You will find below the list of publications of all the members of the Peptides, Glycoconjugates and Metals in Biology research pole. For individual or theme-specific publications, please consult the research or the personal pages via the members list using the sidebar navigation tool.
2015 |
Translocation mechanism(s) of cell-penetrating peptides: Biophysical studies using artificial membrane bilayers Article de journal M Di Pisa; G Chassaing; J -M Swiecicki Biochemistry, 54 (2), p. 194–207, 2015. @article{DiPisa:2015, title = {Translocation mechanism(s) of cell-penetrating peptides: Biophysical studies using artificial membrane bilayers}, author = {M Di Pisa and G Chassaing and J -M Swiecicki}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84922460774&doi=10.1021%2fbi501392n&partnerID=40&md5=1db43792ad7a040df53aeea78d26aecc}, doi = {10.1021/bi501392n}, year = {2015}, date = {2015-01-01}, journal = {Biochemistry}, volume = {54}, number = {2}, pages = {194--207}, abstract = {The ability of cell-penetrating peptides (CPPs) to cross cell membranes has found numerous applications in the delivery of bioactive compounds to the cytosol of living cells. Their internalization mechanisms have been questioned many times, and after 20 years of intense debate, it is now widely accepted that both energy-dependent and energy-independent mechanisms account for their penetration properties. However, the energy-independent mechanisms, named "direct translocation", occurring without the requirement of the cell internalization machinery, remain to be fully rationalized at the molecular level. Using artificial membrane bilayers, recent progress has been made toward the comprehension of the direct translocation event. This review summarizes our current understanding of the translocation process, starting from the adsorption of the CPP on the membrane to the membrane crossing itself. We describe the different key steps occurring before direct translocation, because each of them can promote and/or hamper translocation of the CPP through the membrane. We then dissect the modification to the membranes induced by the presence of the CPPs. Finally, we focus on the latest studies describing the direct translocation mechanisms. These results provide an important framework within which to design new CPPs and to rationalize an eventual selectivity of CPPs in their penetration ability. © 2014 American Chemical Society.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The ability of cell-penetrating peptides (CPPs) to cross cell membranes has found numerous applications in the delivery of bioactive compounds to the cytosol of living cells. Their internalization mechanisms have been questioned many times, and after 20 years of intense debate, it is now widely accepted that both energy-dependent and energy-independent mechanisms account for their penetration properties. However, the energy-independent mechanisms, named "direct translocation", occurring without the requirement of the cell internalization machinery, remain to be fully rationalized at the molecular level. Using artificial membrane bilayers, recent progress has been made toward the comprehension of the direct translocation event. This review summarizes our current understanding of the translocation process, starting from the adsorption of the CPP on the membrane to the membrane crossing itself. We describe the different key steps occurring before direct translocation, because each of them can promote and/or hamper translocation of the CPP through the membrane. We then dissect the modification to the membranes induced by the presence of the CPPs. Finally, we focus on the latest studies describing the direct translocation mechanisms. These results provide an important framework within which to design new CPPs and to rationalize an eventual selectivity of CPPs in their penetration ability. © 2014 American Chemical Society. |
Nanometric distance measurements between Mn(II)DOTA centers Article de journal H Y Vincent Ching; P Demay-Drouhard; H C Bertrand; C Policar; L C Tabares; S Un Physical Chemistry Chemical Physics, 17 (36), p. 23368–23377, 2015. @article{VincentChing:2015, title = {Nanometric distance measurements between Mn(II)DOTA centers}, author = {H Y Vincent Ching and P Demay-Drouhard and H C Bertrand and C Policar and L C Tabares and S Un}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84941299721&doi=10.1039%2fc5cp03487f&partnerID=40&md5=bfd7a9aac0fc115147eb207f0fbeb05b}, doi = {10.1039/c5cp03487f}, year = {2015}, date = {2015-01-01}, journal = {Physical Chemistry Chemical Physics}, volume = {17}, number = {36}, pages = {23368--23377}, abstract = {Pulse electron-electron double resonance (PELDOR) is a versatile technique for probing the structures and functions of complex biological systems. Despite the recent interest in high-spin metal-ions for high field/frequency applications, PELDOR measurements of Mn(II) remain relatively underexplored. Here we present Mn(II)-Mn(II) PELDOR distance measurements at 94 GHz on polyproline II (PPII) helices doubly spin-labeled with Mn(II)DOTA, which are distinguished by their small zero-field interaction. The measured Mn-Mn distances and distribution profiles were in good agreement with the expected values from molecular models. Additional features in the frequency-domain spectra became apparent at certain combinations of detect and pump frequencies. Spin-Hamiltonian calculations showed that they likely arose from contributions from the pseudo-secular component of the dipolar interaction that were found to be non-negligible for Mn(II)DOTA. However, the influence of the pseudo-secular component on the distance distribution profiles apparently was limited. The results show the potential of Mn(II)DOTA spin labels for high-field PELDOR distance measurements in proteins and other biological systems. © the Owner Societies 2015.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Pulse electron-electron double resonance (PELDOR) is a versatile technique for probing the structures and functions of complex biological systems. Despite the recent interest in high-spin metal-ions for high field/frequency applications, PELDOR measurements of Mn(II) remain relatively underexplored. Here we present Mn(II)-Mn(II) PELDOR distance measurements at 94 GHz on polyproline II (PPII) helices doubly spin-labeled with Mn(II)DOTA, which are distinguished by their small zero-field interaction. The measured Mn-Mn distances and distribution profiles were in good agreement with the expected values from molecular models. Additional features in the frequency-domain spectra became apparent at certain combinations of detect and pump frequencies. Spin-Hamiltonian calculations showed that they likely arose from contributions from the pseudo-secular component of the dipolar interaction that were found to be non-negligible for Mn(II)DOTA. However, the influence of the pseudo-secular component on the distance distribution profiles apparently was limited. The results show the potential of Mn(II)DOTA spin labels for high-field PELDOR distance measurements in proteins and other biological systems. © the Owner Societies 2015. |
Synthesis, characterization and biological activity of Cu(II), Zn(II) and Re(I) complexes derived from S-benzyldithiocarbazate and 3-acetylcoumarin Article de journal M L Low; G Paulus; P Dorlet; R Guillot; R Rosli; N Delsuc; K A Crouse; C Policar BioMetals, 28 (3), p. 553–566, 2015. @article{Low:2015, title = {Synthesis, characterization and biological activity of Cu(II), Zn(II) and Re(I) complexes derived from S-benzyldithiocarbazate and 3-acetylcoumarin}, author = {M L Low and G Paulus and P Dorlet and R Guillot and R Rosli and N Delsuc and K A Crouse and C Policar}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84939939059&doi=10.1007%2fs10534-015-9831-2&partnerID=40&md5=8d0220a2a88cc9eb122f191d65c87199}, doi = {10.1007/s10534-015-9831-2}, year = {2015}, date = {2015-01-01}, journal = {BioMetals}, volume = {28}, number = {3}, pages = {553--566}, abstract = {Cu(II), Zn(II) and Re(I) complexes have been synthesized with the Schiff base, N′-[1-(2-oxo-2H-chromen-3-yl)-ethylidene]-hydrazinecarbodithioic acid benzyl ester (SBCM-H) which was prepared by condensation of S-benzyldithiocarbazate and 3-acetylcoumarin. The metal complexes were characterized on the basis of various physico-chemical and spectroscopic techniques including elemental analysis and electrochemical studies, and FT-IR, UV-Vis, NMR, EPR and mass spectroscopy. The Schiff base was found to behave as a bidentate ligand coordinating with Cu(II) and Zn(II) in the thiolate form with 1:2 metal to ligand stoichiometry. Crystals suitable for X-ray diffractometry (XRD) were obtained from the reaction of ReCl(CO)5 with SBCM-H forming a centrosymmetric dimeric complex Re2L2(CO)6 linked by Re-S-Re bridges, where S is the thiolate sulfur of the N,S-bidentate ligand. This Re(I) complex is the first metal carbonyl complex with a bidentate dithiocarbazate ligand to have been characterized by XRD. Cytotoxicity assays revealed enhancement of the bioactivity of SBCM-H upon complexation. Both Cu(II) and Re(I) complexes are found to be active against human breast adenocarcinoma cancer cell lines MDA-MB-231 and MCF-7. Graphical Abstract: TOC diagram [Figure not available: see fulltext.] © 2015 Springer Science+Business Media New York.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Cu(II), Zn(II) and Re(I) complexes have been synthesized with the Schiff base, N′-[1-(2-oxo-2H-chromen-3-yl)-ethylidene]-hydrazinecarbodithioic acid benzyl ester (SBCM-H) which was prepared by condensation of S-benzyldithiocarbazate and 3-acetylcoumarin. The metal complexes were characterized on the basis of various physico-chemical and spectroscopic techniques including elemental analysis and electrochemical studies, and FT-IR, UV-Vis, NMR, EPR and mass spectroscopy. The Schiff base was found to behave as a bidentate ligand coordinating with Cu(II) and Zn(II) in the thiolate form with 1:2 metal to ligand stoichiometry. Crystals suitable for X-ray diffractometry (XRD) were obtained from the reaction of ReCl(CO)5 with SBCM-H forming a centrosymmetric dimeric complex Re2L2(CO)6 linked by Re-S-Re bridges, where S is the thiolate sulfur of the N,S-bidentate ligand. This Re(I) complex is the first metal carbonyl complex with a bidentate dithiocarbazate ligand to have been characterized by XRD. Cytotoxicity assays revealed enhancement of the bioactivity of SBCM-H upon complexation. Both Cu(II) and Re(I) complexes are found to be active against human breast adenocarcinoma cancer cell lines MDA-MB-231 and MCF-7. Graphical Abstract: TOC diagram [Figure not available: see fulltext.] © 2015 Springer Science+Business Media New York. |
