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1. Association of NQO2 With UDP-Glucuronosyltransferases Reduces Menadione Toxicity in Neuroblastoma Cells

Author: Monivan Chhour, Pierre Perio, Regis Gayon, Hélène Ternet-Fontebasso, Gilles Ferry, Françoise Nepveu, Jean A. Boutin, Jan Sudor, and Karine Reybier
Subjects: NQO2, UGT1A6, conjugation, glucuronide, menadiol, cellular toxicity, Therapeutics. Pharmacology, RM1-950
Abstract: The balance between detoxification and toxicity is linked to enzymes of the drug metabolism Phase I (cytochrome P450 or oxidoreductases) and phase II conjugating enzymes (such as the UGTs). After the reduction of quinones, the product of the reaction, the quinols—if not conjugated—re-oxidizes spontaneously to form the substrate quinone with the concomitant production of the toxic reactive oxygen species (ROS). Herein, we documented the modulation of the toxicity of the quinone menadione on a genetically modified neuroblastoma model cell line that expresses both the quinone oxidoreductase 2 (NQO2, E.C. 1.10.5.1) alone or together with the conjugation enzyme UDP-glucuronosyltransferase (UGT1A6, E.C. 2.4.1.17), one of the two UGT isoenzymes capable to conjugate menadione. As previously shown, NQO2 enzymatic activity is concomitant to massive ROS production, as previously shown. The quantification of ROS produced by the menadione metabolism was probed by electron-paramagnetic resonance (EPR) on cell homogenates, while the production of superoxide was measured by liquid chromatography coupled to mass spectrometry (LC-MS) on intact cells. In addition, the dysregulation of the redox homeostasis upon the cell exposure to menadione was studied by fluorescence measurements. Both EPR and LCMS studies confirmed a significant increase in the ROS production in the NQO2 overexpressing cells due to the fast reduction of quinone into quinol that can re-oxidize to form superoxide radicals. However, the effect of NQO2 inhibition was drastically different between cells overexpressing only NQO2 vs. both NQO2 and UGT. Whereas NQO2 inhibition decreases the amount of superoxide in the first case by decreasing the amount of quinol formed, it increased the toxicity of menadione in the cells co-expressing both enzymes. Moreover, for the cells co-expressing QR2 and UGT the homeostasis dysregulation was lower in presence of menadione than for the its counterpart expressing only QR2. Those results confirmed that the cooperation of the two enzymes plays a fundamental role during the cells’ detoxification process. The fluorescence measurements of the variation of redox homeostasis of each cell line and the detection of a glucuronide form of menadiol in the cells co-expressing NQO2 and UGT1A6 enzymes further confirmed our findings.
Published: 2021
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2. Effect of Artemisinin-Loaded Mesoporous Cerium-Doped Calcium Silicate Nanopowder on Cell Proliferation of Human Periodontal Ligament Fibroblasts

Author: Ioannis Tsamesidis, Dimitrios Gkiliopoulos, Georgia K. Pouroutzidou, Evgenia Lymperaki, Chrysanthi Papoulia, Karine Reybier, Pierre Perio, Konstantinos M. Paraskevopoulos, Eleana Kontonasaki, and Anna Theocharidou
Subjects: mesoporous nanopowders, cerium doping, artemisinin loading, hemocompatibility, human periodontal ligament fibroblasts, Chemistry, QD1-999
Abstract: Ion doping has rendered mesoporous structures important materials in the field of tissue engineering, as apart from drug carriers, they can additionally serve as regenerative materials. The purpose of the present study was the synthesis, characterization and evaluation of the effect of artemisinin (ART)-loaded cerium-doped mesoporous calcium silicate nanopowders (NPs) on the hemocompatibility and cell proliferation of human periodontal ligament fibroblasts (hPDLFs). Mesoporous NPs were synthesized in a basic environment via a surfactant assisted cooperative self-assembly process and were characterized using Scanning Electron Microscopy (SEM), X-ray Fluorescence Spectroscopy (XRF), Fourier Transform Infrared Spectroscopy (FT-IR), X-ray Diffraction Analysis (XRD) and N2 Porosimetry. The loading capacity of NPs was evaluated using Ultrahigh Performance Liquid Chromatography/High resolution Mass Spectrometry (UHPLC/HRMS). Their biocompatibility was evaluated with the MTT assay, and the analysis of reactive oxygen species was performed using the cell-permeable ROS-sensitive probe 2′,7′-dichlorodihydrofluorescein diacetate (H2DCFDA). The synthesized NPs presented a mesoporous structure with a surface area ranging from 1312 m2/g for undoped silica to 495 m2/g for the Ce-doped NPs, excellent bioactivity after a 1-day immersion in c-SBF, hemocompatibility and a high loading capacity (around 80%). They presented ROS scavenging properties, and both the unloaded and ART-loaded NPs significantly promoted cell proliferation even at high concentrations of NPs (125 μg/mL). The ART-loaded Ce-doped NPs with the highest amount of cerium slightly restricted cell proliferation after 7 days of culture, but the difference was not significant compared with the control untreated cells.
Published: 2021
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3. Effect of Artemisinin-Loaded Mesoporous Cerium-Doped Calcium Silicate Nanopowder on Cell Proliferation of Human Periodontal Ligament Fibroblasts

Author: Anna Theocharidou, Dimitrios Gkiliopoulos, Karine Reybier, Pierre Perio, Georgia K. Pouroutzidou, Konstantinos M. Paraskevopoulos, Eleana Kontonasaki, Chrysanthi Papoulia, Evgenia Lymperaki, and Ioannis Tsamesidis
Subjects: inorganic chemicals, Biocompatibility, Scanning electron microscope, General Chemical Engineering, technology, industry, and agriculture, chemistry.chemical_element, mesoporous nanopowders, hemocompatibility, Article, chemistry.chemical_compound, Cerium, Chemistry, chemistry, human periodontal ligament fibroblasts, Calcium silicate, General Materials Science, MTT assay, cerium doping, Fourier transform infrared spectroscopy, artemisinin loading, Drug carrier, Mesoporous material, QD1-999, Nuclear chemistry
Abstract: Ion doping has rendered mesoporous structures important materials in the field of tissue engineering, as apart from drug carriers, they can additionally serve as regenerative materials. The purpose of the present study was the synthesis, characterization and evaluation of the effect of artemisinin (ART)-loaded cerium-doped mesoporous calcium silicate nanopowders (NPs) on the hemocompatibility and cell proliferation of human periodontal ligament fibroblasts (hPDLFs). Mesoporous NPs were synthesized in a basic environment via a surfactant assisted cooperative self-assembly process and were characterized using Scanning Electron Microscopy (SEM), X-ray Fluorescence Spectroscopy (XRF), Fourier Transform Infrared Spectroscopy (FT-IR), X-ray Diffraction Analysis (XRD) and N2 Porosimetry. The loading capacity of NPs was evaluated using Ultrahigh Performance Liquid Chromatography/High resolution Mass Spectrometry (UHPLC/HRMS). Their biocompatibility was evaluated with the MTT assay, and the analysis of reactive oxygen species was performed using the cell-permeable ROS-sensitive probe 2′,7′-dichlorodihydrofluorescein diacetate (H2DCFDA). The synthesized NPs presented a mesoporous structure with a surface area ranging from 1312 m2/g for undoped silica to 495 m2/g for the Ce-doped NPs, excellent bioactivity after a 1-day immersion in c-SBF, hemocompatibility and a high loading capacity (around 80%). They presented ROS scavenging properties, and both the unloaded and ART-loaded NPs significantly promoted cell proliferation even at high concentrations of NPs (125 μg/mL). The ART-loaded Ce-doped NPs with the highest amount of cerium slightly restricted cell proliferation after 7 days of culture, but the difference was not significant compared with the control untreated cells.
Published: 2021

4. The Clitocybins and 2-Substituted-Isoindolin-1-Ones: Synthesis and in Vitro Antimycobacterial Activities

Author: Ennaji Najahi, Pierre Perio, Etienne Hollande, Françoise Nepveu, Rym Abidi, Amani Mejai, Maria Rosalia Pasca, and Nambinina V. Rakotoarivelo
Subjects: 0301 basic medicine, medicine.drug_class, Chemistry, Chemical structure, 030106 microbiology, Antimycobacterial, Medicinal chemistry, In vitro, 03 medical and health sciences, Minimum inhibitory concentration, 0302 clinical medicine, Mycobacterium tuberculosis H37Rv, medicine, Vero cell, 030212 general & internal medicine, Cytotoxicity
Abstract: Despite strong indications of antimycobacterial activities for clitocybins reported since 1945, no reports linking chemical structure and activity have been reported in the literature since then. In this study, we synthesized some clitocybin derivatives (also called 2-substituted-isoindolinones), and tested their activities and carried out some chemical derivations. Isoindolinones were prepared from methyl 2-formyl-3,5-dimethoxybenzoate and various primary aromatic amines. Compounds were evaluated for in vitro activity against Mycobacterium tuberculosis H37Rv, as well as for cytotoxicity (CC50) on the Vero cell line. 4,6-dihydroxy-2-(4-hydroxyphenyl)isoindolin-1-one, 7, and 4-hydroxy-2-(4-hydroxyphenyl)-6-methoxy-isoindol-1-one, 5, exhibited the highest antimycobacterial activities (minimum inhibitory concentration = 19.45 µM and 18.45 µM, respectively) and were non-toxic (CC50 = 30 µM and 29 µM, respectively).
Published: 2019

