Article
Biochemical Research Methods
Roy E. Hoffman
Summary: Thallium chemical shifts are highly sensitive to chemical and physical conditions, making accurate referencing a challenge. Past studies often reference to TlNO3 solution in water at infinite dilution, with measured shifts of -22.16 and 0.75 ppm for Tl-203 and Tl-205. Furthermore, the behavior of thallium chemical shifts with concentration and temperature are discussed in relation to ionic association.
JOURNAL OF MAGNETIC RESONANCE
(2021)
Article
Biochemical Research Methods
Roy Hoffman
Summary: The C-13 signals of adamantane serve as a chemical shift standard in solid-state NMR. The chemical shifts are measured with higher accuracy than previous reports and across a temperature range from -2 to 70 degrees C. By combining the chemical shifts of adamantane's NMR signals, an accurate chemical shift can be obtained without directly measuring the temperature.
JOURNAL OF MAGNETIC RESONANCE
(2022)
Article
Chemistry, Multidisciplinary
Subhrakant Jena, Chinmay Routray, Juhi Dutta, Himansu S. Biswal
Summary: The deshielding or downfield C-13 NMR chemical shift of amide carbonyl carbon upon H-bonding is commonly observed, while the very first observation of an upfield C-13 NMR of thiocarbonyl carbon in thioamides upon H-bonding led to the exploration of the physical origin of the reversal of C-13 NMR chemical shielding. Careful NMR analysis revealed that sulfur and selenium-centered H-bonds induce a shielding effect on the C-13(C=S(Se)) during the transition from amides to thioamides or selenoamides, with the sigma(11) and sigma(22) components of the isotropic shielding tensor playing a crucial role.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Multidisciplinary
Juan Carlos Fuentes-Monteverde, Markus Noll, Akhi Das, Stefan Immel, Michael Reggelin, Christian Griesinger, Nilamoni Nath
Summary: Anisotropic NMR spectroscopy is a powerful tool for determining the configurations of synthetic and complex natural compounds. In addition to the relative configuration, the deduction of the absolute configuration is also an important goal. Investigating the enantiodiscriminating capabilities of chiral alignment media becomes essential. This study demonstrates the measurement of residual chemical shift anisotropies in chiral liquid crystals, providing valuable insights for determining the configurations of chiral analytes.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Multidisciplinary
Zhaofei Chai, Qiong Wu, Kai Cheng, Xiaoli Liu, Zeting Zhang, Ling Jiang, Xin Zhou, Maili Liu, Conggang Li
Summary: With the introduction of a high-sensitivity tag, proteins can be observed at atomic resolution in their native cellular environment, significantly expanding the scope of protein NMR.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Multidisciplinary
Alexey Sudakov, Bozana Knezic, Martin Hengesbach, Boris Fuertig, Elke Stirnal, Harald Schwalbe
Summary: More than 170 post-transcriptional modifications of RNAs have been identified. However, the detailed investigation of these modifications is limited due to the difficulty in producing large RNAs containing these modifications. This study reports the chemo-enzymatic synthesis of RNA modifications and fluorine-modified analogs, allowing the synthesis of large RNAs. The incorporation of labeled nucleotides in the riboswitch demonstrated the applicability of the modified large RNAs in characterizing RNA fold and dynamics.
CHEMISTRY-A EUROPEAN JOURNAL
(2023)
Article
Biochemical Research Methods
Roy Hoffman
Summary: The study found that the chemical shift of TMS is influenced by solvent and environmental conditions. Therefore, methods for improving measurements were developed, and comparisons of chemical shifts in different solvents were made, showing the effects of polarizability and aromaticity on TMS chemical shift.
