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Call for 2 Student Assistant (Research Hiwi) Positions:
More infos here:
https://drive.google.com/file/d/1g3kVzfw2tdvuMKpSuAOBhzTxBhvAtyMf/view?usp=sharing
new paper:
Dihydrogen Phosphate anion boosts the detection of sugars in ESI-MS: A combined experimental and computational investigation (9 3 22)
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 be ionized in high abundance for MS detection.
Methods
Hydrogen bond interactions in H2PO4 ̅ - Saccharide anionic systems both experimentally (via Electrospray Fourier transform ion cyclotron resonance mass spectrometry, ESI-FT-ICR-MS) and computationally by several sophisticated density-functional theoretical (DFT and DFT-D3) methods.
Results
H2PO4 ̅ dopant boosts the detection of sugars up to 51-times in 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 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 MS signal intensities of detected [M+H2PO4] ̅ anions of different saccharides and their calculated dissociation enthalpies was revealed. Thus, the variation of MS signal intensities can be very well described to a large extent by variation of calculated saccharides affinities toward H2PO4 ̅ dopant anion, showing that DFT-D3 can very well describe experimental FT-ICR-MS observations.
--> read more about it here:
analyticalsciencejournals.onlinelibrary.wiley.com/doi/abs/10.1002/rcm.9283
job news
I am very excited to start working on a four month's Fellowship at Harvard CfA in the Öberg lab. Let's see how networks of protostars look like ;) (1 3 2022)
Guest Editor for Life special issue "Organic Chemical Evolution regarding the Origin(s) of Life"
Together with Oliver Trapp and Louis D'Hendecourt, I am a Guest Editor for Life special issue "Organic Chemical Evolution regarding the Origin(s) of Life" [mdpi.com/journal/life/special_issues/Origins_of_Life]. By this, we aim to bridge communities from astrochemistry with those from prebiotic chemistry. The detailed contents of the special issue are the following:
A great challenge in Origin(s) of Life research is to identify the transition between inanimate molecules and prebiotic/biotic material. With increasing technology, including space-based telescopes or laboratory instruments, the molecular complexity in space is steadily being unraveled in greater detail. However, a single molecule does not represent life (e.g., no storage of information or emergent functions), but understanding the molecule's evolution through space enables one to probe the emergence of prebiotic chemistry in principle.
This Special Issue is split into two parts:
(i) Astrochemistry --> "Organic Chemical Evolution"
(ii) Prebiotic Chemistry --> "Regarding the Origin(s) of Life"
We will address the evolution of organic molecules along the astronomical timeline, and we will discuss the processes from individual molecules to prebiotic functions. Thus, we have teamed up to combine expertise from Astrochemistry (Louis d'Hendecourt), Prebiotic Chemistry (Oliver Trapp) and respective state-of-the-art (data) analysis (Alexander Ruf).
With respect to Astrochemistry, we will address three topics: (i) Organic Chemistry in Our Galaxy (Molecular Clouds, Protoplanetary Disks); (ii) Organic Chemistry in Our Solar System (Mars, Asteroids/Meteorites, Titan, Comets); (iii) Organic Delivery to Early Earth.
The Prebiotic Chemistry Section will focus on the formation of the first molecules of life. The appearance of complexity and self-organization, the oligomerization of nucleotides, amino acids and sugars leading to functional polymers and building of potential metabolic networks will be addressed. An important aspect here is the fundamental understanding of processes leading to the formation of homochirality.
Chemical (data) analysis has become an increasingly important topic in Origin(s) of Life research, using more powerful instruments and data analytical methods. Here, we will address strategies that target both observational and laboratory data.
I happily invite you to submit a contribution (either as research article or review - we are open to any format). Feel free to share this post, and contact me for any questions (rufalexan@gmail.com).
job news
I am very excited to have won a DAAD Fellowship that enables me to apply network analysis for protostellar data with Karin Öberg at Harvard CfA next year March to June (6 12 2021)
new paper:
Sulfur ion irradiation experiments simulating space weathering of Solar System body surfaces
Organosulfur compound formation (6 12 21)
Context. Sulfur (S) is of prime interest in the context of (astro)chemical evolution and habitability. However, the origin of S-bearing organic compounds in the Solar System is still not well constrained.
Aims. We carried out laboratory experiments to test whether complex organosulfur compounds can be formed when surfaces of icy Solar System bodies are subject to high-energy S ions.
Methods. Non-S-bearing organic residues, formed during the processing of astrophysical H2O:CH3OH:NH3-bearing ice analogs, were irradiated with 105 keV-S7+ ions at 10 K and analyzed by high-resolving FT-ICR-MS. The resulting data were comprehensively analyzed, including network analysis tools.
Results. Out of several thousands of detected compounds, 16% contain at least one sulfur atom (organosulfur (CHNOS) compounds), as verified via isotopic fine structures. These residue-related organosulfur compounds are different from those formed during the S ion irradiation of ices at 10 K. Furthermore, insoluble, apolar material was formed during the sulfur irradiation of residues. Potential organosulfur precursors (CHNO molecules) were identified by means of molecular networks.
Conclusions. This evidence of organosulfur compounds formed by sulfur irradiation of organic residues sheds new light onto the rich and complex scope of pristine organosulfur chemistry in the Solar System, presented in the context of current and future space missions. These results indicate that the space weathering of Solar System bodies may lead to the formation of organosulfur compounds.
