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https://www.readbyqxmd.com/read/28719816/sulfate-radical-induced-degradation-of-%C3%AE-2-adrenoceptor-agonists-salbutamol-and-terbutaline-phenoxyl-radical-dependent-mechanisms
#1
Lei Zhou, Mohamad Sleiman, Corinne Ferronato, Jean-Marc Chovelon, Pascal de Sainte-Claire, Claire Richard
The present study investigated the reactivity and oxidation mechanisms of salbutamol (SAL) and terbutaline (TBL), two typical β2-adrenoceptor agonists, towards sulfate radical (SO4(-)) by using photo-activated persulfate (PS). The reaction pathways and mechanisms were proposed based on products identification using high resolution HPLC-ESI-MS, laser flash photolysis (LFP) and molecular orbital calculations. The results indicated that SO4(-) was the dominant reactive species in the UV/PS process. The second-order rate constants of sulfate radical reaction with SAL and TBL were measured as (3...
July 14, 2017: Water Research
https://www.readbyqxmd.com/read/28719200/cis-pinonic-acid-oxidation-by-hydroxyl-radicals-in-the-aqueous-phase-under-acidic-and-basic-conditions-kinetics-and-mechanism
#2
Bartlomiej Witkowski, Tomasz Gierczak
Aqueous-phase oxidation of cis-pinonic acid (CPA) by hydroxyl radicals (OH) was studied using a relative rate technique under acidic and basic conditions. Liquid chromatography (LC) coupled to the negative electrospray ionization (ESI) quadrupole tandem mass spectrometry (MS/MS) was used to monitor a disappearance of CPA and reference compounds. The measured second order reaction rate coefficients of CPA with OH were: 3.6 ± 0.3 × 10(9) M(-1)s(-1) (pH=2) and 3.0 ± 0.3 × 10(9) M(-1)s(-1) (pH = 10) - combined uncertainties are 2σ...
July 18, 2017: Environmental Science & Technology
https://www.readbyqxmd.com/read/28719153/in-source-collision-induced-dissociation-is-cid-applications-issues-and-structure-elucidation-with-single-stage-mass-analyzers
#3
Jon F Parcher, Mei Wang, Amar G Chittiboyina, Ikhlas A Khan
A discussion of the definition, advantages and issues with the formation of ions in the transition region between an ESI source and the ion optics of a mass analyzer is presented. The various types of ions formed in the so-called in-source collision induced dissociation (IS-CID) process are illustrated. Applications of IS-CID with single-stage mass analyzers, such as structure elucidation and quantitation, are demonstrated. The discussion is illustrated by examples of the in-source fragmentation of ginkgolides, which are marker compounds found only in Ginkgo biloba...
July 18, 2017: Drug Testing and Analysis
https://www.readbyqxmd.com/read/28718960/chemical-uplc-esi-ms-ms-profiling-of-aconitum-alkaloids-and-their-metabolites-in-rat-plasma-and-urine-after-oral-administration-of-aconitum-carmichaelii-debx-root-extract
#4
Mingjie Zhang, Manman Wang, Jiajia Liang, Yongqing Wen, Zhili Xiong
In this paper, an ultra high performance liquid chromatography tandem mass spectrometric (UPLC-ESI-MS/MS) method in positive ion mode was established to systematically identify and to compare the major aconitum alkaloids and their metabolites in rat plasma and urine after oral administration of Fuzi extract. A total twenty-nine components including twenty-five C19 -diterpenoid alkaloids and four C20 -diterpenoid alkaloids were identified in Fuzi extract. Thirteen of the parent components and five metabolites were detected in rat plasma and sixteen parent compounds and six metabolites in urine...
July 18, 2017: Biomedical Chromatography: BMC
https://www.readbyqxmd.com/read/28718959/characterization-of-a-highly-al-3-selective-fluorescence-probe-based-on-naphthalimide-schiff-base-and-its-application-to-practical-water-samples
#5
Kesheng Shen, Shanshan Mao, Xinkui Shi, Fei Wang, Yuling Xu, Stephen Opeyemi Aderinto, Huilu Wu
A new fluorescent Al(3+) -probe, N-allyl-4-[3,3'-((2-aminoethyl)azanediyl)-bis(N´-(2-hydroxybenzylidene)propanehy-drazide)]-1,8-naphthalimide (L), was designed and synthesized based on 1,8-naphthalimide. The probe L contains 1,8-naphthalimide moiety as the fluorophore and a Schiff base as the recognition group. The structure of L was determined by single crystal X-ray. L emission at 526 nm increased on addition of Al(3+) under excitation wavelength at 350 nm. L exhibited high selectivity and sensitivity fluorescence emission towards to Al(3+) in ethanol/Tris-HCl buffer solution (1:1, v/v, pH = 7...
