keyword
MENU ▼
Read by QxMD icon Read
search

LC/MS/MS

keyword
https://www.readbyqxmd.com/read/28454058/identification-and-characterization-of-process-related-substances-and-degradation-products-in-apremilast-process-optimization-and-degradation-pathway-elucidation
#1
Yuting Lu, Xiaoyue Shen, Taijun Hang, Min Song
This study aims at investigating the separation, identification and characterization of related substances in apremilast by LC-MS hyphenated techniques, as well as the synthesis optimization and the degradation pathways elucidation. Forced degradation studies were conducted under the ICH prescribed stress conditions. The chromatographic separation was achieved on XBridge C18 column (4.6mm×150mm, 3.5μm) using a mobile phase consisting of water adjusted to pH 3.0 with formic acid as solvent A and acetonitrile as solvent B in linear gradient elution program...
April 2, 2017: Journal of Pharmaceutical and Biomedical Analysis
https://www.readbyqxmd.com/read/28454030/pesticide-impact-study-in-the-peri-urban-horticultural-area-of-gran-la-plata-argentina
#2
Tomás M Mac Loughlin, Leticia Peluso, Damián J G Marino
Vegetable production systems are characterized by intense pesticide use, yet the effects on the surrounding environment are largely unknown and need to be studied. Given this knowledge gap, the objective of this work is to determine the impact of horticulture on a representative watercourse by conducting an integrated study of the occurrence and concentration of pesticides in bottom sediments and their relation to lethal and sublethal effects on benthic fauna. Two sampling campaigns were conducted during seasons of low and high pesticide application in five sites along the Carnaval creek, located in the peri-urban area of La Plata City (Buenos Aires, Argentina)...
April 25, 2017: Science of the Total Environment
https://www.readbyqxmd.com/read/28453518/lc-ms-ms-quantitative-analysis-reveals-the-association-between-fto-and-dna-methylation
#3
Yuting Zhu, Guangyu Zhou, Xuebin Yu, Qiang Xu, Kai Wang, Dan Xie, Qingkai Yang, Lina Wang
Fat mass and obesity-associated protein (FTO) is α-ketoglutarate-dependent dioxygenase and responsible for demethylating N6-methyladenosine (m6A) in mRNA, 3-methylthymine (m3T) in single-stranded DNA (ssDNA) and 3-methyluracil (m3U) in single-stranded RNA (ssRNA). Its other function remains unknown but thousands of mammalian DNA show 5-methyl-2'-deoxycytidine (5mdC) modification and 5mdC demethylases are required for mammalian energy homeostasis and fertility. Here, we aimed to confirm whether FTO proteins can demethylate 5mdC in DNA...
2017: PloS One
https://www.readbyqxmd.com/read/28453289/identification-of-buctopamine-and-mebuctopamine-a-%C3%AE-2-receptor-agonist-and-its-metabolite-in-swine-hair-and-feed-additives
#4
Ying-Heng Chen, Chia-Ying Yang, Chih Wen Cheng, Yi-Ying Lin, Su Lien Kuo, Ling-Wei Hsin
4-[2-(tert-Butylamino)-1-hydroxyethyl]phenol (buctopamine, 4), a new β2 receptor agonist (β2-agonist), was found to be an adulterant in feed additives for swine in Taiwan, where using β2-agonists in food-production animals is prohibited. Buctopamine and its metabolite, 4-[2-(tert-butylamino)-1-hydroxyethyl]-2-methoxyphenol (mebuctopamine, 2), were detected in swine hair specimens. Authentic compounds 2 and 4 were synthesized with 98.6% and 97.7% purity, respectively, as reference standards for analysis, and both compounds were more hydrophilic than ractopamine and clenbuterol...
April 28, 2017: Journal of Agricultural and Food Chemistry
https://www.readbyqxmd.com/read/28453257/one-filter-one-sample-and-the-n-and-o-glyco-proteo-me-towards-a-system-to-study-disorders-of-protein-glycosylation
#5
Kirsty Skeene, Matthew Walker, Graham Clarke, Ed Bergstrom, Paul Genever, Daniel Ungar, Jane Thomas-Oates
A method has been developed for release/isolation of O-glycans from glycoproteins in whole cell lysates, for mass spectrometric analysis. Cells are lysed in SDS, which is then exchanged for urea and ammonium bicarbonate in a centrifugal filter, before treating with NH4OH to release O-glycans. Following centrifugation, O-glycans are recovered in the filtrate. Sonication achieves O-glycan release in 1 h. Combining the established protocol for filter-aided N-glycan separation, here optimised for enhanced PNGase F efficiency, with the developed O-glycan release method allows analysis of both N- and O-glycans from one sample, in the same filter unit, from 0...
