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formic acid

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https://www.readbyqxmd.com/read/28428821/genome-wide-search-for-candidate-genes-for-yeast-robustness-improvement-against-formic-acid-reveals-novel-susceptibility-trk1-and-positive-regulators-and-resistance-haa1-regulon-determinants
#1
Sílvia F Henriques, Nuno P Mira, Isabel Sá-Correia
BACKGROUND: Formic acid is an inhibitory compound present in lignocellulosic hydrolysates. Understanding the complex molecular mechanisms underlying Saccharomyces cerevisiae tolerance to this weak acid at the system level is instrumental to guide synthetic pathway engineering for robustness improvement of industrial strains envisaging their use in lignocellulosic biorefineries. RESULTS: This study was performed to identify, at a genome-wide scale, genes whose expression confers protection or susceptibility to formic acid, based on the screening of a haploid deletion mutant collection to search for these phenotypes in the presence of 60, 70 and 80 mM of this acid, at pH 4...
2017: Biotechnology for Biofuels
https://www.readbyqxmd.com/read/28426176/uhplc-ms-ms-method-for-the-simultaneous-quantitation-of-five-anthraquinones-and-gallic-acid-in-rat-plasma-after-oral-administration-of-prepared-rhubarb-decoction-and-its-application-to-a-pharmacokinetic-study-in-normal-and-acute-blood-stasis-rats
#2
Hui Zhu, Xiao Liu, Ting Ting Zhu, Xiao Li Wang, Kun Ming Qin, Ke Pei, Bao Chang Cai
Prepared rhubarb, as one of the main processed products of rhubarb, has a good effect on promoting blood circulation. This paper described a rapid, sensitive and selective ultra-fast liquid chromatography with tandem mass spectrometry method for simultaneous quantification of five anthraquinones (rhein, aloe-emodin, chrysophanol, emodin and physcion) and gallic acid in plasma. Chromatographic separation was performed on an Extend C18 column at the temperature of 30°C using the mobile phase consisted of 0.1% aqueous formic acid and acetonitrile...
April 20, 2017: Journal of Separation Science
https://www.readbyqxmd.com/read/28420232/gas-phase-carboxylic-acids-in-a-university-classroom-abundance-variability-and-sources
#3
Shang Liu, Samantha L Thompson, Harald Stark, Paul J Ziemann, Jose L Jimenez
Gas-phase carboxylic acids are ubiquitous in ambient air, yet their indoor occurrence and abundance are poorly characterized. To fill this gap, we measured gas-phase carboxylic acids in real-time inside and outside of a university classroom using a high-resolution time-of-flight chemical ionization mass spectrometer (HRToF-CIMS) equipped with an acetate ion source. A wide variety of carboxylic acids were identified indoors and outdoors, including monoacids, diacids, hydroxy acids, carbonyl acids, and aromatic acids...
April 18, 2017: Environmental Science & Technology
https://www.readbyqxmd.com/read/28419937/validation-and-application-of-an-ultrahigh-performance-liquid-chromatographic-orbitrap-mass-spectrometric-method-for-the-simultaneous-detection-and-quantification-of-volatile-and-non-volatile-organic-acids-in-human-faecal-samples
#4
Claudio Gardana, Cristian Del Bo', Paolo Simonetti
A simple and selective ultrahigh-performance liquid chromatographic-Orbitrap mass spectrometric (UHPLC-HR-MS) method was developed and validated for the simultaneous detection and quantification of short-chain fatty acids (SCFAs) such as acetic, propionic, butyric, isobutyric, valeric, isovaleric, 2-methyl-butyric (IS) and lactic, pyruvic and succinic acid in human faecal samples. A simple extraction procedure with 0.001% formic acid in water was performed on 40 samples. The extracts were centrifuged and analyzed by UHPLC-HR-MS on a sub-2μm column using gradient elution; meanwhile, the same samples were analyzed by GC-FID and HPLC-UV as reference methods The UHPLC-HR-MS method showed a recovery of 83-105%, a repeatability of 2...
