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  • 1
    Language: English
    In: Proceedings of the National Academy of Sciences of the United States of America, 16 February 2010, Vol.107(7), pp.2763-8
    Description: Numerous descriptions of organic molecules present in the Murchison meteorite have improved our understanding of the early interstellar chemistry that operated at or just before the birth of our solar system. However, all molecular analyses were so far targeted toward selected classes of compounds with a particular emphasis on biologically active components in the context of prebiotic chemistry. Here we demonstrate that a nontargeted ultrahigh-resolution molecular analysis of the solvent-accessible organic fraction of Murchison extracted under mild conditions allows one to extend its indigenous chemical diversity to tens of thousands of different molecular compositions and likely millions of diverse structures. This molecular complexity, which provides hints on heteroatoms chronological assembly, suggests that the extraterrestrial chemodiversity is high compared to terrestrial relevant biological- and biogeochemical-driven chemical space.
    Keywords: Meteoroids ; Extraterrestrial Environment -- Chemistry ; Organic Chemicals -- Analysis
    ISSN: 00278424
    E-ISSN: 1091-6490
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  • 2
    Language: English
    In: Analytical Chemistry, August 7, 2012, Vol.84(15), p.6586(9)
    Description: A novel approach using a combination of capillary electrophoresis/mass spectrometry (CE/MS) and off-line Fourier transform ion cyclotron resonance mass spectrometry (FTICR-MS) revealed the structural details of acidic constituents of atmospheric organic aerosol. Both techniques utilized electrospray ionization (ESI), a soft ionization method, to facilitate the analysis of complex mixtures of organic compounds. CE/ESI-MS using an UltraTrol LN-precoated capillary and acidic background electrolytes at different pH values (2.5 and 4.7) was used to differentiate between weak (carboxylic) and strong (sulfonic) organic acids. On the basis of the electrophoretic mobility, m/z constraints from CE/ESI(-)-MS, and elemental composition information retrieved from off-line FTICR-MS, a variety of aliphatic and aromatic carboxylic acids (CHO-bearing molecules), nitrogen-containing carboxylic acids (CHON-bearing molecules), organosulfates (CHOS-bearing molecules), and (nitrooxy)organosulfates (CHONS-bearing molecules) were tentatively identified in the Oasis-HLB-extracted urban PM2.5 (particulate matter with an aerodynamic diameter of 〈2.5 [mu]m). The chemical known/unknown structures of detected compounds were confirmed by the semiempirical Offord model (effective mobility linearly correlated to Z/[M.sup.2/3]). The majorities of the identified compounds are products of atmospheric reactions and are known contributors to secondary organic aerosols.
    Keywords: Ionization -- Analysis ; Aerosols -- Chemical Properties ; Aerosols -- Thermal Properties ; Electrophoresis -- Analysis ; Fourier Transform Infrared Spectroscopy -- Usage
    ISSN: 0003-2700
    Source: Cengage Learning, Inc.
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  • 3
    Language: English
    In: Science, Oct 28, 2016, Vol.354(6311), p.456(4)
    Description: Although sulfur is an essential element for marine primary production and critical for climate processes, little is known about the oceanic pool of nonvolatile dissolved organic sulfur (DOS). We present a basin-scale distribution of solid-phase extractable DOS in the East Atlantic Ocean and the Atlantic sector of the Southern Ocean. Although molar DOS versus dissolved organic nitrogen (DON) ratios of 0.11 [+ or -] 0.024 in Atlantic surface water resembled phytoplankton stoichiometry (sulfur/nitrogen ~ 0.08), increasing dissolved organic carbon (DOC) versus DOS ratios and decreasing methionine-S yield demonstrated selective DOS removal and active involvement in marine biogeochemical cycles. Based on stoichiometric estimates, the minimum global inventory of marine DOS is 6.7 petagrams of sulfur, exceeding all other marine organic sulfur reservoirs by an order of magnitude. 10.1126/science.aaf7796
    Keywords: Chemical Oceanography – Research ; Sulfur – Chemical Properties ; Sulfur – Environmental Aspects
    ISSN: 0036-8075
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  • 4
    Language: English
    In: Science (New York, N.Y.), 26 May 2017, Vol.356(6340), pp.813
    Description: Dittmar proposed that mixing alone can explain our observed decrease in marine dissolved organic sulfur with age. However, their simple model lacks an explanation for the origin of sulfur-depleted organic matter in the deep ocean and cannot adequately reproduce our observed stoichiometric changes. Using radiocarbon age also implicitly models the preferential cycling of sulfur that they are disputing.