Metal-carbonyl units for vibrational and luminescence imaging: Towards multimodality Article de journal S Clède; C Policar Chemistry - A European Journal, 21 (3), p. 942–958, 2015. @article{Clede:2015, title = {Metal-carbonyl units for vibrational and luminescence imaging: Towards multimodality}, author = {S Cl\`{e}de and C Policar}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84920784874&doi=10.1002%2fchem.201404600&partnerID=40&md5=eaf7654638733b121ed1fe744e71b7b5}, doi = {10.1002/chem.201404600}, year = {2015}, date = {2015-01-01}, journal = {Chemistry - A European Journal}, volume = {21}, number = {3}, pages = {942--958}, abstract = {Metal-carbonyl complexes are attractive structures for bio-imaging. In addition to unique vibrational properties due to the CO moieties enabling IR and Raman cell imaging, the appropriate choice of ancillary ligands opens up the opportunity for luminescence detection. Through a classification by techniques, past and recent developments in the application of metal-carbonyl complexes for vibrational and luminescence bio-imaging are reviewed. Finally, their potential as bimodal IR and luminescent probes is addressed. © 2015 Wiley-VCH Verlag GmbH & Co. KGaA.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Metal-carbonyl complexes are attractive structures for bio-imaging. In addition to unique vibrational properties due to the CO moieties enabling IR and Raman cell imaging, the appropriate choice of ancillary ligands opens up the opportunity for luminescence detection. Through a classification by techniques, past and recent developments in the application of metal-carbonyl complexes for vibrational and luminescence bio-imaging are reviewed. Finally, their potential as bimodal IR and luminescent probes is addressed. © 2015 Wiley-VCH Verlag GmbH & Co. KGaA. |
An easy-to-detect nona-arginine peptide for epidermal targeting Article de journal S Clède; N Delsuc; C Laugel; F Lambert; C Sandt; A Baillet-Guffroy; C Policar Chemical Communications, 51 (13), p. 2687–2689, 2015. @article{Clede:2015a, title = {An easy-to-detect nona-arginine peptide for epidermal targeting}, author = {S Cl\`{e}de and N Delsuc and C Laugel and F Lambert and C Sandt and A Baillet-Guffroy and C Policar}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84922637409&doi=10.1039%2fc4cc08737b&partnerID=40&md5=a0e333e8498570e4d4ceb500066d9c1e}, doi = {10.1039/c4cc08737b}, year = {2015}, date = {2015-01-01}, journal = {Chemical Communications}, volume = {51}, number = {13}, pages = {2687--2689}, abstract = {A correlative approach combining synchrotron radiation based IR microscopy and fluorescence microscopy enabled the successful detection and quantification of a nona-arginine peptide labelled with a Single Core Multimodal Probe for Imaging (SCoMPI) in skin biopsies. The topical penetration of the conjugate appeared to be time dependent and occurred most probably via the extracellular matrix. This journal is © The Royal Society of Chemistry 2015.}, keywords = {}, pubstate = {published}, tppubtype = {article} } A correlative approach combining synchrotron radiation based IR microscopy and fluorescence microscopy enabled the successful detection and quantification of a nona-arginine peptide labelled with a Single Core Multimodal Probe for Imaging (SCoMPI) in skin biopsies. The topical penetration of the conjugate appeared to be time dependent and occurred most probably via the extracellular matrix. This journal is © The Royal Society of Chemistry 2015. |
Fast magnetically driven electrodeposition of amorphous metal oxide water oxidation catalysts from carbon-coated metallic nanoparticles Article de journal J Zhu; F Lambert; C Policar; F Mavré; B Limoges Journal of Materials Chemistry A, 3 (31), p. 16190–16197, 2015. @article{Zhu:2015, title = {Fast magnetically driven electrodeposition of amorphous metal oxide water oxidation catalysts from carbon-coated metallic nanoparticles}, author = {J Zhu and F Lambert and C Policar and F Mavr\'{e} and B Limoges}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84938100019&doi=10.1039%2fc5ta03430b&partnerID=40&md5=ac4e0e0dc5c94a4c574b14d5b17ac552}, doi = {10.1039/c5ta03430b}, year = {2015}, date = {2015-01-01}, journal = {Journal of Materials Chemistry A}, volume = {3}, number = {31}, pages = {16190--16197}, abstract = {We report a new approach for efficient electrodeposition of amorphous metal oxide water oxidation catalysts on an electrode surface. A catalytic metal-based film was obtained by means of anodic oxidation of metallic nanoparticles, namely carbon-coated cobalt nanoparticles or carbon-coated nickel nanoparticles. Interestingly, these particles are intrinsically conductive and possess magnetic properties which make it easy to collect them on an electrode surface using a simple magnet to form a porous conductive particulate film. Upon anodic polarization in an appropriate electrolyte, the particulate film is rapidly converted into an amorphous metal-based catalytic film that efficiently catalyzes the oxidation of water at neutral pH. Compared to Nocera's method based on anodic electrodeposition of a metal salt in solution, this new electrodeposition strategy offers the key advantage of supplying metal ions in a solid and metallic form, leading to a fast release of high local concentrations of metal ions right at the spot of the film formation (i.e., in the vicinity of the electrode surface). This plays a decisive role in the formation rate of the catalytic film, allowing the deposition of the oxygen-evolving catalyst in a remarkably short-time. Moreover, the methodology can be easily extended to a wide range of metal particles of different nature and sizes, and also to their mixtures, finally offering a new degree of flexibility and opportunities not only in the preparation of metal-based water oxidation catalysts, but also in the preparation of inorganic metal-based catalysts for hydrogen or oxygen evolution. © 2015 The Royal Society of Chemistry.}, keywords = {}, pubstate = {published}, tppubtype = {article} } We report a new approach for efficient electrodeposition of amorphous metal oxide water oxidation catalysts on an electrode surface. A catalytic metal-based film was obtained by means of anodic oxidation of metallic nanoparticles, namely carbon-coated cobalt nanoparticles or carbon-coated nickel nanoparticles. Interestingly, these particles are intrinsically conductive and possess magnetic properties which make it easy to collect them on an electrode surface using a simple magnet to form a porous conductive particulate film. Upon anodic polarization in an appropriate electrolyte, the particulate film is rapidly converted into an amorphous metal-based catalytic film that efficiently catalyzes the oxidation of water at neutral pH. Compared to Nocera's method based on anodic electrodeposition of a metal salt in solution, this new electrodeposition strategy offers the key advantage of supplying metal ions in a solid and metallic form, leading to a fast release of high local concentrations of metal ions right at the spot of the film formation (i.e., in the vicinity of the electrode surface). This plays a decisive role in the formation rate of the catalytic film, allowing the deposition of the oxygen-evolving catalyst in a remarkably short-time. Moreover, the methodology can be easily extended to a wide range of metal particles of different nature and sizes, and also to their mixtures, finally offering a new degree of flexibility and opportunities not only in the preparation of metal-based water oxidation catalysts, but also in the preparation of inorganic metal-based catalysts for hydrogen or oxygen evolution. © 2015 The Royal Society of Chemistry. |
Entasis through Hook-and-Loop fastening in a glycoligand with cumulative weak forces stabilizing CuI Article de journal L Garcia; F Cisnetti; N Gillet; R Guillot; M Aumont-Nicaise; J -P Piquemal; M Desmadril; F Lambert; C Policar Journal of the American Chemical Society, 137 (3), p. 1141–1146, 2015. @article{Garcia:2015, title = {Entasis through Hook-and-Loop fastening in a glycoligand with cumulative weak forces stabilizing CuI}, author = {L Garcia and F Cisnetti and N Gillet and R Guillot and M Aumont-Nicaise and J -P Piquemal and M Desmadril and F Lambert and C Policar}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84921832039&doi=10.1021%2fja510259p&partnerID=40&md5=eb31b469985f0f4759bf0f0869f067c9}, doi = {10.1021/ja510259p}, year = {2015}, date = {2015-01-01}, journal = {Journal of the American Chemical Society}, volume = {137}, number = {3}, pages = {1141--1146}, abstract = {The idea of a possible control of metal ion properties by constraining the coordination sphere geometry was introduced by Vallee and Williams with the concept of entasis, which is frequently postulated to be at stake in metallobiomolecules. However, the interactions controlling the geometry at metal centers remain often elusive. In this study, the coordination properties toward copper ions - CuII or CuI - of a geometrically constrained glycoligand centered on a sugar scaffold were compared with those of an analogous ligand built on an unconstrained alkyl chain. The sugar-centered ligand was shown to be more preorganized for CuII coordination than its open-chain analogue, with an unusual additional stabilization of the CuI redox state. This preference for CuI was suggested to arise from geometric constraints favoring an optimized folding of the glycoligand minimizing steric repulsions. In other words, the CuI d10 species is stabilized by valence shell electron pair repulsion (VSEPR). This idea was rationalized by a theoretical noncovalent interactions (NCI) analysis. The cumulative effects of weak forces were shown to create an efficient buckle as in a hook-and-loop fastener, and fine structural features within the glycoligand reduce repulsive interactions for the CuI state. This study emphasizes that monosaccharide platforms are appropriate ligand backbones for a delicate geometric control at the metal center, with a network of weak interactions within the ligand. This structuration availing in glycoligands makes them attractive for metallic entasis. © 2015 American Chemical Society.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The idea of a possible control of metal ion properties by constraining the coordination sphere geometry was introduced by Vallee and Williams with the concept of entasis, which is frequently postulated to be at stake in metallobiomolecules. However, the interactions controlling the geometry at metal centers remain often elusive. In this study, the coordination properties toward copper ions - CuII or CuI - of a geometrically constrained glycoligand centered on a sugar scaffold were compared with those of an analogous ligand built on an unconstrained alkyl chain. The sugar-centered ligand was shown to be more preorganized for CuII coordination than its open-chain analogue, with an unusual additional stabilization of the CuI redox state. This preference for CuI was suggested to arise from geometric constraints favoring an optimized folding of the glycoligand minimizing steric repulsions. In other words, the CuI d10 species is stabilized by valence shell electron pair repulsion (VSEPR). This idea was rationalized by a theoretical noncovalent interactions (NCI) analysis. The cumulative effects of weak forces were shown to create an efficient buckle as in a hook-and-loop fastener, and fine structural features within the glycoligand reduce repulsive interactions for the CuI state. This study emphasizes that monosaccharide platforms are appropriate ligand backbones for a delicate geometric control at the metal center, with a network of weak interactions within the ligand. This structuration availing in glycoligands makes them attractive for metallic entasis. © 2015 American Chemical Society. |
