Article
Chemistry, Multidisciplinary
Krystyna M. Demkiw, Wouter A. Remmerswaal, Thomas Hansen, Gijsbert A. van der Marel, Jeroen D. C. Codee, K. A. Woerpel
Summary: This study found that acetal substitution reactions of alpha-halogenated five- and six-membered rings can exhibit high stereoselectivity, but this stereoselectivity diminishes as nucleophilicity increases. Computational investigations confirmed that open-form oxocarbenium ions are the reactive intermediates involved, and that hyperconjugative effects and through-space electrostatic interactions contribute to the stabilization of halogen-substituted oxocarbenium ions.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Multidisciplinary
Yuge Chun, Wouter A. Remmerswaal, Jeroen D. C. Codee, K. A. Woerpel
Summary: A single acyloxy group at C-2 can control the outcome of nucleophilic substitution reactions of pyran-derived acetals, but the extent of the neighboring-group participation depends on a number of factors. We show that neighboring-group participation does not necessarily control the stereochemical outcome of acetal substitution reactions with weak nucleophiles. The 1,2-trans selectivity increases with the reactivity of the incoming nucleophile and the decreased electron-donating ability of the neighboring group.
CHEMISTRY-A EUROPEAN JOURNAL
(2023)
Article
Chemistry, Applied
Hylenne Bojorges, Amparo Lopez-Rubio, Maria Jose Fabra, Antonio Martinez-Abad
Summary: This study applied acid methanolysis and separation by anion exchange chromatography to determine the alginate content and M/G ratio. The results showed that methanolysis could be used to estimate the purity and M/G ratio of alginate-rich samples accurately in a single analysis.
CARBOHYDRATE POLYMERS
(2023)
Article
Chemistry, Multidisciplinary
Frank F. J. de Kleijne, Hidde Elferink, Sam J. Moons, Paul B. White, Thomas J. Boltje
Summary: The study characterizes low-populated, rapidly equilibrating mannosyl dioxanium ions using chemical exchange saturation transfer (CEST) NMR spectroscopy, revealing their structure and equilibration kinetics under relevant glycosylation conditions. Highly alpha-selective couplings were observed, suggesting glycosylation takes place via this elusive intermediate.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Multidisciplinary Sciences
Cristina Di Carluccio, Rosa Ester Forgione, Marco Montefiori, Monica Civera, Sara Sattin, Giovanni Smaldone, K. Fukase, Y. Manabe, Paul R. Crocker, Antonio Molinaro, Roberta Marchetti, Alba Silipo
Summary: Siglecs are a group of cell-surface receptors belonging to the I-type lectin family, mostly expressed on innate immune cells, among which CD22 plays a key role in maintaining tolerance and preventing autoimmune responses. This study focused on the interaction of CD22 with sialoglycans, specifically exploring the role of N-glycolyl neuraminic acid (Neu5Gc) in this process. Findings suggested a comparable molecular recognition profile between human and murine forms of CD22, providing insights for innovative diagnostic and therapeutic methodologies in immune response modulation.
Article
Chemistry, Multidisciplinary
Kapil Upadhyaya, Yagya P. Subedi, David Crich
Summary: The study shows that the involvement of distal esters in glycosylation reactions is unfavorable due to the ground state conformation of the ester, which is stereoelectronically impossible. Methylation of the secondary ester to a more labile tertiary ester removes this barrier and makes participation more favorable. However, minor changes in selectivity suggest that distal group participation is not a major stereodirecting factor, even in the tertiary system.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Materials Science, Ceramics
Brian Topper, Elizabeth M. Tsekrekas, Lucas Greiner, Randall E. Youngman, Efstratios Kamitsos, Doris Moncke
Summary: The structures of glasses in the lithium-bismuth orthoborate composition range show deviation from the short-range order structure of crystalline end-members. The increase in bismuth oxide content leads to an increase in the fraction of tetrahedral boron and a continuous rise in glass transition temperature. However, the glass stability reaches a maximum in the multicomponent glass of x = 40.