April 10, 2017: Journal of Pharmaceutical and Biomedical Analysis
https://www.readbyqxmd.com/read/28415020/simultaneous-determination-of-ten-bioactive-constituents-of-sanjie-zhentong-capsule-in-rat-plasma-by-ultra-high-performance-liquid-chromatography-tandem-mass-spectrometry-and-its-application-to-a-pharmacokinetic-study
#5
Jiachun Li, Dongpo Li, Youzhi Pan, Jun-Hua Hu, Wenzhe Huang, Zhen-Zhong Wang, Wei Xiao, Yu Wang
Sanjie Zhentong capsule, a well-known traditional Chinese medicine prescription, are used for the treatment of endometriosis-related diseases. In this study, a simple, rapid and sensitive ultra-high-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) method was developed for the simultaneous determination of ten bioactive constituents, including peimine, peiminine, peimisine, loureirin A, loureirin B, 7,4'-dihydroxyflavone, pterostilbene, ginsenoside Rg1, ginsenoside Rb1, and notoginsenoside R1 in rat plasma after oral administration of Sanjie Zhentong capsule...
March 9, 2017: Journal of Chromatography. B, Analytical Technologies in the Biomedical and Life Sciences
https://www.readbyqxmd.com/read/28411692/quantitation-of-camellianin-a-in-hepg2-cells-using-a-high-performance-liquid-chromatography-electrospray-ionization-tandem-mass-spectrometric-method
#6
Qian-Qian Chen, Hai-Ling Xi, Cai-Yun Wang, Feng-Guo Xu, Wei Zhang
The present study was designed to develop a sensitive and selective high performance liquid chromatography-tandem mass spectrometric method for the determination of Camellianin A in HepG2 cells. The extraction of Camellianin A was achieved using 15% trichloroacetic acid and then separated on a C18 column interfaced with a triple quadrupole tandem mass spectrometer in multiple reaction monitoring mode. The mobile phase was consisted of methanol-water (0.1% formic acid) (55 : 45, V/V). The total run time was 5...
March 2017: Chinese Journal of Natural Medicines
https://www.readbyqxmd.com/read/28409868/validated-uhplc-ms-ms-assay-for-quantitative-determination-of-etoposide-gemcitabine-vinorelbine-and-their-metabolites-in-lung-cancer-patients
#7
Xiaobin Gong, Le Yang, Feng Zhang, Youtian Liang, Shouhong Gao, Ke Liu, Wansheng Chen
A fully valid ultra-high performance liquid chromatography coupled with mass spectrometry (UHPLC- MS/MS) method was developed for the determination of etoposide, gemcitabine, vinorelbine and their metabolites (etoposide catechol, 2',2'-difluorodeoxyuridine and 4-O-deacetylvinorelbine) in human plasma. Multiple reaction monitoring (MRM) mode was performed with an electrospray ionization (ESI) interface operating in both the positive and negative ion modes per compound. The method required only 100 μL plasma with a one-step simple de-proteinization procedure, and a short run time of 7...
April 13, 2017: Biomedical Chromatography: BMC
https://www.readbyqxmd.com/read/28405288/wood-ants-produce-a-potent-antimicrobial-agent-by-applying-formic-acid-on-tree-collected-resin
#8
Timothée Brütsch, Geoffrey Jaffuel, Armelle Vallat, Ted C J Turlings, Michel Chapuisat
Wood ants fight pathogens by incorporating tree resin with antimicrobial properties into their nests. They also produce large quantities of formic acid in their venom gland, which they readily spray to defend or disinfect their nest. Mixing chemicals to produce powerful antibiotics is common practice in human medicine, yet evidence for the use of such "defensive cocktails" by animals remains scant. Here, we test the hypothesis that wood ants enhance the antifungal activity of tree resin by treating it with formic acid...