2014 |
Synthesis and evaluation of analogues of N-phthaloyl-l-tryptophan (RG108) as inhibitors of DNA methyltransferase 1 Article de journal S Asgatay; C Champion; G Marloie; T Drujon; C Senamaud-Beaufort; A Ceccaldi; A Erdmann; A Rajavelu; P Schambel; A Jeltsch; O Lequin; P Karoyan; P B Arimondo; D Guianvarc'H Journal of Medicinal Chemistry, 57 (2), p. 421–434, 2014. @article{Asgatay:2014, title = {Synthesis and evaluation of analogues of N-phthaloyl-l-tryptophan (RG108) as inhibitors of DNA methyltransferase 1}, author = {S Asgatay and C Champion and G Marloie and T Drujon and C Senamaud-Beaufort and A Ceccaldi and A Erdmann and A Rajavelu and P Schambel and A Jeltsch and O Lequin and P Karoyan and P B Arimondo and D Guianvarc'H}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84893061501&doi=10.1021%2fjm401419p&partnerID=40&md5=a415785b6c3470a947f50df0809ffe02}, doi = {10.1021/jm401419p}, year = {2014}, date = {2014-01-01}, journal = {Journal of Medicinal Chemistry}, volume = {57}, number = {2}, pages = {421--434}, abstract = {DNA methyltransferases (DNMT) are promising drug targets in cancer provided that new, more specific, and chemically stable inhibitors are discovered. Among the non-nucleoside DNMT inhibitors, N-phthaloyl-l-tryptophan 1 (RG108) was first identified as inhibitor of DNMT1. Here, 1 analogues were synthesized to understand its interaction with DNMT. The indole, carboxylate, and phthalimide moieties were modified. Homologated and conformationally constrained analogues were prepared. The latter were synthesized from prolinohomotryptophan derivatives through a methodology based amino-zinc-ene-enolate cyclization. All compounds were tested for their ability to inhibit DNMT1 in vitro. Among them, constrained compounds 16-18 and NPys derivatives 10-11 were found to be at least 10-fold more potent than the reference compound. The cytotoxicity on the tumor DU145 cell line of the most potent inhibitors was correlated to their inhibitory potency. Finally, docking studies were conducted in order to understand their binding mode. This study provides insights for the design of the next-generation of DNMT inhibitors. © 2013 American Chemical Society.}, keywords = {}, pubstate = {published}, tppubtype = {article} } DNA methyltransferases (DNMT) are promising drug targets in cancer provided that new, more specific, and chemically stable inhibitors are discovered. Among the non-nucleoside DNMT inhibitors, N-phthaloyl-l-tryptophan 1 (RG108) was first identified as inhibitor of DNMT1. Here, 1 analogues were synthesized to understand its interaction with DNMT. The indole, carboxylate, and phthalimide moieties were modified. Homologated and conformationally constrained analogues were prepared. The latter were synthesized from prolinohomotryptophan derivatives through a methodology based amino-zinc-ene-enolate cyclization. All compounds were tested for their ability to inhibit DNMT1 in vitro. Among them, constrained compounds 16-18 and NPys derivatives 10-11 were found to be at least 10-fold more potent than the reference compound. The cytotoxicity on the tumor DU145 cell line of the most potent inhibitors was correlated to their inhibitory potency. Finally, docking studies were conducted in order to understand their binding mode. This study provides insights for the design of the next-generation of DNMT inhibitors. © 2013 American Chemical Society. |
A proapoptotic peptide conjugated to penetratin selectively inhibits tumor cell growth Article de journal I D Alves; M Carré; M -P Montero; S Castano; S Lecomte; R Marquant; P Lecorché; F Burlina; C Schatz; S Sagan; G Chassaing; D Braguer; S Lavielle Biochimica et Biophysica Acta - Biomembranes, 1838 (8), p. 2087–2098, 2014. @article{Alves:2014, title = {A proapoptotic peptide conjugated to penetratin selectively inhibits tumor cell growth}, author = {I D Alves and M Carr\'{e} and M -P Montero and S Castano and S Lecomte and R Marquant and P Lecorch\'{e} and F Burlina and C Schatz and S Sagan and G Chassaing and D Braguer and S Lavielle}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84900758830&doi=10.1016%2fj.bbamem.2014.04.025&partnerID=40&md5=27a2b3bbbc1de45ec0193a3cfc9b7fb7}, doi = {10.1016/j.bbamem.2014.04.025}, year = {2014}, date = {2014-01-01}, journal = {Biochimica et Biophysica Acta - Biomembranes}, volume = {1838}, number = {8}, pages = {2087--2098}, abstract = {The peptide KLA (acetyl-(KLAKLAK)2-NH2), which is rather non toxic for eukaryotic cell lines, becomes active when coupled to the cell penetrating peptide, penetratin (Pen), by a disulfide bridge. Remarkably, the conjugate KLA-Pen is cytotoxic, at low micromolar concentrations, against a panel of seven human tumor cell lines of various tissue origins, including cells resistant to conventional chemotherapy agents but not to normal human cell lines. Live microscopy on cells possessing fluorescent labeled mitochondria shows that in tumor cells, KLA-Pen had a strong impact on mitochondria tubular organization instantly resulting in their aggregation, while the unconjugated KLA and pen peptides had no effect. But, mitochondria in various normal cells were not affected by KLA-Pen. The interaction with membrane models of KLA-Pen, KLA and penetratin were studied using dynamic light scattering, calorimetry, plasmon resonance, circular dichroism and ATR-FTIR to unveil the mode of action of the conjugate. To understand the selectivity of the conjugate towards tumor cell lines and its action on mitochondria, lipid model systems composed of zwitterionic lipids were used as mimics of normal cell membranes and anionic lipids as mimics of tumor cell and mitochondria membrane. A very distinct mode of interaction with the two model systems was observed. KLA-Pen may exert its deleterious and selective action on cancer cells by the formation of pores with an oblique membrane orientation and establishment of important hydrophobic interactions. These results suggest that KLA-Pen could be a lead compound for the design of cancer therapeutics. © 2014 Elsevier B.V.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The peptide KLA (acetyl-(KLAKLAK)2-NH2), which is rather non toxic for eukaryotic cell lines, becomes active when coupled to the cell penetrating peptide, penetratin (Pen), by a disulfide bridge. Remarkably, the conjugate KLA-Pen is cytotoxic, at low micromolar concentrations, against a panel of seven human tumor cell lines of various tissue origins, including cells resistant to conventional chemotherapy agents but not to normal human cell lines. Live microscopy on cells possessing fluorescent labeled mitochondria shows that in tumor cells, KLA-Pen had a strong impact on mitochondria tubular organization instantly resulting in their aggregation, while the unconjugated KLA and pen peptides had no effect. But, mitochondria in various normal cells were not affected by KLA-Pen. The interaction with membrane models of KLA-Pen, KLA and penetratin were studied using dynamic light scattering, calorimetry, plasmon resonance, circular dichroism and ATR-FTIR to unveil the mode of action of the conjugate. To understand the selectivity of the conjugate towards tumor cell lines and its action on mitochondria, lipid model systems composed of zwitterionic lipids were used as mimics of normal cell membranes and anionic lipids as mimics of tumor cell and mitochondria membrane. A very distinct mode of interaction with the two model systems was observed. KLA-Pen may exert its deleterious and selective action on cancer cells by the formation of pores with an oblique membrane orientation and establishment of important hydrophobic interactions. These results suggest that KLA-Pen could be a lead compound for the design of cancer therapeutics. © 2014 Elsevier B.V. |
The Efficacies of cell-penetrating peptides in accumulating in large unilamellar vesicles depend on their ability to form inverted micelles Article de journal J -M Swiecicki; A Bartsch; J Tailhades; M Di Pisa; B Heller; G Chassaing; C Mansuy; F Burlina; S Lavielle ChemBioChem, 15 (6), p. 884–891, 2014. @article{Swiecicki:2014, title = {The Efficacies of cell-penetrating peptides in accumulating in large unilamellar vesicles depend on their ability to form inverted micelles}, author = {J -M Swiecicki and A Bartsch and J Tailhades and M Di Pisa and B Heller and G Chassaing and C Mansuy and F Burlina and S Lavielle}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84898543428&doi=10.1002%2fcbic.201300742&partnerID=40&md5=8311e7ff65490dd62302ee8d8cb54e86}, doi = {10.1002/cbic.201300742}, year = {2014}, date = {2014-01-01}, journal = {ChemBioChem}, volume = {15}, number = {6}, pages = {884--891}, abstract = {In this study, the direct translocation of cell-penetrating peptides (CPPs) into large unilamellar vesicles (LUVs) was shown to be rapid for all the most commonly used CPPs. This translocation led within a few minutes to intravesicular accumulation up to 0.5 mM, with no need for a transbilayer potential. The accumulation of CPPs inside LUVs was found to depend on CPP sequence, CPP extravesicular concentration and phospholipid (PL) composition, either in binary or ternary mixtures of PLs. More interestingly, the role of anionic phospholipid flip-flopping in the translocation process was ascertained. CPPs enhanced the flipping of PLs, and the intravesicular CPP accumulation directly correlated with the amount of anionic PLs that had been transferred from the external to the internal leaflet of the LUV bilayer, thus demonstrating the transport of peptide/lipid complexes as inverted micelles. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.}, keywords = {}, pubstate = {published}, tppubtype = {article} } In this study, the direct translocation of cell-penetrating peptides (CPPs) into large unilamellar vesicles (LUVs) was shown to be rapid for all the most commonly used CPPs. This translocation led within a few minutes to intravesicular accumulation up to 0.5 mM, with no need for a transbilayer potential. The accumulation of CPPs inside LUVs was found to depend on CPP sequence, CPP extravesicular concentration and phospholipid (PL) composition, either in binary or ternary mixtures of PLs. More interestingly, the role of anionic phospholipid flip-flopping in the translocation process was ascertained. CPPs enhanced the flipping of PLs, and the intravesicular CPP accumulation directly correlated with the amount of anionic PLs that had been transferred from the external to the internal leaflet of the LUV bilayer, thus demonstrating the transport of peptide/lipid complexes as inverted micelles. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. |
