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  • B. Neil, F. Lucien, L. Fensterbank, and C. Chauvier, “Transition-Metal-Free Silylation of Unactivated C(sp2)–H Bonds with tert-Butyl-Substituted Silyldiazenes”, ACS Catalysis, vol. 11, no. 21, p. 13085-13090, Nov. 2021.
    Abstract: Aromatic organosilanes bearing C(sp2)–Si bonds have found increasing applications across the chemical science, yet are mostly produced by atom-uneconomical stoichiometric procedures. Catalytic alternatives using hydrosilanes as silicon sources have also been described, but they display unfavorable thermodynamics and are mostly based on expensive catalytic systems, often derived from noble metals, or lack generality. Herein, we describe the use of an alternative silicon source, namely the tert-butyl-substituted silyldiazenes (tBu–N═N–SiR3), that are readily accessible from commercially available precursors and whose structure enables the C(sp2)–H bond silylation of unactivated heteroaryl and aryl compounds under ambient, transition-metal-free catalytic conditions.
    Tags: MACO, POLE 1.

  • C. Passirani, A. Vessières, G. La Regina, W. Link, and R. Silvestri, “Modulating undruggable targets to overcome cancer therapy resistance”, Drug Resistance Updates, p. 100788, Dec. 2021.
    Abstract: Many cancer patients frequently fail to respond to anti-cancer treatment due to therapy resistance which is the major obstacle towards curative cancer treatment. Therefore, identification of the molecular mechanisms underlying resistance is of paramount clinical and economic importance. The advent of targeted therapies based on a molecular understanding of cancer could serve as a model for strategies to overcome drug resistance. Accordingly, the identification and validation of proteins critically involved in resistance mechanisms represent a path towards innovative therapeutic strategies to improve the clinical outcome of cancer patients. In this review, we discuss emerging targets, small molecule therapeutics and drug delivery strategies to overcome therapy resistance. We focus on rational treatment strategies based on transcription factors, pseudokinases, nuclear export receptors and immunogenic cell death strategy. Historically, unliganded transcription factors and pseudokinases were considered undruggable while blocking the nuclear export e.g., through inhibition of the nuclear export receptor CRM1 was predicted as highly toxic. Recent success inhibiting Gli-1, HIF-1α, HIF-2α and reactivating the tumor suppressor transcription factors p53 and FOXO illustrates the feasibility and power of this targeting approach. Similarly, progress has been made in modulating the activity of pseudokinase proteins implicated in therapy resistance including members of the Tribbles protein family. On the other hand, the recent clinical approval of Selinexor, a specific inhibitor of CRM-1, a protein that mediates the transport of cargos with leucine-rich nuclear export signals and known to be a driver of drug resistance, represents the proof-of-concept for inhibiting the nuclear export as a feasible strategy to overcome therapy resistance. The ever-growing capacity to target resistance mechanisms with judiciously selected small molecules, some of which are being formulated within smart nanoparticles, will pave the way towards the improvement of the clinical outcome and realize the full potential of targeted therapies and immunotherapies.
    Tags: Cancer, CHEMBIO, drug development, drug resistance, nanomedicine, POLE 3, therapeutic targets.

  • G. Passos Gomes, G. Xu, X. Zhu, L. ‐M. Chamoreau, Y. Zhang, O. Bistri‐Aslanoff, S. Roland, I. V. Alabugin, and M. Sollogoub, “Mapping C−H⋅⋅⋅M Interactions in Confined Spaces: (α‐ICyD <sup>Me</sup> )Au, Ag, Cu Complexes Reveal “Contra‐electrostatic H Bonds” Masquerading as Anagostic Interactions**”, Chemistry – A European Journal, p. chem.202100263, May 2021.

  • V. Pellas, J. Blanchard, C. Guibert, J. - M. Krafft, A. Miche, M. Salmain, and S. Boujday, “Gold Nanorod Coating with Silica Shells Having Controlled Thickness and Oriented Porosity: Tailoring the Shells for Biosensing”, ACS Applied Nano Materials, Aug. 2021.
    Abstract: The coating of gold nanorods with a silica shell (AuNR@SiO2) is an effective way to extend their use in a wide variety of biomedical applications including biosensing, drug delivery and photothermal therapy. A silica shell offers numerous advantages as it provides more stability, frees the surface from toxic cetyltrimethylammonium bromide (CTAB), and preserves the rod shape under photothermal conditions. This shell needs to be very thin for applications such as plasmonic biosensing, while a thicker and porous shell is suited for drug encapsulation and further controlled release. We introduce herein a strategy to perform silica coating based on dissociation of tetraethylorthosilicate (TEOS) hydrolysis and condensation reactions. This dissociation is achieved by a pH modulation of the reaction medium, and, depending on selected pH conditions, AuNR@SiO2 with a thick silica shell having an organized mesoporosity aligned either parallel (AuNR@//m-SiO2) or perpendicular (AuNR@⊥m-SiO2) to the AuNR surface was generated. Moreover, when mercaptopropyltrimethoxysilane (MPTMS) was used as a surface primer prior to TEOS condensation, ultrathin and homogeneous silica shells (AuNR@t-SiO2) of controllable thickness in the range 2–6 nm were produced. While formation, at high TEOS concentration, of core-free silica nanoparticles is evidenced by TEM analysis before the purification procedure, their total elimination during the purification step was achieved by addition of a suitable amount of CTAB to ensure the colloidal stability of the core-free and core–shell nanoparticles. Complete elimination of CTAB from AuNR@SiO2 was demonstrated by XPS, Raman, and ζ-potential measurements. Finally, the efficiency of AuNR@t-SiO2 in label-free plasmonic biosensing of a model target was demonstrated and their refractive index sensitivity factor was improved by 30% compared to CTAB-capped AuNRs.
    Tags: CHEMBIO, POLE 3.

  • C. Przybylski and V. Bonnet, “Discrimination of isomeric trisaccharides and their relative quantification in honeys using trapped ion mobility spectrometry”, Food Chemistry, vol. 341, p. 128182, 2021.

  • J. P. Rada, J. Forté, G. Gontard, C. - M. Bachelet, N. A. Rey, M. Salmain, and V. Corcé, “Novel luminescent benzopyranothiophene- and BODIPY-derived aroylhydrazonic ligands and their dicopper(II) complexes: syntheses, antiproliferative activity and cellular uptake studies”, Journal of biological inorganic chemistry: JBIC: a publication of the Society of Biological Inorganic Chemistry, vol. 26, no. 6, p. 675-688, Sep. 2021.
    Abstract: Two novel unsymmetrical binucleating aroylhydrazonic ligands and four dicopper(II) complexes carrying fluorescent benzopyranothiophene (BPT) or boron dipyrromethene (BODIPY) entities were synthesized and fully characterized. Complex 1, derived from the BPT-containing ligand H3L1, had its crystal structure elucidated through X-ray diffraction measurements. The absorption and fluorescence profiles of all the compounds obtained were discussed. Additionally, the stability of the ligands and complexes was monitored by UV-vis spectroscopy in DMSO and biologically relevant media. All the compounds showed moderate to high cytotoxicity towards the triple negative human breast cancer cell line MDA-MB-231. BPT derivatives were the most cytotoxic, specially H3L1, reaching an IC50 value up to the nanomolar range. Finally, fluorescence microscopy imaging studies employing mitochondria- and nucleus-staining dyes showed that the BODIPY-carrying ligand H3L2 was highly cell permeant and suggested that the compound preferentially accumulates in the mitochondria.
    Tags: Anticancer agents, Aroylhydrazones, Cellular uptake, CHEMBIO, Copper complexes, Cytotoxicity, POLE 3.

