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Journal of Mass Spectrometry: JMS

Nóra Gampe, András Darcsi, Andrea Nagyné Nedves, Imre Boldizsár, László Kursinszki, Szabolcs Béni
Ononis arvensis L. can be found overall in Europe and is used to treat infections of the urinary tract and skin diseases in ethnopharmacology. Flavonoids, hydroxycinnamic acids, oxycoumarin scopoletin and scopolin, phytosterols, lectins and some selected isoflavonoids were identified in O. arvensis till date; however, there is a lack of the detailed investigation of the isoflavonoid profile of the plant. With the application of high-resolution tandem mass spectrometry, the fragmentation patterns of isoflavonoid derivatives found in O...
November 8, 2018: Journal of Mass Spectrometry: JMS
Te-Yu Chen, Min-Li Wu, Yu-Chie Chen
Microfluidics can be used to handle relatively small volumes of samples and to conduct reactions in microliter-sized volumes. Electrospray ionization (ESI) can couple microfluidics with mass spectrometry (MS) to monitor chemical reactions on-line. However, fabricating microfluidic chips is time-consuming. We herein propose the use of a micro-reactor that is sustained by two capillaries and an ultrasonicator. The inlets of the capillaries were individually immersed to two different sample vials that were subjected to the ultrasonicator...
November 8, 2018: Journal of Mass Spectrometry: JMS
Zhen Liu, Yunlong Shao, Guizhen Zhu, Xiayan Wang, Yunfeng Chai, Lin Wang
Chromones were measured by using electrospray ionization mass spectrometry in negative mode. Interestingly, in addition to the deprotonated ion ([M - H]- ), unexpected [M + 17]- and [M + 31]- ions were observed in high intensity when water and methanol were used as the solvent. Chromones with different substitutes were tested. Compared with the deprotonated ion, [M + 17]- and [M + 31]- ions were observed with higher abundances when the C-3 site of chromones was substituted by electron withdrawing groups. Based on high performance liquid chromatography-mass spectrometry (LC-MS), deuterium labeling and collisional induced dissociation experiments, a covalent gas-phase nucleophilic addition reaction between chromone and water, and the formation of a non-covalent complex between chromone and methanol were proposed as the mechanism for the observed [M+17]- and [M + 31]- ions, respectively...
October 31, 2018: Journal of Mass Spectrometry: JMS
Aikaterini Kondyli, Wolfgang Schrader
The continuous development in analytical instrumentation has brought the newly developed Orbitrap based GC-MS instrument into the forefront for the analysis of complex mixtures such as crude oil. Traditional instrumentation usually requires a choice to be made between mass resolving power or an efficient chromatographic separation which ideally enables the distinction of structural isomers which is not possible by mass spectrometry alone. Now, these features can be combined, thus enabling a deeper understanding of the constituents of volatile samples on a molecular level...
October 30, 2018: Journal of Mass Spectrometry: JMS
Herbert J Dias, Manon Baguenard, Eduardo J Crevelin, Vinicius Palaretti, Paul J Gates, Ricardo Vessecchi, Antônio E M Crotti
We have investigated gas-phase fragmentation reactions of protonated benzofuran neolignans (BNs) and dihydrobenzofuran neolignans (DBNs) by accurate-mass electrospray ionization tandem and multiple-stage (MSn ) mass spectrometry combined with thermochemical data estimated by Computational Chemistry. Most of the protonated compounds fragment into product ions B ([M+H-MeOH]+ ), C ([B-MeOH]+ ), D ([C-CO]+ ), and E ([D-CO]+ ) upon collision-induced dissociation (CID). However, we identified a series of diagnostic ions and associated them with specific structural features...
October 26, 2018: Journal of Mass Spectrometry: JMS
Fabio Gomes, Betsegaw Lemma, Dulith Abeykoon, Dapeng Chen, Yan Wang, David Fushman, Catherine Fenselau
A strategy for top-down analysis of branched proteins has been reported earlier, which relies on electron transfer dissociation assisted by collisional activation, and software designed for graphic interpretation of tandem mass spectra and adapted for branched proteins. In the present study the strategy is applied to identify unknown and novel products of reactions in which rationally mutated proteoforms of Rub1 are used to probe the selectivity of E1 and E2 enzymes normally active in ubiquitination. To test and demonstrate this application, components and attachment sites of three branched dimers are deduced and the mutations are confirmed...