5. Superoxide: A major role in the mechanism of action of essential antimalarial drugs

Author: Karine Reybier, Pierre Perio, Chinedu O. Egwu, Ioannis Tsamesidis, Jean-Michel Augereau, Françoise Benoit-Vical, Pharmacochimie et Biologie pour le Développement (PHARMA-DEV), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie de Toulouse (ICT-FR 2599), Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut de Chimie du CNRS (INC)-Institut de Recherche pour le Développement (IRD), Alex Ekwueme Federal University Ndufu-Alike, Ikwo (AE-FUNAI), Laboratoire de chimie de coordination (LCC), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie de Toulouse (ICT-FR 2599), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Institut de pharmacologie et de biologie structurale (IPBS), Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées, New Antimalarial Molecules and Pharmacological Approaches (ERL1289), Centre d'investigation clinique de Toulouse (CIC 1436), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-CHU Toulouse [Toulouse]-Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-CHU Toulouse [Toulouse]-Institut National de la Santé et de la Recherche Médicale (INSERM), Institut de Recherche pour le Développement (IRD)-Institut de Chimie de Toulouse (ICT), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT), Institut de Chimie de Toulouse (ICT), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS), Université de Toulouse (UT)-Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Pôle Santé publique et médecine publique [CHU Toulouse], Centre Hospitalier Universitaire de Toulouse (CHU Toulouse)-Centre Hospitalier Universitaire de Toulouse (CHU Toulouse)-Université Toulouse III - Paul Sabatier (UT3), Centre Hospitalier Universitaire de Toulouse (CHU Toulouse)-Centre Hospitalier Universitaire de Toulouse (CHU Toulouse), and ANR-16-CE35-0003,INMAR,Réseau intégré des mécanismes de quiescence & clairance impliqués dans la résistance à l'artémisinine chez Plasmodium(2016)
Subjects: 0301 basic medicine, Artemisinins, medicine.medical_treatment, Plasmodium falciparum, Drug Resistance, Dihydroartemisinin, Pharmacology, Mechanism of action, Biochemistry, 03 medical and health sciences, chemistry.chemical_compound, Antimalarials, 0302 clinical medicine, Superoxides, Chloroquine, Physiology (medical), parasitic diseases, medicine, [CHIM.COOR]Chemical Sciences/Coordination chemistry, Artemisinin, biology, Superoxide radicals, Superoxide, biology.organism_classification, 3. Good health, LC-MS, 030104 developmental biology, chemistry, medicine.symptom, Drugs, Essential, 030217 neurology & neurosurgery, Atovaquone, medicine.drug
Abstract: International audience; Understanding the mode of action of antimalarials is central to optimizing their use and the discovery of new therapeutics. Currently used antimalarials belong to a limited series of chemical structures and their mechanisms of action are coutinuously debated. Whereas the involvement of reactive species that in turn kill the parasites sensitive to oxidative stress, is accepted for artemisinins, little is known about the generation of such species in the case of quinolines or hydroxynaphtoquinone. Moreover, the nature of the reactive species involved has never been characterized in Plasmodium-infected erythrocytes. The aim of this work was to determine and elucidate the production of the primary radical, superoxide in Plasmodium-infected erythrocytes treated with artemisinin, dihydroartemisinin, chloroquine and atovaquone, as representatives of three major classes of antimalarials. The intracellular generation of superoxide was quantified by liquid chromatography coupled to mass spectrometry (LC-MS). We demonstrated that artemisinins, atovaquone and to a lesser extent chloroquine, generate significant levels of superoxide radicals in Plasmodium falciparum sensitive strains. More so, the production of superoxide was lowered in chloroquine-resistant strain of Plasmodium treated with chloroquine. These results consolidate the knowledge about the mechanism of action of these different antimalarials and should be taken into consideration in the design of future drugs to fight drug-resistant parasites.
Published: 2021

6. Effect of ion doping in silica-based nanoparticles on the hemolytic and oxidative activity in contact with human erythrocytes

Author: Christos B. Lioutas, Konstantina Kazeli, Georgia K. Pouroutzidou, Ioannis Tsamesidis, Eleana Kontonasaki, Evgenia Lymperaki, Antonella Pantaleo, Karine Reybier, Pierre Perio, and Evi Christodoulou
Subjects: 0301 basic medicine, Antioxidant, Erythrocytes, medicine.medical_treatment, chemistry.chemical_element, Nanoparticle, Calcium, Toxicology, medicine.disease_cause, Lipid peroxidation, 03 medical and health sciences, chemistry.chemical_compound, 0302 clinical medicine, Microscopy, Electron, Transmission, Malondialdehyde, Spectroscopy, Fourier Transform Infrared, medicine, Humans, Magnesium, Cells, Cultured, General Medicine, Hydrogen Peroxide, Silicon Dioxide, Copper, Glutathione, 030104 developmental biology, chemistry, 030220 oncology & carcinogenesis, Calcium silicate, Nanoparticles, Oxidative stress, Nuclear chemistry
Abstract: Aim The aim of this study was the synthesis of ion doped silica-based nanoparticles and the evaluation of their toxic effect on erythrocytes. Materials & methods Their synthesis was performed using the sol-gel method, by the progressive addition of calcium, magnesium and copper ions on pure silica nanoparticles. The toxicity evaluation was based on hemolysis, lipid peroxidation, ROS, H2O2 species and antioxidant enzyme production. Results The addition of Mg and Cu in the SNs presented better hemocompatibility by protecting erythrocytes from oxidative stress. Conclusion Ion doping with magnesium in the investigated calcium silicate system induces a protective effect in erythrocyte membrane in compare with pure silica nanoparticles.
Published: 2019

7. Electrochemical and Spin-Trapping Properties of para-substituted α-Phenyl-N-tert-butyl Nitrones

Author: Frederick A. Villamena, Pierre Perio, Paul-Louis Fabre, Grégory Durand, Béatrice Tuccio, Marie Rosselin, Institut des Biomolécules Max Mousseron [Pôle Chimie Balard] (IBMM), Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), Avignon Université (AU), Institut de Chimie Radicalaire (ICR), Aix Marseille Université (AMU)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Pharmacochimie et Biologie pour le Développement (PHARMA-DEV), Institut de Recherche pour le Développement (IRD)-Institut de Chimie de Toulouse (ICT), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT), Ohio State University [Columbus] (OSU), NIH National Heart, Lung, Blood Institute grant RO1HL81248, Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie de Toulouse (ICT-FR 2599), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Institut de Recherche pour le Développement (IRD)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), and Université Fédérale Toulouse Midi-Pyrénées-Institut de Recherche pour le Développement (IRD)
Subjects: chemistry.chemical_classification, Spin-Trapping, Free Radicals, Spin trapping, 010405 organic chemistry, [SDV]Life Sciences [q-bio], General Chemical Engineering, Kinetics, Nitrones, 010402 general chemistry, Photochemistry, 01 natural sciences, Redox, Antioxidants, 0104 chemical sciences, Nitrone, Oxidative Stress, chemistry.chemical_compound, chemistry, Nucleophile, Electrochemistry, Polar effect, Hydroxymethyl, Cyclic voltammetry
Abstract: International audience; Nitrones are known both as therapeutic antioxidants and efficient spin-traps. In this work, the redox behavior of various para-substituted α-phenyl-N-tert-butyl nitrones (PBN) was studied by cyclic voltammetry. The polar effect of the substituents was found to correlate with the electrochemical properties of the nitronyl function. Compounds bearing an electron-withdrawing group were more easily reduced than those having an electron-donating group and an opposite trend was observed for the oxidation. Ease of oxidation was also computationally rationalized using DFT approach showing increased ease of oxidation with electron donating functionalities. Since electrochemical properties of nitrones are known to correlate with biological properties, this work provides insights in the design of potent nitrone antioxidants. Using cyclic voltammetry the relative rate of superoxide trapping by nitrones was investigated and compared to the classical antioxidant BHT. The determination of the relative rate of phenyl radical trapping was also carried out but showed no clear correlation with the nature of the substituents. This indicates the absence of a polar effect in agreement with previous data and further supports the intermediate nature, that is, non- or weakly nucleophile, of phenyl radical. On the contrary kinetics of hydroxymethyl radical trapping was found to correlate with the nature of the substituents, demonstrating the nucleophilic nature of its addition onto nitrones.
Published: 2016

8. Synthesis and Evaluation of Antiplasmodial Activities of Fluorinated 6-Amino- 2-Aryl-3H-Indolone-N-Oxides

Author: Amani Mejai, Mohamed Haddad, Karine Reybier, Rym Abidi, Gneigny Tchani, Sandra Bourgeade Delmas, Pierre Perio, Ennaji Najahi, Françoise Nepveu, Laure Vendier, Université de Carthage - University of Carthage, Pharmacochimie et Biologie pour le Développement (PHARMA-DEV), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie de Toulouse (ICT-FR 2599), Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut de Chimie du CNRS (INC)-Institut de Recherche pour le Développement (IRD), Université de Lomé [Togo], Laboratoire de chimie de coordination (LCC), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie de Toulouse (ICT-FR 2599), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Institut de Recherche pour le Développement (IRD)-Institut de Chimie de Toulouse (ICT), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT), Institut de Chimie de Toulouse (ICT), and Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Stereochemistry, [SDV]Life Sciences [q-bio], 01 natural sciences, 03 medical and health sciences, chemistry.chemical_compound, Synthesis, [SDV.SP.MED]Life Sciences [q-bio]/Pharmaceutical sciences/Medication, In vivo, Cytotoxicity, IC50, 030304 developmental biology, 0303 health sciences, biology, Cytotoxic activity, Chemistry, Aryl, Plasmodium falciparum, Fluorinated indolone-N-oxides, [SDV.SP]Life Sciences [q-bio]/Pharmaceutical sciences, biology.organism_classification, In vitro, 0104 chemical sciences, 010404 medicinal & biomolecular chemistry, Vero cell, Antiplasmodial activity, Selectivity
Abstract: International audience; A series of novel 6-amino-2-aryl-3H-indolone-N-oxides were synthesized at yields of up to 65% and characterized; onewas further characterized using X-ray crystallographic analysis.Synthesized compounds were evaluated for their in vitro activity against a chloroquine-resistant (FcB1) strain of Plasmodium falciparum, as well as for the 50% cytotoxic concentration (CC50) on Vero cell lines. The most promising activities were observed for the fluorinated compounds, the most active in vitro being 6-(2-morpholinoacetamido)-2-(4-(trifluoromethoxy)phenyl)-3H-indolone-N-oxide (IC50: 15.5 nM). In addition, these compounds showed weak cytotoxicity leading to selectivity index values of >170, thus warranting further in vitro and in vivo studies.
Published: 2018

