keyword
MENU ▼
Read by QxMD icon Read
search

LC/MS/MS

keyword
https://www.readbyqxmd.com/read/28934681/simultaneous-determination-of-gentiopicroside-and-its-two-active-metabolites-in-rat-plasma-by-lc-ms-ms-and-its-application-in-pharmacokinetic-studies
#1
Kai Xiong, Tingting Gao, Tong Zhang, Zhengtao Wang, Han Han
Gentiopicroside is a natural secoiridoid glycoside that may require metabolic activation to exert pharmacological effects. In this study, two active metabolites of gentiopicroside (M1 and M2) were isolated from rat urines and identified with our previous method. Most importantly, a fast, sensitive and selective ultra high-performance liquid chromatography-tandem mass spectrometry method was developed to simultaneously determine gentiopicroside and its two metabolites in rat plasma. The analytes and internal standard (swertiamarin) were separated on an ACQUITY UPLC(®) BEH C18 column (2...
September 14, 2017: Journal of Chromatography. B, Analytical Technologies in the Biomedical and Life Sciences
https://www.readbyqxmd.com/read/28934629/lacking-linearity-in-quantitative-stable-isotope-lc-ms-ms-measurement-of-f2-isoprostanes-is-an-irrefutable-indicator-of-analytical-inadequacy
#2
Dimitrios Tsikas, Erik Hanff
In LC-MS/MS-basedquantitative analysis of biological substances such as the F2-isoprostanes including 8-iso-prostaglandin F2α (i.e., 8-iso-PGF2α) use of stable-isotope labelled analogues at matrix-relevant concentrations is indispensable, enables linearity in relevant concentration ranges, and minimizes matrix effects. The quality of the linearity of calibration curves is an indicator of the analytical reliability of the LC-MS/MS method. Poor linearity is a convincing evidence of lacking analytical reliability...
September 8, 2017: Journal of Chromatography. B, Analytical Technologies in the Biomedical and Life Sciences
https://www.readbyqxmd.com/read/28934207/evaluation-of-the-pharmacokinetic-pharmacodynamic-relationship-of-praziquantel-in-the-schistosoma-mansoni-mouse-model
#3
Nada Abla, Jennifer Keiser, Mireille Vargas, Natalie Reimers, Helmut Haas, Thomas Spangenberg
After more than 40 years of use, Praziquantel (PZQ) still remains the drug of choice for the treatment of intestinal and urogenital schistosomiasis. Its anti-parasitic activity resides primarily in the (R)-enantiomer. Hitherto neither the molecular target nor the pharmacokinetic-pharmacodynamic relationship have been fully elucidated. Here we investigated the efficacy and pharmacokinetics of PZQ in the Schistosoma mansoni mouse model to determine the key factors that drive its efficacy. Dose-response studies with racemic PZQ with or without addition of an irreversible pan-cytochrome P450 (CYP) inhibitor, 1-aminobenzotriazole (ABT), were performed...
September 21, 2017: PLoS Neglected Tropical Diseases
https://www.readbyqxmd.com/read/28934155/anti-inflammatory-phenolic-metabolites-from-the-edible-fungus-phellinus-baumii-in-lps-stimulated-raw264-7-cells
#4
Seulah Lee, Dahae Lee, Tae Su Jang, Ki Sung Kang, Joo-Won Nam, Hae-Jeung Lee, Ki Hyun Kim
The edible fungus Phellinus baumii Pilat (Hymenochaetaceae) has been used in Korean traditional medicines for strengthening health and prolonging life. An extract of the fruiting bodies of P. baumii was subjected to bioassay-guided fractionation based on its anti-inflammatory effects in lipopolysaccharide (LPS)-stimulated RAW264.7 cells. The resulting fractions were chemically investigated, leading to isolation of three phenolic compounds (1-3), a sesquiterpene (4), two steroids (5-6), a fatty acid (7), and a cerebroside (8)...