October 22, 2018: Journal of Mass Spectrometry: JMS
C B de Lima, C R Ferreira, M P Milazzotto, T J P Sobreira, A A Vireque, R G Cooks
No abstract text is available yet for this article.
October 16, 2018: Journal of Mass Spectrometry: JMS
Nawel Jemil, Noomen Hmidet, Angeles Manresa, Francesc Rabanal, Moncef Nasri
In this work the extraction, structural analysis and identification as well as antimicrobial, anti-adhesive and anti-biofilm activities of lipopeptides produced by Enterobacter cloacae C3 strain were studied. A combination of chromatographic and spectroscopic techniques offers opportunities for a better characterization of the biosurfactant structure. Thin layer chromatography (TLC) and HPLC for amino acid composition determination are used. Efficient spectroscopic techniques have been utilized for investigations on the biochemical structure of biosurfactants, such as Fourier transform infrared (FT-IR) spectroscopy and mass spectrometry analysis...
October 16, 2018: Journal of Mass Spectrometry: JMS
Tobias Binninger, Bernhard Pribyl, Alexandra Pătru, Peter Ruettimann, Saša Bjelić, Thomas J Schmidt
No abstract text is available yet for this article.
October 15, 2018: Journal of Mass Spectrometry: JMS
Ya-Nan Yao, Bin Hu
Conventional electrospray ionization mass spectrometry (ESI-MS) commonly uses capillary tip for sample introduction and ionization. In recent years, ESI-MS using non-capillary substrate tips has attracted growing interest as it allows separation and enrichment of analytes from complex samples due to the analytes-substrate interactions. In this work, model mixtures and functionalized tips were employed to investigate the molecular mechanism of the analyte-substrate interactions. The mixtures were directly loaded on substrate tips, and then temporal responses of analytes were investigated by monitoring selected ion chromatogram (SIC) responses of each analyte...
October 9, 2018: Journal of Mass Spectrometry: JMS
C B Poliseli, M Ribeiro, A P P Tonin, J M Vagula, O O Santos, J V Visentainer, R M Pontes, L A B Moraes, E C Meurer
We report herein a detailed structural study by collision-induced dissociation (CID) of non-glycosylated anthocyanins (anthocyanidines) using electrospray ionization triple quadrupole mass spectrometry (ESI-QqQ) and isotope labeling experiments to understand the fragmentation process often used in mass spectrometry analysis of this class of compounds. Tandem mass spectrometric product ion spectra for three anthocyanidines (cyanidin, delphynidin, and pelargonin) were evaluated to propose fragmentation mechanisms to this natural colorant class of organic compounds...
October 4, 2018: Journal of Mass Spectrometry: JMS
Lisanne J M Kempkes, Jonathan Martens, Giel Berden, Jos Oomens
In mass spectrometry-based peptide sequencing, Electron Transfer Dissociation (ETD) and Electron Capture Dissociation (ECD) have become well established fragmentation methods complementary to collision-induced dissociation (CID). The dominant fragmentation pathways during ETD and ECD primarily involve the formation of c- and z• -type ions by cleavage of the peptide backbone at the N - Cα bond, although neutral losses from amino acid side chains have also been observed. Residue-specific neutral side chain losses provide useful information when conducting database searching and de novo sequencing...
October 3, 2018: Journal of Mass Spectrometry: JMS
Xinyao Jing, Kyle C Edwards, John B Vincent, Carolyn J Cassady
The addition of trivalent chromium, Cr (III), reagents to peptide solutions can increase the intensity of doubly protonated peptides, [M + 2H]2+ , through electrospray ionization (ESI). Three model heptapeptides were studied: neutral (AAAAAAA), acidic (AAEEEAA), and basic (AAAKAAA). The neutral and acidic peptides form almost no 2+ ions in the absence of Cr (III). Twenty Cr (III) complexes were used as potential enhanced protonation reagents, including eleven complexes with non-labile ligands and nine with labile ligands...
October 3, 2018: Journal of Mass Spectrometry: JMS
Lu Wang, Yali Wang, Lushan Yu, Cuirong Sun, Yu Kang, Zeng Su
A mass spectrometric method is introduced for rapid and accurate chiral quantification by examining a trimeric metal complex into which a chiral reference is incorporated with the analyte. Several metal ions (CuII, NiII, MgII, MnII, CoII, ZnII) were selected as the central metal ion, and chiral drugs ezetimibe (EZM) and ambrisentan (AMB) were used as the reference to each other for isomeric differentiation by using electrospray ionization quadrupole time-of-flight mass spectrometry. Doubly charged trimeric cluster ions instead of the singly charged clusters were applied in this study...
