophysica Acta
Michèle C Erat, Emina Besic, Michael Oberhuber, Silke Johannsen, Roland K O Sigel
Group II introns are large self-splicing ribozymes that require high amounts of monovalent and divalent metal ions for folding and catalysis under in vitro conditions. Domain 6 of these ribozymes contains a highly conserved adenosine whose 2'-OH acts as a nucleophile during self-cleavage via the branching pathway. We have previously suggested a divalent metal ion that binds to the major groove at the GU wobble pair above the branch-A in a minimal, but active branch domain construct (D6-27) from the yeast mitochondrial intron Sc...
December 7, 2017: Journal of Biological Inorganic Chemistry: JBIC
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