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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/28334552/isolation-and-characterization-of-novel-degradation-products-of-doxofylline-using-hplc-ftir-lcms-and-nmr
#2
Ch Krishnam Raju, Avadhesh K Pandey, Gururaj S, Kaushik Ghosh, Arunima Pola, Sanath Kumar Goud P, Mrunal A Jaywant, Sameer G Navalgund
Forced degradation of Doxofylline (DFL) in different stress (base and peroxide) conditions gave rise to two potential unknown impurities. These unknown degradation products DFL DEG-I and DFL DEG-II were evaluated using a new-reverse-phase high performance liquid chromatography (HPLC), where it was eluted at 0.44 and 1.09 relative retention times to DFL peak. DFL DEG-I and DFL DEG-II were isolated using preparative HPLC from degradation mixtures. The structure of DFL DEG-I and DFL DEG-II were elucidated using high resolution MS, multi-dimensional NMR and FTIR spectroscopic techniques, and characterized...
March 1, 2017: Journal of Pharmaceutical and Biomedical Analysis
https://www.readbyqxmd.com/read/28333680/physical-and-chemical-stability-of-urapidil-in-0-9-sodium-chloride-in-elastomeric-infusion-pump
#3
Cristina Tomasello, Anna Leggieri, Franco Rabbia, Franco Veglio, Lorena Baietto, Chiara Fulcheri, Amedeo De Nicolò, Giovanni De Perri, Antonio D'Avolio
Urapidil is an antihypertensive agent, usually administered through intravenous bolus injection, slow-intravenous infusion, or continuous-drug infusion by perfusor. Since to date no evidences are available on drug stability in elastomeric pumps, patients have to be hospitalized. The purpose of this study was to validate an ultra-performance liquid chromatographic method to evaluate urapidil stability in an elastomeric infusion pump, in order to allow continuous infusion as home-care treatment. Analyses were conducted by diluting urapidil in an elastomeric pump...
July 2016: International Journal of Pharmaceutical Compounding
https://www.readbyqxmd.com/read/28333457/two-dimensional-offline-chromatographic-fractionation-for-the-characterization-of-humic-like-substances-in-atmospheric-aerosol-particles
#4
Tobias Spranger, Dominik van Pinxteren, Hartmut Herrmann
Organic carbon in atmospheric particles comprises a large fraction of chromatographically unresolved compounds, often referred to as humic-like substances (HULIS), which influence particle properties and impacts on climate, human health and ecosystems. To better understand its composition, a two-dimensional (2D) offline method combining size-exclusion (SEC) and reversed-phase liquid chromatography (RP-HPLC) using a new spiked gradient profile is presented. It separates HULIS into 55 fractions of different size and polarity, with estimated ranges of molecular weight and octanol/water partitioning coefficient (log P) from 160-900 g/mol and 0...
March 23, 2017: Environmental Science & Technology
https://www.readbyqxmd.com/read/28333237/new-paenibacillus-strain-produces-a-family-of-linear-and-cyclic-antimicrobial-lipopeptides-cyclization-is-not-essential-for-their-antimicrobial-activity
#5
En Huang, Xu Yang, Liwen Zhang, Sun Hee Moon, Ahmed E Yousef
A new bacterial isolate, Paenibacillus sp. OSY-N, showed potent antimicrobial activity against Gram-negative and Gram-positive bacteria. Antimicrobials produced by this strain were purified by reverse-phase high performance liquid chromatography (HPLC). Structural analysis, using mass spectrometry (MS), of a single active HPLC fraction revealed two known cyclic lipopeptides, BMY-28160 and permetin A, a new cyclic lipopeptide, and the linear counterparts of these cyclic compounds. The latter were designated as paenipeptin A, B and C, respectively...
February 25, 2017: FEMS Microbiology Letters
https://www.readbyqxmd.com/read/28332756/a-fluorescent-sensing-of-nerve-agent-simulant-with-dual-emissions-at-wide-ph-range-in-aqueous-solution
#6
Youngsam Kim, Yoon Jeong Jang, Sandip V Mulay, Thuy-Tien T Nguyen, David G Churchill
A new 1,8-naphthalimide-based fluorescent probe for the detection of diethyl cyanophosphonate, a very common nerve agent simulant, was designed, synthesized and characterized fully. The probe showed around 50-fold enhancement of fluorescence intensity over other nerve agent simulants. Importantly, the probe is able to work under aqueous conditions at wide pH range. Two reactive groups, the oxime and phenol, allowed a dual emission with different kinetic reaction. The reaction of diethyl cyanophosphonate with the oxime group occurred in advance; the resulting time-response of fluorescence enhancement was observed within ~30 s...