9. LUCS (Light-Up Cell System), a universal high throughput assay for homeostasis evaluation in live cells

Author: Sylvain Derick, Camille Gironde, Pierre Perio, Karine Reybier, Françoise Nepveu, Alain Jauneau, and Christophe Furger
Subjects: Singlet Oxygen, Hydroxyl Radical, lcsh:R, Electron Spin Resonance Spectroscopy, lcsh:Medicine, Homeostasis, lcsh:Q, lcsh:Science, Article, Fluorescent Dyes
Abstract: Observations of fluorescent cyanine dye behavior under illumination at 500 nm lead to a novel concept in cell biology allowing the development of a new live cell assay called LUCS, for Light-Up Cell System, measuring homeostasis in live cells. Optimization of the LUCS process resulted in a standardized, straightforward and high throughput assay with applications in toxicity assessment. The mechanisms of the LUCS process were investigated. Electron Paramagnetic Resonance experiments showed that the singlet oxygen and hydroxyl radical are involved downstream of the light effect, presumably leading to deleterious oxidative stress that massively opens access of the dye to its intracellular target. Reversible modulation of LUCS by both verapamil and proton availability indicated that plasma membrane proton/cation antiporters, possibly of the MATE drug efflux transport family, are involved. A mechanistic model is presented. Our data show that intracellular oxidation can be controlled by tuning light energy, opening applications in regulatory purposes, anti-oxidant research, chemotherapy efficacy and dynamic phototherapy strategies.
Published: 2017

10. Oxidative stress and neurodegeneration: The possible contribution of quinone reductase 2

Author: Françoise Nepveu, Karine Reybier, Jan Sudor, Laure-Estelle Cassagnes, Monivan Chhour, Régis Gayon, Pierre Perio, Jean A. Boutin, Gilles Ferry, Pharmacochimie et Biologie pour le Développement (PHARMA-DEV), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie de Toulouse (ICT-FR 2599), Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut de Chimie du CNRS (INC)-Institut de Recherche pour le Développement (IRD), Vectalys SAS, Institut de Recherches SERVIER (IRS), Institut de Recherche pour le Développement (IRD)-Institut de Chimie de Toulouse (ICT), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), and Université de Toulouse (UT)
Subjects: 0301 basic medicine, Programmed cell death, Radical, [SDV]Life Sciences [q-bio], Catechol quinone, medicine.disease_cause, Quinone oxidoreductase, Neurodegenerative disease, Biochemistry, 03 medical and health sciences, chemistry.chemical_compound, Adrenochrome, Mice, 0302 clinical medicine, Physiology (medical), medicine, NAD(P)H Dehydrogenase (Quinone), Animals, Humans, Indolequinones, chemistry.chemical_classification, Mice, Knockout, Neurons, Reactive oxygen species, Chemistry, Chinese hamster ovary cell, Neurodegeneration, ROS, medicine.disease, QR2, 3. Good health, Cell biology, Oxidative Stress, 030104 developmental biology, Oxidative stress, Redox cycle, Nerve Degeneration, Dopachrome, K562 Cells, Reactive Oxygen Species, 030217 neurology & neurosurgery
Abstract: International audience; There is increasing evidence that oxidative stress is involved in the etiology and pathogenesis of neurodegenerative disorders. Overproduction of reactive oxygen species (ROS) is due in part to the reactivity of catecholamines, such as dopamine, adrenaline, and noradrenaline. These molecules are rapidly converted, chemically or enzymatically, into catechol-quinone and then into highly deleterious semiquinone radicals after 1-electron reduction in cells. Notably, the overexpression of dihydronicotinamide riboside:quinone oxidoreductase (QR2) in Chinese hamster ovary (CHO) cells increases the production of ROS, mainly superoxide radicals, when it is exposed to exogenous catechol-quinones (e.g. dopachrome, aminochrome, and adrenochrome). Here we used electron paramagnetic resonance analysis to demonstrate that the phenomenon observed in CHO cells is also seen in human leukemic cells (K562 cells) that naturally express QR2. Moreover, by manipulating the level of QR2 in neuronal cells, including immortalized neuroblast cells and ex vivo neurons isolated from QR2 knockout animals, we showed that there is a direct relationship between QR2-mediated quinone reduction and ROS overproduction. Supporting this result, the withdraw of the QR2 co-factor (BNAH) or the addition of the specific QR2 inhibitor S29434 suppressed oxidative stress. Taken together, these data suggest that the overexpression of QR2 in brain cells in the presence of catechol quinones might lead to ROS-induced cell death via the rapid conversion of superoxide radicals into hydrogen peroxide and then into highly reactive hydroxyl radicals. Thus, QR2 may be implicated in the early stages of neurodegenerative disorders.
Published: 2017

11. Dereplication of natural products from complex extracts by regression analysis and molecular networking: case study of redox-active compounds from Viola alba subsp. dehnhardtii

Author: Chiobouaphong Pharkeovilay, Nicolas Fabre, Thierry Talou, Françoise Nepveu, Valérie Bonzon-Ponnet, Karine Reybier, Nathalie Martins-Froment, Guillaume Marti, Justine Chervin, Pierre Perio, Centre National de la Recherche Scientifique - CNRS (FRANCE), Groupe Berdoues (FRANCE), Institut National Polytechnique de Toulouse - INPT (FRANCE), Institut National de la Recherche Agronomique - INRA (FRANCE), Institut de Recherche pour le Développement - IRD (FRANCE), Université Toulouse III - Paul Sabatier - UT3 (FRANCE), Chimie Agro-Industrielle (CAI), Institut National de la Recherche Agronomique (INRA)-Ecole nationale supérieure des ingénieurs en arts chimiques et technologiques-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées, Pharmacochimie et Biologie pour le Développement (PHARMA-DEV), Institut de Recherche pour le Développement (IRD)-Institut de Chimie de Toulouse (ICT-FR 2599), Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS), Institut de Recherche pour le Développement (IRD [France-Ouest]), Université Fédérale Toulouse Midi-Pyrénées, Parfumerie Berdoues, Institut de Chimie de Toulouse, Service commun de spectrométrie de masse, Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Ecole nationale supérieure des ingénieurs en arts chimiques et technologiques-Institut National de la Recherche Agronomique (INRA), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie de Toulouse (ICT-FR 2599), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut de Chimie du CNRS (INC)-Institut de Recherche pour le Développement (IRD), Groupe Berdoues Parfums et Cosmétiques, Institut de Chimie de Toulouse (ICT-FR 2599), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC), Institut National de la Recherche Agronomique (INRA)-Ecole nationale supérieure des ingénieurs en arts chimiques et technologiques (ENSIACET), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Université de Toulouse (UT), Institut de Recherche pour le Développement (IRD)-Institut de Chimie de Toulouse (ICT), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT), Institut de Chimie de Toulouse (ICT), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), and Institut National Polytechnique de Toulouse - Toulouse INP (FRANCE)
Subjects: natural product, natural products, DPPH, produit naturel, Endocrinology, Diabetes and Metabolism, Biochimie, Biologie Moléculaire, Dereplication Metabolomics Molecular networking Natural products Redox active properties UHPLC–HRMS, Clinical Biochemistry, Redox active properties, Fractionation, Biology, 01 natural sciences, Biochemistry, Redox, chemistry.chemical_compound, Metabolomics, UHPLC-HRMS, [SDV.BBM]Life Sciences [q-bio]/Biochemistry, Molecular Biology, Molecular networking, Natural products, molecular networking, Natural product, 010405 organic chemistry, 010401 analytical chemistry, chimie agroindustrielle, Dereplication, dereplication, metabolomics, Combinatorial chemistry, Thin-layer chromatography, 0104 chemical sciences, redox active properties, chemistry, Polyphenol, viola, Natural Product Research, métabolomique, UHPLC–HRMS
Abstract: Introduction In natural product research, bioassay-guided fractionation was previously widely employed but is now judged to be inadequate in terms of time and cost, particularly if only known compounds are ultimately isolated. The development of metabolomics, along with improvements in analytical tools, allows comprehensive metabolite profiling. This enables dereplication to target unknown active compounds early in the purification workflow. Objectives Starting from an ethanolic extract of violet leaves, this study aims to predict redox active compounds within a complex matrix through an untargeted metabolomics approach and correlation analysis. Methods Rapid fractionation of crude extracts was carried out followed by multivariate data analysis (MVA) of liquid chromatography-high resolution mass spectrometry (LC-HRMS) profiles. In parallel, redox active properties were evaluated by the capacity of the molecules to reduce 2,2-diphenyl-1-picrylhydrazyl (DPPH.) and superoxide (O-2(.-)) radicals using UV-Vis and electron spin resonance spectroscopies (ESR), respectively. A spectral similarity network (molecular networking) was used to highlight clusters involved in the observed redox activities. Results Dereplication on Viola alba subsp. dehnhardtii highlighted a reproducible pool of redox active molecules. Polyphenols, particularly O-glycosylated coumarins and C-glycosylated flavonoids, were identified and de novo dereplicated through molecular networking. Confirmatory analyses were undertaken by thin layer chromatography (TLC)-DPPH-MS assays and nuclear magnetic resonance (NMR) spectra of the most active compounds. Conclusion Our dereplication strategy allowed the screening of leaf extracts to highlight new biologically active metabolites in few steps with a limited amount of crude material and reduced time-consuming manipulations. (LC-HRMS) profiles. In parallel, redox active properties were evaluated by the capacity of the molecules to reduce 2,2-diphenyl-1-picrylhydrazyl (DPPH.) and superoxide (O-2(.-)) radicals using UV-Vis and electron spin resonance spectroscopies (ESR), respectively. A spectral similarity network (molecular networking) was used to highlight clusters involved in the observed redox activities. Results Dereplication on Viola alba subsp. dehnhardtii highlighted a reproducible pool of redox active molecules. Polyphenols, particularly O-glycosylated coumarins and C-glycosylated flavonoids, were identified and de novo dereplicated through molecular networking. Confirmatory analyses were undertaken by thin layer chromatography (TLC)-DPPH-MS assays and nuclear magnetic resonance (NMR) spectra of the most active compounds. Conclusion Our dereplication strategy allowed the screening of leaf extracts to highlight new biologically active metabolites in few steps with a limited amount of crude material and reduced time-consuming manipulations. This approach could be applied to any kind of natural extract for the study of various biological activities.
Published: 2017

