Article
Chemistry, Organic
Clement A. Sanchez, Charlene Gadais, Gregory Chaume, Sylvaine Girard, Evelyne Chelain, Thierry Brigaud
Summary: The straightforward synthesis of enantiopure 5-(R)-and 5-(S)-trifluoromethylproline involves key steps such as Ruppert-Prakash reagent addition on L-pyroglutamic esters, followed by an elimination reaction and a selective reduction. The solution-phase and solid-phase incorporation of this unprotected enantiopure fluorinated amino acid in a short peptide chain was demonstrated. Compared to proline, the CF3 group provides a decrease of the trans to cis amide bond isomerization energy and an increase of the cis conformer population.
Article
Chemistry, Multidisciplinary
Jan H. Overbeck, Jennifer Vogele, Felix Nussbaumer, Elke Duchardt-Ferner, Christoph Kreutz, Jens Wohnert, Remco Sprangers
Summary: The synthetic neomycin-sensing riboswitch interacts with neomycin, ribostamycin, and paromomycin. However, only neomycin can efficiently repress translation initiation due to differences in ligand:riboswitch dynamics. Five complementary fluorine-based NMR methods were used to accurately quantify dynamics in the riboswitch complexes and identified four structurally different states. These findings highlight the potential of F-19 NMR methods in characterizing complex exchange processes.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Biochemistry & Molecular Biology
Lucrezia Cosottini, Stefano Zineddu, Lara Massai, Veronica Ghini, Paola Turano
Summary: In this study, we present a method to efficiently produce 5-F-Trp human H ferritin by selectively incorporating 19F into the side chain of W93 using 5-fluoroindole as the fluorinated precursor. Human H ferritin is a nanocage composed of 24 identical subunits, each containing a single Trp exposed on the external surface. The incorporation of 5-F-Trp allows for the study of intermolecular interactions and monitoring of ferritin uptake by cells, which has important applications in drug delivery.
JOURNAL OF INORGANIC BIOCHEMISTRY
(2023)
Article
Chemistry, Multidisciplinary
Patrick M. Killoran, George S. M. Hanson, Sanne J. M. Verhoork, Madeleine Smith, Davide Del Gobbo, Lu-Yun Lian, Christopher R. Coxon
Summary: A method using 4-fluorophenylalanine as a reporter group for F-19 NMR was developed to measure the conformational status of peptidylprolyl bonds in peptide models. This method was applied to study the prolyl bond status in pentapeptide models of the intrinsically disordered region of alpha-synuclein. It was demonstrated that F-19 NMR is a valuable tool for studying proline isomerism under different conditions.
CHEMISTRY-A EUROPEAN JOURNAL
(2023)
Article
Chemistry, Multidisciplinary
Fanni Sebak, Peter Ecsedi, Wolfgang Bermel, Burkhard Luy, Laszlo Nyitray, Andrea Bodor
Summary: This study introduces two new NMR experiments to identify proline cis/trans isomers in proteins, detecting minor conformers present in 4-15%, and analyzes the impact of CK2 phosphorylation on the cis/trans-proline equilibrium. Statistical analysis indicates that the amino acid type also affects the distribution of cis/trans-proline.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Multidisciplinary
Bridget Tang, Katie Chong, Arthur J. J. Ragauskas, Robert Evans
Summary: Pyrolysis bio-oils, derived from lignocellulosic biomass pyrolysis, have potential as widely-used fuels. These oils have complex chemical compositions containing hundreds to thousands oxygen-containing compounds with diverse physical properties, chemical structures, and concentrations. Knowledge of bio-oil composition is essential for optimizing pyrolysis processes and subsequent fuel upgrading. This study successfully used benchtop nuclear magnetic resonance (NMR) spectrometers to analyze pyrolysis oils, showing comparable results to titrations for total carbonyl content. The benchtop NMR spectrometer also detected important spectral features and quantified different carbonyl groups without the need for cryogens, making NMR analysis of pyrolysis oils more accessible to various users.