October 1, 2018: Journal of Mass Spectrometry: JMS
Bojana Opačić, Adam P Huntley, Brian H Clowers, Peter T A Reilly
Digitally driven mass filter analysis is an advancing field. This work presents a tutorial of digital waveforms, stability diagrams and pseudopotential well plots. Experimental results on digitally-driven mass filter analysis in stability zones A and B are also shown. This work explains duty cycle manipulation of the waveforms to axially trap and eject ions from linear quadrupoles, how to change and distort the stability diagrams to create mass filters and their effects on the pseudopotential well depth. It discusses the sensitivity and resolution that can be obtained and what limits these benchmarks...
September 26, 2018: Journal of Mass Spectrometry: JMS
Hee-Sung Ahn, Seong-Jun Park, Hyun-Gyo Jung, Se Joon Woo, Cheolju Lee
In the hospital, blood samples are collected to monitor patients' health states, and thus various protein-based clinical methods have been developed. However, some proteins are found to change in abundances during the process of blood collection and storage. In order to account such pre-analytical effects, we performed LC-MRM-MS on 15 selected proteins in plasma samples prepared by varying storage time and temperature of whole blood prior to plasma isolation. Two cytosolic proteins, PFN1 and TMSB4X were absolutely quantified using 15 N-labeled recombinant proteins spiked externally...
September 24, 2018: Journal of Mass Spectrometry: JMS
Adam D Kennedy, Bryan M Wittmann, Anne M Evans, Luke A D Miller, Douglas R Toal, Shaun Lonergan, Sarah H Elsea, Kirk L Pappan
Metabolomics is the untargeted measurement of the metabolome, which is comprised of the complement of small molecules detected in a biological sample. As such, metabolomic analysis produces a global biochemical phenotype. It is a technology that has been utilized in the research setting for over a decade. The metabolome is directly linked to and is influenced by genetics, epigenetics, environmental factors and the microbiome - all of which affect health. Metabolomics can be applied to human clinical diagnostics and to other fields such as veterinary medicine, nutrition, exercise, physiology, agriculture/plant biochemistry, and toxicology...
September 22, 2018: Journal of Mass Spectrometry: JMS
Juliette J Commodore, Carolyn J Cassady
The lanthanide ion praseodymium, Pr (III), was employed to study metallated ion formation and electron transfer dissociation (ETD) of twenty-seven biological and model highly acidic phosphopeptides. All phosphopeptides investigated form metallated ions by electrospray ionization (ESI) that can be studied by ETD to yield abundant sequence information. The ions formed are [M + Pr - H]2+ , [M + Pr]3+ , and [M + Pr + H]4+ . All biological phosphopeptide with a chain length of seven or more residues generate [M + Pr]3+ ...
September 17, 2018: Journal of Mass Spectrometry: JMS
Daiki Muko, Takanori Ikenaga, Masanori Kasai, Janice B Rabor, Atsushi Nishitani, Yasuro Niidome
For analysis of low abundance peptides in a tissue section, immunohistochemical staining through antibody-antigen interaction is a usual technique. The antibody is conjugated with a probe moiety that aids in highly sensitive detection. Gold nanoparticles, which show excellent chemical stability and variation of surface modifications, are expected to act as a sensitive mass probe to desorb gold ions (Au+ , Au2 + , Au3 + ) that are distinguishable from fragment ions from organic molecules. Here, green fluorescent proteins (GFP) in a tissue section of a transgenic zebrafish was detected by the gold mass probe conjugated with antibodies...
September 17, 2018: Journal of Mass Spectrometry: JMS
Tahereh Zargar, Mohammad T Jafari, Taghi Khayamian
In this work, a porous graphite sheet is introduced as the substrate in a spray ionization source for ion mobility spectrometry (PGSI-IMS), for the first time. This ionization source has some important advantages in comparison to the hollow needle, which is conventionally used in electrospray ionization. In order to prepare the hydrophilic surface needed to load samples on a graphite substrate, the graphite sheet was treated with hot sulfuric acid solution for 2 h. Some parameters affecting the ionization efficiency were studied and the optimized conditions were found to be 3...
September 17, 2018: Journal of Mass Spectrometry: JMS
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