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Tomohiro Kimura, Atsuko Kimura, Mindong Ren, Bob Berno, Yang Xu, Michael Schlame, Richard M Epand
Tafazzin is the mitochondrial enzyme that catalyzes transacylation between a phospholipid and a lysophospholipid in remodeling. Mutations in tafazzin cause Barth syndrome, a potentially life-threatening disease with the major symptom of cardiomyopathy. In the tafazzin-deficient heart, cardiolipin (CL) acyl chains become abnormally heterogeneous unlike those in the normal heart with a single dominant linoleoyl species; tetralinoleoyl CL. In addition, the amount of CL decreases and monolysocardiolipin (MLCL) accumulates...
March 20, 2018: Biochemistry
Gaganpreet Kaur, Amanpreet Singh, Ajnesh Singh, Navneet Kaur, Narinder Singh
The unregulated use of organophosphates (OPs) as pesticides and toxic chemical warfare agents demands their continuous monitoring from a human health perspective. This study describes a fluorescence turn-on sensing assay for the selective quantification of OPs in aqueous medium. Metal complexes of two different Biginelli derivatives were processed in water through a reprecipitation technique. The engineered self-assembly of the pyridyl-2-cobalt complex (L1·Co(II)) was employed to selectively detect malathion while the pyridyl-4-cobalt complex (L2·Co(II)) could estimate azamethiphos fluorimetrically up to a detection limit of 9...
March 16, 2018: Dalton Transactions: An International Journal of Inorganic Chemistry
Anne Harrison-Marchand, Jie Guang, Romain Duwald, Jacques Maddaluno, Hassan Oulyadi, Sami Lakhdar, Annie-Claude Gaumont
The synthesis and identification of unprecedented gem-dianionic phosphorus compounds, i.e. gem-dilithium phosphido-boranes Li2[RP*BH3], with R = Ph or Cy, are reported in THF solution. Those are obtained by double deprotonation of the corresponding primary phosphine-borane precursors RPH2*BH3. Their in-depth structural study, based on multinuclear (1H, 6Li, 7Li, 11B, 13C, 31P) mono- and bi-dimensional NMR analyses, indicates a strong influence of the phosphorus substituent on the structure of the gem-dianionic phosphorus structure: while a monomeric arrangement is obtained when R = phenyl, a cyclic oligomer is observed for R = cyclohexyl...
March 13, 2018: Chemistry: a European Journal
Kyeong-Bae Seo, In-Hwan Lee, Jaeho Lee, Inho Choi, Tae-Lim Choi
Herein, we report a highly efficient Suzuki-Miyaura catalyst-transfer polycondensation (SCTP) of 3-alkylthiophenes using bench-stable but highly active Buchwald dialkylbiarylphospine Pd G3 precatalysts and N-methylimidodiacetic (MIDA)-boronate monomers. Initially, the feasibility of the catalyst-transfer process was examined by screening various dialkylbiarylphospine-Pd(0) species. After optimizing a small molecule model reaction, we identified both RuPhos and SPhos Pd G3 precatalysts as excellent catalyst systems for this purpose...
March 9, 2018: Journal of the American Chemical Society
Maria Zakharova, Nima Masoumifard, Yimu Hu, Jongho Han, Freddy Kleitz, Frédéric-Georges Fontaine
Conventional amines and phosphines, such as diethylenetriamine, diphenylpropylphosphine, triethylamine, and tetramethylpyperidine, were grafted or impregnated on the surface of metalated SBA-15 materials, such as Ti-, Al-, Zr-SBA-15, to generate air-stable solid-supported Lewis acid-base pairs. The Lewis acidity of the metalated materials before and after the introduction of Lewis bases was verified by means of pyridine adsorption-FTIR technique. Detailed characterization of the materials was achieved by solid state 13C, 31P and 1H MAS NMR spectroscopy, low temperature N2 physisorption, XPS and EDX mapping analyses...