Review
Chemistry, Physical
Tapas Guchhait, Lipsita Panda, Sushree Prajna Rout, Monalisa Giri
Summary: This study focuses on the exchange process between proton and deuterium isotopes within the molecule of anion receptors, with particular emphasis on the proton to deuterium (1H -> 2D) exchange facilitated by fluoride ion. Both 1H NMR and 19F NMR spectroscopy are useful for monitoring the exchange studies, but 19F NMR spectroscopy provides more detailed information than 1H NMR spectroscopy. Therefore, the 19F NMR spectroscopic method is important for investigating the solution state structural behavior of fluoride ion complexes. This study also investigates the exchangeable protons in various types of anion receptors, providing direct evidence of sequential substitution of protons with deuterium atoms in solvent molecules. (c) 2023 Elsevier B.V. All rights reserved.
JOURNAL OF MOLECULAR STRUCTURE
(2023)
Article
Chemistry, Multidisciplinary
Yun Huang, Krishna D. Reddy, Clay Bracken, Biao Qiu, Wenhu Zhan, David Eliezer, Olga Boudker
Summary: Limited chemical shift dispersion presents a challenge in studying multistate equilibria of large membrane proteins using 19F NMR. A novel monofluoroethyl 19F probe is introduced to significantly increase the chemical shift dispersion. The improved sensitivity and line shape enable the detection of previously unresolved states in one-dimensional (1D) 19F NMR spectra of a 134 kDa membrane transporter. These states' population changes correlate with conformational changes observed in structural ensembles determined by single-particle cryo-electron microscopy (cryo-EM), indicating the potential of 19F NMR in guiding sample preparation and facilitating image analysis and 3D classification.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Biochemistry & Molecular Biology
Fanni Sebak, Janos Szolomajer, Nandor Papp, Gabor K. Toth, Andrea Bodor
Summary: The type of neighboring amino acids, especially aromatic and positively charged sidechains, has been found to affect the cis-Pro content. These findings can assist in the design of protein regions with specific cis-Pro content and contribute to a better understanding of the roles and functions of IDPs.
FRONTIERS IN BIOSCIENCE-LANDMARK
(2023)
Article
Biochemical Research Methods
Patrick G. Isenegger, Brian Josephson, Ben Gaunt, Matthew J. Davy, Veronique Gouverneur, Andrew J. Baldwin, Benjamin G. Davis
Summary: This article describes a robust, mild and fast method for the posttranslational, site-directed fluorination of protein sidechains, which can be detected by F-19-based magnetic resonance methods. This chemical editing method is stable, mild, fast and highly efficient, and can be used by non-experts to prepare fluorinated proteins within 24 hours without the need for bespoke biological systems.
Article
Chemistry, Analytical
Alen Albreht, Humma Hussain, Beatriz Jimenez, Ada H. Y. Yuen, Luke Whiley, Matthias Witt, Matthew R. Lewis, Elena Chekmeneva
Summary: Liquid chromatography-mass spectrometry (LC-MS) is widely used in metabolomics to analyze complex biological samples. However, interference signals are often observed in LC-MS metabolic profiles. In this study, two interfering metabolites, L,L-TMAP and L,L-DMPP, were identified and their chemical and spectroscopic characteristics were analyzed. Proposed strategies to mitigate interference effects include modifying column temperature and pH, as well as sample dilution and internal standardization methods.
ANALYTICAL CHEMISTRY
(2022)
Article
Chemistry, Multidisciplinary
Qiong Wu, Xiaoli Liu, Zhaofei Chai, Kai Cheng, Guohua Xu, Ling Jiang, Maili Liu, Conggang Li
Summary: This study reports the conformation and interaction of a newly discovered lanthanide ion binding protein, LanM, with Ln(3+) in Escherichia coli cells using in-cell NMR technique. It was found that LanM remains unfolded and fails to bind Ln(3+) due to the abundance of phosphate groups in Escherichia coli cells.