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
(2022)
Article
Chemistry, Multidisciplinary
Lisanne Sellies, Ruud L. E. G. Aspers, Martin C. Feiters, Floris P. J. T. Rutjes, Marco Tessari
Summary: In recent years, the scope of non-hydrogenative parahydrogen hyperpolarization (nhPHIP) techniques has been expanding, allowing for the detection and quantification of unmodified alpha-amino acids in complex mixtures. This method has shown great potential as demonstrated in human urine samples.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Review
Chemistry, Physical
Francisco Zaera
Summary: Catalysis in industrial chemical processes has long been studied through various spectroscopic techniques like vibrational and X-ray spectroscopies, allowing for a molecular-level understanding of catalytic mechanisms. These techniques help researchers explore the intricate details of catalytic processes and advancements in the field.
JOURNAL OF CATALYSIS
(2021)
Article
Materials Science, Multidisciplinary
Heng Li, Jianmin Jiao, Wang Xie, Yue Zhao, Chen Lin, Juli Jiang, Leyong Wang
Summary: Single crystal X-ray diffraction is a reliable method for determining molecular structures, but it has limitations with oily organic molecules. A new crystallization chaperone called TMAPA was developed to overcome this limitation and successfully determined the structures of 51 organic guest molecules. The introduction of anthracene moieties in TMAPA allowed for efficient capture of guest molecules. This work opens up new possibilities for identifying and determining the conformation of unknown oily organic molecules.
ACS MATERIALS LETTERS
(2023)
Article
Chemistry, Physical
Oskar Asvany, Sven Thorwirth, Philipp C. C. Schmid, Thomas Salomon, Stephan Schlemmer
Summary: The ro-vibrational and pure rotational spectra of the linear ion HC3O+ were studied using a novel action spectroscopic technique named leak-out spectroscopy (LOS). A total of 45 ro-vibrational transitions within the fundamental band of the ν(1) C-H stretching mode were measured. Surprisingly, two hot bands were detected despite the cryogenic operation temperature. A new double-resonance rotational measurement scheme was established based on the LOS method. In addition, a pulsed laser system was employed to record a low resolution vibrational spectrum.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2023)
Article
Chemistry, Multidisciplinary
Matthew Kollman, Xiao Jiang, Samuel J. Thompson, Ofei Mante, David C. Dayton, Hou-min Chang, Hasan Jameel
Summary: The amino alkylation of kraft lignins using the Mannich reaction is a versatile technique that can be used for analytical derivatization, improving hydrophilicity, or enhancing metal ion adsorptive capacity. This study utilized a quantitative technique combining 2D HSQC NMR and C-13 NMR spectroscopy to directly examine the structure of aminated lignins. The results indicated that low molecular weight lignins had a higher degree of amine substitution compared to high molecular weight fractions, with no significant impact observed from pH levels or different amine species.
Article
Chemistry, Multidisciplinary
Pengbo Ye, Xuan Liu, Gang Wang, Lei Liu
Summary: An asymmetric alkylation method catalyzed by nickel(II) has been developed for preparing beta-alkoxyl carbonyl moieties with diverse alpha-substituents from acyclic oxocarbenium ions generated in situ from corresponding acetals with carboxylic acid derivatives. The method exhibits broad scope of acetals and carboxylic acid derivatives with excellent enantioselectivity and good functional group compatibility, and can be conducted in a gram-scale without obvious loss of efficiency.
CHINESE CHEMICAL LETTERS
(2021)
Article
Chemistry, Multidisciplinary
Despoina Andriotou, Sylvain Duval, Christophe Volkringer, Xavier Trivelli, William E. Shepard, Thierry Loiseau
Summary: The reactivity of aryl monocarboxylic acids as complexing agents for the ethoxide niobium(V) precursor has been investigated and eight coordination complexes were isolated. The formation of the niobium oxo clusters was characterized by infrared and liquid H-1 NMR spectroscopy.
