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https://www.readbyqxmd.com/read/28531811/synthesis-of-novel-indole-derivatives-as-promising-dna-binding-agents-and-evaluation-of-antitumor-and-antitopoisomerase-i-activities
#1
Elizabeth Almeida Lafayette, Sinara Mônica Vitalino de Almeida, Renata Virginia Cavalcanti Santos, Jamerson Ferreira de Oliveira, Cezar Augusto da Cruz Amorim, Rosali Maria Ferreira da Silva, Maira Galdino da Rocha Pitta, Ivan da Rocha Pitta, Ricardo Olimpio de Moura, Luiz Bezerra de Carvalho Júnior, Moacyr Jesus Barreto de Melo Rêgo, Maria do Carmo Alves de Lima
Molecules bearing indole nucleus present diverse biological properties such as antitumor and anti-inflammatory activities that can be associated both to DNA and protein interactions. This study focused on the synthesis of new indole derivatives with thiazolidines and imidazolidine rings condensed as side chains as well as the evaluation of their ability to interact with the DNA and antitumor and topoisomerase inhibition activities. All derivatives were successfully synthesized and their structures were elucidated by mass spectrometry (MS), infrared (IR), spectroscopy (1)H NMR, (13)C NMR, COSY (1)H-(1)H and HSQC (1)H-(13)C...
May 4, 2017: European Journal of Medicinal Chemistry
https://www.readbyqxmd.com/read/28530406/comparative-evaluation-of-small-molecular-additives-and-their-effects-on-peptide-protein-identification
#2
Jing Gao, Shaoyun Zhong, Yanting Zhou, Han He, Shuying Peng, Zhenyun Zhu, Xing Liu, Jing Zheng, Bin Xu, Hu Zhou
Detergents and salts are widely used in lysis buffers to enhance protein extraction from biological samples, facilitating in-depth proteomic analysis. However, these detergents and salt additives must be efficiently removed from the digested samples prior to LC-MS/MS analysis to obtain high-quality mass spectra. Although filter-aided sample preparation (FASP), acetone precipitation (AP), followed by in-solution digestion, and strong cation exchange-based centrifugal proteomic reactors (CPRs) are commonly used for proteomic sample processing, little is known about their efficiencies at removing detergents and salt additives...
May 22, 2017: Analytical Chemistry
https://www.readbyqxmd.com/read/28529831/source-identification-of-western-oregon-douglas-fir-wood-cores-using-mass-spectrometry-and-random-forest-classification
#3
Kristen Finch, Edgard Espinoza, F Andrew Jones, Richard Cronn
PREMISE OF THE STUDY: We investigated whether wood metabolite profiles from direct analysis in real time (time-of-flight) mass spectrometry (DART-TOFMS) could be used to determine the geographic origin of Douglas-fir wood cores originating from two regions in western Oregon, USA. METHODS: Three annual ring mass spectra were obtained from 188 adult Douglas-fir trees, and these were analyzed using random forest models to determine whether samples could be classified to geographic origin, growth year, or growth year and geographic origin...
May 2017: Applications in Plant Sciences
https://www.readbyqxmd.com/read/28528194/analysis-of-peg-oligomers-in-black-gel-inks-discrimination-and-ink-dating
#4
Qiran Sun, Yiwen Luo, Ping Xiang, Xu Yang, Min Shen
Carbon-based black gel inks are common samples in forensic practice of questioned document examination in China, but there are few analytical methods for this type of ink. In this study, a liquid chromatography-.high resolution mass spectrometry (LC-HRMS) method was established for the analysis of PEG oligomers in carbon-based black gel ink entries. The coupled instruments achieve both the identification and quantification of PEG oligomers in ink entries with reproducible results. Twenty carbon-based black gel inks, whose Raman spectra appeared identical, were analyzed using the LC-HRMS method...
May 4, 2017: Forensic Science International
https://www.readbyqxmd.com/read/28527413/monochromatic-green-light-induces-an-aberrant-accumulation-of-geranylgeranyled-chlorophylls-in-plants
#5
Zuzana Materová, Roman Sobotka, Barbora Zdvihalová, Michal Oravec, Jakub Nezval, Václav Karlický, Daniel Vrábl, Michal Štroch, Vladimír Špunda
Light quality is an important environmental factor affecting the biosynthesis of photosynthetic pigments whose production seems to be affected not only quantitatively but also qualitatively. In this work, we set out to identify unusual pigment detected in leaves of barley (Hordeum vulgare L.) and explain its presence in plants grown under monochromatic green light (GL; 500-590 nm). The chromatographic analysis (HPLC-DAD) revealed that a peak belonging to this unknown pigment is eluted between chlorophyll (Chl) a and b...