CHEMICAL COMMUNICATIONS
(2022)
Article
Chemistry, Multidisciplinary
Sara M. A. Pinto, Ana R. R. Ferreira, Daniela S. S. Teixeira, Sandra C. C. Nunes, Ana L. M. Batista de Carvalho, Joseany M. S. Almeida, Zoltan Garda, Agnes Pallier, Alberto A. C. C. Pais, Christopher M. A. Brett, Eva Toth, Maria P. M. Marques, Mariette M. M. Pereira, Carlos F. G. C. Geraldes
Summary: A new fluorinated manganese porphyrin, (Mn-TPP-p-CF3), is capable of providing dual H-1 relaxivity and F-19 NMR response to redox changes based on the Mn(III)/Mn(II) equilibrium. The properties of H-1 relaxometry and F-19 NMR make it suitable for the detection of differential redox MRI. The physical-chemical characterization shows that the Mn(III)-F distance is well tailored to allow for adequate paramagnetic effect on F-19 T-1 and T-2 relaxation times.
CHEMISTRY-A EUROPEAN JOURNAL
(2023)
Article
Chemistry, Physical
Yang Lu, Mingming Sun, Ning Xi
Summary: In di-ortho-F substituted N-phenyl gamma-lactams, covalently identical ortho-F nuclei exhibit dual 19F NMR signals. The deshielding 19F signal (delta down) is significantly influenced by C9-substituent, particularly when C9-substituents are steric bulky. Notably, the deshielded 19F chemical shift is sensitive to chirality variations at C9-alkyls, while the shielded 19F NMR signal delta up shows negligible changes among various C9-alkyl derivatives. Calculated molecular electrostatic surface potentials (ESPs) were used to explain the experimental observations. 19F NMR signal assignments in an exemplary rotameric molecule are provided based on the understanding of the structure-19F shielding relationship. Our work lays the foundation for deciphering 19F shielding in biologically important molecules and drugs, as well as utilizing 19F chemical shifts to monitor molecular dynamics and conformations.
JOURNAL OF MOLECULAR STRUCTURE
(2023)
Article
Chemistry, Multidisciplinary
Jack E. Bramham, Alexander P. Golovanov
Summary: This study demonstrates a new sample illumination device that allows users to perform in situ photo-NMR experiments easily. By placing an LED array directly at the top of a special sample tube, the device solves the challenge of illuminating NMR samples deep within the bore of a spectrometer magnet. The setup shows potential for studying a wide range of light-dependent chemical and biological phenomena.
COMMUNICATIONS CHEMISTRY
(2022)
Review
Chemistry, Multidisciplinary
Dan He, Yawen Li, Fuwen Zhao, Yuze Lin
Summary: High trap density in organic solar cells leads to localized charge carriers and reduced carrier lifetime, limiting device efficiency. This feature article summarizes the recent advances of trap suppression by material design and device engineering.
CHEMICAL COMMUNICATIONS
(2024)
Review
Chemistry, Multidisciplinary
Olivier Monfort, Arshitha Madhusudhan, Martin Motola
Summary: This article presents the advantages of coupling photocatalysis and Fenton-based processes for environmental remediation and discusses their synergy. It critically examines the simultaneous triggering of these two processes and provides insights into research approaches. The study aims to enhance understanding of this complex process and highlight the potential integration of new catalysts in current wastewater treatment technology.
CHEMICAL COMMUNICATIONS
(2024)
Article
Chemistry, Multidisciplinary
Manideepa Dhar, Chittaranjan Mishra, Avijit Das, Uttam Manna
Summary: An approach of 'polymerization of monomers in its aggregated form' has been introduced to tailor the water wettability of fibrous and porous substrates, achieving hydrophobicity to superhydrophobicity transition, as well as patterned wettability. This facile chemical method provides a durable coating with adjustable and patterned wettability for various potential applications.
CHEMICAL COMMUNICATIONS
(2024)
Article
Chemistry, Multidisciplinary
Saswat Ranjan Bhoi, Chhanda Debnath, Shikha Gandhi
Summary: In this article, a novel catalytic reaction using Pd(0) and Bronsted acid is reported for the synthesis of biologically important imidazolidinone-fused N-heterocycles through redox-neutral intramolecular N-allylation of indoles and pyrroles with alkynes. This atom-economical method is applicable to a wide range of substrates and eliminates the need for leaving groups or oxidizing agents commonly used in traditional allylation reactions.