March 9, 2018: ACS Applied Materials & Interfaces
Arobendo Mondal, Martin Kaupp
A novel protocol to compute and analyze NMR chemical shifts for extended paramagnetic solids, accounting comprehensively for Fermi-contact (FC), pseudo-contact (PC), and orbital shifts, is reported and applied to the important lithium ion battery cathode materials LiFePO4 and LiCoPO4. Using an EPR-parameter-based ansatz, the approach combines periodic (hybrid) DFT computation of hyperfine and orbital-shielding tensors with an incremental cluster model for g- and zero-field-splitting (ZFS) D-tensors. The cluster model allows the use of advanced multi-reference wave-function methods (such as CASSCF or NEVPT2)...
March 7, 2018: Journal of Physical Chemistry Letters
Claudio Gioia, Giada Lo Re, Martin Lawoko, Lars A Berglund
Here we report the synthesis of thermosetting resins from low molar mass Kraft lignin fractions of high functionality, re-fined by solvent extraction. Such fractions were fully characterized by 31P-NMR, 2D-HSQC NMR, SEC and DSC in order to obtain a detailed description of the structures. Reactive oxirane moieties were introduced on the lignin backbone under mild reaction conditions and quantified by simple 1H-NMR analysis. The modified fractions were chemically cross-linked with a flexible polyether diamine (Mn≈2000), in order to obtain epoxy thermosets...
March 2, 2018: Journal of the American Chemical Society
Hyun Ho Lee, Dongsik Nam, Choon-Ki Kim, Koeun Kim, Yongwon Lee, Young Jun Ahn, Jae Bin Lee, Ja Hun Kwak, Wonyoung Choe, Nam-Soon Choi, Sung You Hong
Here we report the first electrochemical assessment of organophosphonate-based compound as a safe electrode material for lithium-ion batteries, which highlights reversible redox activity and inherent flame retarding property. Dinickel 1,4-benzenediphosphonate delivers a high reversible capacity of 585 mA h g-1 with stable cycle performance. It expands the scope of organic batteries, which have been mainly dominated by organic carbonyl family to date. The redox chemistry is elucidated by X-ray absorption spectroscopy and solid-state 31P NMR investigations...
March 2, 2018: ACS Applied Materials & Interfaces
Erik F Kot, Sergey Alexandrovich Goncharuk, Alexander Sergeevich Arseniev, Konstantin S Mineev
Isotropic phospholipid bicelles are one of the most prospective membrane mimetics for the structural studies of membrane proteins in solution. Recent works provided an almost full set of data regarding the properties of isotropic bicelles, however, one major aspect of their behavior is still under consideration: the possible mixing between the lipid and detergent in the bilayer area. This problem may be resolved by studying the lipid phase transitions in bicelle particles. In the present work, we investigate two effects - phase transitions of bilayer lipids and temperature-induced growth of isotropic bicelles using the NMR spectroscopy...
February 27, 2018: Langmuir: the ACS Journal of Surfaces and Colloids
Meghan M Verstraete, Cecilia Perez-Borrajero, Kirstin L Brown, David E Heinrichs, Michael E P Murphy
Staphyloferrin B (SB) is an iron-chelating siderophore produced by Staphylococcus aureus in invasive infections. Proteins for SB biosynthesis and export are encoded by the sbnABCDEFGHI gene cluster, in which SbnI, a member of the ParB/Srx superfamily, acts as a heme-dependent transcriptional regulator of the sbn locus. However, no structural or functional information about SbnI is available. Here, a crystal structure of SbnI revealed striking structural similarity to an ADP-dependent free serine kinase, SerK, from the archaea Thermococcus kodakarensis We found that features of the active sites are conserved, and biochemical assays, and 31P NMR and HPLC analyses indicated that SbnI is also a free serine kinase but uses ATP rather than ADP as phosphate donor to generate the SB precursor O-phospho-L-serine (OPS)...