12. Role of quinone reductase 2 in the antimalarial properties of indolone-type derivatives

Author: Karine Reybier, Ennaji Najahi, Nambinina V. Rakotoarivelo, Françoise Nepveu, Alexis Valentin, Pierre Perio, Jean A. Boutin, Serena Sirigu, Andrew Thompson, Gilles Ferry, Régis Gayon, Laure-Estelle Cassagnes, Leonard M. G. Chavas, Pharmacochimie et Biologie pour le Développement (PHARMA-DEV), Institut de Recherche pour le Développement (IRD)-Institut de Chimie de Toulouse (ICT-FR 2599), Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC), Synchrotron SOLEIL (SSOLEIL), Centre National de la Recherche Scientifique (CNRS), Vectalys SAS, Institut de Recherches Servier, Centre de Recherches de Croissy, Institut de Recherche pour le Développement (IRD)-Institut de Chimie de Toulouse (ICT), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), and Université de Toulouse (UT)
Subjects: 0301 basic medicine, Models, Molecular, Indoles, Protein Conformation, malaria, inhibitor, mechanism, human quinone reductase 2, indolones, Pharmaceutical Science, Reductase, Analytical Chemistry, 0302 clinical medicine, Drug Discovery, chemistry.chemical_classification, biology, Molecular Structure, Chemistry, 3. Good health, Quinone, Chemistry (miscellaneous), 030220 oncology & carcinogenesis, Molecular Medicine, medicine.symptom, Protein Binding, Free Radicals, Stereochemistry, Radical, Plasmodium falciparum, Flavin group, CHO Cells, Redox, Article, lcsh:QD241-441, 03 medical and health sciences, Antimalarials, Cricetulus, lcsh:Organic chemistry, medicine, Animals, Humans, [SDV.MP.PAR]Life Sciences [q-bio]/Microbiology and Parasitology/Parasitology, Physical and Theoretical Chemistry, Quinone Reductases, Organic Chemistry, biology.organism_classification, 030104 developmental biology, Enzyme, Mechanism of action, [SDV.SP.PHARMA]Life Sciences [q-bio]/Pharmaceutical sciences/Pharmacology, Reactive Oxygen Species
Abstract: International audience; Indolone-N-oxides have antiplasmodial properties against Plasmodium falciparum at the erythrocytic stage, with IC50 values in the nanomolar range. The mechanism of action of indolone derivatives involves the production of free radicals, which follows their bioreduction by an unknown mechanism. In this study, we hypothesized that human quinone reductase 2 (hQR2), known to act as a flavin redox switch upon binding to the broadly used antimalarial chloroquine, could be involved in the activity of the redox-active indolone derivatives. Therefore, we investigated the role of hQR2 in the reduction of indolone derivatives. We analyzed the interaction between hQR2 and several indolone-type derivatives by examining enzymatic kinetics, the substrate/protein complex structure with X-ray diffraction analysis, and the production of free radicals with electron paramagnetic resonance. The reduction of each compound in cells overexpressing hQR2 was compared to its reduction in naïve cells. This process could be inhibited by the specific hQR2 inhibitor, S29434. These results confirmed that the anti-malarial activity of indolone-type derivatives was linked to their ability to serve as hQR2 substrates and not as hQR2 inhibitors as reported for chloroquine, leading to the possibility that substrate of hQR2 could be considered as a new avenue for the design of new antimalarial compounds.
Published: 2017

13. ISOINDOLINOTRIAZOLE DERIVATIVES: SYNTHESIS BY THE AZIDE-ALKYNE CYCLOADDITION CLICK CHEMISTRY

Author: Françoise Nepveu, Ennaji Najahi, Etienne Hollande, Nambinina V. Rakotoarivelo, and Pierre Perio
Subjects: chemistry.chemical_classification, chemistry.chemical_compound, chemistry, Triazole, Proton NMR, Click chemistry, Alkyne, Moiety, Organic chemistry, Azide, Carbon-13 NMR, Combinatorial chemistry, Cycloaddition
Abstract: A novel series of isoindolinotriazole derivatives with different substituents in the triazole moiety were synthesized via copper-catalyzed cycloaddition (CuAAC) click chemistry between 2-(meta- or para-ethynylphenyl)-4,6-dimethoxyisoindolin-1-ones and several azides. The synthesized triazoles were characterized by IR, 1H NMR, 13C NMR and mass spectral techniques.
Published: 2014

14. EPR Spectroelectrochemical Investigation of Guanine Radical Formation and Environment Effects

Author: Clotilde Ribaut, Guillaume Bordeau, Paul-Louis Fabre, Karine Reybier, Olivier Reynes, Valérie Sartor, Pierre Perio, Nadia Chouini-Lalanne, Interactions moléculaires et réactivité chimique et photochimique (IMRCP), Institut de Chimie de Toulouse (ICT), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Institut Ecologie et Environnement (INEE), Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Fédération de Recherche Fluides, Energie, Réacteurs, Matériaux et Transferts (FERMAT), Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Pharmacochimie et Biologie pour le Développement (PHARMA-DEV), Institut de Recherche pour le Développement (IRD)-Institut de Chimie de Toulouse (ICT), Université de Toulouse (UT), Laboratoire de Génie Chimique (LGC), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Institut de Chimie de Toulouse (ICT-FR 2599), Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD), Institut de Recherche pour le Développement (IRD)-Institut de Chimie de Toulouse (ICT-FR 2599), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC), Laboratoire de génie chimique [ancien site de Basso-Cambo] (LGC), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées, Centre National de la Recherche Scientifique - CNRS (FRANCE), Institut National Polytechnique de Toulouse - INPT (FRANCE), Institut de Recherche pour le Développement - IRD (FRANCE), Université Toulouse III - Paul Sabatier - UT3 (FRANCE), and Institut National Polytechnique de Toulouse - Toulouse INP (FRANCE)
Subjects: inorganic chemicals, Guanine, Free Radicals, chemistry.chemical_element, Electrochemistry, Photochemistry, Ruthenium, law.invention, Cyclic N-Oxides, chemistry.chemical_compound, [CHIM.GENI]Chemical Sciences/Chemical engineering, Deprotonation, Coordination Complexes, law, Oxidation, Genetics, Materials Chemistry, Génie chimique, [SPI.GPROC]Engineering Sciences [physics]/Chemical and Process Engineering, Nucleotide, Physical and Theoretical Chemistry, Génie des procédés, Electron paramagnetic resonance, chemistry.chemical_classification, Spin trapping, Electron Spin Resonance Spectroscopy, Guanine radica, Surfaces, Coatings and Films, Nucleic acids, chemistry, Radical ion, Oxidation-Reduction, Spin Trapping, Electron paramagnetic resonance spectroscopy
Abstract: International audience; Guanine radical detection was carried out by a new convenient and efficient method coupling electron paramagnetic resonance spectroscopy and indirect electrooxidation of guanine in different biological environments, from the free nucleotide to several types of DNA substrates. Compared to the widely used photoirradiation method, this method appeared more selective in the choice of the electrochemical mediator. Carried out in presence of a ruthenium mediator and PBN as spin trap, this method revealed two types of EPR spectra depending of the environment of the guanine radical. Both EPR spectra show the trapping of the neutral guanine radical G(−H)• obtained after fast deprotonation of the radical cation G•+. However, they differ by the atom where the trapped radical is centered. This difference highlights the structural dependency of the environment on the nature of the radical formed. This work gave the evidence of an innovative method to detect in situ the guanine radical.
Published: 2014

15. Behavior ofN-oxide derivatives in atmospheric pressure ionization mass spectrometry

Author: Françoise Nepveu, François Couderc, Hany Ibrahim, Fabrice Collin, and Pierre Perio
Subjects: 0303 health sciences, Atmospheric pressure, Chemistry, Electrospray ionization, 010401 analytical chemistry, Organic Chemistry, Analytical chemistry, Atmospheric-pressure chemical ionization, Mass spectrometry, 01 natural sciences, Dissociation (chemistry), 0104 chemical sciences, Analytical Chemistry, 03 medical and health sciences, Fragmentation (mass spectrometry), Ionization, Deoxygenation, Spectroscopy, 030304 developmental biology
Abstract: RATIONALE Indolone-N-oxide derivatives possess interesting biological properties. The analysis of these compounds using mass spectrometry (MS) may lead to interference or under-estimation due to the tendency of the N-oxides to lose oxygen. All the previous works focused only on the temperature of the heated parts (vaporizer and ion-transfer tube) of the mass spectrometer without investigating other parameters. This work is extended to the investigation of other parameters. METHODS The behavior of N-oxides during atmospheric pressure chemical ionization (APCI) and electrospray ionization (ESI) has been investigated using MSn ion trap mass spectrometry. Different parameters were investigated to clarify the factors implicated in the deoxygenation process. The investigated parameters were vaporizer temperature (APCI), ion-transfer tube temperature, solvent type, and the flow rates of the sheath gas, auxiliary gas, sweep gas and mobile phase. RESULTS The deoxygenation increased when the vaporizer temperature increased. The extent of the 'thermally' induced deoxygenation was inversely proportional to the ion-transfer tube temperature and auxiliary gas flow rate and in direct proportion to the mobile phase flow rate. Deoxygenation was not detected under MS/MS fragmentation and hence it is a non-collision-induced dissociation. N-Oxides have the tendency to form abundant 'non-classical' dimers under ESI, which fragment via dehydration rather than giving their corresponding monomer. CONCLUSIONS Deoxygenation is not solely a 'classical' thermal process but it is a thermal process that is solvent-mediated in the source. Deoxygenation was maximal with an APCI source while dimerization was predominant with an ESI source. Therefore, attention should be paid to these molecular changes in the mass spectrometer as well as to the choice of the ionization mode for N-oxides. Copyright © 2013 John Wiley & Sons, Ltd.
Published: 2013