Glaser oxidative coupling on peptides: Stabilization of β-turn structure via a 1,3-butadiyne constraint Article de journal N Auberger; M D Pisa; M Larregola; G Chassaing; E Peroni; S Lavielle; A -M Papini; O Lequin; J -M Mallet Bioorganic and Medicinal Chemistry, 22 (24), p. 6924–6932, 2014. @article{Auberger:2014, title = {Glaser oxidative coupling on peptides: Stabilization of β-turn structure via a 1,3-butadiyne constraint}, author = {N Auberger and M D Pisa and M Larregola and G Chassaing and E Peroni and S Lavielle and A -M Papini and O Lequin and J -M Mallet}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84913568783&doi=10.1016%2fj.bmc.2014.10.026&partnerID=40&md5=39fa745c71be69e3531b73a75a19afac}, doi = {10.1016/j.bmc.2014.10.026}, year = {2014}, date = {2014-01-01}, journal = {Bioorganic and Medicinal Chemistry}, volume = {22}, number = {24}, pages = {6924--6932}, abstract = {The Glaser-Eglinton reaction between either two C or N propargylglycine (Pra or NPra) amino acids, in the presence of copper(II), led to cyclic hexa- and octapeptides constrained by a butadiyne bridge. The on-resin cyclization conditions were analyzed and optimized. The consequences of this type of constraint on the three dimensional structure of these hexapeptides and octapeptides were analyzed in details by NMR and molecular dynamics. We show that stabilized short cyclic peptides could be readily prepared via the Glaser oxidative coupling either with a chiral (Pra), or achiral (NPra) residue. The 1,3-butadiyne cyclization, along with disulfide bridged and lactam cyclized hexapeptides expands the range of constrained peptides that will allow exploring the breathing of amino acids around a β-turn structure. © 2014 Elsevier Ltd. All rights reserved.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The Glaser-Eglinton reaction between either two C or N propargylglycine (Pra or NPra) amino acids, in the presence of copper(II), led to cyclic hexa- and octapeptides constrained by a butadiyne bridge. The on-resin cyclization conditions were analyzed and optimized. The consequences of this type of constraint on the three dimensional structure of these hexapeptides and octapeptides were analyzed in details by NMR and molecular dynamics. We show that stabilized short cyclic peptides could be readily prepared via the Glaser oxidative coupling either with a chiral (Pra), or achiral (NPra) residue. The 1,3-butadiyne cyclization, along with disulfide bridged and lactam cyclized hexapeptides expands the range of constrained peptides that will allow exploring the breathing of amino acids around a β-turn structure. © 2014 Elsevier Ltd. All rights reserved. |
G Leclercq; Y Jacquot Journal of Steroid Biochemistry and Molecular Biology, 139 , p. 237–244, 2014. @article{Leclercq:2014, title = {Interactions of isoflavones and other plant derived estrogens with estrogen receptors for prevention and treatment of breast cancer - Considerations concerning related efficacy and safety}, author = {G Leclercq and Y Jacquot}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84889881769&doi=10.1016%2fj.jsbmb.2012.12.010&partnerID=40&md5=2e2302b29629a108259fb35e7ec5da20}, doi = {10.1016/j.jsbmb.2012.12.010}, year = {2014}, date = {2014-01-01}, journal = {Journal of Steroid Biochemistry and Molecular Biology}, volume = {139}, pages = {237--244}, abstract = {Phytoestrogens are natural endocrine disruptors that interfere with estrogenic pathways. They insert directly within the hormone-binding domain of ERα and β, with a preference for the β isoform of which the concentration predominates in the normal mammary epithelium. Since ERβ antagonizes the growth promoting effect of ERα, which is mainly expressed in estrogen-sensitive tumor cells, a potential protective action against breast cancer incidence has been ascribed to phytoestrogens. The fact that Asian women living in far-east countries who consume isoflavone-rich food are less subjected to breast cancer emergence than their congeners in the USA as well as Caucasian women has been advocated to justify such a concept. Overview of data concerning the mechanism of action phytoestrogens reveals that such a view is an oversimplification: Such compounds interfere with a huge panel of regulatory proteins, giving rise to both promoting and antagonizing carcinogenic effects. Moreover, various physiological and pathological factors able to amplify these effects are not often sufficiently taken into account, which increases the difficulty to interpret data. Nevertheless, this overview of data established that chemical structures and concentrations modulate such effects: at the micromolar level, isoflavones activate ERα-mediated transcription and breast cancer cell proliferation while flavones fail to induce any significant promoting effects. At higher doses, both classes of compounds may display an antitumor activity. Reasons for such distinct behaviors as well as their potential impact in therapeutic applications are analyzed here. Ability of isoflavones and flavones to antagonize the association of calmodulin to ERα, which is required for its enhanced transcriptional activity is evoked to justify the antitumor activity ascribed to some flavones. Finally, a suspicion that peculiar classes of phytoestrogens may adopt a SERM-like conformation is addressed in a context of selection and synthesis of compounds with non-equivocal therapeutic value. This article is part of a Special Issue entitled "Phytoestrogens". © 2012 Elsevier Ltd.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Phytoestrogens are natural endocrine disruptors that interfere with estrogenic pathways. They insert directly within the hormone-binding domain of ERα and β, with a preference for the β isoform of which the concentration predominates in the normal mammary epithelium. Since ERβ antagonizes the growth promoting effect of ERα, which is mainly expressed in estrogen-sensitive tumor cells, a potential protective action against breast cancer incidence has been ascribed to phytoestrogens. The fact that Asian women living in far-east countries who consume isoflavone-rich food are less subjected to breast cancer emergence than their congeners in the USA as well as Caucasian women has been advocated to justify such a concept. Overview of data concerning the mechanism of action phytoestrogens reveals that such a view is an oversimplification: Such compounds interfere with a huge panel of regulatory proteins, giving rise to both promoting and antagonizing carcinogenic effects. Moreover, various physiological and pathological factors able to amplify these effects are not often sufficiently taken into account, which increases the difficulty to interpret data. Nevertheless, this overview of data established that chemical structures and concentrations modulate such effects: at the micromolar level, isoflavones activate ERα-mediated transcription and breast cancer cell proliferation while flavones fail to induce any significant promoting effects. At higher doses, both classes of compounds may display an antitumor activity. Reasons for such distinct behaviors as well as their potential impact in therapeutic applications are analyzed here. Ability of isoflavones and flavones to antagonize the association of calmodulin to ERα, which is required for its enhanced transcriptional activity is evoked to justify the antitumor activity ascribed to some flavones. Finally, a suspicion that peculiar classes of phytoestrogens may adopt a SERM-like conformation is addressed in a context of selection and synthesis of compounds with non-equivocal therapeutic value. This article is part of a Special Issue entitled "Phytoestrogens". © 2012 Elsevier Ltd. |
Delivery of antisense peptide nucleic acids to cells by conjugation with small arginine-rich cell-penetrating peptide (R/W)9 Article de journal C Cordier; F Boutimah; M Bourdeloux; F Dupuy; E Met; P Alberti; F Loll; G Chassaing; F Burlina; T E Saison-Behmoaras PLoS ONE, 9 (8), 2014. @article{Cordier:2014, title = {Delivery of antisense peptide nucleic acids to cells by conjugation with small arginine-rich cell-penetrating peptide (R/W)9}, author = {C Cordier and F Boutimah and M Bourdeloux and F Dupuy and E Met and P Alberti and F Loll and G Chassaing and F Burlina and T E Saison-Behmoaras}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84937874688&doi=10.1371%2fjournal.pone.0104999&partnerID=40&md5=a4a8c920f008f09c530535fbd70afa09}, doi = {10.1371/journal.pone.0104999}, year = {2014}, date = {2014-01-01}, journal = {PLoS ONE}, volume = {9}, number = {8}, abstract = {Peptide nucleic acids (PNAs) are very attractive antisense and antigene agents, but these molecules are not passively taken into cells. Here, using a functional cell assay and fluorescent-based methods, we investigated cell uptake and antisense activity of a tridecamer PNA that targets the HIV-1 polypurine tract sequence delivered using the arginine-rich (R/W)9 peptide (RRWWRRWRR). At micromolar concentrations, without use of any transfection agents, almost 80% inhibition of the target gene expression was obtained with the conjugate in the presence of the endosomolytic agent chloroquine. We show that chloroquine not only induced escape from endosomes but also enhanced the cellular uptake of the conjugate. Mechanistic studies revealed that (R/W)9-PNA conjugates were internalized via pinocytosis. Replacement of arginines with lysines reduced the uptake of the conjugate by six-fold, resulting in the abolition of intracellular target inhibition. Our results show that the arginines play a crucial role in the conjugate uptake and antisense activity. To determine whether specificity of the interactions of arginines with cell surface proteoglycans result in the internalization, we used flow cytometry to examine uptake of arginine- and lysine-rich conjugates in wild-type CHO-K1 and proteoglycan-deficient A745 cells. The uptake of both conjugates was decreased by four fold in CHO-745 cells; therefore proteoglycans promote internalization of cationic peptides, irrespective of the chemical nature of their positive charges. Our results show that arginine-rich cell-penetrating peptides, especially (R/W)9, are a promising tool for PNA internalization. © 2014 Cordier et al.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Peptide nucleic acids (PNAs) are very attractive antisense and antigene agents, but these molecules are not passively taken into cells. Here, using a functional cell assay and fluorescent-based methods, we investigated cell uptake and antisense activity of a tridecamer PNA that targets the HIV-1 polypurine tract sequence delivered using the arginine-rich (R/W)9 peptide (RRWWRRWRR). At micromolar concentrations, without use of any transfection agents, almost 80% inhibition of the target gene expression was obtained with the conjugate in the presence of the endosomolytic agent chloroquine. We show that chloroquine not only induced escape from endosomes but also enhanced the cellular uptake of the conjugate. Mechanistic studies revealed that (R/W)9-PNA conjugates were internalized via pinocytosis. Replacement of arginines with lysines reduced the uptake of the conjugate by six-fold, resulting in the abolition of intracellular target inhibition. Our results show that the arginines play a crucial role in the conjugate uptake and antisense activity. To determine whether specificity of the interactions of arginines with cell surface proteoglycans result in the internalization, we used flow cytometry to examine uptake of arginine- and lysine-rich conjugates in wild-type CHO-K1 and proteoglycan-deficient A745 cells. The uptake of both conjugates was decreased by four fold in CHO-745 cells; therefore proteoglycans promote internalization of cationic peptides, irrespective of the chemical nature of their positive charges. Our results show that arginine-rich cell-penetrating peptides, especially (R/W)9, are a promising tool for PNA internalization. © 2014 Cordier et al. |