March 23, 2017: Chemistry: a European Journal
https://www.readbyqxmd.com/read/28332691/relaxations-and-phase-transitions-during-the-collapse-of-a-dense-pnipam-microgel-suspension-thorough-insight-using-dielectric-spectroscopy
#7
Man Yang, Chunyan Liu, Yiwei Lian, Kongshuang Zhao, Dan Zhu, Jianfeng Zhou
The dielectric behavior of a thermo-sensitive poly-(N-isopropylacrylamide) (PNIPAM) microgel suspension with a dense concentration was investigated over the frequency range of 40 Hz to 110 MHz in a wide temperature window of 10-60 °C. By successfully removing the electrode polarization effect from the original data, two remarkable and temperature-dependent relaxation processes were observed. Both of the two-phase transition processes, i.e., the colloidal crystal-to-liquid transition, which has not yet been detected by dielectric spectroscopy before, as well as the volume phase transition, were detected by the relaxation parameters...
March 23, 2017: Soft Matter
https://www.readbyqxmd.com/read/28330346/a-new-approach-to-molecular-dynamics-with-non-adiabatic-and-spin-orbit-effects-with-applications-to-qm-mm-simulations-of-thiophene-and-selenophene
#8
Marek Pederzoli, Jiří Pittner
We present surface hopping dynamics on potential energy surfaces resulting from the spin-orbit splitting, i.e., surfaces corresponding to the eigenstates of the total electronic Hamiltonian including the spin-orbit coupling. In this approach, difficulties arise because of random phases of degenerate eigenvectors and possibility of crossings of the resulting mixed states. Our implementation solves these problems and allows propagation of the coefficients both in the representation of the spin free Hamiltonian and directly in the "diagonal representation" of the mixed states...
March 21, 2017: Journal of Chemical Physics
https://www.readbyqxmd.com/read/28330345/coexistence-of-low-and-high-overlap-phases-in-a-supercooled-liquid-an-integral-equation-investigation
#9
Jean-Marc Bomont, Giorgio Pastore, Jean-Pierre Hansen
The pair structure, free energy, and configurational overlap order parameter Q of an annealed system of two weakly coupled replicas of a supercooled "soft sphere" fluid are determined by solving the hypernetted-chain (HNC) and self-consistent Rogers-Young (RY) integral equations over a wide range of thermodynamic conditions ρ (number-density), T (temperature), and inter-replicas couplings ε12. Analysis of the resulting effective (or Landau) potential W(ρ,T; Q) and of its derivative with respect to Q confirms the existence of a "precursor transition" between weak and strong overlap phases below a critical temperature Tc well above the temperature To of the "ideal glass" transition observed in the limit ε12→0...
March 21, 2017: Journal of Chemical Physics
https://www.readbyqxmd.com/read/28327724/reversible-crystal-to-crystal-chiral-resolution-making-breaking-non-bonding-so-interactions
#10
R Alex Mayo, David J Sullivan, Travis A P Fillion, Stefan W Kycia, Dmitriy V Soldatov, Kathryn E Preuss
An achiral organic molecule adopts a chiral conformation, crystallizing in two morphologies: a racemic form, stable <70 °C, and a homochiral form, stable ≥70 °C. Upon seeding, crystal-to-crystal phase transitions occur reversibly between the racemic and chiral forms. Liquid-to-solid chiral crystallization is observed >90% of the time from the melt.