16. Electrochemical behavior of indolone-N-oxides: Relationship to structure and antiplasmodial activity

Author: Pierre Perio, Karine Reybier, Paul-Louis Fabre, Hany Ibrahim, Françoise Nepveu, Armelle Montrose, Thi Hoang Yen Nguyen, Pharmacochimie et Biologie pour le Développement (PHARMA-DEV), Institut de Recherche pour le Développement (IRD)-Institut de Chimie de Toulouse (ICT-FR 2599), Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC), Laboratoire de génie chimique [ancien site de Basso-Cambo] (LGC), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées, Centre National de la Recherche Scientifique - CNRS (FRANCE), Institut National Polytechnique de Toulouse - Toulouse INP (FRANCE), Institut de Recherche pour le Développement - IRD (FRANCE), Université Toulouse III - Paul Sabatier - UT3 (FRANCE), Institut de Recherche pour le Développement (IRD)-Institut de Chimie de Toulouse (ICT), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT), Laboratoire de Génie Chimique (LGC), Université de Toulouse (UT)-Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), and Institut National Polytechnique de Toulouse - INPT (FRANCE)
Subjects: Indolone-N-oxides, Nitroxide mediated radical polymerization, Indoles, Cyclic voltammetry, Stereochemistry, Plasmodium falciparum, Antiprotozoal Agents, Biophysics, Protonation, 010402 general chemistry, 01 natural sciences, Redox, Nitrone, law.invention, Structure-Activity Relationship, Antimalarials, 03 medical and health sciences, chemistry.chemical_compound, Electron transfer, [CHIM.GENI]Chemical Sciences/Chemical engineering, law, Electrochemistry, Radical, Génie chimique, Phenyl group, Physical and Theoretical Chemistry, Electron paramagnetic resonance, 030304 developmental biology, chemistry.chemical_classification, 0303 health sciences, Radical nitroxide anion, Electron Spin Resonance Spectroscopy, Oxides, General Medicine, 0104 chemical sciences, 3. Good health, chemistry, nitroxide anion, EPR, Hydrophobic and Hydrophilic Interactions, Oxidation-Reduction
Abstract: International audience; Indolone-N-oxides exert high parasiticidal activity at the nanomolar level in vitro against Plasmodiumfalciparum, the parasite responsible for malaria. The bioreductive character of these molecules was investigated using cyclic voltammetry and EPR spectroelectrochemistry to examine the relationship between electrochemical behavior and antimalarial activity and to understand theirmechanisms of action. For all the compounds (37 compounds) studied, the voltammograms recorded in acetonitrile showed a well-defined and reversible redox couple followed by a second complicated electron transfer. The first reduction (−0.88 VbE1/2b−0.50 V vs. SCE) was attributed to the reduction of the N-oxide function to form a radical nitroxide anion. The second reduction (−1.65 VbE1/2b−1.14 V vs. SCE) was assigned to the reduction of the ketone function. By coupling electrochemistry with EPR spectroscopy, the EPR spectra confirmed the formation of the nitroxide anion radical.Moreover, the experiments demonstrated that a slowprotonation occurs at the carbon of the nitrone function and not at the NO function. A relationship between electrochemical behavior and indolone-N-oxide structure can be established for compounds with R1=―OCH3, R2=H, and electron-withdrawing substituents on the phenyl group at R3. The results help in the design of new molecules with more potent in vivo antimalarial activity.
Published: 2012

17. LC-MS based metabolomic approach applied to bioactive molecules identification: case study of a comprehesive chemodiversity screening of Viola genus

Author: Guillaume Marti, Nicolas Fabre, Karine Reybier, G Vilarem, Pierre Perio, Thierry Talou, N Martins, J Chervin, Françoise Nepveu, Pharmacochimie et Biologie pour le Développement (PHARMA-DEV), Institut de Recherche pour le Développement (IRD)-Institut de Chimie de Toulouse (ICT-FR 2599), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées, Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC), Groupe Berdoues Parfums et Cosmétiques, Chimie Agro-Industrielle (CAI), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Ecole nationale supérieure des ingénieurs en arts chimiques et technologiques-Institut National de la Recherche Agronomique (INRA), Regional Council Midi-Pyrenees (Project CLE 13053062), Institut National de la Recherche Agronomique (INRA)-Ecole nationale supérieure des ingénieurs en arts chimiques et technologiques-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées, Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS), Institut de Recherche pour le Développement (IRD [France-Ouest]), Parfumerie Berdoues, Institut de Recherche pour le Développement (IRD)-Institut de Chimie de Toulouse (ICT), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT), Institut National de la Recherche Agronomique (INRA)-Ecole nationale supérieure des ingénieurs en arts chimiques et technologiques (ENSIACET), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut National Polytechnique (Toulouse) (Toulouse INP), and Université de Toulouse (UT)-Université de Toulouse (UT)
Subjects: DPPH, Viola alba, [SDV]Life Sciences [q-bio], violets, Pharmaceutical Science, antioxidant activity, activité anti-oxydante, 01 natural sciences, Analytical Chemistry, LC-MS profiles, analyse métabolomique, chemistry.chemical_compound, Metabolomics, Liquid chromatography–mass spectrometry, métabolite, Drug Discovery, chimiotaxonomie, viola odorata, composé polyphénolique, ComputingMilieux_MISCELLANEOUS, Viola (butterfly), Pharmacology, biology, Traditional medicine, 010405 organic chemistry, Organic Chemistry, biology.organism_classification, metabolomics, 0104 chemical sciences, 010404 medicinal & biomolecular chemistry, chemotaxonomy, Complementary and alternative medicine, chemistry, Chemotaxonomy, Polyphenol, viola, Molecular Medicine, Identification (biology), [SDV.AEN]Life Sciences [q-bio]/Food and Nutrition, industrie cosmetique
Abstract: 9th Joint Natural Products Conference 2016. July 24-27th. Copenhagen (Denmark); The objective of this study, part of the Viola tolosa project, was to evaluate the chemical potential of Viola genus samples without impacting the bioresource1. Therefore, a metabolomics approach was used to obtain a comprehensive screening of the collection of violets from the French Violet Conservatory hosted by the Toulouse Municipal Greenhouses. Focussed on the non-volatile compounds of leaves, this approach involved multivariate analysis of LC-MSE high resolution profiles of total extracts along a parallel screening of their antioxidant activities. Then, the dereplication of putative active compounds was obtained by correlation analysis presenting two main benefits: a limited amount of crude material and restricted time consuming manipulations. The relevance of this approach was established by TLC-DPPH assays of extracts and subsequent identification of DPPH active spots using a TLC-MS interface. The first results on Viola alba subsp. dehnhardtii aka Violet of Toulouse, highlighted the presence of antioxidant polyphenols never characterized in this genus. The results obtained will permit the assessment of the chemodiversity of the violet collection based on metabolite analysis and future identifications of potentially biologically active extracts or molecules for further dermocosmetic valorizations. Combined with future analysis of native volatile compounds emitted by fresh flowers by SPME-GC-O-MS, this holistic approach should provide a comprehensive chemotaxonomy of violets.
Published: 2016

18. Evolution, radiation and chemotaxonomy of Lamellodysidea, a demosponge genus with anti-plasmodial metabolites

Author: Cécile Debitus, Mayuri Chandra, Bernard Banaigs, Pierre Perio, Carsten W. Wolff, John N. A. Hooper, Sylvain Petek, Dirk Erpenbeck, Gert Wörheide, Patricia Sutcliffe, and Isabelle Bonnard
Subjects: Ecology, biology, Phylogenetic tree, Zoology, Aquatic Science, biology.organism_classification, Taxon, Demosponge, Phylogenetics, Chemotaxonomy, Botany, Molecular phylogenetics, Taxonomy (biology), Dictyoceratida, Ecology, Evolution, Behavior and Systematics
Abstract: Sponges of the family Dysideidae (Dictyoceratida) are renowned for their diversity of secondary metabolites, and its genus Lamellodysidea, particularly Lamellodysidea herbacea, is the most studied taxon biochemically. Despite its importance, the taxonomic status of L. herbacea—whether it is a distinct species or a species complex—has never been assessed. Recent biochemical profiling revealed anti-plasmodial activity of brominated compounds in Lamellodysidea of the Pacific. Here, we present a comparative chemotaxonomic and molecular analysis of selected Dysideidae from the Pacific and the Indian Ocean (New Caledonia, Great Barrier Reef, Fiji, Mayotte, Guam, Palau). We investigated the phylogenetic relationships between the populations and assessed their bioactive (PBDE) compounds in order to unravel the taxonomic status of this commercially important group of sponges and assessed patterns of dispersal and biochemical variation. The molecular phylogeny was based on the internal transcribed ribosomal spacer and compared against a PBDE phylogeny for several specimens. Molecular data revealed a diversity of Indo-Pacific L.herbacea populations, also reflected by different PBDE compound profiles. Molecular and biochemical data also revealed a Lamellodysidea species new to science. Several specimens misidentified as Lamellodysidea were detected based on their position on different clades in the molecular phylogeny and their production of different halogenated compounds (brominated vs. chlorinated). The direct comparison of molecular and biochemical data also provided evidence for the occurrence of a host switch event and support for the theory that abiotic factors, such as sedimentation, affect the chemical constituents produced in L. herbacea.
Published: 2012