CHEMISTRY-A EUROPEAN JOURNAL
(2022)
Article
Chemistry, Multidisciplinary
Andres G. Santana, Laura Montalvillo-Jimenez, Laura Diaz-Casado, Enrique Mann, Jesus Jimenez-Barbero, Ana M. Gomez, Juan Luis Asensio
Summary: Glycosyl sulfoxides are important in the synthesis of complex oligosaccharides and have been used as model substrates. A systematic NMR study showed that glycosyl triflates play a crucial role in these glycosylations, despite the presence of the acceptor alcohol, and identified the formation of covalent donor/acceptor sulfonium adducts as the main competing reaction. This non-productive consumption of the acceptor could limit the reaction yield.
CHEMISTRY-A EUROPEAN JOURNAL
(2021)
Article
Chemistry, Analytical
Jonathan Martens, Rianne E. van Outersterp, Jitse Oosterhout, Christoph R. Gebhardt, Giel Berden, Udo F. H. Engelke, Ron A. Wevers, Filip Cuyckens, Jos Oomens
Summary: Infrared ion spectroscopy (IRIS) is a useful tool for identifying molecular structures detected in mass spectrometry (MS) experiments. However, coupling LC and IRIS is challenging due to the different timescales. To address this, we propose a heartcutting LC-IRIS approach using two switching valves and two sample loops as an alternative to direct coupling.
ANALYTICAL CHEMISTRY
(2023)
Article
Chemistry, Multidisciplinary
Tobias Preitschopf, Floriane Sturm, Iuliia Stroganova, Alexander K. Lemmens, Anouk M. Rijs, Ingo Fischer
Summary: Isolated 2-phenylallyl radicals (2-PA) generated from a nitrite precursor were studied using IR/UV ion dip spectroscopy with free electron laser radiation. 2-PA is a resonance-stabilized radical involved in the formation of polycyclic aromatic hydrocarbons (PAH) in combustion and interstellar space. Gas-phase IR spectrum was used to identify the radical, and several bimolecular reaction products were identified, indicating efficient formation of PAH through self-reaction and reactions with decomposition products of 2-PA. Possible mechanisms were discussed and the chemistry of 2-PA was compared with related radicals.
CHEMISTRY-A EUROPEAN JOURNAL
(2023)
Article
Chemistry, Physical
Alexander K. Lemmens, Cameron J. Mackie, Alessandra Candian, Timothy M. J. Lee, Alexander G. G. M. Tielens, Anouk M. Rijs, Wybren Jan Buma
Summary: This study validates the reliability of polycyclic aromatic hydrocarbons (PAHs) size distribution in the interstellar medium (ISM) using the calculated intrinsic infrared (IR) spectra. By comparing calculations from the NASA Ames PAH IR spectroscopic database to gas-phase experimental absorption IR spectra, it was found that the 11.2/3.3 mu m intensity ratio is consistently underestimated by 34%. However, higher level anharmonic calculations show good agreement with the experiments. Based on these findings, the intrinsic ratio of these modes was adjusted and incorporated into an interstellar PAH emission model, suggesting that typical PAH sizes in reflection nebulae are actually in the range of 40 to 55 carbon atoms.
FARADAY DISCUSSIONS
(2023)
Article
Chemistry, Inorganic & Nuclear
Marco Giampa, Davide Corinti, Alessandro Maccelli, Simonetta Fornarini, Giel Berden, Jos Oomens, Sabrina Schwarzbich, Thorsten Glaser, Maria Elisa Crestoni
Summary: This study investigates the binding ability of a dinuclear copper complex with phosphate diester ligands, revealing its interaction modes with phosphate groups and mononucleotides. The results suggest that this interaction contributes to the observed anticancer activity.