April 28, 2017: Analytical Chemistry
https://www.readbyqxmd.com/read/28453249/complete-mapping-of-complex-disulfide-patterns-with-closely-spaced-cysteines-by-in-source-reduction-and-data-dependent-mass-spectrometry
#6
Christian Necip Cramer, Christian D Kelstrup, Jesper Velgaard Olsen, Kim F Haselmann, Peter Kresten Nielsen
Mapping of disulfide bonds is an essential part of protein characterization to ensure correct cysteine pairings. For this, mass spectrometry (MS) is the most widely used technique due to fast and accurate characterization. However, MS-based disulfide mapping is challenged when multiple disulfide bonds are present in complicated patterns. This includes presence of disulfide bonds in nested patterns and closely-spaced cysteines. Unambiguous mapping of such disulfide bonds typically requires advanced MS approaches...
April 28, 2017: Analytical Chemistry
https://www.readbyqxmd.com/read/28449378/analysis-of-toldimfos-in-porcine-muscle-and-bovine-milk-using-liquid-chromatography-triple-quadrupole-mass-spectrometry
#7
Dan Zhang, Jin-A Park, A M Abd El-Aty, Seong-Kwan Kim, Sang-Hyun Cho, Weijia Zheng, Jeong-Min Choi, Jae-Han Shim, Byung-Joon Chang, Jin-Suk Kim, Ho-Chul Shin
An analytical method was developed for the detection of toldimfos sodium residues in porcine muscle and bovine milk using liquid chromatography-triple quadrupole tandem mass spectrometry (LC-MS/MS) analysis. The drug was extracted from muscle and milk using 10 mM ammonium formate in acetonitrile and then purified using n-hexane. The drug was well separated on a Luna C18 column using a mixture of 10 mM ammonium formate in ultrapure water (A) and acetonitrile (B) as the mobile phase. Good linearity was achieved over the tested concentration range (0...
April 27, 2017: Biomedical Chromatography: BMC
https://www.readbyqxmd.com/read/28448886/new-analytical-method-for-determination-of-epimer-metabolites-in-rat-plasma-after-oral-administration-of-paeoniflorin-by-uplc-tof-ms-following-picolinoyl-derivatization
#8
Zhigang Wang, Shuhan Tang, Masao Hattori, Hailong Zhang, Ping Wang, Xiuhong Wu, Ning Zhang
A highly sensitive analytical method was developed to study the in vivo metabolism of paeoniflorin, one of the most principal components in traditional Chinese medicine. After hydrolyzation with sulfatase, the epimer metabolites 7S-paeonimetabolin I and 7R-paeonimetabolin I of paeoniflorin in rat plasma were successfully detected and well separated by LC-MS following picolinoyl derivatization for the first time. Borneol was used as the internal standard to quantify 7S-paeonimetabolin I and 7R-paeonimetabolin I in rat plasma...
April 19, 2017: Journal of Pharmaceutical and Biomedical Analysis
https://www.readbyqxmd.com/read/28448885/development-and-validation-of-a-liquid-chromatographic-method-for-the-analysis-of-squaric-acid-dibutyl-ester-and-its-impurities
#9
Marwa F Mansour, Peixi Zhu, Ann Van Schepdael, Erwin Adams
A simple, fast and selective stability indicating liquid chromatographic method has been described for the simultaneous determination of squaric acid dibutyl ester and its impurities. The chromatographic separation was achieved on a C2 column (250mm×4.6mm i.d., 5μm) using a mobile phase consisting of 0.15% phosphoric acid - acetonitrile - methanol (30:60:10, v/v/v). Isocratic elution was performed at a flow rate of 1.0mLmin(-1). The analytes were detected by UV at 252nm. The method was validated according to the ICH guidelines and satisfactory results were obtained...
April 18, 2017: Journal of Pharmaceutical and Biomedical Analysis
https://www.readbyqxmd.com/read/28448799/isolation-of-antioxidant-phenolics-from-schinopsis-brasiliensis-based-on-a-preliminary-lc-ms-profiling
#10
Clisiane Carla de Souza Santos, Milena Masullo, Antonietta Cerulli, Angela Mari, Charles Dos Santos Estevam, Cosimo Pizza, Sonia Piacente
The phenolic content of the ethanol extract of the stem bark of the Brazilian plant Schinopsis brasiliensis Engl. (Anacardiaceae) has been evaluated together with the antioxidant activity. The good antioxidant activity exhibited in the Trolox Equivalent Antioxidant Capacity (TEAC) assay (TEAC value = 3.04 mg/mL) encouraged us to investigate its constituents. An analytical approach based on LC-ESIMS(n) was applied to rapidly obtain a metabolite profile of the ethanol extract of the stem bark of S. brasiliensis...
