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The rich diversity and complexity of organic matter found in meteorites is rapidly expanding our knowledge and understanding of extreme environments from which the early solar system emerged and evolved. Here, we report the discovery of a hitherto unknown chemical class, dihydroxymagnesium carboxylates [(OH)2MgO2CR]-, in meteoritic soluble organic matter. High collision energies, which are required for fragmentation, suggest substantial thermal stability of these Mg-metalorganics (CHOMg compounds). This was corroborated by their higher abundance in thermally processed meteorites. CHOMg compounds were found to be present in a set of 61 meteorites of diverse petrological classes. The appearance of this CHOMg chemical class extends the previously investigated, diverse set of CHNOS molecules. A connection between the evolution of organic compounds and minerals is made, as Mg released from minerals gets trapped into organic compounds. These CHOMg metalorganic compounds and their relation to thermal processing in meteorites might shed new light on our understanding of carbon speciation at a molecular level in meteorite parent bodies.

Infection of Arabidopsis with avirulent Pseudomonas syringae and exposure to nitrogen dioxide (NO2) both trigger hypersensitive cell death (HCD) that is characterized by the emission of bright blue‐green (BG) autofluorescence under UV illumination. The aim of our current work was to identify the BG fluorescent molecules and scrutinize their biosynthesis, localization, and functions during the HCD. Compared with wild‐type (WT) plants, the phenylpropanoid‐deficient mutant fah1 developed normal HCD except for the absence of BG fluorescence. Ultrahigh resolution metabolomics combined with mass difference network analysis revealed that WT but not fah1 plants rapidly accumulate dehydrodimers of sinapic acid, sinapoylmalate, 5‐hydroxyferulic acid, and 5‐hydroxyferuloylmalate during the HCD. FAH1‐dependent BG fluorescence appeared exclusively within dying cells of the upper epidermis as detected by microscopy. Saponification released dehydrodimers from cell wall polymers of WT but not fah1 plants. Collectively, our data suggest that HCD induction leads to the formation of free BG fluorescent dehydrodimers from monomeric sinapates and 5‐hydroxyferulates. The formed dehydrodimers move from upper epidermis cells into the apoplast where they esterify cell wall polymers. Possible functions of phenylpropanoid dehydrodimers are discussed. [ABSTRACT FROM AUTHOR]

Rationale: Sugars are key molecules of life but challenging to detect via electrospray ionization mass spectrometry (ESI‐MS). Unfortunately, sugars are challenging analytes for mass spectrometric methods due to their high gas‐phase deprotonation energies and low gas‐phase proton affinities which make them difficult to ionize in high abundance for MS detection. Methods: Hydrogen‐bond interactions in H2PO4−–saccharide anionic systems were studied both experimentally (via electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry, ESI‐FT‐ICR‐MS) and computationally by several sophisticated density‐functional theoretical methods (DFT and DFT‐D3). Results: The H2PO4− dopant boosts the detection of sugars up to 51‐times in the case of sucrose and up to 263‐times for glucose (at 0.1 ppm concentration level). H2PO4− binds toward sugar molecules with noticeably more hydrogen bonds than the established dopant chloride Cl− does, with increasing binding energies in the order: Monosaccharides < Trisaccharides < Disaccharides. Analysis of a complex oak plant sample revealed that NH4H2PO4 specifically labeled a diverse set of sugar‐type plant metabolites in the form of [M + H2PO4]− complexes. Conclusions: We reveal the mechanism of interaction of H2PO4− with different sugars and glycosylated organic compounds, which significantly enhances their ionization in mass spectrometry. A computational and experimental investigation is presented. A strong correlation between the MS signal intensities of detected [M + H2PO4]− anions of different saccharides and their calculated dissociation enthalpies was revealed. Thus, the variation in MS signal intensities can be very well described to a large extent by the variation in calculated saccharide affinities toward the H2PO4− dopant anion, showing that DFT‐D3 can very well describe experimental FT‐ICR‐MS observations. [ABSTRACT FROM AUTHOR]

The world of Fourier‐transform ion cyclotron resonance (FT‐ICR) mass spectrometry has witnessed, especially in the last 30 years significant advances in many fields of science, such as electronics, magnets, new ICR cell designs, developed ICR event sequences, modern external ionization sources, and linear ion beam guides, as well as modern vacuum technology. In this review, a brief account is given focusing especially on the studies performed in Wanczek's group and ICR research laboratory at the University of Bremen. An FT‐ICR mass spectrometer has been developed with a high magnetic field superconducting magnet, operating at 4.7 T. At this magnetic field, a trapping time of 13.5 h was obtained with 30% efficiency. For the tetrachloromethane molecular ion, m/z 166, a mass‐resolving power m/Δm = 1.5 × 106 was measured at a pressure of 2 × 10−8 Torr. The transition from magnet sweep to frequency sweep and the application of Fourier‐transform has greatly enhanced the ICR technology. External ion sources were invented and differential pumping schemes were developed for enabling ultrahigh vacuum condition for ICR detection, while guiding ions at relatively higher pressures, during their flight to the ICR cell. With the external ion source, a time‐of‐flight ICR tandem instrument is built. A method to measure the ion flight time and to trap the ions in the ICR cell is described. Many ICR cell characteristics such as z‐axis ion ejection and coupling of radial and axial ion motions in a superposed homogeneous magnetic and inhomogeneous trapping electric field were extensively studied. Gas‐phase ion–molecule reactions of several reactive inorganic compounds with a focus on phosphorous and sulfur as well as silicon chemistry were also studied in great detail. The gas‐phase ion chemistry of several trifluoromethyl‐reagents such as trifluoromethyltrimethylsilane and tris(trifluoromethyl)phosphine were also investigated in ICR. Dual polarities multisegmented ICR cells were invented and deeply characterized. Sophisticated ICR pulse event programs were developed to enable long‐range ion–ion interactions between simultaneously trapped positive and negative ions. [ABSTRACT FROM AUTHOR]