September 21, 2017: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
https://www.readbyqxmd.com/read/28934012/liquid-chromatography-tandem-mass-spectrometry-method-for-simultaneous-quantification-of-azoxystrobin-and-its-metabolites-azoxystrobin-free-acid-and-2-hydroxybenzonitrile-in-greenhouse-grown-lettuce
#5
Maheswor Gautam, Inge S Fomsgaard
Lettuce is an important part of the diet in Europe. The permitted levels of pesticides in lettuce are strictly regulated and there is growing urge among food safety authorities to analyse pesticide metabolites as well. Azoxystrobin is one of pesticides that is frequently detected in lettuce. Although there are several analytical methods for the determination of azoxystrobin in lettuce, a sensitive method for the determination of its metabolites in lettuce is lacking. This study aimed at developing an extraction and LC-MS/MS method for the simultaneous determination of azoxystrobin, and its metabolites azoxystrobin free acid and 2-hydroxybenzonitrile in lettuce...
September 21, 2017: Food Additives & Contaminants. Part A, Chemistry, Analysis, Control, Exposure & Risk Assessment
https://www.readbyqxmd.com/read/28933832/detoxification-of-atrazine-by-low-molecular-weight-thiols-in-alfalfa-medicago-sativa
#6
Jing Jing Zhang, Jiang-Yan Xu, Feng Fan Lu, She Feng Jin, Hong Yang
Low molecular weight (LMW) thiols in higher plants are a group of sulfur-rich non-protein compounds and play primary and multiple roles in cellular redox homeostasis, enzyme activities, and xenobiotics detoxification. This study focused on identifying thiols-related protein genes from the legume alfalfa exposed to the herbicide atrazine (ATZ) residues in environment. Using high-throughput RNA-sequencing, a set of ATZ-responsive thiols-related protein genes highly up-regulated and differentially expressed in alfalfa were identified...
September 21, 2017: Chemical Research in Toxicology
https://www.readbyqxmd.com/read/28933337/the-polymorphism-of-cyp2d6-affects-the-pharmacokinetics-and-dose-escalation-of-paroxetine-controlled-release-tablet-in-healthy-chinese-subjects%C3%A2
#7
Rui Chen, Kai Shen, Pei Hu
PURPOSE: This study evaluated the effects of CYP2D6 polymorphisms on the pharmacokinetics and dose escalation of controlled-release paroxetine over the dose range of 12.5 - 37.5 mg in healthy Chinese subjects. MATERIALS AND METHODS: This was a phase I, open-label, single-dose, three-period crossover study in which 12 healthy subjects received single oral doses of 12.5, 25, and 37.5 mg paroxetine controlled-release tablets with 10-day washout between doses. Serial venous blood samples were collected for 96 hours after study-drug administration and analyzed with LC-MS/MS...
September 21, 2017: International Journal of Clinical Pharmacology and Therapeutics
https://www.readbyqxmd.com/read/28933336/bioavailability-of-oxycodone-after-administration-of-a-new-prolonged-release-once-daily-tablet-formulation-in-healthy-subjects-in-comparison-to-an-established-twice-daily-tablet%C3%A2
#8
Bernhard Scheidel, Martina A Maritz, Yves J Gschwind, Kerstin Steigerwald, Volker Guth, Peter Kovacs, Helene Rey
OBJECTIVE: To evaluate and to compare the bioavailability, the influence of food intake on the bioavailability, and the safety and tolerability of a newly-developed oxycodone once-daily (OOD) prolonged-release tablet with an established oxycodone twice-daily (OTD) prolonged-release tablet after single-dose administration under fasting or fed conditions as well as after multiple-dose administration. MATERIALS AND METHODS: Three single-center, open-label, randomized, balanced, two-treatment, two-period, two-sequence crossover studies were conducted...