May 6, 2017: Plant Physiology and Biochemistry: PPB
https://www.readbyqxmd.com/read/28525865/a-selective-naked-eye-chemosensor-derived-from-2-methoxybenzylamine-and-2-3-dihydroxybenzaldehyde-synthesis-spectral-characterization-and-electrochemistry-of-its-bis-bidentates-schiff-bases-metal-complexes
#6
Aggoun Djouhra, Ourari Ali, Ruiz-Rosas Ramiro, Morallon Emilia
A new colorimetric receptor HL, acting as a bidentate Schiff base ligand, has been synthesized by condensation of 2-methoxybenzylamine on 2,3-dihydroxybenzaldehyde in a methanolic solution. Interestingly, this chelating agent can selectively detect Cu(2+), Co(2+), Fe(2+) and Fe(3+) ions with a simple and an easy-to-make, well defined naked-eye visible color changes in two different solvents like acetonitrile and methanol. This bidentate ligand coordinates three metal ions of Co(II), Cu(II) and Fe(II) via nitrogen and oxygen atoms...
May 10, 2017: Spectrochimica Acta. Part A, Molecular and Biomolecular Spectroscopy
https://www.readbyqxmd.com/read/28524199/multiple-electron-capture-from-isolated-protein-poly-anions-in-collision-with-slow-highly-charged-ions
#7
A R Milosavljević, P Rousseau, A Domaracka, B A Huber, A Giuliani
Collisions of 375 keV Xe(25+) ions with trapped mass/charge selected poly-anions of the cytochrome C protein (∼12.5 kDa) were studied by coupling a linear quadrupole ion trap with low-energy ion beam facility. Tandem mass spectra were recorded for the protein precursor charge states ranging from -9 to -17. The present work reports the first study of slow highly charged ion collisions with poly-anions. A high signal to noise ratio allowed the study of the intensity of single and multiple electron removal by a projectile, as well as associated neutral losses, as a function of the target charge state...
May 19, 2017: Physical Chemistry Chemical Physics: PCCP
https://www.readbyqxmd.com/read/28523500/desi-mass-spectrometry-imaging-msi
#8
Emmanuelle Claude, Emrys A Jones, Steven D Pringle
Desorption Electrospray Ionization (DESI) mass spectrometry is a technique that allows chemical information to be obtained directly from a wide range of surfaces. Using a 2D stage, DESI can be implemented in an imaging mode whereby MS spectra are collected by rastering the spray across the whole surface. Here, we describe the implementation and optimization of DESI imaging for metabolites and lipids from tissue sections using oa-TOF mass spectrometers.
2017: Methods in Molecular Biology
https://www.readbyqxmd.com/read/28521980/sulphated-polysaccharide-isolated-from-sargassum-vulgare-characterization-and-hypolipidemic-effects
#9
Rihab Ben Abdallah Kolsi, Hichem Ben Salah, Neila Jardak, Rim Chaaben, Imed Jribi, Abdelfattah El Feki, Tarak Rebai, Kamel Jamoussi, Noureddine Allouche, Cristophe Blecker, Hafedh Belghith, Karima Belghith
A sulphated polysaccharide from brown algae Sargassum vulgare (SVSP) was extracted and examined with respect to chemical, structural characterization and hypolipidemic effects. SVSP consisted mainly of sulphate and total sugars with low levels of lipids and proteins. Its structure was studied by nuclear magnetic resonance (RMN), gas chromatography-mass spectrometry (GC-MS), infra-red spectroscopic, differential scanning calorimetry and X-ray diffraction analysis. Allowing us therefore to revealed that SVSP was composed of glucose, rhamnose, xylose, galactose, mannose and arabinose with XRD pattern that was typical for a semi-crystalline polymer and complexities of the spectra reflected its homogeneous structure...
August 15, 2017: Carbohydrate Polymers
https://www.readbyqxmd.com/read/28521505/orientation-and-conformation-of-osteocalcin-adsorbed-onto-calcium-phosphate-and-silica-surfaces
#10
Luisa A Scudeller, Selvi Srinivasan, Alexandre M Rossi, Patrick S Stayton, Gary P Drobny, David G Castner
Adsorption isotherms, circular dichroism (CD) spectroscopy, x-ray photoelectron spectroscopy (XPS), and time-of-flight secondary ion mass spectrometry (ToF-SIMS) were used to investigate the adsorption of human osteocalcin (hOC) and decarboxylated (i.e., Gla converted back to Glu) hOC (dhOC) onto various calcium phosphate surfaces as well as silica surfaces. The adsorption isotherms and XPS nitrogen signals were used to track the amount of adsorbed hOC and dhOC. The intensities of key ToF-SIMS amino acid fragments were used to assess changes in the structure of adsorbed hOC and dhOC...