February 26, 2018: Journal of Biological Chemistry
Loes A M Leenen, Ben F M Wijnen, Alfons G H Kessels, HoiYau Chan, Reina J A de Kinderen, Silvia M A A Evers, Caroline M van Heugten, Marian H J M Majoie
BACKGROUND: The objective of the ZMILE study was to compare the effectiveness of a multicomponent self-management intervention (MCI) with care as usual (CAU) in adult patients with epilepsy (PWE) over a six-month period. METHODS: Participants (PWE & relative) were randomized into intervention or CAU groups. Self-report questionnaires were used to measure disease-specific self-efficacy as the primary outcome measure and general self-efficacy, adherence, seizure severity, emotional functioning, quality of life, proactive coping, and side-effects of antiepileptic drugs (AED) as secondary outcome measures...
February 12, 2018: Epilepsy & Behavior: E&B
V V Balasubramanian, B M Devassay, S B Halligudi, R Deepika, S B Umbarakar, A Vinu
We demonstrate a highly active and reusable heterogeneous catalyst system, tungstophosphoric acid (TPA) supported on zirconia (ZrO2), for the cyclohexylation of resorcinol by cyclohexanol to produce value added chemicals such as 2-cyclohexyl resorcinol, 4-cyclohexyl resorcinol and 3-Hydroxy cyclohexyl phenyl ether under liquid phase reaction condition. TPA/ZrO2 catalysts prepared with different TPA loadings (5-30 wt.%) by wet impregnation method and calcined in the temperature range of 650-850 °C were characterized by Nitrogen sorption analysis, XRD, FTIR, DTG and DTA, and 31P MAS NMR spectroscopy...
April 1, 2018: Journal of Nanoscience and Nanotechnology
Chuhan Cheng, Cheng Liu, Bing Han, Zhijun Sun, Yutong Wang, Zhenshuai Li, Hong Mo, Jun Zhang
In this study, we report silver nanoparticles (Ag NPs) modified with sodium triphosphate (STTP) (Ag-STPP NPs) prepared by a simple surface modification and chemical reduction method. It was confirmed by 31P NMR spectroscopy that STPP was successfully introduced to the surface of Ag NPs. It was revealed by conductivity change measurements, bacterial growth kinetics and antibacterial efficiency tests that Ag-STPP NPs still retained the strong antibacterial ability. It was demonstrated by hemolysis assays, red blood cell morphology measurements, plasma recalcification time and in vitro clotting times that Ag-STPP NPs had improved hemocompatibility...
June 1, 2018: Journal of Nanoscience and Nanotechnology
Edjane R Dos Santos, Angelica E Graminha, Mario S Schultz, Isabel Correia, Heloisa S Selistre-de-Araújo, Rodrigo S Corrêa, Javier Ellena, Elisângela de Paula S Lacerda, João Costa Pessoa, Alzir A Batista
Thirteen new ruthenium amino acid complexes were synthesized and characterized. They were obtained by the reaction of α-amino acids (AA) with [RuCl2(P-P)(N-N)], where P-P=1,4-bis(diphenylphosphino)butane (dppb) or 1,3-bis(diphenylphosphino)propane (dppp) and N-N=4,4'-dimethyl-2,2'-bipyridine (4'-Mebipy), 5,5'-dimethyl-2,2'-bipyridine (5'-Mebipy) or 4,4'-Methoxy-2-2'-bipyridine (4'-MeObipy). This afforded a family of complexes formulated as [Ru(AA-H)(P-P)(N-N)]PF6, where AA=glycine (Gly), L-alanine (Ala), L-valine (Val), L-tyrosine (Tyr), L-tryptophan (Trp), L-histidine (His) and L-methionine (Met)...
December 23, 2017: Journal of Inorganic Biochemistry
Soumya S Roy, Kate Appleby, Elizabeth Fear, Simon B Duckett
Signal Amplification by Reversible Exchange (SABRE) is used to switch on the latent singlet spin order of para-hydrogen (p-H2) so that it can hyperpolarize a substrate (sub = nicotinamide, nicotinate, niacin, pyrimidine and pyrazine). The substrate then reacts reversibly with [Pt(OTf)2(bis-diphenylphosphinopropane)] by displacing OTf- to form [Pt(OTf)(sub)(bis-diphenylphosphinopropane)]OTf. The 31P NMR signals of these metal complexes prove to be enhanced when the substrate possesses an accessible singlet state or long-lived Zeeman polarization...