  • R. Ramos, J. - F. Gilles, R. Morichon, C. Przybylski, B. Caron, C. Botuha, A. Karaiskou, M. Salmain, and J. Sobczak-Thépot, “Cytotoxic BODIPY-Appended Half-Sandwich Iridium(III) Complex Forms Protein Adducts and Induces ER Stress”, Journal of Medicinal Chemistry, vol. 64, no. 22, p. 16675-16686, Nov. 2021.
    Abstract: Half-sandwich complexes of iridium(III) are currently being developed as anticancer drug candidates. In this context, we introduce IrBDP for which the C^N chelating phenyloxazoline ligand carries a fluorescent and lipophilic BODIPY reporter group, designed for intracellular tracking and hydrophobic compartment tropism. High-resolution analysis of cells cultured with IrBDP showed that it quickly permeates the plasma membrane and accumulates in the mitochondria and endoplasmic reticulum (ER), generating ER stress, dispersal of the Golgi apparatus, cell proliferation arrest and apoptotic cell death. Moreover, IrBDP forms fluorescent adducts with a subset of amino acids, namely histidine and cysteine, via coordination of N or S donor atoms of their side chains. Consistently, in vivo formation of covalent adducts with specific proteins is demonstrated, providing a molecular basis for the observed cytotoxicity and cellular response. Collectively, these results provide a new entry to the development of half-sandwich iridium-based anticancer drugs.
    Tags: CHEMBIO, POLE 3.

  • E. Rathahao-Paris, S. Alves, and A. Paris, “High-Throughput Metabolomics Using Flow Injection Analysis and Fourier Transform Ion Cyclotron Resonance Mass Spectrometry”, in Metabolomics, vol. 159, New York, NY: Humana, 2021, p. 9-23.
    Abstract: The hyphenation of flow injection analysis (FIA) with Fourier transform ion cyclotron resonance mass spectrometry (FTICR-MS) is an efficient approach usable to perform high throughput and very high resolution metabolomic data acquisition. Instrumental and analytical conditions for performing FIA-MS are provided. The procedure to optimize dilution factor of biological samples as well as to evaluate quality of acquisition data are also described. In this protocol, urine is chosen as a matrix example to illustrate the application of procedures. Last, some indications on an adapted data processing are given.
    Tags: CSOB, POLE 3.

  • E. Romain, K. de la Vega-Hernández, F. Guégan, J. S. García, C. Fopp, F. Chemla, F. Ferreira, H. Gerard, O. Jackowski, S. Halbert, M. Oestreich, and A. Perez-Luna, “Development of a Radical Silylzincation of (Het)Aryl-Substituted Alkynes and Computational Insights into the Origin of the trans-Stereoselectivity”, Advanced Synthesis & Catalysis, vol. 363, no. 10, p. 2634-2647, 2021.
    Abstract: Aryl- and hetaryl-substituted acetylenes undergo regio- and stereoselective silylzincation by reaction with [(Me3Si)3Si]2Zn in the presence of Et2Zn (10–110 mol%) as additive. The distinctive feature of this addition across the C−C triple bond is its trans stereoselectivity. The radical nature of the silylzincation process is supported by diagnostic experiments and DFT calculations, which also corroborate the role played by steric effects to obtain that stereoselectivity. The procedure can be combined in one-pot with the copper(I)-mediated electrophilic substitution of the C(sp2)−Zn bond, with retention of the double bond geometry. This makes it valuable for the synthesis of stereodefined di- and trisubstituted vinylsilanes.
    Tags: POLE 1, Radical reactions, ROCS, Silylmetalation, Silylzinc reagents, Vinylsilanes, Zinc.
    Attachment Full Text PDF 5.6 Mb (source)

  • S. Topin-Ruiz, A. Mellinger, E. Lepeltier, C. Bourreau, J. Fouillet, J. Riou, G. Jaouen, L. Martin, C. Passirani, and N. Clere, “p722 ferrocifen loaded lipid nanocapsules improve survival of murine xenografted-melanoma via a potentiation of apoptosis and an activation of CD8+ T lymphocytes”, International Journal of Pharmaceutics, p. 120111, Jan. 2021.
    Abstract: Metastatic melanoma is a malignant tumor with a poor prognosis. Recent new therapeutics improved the survival of patients at a metastatic stage. However, the low response rate to immunotherapy, explained in part by resistance to apoptosis, needs to develop new strategies. The ferrocifen family represents promising bioorganometallic molecules for melanoma treatment since they show potent anticancer properties. The aim of this study is (i) to evaluate the benefits of a strategy involving encapsulated p722 in lipid nanocapsules (LNC) in B16F10 melanoma mice models and (ii) to compare the beneficial effects with an existing therapy such as anti-CTLA4 mAb. Interestingly, LNC-p722 induces a significant decrease of melanoma cell viability. In vivo data shows a significant improvement in the survival rate and a slower tumor growth with p722-loaded LNC in comparison with anti-CTLA4 mAb. Western blots confirm that LNC-p722 potentiates intrinsic apoptotic pathway. Treatment with LNC-p722 significantly activates CD8+ T lymphocytes compared to treatment with anti-CTLA4 mAb. This study uncovers a new therapeutic strategy with encapsulated p722 to prevent B16F10 melanoma growth and to improve survival of treated mice.
    Tags: apoptosis, CD8 T lymphocytes, CHEMBIO, Ferrocifen, metastatic melanoma, POLE 3.

  • G. Toupalas, J. Karlsson, F. A. Black, A. Masip‐Sánchez, X. López, Y. Ben M'Barek, S. Blanchard, A. Proust, S. Alves, P. Chabera, I. P. Clark, T. Pullerits, J. M. Poblet, E. A. Gibson, and G. Izzet, “Tuning Photoinduced Electron Transfer in POM‐Bodipy Hybrids by Controlling the Environment: Experiment and Theory”, Angewandte Chemie, vol. 133, no. 12, p. 6592-6599, Mar. 2021.