April 24, 2017: Phytochemistry
https://www.readbyqxmd.com/read/28448505/polyphenolic-extract-of-insp-5-ptase-expressing-tomato-plants-reduce-the-proliferation-of-mcf-7-breast-cancer-cells
#11
Mohammad Alimohammadi, Mohamed Hassen Lahiani, Diamond McGehee, Mariya Khodakovskaya
In recent years, by extensive achievements in understanding the mechanisms and the pathways affected by cancer, the focus of cancer research is shifting from developing new chemotherapy methods to using natural compounds with therapeutic properties to reduce the adverse effects of synthetic drugs on human health. We used fruit extracts from previously generated human type I InsP 5-ptase gene expressing transgenic tomato plants for assessment of the anti-cancer activity of established genetically modified tomato lines...
2017: PloS One
https://www.readbyqxmd.com/read/28448137/profiling-the-phenolic-compounds-of-the-four-major-seed-coat-types-and-their-relation-to-color-genes-in-lentil
#12
Mahla Mirali, Randy W Purves, Albert Vandenberg
Phenolic compounds can provide antioxidant health benefits for humans, and foods such as lentils can be valuable dietary sources of different subclasses of these secondary metabolites. This study used LC-MS analyses to compare the phenolic profiles of lentil genotypes with four seed coat background colors (green, gray, tan, and brown) and two cotyledon colors (red and yellow) grown at two locations. The mean area ratio per mg sample (MARS) values of various phenolic compounds in lentil seeds varied with the different seed coat colors conferred by specific genotypes...
April 27, 2017: Journal of Natural Products
https://www.readbyqxmd.com/read/28448110/heavy-metals-induce-decline-of-derivatives-of-5-methycytosine-in-both-dna-and-rna-of-stem-cells
#13
Jun Xiong, Xiaona Liu, Qing-Yun Cheng, Shan Xiao, Lai-Xin Xia, Bifeng Yuan, Yu-Qi Feng
Toxic heavy metals have been considered to be harmful environmental contaminations. The molecular mechanisms of heavy metals-induced cytotoxicity and carcinogenicity are still not well elucidated. Previous reports showed exposures to toxic heavy metals can cause change of DNA cytosine methylation (5-methylcytosine, 5-mC). However, it is still not clear whether heavy metals have effects on the recently identified new epigenetic marks in both DNA and RNA, i.e., 5-hydroxymethylcytosine (5-hmC), 5-formylcytosine (5-foC), and 5-carboxylcytosine (5-caC)...
April 27, 2017: ACS Chemical Biology
https://www.readbyqxmd.com/read/28448054/lipid-droplet-isolation-for-quantitative-mass-spectrometry-analysis
#14
Kathrin Rösch, Marcel Kwiatkowski, Hartmut Schlüter, Eva Herker
Lipid droplets are vital to the replication of a variety of different pathogens, most prominently the Hepatitis C Virus (HCV), as the putative site of virion morphogenesis. Quantitative lipid droplet proteome analysis can be used to identify proteins that localize to or are displaced from lipid droplets under conditions such as virus infections. Here, we describe a protocol that has been successfully used to characterize the changes in the lipid droplet proteome following infection with HCV. We use Stable Isotope Labeling with Amino Acids in Cell Culture (SILAC) and thus label the complete proteome of one population of cells with "heavy" amino acids to quantitate the proteins by mass spectrometry...
April 17, 2017: Journal of Visualized Experiments: JoVE
https://www.readbyqxmd.com/read/28447779/performance-and-mechanism-of-piezo-catalytic-degradation-of-4-chlorophenol-finding-of-effective-piezo-dechlorination
#15
Shenyu Lan, Jinxi Feng, Ya Xiong, Shuanghong Tian, Shengwei Liu, Lingjun Kong
Piezo-catalysis was first used to degrade a non-dye pollutant, 4-chlorophenol (4-CP). In this process, hydrothermally synthesized tetragonal BaTiO3 nano/micrometer-sized particles were used as the piezo-catalyst and the ultrasonic irradiation with low frequency was selected as the vibration energy to cause the deformation of tetragonal BaTiO3. It was found that the piezoelectric potential from the deformation could not only successfully degrade 4-chlorophenol, but also effectively make it dechlorination at the same time...