September 21, 2017: International Journal of Clinical Pharmacology and Therapeutics
https://www.readbyqxmd.com/read/28932906/safety-study-and-therapeutic-drug-monitoring-of-the-oral-tablet-formulation-of-posaconazole-in-patients-with-haematological-malignancies
#9
C Boglione-Kerrien, S Picard, C Tron, S Nimubona, J-P Gangneux, S Lalanne, F Lemaitre, E Bellissant, M-C Verdier, A Petitcollin
PURPOSE: Posaconazole is a triazole antifungal widely used for prophylaxis of invasive fungal disease (IFI). Posaconazole tablets allow reaching higher plasma levels than the oral suspension, but safety data with this formulation in real life are scarce. This study aimed at evaluating the safety profile, the pharmacokinetic variability, and the concentration-toxicity relationship of posaconazole tablets in patients with haematological malignancies. METHODS: Sixty neutropenic patients treated with posaconazole tablets for prophylaxis of IFI were prospectively included in the study...
September 20, 2017: Journal of Cancer Research and Clinical Oncology
https://www.readbyqxmd.com/read/28932706/global-proteomics-revealed-klebsiella-pneumoniae-induced-autophagy-and-oxidative-stress-in-caenorhabditis-elegans-by-inhibiting-pi3k-akt-mtor-pathway-during-infection
#10
Arumugam Kamaladevi, Krishnaswamy Balamurugan
The enterobacterium, Klebsiella pneumoniae invades the intestinal epithelium of humans by interfering with multiple host cell response. To uncover a system-level overview of host response during infection, we analyzed the global dynamics of protein profiling in Caenorhabditis elegans using quantitative proteomics approach. Comparison of protein samples of nematodes exposed to K. pneumoniae for 12, 24, and 36 h by 2DE revealed several changes in host proteome. A total of 266 host-encoded proteins were identified by 2DE MALDI-MS/MS and LC-MS/MS and the interacting partners of the identified proteins were predicted by STRING 10...
2017: Frontiers in Cellular and Infection Microbiology
https://www.readbyqxmd.com/read/28930667/phenylpropanoid-profiling-reveals-a-class-of-hydroxycinnamoyl-glucaric-acid-conjugates-in-isatis-tinctoria-leaves
#11
Thi-Kieu-Oanh Nguyen, Arash Jamali, Eric Grand, Kris Morreel, Paulo Marcelo, Eric Gontier, Rebecca Dauwe
The brassicaceous herb, Isatis tinctoria, is an ancient medicinal plant whose rosette leaf extracts have anti-inflammatory and anti-allergic activity. Brassicaceae are known to accumulate a variety of phenylpropanoids in their rosette leaves acting as antioxidants and a UV-B shield, and these compounds often have pharmacological potential. Nevertheless, knowledge about the phenylpropanoid content of I. tinctoria leaves remains limited to the characterization of a number of flavonoids. In this research, we profiled the methanol extracts of I...
September 17, 2017: Phytochemistry
https://www.readbyqxmd.com/read/28930578/identification-of-bioactive-glucose-lowering-compounds-of-methanolic-extract-of-hodgsonia-heteroclita-fruit-pulp
#12
Talambedu Usha, Arvind Kumar Goyal, Derhasat Narzary, Lokesh Prakash, Gulshan Wadhwa, Dinesh Babu, Divya Shanmugarajan, Sushil Kumar Middha
We have investigated the anti-oxidative and glucose-lowering effects of 70% methanolic extract of H. heteroclita fruit pulp (MHE). Anti-oxidative property of MHE was assessed by free radical scavenging assays and compound level screening by LC-MS profiling. In silico analysis and in vivo preclinical validation were also performed using molecular docking and alloxan-induced diabetic model, respectively. MHE showed high anti-oxidant activity in DPPH radical scavenging assay with an IC50 of 0.37 μg/mL. The LC-MS profile of MHE substantiated the presence of p-hydroxy acids including benzoic, salicylic, p-coumaric, o-coumaric, caffeic, protocatechuic, gentisic, 2,4-dihydroxybenzoic, gallic, vanillic, syringic, and ferulic acids...