  • A. Vessières, E. Quissac, N. Lemaire, A. Alentorn, P. Domeracka, P. Pigeon, M. Sanson, A. Idbaih, and M. Verreault, “Heterogeneity of Response to Iron-Based Metallodrugs in Glioblastoma Is Associated with Differences in Chemical Structures and Driven by FAS Expression Dynamics and Transcriptomic Subtypes”, International Journal of Molecular Sciences, vol. 22, no. 19, p. 10404, Jan. 2021.
    Abstract: Glioblastoma (GBM) is the most frequent and deadliest primary brain cancer in adults, justifying the search for new treatments. Some members of the iron-based ferrocifen family have demonstrated a high cytotoxic effect on various cancer cell lines via innovative mechanisms of action. Here, we evaluated the antiproliferative activity by wst-1 assay of six ferrocifens in 15 molecularly diverse GBM patient-derived cell lines (PDCLs). In five out of six compounds, the half maximal inhibitory concentration (IC50) values varied significantly (10 nM &lt; IC50 &lt; 29.8 µM) while the remaining one (the tamoxifen-like complex) was highly cytotoxic against all PDCLs (mean IC50 = 1.28 µM). The pattern of response was comparable for the four ferrocifens bearing at least one phenol group and differed widely from those of the tamoxifen-like complex and the complex with no phenol group. An RNA sequencing differential analysis showed that response to the diphenol ferrocifen relied on the activation of the Death Receptor signaling pathway and the modulation of FAS expression. Response to this complex was greater in PDCLs from the Mesenchymal or Proneural transcriptomic subtypes compared to the ones from the Classical subtype. These results provide new information on the mechanisms of action of ferrocifens and highlight a broader diversity of behavior than previously suspected among members of this family. They also support the case for a molecular-based personalized approach to future use of ferrocifens in the treatment of GBM.
    Tags: biomarkers, bioorganometallic chemistry, CHEMBIO, death receptor signaling pathway, ferrocene, personalized medicine, POLE 3, targeted therapy.

  • A. Vessières, Y. Wang, M. J. McGlinchey, and G. Jaouen, “Multifaceted chemical behaviour of metallocene (M = Fe, Os) quinone methides. Their contribution to biology”, Coordination Chemistry Reviews, vol. 430, p. 213658, 2021.

  • Q. P. Xuan, J. Glatz, A. Benchohra, J. - R. Jiménez, R. Plamont, L. - M. Chamoreau, A. Flambard, Y. Li, L. Lisnard, D. Dambournet, O. J. Borkiewicz, M. - L. Boillot, L. Catala, A. Tissot, and R. Lescouëzec, “Building responsive materials by assembling {Fe4Co4} switchable molecular cubes”, Journal of Materials Chemistry C, vol. 9, no. 28, p. 8882-8890, Jul. 2021.
    Abstract: Responsive materials that can answer to chemical or physical external stimuli offer numerous prospects in material science. Here, we have elaborated a two-step synthetic approach that allows incorporating molecular cubic switches into a polymeric material. Firstly, a preformed half-capped, Cs+-templated {Fe4Co4} cyanido-polymetallic cubic unit (“pro-cube”) is obtained and proven to be stable in solution, as demonstrated by paramagnetic NMR. Secondly, the reaction of the pro-cube with a ditopic scorpionate ligand enables the precipitation of a polymeric network containing the cubic unit. Furthermore, the adequately chosen ditopic ligand that coordinates the Co ions of the pro-cube allows us to preserve the switchable properties of the cubic unit. Indeed, the magnetic properties of the polymeric material compare well with those of the molecular cubic model that is obtained by reacting a non-bridging scorpionate ligand, and that was prepared as a reference. Both the polymeric material and the molecular model cube show a thermally-induced metal–metal electron transfer near room temperature. Interestingly, the magnetic state of the polymeric material is shown to depend on its hydration state, indicating its capability to act as a chemo-sensor.
    Tags: ERMMES, POLE 2.

  • L. Zhang, M. - A. Arrio, S. Mazerat, L. Catala, W. Li, E. Otero, P. Ohresser, L. Lisnard, C. Cartier dit Moulin, T. Mallah, and P. Sainctavit, “Magnetic Hysteresis in a Monolayer of Oriented 6 nm CsNiCr Prussian Blue Analogue Nanocrystals”, Inorganic Chemistry, vol. 60, no. 21, p. 16388-16396, Nov. 2021.
    Abstract: Prussian blue analogue nanocrystals of the CsINiII[CrIII(CN)6] cubic network with 6 nm size were assembled as a single monolayer on highly organized pyrolytic graphite (HOPG). X-ray magnetic circular dichroism (XMCD) studies, at the Ni and Cr L2,3 edges, reveal the presence of an easy plane of magnetization evidenced by an opening of the magnetic hysteresis loop (coercive field of ≈200 Oe) when the magnetic field, B, is at 60° relative to the normal to the substrate. The angular dependence of the X-ray natural linear dichroism (XNLD) reveals both an orientation of the nanocrystals on the substrate and an anisotropy of the electronic cloud of the NiII and CrIII coordination sphere species belonging to the nanocrystals’ surface. Ligand field multiplet (LFM) calculations that reproduce the experimental data are consistent with an elongated tetragonal distortion of surface NiII coordination sphere responsible for the magnetic behavior of monolayer.
    Tags: ERMMES, POLE 2.

  • T. Zhang, A. Solé‐Daura, H. Fouilloux, J. M. Poblet, A. Proust, J. J. Carbó, and G. Guillemot, “Reaction Pathway Discrimination in Alkene Oxidation Reactions by Designed Ti-Siloxy-Polyoxometalates”, ChemCatChem, vol. 13, no. 4, p. 1220-1229, 2021.


  • Abdmouleh, Fatma, El Arbi, Mehdi, Hajer, Ben Saad, Jellali, Karim, Etata, Emna, Amara, Ibtissem Ben, Pigeon, Pascal, Hanen, Ben Hassen, Top, Siden, Jaouen, Gérard, Hammami, Riadh, Mamdouh, Ben Ali, and Gupta, Girish Kumar, “Antimicrobial, Antitumor and Side Effects Assessment of a Newly Synthesized Tamoxifen Analog”, Current Topics in Medicinal Chemistry, vol. 20, no. 25, p. 2281-2288, Sep. 2020.
    Abstract: Background: Tamoxifen citrate is a very prevalent drug marketed under several trade names like Apo-Tamox, Nolvadex, Tamec, Tamizam, and Tamoplex. This molecule is approved by the FDA for breast cancer treatment. Some studies have shown that tamoxifen has anti-tuberculosis and antiparasitic activities. Like any drug, tamoxifen possesses side effects, more or less dangerous. Aims: Basically, this work is a comparative study that aims to: primarily compare the antimicrobial and antitumor activities of tamoxifen and a newly synthesized tamoxifen analog; and to determine the molecule with lesser side effects. Methods: Three groups of mice were injected with tamoxifen citrate and compound 2(1,1-bis[4-(3- dimethylaminopropoxy)phenyl]-2-phenyl-but-1-ene dihydrochloride) at doses corresponding to C1 (1/10), C2 (1/50), and C3 (1/100) to compound 2 lethal dose (LD50 = 75 mg/kg) administered to adult mice. A group of noninjected mice served as a study control. Results: Experimental results suggest that compound 2 has better antitumor and antimicrobial activity than tamoxifen citrate besides its lower toxicity effects. Conclusion: The results obtained from the present study confirmed the antitumor and antimicrobial effect of tamoxifen citrate and its hematological side effects. Compound 2 seems to be more effective than tamoxifen citrate for antitumor and antimicrobial treatment while having less hematological side effects and less disruption of the blood biochemical parameters. These findings encourage us to perform further studies on compound 2 and test it for other therapeutic uses for which tamoxifen was found effective.
    Tags: POLE 3.