March 22, 2017: Chemical Communications: Chem Comm
https://www.readbyqxmd.com/read/28326671/shape-assisted-self-organization-in-highly-disordered-liquid-crystal-phases
#11
Keiki Kishikawa, Yusuke Yamamoto, Go Watanabe, Ayaka Kawamura, Michinari Kohri, Tatsuo Taniguchi
In achiral rod-like molecules, a nematic phase is the most disordered liquid crystal phase, which only has one-directional order in the direction of the molecular long axis. A dumbbell-shaped molecule (compound 3: R-C6 H10 -CH=CH-C6 H4 -CH=CH-C6 H10 -R, (R=nC5 H11 )), and its liquid crystal phase (X phase) are reported, which exhibit high scattering without thermal fluctuation between two nematic phases under a polarized light optical microscope. The X phase was investigated by X-ray diffraction, scanning electron microscopy, atomic force microscopy, and molecular dynamics simulation...
March 22, 2017: Angewandte Chemie
https://www.readbyqxmd.com/read/28321989/expansion-of-the-%C3%AF-oxidation-system-alkbgtl-of-pseudomonas-putida-gpo1-with-alkj-and-alkh-results-in-exclusive-mono-esterified-dicarboxylic-acid-production-in-e-%C3%A2-coli
#12
Youri M van Nuland, Fons A de Vogel, Gerrit Eggink, Ruud A Weusthuis
The AlkBGTL proteins coded on the alk operon from Pseudomonas putida GPo1 can selectively ω-oxidize ethyl esters of C6 to C10 fatty acids in whole-cell conversions with Escherichia coli. The major product in these conversions is the ω-alcohol. However, AlkB also has the capacity to overoxidize the substrate to the ω-aldehyde and ω-acid. In this study, we show that alcohol dehydrogenase AlkJ and aldehyde dehydrogenase AlkH are able to oxidize ω-alcohols and ω-aldehydes of esterified fatty acids respectively...
March 20, 2017: Microbial Biotechnology
https://www.readbyqxmd.com/read/28320562/microstructural-characterization-of-dental-zinc-phosphate-cements-using-combined-small-angle-neutron-scattering-and-microfocus-x-ray-computed-tomography
#13
Alberto Viani, Konstantinos Sotiriadis, Ivana Kumpová, Lucia Mancini, Marie-Sousai Appavou
OBJECTIVE: To characterize the microstructure of two zinc phosphate cement formulations in order to investigate the role of liquid/solid ratio and composition of powder component, on the developed porosity and, consequently, on compressive strength. METHODS: X-ray powder diffraction with the Rietveld method was used to study the phase composition of zinc oxide powder and cements. Powder component and cement microstructure were investigated with scanning electron microscopy...
February 17, 2017: Dental Materials: Official Publication of the Academy of Dental Materials
https://www.readbyqxmd.com/read/28319022/recovery-of-lignin-peroxidase-from-submerged-liquid-fermentation-of-amauroderma-rugosum-blume-t-nees-torrend-using-polyethylene-glycol-salt-aqueous-two-phase-system
#14
Wan Yng Linda Jong, Pau Loke Show, Tau Chuan Ling, Yee Shin Tan
Amauroderma rugosum is a wild mushroom species widely distributed in tropics and is classified under the class of Basidiomycetes. Basidiomycetes are well-known for their abilities of producing lignocellulolytic enzymes such as lignin peroxidase (LiP), laccase (Lac) and manganese peroxidase (MnP). Different factors such as nutrient sources, incubation period and agitation affect the production of lignocellulolytic enzymes. The A. rugosum produced LiP in the medium supplemented with potato dextrose broth (PDB), 0...
March 16, 2017: Journal of Bioscience and Bioengineering
https://www.readbyqxmd.com/read/28318697/how-do-low-doses-of-desferrioxamine-b-and-edta-affect-the-phytoextraction-of-metals-in-sunflower
#15
J Y Cornu, C Dépernet, C Garnier, V Lenoble, A Braud, T Lebeau
The aim of this study was to compare the efficiency of siderophore desferrioxamine B (DFOB) and EDTA in increasing the phytoextraction of metals in sunflower. A 28-day pot experiment was conducted in a metal-contaminated soil supplied with 200μmolkg(-1) of DFOB or EDTA. Pore water was collected and pseudo-polarographic analyses were conducted to assess the impact of the two chelators on the mobility and speciation of metals in the liquid phase. Our results showed that DFOB is not an efficient mobilizing agent of divalent metals in soil...