July 18, 2017: Luminescence: the Journal of Biological and Chemical Luminescence
https://www.readbyqxmd.com/read/28717933/a-novel-ms-cleavable-azo-cross-linker-for-peptide-structure-analysis-by-free-radical-initiated-peptide-sequencing-frips
#6
Claudio Iacobucci, Christoph Hage, Mathias Schäfer, Andrea Sinz
The chemical cross-linking/mass spectrometry (MS) approach is a growing research field in structural proteomics that allows gaining insights into protein conformations. It relies on creating distance constraints between cross-linked amino acid side chains that can further be used to derive protein structures. Currently, the most urgent task for designing novel cross-linking principles is an unambiguous and automated assignment of the created cross-linked products. Here, we introduce the homobifunctional, amine-reactive, and water soluble cross-linker azobisimidoester (ABI) as a prototype of a novel class of cross-linkers...
July 17, 2017: Journal of the American Society for Mass Spectrometry
https://www.readbyqxmd.com/read/28717896/optimization-of-lipid-extraction-and-analytical-protocols-for-uhplc-esi-hrms-based-lipidomic-analysis-of-adherent-mammalian-cancer-cells
#7
Huizhen Zhang, Yue Gao, Jiahong Sun, Shicheng Fan, Xinpeng Yao, Xiaorong Ran, Chuanqi Zheng, Min Huang, Huichang Bi
Lipidomics, which reveals comprehensive characterization of molecular lipids, is a rapidly growing technology used in biomedical research. Lipid extraction is a critical step in lipidomic analysis. However, the effectiveness of different lipid extract solvent systems from cellular samples still remains unclear. In the current study, the protocol of reverse-phase liquid chromatography mass spectrometry (LC/MS)-based lipidomics was optimized for extraction and detection of lipids from human pancreatic cancer cell line PANC-1...
July 17, 2017: Analytical and Bioanalytical Chemistry
https://www.readbyqxmd.com/read/28715030/a-chiral-binol-based-gemini-amphiphilic-gelator-and-its-specific-discrimination-of-native-arginine-by-gelation-in-water
#8
Lihua Jia, Jianxin Yin, Xiangfeng Guo, Guangzhou Cao, Xuhua Tian, Bo Zhu, Lin Pu
A novel axially chiral cationic Gemini amphiphile gelator (S1) derived from (S)-BINOL has been synthesized and characterized by (1)H NMR, (13)C NMR, ESI-MS and FT-IR analyses. The critical micelle concentration (CMC) of S1 was determined to be 0.21 mM in water at room temperature. A transparent hydrogel with S1 at 43 mM was obtained at room temperature and characterized using various methods including SEM, CD, fluorescence, (1)H NMR, FT-IR, and XRD. The results indicate that the hydrophobic effect of long alkyl chains, π-π stacking of naphthalene rings, and intermolecular hydrogen-bonding of the amide groups of S1 should be responsible for the hydrogel formation...
July 17, 2017: Soft Matter
https://www.readbyqxmd.com/read/28714930/environmental-tobacco-smoke-exposure-during-pregnancy-and-child-neurodevelopment
#9
Kinga Polanska, Anna Krol, Dorota Merecz-Kot, Danuta Ligocka, Karolina Mikolajewska, Fiorino Mirabella, Flavia Chiarotti, Gemma Calamandrei, Wojciech Hanke
The developing fetus is especially vulnerable to environmental toxicants, including tobacco constituents. The aim of this study was to assess the impact of environmental tobacco smoke (ETS) exposure during pregnancy on child neurodevelopment within the first two years of life. The study population consisted of 461 non-smoking pregnant women (saliva cotinine level <10 ng/mL). Maternal passive smoking was assessed based on the cotinine level in saliva analyzed by the use of high-performance liquid chromatography coupled with tandem mass spectrometry (HPLC-ESI + MS/MS) and by questionnaire data...
July 17, 2017: International Journal of Environmental Research and Public Health
https://www.readbyqxmd.com/read/28714776/tissue-localization-of-glycosphingolipid-accumulation-in-a-gaucher-disease-mouse-brain-by-lc-esi-ms-ms-and-high-resolution-maldi-imaging-mass-spectrometry
#10
E Ellen Jones, Wujuan Zhang, Xueheng Zhao, Cristine Quiason, Stephanie Dale, Sheerin Shahidi-Latham, Gregory A Grabowski, Kenneth D R Setchell, Richard R Drake, Ying Sun
To better understand regional brain glycosphingolipid (GSL) accumulation in Gaucher disease (GD) and its relationship to neuropathology, a feasibility study using mass spectrometry and immunohistochemistry was conducted using brains derived from a GD mouse model (4L/PS/NA) homozygous for a mutant GCase (V394L [4L]) and expressing a prosaposin hypomorphic (PS-NA) transgene. Whole brains from GD and control animals were collected using one hemisphere for MALDI FTICR IMS analysis and the other for quantitation by LC-ESI-MS/MS...