INORGANIC CHEMISTRY
(2023)
Article
Chemistry, Physical
Ake Andersson, Vasyl Yatsyna, Mathieu Linares, Anouk Rijs, Vitali Zhaunerchyk
Summary: We investigate the gas-phase structure of the neutral pentaalanine peptide using supersonic jet cooling, infrared multiphoton dissociation, and vacuum-ultraviolet action spectroscopy. The molecule assumes multiple stable conformations, mainly of two structure types, with the most stable conformation featuring a C5 ring at the N-terminus and a 310-helix backbone with two beta-turns. The conformational preferences of pentaalanine are also evaluated using Born-Oppenheimer molecular dynamics, revealing a systematic frequency shift caused by a nonzero simulation time step.
JOURNAL OF PHYSICAL CHEMISTRY A
(2023)
Article
Chemistry, Physical
Bruno Martinez-Haya, Juan Ramon Aviles-Moreno, Francisco Gamez, Jonathan Martens, Jos Oomens, Giel Berden
Summary: The interaction between organic molecules and oxonium cations in their solvation shell can lead to the formation of dynamic supramolecular structures that undergo recurrent changes in their host-guest chemical identity. This phenomenon is illustrated in proton-bonded complexes of water with polyether macrocycles. Despite water's lower proton affinity compared to the ether group, water actually retains the proton as H3O+ with increased stability as the coordination number increases. Hindrance in many-fold coordination induces dynamic reversible interconversion between (ether)·H3O+ (etherH+)·H2O. Infrared action ion spectroscopy reveals the vibrational signatures of loose proton bonding in these systems, which cannot be described by static equilibrium structures but can be accurately modeled using ab initio molecular dynamics.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2023)
Article
Biochemical Research Methods
Anouk M. Rijs, Agathe Depraz Depland, Iuliia Stroganova, Christopher A. Wootton
Summary: Ion mobility mass spectrometry (IM-MS) is an excellent method to study the structure of amyloidogenic protein and peptide aggregates. However, it is challenging to obtain detailed structural information on the early-stage intermediates due to their complex environment. Trapped ion mobility spectrometry (TIMS) is a high-resolution technique that can be used to analyze protein conformations. By optimizing the instrumental parameters of TIMS-qToF-MS, researchers can investigate the aggregation process of peptide aggregates.
JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY
(2023)
Article
Physics, Atomic, Molecular & Chemical
Yining Jiang, Jean-Xavier Bardaud, Nouha Ayadi, Marc Lecouvey, Chantal Houee-Levin, Giel Berden, Jos Oomens, Debora Scuderi
Summary: The oxidation of single amino acids proline and glutamic acid, as well as Met-containing model peptides, by OH radicals produced by g-radiolysis was studied using tandem mass spectrometry and infrared multiple-photon dissociation spectroscopy. The thioether group of methionine was identified as a common target of OH free radicals, leading to the formation of a S+ radical cation. The final fate of these radicals is still unknown, but the final stable products of oxidation were identified as mostly methionine sulfoxide.
INTERNATIONAL JOURNAL OF MASS SPECTROMETRY
(2023)
Article
Agriculture, Multidisciplinary
Davide Corinti, Lucretia Rotari, Maria Elisa Crestoni, Simonetta Fornarini, Jos Oomens, Giel Berden, Aura Tintaru, Barbara Chiavarino
Summary: In this study, mass spectrometry and spectroscopic techniques were used to analyze naringenin (Nar) and its structural isomer, naringenin chalcone (ChNar). It was found that they have slight structural differences and can be distinguished by specific vibrational features in the infrared spectra.
JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY
(2023)
Article
Chemistry, Physical
Brandon C. Stevenson, Giel Berden, Jonathan Martens, Jos Oomens, P. B. Armentrout
Summary: Infrared multiple photon dissociation (IRMPD) action spectroscopy was used to evaluate the complexes formed between the aromatic amino acids phenylalanine (Phe), tyrosine (Tyr), and tryptophan (Trp) and cationized ZnCl+ and CdCl+. The results showed that the dominant binding motif for MCl+(Phe) and MCl+(Tyr) is a tridentate structure, where the metal atom coordinates with the backbone amino nitrogen and carbonyl oxygen, as well as the aryl ring. For the ZnCl+(Trp) system, the experimental spectrum indicated a similar binding motif with the zinc atom coordinating with the backbone nitrogen and carbonyl oxygen and either the pyrrole ring or the benzene ring of the indole side chain.