April 2017: Ecology and Evolution
https://www.readbyqxmd.com/read/28403574/determination-of-artemisitene-in-rat-plasma-by-uplc-ms-ms-and-its-application-in-pharmacokinetics
#9
Lilan Wu, Yunshan Wu, Weiying Chen, Wen Zhou, Lipeng Tang, Ben Li, Bo Liu
RATIONALE: Artemisitene showed a wide variety of pharmacological activities, such as antioxidant protection in vitro and in vivo. It has been identified as a novel Nrf2 inducer. However, there is no report on an UPLC-MS/MS method to quantitate artemisitene in rat plasma and its application on pharmacokinetic profile study. METHODS: An ACQUITY UPLC(TM) BEH Symmetry ShieldRP18 column (1.7 µm, 2.1 mm × 100 mm) was used with a flow rate of 0.3 mL · min(-1) ...
April 12, 2017: Rapid Communications in Mass Spectrometry: RCM
https://www.readbyqxmd.com/read/28402632/agpd-nanoparticles-deposited-on-wo2-72-nanorods-as-an-efficient-catalyst-for-one-pot-conversion-of-nitrophenol-nitroacetophenone-into-benzoxazole-quinazoline
#10
Chao Yu, Xuefeng Guo, Zheng Xi, Michelle Muzzio, Zhouyang Yin, Bo Shen, Junrui Li, Christopher Seto, Shouheng Sun
We report a seed-mediated growth of 2.3 nm AgPd nanoparticles (NPs) in the presence of 40 × 5 nm WO2.72 nanorods (NRs) for the synthesis of AgPd/WO2.72 composites. The strong interactions between AgPd NPs and WO2.72 NRs make the composites, especially the Ag48Pd52/WO2.72, catalytically active for dehydrogenation of formic acid (TOF = 1718 h-1 and Ea = 31 kJ/mol), and one-pot reactions of formic acid, 2-nitrophenol and aldehydes into benzoxazoles in near quantitative yields under mild conditions. The catalysis can also be extended to the one-pot reactions of ammonium formate, 2-nitroacetophenone and aldehyde for high yield syntheses of quinazolines...
April 12, 2017: Journal of the American Chemical Society
https://www.readbyqxmd.com/read/28402027/simultaneous-determination-of-difenoconazole-trifloxystrobin-and-its-metabolite-trifloxystrobin-acid-residues-in-watermelon-under-field-conditions-by-gc%C3%A2-%C3%A2-ms-ms
#11
Di Kang, Haizhen Zhang, Yuling Chen, Fei Wang, Lihong Shi, Deyu Hu, Kankan Zhang
An optimized QuEChERS method for the simultaneous determination of difenoconazole, trifloxystrobin and its metabolite trifloxystrobin acid residues in watermelon and soil was developed and validated by gas chromatography with tandem mass spectrometry. The samples were extracted with acetonitrile (1% formic acid) and cleaned up by dispersive solid-phase extraction with octadecylsilane sorbent. The limit of quantification of the method was 0.01 mg/kg, and the limit of detection was 0.003 mg/kg for all three analytes...
April 12, 2017: Biomedical Chromatography: BMC
https://www.readbyqxmd.com/read/28399431/determination-of-azd3759-in-rat-plasma-and-brain-tissue-by-lc-ms-ms-and-its-application-in-pharmacokinetic-and-brain-distribution-studies
#12
Shan Xiong, Mingxing Xue, Yanling Mu, Zhipeng Deng, Peilu Sun, Ruican Zhou
A simple and sensitive high performance liquid chromatography with tandem mass spectrometry (LC-MS/MS) method for determination of AZD3759, a novel epidermal growth factor receptor tyrosine kinase inhibitor, in rat plasma and brain homogenate was developed and validated over the range of 1.0-1000ng/mL. Chromatographic separation was carried out on a C18 column with acetonitrile and 0.1% formic acid in water as mobile phase with gradient elution at a flow rate of 0.4mL/min. The lower limits of quantification (LLOQs) were 1...