July 1, 2017: SLAS Discovery
https://www.readbyqxmd.com/read/28712850/ex-vivo-instability-of-glycated-albumin-a-role-for-autoxidative-glycation
#11
Joshua W Jeffs, Shadi Ferdosi, Hussein N Yassine, Chad R Borges
Ex vivo protein modifications occur within plasma and serum (P/S) samples due to prolonged exposure to the thawed state-which includes temperatures above -30 °C. Herein, the ex vivo glycation of human serum albumin from healthy and diabetic subjects was monitored in P/S samples stored for hours to months at -80 °C, -20 °C, and room temperature, as well as in samples subjected to multiple freeze-thaw cycles, incubated at different surface area-to-volume ratios or under different atmospheric compositions...
July 13, 2017: Archives of Biochemistry and Biophysics
https://www.readbyqxmd.com/read/28712549/determination-of-trace-amounts-of-g-type-nerve-agents-in-aqueous-samples-utilizing-in-vial-instantaneous-derivatization-and-liquid-chromatography-tandem-mass-spectrometry
#12
Avi Weissberg, Moran Madmon, Maor Elgarisi, Shai Dagan
A methodology for sensitive determination of sarin (GB), soman (GD) and cyclosarin (GF) chemical warfare agents in aqueous media was developed. The method incorporates direct derivatization with 2-[(dimethylamino)methyl]phenol (2-DMAMP), a commercially available, water-soluble reagent, followed by LC-ESI-MS/MS analysis in the positive ion mode. Five derivatization agents were characterized for their MS/MS fragmentation pattern, and their reaction time, temperature and derivatization-reagent amount were optimized...
July 4, 2017: Journal of Chromatography. A
https://www.readbyqxmd.com/read/28711706/haemolytic-activity-of-formyl-and-acetyl-derivatives-of-bile-acids-and-their-gramine-salts
#13
Weronika Kozanecka-Okupnik, Beata Jasiewicz, Tomasz Pospieszny, Monika Matuszak, Lucyna Mrówczyńska
Bile acids (lithocholic: LCA, deoxycholic: DCA and cholic: CA) and their formyl- and acetyl- derivatives can be used as starting material in chemical synthesis of compounds with different biological activity strongly depended on their chemical structures. Our previous studies showed that biological activity of bile acids salts with gramine toward human erythrocytes was significantly different from the activity of bile acids alone. Moreover, gramine effectively modified the membrane perturbing activity of other steroids...
July 12, 2017: Steroids
https://www.readbyqxmd.com/read/28710594/addressing-a-common-misconception-ammonium-acetate-as-neutral-ph-buffer-for-native-electrospray-mass-spectrometry
#14
Lars Konermann
Native ESI-MS involves the transfer of intact proteins and biomolecular complexes from solution into the gas phase. One potential pitfall is the occurrence of pH-induced changes that can affect the analyte while it is still surrounded by solvent. Most native ESI-MS studies employ neutral aqueous ammonium acetate solutions. It is a widely perpetuated misconception that ammonium acetate buffers the analyte solution at neutral pH. By definition, a buffer consists of a weak acid and its conjugate weak base. The buffering range covers the weak acid pKa ± 1 pH unit...
July 14, 2017: Journal of the American Society for Mass Spectrometry
https://www.readbyqxmd.com/read/28710552/the-african-froghopper-ptyelus-flavescens-suborder-cicadomorpha-contains-two-novel-and-one-known-peptides-of-the-adipokinetic-hormone%C3%A2-akh-family-structure-function-and-comparison-with-aphid-akh-suborder-sternorrhyncha
#15
Gerd Gäde, Petr Šimek, Heather G Marco
The rationale of "green pesticides" in food security is to use information about endogenous hormones of pest insects to make peptide mimetics that will act against the pest insects to alter their behaviour or physiology, while taking care not to harm beneficial insects or other organisms in the food chain. Such "green" insecticides are designed thus, on the basis of neuropeptide ligand-receptor interaction and it is of paramount interest to have finally a mimetic at hand that is harmful only to pest insects...