    Keywords: Sulfur
    ISSN: 00368075
    E-ISSN: 1095-9203
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  • 5
    In: Plant Journal, January 2014, Vol.77(1), pp.31-45
    Description: Sulfur plays a crucial role in protein structure and function, redox status and plant biotic stress responses. However, our understanding of sulfur metabolism is limited to identified pathways. In this study, we used a high‐resolution ourier transform mass spectrometric approach in combination with stable isotope labeling to describe the sulfur metabolome of . Databases contain roughly 300 sulfur compounds assigned to rabidopsis. In comparative analyses, we showed that the overlap of the expected sulfur metabolome and the mass spectrometric data was surprisingly low, and we were able to assign only 37 of the 300 predicted compounds. By contrast, we identified approximately 140 sulfur metabolites that have not been assigned to the databases to date. We used our method to characterize the γ‐glutamyl transferase mutant , which is involved in the vacuolar breakdown of glutathione conjugates in detoxification reactions. Although xenobiotic substrates are well known, only a few endogenous substrates have been described. Among the specifically altered sulfur‐containing masses in the mutant, we characterized one endogenous glutathione conjugate and a number of further candidates for endogenous substrates. The small percentage of predicted compounds and the high proportion of unassigned sulfur compounds identified in this study emphasize the need to re‐evaluate our understanding of the sulfur metabolome.
    Keywords: 4 ; Γ‐Glutamyl Transferase ; Glutathione Conjugates ; Isotope Labeling ; ‐ ; Metabolomics ; Arabidopsis Thaliana
    ISSN: 0960-7412
    E-ISSN: 1365-313X
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  • 6
    Language: English
    In: Journal of Chromatography A, May 31, 2013, Vol.1292, p.51(15)
    Description: To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.chroma.2013.04.017 Byline: Sara Forcisi, Franco Moritz, Basem Kanawati, Dimitrios Tziotis, Rainer Lehmann, Philippe Schmitt-Kopplin Abstract: acents A review of advanced instrumental techniques for non-targeted metabolomics is presented. acents Instrumental differences between various mass analyzers are considered. acents Coupling of modern mass analyzers to HPLC and UHPLC are treated. acents A real case application showing the importance of mass difference networking is presented. Author Affiliation: (a) Research Unit Analytical BioGeoChemistry, Helmholtz Zentrum Munchen, German Research Center for Environment Health, D-85764 Neuherberg, Germany (b) Chair of Analytical Food Chemistry, Technische Universitat Munchen, D-85354 Freising-Weihenstephan, Germany (c) Division of Clinical Chemistry and Pathobiochemistry (Central Laboratory), University Hospital Tubingen, D-72076 Tubingen, Germany (d) Paul-Langherans-Institute Tuebingen, Member of German Centre for Diabetes Research (DZD), University of Tubingen, D-72076 Tubingen, Germany (e) German Center for Diabetes Research (DZD), Germany
    Keywords: Mass Spectrometry ; Liquid Chromatography ; Biogeochemistry
    ISSN: 0021-9673
    Source: Cengage Learning, Inc.
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  • 7
    Language: English
    In: PLoS ONE, 2012, Vol.7(7), p.e39860
    Description: Systems Biology is a field in biological science that focuses on the combination of several or all “omics”-approaches in order to find out how genes, transcripts, proteins and metabolites act together in the network of life. Metabolomics as analog to genomics, transcriptomics and proteomics is more and more integrated into biological studies and often transcriptomic and metabolomic experiments are combined in one setup. At a first glance both data types seem to be completely different, but both produce information on biological entities, either transcripts or metabolites. Both types can be overlaid on metabolic pathways to obtain biological information on the studied system. For the joint analysis of both data types the MassTRIX webserver was updated. MassTRIX is freely available at www.masstrix.org .