Influence of the side-chain length on the cellular uptake and the cytotoxicity of rhenium triscarbonyl derivatives: A bimodal infrared and luminescence quantitative study Article de journal S Clède; F Lambert; R Saint-Fort; M -A Plamont; H Bertrand; A Vessières; C Policar Chemistry - A European Journal, 20 (28), p. 8714–8722, 2014. @article{Clede:2014, title = {Influence of the side-chain length on the cellular uptake and the cytotoxicity of rhenium triscarbonyl derivatives: A bimodal infrared and luminescence quantitative study}, author = {S Cl\`{e}de and F Lambert and R Saint-Fort and M -A Plamont and H Bertrand and A Vessi\`{e}res and C Policar}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84903724808&doi=10.1002%2fchem.201402471&partnerID=40&md5=7334edd420d748a4418df936173a79b9}, doi = {10.1002/chem.201402471}, year = {2014}, date = {2014-01-01}, journal = {Chemistry - A European Journal}, volume = {20}, number = {28}, pages = {8714--8722}, abstract = {Rhenium triscarbonyl complexes fac-[Re(CO)3(NtextasciicircumN)] with appropriate ancillary NtextasciicircumN ligands are relevant for fluorescent bio-imaging. Recently, we have shown that [Re(CO)3] cores can also be efficiently mapped inside cells using their IR signature and that they can thus be used in a bimodal approach. To describe them we have coined the term SCoMPIs for single-core multimodal probes for imaging. In the context of the use of these SCoMPIs in bio-imaging, the questions of their cellular uptake and cytotoxicity are critical. We report here a series of compounds derived from the [Re(CO) 3Cl(pyta)] core (pyta=4-(2-pyridyl)-1,2,3-triazole). The pyta ligand is of interest because it can be easily functionalized. Aliphatic side chains (C4, C8, and C12) were appended to this core. A correlative study involving IR and luminescence was performed to monitor and quantify their cellular internalization. We studied the relationship between lipophilicity (log P(o/w)), cytotoxicity (IC50), and cellular uptake, and we showed that both uptake and cytotoxicity increase with the length of the side chain, with a higher uptake for the C12 derivative. This study stresses the distinction that has to be made between apparent toxicity, determined as an incubation concentration IC50, and intrinsic toxicity. Indeed, the intrinsic toxicity of a compound can remain hidden if it is not cell permeable. Therefore it must be kept in mind that IC50 values are composite values, reflecting both cellular uptake and intrinsic toxicity. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Rhenium triscarbonyl complexes fac-[Re(CO)3(NtextasciicircumN)] with appropriate ancillary NtextasciicircumN ligands are relevant for fluorescent bio-imaging. Recently, we have shown that [Re(CO)3] cores can also be efficiently mapped inside cells using their IR signature and that they can thus be used in a bimodal approach. To describe them we have coined the term SCoMPIs for single-core multimodal probes for imaging. In the context of the use of these SCoMPIs in bio-imaging, the questions of their cellular uptake and cytotoxicity are critical. We report here a series of compounds derived from the [Re(CO) 3Cl(pyta)] core (pyta=4-(2-pyridyl)-1,2,3-triazole). The pyta ligand is of interest because it can be easily functionalized. Aliphatic side chains (C4, C8, and C12) were appended to this core. A correlative study involving IR and luminescence was performed to monitor and quantify their cellular internalization. We studied the relationship between lipophilicity (log P(o/w)), cytotoxicity (IC50), and cellular uptake, and we showed that both uptake and cytotoxicity increase with the length of the side chain, with a higher uptake for the C12 derivative. This study stresses the distinction that has to be made between apparent toxicity, determined as an incubation concentration IC50, and intrinsic toxicity. Indeed, the intrinsic toxicity of a compound can remain hidden if it is not cell permeable. Therefore it must be kept in mind that IC50 values are composite values, reflecting both cellular uptake and intrinsic toxicity. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. |
Electrochemical formation and reactivity of a manganese peroxo complex: Acid driven Ħ2O2 generation vs. O-O bond cleavage Article de journal H Y V Ching; E Anxolabéhère-Mallart; H E Colmer; C Costentin; P Dorlet; T A Jackson; C Policar; M Robert Chemical Science, 5 (6), p. 2304–2310, 2014. @article{Ching:2014, title = {Electrochemical formation and reactivity of a manganese peroxo complex: Acid driven {H}2O2 generation vs. O-O bond cleavage}, author = {H Y V Ching and E Anxolab\'{e}h\`{e}re-Mallart and H E Colmer and C Costentin and P Dorlet and T A Jackson and C Policar and M Robert}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84900329910&doi=10.1039%2fc3sc53469c&partnerID=40&md5=8b4ecc598d6455d82b1681e608484bc1}, doi = {10.1039/c3sc53469c}, year = {2014}, date = {2014-01-01}, journal = {Chemical Science}, volume = {5}, number = {6}, pages = {2304--2310}, abstract = {The formation of a side-on peroxo [MnIIIL(O2)] complex (L = phenolato-containing pentadentate ligand), resulting from the reaction of electrochemically reduced O2 and [MnIIL] +, is monitored in DMF using cyclic voltammetry, low temperature electronic absorption spectroscopy and electron paramagnetic resonance spectroscopy. Mechanistic studies based on cyclic voltammetry reveal that upon addition of a strong acid the Mn-O bond is broken, resulting in the release of H2O2, whereas in the presence of a weak acid the O-O bond is cleaved via a concerted dissociative electron transfer. This dichotomy of M-O versus O-O bond cleavage is unprecedented for peroxomanganese(iii) complexes and the latter offers a route for electrochemical O2 activation by a manganese(ii) complex. This journal is © the Partner Organisations 2014.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The formation of a side-on peroxo [MnIIIL(O2)] complex (L = phenolato-containing pentadentate ligand), resulting from the reaction of electrochemically reduced O2 and [MnIIL] +, is monitored in DMF using cyclic voltammetry, low temperature electronic absorption spectroscopy and electron paramagnetic resonance spectroscopy. Mechanistic studies based on cyclic voltammetry reveal that upon addition of a strong acid the Mn-O bond is broken, resulting in the release of H2O2, whereas in the presence of a weak acid the O-O bond is cleaved via a concerted dissociative electron transfer. This dichotomy of M-O versus O-O bond cleavage is unprecedented for peroxomanganese(iii) complexes and the latter offers a route for electrochemical O2 activation by a manganese(ii) complex. This journal is © the Partner Organisations 2014. |
Conjugation of a new series of dithiocarbazate schiff base copper(II) complexes with vectors selected to enhance antibacterial activity Article de journal M L Low; L Maigre; P Dorlet; R Guillot; J -M Pagès; K A Crouse; C Policar; N Delsuc Bioconjugate Chemistry, 25 (12), p. 2269–2284, 2014. @article{Low:2014, title = {Conjugation of a new series of dithiocarbazate schiff base copper(II) complexes with vectors selected to enhance antibacterial activity}, author = {M L Low and L Maigre and P Dorlet and R Guillot and J -M Pag\`{e}s and K A Crouse and C Policar and N Delsuc}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84918505283&doi=10.1021%2fbc5004907&partnerID=40&md5=d51ad81235fa7fd9aec14b7acd2c908a}, doi = {10.1021/bc5004907}, year = {2014}, date = {2014-01-01}, journal = {Bioconjugate Chemistry}, volume = {25}, number = {12}, pages = {2269--2284}, abstract = {A new series of six Schiff bases derived from S-methyldithiocarbazate (SMDTC) and S-benzyldithiocarbazate (SBDTC) with methyl levulinate (SMML, SBML), levulinic acid (SMLA, SBLA), and 4-carboxybenzaldehyde (SM4CB, SB4CB) were reacted with copper(II), producing complexes of general formula MLtextlessinftextgreater2textless/inftextgreater (M = Cu(II)}, keywords = {}, pubstate = {published}, tppubtype = {article} } A new series of six Schiff bases derived from S-methyldithiocarbazate (SMDTC) and S-benzyldithiocarbazate (SBDTC) with methyl levulinate (SMML, SBML), levulinic acid (SMLA, SBLA), and 4-carboxybenzaldehyde (SM4CB, SB4CB) were reacted with copper(II), producing complexes of general formula MLtextlessinftextgreater2textless/inftextgreater (M = Cu(II) |
Apo-neocarzinostatin: A protein carrier for Cu(II) glycocomplexes and Cu(II) into U937 and HT29 cell lines Article de journal L Garcia; S Franzoni; F Mussi; M Aumont-Niçaise; H Bertrand; M Desmadril; G Pelosi; A Buschini; C Policar Journal of Inorganic Biochemistry, 135 , p. 40–44, 2014. @article{Garcia:2014, title = {Apo-neocarzinostatin: A protein carrier for Cu(II) glycocomplexes and Cu(II) into U937 and HT29 cell lines}, author = {L Garcia and S Franzoni and F Mussi and M Aumont-Ni\c{c}aise and H Bertrand and M Desmadril and G Pelosi and A Buschini and C Policar}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84896943429&doi=10.1016%2fj.jinorgbio.2014.02.006&partnerID=40&md5=81ab9f0bb44feb00966cfb5735d8901a}, doi = {10.1016/j.jinorgbio.2014.02.006}, year = {2014}, date = {2014-01-01}, journal = {Journal of Inorganic Biochemistry}, volume = {135}, pages = {40--44}, abstract = {In the field of pharmaceuticals there is an increasing need for new delivery systems to overcome the issues of solubility, penetration, toxicity and drug resistance. One of the possible strategies is to use biocarriers such as proteins to encourage the cell-penetration of drugs. In this paper, the use of the apo-protein neocarzinostatin (apo-NCS) as a carrier-protein for two Cu(II) glycocomplexes, previously characterized, and Cu(II) ions was investigated. Its interaction with the metallic compounds was analyzed using microcalorimetry. The dissociation constants were shown to be in the micromolar range. The Cu(II) glycocomplexes, in absence of apo-NCS, were found to be cytotoxic in the U937 and HT29 cell lines whereas the corresponding glycoligands showed no toxicity. The leukemic cell line (U937) seems to be more sensitive to glycocomplexes than the colon cancer cell line (HT29). Interestingly, apo-NCS was shown to increase systematically the antiproliferative activity by a factor of 2 and 3 for Cu(II) glycocomplexes and Cu(II) respectively. The antiproliferative activity detected was not related to proteasome inhibition. This result stresses the importance of new molecular tools for the delivery of Cu(II) to tumor cells using non-covalent association with carriers proteins. © 2014 Elsevier Inc. All rights reserved.