JOURNAL OF MAGNETIC RESONANCE
(2022)
Article
Chemistry, Physical
Gerald Platzer, Aleksandra L. Ptaszek, Jark Boettcher, Julian E. Fuchs, Leonhard Geist, Daniel Braun, Darryl B. Mcconnell, Robert Konrat, Pedro A. Sanchez-Murcia, Moriz Mayer
Summary: The availability of high-resolution 3D structural information is vital in the study of guest-host systems in various fields. In drug discovery, this information is routinely used to establish and validate structure-activity relationships. This study highlights the usefulness of ligand H-1 NMR chemical shift information in combination with a QM/MM MD workflow for generating protein-ligand ensembles that accurately reproduce solution structural data.
Article
Chemistry, Physical
Christian Bruns, Rainer Ringleb, Isabell Prediger, Frederike Euchner, Johannes Bernarding, Markus Plaumann
Summary: The interest in fluorinated substances has grown due to their diverse properties. NMR spectroscopy, an important analytical method, provides information on the structure and environment changes. Temperature plays a crucial role in most studies, however, measuring it is challenging in certain cases. Despite the difficulties, the potential applications in chemical reactors and medical fields are significant. Polyfluorinated molecules with separate 19F MR signals prove to be ideal for temperature determination without the need for a reference substance. The sensitivity of temperature is influenced by fluorine position and chemical environment.
Article
Chemistry, Multidisciplinary
Lorenz M. Urner, Ga Young Lee, Joseph W. Treacy, Aneta Turlik, Saeed Khan, K. N. Houk, Michael E. Jung
Summary: The 4-anilino-6,7-ethylenedioxy-5-fluoroquinazoline scaffold is proposed as a novel model system for studying weak NH...F hydrogen bonding interactions, with experimental and theoretical methods used to characterize this interaction. The results demonstrate that fluorine can act as a weak hydrogen bond acceptor, and the strength of the hydrogen bond can be modulated through changes in electron distribution and resonance.
CHEMISTRY-A EUROPEAN JOURNAL
(2022)
Article
Chemistry, Multidisciplinary
Wenkai Zhu, Alex J. Guseman, Fatema Bhinderwala, Manman Lu, Xun-Cheng Su, Angela M. Gronenborn
Summary: In-cell NMR spectroscopy is a powerful tool for studying protein behavior in physiological environments. However, interactions with cellular components can often broaden resonances beyond detection in commonly used H-1-N-15 HSQC spectra of globular proteins. In contrast, F-19 spectra in mammalian cells readily show signals. By using stable, rigid Ln(III) chelate pendants, attached via non-reducible thioether bonds, F-19 paramagnetic relaxation enhancements provide an effective method for accurately assessing protein conformations in cellular milieu.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Physical
Coral Mycroft, Mathias Nilsson, Gareth A. Morris, Laura Castanar
Summary: A general pure shift method is presented for obtaining ultra-high resolution H-1 NMR spectra by suppressing both homonuclear and heteronuclear J-couplings. Its usefulness is demonstrated in the analysis of fluorine- and phosphorus-containing compounds of pharmaceutical and biochemical interest.
Article
Chemistry, Multidisciplinary
Cristina Cabrero, Nerea Martin-Pintado, Stefania Mazzini, Raimundo Gargallo, Ramon Eritja, Anna Avino, Carlos Gonzalez
Summary: Insertion of 2'-deoxy-2',2'-difluorocytidine (dFdC) into a DNA strand or a DNA : RNA hybrid duplex slightly destabilizes the duplex and causes minor local distortions, which are more pronounced in the case of the DNA : RNA hybrid. Analysis of solution structures by NMR shows that dFdC adopts a North sugar conformation in pure DNA, while in DNA : RNA hybrids it adopts a South sugar conformation that facilitates attractive interactions compensating for base pair distortions. These interactions resemble pseudohydrogen bonds found in other nucleic acid structures with fluorine modified sugars.