    Keywords: Research Article ; Biology ; Chemistry ; Computer Science ; Chemistry ; Computational Biology ; Computer Science ; Biochemistry
    E-ISSN: 1932-6203
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  • 8
    Language: English
    In: Geochimica et Cosmochimica Acta, Feb 1, 2014, Vol.126, p.321(17)
    Description: To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.gca.2013.11.009 Byline: Oliver J. Lechtenfeld, Gerhard Kattner, Ruth Flerus, S. Leigh McCallister, Philippe Schmitt-Kopplin, Boris P. Koch Abstract: More than 90% of the global ocean dissolved organic carbon (DOC) is refractory, has an average age of 4000-6000years and a lifespan from months to millennia. The fraction of dissolved organic matter (DOM) that is resistant to degradation is a long-term buffer in the global carbon cycle but its chemical composition, structure, and biochemical formation and degradation mechanisms are still unresolved. We have compiled the most comprehensive molecular dataset of 197 Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) analyses from solid-phase extracted marine DOM covering two major oceans, the Atlantic sector of the Southern Ocean and the East Atlantic Ocean (ranging from 50[degrees]N to 70[degrees]S). Molecular trends and radiocarbon dating of 34 DOM samples (comprising [DELTA].sup.14C values from -229a[degrees] to -495a[degrees]) were combined to model an integrated degradation rate for bulk DOC resulting in a predicted age of 〉24ka for the most persistent DOM fraction. First order kinetic degradation rates for 1557 mass peaks indicate that numerous DOM molecules cycle on timescales much longer than the turnover of the bulk DOC pool (estimated residence times of up to ~100ka) and the range of validity of radiocarbon dating. Changes in elemental composition were determined by assigning molecular formulae to the detected mass peaks. The combination of residence times with molecular information enabled modelling of the average elemental composition of the slowest degrading fraction of the DOM pool. In our dataset, a group of 361 molecular formulae represented the most stable composition in the oceanic environment ("island of stability"). These most persistent compounds encompass only a narrow range of the molecular elemental ratios H/C (average of 1.17[+ or -]0.13), and O/C (average of 0.52[+ or -]0.10) and molecular masses (360[+ or -]28 and 497[+ or -]51Da). In the Weddell Sea DOC concentrations in the surface waters were low (46.3[+ or -]3.3[mu]M) while the organic radiocarbon was significantly more depleted than that of the East Atlantic, representing average surface water DOM ages of 4920[+ or -]180a. These results are in accordance with a highly degraded DOM in the Weddell Sea surface water as also shown by the molecular degradation index I.sub.DEG obtained from FT-ICR MS data. Further, we identified 339 molecular formulae which probably contribute to an increased DOC concentration in the Southern Ocean and potentially reflect an accumulation or enhanced sequestration of refractory DOC in the Weddell Sea. These results will contribute to a better understanding of the persistent nature of marine DOM and its role as an oceanic carbon buffer in a changing climate. Article History: Received 6 May 2013; Accepted 7 November 2013 Article Note: (miscellaneous) Associate editor: Elizabeth Ann Canuel
    Keywords: Radiocarbon Dating -- Analysis ; Archaeological Dating -- Analysis ; Water Resources -- Analysis ; Carbon Cycle -- Analysis
    ISSN: 0016-7037
    Source: Cengage Learning, Inc.
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  • 9
    Language: English
    In: Journal of Chromatography A, Sept 12, 2014, Vol.1359, p.91(9)
    Description: To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.chroma.2014.07.021 Byline: Michael Witting, Tanja Verena Maier, Steve Garvis, Philippe Schmitt-Kopplin Abstract: acents Sub-2-[mu]m core-shell column for lipid separation. acents Enhanced separation of isomeric species. acents Higher coverage of the Caenorhabditis elegans lipidome. Author Affiliation: (a) Research Unit Analytical BioGeoChemistry, Helmholtz Zentrum Munchen, German Research Center for Environmental Health, Ingolstaedter Landstrasse 1, 85764 Neuherberg, Germany (b) Laboratoire de Biologie Moleculaire de la Cellule, UMR5239 CNRS/ENS Lyon/UCBL/HCL, Ecole normale superieure de Lyon 46, allee d'Italie, 69364 Lyon cedex 07, France (c) Chair of Analytical Food Chemistry, Technische Universitat Munchen, Alte Akademie 10, D-85354 Freising-Weihenstephan, Germany Article History: Received 9 May 2014; Revised 7 July 2014; Accepted 8 July 2014
    Keywords: Mass Spectrometry ; Caenorhabditis Elegans ; Liquid Chromatography ; Biogeochemistry
    ISSN: 0021-9673
    Source: Cengage Learning, Inc.
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  • 10
    Language: English
    In: Journal of Chromatography A, 12 September 2014, Vol.1359, pp.91-99
    Description: Lipid profiling or lipidomics is currently applied in many different research fields. It refers to the global analysis of a samples lipid content using different analytical chemistry methods, with mass spectrometry as the mostly employed technology. We developed a comprehensive in-depth analysis method for the lipidome of the soil-dwelling nematode , a widely used model organism. Four different columns were compared with a generic gradient and a novel sub-2-μm core–shell column, Waters Cortecs C18, showed superior performance in case of chromatographic peak characteristics, e.g. plate numbers and number of detected lipid features. Retention time deviation was generally less than 1% within one column and below 5% for columns from different batches. Intensity variation was lower than 30% for most detected features. Improved chromatographic separation showed enhanced resolution for isomeric lipids and allowed collection of highly detailed MS/MS spectra for lipid identification. In total 1304 lipid features were detected in positive ionization mode and 265 in negative mode. Lipids from different classes were annotated and MS/MS spectra obtained by data dependent fragmentation were used for identification purposes.
    Keywords: Lipidomics ; Method Development ; Caenorhabditis Elegans ; Mass Spectrometry ; Sub-2-Μm Core–Shell Column ; Chemistry
    ISSN: 0021-9673
    E-ISSN: 18733778
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