March 31, 2017: Journal of Pharmaceutical and Biomedical Analysis
https://www.readbyqxmd.com/read/28395244/an-isocratic-hydrophilic-interaction-liquid-chromatographic-method-for-simultaneous-determination-of-iodixanol-and-its-related-impurities-in-drug-substance
#13
Bruno D Rondon, Neila M Cassiano, Quezia B Cass
This work reports a simple isocratic hydrophilic interaction liquid chromatographic (HILIC) method for the simultaneous quantification of iodixanol and of its related impurities C, D and E in drug substance. The chromatographic separation was carried out with a Kinetex™ HILIC column, using acetonitrile and formic acid aqueous solution (1.0mmol/L, pH 3.2) (92:08, v/v) as eluent at a flow rate of 0.8mL/min. The autosampler and column temperature were maintained at 20°C and UV detection was set at 243nm. The method was validated in accordance to the ICH guideline and employed for the analysis of two different lots of iodixanol drug substance...
March 24, 2017: Journal of Pharmaceutical and Biomedical Analysis
https://www.readbyqxmd.com/read/28391864/a-simple-and-high-throughput-method-for-determination-and-confirmation-of-14-coccidiostats-in-poultry-muscle-and-eggs-using-liquid-chromatography-quadrupole-linear-ion-trap-tandem-mass-spectrometry-hplc-qqlit-ms-ms-validation-according-to-european-union-2002
#14
Fabiano Barreto, Cristina Ribeiro, Rodrigo Barcellos Hoff, Teresa Dalla Costa
A simple and fast quantitative and confirmatory multi-residue method was developed and validated for the determination of 14 coccidiostats residues in poultry muscle and eggs using liquid chromatography-tandem mass spectrometry (LC/MS-MS). The compounds were analyzed in a single run including lasalocid A, maduramicin, monensin, narasin, salinomycin, semduramicin, robenidine, diclazuril, toltrazuril, trimethoprim, clopidol, amprolium, diaveridine and nicarbazin (as the marker residue dinitrocarbanilide). A low-cost extraction and clean up procedure was optimized without the need of solid-phase extraction...
June 1, 2017: Talanta
https://www.readbyqxmd.com/read/28383683/validated-lc-ms-ms-method-for-determination-of-sf0034-in-mice-plasma-application-to-a-pharmacokinetic-study-in-mice
#15
Umesh Todmal, P S Suresh, Mohd Zainuddin, Ravi Kanth Bhamidipati, Swapan Kumar Samanta, Gurulingappa Hallur, Sridharan Rajagopal, Sriram Rajagopal, Ramesh Mullangi
A rapid and sensitive assay method has been developed and validated using liquid chromatography coupled to tandem mass spectrometry with electrospray ionization in the positive-ion mode for the estimation of SF0034 in mice plasma. The assay procedure involves a simple protein precipitation of SF0034 and tolbutamide (internal standard, IS) from mice plasma. Chromatographic separation was performed on an Atlantis dC18 column using an isocratic mobile phase comprising 0.2% formic acid:acetonitrile (10:90, v/v) at a flow rate of 0...
April 5, 2017: Journal of Chromatographic Science
https://www.readbyqxmd.com/read/28383657/lc-ms-ms-determination-of-empagliflozin-and-metformin
#16
Bassam M Ayoub, Shereen Mowaka
A new LC-MS/MS method was developed for determination of empagliflozin and metformin. Bridged Ethylene Hybrid C18 column (50 mm × 2.1 mm, 1.7 μm), isocratic elution based on 0.1% aqueous formic acid:acetonitrile (75:25, v/v) as a mobile phase, column temperature at 55°C and flow rate at 0.2 mL min-1 were used. The mass spectrometer was operated under multiple reaction monitoring mode using electrospray ionization by monitoring the transition pairs (precursor to product ion) of m/z 451.04-71.07 for empagliflozin and m/z 130...