JOURNAL OF PHYSICAL CHEMISTRY A
(2023)
Article
Chemistry, Multidisciplinary
Mathias Paul, Thomas Thomulka, Wacharee Harnying, Joerg-Martin Neudoerfl, Charlie R. Adams, Jonathan Martens, Giel Berden, Jos Oomens, Anthony J. H. M. Meijer, Albrecht Berkessel, Mathias Schaefer
Summary: Hydroxycarbenes can be generated and analyzed in the gas phase through collision-induced decarboxylation of alpha-ketocarboxylic acids. In this study, it was found that the flexible 3-(trimethylammonio)-propylhydroxycarbene exhibited stability and did not undergo H-shift to aldehyde or enol. This novel inhibition of quantum-mechanical hydrogen tunneling is attributed to intramolecular H-bonding between the mildly acidic alpha-ammonio C-H bonds and the hydroxyl carbene's C-atom.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Chemistry, Physical
Laura Finazzi, Jonathan Martens, Giel Berden, Jos Oomens
Summary: Intramolecular radical and proton migration play important roles in dissociation reactions in gas phase tandem mass spectrometry processes. Understanding the mechanism of these processes requires experiments and calculations on ion structures. The combination of ion trap mass spectrometry with IR laser spectroscopy provides an effective method to explore the details of ion structures. In this study, IRMPD spectroscopy and DFT calculations are used to investigate the reactant and product ion structures of a homolytic bond cleavage reaction.
Article
Chemistry, Analytical
Ruben F. Kranenburg, Henk-Jan Ramaker, Yannick Weesepoel, Peter W. F. Arisz, Peter H. J. Keizers, Annette van Esch, Cathelijne Zieltjens-van Uxem, Jorrit D. J. van den Berg, Janneke W. Hulshof, Sjors Bakels, Anouk M. Rijs, Arian C. van Asten
Summary: The need for on-site testing of MDMA formulations encountered by law enforcement and border security has led to the exploration of near-infrared spectroscopy. This technique shows promise in terms of rapid analysis, non-invasive detection, and suitability for portable operation. The NIR spectrum of MDMA, specifically a peak at around 2000 nm, is attributed to water molecules of crystallization in the MDMA lattice. Understanding the different forms of MDMA and their detection challenges will enhance the effectiveness of on-site NIR-based drug detection.
FORENSIC CHEMISTRY
(2023)
Article
Chemistry, Physical
Musleh Uddin Munshi, Giel Berden, Jos Oomens
Summary: In this study, we utilized fingerprint infrared multiple-photon dissociation spectra to investigate the monohydrated coordination complex of cobalt(II) and the macrocycle 1,4,7,10,13-pentaoxacyclopentadecane (or 15-crown-5). The metal-ligand complexes were generated through electrospray ionization and their IR action spectra were recorded using a quadrupole ion trap mass spectrometer with the free-electron laser FELIX. By comparing the obtained spectral data with computed vibrational spectra, we determined the electronic structure and chelation motif. We found that the gas-phase complex adopts a quartet spin state and the chelation geometry is pseudo-octahedral.
JOURNAL OF PHYSICAL CHEMISTRY A
(2023)
Article
Chemistry, Multidisciplinary
Rianne E. E. van Outersterp, Jonathan Martens, Giel Berden, Arnaud Lubin, Filip Cuyckens, Jos Oomens
Summary: The identification of biotransformation products of drug compounds is crucial for drug development. Liquid chromatography-mass spectrometry (LC-MS) has become the preferred method for metabolite profiling due to its high sensitivity and selectivity. However, determining the full molecular structure of the detected metabolites, including the exact biotransformation site, remains challenging using MS alone.