19. In cellulo monitoring of quinone reductase activity and reactive oxygen species production during the redox cycling of 1,2 and 1,4 quinones

Author: Françoise Nepveu, Régis Gayon, Mathias Antoine, Natacha Moulharat, Karine Reybier, Laure-Estelle Cassagnes, Gilles Ferry, Pierre Perio, Jean A. Boutin, Pharmacochimie et Biologie pour le Développement (PHARMA-DEV), Institut de Recherche pour le Développement (IRD)-Institut de Chimie de Toulouse (ICT-FR 2599), Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC), Pharmacologie Moléculaire et Cellulaire, Institut de Recherche Servier, Vectalys SAS, Institut de Recherche pour le Développement (IRD)-Institut de Chimie de Toulouse (ICT), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), and Université de Toulouse (UT)
Subjects: Ortho-quinones, Radical, Free radicals, CHO Cells, Reductase, medicine.disease_cause, Biochemistry, chemistry.chemical_compound, Quinone Reductases, Cricetulus, [CHIM.ANAL]Chemical Sciences/Analytical chemistry, Physiology (medical), Cricetinae, medicine, Benzoquinones, Animals, Para-quinones, [SDV.BBM.BC]Life Sciences [q-bio]/Biochemistry, Molecular Biology/Biochemistry [q-bio.BM], chemistry.chemical_classification, Reactive oxygen species, Electron Spin Resonance Spectroscopy, Cytochrome P450 reductase, Quinone, Oxygen, chemistry, Quinone reductase, Oxidative stress, Dopachrome, NQO1, NQO2, EPR, Oxidation-Reduction
Abstract: International audience; Quinones are highly reactive molecules that readily undergo either one- or two-electron reduction. One-electron reduction of quinones or their derivatives by enzymes such as cytochrome P450 reductase or other flavoproteins generates unstable semiquinones, which undergo redox cycling in the presence of molecular oxygen leading to the formation of highly reactive oxygen species. Quinone reductases 1 and 2 (QR1 and QR2) catalyze the two-electron reduction of quinones to form hydroquinones, which can be removed from the cell by conjugation of the hydroxyl with glucuronide or sulfate thus avoiding its autoxidation and the formation of free radicals and highly reactive oxygen species. This characteristic confers a detoxifying enzyme role to QR1 and QR2, even if this character is strongly linked to the excretion capacity of the cell. Using EPR spectroscopy and confocal microscopy we demonstrated that the amount of reactive oxygen species (ROS) produced by Chinese hamster ovary (CHO) cells overexpressing QR1 or QR2 compared to naive CHO cells was determined by the quinone structural type. Indeed, whereas the amount of ROS produced in the cell was strongly decreased with para-quinones such as menadione in the presence of quinone reductase 1 or 2, a strong increase in ROS was recorded with ortho-quinones such as adrenochrome, aminochrome, dopachrome, or 3,5-di-tert-butyl-o-benzoquinone in cells overexpressing QR, especially QR2. These differences could originate from the excretion process, which is different for para- and ortho-quinones. These results are of particular interest in the case of dopamine considering the association of QR2 with various neurological disorders such as Parkinson disease.
Published: 2015

20. Synthesis and Antiplasmodial Activity of New Indolone N-Oxide Derivatives

Author: Karine Reybier, Francesco Turini, Pierre Perio, Hany Ibrahim, Eloise Thompson, Michel Sauvain, Marie-Carmen Monje, Leonardo K. Basco, Serge Petit, Séverine Chevalley, Jean-Pierre Nallet, Sothea Kim, Antonella Pantaleo, Paolo Arese, Barbora Lajoie, Olivier Chatriant, Alexis Valentin, Jeremie Boyer, Rachida Tahar, Françoise Nepveu, Jalloul Bouajila, Eric Deharo, Livia Vivas, Institut de Recherche pour le Développement - IRD (FRANCE), and Université Toulouse III - Paul Sabatier - UT3 (FRANCE)
Subjects: Indoles, Plasmodium berghei, Stereochemistry, Plasmodium falciparum, Biochimie, Biologie Moléculaire, Drug Resistance, Parasitemia, Chemical synthesis, Antimalarials, Structure-Activity Relationship, Parasitic Sensitivity Tests, IndoloneN-Oxide Derivatives, In vivo, Cell Line, Tumor, parasitic diseases, Drug Discovery, Animals, Humans, Cytotoxicity, IC50, chemistry.chemical_classification, biology, Chemistry, Aromatic amine, Oxides, biology.organism_classification, In vitro, Antiplasmodial Activity, Molecular Medicine
Abstract: A series of 66 new indolone-N-oxide derivatives was synthesized with three different methods. Compounds were evaluated for in vitro activity against CQ-sensitive (3D7), CQ-resistant (FcB1), and CQ and pyrimethamine cross-resistant (K1) strains of Plasmodium falciparum (P.f.), as well as for cytotoxic concentration (CC(50)) on MCF7 and KB human tumor cell lines. Compound 26 (5-methoxy-indolone-N-oxide analogue) had the most potent antiplasmodial activity in vitro (3 nM on FcB1 and = 1.7 nM on 3D7) with a very satisfactory selectivity index (CC(50) MCF7/IC(50) FcB1: 14623; CC(50) KB/IC(50) 3D7: 198823). In in vivo experiments, compound 1 (dioxymethylene derivatives of the indolone-N-oxide) showed the best antiplasmodial activity against Plasmodium berghei, 62% inhibition of the parasitaemia at 30 mg/kg/day.
Published: 2009

21. Limited beneficial effects of piceatannol supplementation on obesity complications in the obese Zucker rat: gut microbiota, metabolic, endocrine, and cardiac aspects

Author: Marta Llarena, Luis Bujanda, Luis Aldámiz-Echevarría, Jean-Michel Senard, Maria Jesus Villanueva-Millan, Pierre Perio, Mounia Hasnaoui, F. Leboulanger, Leixuri Aguirre, Fernando Andrade, Elizabeth Hijona, Andrea Mosqueda-Solís, Patricia Pérez-Matute, Jose M. Arbones-Mainar, M. P. Portillo, Françoise Nepveu, Lander Hijona, Christian Carpéné, University of the Basque Country [Bizkaia] (UPV/EHU), Instituto de Salud Carlos III [Madrid] (ISC), Centro de Investigación Biomédica de La Rioja (CIBIR), Institut des Maladies Métaboliques et Cardiovasculaires (I2MC), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut National de la Santé et de la Recherche Médicale (INSERM), Pharmacochimie et Biologie pour le Développement (PHARMA-DEV), Institut de Recherche pour le Développement (IRD)-Institut de Chimie de Toulouse (ICT-FR 2599), Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC), Hospital Universitario Cruces = Cruces University Hospital, CIBER de Enfermedades Raras (CIBERER), Instituto Aragonés de Ciencias de la Salud [Zaragoza] (IACS), Refbio Pyrenees Biomedical Network (POLYFrEsNOL project), Instituto de Salud Carlos III (CIBERobn, CIBERehd, CIBERer), Government of the Basque Country (IT-572-13), University of the Basque Country (UPV/EHU) (ELDUNANOTEK UFI11/32), Instituto Biodonostia, and Fundación Rioja Salud, University of the Basque Country/Euskal Herriko Unibertsitatea (UPV/EHU), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut National de la Santé et de la Recherche Médicale (INSERM), Institut de Recherche pour le Développement (IRD)-Institut de Chimie de Toulouse (ICT), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), and Université de Toulouse (UT)
Subjects: 0301 basic medicine, Male, Physiology, [SDV]Life Sciences [q-bio], Adipose tissue, Gut flora, Resveratrol, Biochemistry, Antioxidants, chemistry.chemical_compound, Mice, Random Allocation, 0302 clinical medicine, Stilbenes, Hyperinsulinemia, Adiposity, Piceatannol, Cardiomyocytes, biology, Anti-Inflammatory Agents, Non-Steroidal, General Medicine, Zucker rat, 3. Good health, Liver, 030220 oncology & carcinogenesis, medicine.medical_specialty, Heart Diseases, Adipose Tissue, White, Adipokine, Context (language use), Hyperlipidemias, Gut microbiota, 03 medical and health sciences, Adipokines, Internal medicine, 3T3-L1 Cells, medicine, Animals, Obesity, Myocardium, Hydrogen Peroxide, medicine.disease, biology.organism_classification, Rats, Zucker, 030104 developmental biology, Endocrinology, chemistry, Dietary Supplements, Dysbiosis, Biomarkers
Abstract: International audience; Resveratrol is beneficial in obese and diabetic rodents. However, its low bioavailability raises questions about its therapeutic relevance for treating or preventing obesity complications. In this context, many related natural polyphenols are being tested for their putative antidiabetic and anti-obesity effects. This prompted us to study the influence of piceatannol, a polyhydroxylated stilbene, on the prevention of obesity complications in Zucker obese rats. A 6-week supplementation was followed by the determination of various markers in plasma, liver, adipose tissue and heart, together with a large-scale analysis of gut microbiota composition. When given in doses of 15 or 45 mg/kg body weight/day, piceatannol did not reduce either hyperphagia or fat accumulation. It did not modify the profusion of the most abundant phyla in gut, though slight changes were observed in the abundance of several Lactobacillus, Clostridium, and Bacteroides species belonging to Firmicutes and Bacteroidetes. This was accompanied by a tendency to reduce plasma lipopolysaccharides by 30 %, and by a decrease of circulating non-esterified fatty acids, LDL-cholesterol, and lactate. While piceatannol tended to improve lipid handling, it did not mitigate hyperinsulinemia and cardiac hypertrophy. However, it increased cardiac expression of ephrin-B1, a membrane protein that contributes to maintaining cardiomyocyte architecture. Lastly, ascorbyl radical plasma levels and hydrogen peroxide release by adipose tissue were similar in control and treated groups. Thus, piceatannol did not exhibit strong slimming capacities but did limit several obesity complications.
Published: 2015