April 5, 2017: Journal of Chromatographic Science
https://www.readbyqxmd.com/read/28375636/dihydropteridine-pteridine-as-a-2h-2e-redox-mediator-for-the-reduction-of-co2-to-methanol-a-computational-study
#17
Chern-Hooi Lim, Aaron M Holder, James T Hynes, Charles B Musgrave
Conflicting experimental results for the electrocatalytic reduction of CO2 to CH3OH on a glassy carbon electrode by the 6,7-dimethyl-4-hydroxy-2-mercaptopteridine have been recently reported [ J. Am. Chem. Soc. 2014 , 136 , 14007 - 14010 , J. Am. Chem. Soc. 2016 , 138 , 1017 - 1021 ]. In this connection, we have used computational chemistry to examine the issue of this molecule's ability to act as a hydride donor to reduce CO2. We first determined that the most thermodynamically stable tautomer of this aqueous compound is its oxothione form, termed here PTE...
April 18, 2017: Journal of Physical Chemistry. B
https://www.readbyqxmd.com/read/28372838/development-and-validation-of-a-liquid-chromatography-tandem-mass-spectrometry-method-for-the-determination-of-cannabinoids-and-phase-i-and-ii-metabolites-in-meconium
#18
Pablo Prego-Meleiro, Elena Lendoiro, Marta Concheiro, Angelines Cruz, Manuel López-Rivadulla, Ana de Castro
A liquid chromatography-tandem mass spectrometry (LC-MSMS) method was developed and fully validated for the determination of Δ(9)-tetrahydrocannabinol (THC), 11-hydroxyTHC (OHTHC), 11-nor-9-carboxyTHC (THCCOOH), 8-β-11-dihydroxyTHC (diOHTHC), cannabinol, cannabidiol, and THC and THCCOOH glucuronides in 0.25±0.02g meconium. Samples were homogenized in methanol and subjected to cation exchange solid-phase extraction. Chromatographic separation was performed on a Kinetex C18 column (50 mm×2.1mm, 2.6μm) at 35°C, with a gradient of 0...
March 25, 2017: Journal of Chromatography. A
https://www.readbyqxmd.com/read/28372357/high-efficiency-microflow-and-nanoflow-negative-electrospray-ionization-of-peptides-induced-by-gas-phase-proton-transfer-reactions
#19
Marija Nišavić, Amela Hozić, Zdenko Hameršak, Martina Radić, Ana Butorac, Marija Duvnjak, Mario Cindrić
Liquid chromatography coupled with electrospray ionization mass spectrometry (ESI-MS) is routinely used in proteomics research. Mass spectrometry-based peptide analysis is performed de facto in positive-ion mode, except for the analysis of some post-translationally modified peptides (e.g., phosphorylation and glycosylation). Collected mass spectrometry data after peptide negative ionization analysis is scarce, because of a lack of negatively charged amino acid side-chain residues that would enable efficient ionization (i...
April 17, 2017: Analytical Chemistry
https://www.readbyqxmd.com/read/28371712/seasonal-evaluation-of-disinfection-by-products-throughout-two-full-scale-drinking-water-treatment-plants
#20
Xin Zhong, Chongwei Cui, Shuili Yu
Carbonyl compounds can occur alpha-hydrogens or beta-diketones substitution reactions with disinfectants contributed to halogenated by-products formation. The objective of this research was to study the occurrence and fate of carbonyl compounds as ozonation by-products at two full-scale drinking water treatment plants (DWTPs) using different disinfectants for one year. The quality of the raw water used in both plants was varied according to the season. The higher carbonyl compounds concentrations were found in raw water in spring...
March 28, 2017: Chemosphere
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