January 1, 2018: Frontiers in Bioscience (Landmark Edition)
https://www.readbyqxmd.com/read/28930563/mass-spectrometry-based-proteomic-analysis-of-the-dna-damage-response
#13
Matthew P Stokes, Yiying Zhu, Charles L Farnsworth
In response to DNA damage, cells have evolved mechanisms to halt cell cycle progression, activate repair, or initiate apoptosis. These DNA damage response (DDR) pathways are critical for cellular survival in response to genomic insult, and play important roles in growth, development, and disease. Historically, mediators of DNA damage response signaling have been studied one or a few proteins at a time. Advances in mass spectrometry instrumentation and enrichment methods now allow for more global analysis of the DDR in cells and tissues...
January 1, 2018: Frontiers in Bioscience (Landmark Edition)
https://www.readbyqxmd.com/read/28929657/-determination-of-five-naphthaquinones-in-arnebia-euchroma-by-quantitative-analysis-multi-components-with-single-marker
#14
Wen-Wen Zhao, Zhi-Min Wu, Xia Wu, Hai-Yu Zhao, Xiao-Qing Chen
This study is to determine five naphthaquinones (acetylshikonin, β-acetoxyisovalerylalkannin, isobutylshikonin, β,β'-dimethylacrylalkannin,α-methyl-n-butylshikonin) by quantitative analysis of multi-components with a single marker (QAMS). β,β'-Dimethylacrylalkannin was selected as the internal reference substance, and the relative correlation factors (RCFs) of acetylshikonin, β-acetoxyisovalerylalkannin, isobutylshikonin and α-methyl-n-butylshikonin were calculated. Then the ruggedness of relative correction factors was tested on different instruments and columns...
October 2016: Zhongguo Zhong Yao za Zhi, Zhongguo Zhongyao Zazhi, China Journal of Chinese Materia Medica
https://www.readbyqxmd.com/read/28929655/-a-semimicroquality-evaluation-method-on-panax-notoginseng-and-its-application-in-analysis-of-continuous-cropping-obstacles-research-samples
#15
Yi Cao, Chao-Qun Wang, Feng Xu, Xiu-Hong Jia, Guang-Xue Liu, Sheng-Chao Yang, Guang-Qiang Long, Zhong-Jian Chen, Fu-Zhou Wei, Shao-Zhou Yang, Kozo Fukuda, Xuan Wang, Shao-Qing Cai
Panax notoginseng is a commonly used traditional Chinese medicine with blood activating effect while has continuous cropping obstacle problem in planting process. In present study, a semimicroextraction method with water-saturated n-butanol on 0.1 g notoginseng sample was established with good repeatability (RSD<2.5%) and 9.6%-20.6% higher extraction efficiency of seven saponins than the conventional method. A total of 16 characteristic peaks were identified by LC-MS-IT-TOF, including eight 20(S)-protopanaxatriol (PPT) type saponins and eight 20(S)-protopanaxadiol (PPD) type saponins...
October 2016: Zhongguo Zhong Yao za Zhi, Zhongguo Zhongyao Zazhi, China Journal of Chinese Materia Medica
https://www.readbyqxmd.com/read/28929443/short-term-fasting-alters-pharmacokinetics-of-cytochrome-p450-probe-drugs-does-protein-binding-play-a-role
#16
Laureen A Lammers, Roos Achterbergh, Johannes A Romijn, Ron A A Mathôt
BACKGROUND AND OBJECTIVES: Short-term fasting differentially alters cytochrome P450 (CYP) mediated drug metabolism. This has been established by using CYP-enzyme selective probe drugs. However, the observed effects of fasting on the pharmacokinetics of these probe drugs may also include the effects of altered plasma protein binding of these drugs. Therefore, we studied the effect of short-term fasting on protein binding of five commonly used probe drugs [caffeine (CYP1A2), metoprolol (CYP2D6), midazolam (CYP3A4), omeprazole (CYP2C19) and S-warfarin (CYP2C9)]...