--> read more about it here: https://www.aanda.org/.../2021/11/aa41190-21/aa41190-21.html
new paper:
Exploring the link between molecular cloud ices and chondritic organic matter in laboratory (16 6 21)
Carbonaceous meteorites are fragments of asteroids rich in organic material. In the forming solar nebula, parent bodies may have accreted organic materials resulting from the evolution of icy grains observed in dense molecular clouds. The major issues of this scenario are the secondary processes having occurred on asteroids, which may have modified the accreted matter. Here, we explore the evolution of organic analogs of protostellar/protoplanetary disk material once accreted and submitted to aqueous alteration at 150 °C. The evolution of molecular compounds during up to 100 days is monitored by high resolution mass spectrometry. We report significant evolution of the molecular families, with the decreases of H/C and N/C ratios. We find that the post-aqueous products share compositional similarities with the soluble organic matter of the Murchison meteorite. These results give a comprehensive scenario of the possible link between carbonaceous meteorites and ices of dense molecular clouds.
-> read more about it here: https://www.nature.com/articles/s41467-021-23895-2.pdf
new paper:
Unprecedented Molecular Diversity Revealed in Meteoritic Insoluble Organic Matter: The Paris Meteorite’s Case (26 10 20)
The insoluble organic matter (IOM) contained in carbonaceous chondrites has witnessed a diverse suite of processes possibly starting from the evolution of the parent molecular cloud down to the protosolar nebula and finally to asteroidal processes that occurred on the chondrites’ parent bodies. Laser desorption coupled with ultra-high-resolution mass spectrometry reveals that the IOM of the Paris meteorite releases a large diversity of molecules. Various molecular families ranging from hydrogenated amorphous carbon to CHNOS aromatic molecules were detected with heteroatoms (nitrogen, oxygen, and sulfur) mainly incorporated within aromatic structures. Molecules bearing nitrogen atoms present a significant variation in aromaticity. These unprecedented results allow the proposal that small molecules bearing heteroatoms could be trapped in the large macromolecular network of the IOM by hydrophobic interactions. This molecular diversity could originate from different sources, such as the soluble organic matter, the hydrothermal alteration inside the Paris’s parent body, or even generated during the IOM extraction procedure. It has to be noted that some of the molecular diversity may reflect fragmentation and rearrangement of the IOM constituents during the laser desorption ionization, although care was taken to minimize such damage.
-> read more about it here: https://iopscience.iop.org/article/10.3847/PSJ/abb60f/pdf
new paper: A Novel Proteomics-Based Strategy for the Investigation of Peptide Sequences in Extraterrestrial Samples (22 10 20)
new paper about the detection of nucleobases in astrophysical ice analogs - take care with analytics, it's not so trivial. (17 12 19)
The Challenging Detection of Nucleobases from Pre-accretional Astrophysical Ice Analogs
Amino acids, sugars, and nucleobases are considered as the so-called molecular bricks of life, the major subunits of proteins and genetic materials. All three chemical families have been previously detected in meteorites. In dense molecular cloud ice analogs, the formation of a large set of amino acids and sugars (+derivatives) has been observed. In this contribution, we demonstrate that similar ices (H2O:13CH3OH:NH3 ices, 2:1:1) can also lead to the formation of nucleobases. Using combined UPLC-Orbitrap mass spectrometric and UPLC-SRM-triple quadrupole mass spectrometric analyses, we have unambiguously detected cytosine in these primitive, realistic astrophysical ice analogs. Additionally, a huge variety of nucleobase isomers was observed. These results indicate that all central subunits of biochemical materials may have already been present at early stages of chemical evolution of the protosolar nebula, before accretion toward planetesimals. Consequently, the formation of amino acids, sugars, and nucleobases does not necessarily require secondary alteration processes inside meteoritic parent bodies. They might have been supplied from dense molecular cloud ices toward post-accretional objects, such as nonaqueously modified comets, and subsequently delivered onto the early Earth's surface, potentially triggering the emergence of prebiotic chemistry leading to the first living systems.
new paper about high-resolving analysis of organics in ices - NH3 is key. (17 12 19)
Laboratory experiments to unveil the molecular reactivity occurring during the processing of ices in the protosolar nebula
Using laboratory experiments, we investigate the role of photo and thermal degradation in the possible complexification mechanisms of organic matter that may originate from interstellar ices prior to, or during the formation of the Solar System. We perform High Resolution Orbitrap Mass Spectrometry on organic residues formed from the photo- and thermochemical alterations of Interstellar Medium (ISM) dirty ice laboratory analogues. We probe, at the molecular level, the possible effects within the protosolar nebula on the composition and structure of these organic refractory materials obtained from an initial ice composition representative of astrophysical ices. We show that nitrogen incorporation, by competing with the carbon, has a strong influence on the final composition of the residue. NH3 rich ices lead to a group of unsaturated molecules in the final residue, while H2O rich ices lead to saturated ones. Finally, we observe and discuss the strong effect of UV irradiation on the decarboxylation on organic matter and discuss potential implications of this result for the protosolar nebula.
new paper out about sulfur chemistry in astrophysical ices. (11 11 19)
Organosulfur Compounds Formed by Sulfur Ion Bombardment of Astrophysical Ice Analogs: Implications for Moons, Comets, and Kuiper Belt Objects
Carbon, hydrogen, nitrogen, oxygen, and sulfur are the main elements involved in the solid-phase chemistry of various astrophysical environments. Among these elements, sulfur chemistry is probably the least well understood. We investigated whether sulfur ion bombardment within simple astrophysical ice analogs (originating from H2O:CH3OH:NH3, 2:1:1) could trigger the formation of complex organosulfur molecules. Over 1100 organosulfur (CHNOS) molecular formulas (12% of all assigned signals) were detected in resulting refractory residues within a broad mass range (from 100 to 900 amu, atomic mass unit). This finding indicates a diverse, rich and active sulfur chemistry that could be relevant for Kuiper Belt objects (KBO) ices, triggered by high-energy ion implantation. The putative presence of organosulfur compounds within KBO ices or on other icy bodies might influence our view on the search of habitability and biosignatures.
read more about it here:
