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Thankan Jayasekharan, Shyam L Gupta, Vikas Dhiman
The intrinsic binding ability of seven natural peptides (oxytocin, arg8 -vasopressin, bradykinin, angiotensin-I, substance-P, somatostatin, and neurotensin) with copper in two different oxidation states (CuI/II ) derived from different Cu+/2+ precursor sources have been investigated for their charge dependent binding characteristics. The peptide-CuI/II complexes, [M - (n-1)H + nCuI ] and [M - (2n-1)H + nCuII ] are prepared/generated by the reaction of peptides with CuI solution/Cu-target and CuSO4 solution, and are analyzed using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOFMS)...
January 15, 2018: Journal of Mass Spectrometry: JMS
Megan R Showalter, Eric B Nonnecke, A L Linderholm, Tomas Cajka, Michael R Sa, Bo Lönnerdal, Nicholas J Kenyon, Oliver Fiehn
Obesity and accompanying metabolic disease is negatively correlated with lung health yet the exact mechanisms by which obesity affects the lung are not well characterized. Since obesity is associated with lung diseases as chronic bronchitis and asthma, we designed a series of experiments to measure changes in lung metabolism in mice fed obesogenic diets. Mice were fed either control or high fat/sugar diet (45%kcal fat/17%kcal sucrose), or very high fat diet (60%kcal fat/7% sucrose) for 150 days. We performed untargeted metabolomics by GC-TOFMS and HILIC-QTOFMS and lipidomics by RPLC-QTOFMS to reveal global changes in lung metabolism resulting from obesity and diet composition...
2018: PloS One
Jingcheng Wang, Yuanlong Hou, Zhiying Jia, Xie Xie, Jiajian Liu, Yani Kang, Xin Wang, Xiaoyan Wang, Wei Jia
Different components of P. ginseng have different properties and medicinal effects. Metabonomics was a perspective approach to analyze global endogenous metabolites response to physiological and pathological processe. In this study, untargeted -metabonomics method using GC/TOFMS combined with multivariate statistical techniques was applied to compare entire metabolite differences and the anti-stress variations among four components of P. ginseng, total ginsenosides (TG), panaxadiol (PD), panaxatriol (PT) and ginseng polysaccharide (PS), in Sprague Dawley rats...
January 5, 2018: Journal of Proteome Research
Daguang Wang, Wei Li, Qi Zou, Lei Yin, Yechao Du, Jingkai Gu, Jian Suo
Objective: This study was aimed to investigate serum metabolites in gastric cancer (GC) patients and their relationships with the prognosis of GC in order to find potential specific serum biomarkers for GC. Methods: Blood samples of 125 GC patients of unifocal GC at initial stage and 38 healthy people recruited in our hospital from September 2008 to August 2009 were analyzed by using high performance liquid chromatography coupled with electrospray ionization/quadrupole-time-of-flight mass spectrometry (HPLCESI/Q-TOFMS)...
December 15, 2017: Oncotarget
In-Young Chung, Yu-Mi Park, Hyun-Jeoung Lee, Hyuk Kim, Dong-Hoon Kim, Il-Gyu Kim, Sang-Min Kim, Young-Sun Do, Kwang-Seol Seok, Jung-Hwan Kwon
It is thought that there are many unregulated anthropogenic chemicals in the environment. For risk assessment of chemicals, it is essential to estimate the predicted environmental concentrations. As an effort of identifying residual organic contaminants in air and water in Korea, nontarget screening using two-dimensional gas chromatography time-of-flight mass spectrometry (GC×GC-TOFMS) was conducted at 10 sites using polyurethane foam passive air sampler and at 6 sites using polydimethyl siloxane (PDMS) passive water sampler in three different seasons in 2014...
December 2017: Journal of Environmental Sciences (China)
Zhisen Liang, Shudi Zhang, Xiaoping Li, Tongtong Wang, Yaping Huang, Wei Hang, Zhilin Yang, Jianfeng Li, Zhongqun Tian
Spectroscopic methods with nanoscale lateral resolution are becoming essential in the fields of physics, chemistry, geology, biology, and materials science. However, the lateral resolution of laser-based mass spectrometry imaging (MSI) techniques has so far been limited to the microscale. This report presents the development of tip-enhanced ablation and ionization time-of-flight mass spectrometry (TEAI-TOFMS), using a shell-isolated apertureless silver tip. The TEAI-TOFMS results indicate the capability and reproducibility of the system for generating nanosized craters and for acquiring the corresponding mass spectral signals...
December 2017: Science Advances
Brian J Malys, Michelle L Piotrowski, Kevin G Owens
Frustrated by worse than expected error for both peak area and time-of-flight (TOF) in matrix assisted laser desorption ionization (MALDI) experiments using samples prepared by electrospray deposition, it was finally determined that there was a correlation between sample location on the target plate and the measured TOF/peak area. Variations in both TOF and peak area were found to be due to small differences in the initial position of ions formed in the source region of the TOF mass spectrometer. These differences arise largely from misalignment of the instrument sample stage, with a smaller contribution arising from the non-ideal shape of the target plates used...