May 18, 2017: Biointerphases
https://www.readbyqxmd.com/read/28520473/a-new-method-and-mass-spectrometric-instrument-for-extraterrestrial-microbial-life-detection-using-the-elemental-composition-analyses-of-martian-regolith-and-permafrost-ice
#11
G G Managadze, A A Safronova, K A Luchnikov, E A Vorobyova, N S Duxbury, P Wurz, N G Managadze, A E Chumikov, R Kh Khamizov
We propose a new technique for the detection of microorganisms by elemental composition analyses of a sample extracted from regolith, permafrost, and ice of extraterrestrial bodies. We also describe the design of the ABIMAS instrument, which consists of the onboard time-of-flight laser mass-reflectron (TOF LMR) and the sample preparation unit (SPU) for biomass extraction. This instrument was initially approved to fly on board the ExoMars 2020 lander mission. The instrument can be used to analyze the elemental composition of possible extraterrestrial microbial communities and compare it to that of terrestrial microorganisms...
May 2017: Astrobiology
https://www.readbyqxmd.com/read/28520403/integrated-strategy-for-unknown-ei-ms-identification-using-quality-control-calibration-curve-multivariate-analysis-ei-ms-spectral-database-and-retention-index-prediction
#12
Teruko Matsuo, Hiroshi Tsugawa, Hiromi Miyagawa, Eiichiro Fukusaki
Compound identification using unknown electron ionization (EI) mass spectra in gas chromatography coupled with mass spectrometry (GC-MS) is challenging in untargeted metabolomics, natural product chemistry, or exposome research. While the total count of EI-MS records included in publicly or commercially available databases is over 900,000, efficient use of this huge database has not been achieved in metabolomics. Therefore, we proposed a 'four-step' strategy for the identification of biologically significant metabolites using an integrated cheminformatics approach: (i) Quality control calibration curve to reduce background noise, (ii) variable selection by hypothesis testing in principal component analysis for the efficient selection of target peaks, (iii) searching the EI-MS spectral database, and (iv) retention index (RI) filtering in combination with RI predictions...
May 18, 2017: Analytical Chemistry
https://www.readbyqxmd.com/read/28518173/simultaneous-quantification-of-n-and-o-glycans-using-a-solid-phase-method
#13
Shuang Yang, Yingwei Hu, Lori Sokoll, Hui Zhang
Glycosylation has a pivotal role in a diverse range of biological activities, modulating the structure and function of proteins. Glycogens coupled to the nitrogen atom (N-linked) of asparagine side chains or to the oxygen atom (O-linked) of serine and threonine side chains represent the two major protein glycosylation forms. N-glycans can be released by glycosidases, whereas O-glycans are often cleaved by chemical reaction. However, it is challenging to combine these enzymatic and chemical reactions in order to analyze both N- and O-glycans...
June 2017: Nature Protocols
https://www.readbyqxmd.com/read/28517936/in-situ-hydrogel-conditioning-of-tissue-samples-to-enhance-the-drug-s-sensitivity-in-ambient-mass-spectrometry-imaging
#14
Xiaowei Song, Zhigang Luo, Xin Li, Tiegang Li, Zhonghua Wang, Chenglong Sun, Luojiao Huang, Ping Xie, Xiaoyu Liu, Jiuming He, Zeper Abliz
Ion suppression from the tissue matrix has a severe effect on the mass spectrometry imaging (MSI) of drugs. This problem hinders further applications of MSI in preclinical drug research and development. In this study, an in situ hydrogel conditioning method was developed to enhance the sensitivity of air-flow-assisted desorption electrospray ionization (AFADESI)-MSI. Instead of the traditional wash-up or digestion treatment in solvent, this method used a solid phase hydrogel to "wash" tissue sections. It was demonstrated that this in situ hydrogel conditioning method improve the drug signal by as much as 2- to 25-folds in MSI, especially for hydrophobic compounds...
May 18, 2017: Analytical Chemistry
https://www.readbyqxmd.com/read/28516769/identification-of-rotundone-as-a-potent-odor-active-compound-of-several-kinds-of-fruits
#15
Akira Nakanishi, Yusuke Fukushima, Norio Miyazawa, Keisuke Yoshikawa, Tomoko Maeda, Yoshiko Kurobayashi
An investigation of the aromas of grapefruit, orange, apple, and mango revealed the presence of an odor-active compound that gave off a strong woody odor when assessed by gas chromatography-olfactometry. We isolated the compound from a high-boiling fraction of an orange essential oil, and subsequent nuclear magnetic resonance analyses of the isolated compound identified it as rotundone. Mass spectra and retention indices obtained from aroma concentrates of grapefruit, apple, and mango were identical to those of rotundone, which was therefore determined to be the common woody compound in these fruits...