  • S. Alves, A. Paris, and E. Rathahao-Paris, “Mass spectrometry-based metabolomics for an in-depth questioning of human health”, in Advances in Clinical Chemistry, Elsevier, 2020, p. S0065242320300214.

  • N. Audureau, F. Coumes, J. - M. Guigner, T. P. T. Nguyen, C. Ménager, F. Stoffelbach, and J. Rieger, “Thermoresponsive properties of poly(acrylamide-co-acrylonitrile)-based diblock copolymers synthesized (by PISA) in water”, Polymer Chemistry, vol. 11, no. 37, p. 5998-6008, Sep. 2020.
    Abstract: In this present work, we report the synthesis of UCST-thermoresponsive diblock copolymers using reversible addition fragmentation chain transfer (RAFT) polymerization in aqueous media. A water-soluble poly(N,N-dimethylacrylamide) macromolecular chain transfer agent (PDMAc macroRAFT) is used to promote and control the copolymerization of acrylamide and acrylonitrile in water and obtain PDMAc-b-P(AAm-co-AN) diblock copolymers. The fAN,0 and the length of the thermosensitive block (DPn) are systematically varied, in order to study their influence on the thermoresponsiveness of the block copolymers. A good blocking efficiency is generally evidenced by size exclusion chromatography. Remarkably, amphiphilic copolymer nanoparticles are formed in situ for the highest fAN,0. This is indeed the first time that such particles are produced by a polymerization-induced self-assembly (PISA) process. The morphology of the in situ formed nanoparticles and their behavior with temperature are studied by means of dynamic light scattering (DLS), (cryogenic) transmission electron microscopy ((cryo-)TEM) and turbidimetry. Spherical and worm-like nanoparticles are formed which exhibit unexpected properties, such as an unprecedented heating-induced worm-to-sphere morphological transition in water.
    Tags: POLE 4, POLYMERES.
    Attachment Full Text PDF 1.7 Mb (source)

  • P. Bayat, D. Lesage, and R. B. Cole, “Tutorial: Ion activation in tandem Mass spectrometry using ultra-high resolition spectroscopy”, Mass Spectrometry Reviews, p. mas.21623, Feb. 2020.

  • L. Bedoin, S. Alves, and J. - F. Lambert, “Origins of Life and Molecular Information: Selectivity in Mineral Surface-Induced Prebiotic Amino Acid Polymerization”, ACS Earth and Space Chemistry, p. acsearthspacechem.0c00183, Sep. 2020.

  • A. Beghennou, K. Passador, A. Passador, V. Corcé, S. Thorimbert, and C. Botuha, “Synthetic Strategy Studies for a Concise Access to Functionalized Pyrano[4,3-b]pyridin-7-ones: An Entry to Semi-Rigid Analogs of Antihistamines”, European Journal of Organic Chemistry, vol. 2020, no. 36, p. 5880-5889, Sep. 2020.
    Abstract: We report short and efficient syntheses of polyfunctionalized 5,8-dihydro-7H-pyrano[4,3-b]pyridin-7-ones and 1,4-dihydro-3H-pyrano[4,3-c]pyridin-3-ones which can be considered as new aza analogs of 3-isochromanones and as promising scaffolds for medicinal chemistry. Depending on the nature of the substituent, three different and complementary synthetic methodologies were used allowing the introduction of significant diversity in the substituent on the lactone ring of the pyranopyridinones. The selective α-arylation of nitrile (SNAr) and tert-butyl ester enolate (Pd catalyzed) followed by an acidic mediated lactonisation gives access to original C8-functionalized pyrano[4,3-b]pyridin-7-ones and a seleno-mediated cyclization to C1-functionalized pyrano[4,3-c]pyridin-3-ones. We have also applied the outlined synthetic methodologies to the preparation of potential semi-rigid analogs of antihistamines.
    Tags: Antihistamines, CHEMBIO, Pinner reaction, POLE 3, Pyridopyridinones, Seleno-mediated cyclization, δ-Lactone.
    Note Note
    <p>doi: 10.1002/ejoc.202001016</p>

  • Y. Ben M’Barek, T. Rosser, J. Sum, S. Blanchard, F. Volatron, G. Izzet, R. Salles, J. Fize, M. Koepf, M. Chavarot-Kerlidou, V. Artero, and A. Proust, “Dye-Sensitized Photocathodes: Boosting Photoelectrochemical Performances with Polyoxometalate Electron Transfer Mediators”, ACS Applied Energy Materials, vol. 3, no. 1, p. 163-169, Jan. 2020.

  • A. Benchohra, C. Méthivier, J. Landoulsi, D. Kreher, and R. Lescouëzec, “Electrospray ionization: an efficient approach to deposit polymetallic molecular switches onto gold surfaces”, Chemical Communications, vol. 56, no. 48, p. 6587-6589, 2020.
    Abstract: Electrospray ionization (EI) deposition is proven efficient in obtaining monolayers of a polymetallic charge transfer complex on gold surfaces. , Electrospray ionization (EI) deposition is proven efficient in obtaining monolayers of a polymetallic charge transfer complex on gold surfaces. The molecule's integrity is monitored by using PM-IRRAS and XPS. This approach broadens the perspective of molecular magnetic switch deposition, which is currently dominated by the thermal evaporation of monometallic spin crossover (SCO) complexes.
    Tags: ERMMES, POLE 2.

  • B. Bertrand, C. Botuha, J. Forté, H. Dossmann, and M. Salmain, “A bis-chelating (O^N^O)/(N^N) ligand for the synthesis of heterobimetallic Pt(II)/Re(I) complexes: tools for the optimization of a new class of Pt(II) anticancer agents.”, Chemistry – A European Journal, vol. 26, no. 56, p. 12846-12861, Jun. 2020.
    Abstract: The two independent (O^N^O) and (N^N) coordination sites of a newly synthesized bis 2-(hydroxyphenyl)-1,2,4-triazole platform have been exploited to prepare four monometallic neutral (O^N^O)Pt(II) complexes carrying DMSO, pyridine, triphenylphosphine or N-heterocyclic carbene (NHC) as fourth ligand. Then the second (N^N) coordination site was used to introduce an IR-active rhenium tricarbonyl entity, affording the four corresponding heterobimetallic neutral Pt(II)/Re(I) complexes as well as a cationic Pt(II)/Re(I) derivative. X-ray crystallographic studies showed that distortion of the organic platform occurred to accommodate the coordination geometry of both metal centers. No ligand exchange and no transchelation occurred upon incubation of the Pt(II) complexes in aqueous environment or in the presence of Fe(III), respectively. The ligand and the complexes antiproliferative activity was first screened on the triple negative breast cancer cell line MDA-MB-231. Then the IC 50 of the most active candidates was determined on a wider panel of human cancer cells (MDA-MB-231, MCF-7 and A2780) as well as on a non-tumorigenic cell line (MCF-10F). Low micromolar activities were reached for the complexes carrying a DMSO ligand, making them the first examples of highly active though hydrolytically stable Pt(II) complexes. Finally, the characteristic mid-IR signature of the Re(CO) 3 fragment in the Pt/Re heterobimetallic complexes was used to quantify their uptake in breast cancer cells.
    Tags: cancer, CHEMBIO, CSOB, heterobimetallic, pincer, platinum, POLE 3, rhenium.
    Note Note
    <p>doi: 10.1002/chem.202001752</p>

