A5076633044- Advanced NMR Techniques and Applications
- Electron Spin Resonance Studies
- Solid-state spectroscopy and crystallography
- Crystallization and Solubility Studies
- X-ray Diffraction in Crystallography
- Supramolecular Chemistry and Complexes
- Nitric Oxide and Endothelin Effects
- Cancer, Hypoxia, and Metabolism
- Lanthanide and Transition Metal Complexes
- Molecular Sensors and Ion Detection
- Magnetism in coordination complexes
- Analytical Chemistry and Sensors
- Crystallography and molecular interactions
- Metabolism, Diabetes, and Cancer
- Muon and positron interactions and applications
- Mitochondrial Function and Pathology
- Molecular spectroscopy and chirality
- Atomic and Subatomic Physics Research
- Photochemistry and Electron Transfer Studies
- Metal-Organic Frameworks: Synthesis and Applications
- NMR spectroscopy and applications
- Redox biology and oxidative stress
- Free Radicals and Antioxidants
- Photoreceptor and optogenetics research
- Luminescence and Fluorescent Materials
Aix-Marseille Université
2016-2025
Institut de Chimie Radicalaire
2016-2025
Centre National de la Recherche Scientifique
2015-2024
Université Sorbonne Paris Nord
2021
Réseau sur le Stockage Electrochimique de l'énergie
2020
École Polytechnique Fédérale de Lausanne
2020
Robert Bosch (Germany)
2019
Délégation Provence et Corse
2014-2018
Laboratoire de Chimie
2002-2017
Bruker (United States)
2010
Well polarized: Two new polarizing agents PyPol and AMUPol soluble in glycerol/water mixtures are used for dynamic nuclear polarization (DNP) NMR spectroscopy. The enhancement factors (ε) about 3.5 to 4 times larger than the established agent TOTAPOL at 263 395 GHz. For AMUPol, temperature dependence of ε allows DNP experiments be performed temperatures significantly higher typical high-field experiments. As a service our authors readers, this journal provides supporting information supplied...
A series of seven functionalized nitroxide biradicals (the bTbK biradical and six derivatives) are investigated as exogenous polarization sources for dynamic nuclear (DNP) solid-state NMR at 9.4 T with ca. 100 K sample temperatures. The impact electron relaxation times on the DNP enhancement (ε) is examined, we observe that longer inversion recovery phase memory provide larger ε. All radicals tested in both bulk 1,1,2,2-tetrachloroethane solutions mesoporous materials, difference ε between...
A new polarizing agent with superior performance in dynamic nuclear polarization experiments is introduced, and utilizes two TEMPO (2,2,6,6-tetramethylpiperidine-1-oxyl) moieties connected through a rigid spiro tether (see structure). The observed NMR signal intensities were enhanced by factor of 1.4 compared to those TOTAPOL, previously described TEMPO-based biradical flexible tether.
Lung cancer often has a poor prognosis, with brain metastases major reason for mortality. We modified lonidamine (LND), an antiglycolytic drug limited efficacy, to mitochondria-targeted mito-lonidamine (Mito-LND) which is 100-fold more potent. Mito-LND, tumor-selective inhibitor of oxidative phosphorylation, inhibits mitochondrial bioenergetics in lung cells and mitigates cell viability, growth, progression, metastasis xenografts mice. Mito-LND blocks tumor development by inhibiting...
Abstract Metformin (Met) is an approved antidiabetic drug currently being explored for repurposing in cancer treatment based on recent evidence of its apparent chemopreventive properties. Met weakly cationic and targets the mitochondria to induce cytotoxic effects tumor cells, albeit not very effectively. We hypothesized that increasing mitochondria-targeting potential by attaching a positively charged lipophilic substituent would enhance antitumor activity Met. In pursuit this question, we...
A new nitroxide-based biradical having a long electron spin-lattice relaxation time (T(1e)) has been developed as an exogenous polarization source for DNP solid-state NMR experiments. The performance of this is demonstrated on hybrid silica-based mesostructured materials impregnated with 1,1,2,2-tetrachloroethane radical containing solutions, well in frozen bulk yielding enhancement factors (ε) over 100 at magnetic field 9.4 T and sample temperatures ~100 K. effects concentration the overall...
A matter of minutes: Dynamic nuclear polarization (DNP) is applied to enhance the signal solid-state NMR spectra metal–organic framework (MOF) materials. The enhancement enables acquisition high-quality 1D 13C spectra, 2D 1H–13C dipolar HETCOR and 15N with natural isotopic abundance in experiment times on order minutes. MW=microwaves. Detailed facts importance specialist readers are published as ”Supporting Information”. Such documents peer-reviewed, but not copy-edited or typeset. They made...