May 24, 2017: Journal of Agricultural and Food Chemistry
https://www.readbyqxmd.com/read/28514852/separated-immobilization-of-incompatible-enzymes-on-polymer-substrate-via-visible-light-induced-living-photografting-polymerization
#16
Xing Zhu, Bin He, Changwen Zhao, Yuhong Ma, Wantai Yang
The use of the mixed catalytic system with several enzymes can provide multiple benefits in terms of the costs, simplification of a multi-steps reaction, and the effectiveness of the complex chemical reactions. Although study of different enzymes co-immobilization system has attracted increasing attention in recent years, separately immobilizing enzymes which can not coexist on one support is still one of the great challenges. In this paper, a simple and effective strategy was introduced to separately encapsulate incompatible trypsin and transglutaminase (TGase) into different poly(ethylene glycol) (PEG) network layer grafted on low-density polyethylene (LDPE) film via visible light induced living photografting polymerization...
May 17, 2017: Langmuir: the ACS Journal of Surfaces and Colloids
https://www.readbyqxmd.com/read/28514166/a-web-service-framework-for-interactive-analysis-of-metabolomics-data
#17
Yaroslav Lyutvinskiy, Jeramie D Watrous, Mohit Jain, Roland Nilsson
Analyzing mass spectrometry-based metabolomics data presents a major challenge to metabolism researchers, as it requires downloading and processing large data volumes through complex "pipelines", even in cases where only a single metabolite or peak is of interest. This presents a significant hurdle for data sharing, reanalysis, or meta-analysis of existing data sets, whether locally stored or available from public repositories. Here we introduce mzAccess, a software system that provides interactive, online access to primary mass spectrometry data in real-time via a Web service protocol, circumventing the need for bulk data processing...
May 17, 2017: Analytical Chemistry
https://www.readbyqxmd.com/read/28513645/electrode-potential-dependent-desolvation-and-resolvation-of-germanium-100-in-contact-with-aqueous-perchlorate-electrolytes
#18
Fang Niu, Rainer Schulz, Arcesio Castañeda Medina, Rochus Schmid, Andreas Erbe
The electrode potential dependence of the hydration layer on an n-Ge(100) surface was studied by a combination of in situ and operando electrochemical attenuated total reflection infrared (ATR-IR) spectroscopy and real space density functional theory (DFT) calculations. Constant-potential DFT calculations were coupled to a modified generalised Poisson-Boltzmann ion distribution model and applied within an ab initio molecular dynamics (AIMD) scheme. As a result, potential-dependent vibrational spectra of surface species and surface water were obtained, both experimentally and by simulations...
May 17, 2017: Physical Chemistry Chemical Physics: PCCP
https://www.readbyqxmd.com/read/28513289/detection-of-meat-species-adulteration-using-high-resolution-mass-spectrometry-and-a-proteogenomics-strategy
#19
Alberto Ruiz Orduna, Erik Husby, Charles T Yang, Dipankar Ghosh, Francis Beaudry
Due to the internationalization of food production and distribution, there has been a significant increase of food fraud in recent years. Food fraud can have serious health implications, and occurs when food manufacturers implement unethical practices such as making false label claims as well as using additives and fillers within their products to increase profitability. This has been a serious concern. Meat adulteration was examined using a well-defined proteogenomic annotation, carefully selected surrogate tryptic peptides and high-resolution mass spectrometry...
May 17, 2017: Food Additives & Contaminants. Part A, Chemistry, Analysis, Control, Exposure & Risk Assessment
https://www.readbyqxmd.com/read/28513110/separation-and-purification-of-two-minor-typical-diarrhetic-shellfish-poisoning-toxins-from-harmful-marine-microalgae-via-combined-liquid-chromatography-with-mass-spectrometric-detection
#20
Junhui Chen, Yanlong Wang, Lei Pan, Huihui Shen, Dan Fu, Boqiang Fu, Chengjun Sun, Li Zheng
A novel method was developed for the purification of two typical diarrhetic shellfish poisoning toxins from toxin-producing marine microalgae using macroporous resin, high-speed counter-current chromatography-mass spectrometry, and semi-preparative high-performance liquid chromatography-mass spectrometry (HPLC-MS). Analytical HPLC-MS was used for identification and purity analysis of okadaic acid and dinophysistoxin-1 because they exhibit no visible or ultraviolet absorption. First, four kinds of macroporous resins were investigated, and HP-20 macroporous resin was selected for the pre-enrichment and cleanup of the two target toxins...
May 17, 2017: Journal of Separation Science
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