  • B. Bertrand, G. Gontard, C. Botuha, and M. Salmain, “Pincer-based heterobimetallic Pt(II)/Ru(II), Pt(II)/Ir(III) and Pt(II)/Cu(I) complexes: synthesis and evaluation antiproliferative properties”, European Journal of Inorganic Chemistry, vol. 2020, no. 35, p. 3370-3377, Sep. 2020.
    Abstract: Platinum pincer-based complexes [(O^N^O)Pt(L)] (L = DMSO, pyridine, triphenylphosphine or 1,3-dimethylbenzimidazol-2-ylidene) carrying an (N^N) coordination site were used as starting materials to synthesize a series of seven cationic heterobimetallic Pt(II)/Ru(II), Pt(II)/Ir(III) and Pt(II)/Cu(I) presenting a [( p- cymene)RuCl] + , a [(Cp*)IrCl] + (Cp* = ? 5 -pentamethylcyclopentadienyl) and a [(NHC iPr )Cu] + (NHC iPr = 1,3-bis(2,6-diisopropylphenyl)imidazole-2-ylidene) moiety respectively. The X-ray structure of one of the bimetallic Pt(II)/Ir(III) complexes showed a distortion of the organic platform to accommodate the coordination geometry of both metal centers as already observed for previous Pt(II)/Re(I) complexes. The antiproliferative activity of the complexes was first screened on the triple negative breast cancer cell line MDA-MB-231. Then the IC 50 of the most active candidates was determined on a wider panel of human cancer cells (MDA-MB-231, MCF-7 and A2780) as well as on a non-tumorigenic cell line (MCF-10A). The most toxic compound, namely the Pt(II)/Cu(I) heterobimetallic complex 4c showed an antiproliferative activity down to the nanomolar level.
    Tags: Bioorganometallic chemistry, cancer, CHEMBIO, heterobimetallic complexes, platinum, POLE 3, Synthesis.
    Note Note
    <p>doi: 10.1002/ejic.202000717</p>

  • P. Biais, O. Colombani, L. Bouteiller, F. Stoffelbach, and J. Rieger, “Unravelling the formation of BAB block copolymer assemblies during PISA in water”, Polymer Chemistry, vol. 11, no. 28, p. 4568-4578, Jul. 2020.
    Abstract: The mechanism of formation of associative BAB triblock copolymers through aqueous polymerization-induced self-assembly (PISA) is investigated for the first time, on copolymers constituted of a hydrophilic poly(N,N-dimethylacrylamide) block (PDMAc = block A) and a hydrophobic poly(diacetone acrylamide) block (PDAAm = block B). Such BAB copolymers tend to form bridged micelles/networks, which was expected to make the PISA process much more complex than for conventional diblock copolymers. Kinetic monitoring, light scattering analyses and macroscopic observations allowed identifying crucial parameters that influence the polymerization and the final dispersion properties, notably the stirring of the polymerization medium, the macroRAFT agent concentration, its ionization degree (related to the pH) and its Z group alkyl chain length.
    Tags: POLE 4, POLYMERES.
    Attachment Full Text PDF 2.7 Mb (source)

  • A. Bordes, A. Poveda, T. Troadec, A. Franconetti, A. Ardá, F. Perrin, M. Ménand, M. Sollogoub, J. Guillard, J. Désiré, R. Tripier, J. Jiménez-Barbero, and Y. Blériot, “Synthesis, Conformational Analysis, and Complexation Study of an Iminosugar-Aza-Crown, a Sweet Chiral Cyclam Analog”, Organic Letters, vol. 22, no. 6, p. 2344-2349, Mar. 2020.

  • G. Bouhalleb, A. Meddeb, N. F. Bourguiba, J. Legros, G. Poli, and F. Rezgui, “First Zinc Bromide Promoted Annulative Domino Reactions between Enamines and Cyclic Morita–Baylis–Hillman Alcohols: Synthesis of N,O-Ketals”, Synlett, vol. 31, no. 13, p. 1282-1286, Aug. 2020.
    Abstract: A new efficient ZnBr2-mediated annulative domino reaction between enamines and cyclic Morita–Baylis–Hillman (MBH) alcohols is disclosed. The process involves a tandem sequence (intermolecular conjugate addition of enamines to MBH alcohols and intramolecular nucleophilic addition of the hydroxyl moiety to the transiently generated iminium ion), affording the corresponding N,O-ketals diastereoselectively in good yields.
    Tags: conjugate addition, domino reactions, enamines, ketals, Key words MBH alcohol, N,O, POLE 1, ROCS, zinc bromide.
    Attachment Full Text PDF 233.1 kb (source)

  • A. Cartier, E. Levernier, A. - L. Dhimane, T. Fukuyama, C. Ollivier, I. Ryu, and L. Fensterbank, “Synthesis of Aliphatic Amides through a Photoredox Catalyzed Radical Carbonylation Involving Organosilicates as Alkyl Radical Precursors”, Advanced Synthesis & Catalysis, vol. 362, no. 11, p. 2254-2259, 2020.
    Abstract: Alkyl radicals, from primary to tertiary, formed by photocatalyzed oxidation of organosilicates, are involved efficiently in radical carbonylation with carbon monoxide (CO), in the presence of various amines and CCl4, leading to a variety of amides in moderate to good yields.
    Tags: Carbonylation, MACO, multi-component reaction, photooxidative catalysis, POLE 1, radical/polar, silicates.
    Attachment Full Text PDF 4.8 Mb (source)

  • M. S. Centellas, M. Piot, R. Salles, A. Proust, L. Tortech, D. Brouri, S. Hupin, B. Abécassis, D. Landy, C. Bo, and G. Izzet, “Exploring the self-assembly of dumbbell-shaped polyoxometalate hybrids, from molecular building units to nanostructured soft materials”, Chemical Science, vol. 11, no. 40, p. 11072-11080, Oct. 2020.
    Abstract: The formation of hierarchical nanostructures using preformed dumbbell-like species made of covalent organic–inorganic polyoxometalate (POM)-based hybrids is herein described. In this system, the presence of charged subunits (POM, metal linkers, and counter ions) in the complex molecular architecture can drive their aggregation, which results from a competition between the solvation energy of the discrete species and intermolecular electrostatic interactions. We show that the nature of the POM and the charge of the metal linker are key parameters for the hierarchical nanoorganization. The experimental findings were corroborated with a computational investigation combining DFT and molecular dynamics simulation methods, which outlines the importance of solvation of the counter ion and POM/counter ion association in the aggregation process. The dumbbell-like species can also form gels, in the presence of a poorer solvent, displaying similar nanoorganization of the aggregates. We show that starting from the designed molecular building units whose internal charges can be controlled by redox trigger we can achieve their implementation into soft nanostructured materials through the control of their supramolecular organization.
    Tags: E-POM, POLE 2.
    Attachment Snapshot 798 kb (source)
    Attachment Full Text PDF 943.8 kb (source)