April 27, 2017: Environmental Science & Technology
https://www.readbyqxmd.com/read/28447619/little-cigars-are-more-toxic-than-cigarettes-and-uniquely-change-the-airway-gene-and-protein-expression
#16
Arunava Ghosh, Sabri H Abdelwahab, Steven L Reeber, Boris Reidel, Abigail J Marklew, Andrew J Garrison, Shernita Lee, Hong Dang, Amy H Herring, Gary L Glish, Mehmet Kesimer, Robert Tarran
Little cigars (LCs) are regulated differently than cigarettes, allowing them to be potentially targeted at youth/young adults. We exposed human bronchial epithelial cultures (HBECs) to air or whole tobacco smoke from cigarettes vs. LCs. Chronic smoke exposure increased the number of dead cells, lactate dehydrogenase release, and interleukin-8 (IL-8) secretion and decreased apical cilia, cystic fibrosis transmembrane conductance regulator (CFTR) protein levels, and transepithelial resistance. These adverse effects were significantly greater in LC-exposed HBECs than cigarette exposed cultures...
April 27, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28447397/an-lc-ms-ms-method-for-determination-of-bioactive-components-of-licorice-and-semen-strychni-in-rat-plasma-application-to-a-pharmacokinetics-study
#17
Min Zhang, Yang Deng, Chao Wang, Hua-Lin Cai, Jing-Wen, Ping-Fei Fang, Bi-Kui Zhang, Huan-De Li, Miao Yan
Semen Strychni is known for its treatment of rheumatic arthritis with a low therapeutic index. Licorice contributes a lot in herb detoxification according to the traditional Chinese medicine theory. A simple, rapid and sensitive liquid chromatography-mass spectrometric method was developed and validated for simultaneous determination of main bioactive ingredients in licorice and Semen Strychni in rat plasma. Using moclobemide and cyproterone acetate as the internal standards, the analytes were pretreated via protein precipitation with methanol...
April 26, 2017: Drug Testing and Analysis
https://www.readbyqxmd.com/read/28447255/phenolic-compounds-volatiles-and-antioxidant-capacity-of-white-myrtle-berry-liqueurs
#18
Gabriele Serreli, Igor Jerković, Katarzyna Angelika Gil, Zvonimir Marijanović, Viviana Pacini, Carlo Ignazio Giovanni Tuberoso
The aim of this research was to evaluate the antioxidant capacity and physical-chemical characteristics of commercial white myrtle berry (Myrtus communis L. var. leucocarpa DC) liqueur (WMBL). The total phenolic (TP) content was measured spectrophotometrically, applying a modified Folin-Ciocalteu's method, and phenolic compounds were identified by high-performance liquid chromatography (HPLC) coupled with electrospray mass spectrometry, and quantified by HPLC coupled with ultraviolet/visible detection. The antioxidant capacities were evaluated by FRAP, CUPRAC, DPPH(•), and ABTS(•+) assays...
April 26, 2017: Plant Foods for Human Nutrition
https://www.readbyqxmd.com/read/28446744/levetiracetam-pharmacokinetics-in-a-patient-with-intracranial-hemorrhage-undergoing-continuous-veno-venous-hemofiltration
#19
Edward T Van Matre, Scott W Mueller, Douglas N Fish, Robert MacLaren, Luis F Cava, Robert T Neumann, Tyree H Kiser
BACKGROUND Levetiracetam is an antiepileptic drug frequently used in critically ill patients. Levetiracetam is primarily eliminated as a parent compound via glomerular filtration and requires dose adjustment in renal insufficiency, but the literature on patients receiving continuous veno-venous hemofiltration (CVVH) is scant. CASE REPORT We report the levetiracetam pharmacokinetic profile of a patient being treated with levetiracetam 1000 mg intravenously every 12 h who required continuous veno-venous hemofiltration (CVVH)...
April 27, 2017: American Journal of Case Reports
https://www.readbyqxmd.com/read/28446328/combined-gc-and-uhplc-hr-ms-based-metabolomics-to-analyze-durable-anti-fungal-resistance-processes-in-cereals
#20
Rahel Bucher, Daniel Veyel, Lothar Willmitzer, Simon Krattinger, Beat Keller, Laurent Biglera
Introduction of durable resistance genes in crops is an important strategy to prevent yield loss caused by pathogens. The durable multi-pathogen resistance gene Lr34 originating from wheat is widely used in breeding, and is functionally transferable to barley and rice. The molecular resistance mechanism of Lr34, encoding for an adenosine triphosphate-binding cassette transporter, is not known yet. To understand the molecular function and the defense response of durable disease resistance in cereals, the metabolic response of Lr34 was investigated in, except for the Lr34 gene, genetically identical lines of barley, rice and wheat...
April 26, 2017: Chimia
keyword
keyword
34257
1
2
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read
×

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"