CHEMISTRY-A EUROPEAN JOURNAL
(2021)
Article
Chemistry, Organic
Helmut Poleschner, Matthias Heydenreich, Andreas J. Achazi
Summary: Trans-cycloalkenes with the X-C=C-SeR*-unit and ring sizes from 9 to 20 have been synthesized. The epimerization of the trans-cycloalkenes, i.e., the 180 degrees rotation of the X-C=C-unit through the cavity of the ring, was studied. The results showed significant effects of ring size and steric effects due to the groups X.
EUROPEAN JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Biochemistry & Molecular Biology
Martin Dracinsky
Summary: This study thoroughly analyzes the large deviations in predicted hydrogen and carbon chemical shifts of a series of solid pyridinium fumarates. The influence of geometry optimization protocol and computational level on the accuracy of predicted chemical shifts is investigated, with improvements suggested for proton chemical-shift predictions through the use of computationally demanding hybrid functional for geometry optimization.
Article
Chemistry, Multidisciplinary
Kosuke Higashida, Fabian Bruning, Nagataka Tsujimoto, Kenya Higashihara, Haruki Nagae, Antonio Togni, Kazushi Mashima
CHEMISTRY-A EUROPEAN JOURNAL
(2020)
Article
Chemistry, Multidisciplinary
Pascal S. Engl, Alexey Tsygankov, Jordan Silva, Jean-Paul Lange, Christophe Coperet, Antonio Togni, Alexey Fedorov
HELVETICA CHIMICA ACTA
(2020)
Editorial Material
Chemistry, Multidisciplinary
Antonio Togni
Article
Chemistry, Multidisciplinary
Dustin Bornemann, Cody Ross Pitts, Lionel Wettstein, Fabian Bruning, Sebastian Kung, Liangyu Guan, Nils Trapp, Hansjorg Grutzmacher, Antonio Togni
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2020)
Article
Chemistry, Multidisciplinary
Jorna Kalim, Thibaut Duhail, Ewa Pietrasiak, Elsa Anselmi, Emmanuel Magnier, Antonio Togni
Summary: A study has discovered a method for direct trifluoromethylation of various aliphatic alcohols using a hypervalent iodosulfoximine reagent, resulting in the efficient synthesis of corresponding ethers.
CHEMISTRY-A EUROPEAN JOURNAL
(2021)
Article
Chemistry, Multidisciplinary
Phil Liebing, Cody Ross Pitts, Marc Reimann, Nils Trapp, David Rombach, Dustin Bornemann, Martin Kaupp, Antonio Togni
Summary: The analysis of crystal structures of SF5- or SF4-containing molecules showed that these groups are often surrounded by hydrogen or other fluorine atoms, and F...F contacts are important in many compounds. Additionally, repeating structural motifs formed by contacts between SF5 groups were identified, including different supramolecular dimers and infinite chains.
CHEMISTRY-A EUROPEAN JOURNAL
(2021)
Article
Chemistry, Multidisciplinary
Markus T. Mueller, Antonio Togni, Carlo Thilgen
Summary: ETH Zurich evaluated the basic chemistry knowledge of first-year students in Chemistry, Biology, Pharmaceutical Sciences, and Health Sciences and Technology disciplines, finding that some students performed better than others, with no significant differences observed between gender or region.
Article
Chemistry, Multidisciplinary
Jordan De Jesus Silva, Niccolo Bartalucci, Benson Jelier, Samantha Grosslight, Tobias Gensch, Claas Schuenemann, Bernd Mueller, Paul C. J. Kamer, Christophe Coperet, Matthew S. Sigman, Antonio Togni
Summary: A novel synthetic method for palladium-catalyzed cyanation of aryl boronic acids using N-cyanosuccinimide has been developed, with high-throughput experimentation identifying key ligand properties that govern reaction yield. The study categorizes ligands into three groups and shows that for monophosphines, sigma-donation, pi-acceptance, and steric effects play important roles in yield improvement. The research demonstrates good functional group tolerance in a wider substrate scope, providing insights for the design of improved palladium cross-coupling catalysts.