CHEMICAL COMMUNICATIONS
(2024)
Article
Chemistry, Multidisciplinary
Longkun Chen, Mingshuai Zhang, Meichen Liu, Zhuoyuan Liu, Yuetong Qiu, Zhilai Zhang, Fuchao Yu, Jiuzhong Huang
Summary: In this study, an efficient Rh(III)-catalyzed selective mono- and dual-C-H bond functionalization/cyclization with iodonium ylide as the sole coupling partner was demonstrated. Fused benzodiazepine skeletons were obtained in excellent yields, providing an improved approach to dual C-H unsymmetrical functionalization.
CHEMICAL COMMUNICATIONS
(2024)
Article
Chemistry, Multidisciplinary
Alice Kennett, Sven Epple, Gabriella van der Valk, Irene Georgiou, Evelyne Gout, Romain R. Vives, Angela J. Russell
Summary: This study presents the design and synthesis of sulfated disaccharide inhibitors based on IdoA(2S)-GlcNS(6S), which showed potent inhibition of Sulf-2. The results suggest that IdoA(2S)-GlcNS(6S) is the shortest fragment size required for effective inhibition of Sulfs, and a trisulfated disaccharide is identified as the minimal fragment size of heparan sulfate for effective endosulfatase inhibition.
CHEMICAL COMMUNICATIONS
(2024)
Article
Chemistry, Multidisciplinary
Mauro Garbini, Andrea Brunetti, Riccardo Pedrazzani, Magda Monari, Massimo Marcaccio, Giulio Bertuzzi, Marco Bandini
Summary: The self-adaptability of galvanostatic electrolysis was found to be helpful in a multistage chemo- and diastereoselective electrochemically promoted cyclodimerization of chalcones. Through a series of reductive events, densely functionalized cyclopentanes with five contiguous stereocenters were obtained (25 examples, yields up to 95%, dr values up to >20:1). Further experimental and electrochemical investigations indicated the crucial role of dynamic kinetic resolution of the aldol intermediate in the reaction mechanism.
CHEMICAL COMMUNICATIONS
(2024)
Article
Chemistry, Multidisciplinary
Dhananjay S. Nipate, Neha Meena, Prakash N. Swami, Krishnan Rangan, Anil Kumar
Summary: In this study, the synthesis of functionalized benzo[a]phenazines and indazolo[2,3-a]quinolines was achieved through Rh(III)-catalyzed oxidative annulation of 2-arylquinoxalines and 2-aryl-2H-indazoles with allyl alcohols. The method showed a wide substrate scope, excellent functional group tolerance, good to high yields of annulated products, and the capability for scaled-up synthesis. A tentative mechanism of the annulation reaction was proposed based on a preliminary mechanistic investigation.
CHEMICAL COMMUNICATIONS
(2024)
Article
Chemistry, Multidisciplinary
Ruonan Zhang, Abudukadi Tudi, Xia Yang, Xuping Wang, Zhihua Yang, Shujuan Han, Shilie Pan
Summary: A new lead tellurium borate material with a unique fundamental building block [B4O10] was synthesized and found to exhibit high birefringence. The structure-property relationship was discussed using first-principles calculations.
CHEMICAL COMMUNICATIONS
(2024)
Article
Chemistry, Multidisciplinary
Amresh Kumar Singh, Baishali Thakurta, Anupam Giri, Monalisa Pal
Summary: This study introduces three key concepts for the quick synthesis of large-scale high-quality 2D materials films and their utilization in device fabrication.
CHEMICAL COMMUNICATIONS
(2024)
Article
Chemistry, Multidisciplinary
Reina Hagiwara, Shun Nishimura, Kosuke Okeyoshi
Summary: A copolymer-conjugated nanocatalytic system has been developed to improve electron transfer and enhance photoinduced H2 generation.
CHEMICAL COMMUNICATIONS
(2024)