February 12, 2018: Journal of Physical Chemistry Letters
Danushika C Manatunga, Rohini M de Silva, K M Nalin de Silva, Nuwan de Silva, E V A Premalal
This study was focused on the preparation of metal and polymer-mediated porous crystalline hydroxyapatite (HAp) nanocomposites for environmental applications. Four different nano HAp systems were synthesized, namely, microwave irradiated HAp (M1), Zn doped HAp (M2), Mg-doped HAp (M3) and sodium alginate incorporated HAp (M4), and characterized using X-ray diffraction (XRD), Fourier transform infra-red spectroscopy, scanning electron microscopy, transmission electron microscopy, atomic force microscopy, nuclear magnetic resonance (NMR), X-ray fluorescence, thermogravimetric analysis and Brunauer-Emmett-Teller (BET) analyses...
January 2018: Royal Society Open Science
Ivan Luptak, Aaron L Sverdlov, Marcello Panagia, Fuzhong Qin, David R Pimentel, Dominique Croteau, Deborah A Siwik, Joanne S Ingwall, Markus M Bachschmid, James A Balschi, Wilson S Colucci
Metabolic syndrome is a cluster of obesity-related metabolic abnormalities that lead to metabolic heart disease (MHD) with left ventricular pump dysfunction. Although MHD is thought to be associated with myocardial energetic deficiency, two key questions have not been answered. First, it is not known whether there is a sufficient energy deficit to contribute to pump dysfunction. Second, the basis for the energy deficit is not clear. To address these questions, mice were fed a high fat, high sucrose (HFHS) 'Western' diet to recapitulate the MHD phenotype...
January 31, 2018: Journal of Molecular and Cellular Cardiology
V V Mulloyarova, I S Giba, M A Kostin, G S Denisov, I G Shenderovich, P M Tolstoy
The hydrogen-bonded self-associates of dimethylphosphinic (1), diphenylphosphoric (2), phenylphosphinic (3), and bis(2,4,4-trimethylpentyl)phosphinic (4) acids have been studied by using liquid-state NMR down to 100 K in a low-freezing polar solvent, CDF3/CDClF2. The H/D isotope effects on 1H NMR chemical shifts caused by partial deuteration of hydroxyl groups unambiguously reveal the stoichiometry of the self-associates and the cooperativity of their hydrogen bonds. In all cases, cyclic trimers are the dominant form, while cyclic dimers are present as a minor form for 1 and 2...
January 31, 2018: Physical Chemistry Chemical Physics: PCCP
Alejandro Santos-Díaz, Sergei I Obruchkov, Rolf F Schulte, Michael D Noseworthy
OBJECT: To present and evaluate a fast phosphorus magnetic resonance spectroscopic imaging (MRSI) sequence using echo planar spectroscopic imaging with flyback readout gradient trajectories. MATERIALS AND METHODS: Waveforms were designed and implemented using a 3 Tesla MRI system. 31P spectra were acquired with 2 × 2 cm2 and 3 × 3 cm2 resolution over a 20- and 21-cm field of view and spectral bandwidths up to 1923 Hz. The sequence was first tested using a 20-cm-diameter phosphate phantom, and subsequent in vivo tests were performed on healthy human calf muscles and brains from five volunteers...
January 30, 2018: Magma
Michael W Swift, Chris G Van de Walle, Matthew P A Fisher
We investigate "Posner molecules", calcium phosphate clusters with chemical formula Ca9(PO4)6. Originally identified in hydroxyapatite, Posner molecules have also been observed as free-floating molecules in vitro. The formation and aggregation of Posner molecules have important implications for bone growth, and may also play a role in other biological processes such as the modulation of calcium and phosphate ion concentrations within the mitochondrial matrix. In this work, we use a first-principles computational methodology to study the structure of Posner molecules, their vibrational spectra, their interactions with other cations, and the process of pairwise bonding...
January 30, 2018: Physical Chemistry Chemical Physics: PCCP
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