March 15, 2017: Science of the Total Environment
https://www.readbyqxmd.com/read/28318258/molecular-dynamics-studies-on-liquid-vapor-interface-properties-and-structures-of-1-ethyl-3-methylimidazolium-dimethylphosphate-water
#16
Tianyu Li, Zongchang Zhao, Xiaodong Zhang, Xican Sun
1-ethyl-3-methylimidazolium dimethylphosphate ([Emim][Dmp])-water binary solution is one of the promising new working-pairs for absorption heat pump and absorption chillers, which are widely used to recover industrial waste heat. In the absorption process, the mass and heat transfer at the interface greatly depend on interface microscopes structure. Therefore, in order to understand the absorption process, it is very important to study the interface microscopes structure. The liquid-vapor interface properties, as well as the orientation of [Emim]+, [Dmp]-, water at the interface and its aqueous solution with different water mole fraction, were studied using classical all-atom force field by molecular dynamic simulations...
March 20, 2017: Journal of Physical Chemistry. B
https://www.readbyqxmd.com/read/28317939/direct-measurement-of-the-propagation-of-the-phase-transition-region-of-liquid-crystals
#17
Takahiro Sato, Kenji Katayama
Many types of active matter, such as biological cells, have liquid-crystalline membranes, which are soft and flexible in their interactions with their surroundings and sometimes allow molecular-structural or -orientational changes to extend for long distances, owing to long-range molecular interactions. Despite the technological and fundamental importance of these long-range changes, there is no good physical property with which to express them for the liquid crystal. Here, we show direct measurements of the propagation of structural or orientational changes due to long-range molecular interactions in liquid crystals...
March 20, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28317135/free-mycophenolic-acid-determination-in-human-plasma-ultrafiltrate-by-a-validated-liquid-chromatography-tandem-mass-spectrometry-method
#18
Paulina Łuszczyńska, Tomasz Pawiński, Paweł K Kunicki, Katarzyna Sikorska, Ryszard Marszałek
OBJECTIVES: The aim of this study was to develop and fully validate LC-MS/MS method for free mycophenolic acid (MPA) concentration measurements in plasma ultrafiltrate that will be reliable and simple in preparation with deuterated MPA (MPA-d3) chosen as an internal standard. METHODS: The chromatographic separation was made with Zorbax Eclipse XDB-C18 column (4.6x150 mm) using a gradient of two solutions as a mobile phase: A) water and B) methanol, each containing 0...
March 20, 2017: Biomedical Chromatography: BMC
https://www.readbyqxmd.com/read/28316050/adsorption-and-desorption-characteristics-of-endosulfan-in-two-typical-agricultural-soils-in-southwest-china
#19
Sheng Qian, Heng Zhu, Bailian Xiong, Guocan Zheng, Jinzhong Zhang, Weihong Xu
Endosulfan is an organochlorine pesticide widely used in Southwest China. In this paper, the adsorption and desorption characteristics of endosulfan in two typical agricultural soils (latosol and lateritic red soil) in this area were studied. The results showed that Langmuir isothermal equation could well describe the adsorption thermodynamic characteristics of endosulfan in latosol and lateritic red soil, and the maximum adsorption capacities of α-endosulfan were 0.186 and 0.209 mg/g, while those of β-endosulfan were 0...
March 18, 2017: Environmental Science and Pollution Research International
https://www.readbyqxmd.com/read/28315849/environmental-and-genetic-determinants-of-two-vitamin-d-metabolites-in-healthy-australian-children
#20
Abdulhadi Bima, Angela Pezic, Cong Sun, Fergus J Cameron, Christine Rodda, Ingrid van der Mei, Rachel Chiaroni-Clarke, Terence Dwyer, Andrew Kemp, Jun Qu, John Carlin, Justine A Ellis, Anne-Louise Ponsonby
BACKGROUND: Vitamin D deficiency has been associated with adverse health outcomes. We examined genetic and environmental determinants of serum 25(OH)D3 and 1,25(OH)2D3 in childhood. METHODS: The study sample consisted of 322 healthy Australian children (predominantly Caucasians) who provided a venous blood sample. A parental interview was conducted and skin phototype and anthropometry measures were assessed. Concentrations of 25(OH)D3 and 1,25(OH)2D3 were measured by selective solid-phase extraction-capillary liquid chromatography-tandem mass spectrometry...
March 20, 2017: Journal of Pediatric Endocrinology & Metabolism: JPEM
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