HELVETICA CHIMICA ACTA
(2021)
Article
Chemistry, Multidisciplinary
Daniel Abegg, Martin Tomanik, Nan Qiu, Dany Pechalrieu, Anton Shuster, Bruno Commare, Antonio Togni, Seth B. Herzon, Alexander Adibekian
Summary: The tetrafluoroalkyl benziodoxole (TFBX) has emerged as a powerful cysteine-selective chemoproteomic probe, featuring superior target occupancy, faster labeling kinetics, and broader proteomic coverage compared to traditional cysteine-reactive probes. This new probe has been demonstrated to successfully identify cellular targets of (-)-myrocin G, leading to the discovery of the first reported inhibitors of the biomedically important protein XRCC5. Additionally, this probe disrupts the interaction of XRCC5 with DNA, sensitizing cancer cells to chemotherapeutic agents and UV-light-induced DNA damage.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2021)
Review
Chemistry, Multidisciplinary
Yannick Kraemer, Emily Nicole Bergman, Antonio Togni, Cody Ross Pitts
Summary: In the development of synthetic methods, researchers discovered a mild and inexpensive oxidative fluorination method based on potassium fluoride and trichloroisocyanuric acid (TCICA), which enabled the synthesis of pentafluorosulfanyl (SF5) compounds. Further exploration led to the discovery of its application in the synthesis of other fluorinated heteroatoms. Ultimately, it was found that this method can be used to synthesize SF5Cl.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Biochemical Research Methods
Alvar D. Gossert, Gerhard Wider
Summary: We introduce a new spin-state selection method called RODA, which enhances the sensitivity of spin systems with TROSY effect. RODA records the TROSY component of a doublet twice using a double acquisition scheme and adds consecutive NMR signals without requiring any special processing. It can be seamlessly integrated into existing experiments and demonstrates broad applicability in systems with N-15-H-1, F-19-C-13, or H-1-C-13 moieties exhibiting TROSY effect. Furthermore, RODA enables virtual decoupling with increased sensitivity in situations like dissolution DNP.
JOURNAL OF MAGNETIC RESONANCE
(2022)
Article
Multidisciplinary Sciences
Sebastian A. G. Braus, Francesca L. Short, Stefanie Holz, Matthew J. M. Stedman, Alvar D. Gossert, Manuela K. Hospenthal
Summary: The minor pilin FimT plays a crucial role in the natural transformation of bacteria by directly binding to DNA. The results suggest that FimT is important for DNA uptake in a wide range of competent bacterial species.
NATURE COMMUNICATIONS
(2022)
Article
Biochemistry & Molecular Biology
Stefan Schuetz, Christian Bergsdorf, Benedikt Goretzki, Andreas Lingel, Martin Renatus, Alvar D. Gossert, Wolfgang Jahnke
Summary: This study utilizes Nuclear Magnetic Resonance (NMR) spectroscopy and Surface Plasmon Resonance (SPR) to investigate the interactions between the proteins MYC and MAX, and their roles in regulating cellular processes.
JOURNAL OF MOLECULAR BIOLOGY
(2022)
Article
Chemistry, Multidisciplinary
Feng-Jie Wu, Pascal S. Rieder, Layara Akemi Abiko, Philip Roessler, Alvar D. Gossert, Daniel Haeussinger, Stephan Grzesiek
Summary: The method presented in this study utilizes antibodies tagged with lanthanoid DOTA chelators to efficiently assign nuclei of biomacromolecules, providing insights into their chemical shift changes during functional dynamics.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2022)
Review
Chemistry, Physical
Claudio Dalvit, Isabel Gmur, Philip Robler, Alvar D. Gossert
Summary: NMR spectroscopy is widely used for hit identification, but its use in determining the dissociation constant of tight binders is limited. This article provides a theoretical analysis and practical guidelines for determining the binding affinity of strong ligands using NMR experiments. Various methods are discussed, with emphasis on general approaches like competition experiments.
PROGRESS IN NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY
(2023)