September 19, 2017: European Journal of Drug Metabolism and Pharmacokinetics
https://www.readbyqxmd.com/read/28928759/identification-of-biomarkers-for-defense-response-to-plasmopara-viticola-in-a-resistant-grape-variety
#17
Giulia Chitarrini, Evelyn Soini, Samantha Riccadonna, Pietro Franceschi, Luca Zulini, Domenico Masuero, Antonella Vecchione, Marco Stefanini, Gabriele Di Gaspero, Fulvio Mattivi, Urska Vrhovsek
Downy mildew (Plasmopara viticola) is one of the most destructive diseases of the cultivated species Vitis vinifera. The use of resistant varieties, originally derived from backcrosses of North American Vitis spp., is a promising solution to reduce disease damage in the vineyards. To shed light on the type and the timing of pathogen-triggered resistance, this work aimed at discovering biomarkers for the defense response in the resistant variety Bianca, using leaf discs after inoculation with a suspension of P...
2017: Frontiers in Plant Science
https://www.readbyqxmd.com/read/28928659/brain-pharmacokinetics-and-the-pharmacological-effects-on-striatal-neurotransmitter-levels-of-pueraria-lobata-isoflavonoids-in-rat
#18
Bingxin Xiao, Zengxian Sun, Fangrui Cao, Lisha Wang, Yonghong Liao, Xinmin Liu, Ruile Pan, Qi Chang
Isoflavonoids are putatively active components of Pueraria lobata and has been demonstrated prominent neuro-protection effect against cerebrovascular disorders, hypertension or Parkinson's disease (PD). However, the molecular basis for the beneficial effect of Pueraria lobata on nervous systems has not been well revealed. The present study aims to assess striatum exposure to main active isoflavonoids and changes of striatal extracellular neurotransmitters levels in rat brain after intravenous administration of Pueraria lobata isoflavonoids extracts (PLF), to further elucidate its' substantial bases for neuro activities...
2017: Frontiers in Pharmacology
https://www.readbyqxmd.com/read/28928529/antioxidant-properties-and-phenolic-profile-characterization-by-lc-ms-ms-of-selected-tunisian-pomegranate-peels
#19
Mouna Abid, Héla Yaich, Salma Cheikhrouhou, Ibtihel Khemakhem, Mohamed Bouaziz, Hamadi Attia, M A Ayadi
Antioxidant contents and activities of different extracts from four Tunisian pomegranate peels, locally called "Acide", "Gabsi", "Nebli" and "Tounsi", were studied. Peels samples were extracted with three solvents (water, ethanol and acetone). For each extract, the total phenol contents and antioxidant activity were evaluated. The highest values of polyphenol, tannins, flavonoids and anthocyanins were recorded in the acetone extract of Acide ecotype with 304.6 mg gallic acid equivalent/g; 292.23 mg gallic acid equivalent/g; 15...
August 2017: Journal of Food Science and Technology
https://www.readbyqxmd.com/read/28927937/evaluation-of-intensity-drift-correction-strategies-using-metabodrift-a-normalization-tool-for-multi-batch-metabolomics-data
#20
Chanisa Thonusin, Heidi B IglayReger, Tanu Soni, Amy E Rothberg, Charles F Burant, Charles R Evans
In recent years, mass spectrometry-based metabolomics has increasingly been applied to large-scale epidemiological studies of human subjects. However, the successful use of metabolomics in this context is subject to the challenge of detecting biologically significant effects despite substantial intensity drift that often occurs when data are acquired over a long period or in multiple batches. Numerous computational strategies and software tools have been developed to aid in correcting for intensity drift in metabolomics data, but most of these techniques are implemented using command-line driven software and custom scripts which are not accessible to all end users of metabolomics data...
September 9, 2017: Journal of Chromatography. A
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"