}, keywords = {}, pubstate = {published}, tppubtype = {article} } In the field of pharmaceuticals there is an increasing need for new delivery systems to overcome the issues of solubility, penetration, toxicity and drug resistance. One of the possible strategies is to use biocarriers such as proteins to encourage the cell-penetration of drugs. In this paper, the use of the apo-protein neocarzinostatin (apo-NCS) as a carrier-protein for two Cu(II) glycocomplexes, previously characterized, and Cu(II) ions was investigated. Its interaction with the metallic compounds was analyzed using microcalorimetry. The dissociation constants were shown to be in the micromolar range. The Cu(II) glycocomplexes, in absence of apo-NCS, were found to be cytotoxic in the U937 and HT29 cell lines whereas the corresponding glycoligands showed no toxicity. The leukemic cell line (U937) seems to be more sensitive to glycocomplexes than the colon cancer cell line (HT29). Interestingly, apo-NCS was shown to increase systematically the antiproliferative activity by a factor of 2 and 3 for Cu(II) glycocomplexes and Cu(II) respectively. The antiproliferative activity detected was not related to proteasome inhibition. This result stresses the importance of new molecular tools for the delivery of Cu(II) to tumor cells using non-covalent association with carriers proteins. © 2014 Elsevier Inc. All rights reserved. |
Luminescence modulations of rhenium tricarbonyl complexes induced by structural variations Article de journal H C Bertrand; S Clède; R Guillot; F Lambert; C Policar Inorganic Chemistry, 53 (12), p. 6204–6223, 2014. @article{Bertrand:2014, title = {Luminescence modulations of rhenium tricarbonyl complexes induced by structural variations}, author = {H C Bertrand and S Cl\`{e}de and R Guillot and F Lambert and C Policar}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84902530649&doi=10.1021%2fic5007007&partnerID=40&md5=f3030a715ad7c095b013503a9d5b44a8}, doi = {10.1021/ic5007007}, year = {2014}, date = {2014-01-01}, journal = {Inorganic Chemistry}, volume = {53}, number = {12}, pages = {6204--6223}, abstract = {Octahedral d6 low-spin Re(I) tricarbonyl complexes are of considerable interest as noninvasive imaging probes and have been deeply studied owing to their biological stability, low toxicity, large Stokes shifts, and long luminescence lifetimes. We reported recently the bimodal IR and luminescence imaging of a Re(I) tricarbonyl complex with a Pyta ligand (4-(2-pyridyl)-1,2,3-triazole) in cells and labeled such metal-carbonyl complexes SCoMPIs for single-core multimodal probes for imaging. Re(I) tricarbonyl complexes have unique photophysical properties allowing for their unequivocal detection in cells but also present some weaknesses such as a very low luminescence quantum yield in aqueous medium. Further optimizations would thus be desirable. We therefore developed new Re(I) tricarbonyl complexes prepared from different ancillary ligands. Complexes with benzothiadiazole- triazole ligands show interesting luminescent quantum yields in acetonitrile and may constitute valuable luminescent metal complexes in organic media. A series of complexes with bidentate 1-(2-quinolinyl)-1,2,3-triazole (Taquin) and 1-(2-pyridyl)-1,2,3-triazole (Tapy) ligands bearing various 4-substituted alkyl side chains has been designed and synthesized with efficient procedures. Their photophysical properties have been characterized in acetonitrile and in a H 2O/DMSO (98/2) mixture and compared with those of the parent Quinta- and Pyta-based complexes. Tapy complexes bearing long alkyl chains show impressive enhancement of their luminescent properties relative to the parent Pyta complex. Theoretical calculations have been performed to further characterize this new class of rhenium tricarbonyl complexes. Preliminary cellular imaging studies in MDA-MB231 breast cancer cells reveal a strong increase in the luminescence signal in cells incubated with the Tapy complex substituted with a C12 alkyl chain. This study points out the interesting potential of the Tapy ligand in coordination chemistry, which has been so far underexploited. © 2014 American Chemical Society.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Octahedral d6 low-spin Re(I) tricarbonyl complexes are of considerable interest as noninvasive imaging probes and have been deeply studied owing to their biological stability, low toxicity, large Stokes shifts, and long luminescence lifetimes. We reported recently the bimodal IR and luminescence imaging of a Re(I) tricarbonyl complex with a Pyta ligand (4-(2-pyridyl)-1,2,3-triazole) in cells and labeled such metal-carbonyl complexes SCoMPIs for single-core multimodal probes for imaging. Re(I) tricarbonyl complexes have unique photophysical properties allowing for their unequivocal detection in cells but also present some weaknesses such as a very low luminescence quantum yield in aqueous medium. Further optimizations would thus be desirable. We therefore developed new Re(I) tricarbonyl complexes prepared from different ancillary ligands. Complexes with benzothiadiazole- triazole ligands show interesting luminescent quantum yields in acetonitrile and may constitute valuable luminescent metal complexes in organic media. A series of complexes with bidentate 1-(2-quinolinyl)-1,2,3-triazole (Taquin) and 1-(2-pyridyl)-1,2,3-triazole (Tapy) ligands bearing various 4-substituted alkyl side chains has been designed and synthesized with efficient procedures. Their photophysical properties have been characterized in acetonitrile and in a H 2O/DMSO (98/2) mixture and compared with those of the parent Quinta- and Pyta-based complexes. Tapy complexes bearing long alkyl chains show impressive enhancement of their luminescent properties relative to the parent Pyta complex. Theoretical calculations have been performed to further characterize this new class of rhenium tricarbonyl complexes. Preliminary cellular imaging studies in MDA-MB231 breast cancer cells reveal a strong increase in the luminescence signal in cells incubated with the Tapy complex substituted with a C12 alkyl chain. This study points out the interesting potential of the Tapy ligand in coordination chemistry, which has been so far underexploited. © 2014 American Chemical Society. |
Fourier transform infrared (FT-IR) spectromicroscopy to identify cell organelles: Correlation with fluorescence staining in MCF-7 breast cancer cells Article de journal S Clède; C Policar; C Sandt Applied Spectroscopy, 68 (1), p. 113–117, 2014. @article{Clede:2014a, title = {Fourier transform infrared (FT-IR) spectromicroscopy to identify cell organelles: Correlation with fluorescence staining in MCF-7 breast cancer cells}, author = {S Cl\`{e}de and C Policar and C Sandt}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84893060662&doi=10.1366%2f13-07139&partnerID=40&md5=f492b0918395dff47f71071460ac1f20}, doi = {10.1366/13-07139}, year = {2014}, date = {2014-01-01}, journal = {Applied Spectroscopy}, volume = {68}, number = {1}, pages = {113--117}, abstract = {Biomolecules display specific vibrational signatures in the infrared (IR) range, and organelles that concentrate these biomolecules can be identified by these IR signatures. Subcellular identification and location of cell organelles using IR signatures is attractive as it does not require the use of any specific trackers and is thus noninvasive and non-destructive. We show here that endogenous IR absorptions are relevant to detecting and imaging the nucleus, the cytoplasm, and the Golgi apparatus/endoplasmic reticulum in MCF- 7 breast cancer cells, and we compare these results with our previous work on the HeLa cell line. We correlate maps of fixed and dried cells obtained by synchrotron radiation Fourier transform infrared (SR FT-IR) spectromicroscopy with epifluorescence images using fluorescent trackers for Golgi apparatus and nucleus, namely BODIPY TR C5-ceramide complexed to BSA and DAPI, respectively. Interestingly, the ratios of the IR bands CH2:CH 3 (both asymmetric and symmetric) and CO(ester):amide I were shown to be reliable gauges of the lipidic character of a cellular compartment, the -CH2 and the CO(ester) absorptions increasing with the presence of inner membranes like in the Golgi apparatus. © 2014 Society for Applied Spectroscopy.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Biomolecules display specific vibrational signatures in the infrared (IR) range, and organelles that concentrate these biomolecules can be identified by these IR signatures. Subcellular identification and location of cell organelles using IR signatures is attractive as it does not require the use of any specific trackers and is thus noninvasive and non-destructive. We show here that endogenous IR absorptions are relevant to detecting and imaging the nucleus, the cytoplasm, and the Golgi apparatus/endoplasmic reticulum in MCF- 7 breast cancer cells, and we compare these results with our previous work on the HeLa cell line. We correlate maps of fixed and dried cells obtained by synchrotron radiation Fourier transform infrared (SR FT-IR) spectromicroscopy with epifluorescence images using fluorescent trackers for Golgi apparatus and nucleus, namely BODIPY TR C5-ceramide complexed to BSA and DAPI, respectively. Interestingly, the ratios of the IR bands CH2:CH 3 (both asymmetric and symmetric) and CO(ester):amide I were shown to be reliable gauges of the lipidic character of a cellular compartment, the -CH2 and the CO(ester) absorptions increasing with the presence of inner membranes like in the Golgi apparatus. © 2014 Society for Applied Spectroscopy. |
From IR-Spectromicroscopy using AFM-IR and SR-FTIR to Bimodal Spectromicroscopy using SCoMPIs - Single Core Multimodal Probe for Imaging Article de journal C Policar; C Sylvain; F Lambert; N Delsuc; C Sandt; P Dumas; M Refregiers; M Plamont; A Vessieres; Z Gueroui; A Dazzi Journal of Biological Inorganic Chemistry, 19 , p. S182-S182, 2014, ISSN: 0949-8257. @article{RN23c, title = {From IR-Spectromicroscopy using AFM-IR and SR-FTIR to Bimodal Spectromicroscopy using SCoMPIs - Single Core Multimodal Probe for Imaging}, author = {C Policar and C Sylvain and F Lambert and N Delsuc and C Sandt and P Dumas and M Refregiers and M Plamont and A Vessieres and Z Gueroui and A Dazzi}, url = {<Go to ISI>://WOS:000332835300124}, issn = {0949-8257}, year = {2014}, date = {2014-01-01}, journal = {Journal of Biological Inorganic Chemistry}, volume = {19}, pages = {S182-S182}, keywords = {}, pubstate = {published}, tppubtype = {article} } |