  • Y. Chang, Y. Yuan, Q. Zhang, Y. Rong, Y. Yang, M. Chi, Z. Liu, Y. Zhang, P. Yu, and Y. Teng, “Effects of an isatin derivative on tumor cell migration and angiogenesis”, RSC Advances, vol. 10, no. 2, p. 1191-1197, 2020.
    Abstract: Compound 5-61 , a 5-(2-carboxyethenyl)isatin derivative was previously shown to have potent anticancer activity. Its effect on angiogenesis was further explored in this study. , Compound 5-61 , a 5-(2-carboxyethenyl)isatin derivative was previously shown to have potent anticancer activity. Its effect on angiogenesis was further explored in this study. Notably, 5-61 showed selective cytotoxicity against liver hepatocellular carcinoma HepG-2 cells (IC 50 = 7.13 nM). 5-61 powerfully induced apoptosis and G 2 /M phase arrest as well as inhibited the migration of HepG2 cells. Additionally, 5-61 clearly diminished tube formation and the actin arrangement in HUVECs. The physiological anti-angiogenic effects of 5-61 were further assessed by chick chorioallantoic membrane assays in vivo . The effects exerted by 5-61 were found to be mediated by VEGF along with its downstream signaling pathways including the PI3K/Akt/mTOR pathway and mitogen-activate protein kinase pathways (ERK). These results suggested that 5-61 is a potential tumor angiogenesis inhibitor that functions by interrupting the auto-phosphorylation of AKT, mTOR, and ERK 1/2.
    Tags: GOBS, POLE 3.

  • Y. Chen, X. Wang, Y. Zhu, L. Si, B. Zhang, Y. Zhang, L. Zhang, D. Zhou, and S. Xiao, “Synthesis of a Hexavalent Betulinic Acid Derivative as a Hemagglutinin-Targeted Influenza Virus Entry Inhibitor”, Molecular Pharmaceutics, vol. 17, no. 7, p. 2546-2554, Jul. 2020.

  • R. B. Cole, P. Bayat, J. S. Murray, C. Albers, and D. Brombach, ““Conformation pinning” by anion attachment enabling separation of isomeric steroid monomers by ion mobility spectrometry”, Journal of Mass Spectrometry, vol. 55, no. 12, Dec. 2020.

  • F. Coumes, M. Balarezo, J. Rieger, and F. Stoffelbach, “Biobased Amphiphilic Block Copolymers by RAFT-Mediated PISA in Green Solvent”, Macromolecular Rapid Communications, vol. 41, no. 9, p. 2000002, 2020.
    Abstract: Biobased amphiphilic diblock copolymers are prepared thanks to the combination of reversible addition–fragmentation transfer (RAFT) polymerization and polymerization-induced self-assembly (PISA) in an eco-friendly solvent mixture. First, the formation of a poly(acrylic acid) macroRAFT agent (PAA-TTC) is performed in water at 70 °C. Then, in a series of experiments, the PAA-TTC macroRAFT agent is used directly, without purification, as both chain transfer agent and stabilizing agent in the RAFT-PISA of menthyl acrylate (MnA) in dispersion in an ethanol/water mixture. The polymerizations of MnA are fast with high final conversions and well-controlled amphiphilic diblock copolymers are synthesized. Stable, sub-micrometric spherical particles composed of the diblock copolymers are formed. The influence of the monomer concentration and the length of the solvophobic block on the diameter of the self-assemblies is studied by means of dynamic light scattering and cryogenic transmission electron-microscopy.
    Tags: amphiphilic copolymers, biobased monomers, dispersion polymerization, PISA, POLE 4, POLYMERES, RAFT.
    Attachment Full Text PDF 1.3 Mb (source)

  • Y. Cui, Y. Mao, J. Mao, and Y. Zhang, “Smart regioselectivity towards mono 6-hydroxyl α-cyclodextrin amphiphilic derivatives”, RSC Advances, vol. 10, no. 18, p. 10695-10702, 2020.
    Abstract: A smart regioselective CD modification is described. For mono 6-hydroxyl and penta-alkyl coexistence on the primary face of α-CD, no additional catalysis or enzyme process are needed, just via adjustment of the ratio of alkali to alkylation agent. , Following the trend of eco-friendly development, a smart regioselective modification is described herein, for mono 6-hydroxyl and penta-alkyl coexistence on the primary face of α-cyclodextrins with no additional catalysis or no enzyme process, just via the adjustment of the ratio of alkali to alkylation agent, with good yields. The novel procedure minimized the tedious protection, deprotection steps and provided useful intermediates for further cutting edge research. Thus, the scope of green and economical access is extended from penta-pentenyl substitution to C 4 –C 6 alkyl group substitution. It was speculated that the mechanism might be controlled by the concentration of alkali in the system and the steric effects of the electrophilic reagent RBr.
    Tags: GOBS, POLE 3.

  • L. Cunningham, Y. Wang, C. Nottingham, J. Pagsulingan, G. Jaouen, M. McGlinchey, and P. J. Guiry, “Enantioselective Synthesis of Planar Chiral Ferrocifens that Show Chiral Discrimination in Antiproliferative Activity on Breast Cancer Cells”, ChemBioChem, vol. 21, no. 20, p. 2974-2981, 2020.
    Abstract: The design and first enantioselective synthesis of a series of chiral ferrocifens and ferrociphenols was realised via enantioselective palladium-catalysed intramolecular direct C?H bond activation followed by McMurry coupling. Biological evaluation revealed moderate anticancer activities on breast cancer cells and evidence of chiral discrimination between enantiomers. Treatment of these novel ferrocifens with Ag 2 O revealed that these systems are unable to form a neutral quinone methide, yet still demonstrate marked antiproliferative properties versus both the hormone-dependent MCF-7 and hormone-independent MDA-MB-231 cell lines. This bioactivity arises from two mechanisms: Fenton-type chemistry and the anti-estrogenic activity associated with the tamoxifen-like structure.
    Tags: anti-cancer activity, asymmetric synthesis, CHEMBIO, Ferrocene, McMurry coupling, POLE 3.
    Note Note
    <p>doi: 10.1002/cbic.202000311</p>

  • F. D'Agosto, J. Rieger, and M. Lansalot, “RAFT-Mediated Polymerization-Induced Self-Assembly”, Angewandte Chemie International Edition, vol. 59, no. 22, p. 8368-8392, 2020.
    Abstract: After a brief history that positions polymerization-induced self-assembly (PISA) in the field of polymer chemistry, this Review will cover the fundamentals of the PISA mechanism. Furthermore, this Review will also give an overview of some of the features and limitations of RAFT-mediated PISA in terms of the choice of the components involved, the nature of the nanoobjects that can be obtained and how the syntheses can be controlled, as well as some potential applications.
    Tags: block copolymers, heterogeneous polymerization, morphology, PISA, POLE 4, POLYMERES, RAFT.
    Attachment Full Text PDF 4.4 Mb (source)

  • A. Delvaux, E. Rathahao‐Paris, and S. Alves, “An emerging powerful technique for distinguishing isomers: Trapped Ion Mobility Spectrometry ‐ Time‐of‐Flight Mass Spectrometry for a rapid characterization of estrogen isomers”, Rapid Communications in Mass Spectrometry, Aug. 2020.