December 7, 2017: Journal of the American Society for Mass Spectrometry
Sayaka Iida, Yuki Ohkubo, Yorihiro Yamamoto, Akio Fujisawa
Uric acid quenches singlet oxygen physically or reacts with it, but the oxidation product has not been previously characterized. The present study determined that the product is parabanic acid, which was confirmed by LC/TOFMS analysis. Parabanic acid was stable at acidic pH (<5.0), but hydrolyzed to oxaluric acid at neutral or alkaline pH. The total yields of parabanic acid and oxaluric acid based on consumed uric acid were ~100% in clean singlet oxygen production systems such as UVA irradiation of Rose Bengal and thermal decomposition of 3-(1,4-dihydro-1,4-epidioxy-4-methyl-1-naphthyl)propionic acid...
November 2017: Journal of Clinical Biochemistry and Nutrition
Huijuan Wang, Hailong Zhang, Ling Yao, Longzhen Cui, Lei Zhang, Biao Gao, Wen Liu, Dongdong Wu, Mingliang Chen, Xue Li, Ailing Ji, Yanzhang Li
BACKGROUND: Type 2 diabetes mellitus (T2DM) is a huge burden in China. The Chinese patients with T2DM have several special clinical characteristics. Metabolomics studies predominantly have identified several distinguishing metabolites associated with T2DM in Western ancestry population. However, few previous metabolomics studies were conducted in Chinese populations. METHODS: We performed untargeted serum metabolic profiling between 30 T2DM patients and 30 healthy controls based on GC/TOFMS...
November 29, 2017: Clinica Chimica Acta; International Journal of Clinical Chemistry
Lee Cheng Phua, Shixu Goh, David Wai Meng Tai, Wei Qiang Leow, Syed Muhammad Fahmy Alkaff, Chung Yip Chan, Juinn Huar Kam, Tony Kiat Hon Lim, Eric Chun Yong Chan
PURPOSE: Resistance to gemcitabine remains a key challenge in the treatment of pancreatic ductal adenocarcinoma (PDAC), necessitating the constant search for effective strategies for a priori prediction of clinical outcome. While the existing studies focused on aberration of drug disposition genes and proteins as molecular predictors of gemcitabine treatment outcomes, the metabolic aberration associated with chemoresistance in clinical PDAC has been neglected. This exploratory study investigated the potential role of tissue metabolomics in characterizing the clinical treatment outcome of gemcitabine therapy...
December 1, 2017: Cancer Chemotherapy and Pharmacology
Shoji Yamada, Nobuhiko Kamada, Takeru Amiya, Nobuhiro Nakamoto, Toshiaki Nakaoka, Masaki Kimura, Yoshimasa Saito, Chieko Ejima, Takanori Kanai, Hidetsugu Saito
BACKGROUND: The gut microbiota plays crucial roles in the development of non-alcoholic steatohepatitis (NASH). However, the precise mechanisms by which alterations of the gut microbiota and its metabolism contributing to the pathogenesis of NASH are not yet fully elucidated. METHODS: Mice were fed with a recently reported new class of high-fat diet (HFD), steatohepatitis-inducing HFD (STHD)-01 for 9 weeks. The composition of the gut microbiota was analyzed by T-RFLP...
November 29, 2017: BMC Gastroenterology
Karine P Nicolli, Aline C T Biasoto, Érica A Souza-Silva, Celito C Guerra, Henrique P Dos Santos, Juliane E Welke, Cláudia A Zini
For the first time, the influence of different vine management was evaluated in relation to volatile profile and sensory perception through GC×GC/TOFMS, QDA, GC-FID, GC/MS, and GC-O. GC×GC/TOFMS analyses and QDA have shown that a larger spacing between vine rows (2 rather than 1m), attachment of shoots upwards, and irrigation did not result in wine improvement. Conversely, wines elaborated with grapes from a vine with a lower bud load (20 per plant; sample M1) stood out among the other procedures, rendering the most promising wine aroma...
March 15, 2018: Food Chemistry
Shan Yin, Pan Guo, Dafu Hai, Li Xu, Jiale Shu, Wenjin Zhang, Muhammad Idrees Khan, Irwin J Kurland, Yunping Qiu, Yumin Liu
In this paper, an optimized method based on gas chromatography/time-of-flight mass spectrometry (GC-TOFMS) platform has been developed for the analysis of gut microbial-host related co-metabolites in fecal samples. The optimization was performed with proportion of chloroform (C), methanol (M) and water (W) for the extraction of specific metabolic pathways of interest. Loading Bi-plots from the PLS regression model revealed that high concentration of chloroform emphasized the extraction of short chain fatty acids and TCA intermediates, while the higher concentration of methanol emphasized indole and phenyl derivatives...