Characterization of the recombinant Candida albicans β-1,2- mannosyltransferase that initiates the β-mannosylation of cell wall phosphopeptidomannan Article de journal E Fabre; G Sfihi-Loualia; M Pourcelot; B Coddeville; F Krzewinski; J Bouckaert; E Maes; T Hurtaux; R Dubois; C Fradin; J -M Mallet; D Poulain; F Delplace; Y Guerardel Biochemical Journal, 457 (2), p. 347–360, 2014. @article{Fabre:2014, title = {Characterization of the recombinant Candida albicans β-1,2- mannosyltransferase that initiates the β-mannosylation of cell wall phosphopeptidomannan}, author = {E Fabre and G Sfihi-Loualia and M Pourcelot and B Coddeville and F Krzewinski and J Bouckaert and E Maes and T Hurtaux and R Dubois and C Fradin and J -M Mallet and D Poulain and F Delplace and Y Guerardel}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84890933063&doi=10.1042%2fBJ20131012&partnerID=40&md5=d949ce34b6392323fca30b0ee92dbea5}, doi = {10.1042/BJ20131012}, year = {2014}, date = {2014-01-01}, journal = {Biochemical Journal}, volume = {457}, number = {2}, pages = {347--360}, abstract = {The presence of β-mannosides in their cell walls confers specific features on the pathogenic yeasts Candida albicans and Candida glabrata compared with non-pathogenic yeasts. In the present study, we investigated the enzymatic properties of Bmt1 (β-mannosyltransferase 1), a member of the recently identified β-mannosyltransferase family, from C. albicans. A recombinant soluble enzyme lacking the N-terminal region was expressed as a secreted protein from the methylotrophic yeast Pichia pastoris. In parallel, functionalized natural oligosaccharides isolated from Saccharomyces cerevisiae and a C. albicans mutant strain, as well as synthetic α-oligomannosides, were prepared and used as potential acceptor substrates. Bmt1p preferentially utilizes substrates containing linear chains of α-1,2-linked mannotriose or mannotetraose. The recombinant enzyme consecutively transfers two mannosyl units on to these acceptors, leading to the production of α-mannosidase- resistant oligomannosides. NMR experiments further confirmed the presence of a terminal βMan (β-1,2-linked mannose) unit in the first enzyme product. In the future, a better understanding of specific β-1,2- mannosyltransferase molecular requirements will help the design of new potential antifungal drugs. © 2014 Biochemical Society.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The presence of β-mannosides in their cell walls confers specific features on the pathogenic yeasts Candida albicans and Candida glabrata compared with non-pathogenic yeasts. In the present study, we investigated the enzymatic properties of Bmt1 (β-mannosyltransferase 1), a member of the recently identified β-mannosyltransferase family, from C. albicans. A recombinant soluble enzyme lacking the N-terminal region was expressed as a secreted protein from the methylotrophic yeast Pichia pastoris. In parallel, functionalized natural oligosaccharides isolated from Saccharomyces cerevisiae and a C. albicans mutant strain, as well as synthetic α-oligomannosides, were prepared and used as potential acceptor substrates. Bmt1p preferentially utilizes substrates containing linear chains of α-1,2-linked mannotriose or mannotetraose. The recombinant enzyme consecutively transfers two mannosyl units on to these acceptors, leading to the production of α-mannosidase- resistant oligomannosides. NMR experiments further confirmed the presence of a terminal βMan (β-1,2-linked mannose) unit in the first enzyme product. In the future, a better understanding of specific β-1,2- mannosyltransferase molecular requirements will help the design of new potential antifungal drugs. © 2014 Biochemical Society. |
Cell-penetrating nanobiosensors for pointillistic intracellular Ca 2+-transient detection Article de journal A I Zamaleeva; M Collot; E Bahembera; C Tisseyre; P Rostaing; A V Yakovlev; M Oheim; M De Waard; J -M Mallet; A Feltz Nano Letters, 14 (6), p. 2994–3001, 2014. @article{Zamaleeva:2014, title = {Cell-penetrating nanobiosensors for pointillistic intracellular Ca 2+-transient detection}, author = {A I Zamaleeva and M Collot and E Bahembera and C Tisseyre and P Rostaing and A V Yakovlev and M Oheim and M De Waard and J -M Mallet and A Feltz}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84902283311&doi=10.1021%2fnl500733g&partnerID=40&md5=79a825c54db5f8e5f2eb4a0972aad1f7}, doi = {10.1021/nl500733g}, year = {2014}, date = {2014-01-01}, journal = {Nano Letters}, volume = {14}, number = {6}, pages = {2994--3001}, abstract = {Small-molecule chemical calcium (Ca2+) indicators are invaluable tools for studying intracellular signaling pathways but have severe shortcomings for detecting local Ca2+ entry. Nanobiosensors incorporating functionalized quantum dots (QDs) have emerged as promising alternatives but their intracellular use remains a major challenge. We designed cell-penetrating FRET-based Ca2+ nanobiosensors for the detection of local Ca2+ concentration transients, using commercially available CANdot565QD as a donor and CaRuby, a custom red-emitting Ca2+ indicator, as an acceptor. With Ca2+-binding affinities covering the range of 3-20 μM, our CaRubies allow building sensors with a scalable affinity for detecting intracellular Ca2+ transients at various concentrations. To facilitate their cytoplasmic delivery, QDs were further functionalized with a small cell-penetrating peptide (CPP) derived from hadrucalcin (HadUF1-11: H11), a ryanodine receptor-directed scorpion toxin identified within the venom of Hadrurus gertschi. Efficient internalization of QDs doubly functionalized with PEG5-CaRuby and H11 (in a molar ratio of 1:10:10, respectively) is demonstrated. In BHK cells expressing a N-methyl-d-aspartate receptor (NMDAR) construct, these nanobiosensors report rapid intracellular near-membrane Ca2+ transients following agonist application when imaged by TIRF microscopy. Our work presents the elaboration of cell-penetrating FRET-based nanobiosensors and validates their function for detection of intracellular Ca2+ transients. © 2014 American Chemical Society.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Small-molecule chemical calcium (Ca2+) indicators are invaluable tools for studying intracellular signaling pathways but have severe shortcomings for detecting local Ca2+ entry. Nanobiosensors incorporating functionalized quantum dots (QDs) have emerged as promising alternatives but their intracellular use remains a major challenge. We designed cell-penetrating FRET-based Ca2+ nanobiosensors for the detection of local Ca2+ concentration transients, using commercially available CANdot565QD as a donor and CaRuby, a custom red-emitting Ca2+ indicator, as an acceptor. With Ca2+-binding affinities covering the range of 3-20 μM, our CaRubies allow building sensors with a scalable affinity for detecting intracellular Ca2+ transients at various concentrations. To facilitate their cytoplasmic delivery, QDs were further functionalized with a small cell-penetrating peptide (CPP) derived from hadrucalcin (HadUF1-11: H11), a ryanodine receptor-directed scorpion toxin identified within the venom of Hadrurus gertschi. Efficient internalization of QDs doubly functionalized with PEG5-CaRuby and H11 (in a molar ratio of 1:10:10, respectively) is demonstrated. In BHK cells expressing a N-methyl-d-aspartate receptor (NMDAR) construct, these nanobiosensors report rapid intracellular near-membrane Ca2+ transients following agonist application when imaged by TIRF microscopy. Our work presents the elaboration of cell-penetrating FRET-based nanobiosensors and validates their function for detection of intracellular Ca2+ transients. © 2014 American Chemical Society. |
Copper-catalyzed olefinic C-Ħ difluoroacetylation of enamides Article de journal G Caillot; J Dufour; M -C Belhomme; T Poisson; L Grimaud; X Pannecoucke; I Gillaizeau Chemical Communications, 50 (44), p. 5887–5890, 2014. @article{Caillot:2014, title = {Copper-catalyzed olefinic C-{H} difluoroacetylation of enamides}, author = {G Caillot and J Dufour and M -C Belhomme and T Poisson and L Grimaud and X Pannecoucke and I Gillaizeau}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84899841967&doi=10.1039%2fc4cc01994f&partnerID=40&md5=f67ca166ba291488895380b82b81baf4}, doi = {10.1039/c4cc01994f}, year = {2014}, date = {2014-01-01}, journal = {Chemical Communications}, volume = {50}, number = {44}, pages = {5887--5890}, abstract = {Copper-catalyzed olefinic difluoroacetylation of enamides via direct C-H bond functionalization using BrCF2CO2Et is reported for the first time. It constitutes an efficient radical-free method for the regioselective synthesis of β-difluoroester substituted enamides which exhibits broad substrate scope, and thus demonstrates its potent application in a late stage fluorination strategy. This journal is © the Partner Organisations 2014.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Copper-catalyzed olefinic difluoroacetylation of enamides via direct C-H bond functionalization using BrCF2CO2Et is reported for the first time. It constitutes an efficient radical-free method for the regioselective synthesis of β-difluoroester substituted enamides which exhibits broad substrate scope, and thus demonstrates its potent application in a late stage fluorination strategy. This journal is © the Partner Organisations 2014. |
Benzoxazinone synthesis via Passerini-Smiles couplings Article de journal E Martinand-Lurin; L El Kaïm; L Grimaud Tetrahedron Letters, 55 (37), p. 5144–5146, 2014. @article{Martinand-Lurin:2014, title = {Benzoxazinone synthesis via Passerini-Smiles couplings}, author = {E Martinand-Lurin and L El Ka\"{i}m and L Grimaud}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84908249141&doi=10.1016%2fj.tetlet.2014.07.088&partnerID=40&md5=d5cb0878675db8f7218bfe35692ef6a3}, doi = {10.1016/j.tetlet.2014.07.088}, year = {2014}, date = {2014-01-01}, journal = {Tetrahedron Letters}, volume = {55}, number = {37}, pages = {5144--5146}, abstract = {Benzoxazinones are easily prepared using Passerini-Smiles couplings of o-nitrophenol derivatives. Palladium-catalyzed flow-hydrogenation of adducts gives aniline derivatives that cyclize into benzoxazinones on treatment with trifluoroacetic acid. ©2014 Elsevier Ltd. All rights reserved.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Benzoxazinones are easily prepared using Passerini-Smiles couplings of o-nitrophenol derivatives. Palladium-catalyzed flow-hydrogenation of adducts gives aniline derivatives that cyclize into benzoxazinones on treatment with trifluoroacetic acid. ©2014 Elsevier Ltd. All rights reserved. |
Double Smiles rearrangement of Passerini adducts towards benzoxazinones Article de journal E Martinand-Lurin; A Dos Santos; L El Kaim; L Grimaud; P Retailleau Chemical Communications, 50 (17), p. 2214–2217, 2014. @article{Martinand-Lurin:2014a, title = {Double Smiles rearrangement of Passerini adducts towards benzoxazinones}, author = {E Martinand-Lurin and A Dos Santos and L El Kaim and L Grimaud and P Retailleau}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84893490770&doi=10.1039%2fc3cc49022j&partnerID=40&md5=03aee59dae0fac6d8d96b5b34bc8f94c}, doi = {10.1039/c3cc49022j}, year = {2014}, date = {2014-01-01}, journal = {Chemical Communications}, volume = {50}, number = {17}, pages = {2214--2217}, abstract = {A new straightforward access to benzoxazinones based on a three-component coupling is presented here. The mechanism of the whole process involves a double aryl transfer as clearly underlined by the X-ray diffraction analysis of the products. © The Royal Society of Chemistry.}, keywords = {}, pubstate = {published}, tppubtype = {article} } A new straightforward access to benzoxazinones based on a three-component coupling is presented here. The mechanism of the whole process involves a double aryl transfer as clearly underlined by the X-ray diffraction analysis of the products. © The Royal Society of Chemistry. |