22. Powerful Antioxidant and Pro-Oxidant Properties of Cassia roxburghii DC. Leaves Cultivated in Egypt in Relation to Their Anti-Infectious Activities

Author: Pierre Perio, Hany Ibrahim, Christine Roques, Sahar S. M. El Souda, Christel Henocq-Pigasse, Nehal Ibrahim, Françoise Nepveu, National Research Centre - NRC (EGYPT), Pharmacochimie et Biologie pour le Développement (PHARMA-DEV), Institut de Recherche pour le Développement (IRD)-Institut de Chimie de Toulouse (ICT-FR 2599), Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC), Laboratoire de génie chimique [ancien site de Basso-Cambo] (LGC), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées, Centre National de la Recherche Scientifique - CNRS (FRANCE), Institut National Polytechnique de Toulouse - INPT (FRANCE), Institut de Recherche pour le Développement - IRD (FRANCE), Université Toulouse III - Paul Sabatier - UT3 (FRANCE), National Research Center - NRC (Egypt), Pharmacochimie et Biologie pour le Développement - PHARMA-DEV (Toulouse, France), Institut National Polytechnique de Toulouse - Toulouse INP (FRANCE), Institut de Recherche pour le Développement (IRD)-Institut de Chimie de Toulouse (ICT), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT), Laboratoire de Génie Chimique (LGC), and Université de Toulouse (UT)-Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP)
Subjects: food.ingredient, Antioxidant, DPPH, Radical scavenging, medicine.medical_treatment, Ethyl acetate, Cassia marginata Roxb, Antiplasmodial, chemistry.chemical_compound, food, [CHIM.GENI]Chemical Sciences/Chemical engineering, Enterococcus hirae, medicine, Génie chimique, Petroleum ether, [SPI.GPROC]Engineering Sciences [physics]/Chemical and Process Engineering, Génie des procédés, Pharmacology, biology, Traditional medicine, Chemistry, Aspergillus niger, biology.organism_classification, 6. Clean water, Complementary and alternative medicine, Biochemistry, Cassia roxburghii, Antimicrobial, Antibacterial activity
Abstract: International audience; Leaf extracts of Cassia roxburghii DC., prepared in petroleum ether, chloroform, ethyl acetate, butanol, and methanol/water (70:30, v/v), were evaluated as antioxidant, pro-oxidant, anti-infectious, and cytotoxic agents. The major metabolite of each extract was identified by chromatographic and spectroscopic means. The redox properties were assessed with a battery of assays, which revealed that the ethyl acetate extract demonstrated an interesting scavenging activity of DPPH and superoxide radicals and an ascorbic acid-like pro-oxidant activity. All the tested extracts showed moderate antiplasmodial activity against a chloroquine-resistant strain of Plasmodium falciparum, by possible disruption of parasite fine redox balance. Cytotoxicity was evaluated against a human breast cancer cell line. The antimicrobial activities of the extracts were estimated against representative bacterial strains (Staphylococcus aureus, Enterococcus hirae, Pseudomonas aeruginosa, Escherichia coli) and fungal species (Candida albicans, Aspergillus niger). The ethylacetate extract possessed the highest redox properties and exhibited the highest antiplasmodial activity; there was no correlation between antibacterial activity and the redox properties of the extracts.
Published: 2015

23. Interaction between Antimalarial 2-Aryl-3 H -indol-3-one Derivatives and Human Serum Albumin

Author: Pierre Perio, Nambinina V. Rakotoarivelo, Françoise Nepveu, Ennaji Najahi, Pharmacochimie et Biologie pour le Développement (PHARMA-DEV), Institut de Recherche pour le Développement (IRD)-Institut de Chimie de Toulouse (ICT), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT), Institut de Recherche pour le Développement (IRD)-Institut de Chimie de Toulouse (ICT-FR 2599), Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC)-Institut National Polytechnique (Toulouse) (Toulouse INP), and Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC)
Subjects: Circular dichroism, Indoles, Stereochemistry, Protein Conformation, Ultraviolet Rays, Entropy, [SDV]Life Sciences [q-bio], Plasmodium falciparum, 02 engineering and technology, 010402 general chemistry, 01 natural sciences, Serum Albumin / drug effects, Fluorescence, Hydrophobic effect, Antimalarials, Plasmodium falciparum / drug effects, Materials Chemistry, medicine, Humans, Physical and Theoretical Chemistry, Antimalarials / chemistry, Antimalarials / pharmacology, Serum Albumin, Ions, Indoles / pharmacology, Quenching (fluorescence), Molecular Structure, Chemistry, Indoles / chemistry, Circular Dichroism, Metals / chemistry, Albumin, 021001 nanoscience & nanotechnology, Human serum albumin, Binding constant, Blood proteins, 0104 chemical sciences, Surfaces, Coatings and Films, Metals, Spectrophotometry, Thermodynamics, Ions / chemistry, Serum Albumin / chemistry, 0210 nano-technology, Hydrophobic and Hydrophilic Interactions, medicine.drug
Abstract: International audience; Binding of drugs to plasma proteins, such as albumin, is a major factor which determines their pharmacokinetics and pharmacological effects. Therefore, the interactions between human serum albumin (HSA) and four antimalarial compounds selected in the 2-aryl-3H-indol-3-one series have been investigated using UV-visible, fluorescence and circular dichroism (CD) spectroscopies. Compounds produced a static quenching of the intrinsic fluorescence of HSA. The thermodynamic parameters have shown that the binding reaction is endothermic for three compounds while exothermic for the 2-phenyl-3H-indol-3-one, 3. The interaction is entropically driven with predominant hydrophobic forces with binding affinities of the order of 10(4) M(-1). The highest binding constant is observed for 3 (Kλ=280nm = 4.53 × 10(4) M(-1)) which is also the less active compound against Plasmodium falciparum. Synchronous fluorescence gave qualitative information on the conformational changes of HSA while quantitative data were obtained with CD. Displacement experiments with site markers indicated that drugs bind to HSA at site I (subdomain IIA). In addition, the apparent binding constant and the binding site number were calculated in the presence of different ions.
Published: 2014

24. Pro-oxidant properties of indolone-N-oxides in relation to their antimalarial properties

Author: Hany Ibrahim, Pierre Perio, Karine Reybier, Ennaji Najahi, Paul-Louis Fabre, Florence Souard, Françoise Nepveu, Nguyen Thi Hoang Yen, University of Medicine and Pharmacy (VIETNAM), Pharmacochimie et Biologie pour le Développement (PHARMA-DEV), Institut de Recherche pour le Développement (IRD)-Institut de Chimie de Toulouse (ICT-FR 2599), Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC), Laboratoire de génie chimique [ancien site de Basso-Cambo] (LGC), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées, Centre National de la Recherche Scientifique - CNRS (FRANCE), Institut National Polytechnique de Toulouse - Toulouse INP (FRANCE), Institut de Recherche pour le Développement - IRD (FRANCE), Université Toulouse III - Paul Sabatier - UT3 (FRANCE), Laboratoire de Génie Chimique - LGC (Toulouse, France), Institut National Polytechnique de Toulouse - INPT (FRANCE), Institut de Recherche pour le Développement (IRD)-Institut de Chimie de Toulouse (ICT), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT), Laboratoire de Génie Chimique (LGC), and Université de Toulouse (UT)-Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP)
Subjects: Indolone-N-oxides, Indoles, Cyclic voltammetry, Syk, Pharmacologie, 01 natural sciences, Biochemistry, [CHIM.GENI]Chemical Sciences/Chemical engineering, Pro-oxidant drugs, Electron paramagnetic resonance (EPR), Host cell membrane, biology, Chemistry, Intracellular Signaling Peptides and Proteins, Chloroquine, Protein-Tyrosine Kinases, Artemisinins, 3. Good health, Solutions, Hemin, medicine.symptom, Oxidation-Reduction, Tyrosine kinase, Iron, Radical, Heme, 010402 general chemistry, Models, Biological, Redox, Cyclic N-Oxides, Inorganic Chemistry, Antimalarials, medicine, Humans, Syk Kinase, Génie chimique, Cysteine, 010405 organic chemistry, Erythrocyte Membrane, Electron Spin Resonance Spectroscopy, Plasmodium falciparum, Pro-oxidant, biology.organism_classification, 0104 chemical sciences, Enzyme Activation, Models, Chemical, Mechanism of action, [SDV.SP.PHARMA]Life Sciences [q-bio]/Pharmaceutical sciences/Pharmacology, Antimalarial drugs, Reactive Oxygen Species
Abstract: International audience; Indolone-N-oxides (INODs) are bioreducible and possess remarkable anti-malarial activities in the low nanomolar range in vitro against different Plasmodium falciparum (P. falciparum) strains and in vivo. INODs have an original mechanism of action: they damage the host cell membrane without affecting non-parasitized erythrocytes. These molecules produce a redox signal which activates SYK tyrosine kinases and induces a hyperphosphorylation of AE1 (band 3, erythrocyte membrane protein). The present work aimed to understand the early stages of the biochemical interactions of these compounds with some erythrocyte components from which the redox signal could originate. The interactions were studied in a biomimetic model and compared with those of chloroquine and artemisinin. The results showed that INODs i) do not enter the coordination sphere of the metal in the heme iron complex as does chloroquine; ii) do not generate iron-dependent radicals as does artemisinin; iii) generate stable free radical adducts after reduction at one electron; iv) cannot trap free radicals after reduction. These results confirm that the bioactivity of INODs does not lie in their spin-trapping properties but rather in their pro-oxidant character. This property may be the initiator of the redox signal which activates SYK tyrosine kinases.
Published: 2013