December 1, 2017: Analytica Chimica Acta
Hui Jiang, Xiu-Juan Qin, Wei-Ping Li, Rong Ma, Ting Wang, Zhu-Qing Li
Liver fibrosis is a common stage in the majority of chronic liver diseases, regardless of the etiology, and its progression may lead to hepatic cirrhosis or hepatocellular carcinoma. Metabolomics, a powerful approach in systems biology, is a discipline used to qualitatively and quantitatively analyze the small molecule metabolites of cells at specific times and under certain conditions. The present study aimed to investigate serum metabolic changes following Shu Gan Jian Pi formula (SGJPF) treatment of carbon tetrachloride (CCl4)‑induced liver fibrosis in rats using gas chromatography‑time of flight mass spectrometry (GC‑TOFMS)...
October 2017: Molecular Medicine Reports
Marianna Raczyk, Aleksander Siger, Elżbieta Radziejewska-Kubzdela, Katarzyna Ratusz, Magdalena Rudzińska
BACKGROUND: Pumpkin seed oil is valuable oil for its distinctive taste and aroma, as well as supposed health- promoting properties. The aim of this study was to investigate how roasting pumpkin seeds influences the physicochemical properties of cold-pressed oils. METHODS: The fatty acid composition, content of phytosterols, carotenoids and tocopherols, oxidative stability and colour were determined in oils after cold pressing and storage for 3 months using GC-FID, GCxGC-ToFMS, HPLC, Rancimat and spectrophotometric methods...
July 2017: Acta Scientiarum Polonorum. Technologia Alimentaria
Benjamin Savareear, Michał Brokl, Chris Wright, Jean-Francois Focant
A thermal desorption comprehensive two-dimensional gas chromatography coupled to time-of-flight mass spectrometry (TD-GC×GC-TOFMS) method has been developed for the analysis of mainstream tobacco smoke (MTS) vapour phase (VP). The selection process of the sample introduction approach involved comparing the results obtained from three different approaches: a) use of gas sampling bag followed by SPME (Tedlar(®)-SPME), b) gas sampling bag followed by TD (Tedlar(®)-TD), and c) sampling directly on TD sorbents (Direct-TD)...
October 6, 2017: Journal of Chromatography. A
Claudia Kruth, Hendryk Czech, Martin Sklorz, Johannes Passig, Sven Ehlert, Achille Cappiello, Ralf Zimmermann
Direct infusion resonance-enhanced multiphoton ionization (DI-REMPI) was performed on liquid samples, which were introduced to the ion source via a direct liquid interface, to enable the investigation of dissolved aromatic compounds. Desolvation and nebulization of the samples were supported by a heated repeller using flow rates in the upper nL min(-1) range. The obtained mass spectra of five pure polycyclic aromatic hydrocarbons as well as complex petroleum samples revealed predominantly molecular ions without evidence of solvent or dopant effects as observed in atmospheric pressure photoionization (APPI) and laser ionization (APLI) with limits of detection in the lower pmol range...
September 29, 2017: Analytical Chemistry
Paul J Jones, Blake Riser, Jingsong Zhang
Thermal decomposition of t-butyl hydroperoxide and di-t-butyl peroxide was investigated using flash pyrolysis (in a short reaction time of <100 μs) and vacuum-ultraviolet (λ = 118.2 nm) single-photon ionization time-of-flight mass spectrometry (VUV-SPI-TOFMS) at temperatures up to 1120 K and quantum computational methods. Acetone and methyl radical were detected as the predominant products in the initial decomposition of di-t-butyl peroxide via O-O bond fission. In the initial dissociation of t-butyl hydroperoxide, acetone, methyl radical, isobutylene, and isobutylene oxide products were identified...
October 10, 2017: Journal of Physical Chemistry. A
Christiaan Rees, Alison Burklund, Pierre-Hugues Stefanuto, Joseph D Schwartzman, Jane E Hill
The identification of pathogen-specific volatile metabolic "fingerprints" could lead to the rapid identification of disease-causing organisms either directly from <i>ex vivo</i> patient bio-specimens or from <i>in vitro</i> cultures. In the present study, we have evaluated the volatile metabolites produced by 100 clinical isolates belonging to ten distinct pathogen groups that, in aggregate, account for 90 % of bloodstream infections, 90 % of urinary tract infections, and 80 % of infections encountered in the intensive care unit setting...
September 27, 2017: Journal of Breath Research
Kevin A Kovalchik, Matthew S MacLennan, Kerry M Peru, Chukwuemeka Ajaero, Dena W McMartin, John V Headley, David D Y Chen
RATIONALE: The characterization of naphthenic acid fraction compounds (NAFCs) in oil sands process affected water (OSPW) is of interest for both toxicology studies and regulatory reasons. Previous studies utilizing authentic standards have identified dicarboxylic naphthenic acids using two-dimensional gas chromatography hyphenated to time-of-flight mass spectrometry (GCxGC/TOFMS). The selective derivatization of hydroxyl groups has also recently aided in the characterization of oxy-NAFCs, and indirectly the characterization of dicarboxylic NAFCs...
September 25, 2017: Rapid Communications in Mass Spectrometry: RCM
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