Kinetic data on the synergetic role of amines and water in the reduction of phosphine-ligated palladium(II) to palladium(0) Article de journal C Amatore; L El Kaïm; L Grimaud; A Jutand; A Meignié; G Romanov European Journal of Organic Chemistry, 2014 (22), p. 4709–4713, 2014. @article{Amatore:2014a, title = {Kinetic data on the synergetic role of amines and water in the reduction of phosphine-ligated palladium(II) to palladium(0)}, author = {C Amatore and L El Ka\"{i}m and L Grimaud and A Jutand and A Meigni\'{e} and G Romanov}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84904740230&doi=10.1002%2fejoc.201402519&partnerID=40&md5=2f0cf090265ba59f5cc2bcb663aeb36b}, doi = {10.1002/ejoc.201402519}, year = {2014}, date = {2014-01-01}, journal = {European Journal of Organic Chemistry}, volume = {2014}, number = {22}, pages = {4709--4713}, abstract = {Tertiary amines such as EtN(iPr)2 do not reduce [PdCl 2(PPh3)2] into a Pd0 complex. The latter is formed only after the addition of water (generation of HO -), as was reported by Grushin and Alper for NEt3. The mechanism of the PdII/Pd0 reduction performed in the presence of an excess amount of PPh3 is established quantitatively by means of electrochemical techniques that provide kinetic data (determination of the equilibrium and rate constants) for the disappearance of [PdCl 2(PPh3)2] and the formation of [Pd 0(PPh3)3]. [PdCl(OH)(PPh3) 2] is formed, which allows reductive elimination between OH and the ligated PPh3 (zero-order reaction for PPh3), and this leads to a Pd0 complex. The reducing agent is ligated PPh 3, which ultimately yields (O)PPh3. The rate of the overall reduction process is controlled by the amount of water that imposes the concentration of HO-. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Tertiary amines such as EtN(iPr)2 do not reduce [PdCl 2(PPh3)2] into a Pd0 complex. The latter is formed only after the addition of water (generation of HO -), as was reported by Grushin and Alper for NEt3. The mechanism of the PdII/Pd0 reduction performed in the presence of an excess amount of PPh3 is established quantitatively by means of electrochemical techniques that provide kinetic data (determination of the equilibrium and rate constants) for the disappearance of [PdCl 2(PPh3)2] and the formation of [Pd 0(PPh3)3]. [PdCl(OH)(PPh3) 2] is formed, which allows reductive elimination between OH and the ligated PPh3 (zero-order reaction for PPh3), and this leads to a Pd0 complex. The reducing agent is ligated PPh 3, which ultimately yields (O)PPh3. The rate of the overall reduction process is controlled by the amount of water that imposes the concentration of HO-. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. |
Nitrile synthesis through catalyzed cascades involving acid-nitrile exchange Article de journal D Cartigny; A Dos Santos; L El Kaïm; L Grimaud; R Jacquot; P Marion Synthesis (Germany), 46 (13), p. 1802–1806, 2014. @article{Cartigny:2014, title = {Nitrile synthesis through catalyzed cascades involving acid-nitrile exchange}, author = {D Cartigny and A Dos Santos and L El Ka\"{i}m and L Grimaud and R Jacquot and P Marion}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84903280050&doi=10.1055%2fs-0033-1341227&partnerID=40&md5=38295775dfa78bb1174ab1e635f6a792}, doi = {10.1055/s-0033-1341227}, year = {2014}, date = {2014-01-01}, journal = {Synthesis (Germany)}, volume = {46}, number = {13}, pages = {1802--1806}, abstract = {Irreversible acid-nitrile exchange reactions using both glutaronitrile and (phenylsulfonyl)acetonitrile may be catalyzed by Lewis acids. Whereas a cyclization towards imides displaces the equilibria in the reaction with dinitriles, a decarboxylation step is involved when using the (phenylsulfonyl)acetonitrile. © Georg Thieme Verlag Stuttgart New York.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Irreversible acid-nitrile exchange reactions using both glutaronitrile and (phenylsulfonyl)acetonitrile may be catalyzed by Lewis acids. Whereas a cyclization towards imides displaces the equilibria in the reaction with dinitriles, a decarboxylation step is involved when using the (phenylsulfonyl)acetonitrile. © Georg Thieme Verlag Stuttgart New York. |
The Ugi-Smiles and Passerini-Smiles couplings: A story about phenols in isocyanide-based multicomponent reactions Article de journal L El Kaïm; L Grimaud European Journal of Organic Chemistry, 2014 (35), p. 7749–7762, 2014. @article{ElKaim:2014, title = {The Ugi-Smiles and Passerini-Smiles couplings: A story about phenols in isocyanide-based multicomponent reactions}, author = {L El Ka\"{i}m and L Grimaud}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84918806715&doi=10.1002%2fejoc.201402783&partnerID=40&md5=b42a0275c796d8a0cd972465d2cec247}, doi = {10.1002/ejoc.201402783}, year = {2014}, date = {2014-01-01}, journal = {European Journal of Organic Chemistry}, volume = {2014}, number = {35}, pages = {7749--7762}, abstract = {The Ugi-Smiles and Passerini-Smiles couplings are extensions of Ugi and Passerini reactions involving the use of acidic phenols in place of the traditional carboxylic acid partners. A Smiles rearrangement is in each case responsible for the final N-aryl carboxamide formation. All the available data on the mechanisms and the scope of these reactions are presented. To demonstrate the interest of Ugi-Smiles and Passerini-Smiles couplings, these reactions have been further applied to the preparation of various fused heterocyclic systems. These "post-condensation" studies are also covered in this review. © 2014 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.}, keywords = {}, pubstate = {published}, tppubtype = {article} } The Ugi-Smiles and Passerini-Smiles couplings are extensions of Ugi and Passerini reactions involving the use of acidic phenols in place of the traditional carboxylic acid partners. A Smiles rearrangement is in each case responsible for the final N-aryl carboxamide formation. All the available data on the mechanisms and the scope of these reactions are presented. To demonstrate the interest of Ugi-Smiles and Passerini-Smiles couplings, these reactions have been further applied to the preparation of various fused heterocyclic systems. These "post-condensation" studies are also covered in this review. © 2014 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim. |
Three roles for the fluoride ion in palladium-catalyzed hiyama reactions: Transmetalation of [ArPdFL2] by Ar'Si(OR)3 Article de journal C Amatore; L Grimaud; G Le Duc; A Jutand Angewandte Chemie - International Edition, 53 (27), p. 6982–6985, 2014. @article{Amatore:2014b, title = {Three roles for the fluoride ion in palladium-catalyzed hiyama reactions: Transmetalation of [ArPdFL2] by Ar'Si(OR)3}, author = {C Amatore and L Grimaud and G Le Duc and A Jutand}, url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84903206513&doi=10.1002%2fanie.201400956&partnerID=40&md5=414f0f35969f8267886c644e413e89ae}, doi = {10.1002/anie.201400956}, year = {2014}, date = {2014-01-01}, journal = {Angewandte Chemie - International Edition}, volume = {53}, number = {27}, pages = {6982--6985}, abstract = {From the kinetic data on the transmetalation/reductive elimination in fluoride-promoted Hiyama reactions, obtained using electrochemical techniques, it has been established that fluoride ions play three roles. F- reacts with trans-[ArPdBrL2] (L=PPh3) to form trans-[ArPdFL2], which reacts with Ar'Si(OMe)3 in the rate-determining transmetalation, whereas trans-[ArPdBrL2] does not react with Ar'Si(OMe)3. F- reacts with Ar'Si(OMe) 3 to deliver the unreactive silicate Ar'SiF(OMe)3 -, thus leading to two antagonistic kinetic effects. In addition, F- catalyzes the reductive elimination from intermediate trans-[ArPdAr'L2]. Role playing: F- favors the Hiyama reaction by formation of trans-[ArPdF(PPh3)2], which reacts with Ar'Si(OMe)3 in the rate-determining transmetalation, and by promoting the reductive elimination from the intermediate trans-[ArPdAr'(PPh3)2]. Conversely, F- disfavors the reaction by formation of the unreactive [Ar'SiF(OMe) 3]-, thus leading to two antagonistic effects of F -. As a consequence, [F-]/[Ar'Si(OMe)3] has to be less than unity. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.}, keywords = {}, pubstate = {published}, tppubtype = {article} } From the kinetic data on the transmetalation/reductive elimination in fluoride-promoted Hiyama reactions, obtained using electrochemical techniques, it has been established that fluoride ions play three roles. F- reacts with trans-[ArPdBrL2] (L=PPh3) to form trans-[ArPdFL2], which reacts with Ar'Si(OMe)3 in the rate-determining transmetalation, whereas trans-[ArPdBrL2] does not react with Ar'Si(OMe)3. F- reacts with Ar'Si(OMe) 3 to deliver the unreactive silicate Ar'SiF(OMe)3 -, thus leading to two antagonistic kinetic effects. In addition, F- catalyzes the reductive elimination from intermediate trans-[ArPdAr'L2]. Role playing: F- favors the Hiyama reaction by formation of trans-[ArPdF(PPh3)2], which reacts with Ar'Si(OMe)3 in the rate-determining transmetalation, and by promoting the reductive elimination from the intermediate trans-[ArPdAr'(PPh3)2]. Conversely, F- disfavors the reaction by formation of the unreactive [Ar'SiF(OMe) 3]-, thus leading to two antagonistic effects of F -. As a consequence, [F-]/[Ar'Si(OMe)3] has to be less than unity. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. |
Anti-oxidant Mn-complexes: evaluation in cellular models of oxidative stress Article de journal Clotilde Policar; Anne-Sophie Bernard; Nicolas Delsuc; Geraldine Gazzah; Manon Guille; Frederic Lemaitre; Christian Amatore; Maria Bachelet; Joelle Masliah Journal of Biological Inorganic Chemistry, 19 , p. S739-S740, 2014, (Times Cited: 0 2 12th European Biological Inorganic Chemistry Conference (EuroBIC) Aug 24-28, 2014 Zurich, SWITZERLAND Univ Zurich). @article{, title = {Anti-oxidant Mn-complexes: evaluation in cellular models of oxidative stress}, author = {Clotilde Policar and Anne-Sophie Bernard and Nicolas Delsuc and Geraldine Gazzah and Manon Guille and Frederic Lemaitre and Christian Amatore and Maria Bachelet and Joelle Masliah}, year = {2014}, date = {2014-01-01}, journal = {Journal of Biological Inorganic Chemistry}, volume = {19}, pages = {S739-S740}, note = {Times Cited: 0 2 12th European Biological Inorganic Chemistry Conference (EuroBIC) Aug 24-28, 2014 Zurich, SWITZERLAND Univ Zurich}, keywords = {}, pubstate = {published}, tppubtype = {article} } |