  • S. Dhifaoui, M. Hajji, T. Guerfel, V. Marvaud, J. - C. Daran, I. Turowska-Tyrk, R. Bel-Hadj-Tahar, and H. Nasri, “Experimental and computational studies on the structure and properties of a novel low-spin iron(III) macrocyclic complex”, Molecular Crystals and Liquid Crystals, vol. 702, no. 1, p. 92-109, May 2020.

  • F. Ding, J. Fu, C. Tao, Y. Yu, X. He, Y. Gao, and Y. Zhang, “Recent Advances of Chitosan and its Derivatives in Biomedical Applications”, Current Medicinal Chemistry, vol. 27, no. 18, p. 3023-3045, Jun. 2020.
    Abstract: Chitosan is the second-most abundant natural polysaccharide. It has unique characteristics, such as biodegradability, biocompatibility, and non-toxicity. Due to the existence of its free amine group and hydroxyl groups on its backbone chain, chitosan can undergo further chemical modifications to generate Chitosan Derivatives (CDs) that permit additional biomedical functionality. Chitosan and CDs can be fabricated into various forms, including Nanoparticles (NPs), micelles, hydrogels, nanocomposites and nano-chelates. For these reasons, chitosan and CDs have found a tremendous variety of biomedical applications in recent years. This paper mainly presents the prominent applications of chitosan and CDs for cancer therapy/diagnosis, molecule biosensing, viral infection, and tissue engineering over the past five years. Moreover, future research directions on chitosan are also considered.
    Tags: GOBS, POLE 3.

  • B. Doistau, L. Benda, J. - L. Cantin, O. Cador, F. Pointillart, W. Wernsdorfer, L. - M. Chamoreau, V. Marvaud, B. Hasenknopf, and G. Vives, “Dual switchable molecular tweezers incorporating anisotropic MnIII–salphen complexes”, Dalton Transactions, vol. 49, no. 26, p. 8872-8882, Jul. 2020.
    Abstract: An alternative strategy for the synthesis of terpyridine based switchable molecular tweezers has been developed to incorporate anisotropic Mn(III)–salphen complexes. The free ligand was synthesized using a building block strategy based on Sonogashira coupling reactions and was then selectively metalated with manganese in a last step. The conformation of the tweezers was switched from an open ‘W’ shaped form to a closed ‘U’ form by Zn(II) coordination to the terpyridine unit bringing the two Mn–salphen moieties in close spatial proximity as confirmed by X-ray crystallography. An alternate switching mechanism was observed by the intercalation of a bridging cyanide ligand between the two Mn–salphen moieties that resulted in the closing of the tweezers. These dual stimuli are attractive for achieving multiple controls of the mechanical motion of the tweezers. A crystallographic structure of unexpected partially oxidized closed tweezers was also obtained. One of the two Mn–salphen moieties underwent a ligand-centered oxidation of an imino to an amido group allowing an intramolecular Mn–Oamide–Mn linkage. The magnetic properties of the manganese(III) dimers were investigated to evaluate the magnetic exchange interaction and analyze the single molecule magnet behavior.
    Tags: E-POM, GOBS, POLE 2, POLE 3.
    Attachment Snapshot 876.4 kb (source)
    Attachment Full Text PDF 4.2 Mb (source)

  • H. Dossmann, D. Gatineau, H. Clavier, A. Memboeuf, D. Lesage, and Y. Gimbert, “Exploring Phosphine Electronic Effects on Molybdenum Complexes: A Combined Photoelectron Spectroscopy and Energy Decomposition Analysis Study”, The Journal of Physical Chemistry A, p. acs.jpca.0c06746, Oct. 2020.

  • H. Du, F. A. de Oliveira, L. J. C. Albuquerque, G. Tresset, E. Pavlova, C. Huin, P. Guégan, and F. C. Giacomelli, “Polyglycidol-Stabilized Nanoparticles as a Promising Alternative to Nanoparticle PEGylation: Polymer Synthesis and Protein Fouling Considerations”, Langmuir, vol. 36, no. 5, p. 1266-1278, Feb. 2020.
    Abstract: We herein demonstrate the outstanding protein-repelling characteristic of star-like micelles and polymersomes manufactured from amphiphilic block copolymers made by poly(butylene oxide) (PBO) hydrophobic segments and polyglycidol (PGL) hydrophilic outer shells. Although positively charged proteins (herein modeled by lysozyme) may adsorb onto the surface of micelles and polymersomes where the assemblies are stabilized by short PGL chains (degree of polymerization smaller than 15), the protein adsorption vanishes when the degree of polymerization of the hydrophilic segment (PGL) is higher than ∼20, regardless the morphology. This has been probed by using three different model proteins which are remarkably different concerning molecular weight, size, and zeta potential (bovine serum albumin (BSA), lysozyme, and immunoglobulin G (IgG)). Indeed, the adsorption of the most abundant plasma protein (herein modeled as BSA) is circumvented even by using very short PGL shells due to the highly negative zeta potential of the produced assemblies which presumably promote protein–nanoparticle electrostatic repulsion. The negative zeta potential, on the other hand, enables lysozyme adsorption, and the phenomenon is governed by electrostatic forces as evidenced by isothermal titration calorimetry. Nevertheless, the protein coating can be circumvented by slightly increasing the degree of polymerization of the hydrophilic segment. Notably, the PGL length required to circumvent protein fouling is significantly smaller than the one required for PEO. This feature and the safety concerns regarding the synthetic procedures on the preparation of poly(ethylene oxide)-based amphiphilic copolymers might make polyglycidol a promising alternative toward the production of nonfouling spherical particles.
    Tags: POLE 4, POLYMERES.
    Attachment Full Text PDF 4.1 Mb (source)

  • J. Du, X. Li, S. Ruan, Y. Li, F. Ren, Y. Cao, X. Wang, Y. Zhang, S. Wu, and J. Li, “Rational design of a novel turn-on fluorescent probe for the detection and bioimaging of hydrazine with barbituric acid as a recognition group”, The Analyst, vol. 145, no. 2, p. 636-642, 2020.
    Abstract: A novel turn-on fluorescent probe with barbituric acid as a unique recognition group has been rationally designed and synthesized using a facile method for detecting hydrazine. , A novel turn-on fluorescent probe with barbituric acid as a unique recognition group has been rationally designed and synthesized using a facile method for detecting hydrazine. The 5-((7-(dimethylamino)-4,5-dihydronaphtho [1,2- b ] thiophen-2-yl)methylene)pyrimidine-2,4,6 (1 H ,3 H ,5 H )-trione ( DPT ) probe displays a large emission signal ratio variation (more than a 40-fold enhancement) in the presence of hydrazine under neutral conditions. Interestingly, a novel recognition mechanism based on a hydrazine-triggered addition–cyclisation-retro aldol was proposed and confirmed. Additionally, the DPT probe exhibits a low detection limit (5 × 10 −8 M), applicable to the physiological pH range (3–12), a broad linear response range for hydrazine concentrations between 0 and 34 μM and a large Stokes shift (147 nm) for hydrazine detection in aqueous solution. Moreover, the DPT probe was successfully implemented for hydrazine imaging in vivo .
    Tags: GOBS, POLE 3.