25. Behavior of N-oxide derivatives in atmospheric pressure ionization mass spectrometry

Author: Hany, Ibrahim, François, Couderc, Pierre, Perio, Fabrice, Collin, and Françoise, Nepveu
Subjects: Oxygen, Antimalarials, Spectrometry, Mass, Electrospray Ionization, Atmospheric Pressure, Indoles, Tandem Mass Spectrometry, Methanol, Nebulizers and Vaporizers, Hydroxyquinolines, Temperature, Oxides, Gases
Abstract: Indolone-N-oxide derivatives possess interesting biological properties. The analysis of these compounds using mass spectrometry (MS) may lead to interference or under-estimation due to the tendency of the N-oxides to lose oxygen. All the previous works focused only on the temperature of the heated parts (vaporizer and ion-transfer tube) of the mass spectrometer without investigating other parameters. This work is extended to the investigation of other parameters.The behavior of N-oxides during atmospheric pressure chemical ionization (APCI) and electrospray ionization (ESI) has been investigated using MS(n) ion trap mass spectrometry. Different parameters were investigated to clarify the factors implicated in the deoxygenation process. The investigated parameters were vaporizer temperature (APCI), ion-transfer tube temperature, solvent type, and the flow rates of the sheath gas, auxiliary gas, sweep gas and mobile phase.The deoxygenation increased when the vaporizer temperature increased. The extent of the 'thermally' induced deoxygenation was inversely proportional to the ion-transfer tube temperature and auxiliary gas flow rate and in direct proportion to the mobile phase flow rate. Deoxygenation was not detected under MS/MS fragmentation and hence it is a non-collision-induced dissociation. N-Oxides have the tendency to form abundant 'non-classical' dimers under ESI, which fragment via dehydration rather than giving their corresponding monomer.Deoxygenation is not solely a 'classical' thermal process but it is a thermal process that is solvent-mediated in the source. Deoxygenation was maximal with an APCI source while dimerization was predominant with an ESI source. Therefore, attention should be paid to these molecular changes in the mass spectrometer as well as to the choice of the ionization mode for N-oxides.
Published: 2012

26. Insights into the redox cycle of human quinone reductase 2

Author: Karine Reybier, Gilles Ferry, Jalloul Bouajila, Françoise Nepveu, Philippe Delagrange, Pierre Perio, and Jean A. Boutin
Subjects: Free Radicals, Stereochemistry, Radical, Aziridines, Antineoplastic Agents, Oxidative phosphorylation, Reductase, Photochemistry, Biochemistry, Substrate Specificity, chemistry.chemical_compound, Mice, Quinone Reductases, Menadione, Animals, Humans, Prodrugs, Enzyme Inhibitors, Binding Sites, Electron Spin Resonance Spectroscopy, Substrate (chemistry), General Medicine, Hydrogen Peroxide, Quinone, chemistry, Hydroxyl radical, Oxidation-Reduction
Abstract: NRH:quinone oxidoreductase 2 (QR2) is a cytosolic enzyme that catalyzes the reduction of quinones, such as menadione and co-enzymes Q. With the aim of understanding better the mechanisms of action of QR2, we approached this enzyme catalysis via electron paramagnetic resonance (EPR) measurements of the by-products of the QR2 redox cycle. The variation in the production of oxidative species such as H(2)O(2), and subsequent hydroxyl radical generation, was measured during the course of QR2 activity under aerobic conditions and using pure human enzyme. The effects on the activity of the following were compared: (i) synthetic (N-benzyldihydronicotinamide, BNAH) or natural (nicotinamide riboside, NRH) co-substrates; (ii) synthetic (menadione) or natural (co-enzyme Q0, Q2) substrates; (iii) QR2 modulators and inhibitors (melatonin, resveratrol and S29434); (iv) a pro-drug activated via a redox cycle [CB1954, 5-(aziridin-1-yl)-2,4-dinitrobenzamide]. The results were also compared with those obtained with human QR1. The production of hydroxyl radicals is: (i) observed whatever the substrate/co-substrate used; ii) quenched by adding catalase; (iii) not observed with the specific QR2 inhibitor S29434; (iv) observed with the pro-drug CB1954. While QR2 produced free radicals with this pro-drug, QR1 gave no EPR signal showing the strong reducing capacity of QR2. In conclusion, EPR analysis of QR2 enzyme activity through free radical production enables modulators and effective inhibitors to be distinguished.
Published: 2011

27. Synthesis and Antiplasmodial Activity of New Indolone N-Oxide Derivatives.

Author: FrancÌ§oise Nepveu, Sothea Kim, Jeremie Boyer, Olivier Chatriant, Hany Ibrahim, Karine Reybier, Marie-Carmen Monje, Severine Chevalley, Pierre Perio, Barbora H. Lajoie, Jalloul Bouajila, Eric Deharo, Michel Sauvain, Rachida Tahar, Leonardo Basco, Antonella Pantaleo, Francesco Turini, Paolo Arese, Alexis Valentin, and Eloise Thompson
Published: 2010
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28. Antiphases Periodiques à Periodes non Entières

Author: Abraham Hauptman, Pierre Perio, Hiroshi Okuzumi, Max Tournarie, and Romain Kleinberger
Subjects: Diffraction, Simple (abstract algebra), Diagram, General Physics and Astronomy, Statistical physics, Mathematics, Terminology, Theory based
Abstract: This paper proposes a theory based on statistical considerations, leading to a simple classification of the diffraction diagrams of antiphase with non-integral periods. In comparing it with previous studies, we attempt to clarify apparent differences due to terminology. It appears that several different models can have the same qualitative diffraction diagram, and that only quantitative measurements, difficult to make and to interpret, can distinguish amongst them.
Published: 1962

29. Preparation et dosage, avec une precision superieure au millieme, de solutions d'acide borique deutere dans l'eau lourde

Author: François-Michel Lang, Romain Kleinberger, Cécile Finck, Pierre Perio, and Pierre Magnier
Subjects: Boric acid, Heavy water, chemistry.chemical_compound, Deuterium, Chemistry, General Engineering, chemistry.chemical_element, Boron, Calcium borate, Nuclear chemistry
Abstract: Solutions of deuterated boric acid in heavy water have been prepared with concentrations known to within 0·1 %. They were made from very pure boric anhydride, obtained by dehydrating boric acid, using a vacuum thermobalance (Eyruad type). The solutions are analysed by weighing calcium borate.
Published: 1956

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29 results on '"Pierre Perio"'

1. Association of NQO2 With UDP-Glucuronosyltransferases Reduces Menadione Toxicity in Neuroblastoma Cells

2. Effect of Artemisinin-Loaded Mesoporous Cerium-Doped Calcium Silicate Nanopowder on Cell Proliferation of Human Periodontal Ligament Fibroblasts

3. Effect of Artemisinin-Loaded Mesoporous Cerium-Doped Calcium Silicate Nanopowder on Cell Proliferation of Human Periodontal Ligament Fibroblasts

4. The Clitocybins and 2-Substituted-Isoindolin-1-Ones: Synthesis and in Vitro Antimycobacterial Activities

5. Superoxide: A major role in the mechanism of action of essential antimalarial drugs

6. Effect of ion doping in silica-based nanoparticles on the hemolytic and oxidative activity in contact with human erythrocytes

7. Electrochemical and Spin-Trapping Properties of para-substituted α-Phenyl-N-tert-butyl Nitrones

8. Synthesis and Evaluation of Antiplasmodial Activities of Fluorinated 6-Amino- 2-Aryl-3H-Indolone-N-Oxides

9. LUCS (Light-Up Cell System), a universal high throughput assay for homeostasis evaluation in live cells

10. Oxidative stress and neurodegeneration: The possible contribution of quinone reductase 2

11. Dereplication of natural products from complex extracts by regression analysis and molecular networking: case study of redox-active compounds from Viola alba subsp. dehnhardtii

12. Role of quinone reductase 2 in the antimalarial properties of indolone-type derivatives

13. ISOINDOLINOTRIAZOLE DERIVATIVES: SYNTHESIS BY THE AZIDE-ALKYNE CYCLOADDITION CLICK CHEMISTRY

14. EPR Spectroelectrochemical Investigation of Guanine Radical Formation and Environment Effects

15. Behavior ofN-oxide derivatives in atmospheric pressure ionization mass spectrometry

16. Electrochemical behavior of indolone-N-oxides: Relationship to structure and antiplasmodial activity

17. LC-MS based metabolomic approach applied to bioactive molecules identification: case study of a comprehesive chemodiversity screening of Viola genus

18. Evolution, radiation and chemotaxonomy of Lamellodysidea, a demosponge genus with anti-plasmodial metabolites

19. In cellulo monitoring of quinone reductase activity and reactive oxygen species production during the redox cycling of 1,2 and 1,4 quinones

20. Synthesis and Antiplasmodial Activity of New Indolone N-Oxide Derivatives

21. Limited beneficial effects of piceatannol supplementation on obesity complications in the obese Zucker rat: gut microbiota, metabolic, endocrine, and cardiac aspects

22. Powerful Antioxidant and Pro-Oxidant Properties of Cassia roxburghii DC. Leaves Cultivated in Egypt in Relation to Their Anti-Infectious Activities

23. Interaction between Antimalarial 2-Aryl-3 H -indol-3-one Derivatives and Human Serum Albumin

24. Pro-oxidant properties of indolone-N-oxides in relation to their antimalarial properties

25. Behavior of N-oxide derivatives in atmospheric pressure ionization mass spectrometry

26. Insights into the redox cycle of human quinone reductase 2

27. Synthesis and Antiplasmodial Activity of New Indolone N-Oxide Derivatives.

28. Antiphases Periodiques à Periodes non Entières

29. Preparation et dosage, avec une precision superieure au millieme, de solutions d'acide borique deutere dans l'eau lourde

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29 results on '"Pierre Perio"'

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