July 14, 2017: Amino Acids
https://www.readbyqxmd.com/read/28710515/quantitative-lc-esi-srm-ms-of-antibody-biopharmaceuticals-use-of-a-homologous-antibody-as-an-internal-standard-and-three-step-method-development
#16
Fumio Osaki, Kenji Tabata, Tomoyuki Oe
Monoclonal antibody-based therapeutic agents (antibody drugs) have attracted considerable attention as a new type of drug. Concomitantly, the use of quantitative approaches for characterizing antibody drugs, such as liquid chromatography (LC)-mass spectrometry (MS), has increased. Generally, selective quantification of antibody drugs is done using unique peptides from variable regions (V H and V L) as surrogate peptides. Further, numerous internal standards (ISs) such as stable isotope-labeled (SIL)-intact proteins and SIL-surrogate peptides are used...
July 14, 2017: Analytical and Bioanalytical Chemistry
https://www.readbyqxmd.com/read/28709708/functional-proteomics-of-light-harvesting-complex-proteins-under-varying-light-conditions-in-diatoms
#17
Claudia Büchel, Christian Wilhelm, Volker Wagner, Maria Mittag
Comparative proteome analysis of subcellular compartments like thylakoid membranes and their associated supercomplexes can deliver important in-vivo information on the molecular basis of physiological functions which go far beyond to that what can be learnt from transcriptional-based gene expression studies. For instance, the finding that light intensity influences mainly the relative stoichiometry of subunits could be obtained only by high resolution proteome analysis. The high sensitivity of LC-ESI-MS/MS based proteome analysis allows the determination of proteins in very small subfractions along with their non-labeled semi quantitative analysis...
July 4, 2017: Journal of Plant Physiology
https://www.readbyqxmd.com/read/28709649/analysis-of-oxylipins-in-human-plasma-comparison-of-ultrahigh-performance-liquid-chromatography-and-ultrahigh-performance-supercritical-fluid-chromatography-coupled-to-mass-spectrometry
#18
Róbert Berkecz, Miroslav Lísa, Michal Holčapek
The potential of ultrahigh-performance liquid chromatography-mass spectrometry (UHPLC/MS) and ultrahigh-performance supercritical fluid chromatography (UHPSFC) coupled to negative-ion electrospray ionization mass spectrometry (ESI-MS) for the analysis of 46 oxylipins and 2 fatty acid standards is compared in terms of their chromatographic resolution with the emphasis on distinguishing isobaric interferences and the method sensitivity. UHPLC provides the baseline separation of 24 isobaric oxylipins within 13min, while UHPSFC enables the separation of only 20 isobaric oxylipins within 8min...
June 29, 2017: Journal of Chromatography. A
https://www.readbyqxmd.com/read/28709128/identification-and-interconversion-of-isomeric-4-5-functionalized-1-2-3-thiadiazoles-and-1-2-3-triazoles-in-conditions-of-electrospray-ionization
#19
D M Mazur, M E Zimens, V A Bakulev, A T Lebedev
1,2,3-Triazoles and 1,2,3-thiadiazoles have been receiving permanent interest due to their exciting chemical reactivity and interesting biological properties including antibacterial, anticancer and antiviral activities. There are four compounds bearing 1H-1,2,3-triazole core in clinical studies which may appear in the market of drugs in nearest future. Definitely reliable methods of their identification and quantification should be developed by that time. Mass spectrometry showed itself as the most reliable method of analysis when dealing with trace levels of organic compounds in the mixtures and in the most complex matrices, including biological ones...
July 8, 2017: Journal of Pharmaceutical and Biomedical Analysis
https://www.readbyqxmd.com/read/28708940/the-street-like-synthesis-of-krokodil-results-in-the-formation-of-an-enlarged-cluster-of-known-and-new-morphinans-with-therapeutic-potential
#20
José Soares, Emanuele Alves, André Silva, Natália Figueiredo, João F Neves, Sara Cravo, Maria Rangel, Annibal Netto, Félix Carvalho, Ricardo Jorge Dinis-Oliveira, Carlos Afonso
"Krokodil" is the street name for a homemade injectable drug that has been used as a cheap substitute for heroin. Codeine is the opioid starting material for krokodil synthesis and desomorphine is the opioid claimed to be the main component of krokodil and the main responsible for its addictive and psychoactive characteristics. However, due to its peculiar manufacture, using cheap raw materials, krokodil is composed by a large and complex mixture of different substances. In order to shed some light upon the chemical complexity of krokodil, its profiling was conducted by reverse phase high performance liquid chromatography coupled to photodiode array detector (RP-HPLC-DAD) and by liquid chromatography coupled to high resolution tandem mass spectrometry (LC-ESI-IT-Orbitrap-MS)...
July 14, 2017: Chemical Research in Toxicology
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