  • L. El Khoury, F. Célerse, L. Lagardère, L. - H. Jolly, E. Derat, Z. Hobaika, R. G. Maroun, P. Ren, S. Bouaziz, N. Gresh, and J. - P. Piquemal, “Reconciling NMR Structures of the HIV-1 Nucleocapsid Protein NCp7 Using Extensive Polarizable Force Field Free-Energy Simulations”, Journal of Chemical Theory and Computation, vol. 16, no. 4, p. 2013-2020, Apr. 2020.
    Abstract: Using polarizable (AMOEBA) and nonpolarizable (CHARMM) force fields, we compare the relative free energy stability of two extreme conformations of the HIV-1 nucleocapsid protein NCp7 that had been previously experimentally advocated to prevail in solution. Using accelerated sampling techniques, we show that they differ in stability by no more than 0.75–1.9 kcal/mol depending on the reference protein sequence. While the extended form appears to be the most probable structure, both forms should thus coexist in water explaining the differing NMR findings.
    Tags: MACO, POLE 1.
    Attachment Full Text PDF 1.7 Mb (source)

  • R. El-Hnayn, L. Canabady-Rochelle, C. Desmarets, L. Balan, H. Rinnert, O. Joubert, G. Medjahdi, H. Ben Ouada, and R. Schneider, “One-Step Synthesis of Diamine-Functionalized Graphene Quantum Dots from Graphene Oxide and Their Chelating and Antioxidant Activities”, Nanomaterials, vol. 10, no. 1, p. 104, Jan. 2020.
    Abstract: 2,2&rsquo;-(Ethylenedioxy)bis(ethylamine)-functionalized graphene quantum dots (GQDs) were prepared under mild conditions from graphene oxide (GO) via oxidative fragmentation. The as-prepared GQDs have an average diameter of ca. 4 nm, possess good colloidal stability, and emit strong green-yellow light with a photoluminescence (PL) quantum yield of 22% upon excitation at 375 nm. We also demonstrated that the GQDs exhibit high photostability and the PL intensity is poorly affected while tuning the pH from 1 to 8. Finally, GQDs can be used to chelate Fe(II) and Cu(II) cations, scavenge radicals, and reduce Fe(III) into Fe(II). These chelating and reducing properties that associate to the low cytotoxicity of GQDs show that these nanoparticles are of high interest as antioxidants for health applications.
    Tags: 2, 2’-(ethylenedioxy)bis(ethylamine), ARC, graphene quantum dots, optical properties, POLE 1, redox-active nanoparticles.
    Attachment Full Text PDF 3.9 Mb (source)

  • G. Falco, L. Simonin, S. Pensec, F. Dalmas, J. - M. Chenal, L. Bouteiller, and L. Chazeau, “Linear and nonlinear viscoelastic properties of segmented silicone-urea copolymers: Influence of the hard segment structure”, Polymer, vol. 186, p. 122041, Jan. 2020.
    Abstract: The linear and non-linear viscoelastic behaviors of 5 segmented silicone copolymers - with low fraction of 1,6-hexamethylene diisocyanate (HDI), 4,4′-methylenebis (cyclohexyl isocyanate) (HMDI), 1,3-bis(1-isocyanato-1-methylethyl)benzene (TMXDI), 2,4-tolylene diisocyanate (TDI) or isophorone diisocyanate (IPDI) as hard segments (HS) - are compared, in relation with their microstructure. When the HS are non-symmetrical, the materials nanostructuration is weak and has a limited impact on the mechanical response: two mechanical relaxations occur after the α relaxation of the polydimethylsiloxane (PDMS), the first related to the “unfreezing” of the HS-HS bonds, and the second one to the sticky reptation of the polymer chains. Conversely, when the HS are symmetrical, their self-organization is favored and the long range ordering of the HS is possible. The materials are then semi-crystalline like, with a low crystallinity (due to the low weight percentage of HS) and their flow, possible above their melting temperature (Tm), depends also on the HS dynamics, which is the most rapid for HDI.
    Tags: Mechanical relaxations, Nanostructure, POLE 4, POLYMERES, Segmented copolymers.

  • F. Foschi, C. Loro, R. Sala, J. Oble, L. Lo Presti, E. M. Beccalli, G. Poli, and G. Broggini, “Intramolecular Aminoazidation of Unactivated Terminal Alkenes by Palladium-Catalyzed Reactions with Hydrogen Peroxide as the Oxidant”, Organic Letters, vol. 22, no. 4, p. 1402-1406, Feb. 2020.
    Abstract: The palladium-catalyzed aminoazidation of aminoalkenes yielding azidomethyl-substituted nitrogen-containing heterocycles was developed. The procedure requires oxidative conditions and occurs at room temperature in the presence of hydrogen peroxide and NaN3 as the azide source. These conditions provide selective exo-cyclization/azidation of the carbon–carbon double bond, furnishing a versatile approach toward five-, six-, and seven-membered heterocyclic rings.
    Tags: POLE 1, ROCS.
    Attachment Full Text PDF 1.1 Mb (source)

  • A. Generosi, M. Guaragno, Q. Zhu, A. Proust, N. T. Barrett, L. Tortech, and B. Paci, “In-Situ Energy Dispersive X-ray Reflectivity Applied to Polyoxometalate Films: An Approach to Morphology and Interface Stability Issues in Organic Photovoltaics”, Symmetry, vol. 12, no. 8, p. 1240, Feb. 2020.
    Abstract: Organic solar cells, characterized by a symmetrical regular layered structure, are very promising systems for developing green, low cost, and flexible solar energy conversion devices. Despite the efficiencies being appealing (over 17%), the technological transfer is still limited by the low durability. Several processes, in bulk and at interface, are responsible. The quick downgrading of the performance is due to a combination of physical and chemical degradations. These phenomena induce instability and a drop of performance in working conditions. Close monitoring of these processes is mandatory to understand the degradation pathways upon device operation. Here, an unconventional approach based on Energy Dispersive X-ray Reflectivity (ED-XRR) performed in-situ is used to address the role of Wells–Dawson polyoxometalate (K6-P2W18O62, hereafter K6-P2W18) as hole transporting layer in organic photovoltaics. The results demonstrate that K6-P2W18 thin films, showing ideal bulk and interface properties and superior optical/morphological stability upon prolonged illumination, are attractive candidates for the interface of durable OPV devices.
    Tags: E-POM, in-situ X-ray characterization, organic photovoltaics, POLE 2, polyoxymetalate functional materials, thin films structure and morphology, time resolved EDXR.
    Attachment Snapshot 604.1 kb (source)
    Attachment Full Text PDF 3.9 Mb (source)
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