Herein we describe a high-throughput fluorescence and HPLC-based methodology for global profiling of reactive oxygen nitrogen species (ROS/RNS) in biological systems. The combined use HPLC detection is key to successful implementation validation this methodology. Included here are methods specifically detect quantitate the products formed from interaction between ROS/RNS fluorogenic probes, as follows: superoxide using hydroethidine, peroxynitrite boronate-based nitric oxide-derived...
A series of non-aqueous solvents combined with the exogenous biradical bTbK are developed for DNP NMR that yield enhancements comparable to best available water based systems. 1,1,2,2-tetrachloroethane appears be one most promising organic solid-state NMR. Here this results in a reduction experimental times by factor 1000. These new demonstrated first surface enhanced characterization an organometallic complex supported on hydrophobic surface.
A series of 37 dinitroxide biradicals have been prepared and their performance studied as polarizing agents in cross-effect DNP NMR experiments at 9.4 T 100 K 1,1,2,2-tetrachloroethane (TCE).
Dynamic nuclear polarization (DNP) solid-state magnetic resonance (NMR) has developed into an invaluable tool for the investigation of a wide range materials. However, sensitivity gain achieved with many polarizing agents suffers from unfavorable field and magic angle spinning (MAS) frequency dependence. We present series new hybrid biradicals, soluble in organic solvents, that consist isotropic narrow electron paramagnetic line radical, α,γ-bisdiphenylene-β-phenylallyl (BDPA), tethered to...
There is currently great interest in understanding the limits on NMR signal enhancements provided by dynamic nuclear polarization (DNP), and particular if theoretical maximum can be achieved. We show that over a 2-fold improvement cross-effect DNP achieved MAS experiments frozen solutions simply incorporating solid particles into sample. At 9.4 T ∼105 K, up to εH = 515 are obtained this way, corresponding 78% of maximum. also underline degassing sample important achieve highest enhancements....
Efficient dynamic nuclear polarization (DNP) in solids, which enables very high sensitivity NMR experiments, is currently limited to temperatures of around 100 K and below. Here we show how by choosing an adequate solvent, (1)H cross effect DNP enhancements over 80 can be obtained at 240 K. To achieve this use the biradical TEKPol dissolved a glassy phase ortho-terphenyl (OTP). We study solvent enhancement both BDPA OTP range from 300 9.4 18.8 T. Surprisingly, find that decreases only...
Approaching protein structural dynamics and protein-protein interactions in the cellular environment is a fundamental challenge. Owing to its absolute sensitivity selectivity paramagnetic species, site-directed spin labeling (SDSL) combined with electron resonance (EPR) has potential evolve into an efficient method follow conformational changes proteins directly inside cells. Until now, use of nitroxide-based labels for in-cell studies represented major hurdle because their short persistence...
We describe a photochemical method to introduce single alcohol function directly on cucurbit[n]urils (n = 5, 6, 7, 8) with conversions of the order 95-100% using hydrogen peroxide and UV light. The reaction was easily scaled up 1 g for CB[6] CB[7]. Spin trapping cucurbituril radicals combined MS experiments allowed us get insights about mechanism characterize CB[5], CB[6], CB[7], CB[8] monofunctional compounds. Experiments involving (18)O isotopically labeled water indicated that complex...
TinyPol binitroxides provide significantly higher DNP enhancement factors for solid-state NMR spectroscopy at high magnetic fields than today's reference radical AMPUPol.
Novel multifunctional tacrines for Alzheimer's disease were obtained by Ugi-reaction between ferulic (or lipoic acid), a melatonin-like isocyanide, formaldehyde, and tacrine derivatives, according to the antioxidant additive approach in order modulate oxidative stress as therapeutic strategy. Compound 5c has been identified promising permeable agent showing excellent properties, strong cholinesterase inhibitory activity, less hepatotoxicity than tacrine, best neuroprotective capacity, being...
Solid-state nuclear magnetic resonance under magic angle spinning (MAS) enhanced with dynamic polarization (DNP) is a powerful approach to characterize many important classes of materials, allowing access previously inaccessible structural and parameters. Here, we present the first DNP MAS experiments using 0.7 mm probe, which allows us reach frequencies 65 kHz, microwave irradiation, at 100 K. At highest field available for today (21.1 T), find that polarizing agent HyTEK2 provides...
The combined effects of the cellular environment on proteins led to definition a fifth level protein structural organization termed quinary structure. To explore implication potential structure for globular proteins, we studied dynamics and conformations Escherichia coli (E. coli) peptidyl-prolyl cis/trans isomerase B (PpiB) in E. cells. PpiB plays major role maturation regulation folded by catalyzing isomerization proline imidic peptide bond. We applied electron paramagnetic resonance (EPR)...