Here’s looking at the reduction of noninnocent copper corroles via anion induced electron transfer

The synthesis, electrochemical and spectroscopic characterization of five copper triarylcorroles bearing one, two or three meso-nitroaryl substituents is reported. Redox potentials and spectroscopic properties of the neutral Cu(II) corrole cation radicals and singly reduced form of the complexes are reported in $\mathrm{CH}_{2}\mathrm{Cl}_{2}$ and the ability of the initial noninnocent derivatives to be chemically reduced via anion induced electron transfer (AIET) is explored using cyanide ($\mathrm{CN}^{-}$) or fluoride ($\mathrm{F}^{-}$) anions in the form of tetra-$n$-butylammonium salts. UV–visible spectra of the singly reduced corroles and the species generated after addition of $\mathrm{CN}^{-}$ or $\mathrm{F}^{-}$ to solutions of the neutral compounds are identical, thus confirming the AIET event in these systems. This result, when combined with the facile electrochemical reduction, provides strong indirect evidence for the presence of noninnocence in these systems

In vitro nuclear interactome of the HIV-1 Tat protein

<p>Abstract</p> <p>Background</p> <p>One facet of the complexity underlying the biology of HIV-1 resides not only in its limited number of viral proteins, but in the extensive repertoire of cellular proteins they interact with and their higher-order assembly. HIV-1 encodes the regulatory protein Tat (86–101aa), which is essential for HIV-1 replication and primarily orchestrates HIV-1 provirus transcriptional regulation. Previous studies have demonstrated that Tat function is highly dependent on specific interactions with a range of cellular proteins. However they can only partially account for the intricate molecular mechanisms underlying the dynamics of proviral gene expression. To obtain a comprehensive nuclear interaction map of Tat in T-cells, we have designed a proteomic strategy based on affinity chromatography coupled with mass spectrometry.</p> <p>Results</p> <p>Our approach resulted in the identification of a total of 183 candidates as Tat nuclear partners, 90% of which have not been previously characterised. Subsequently we applied <it>in silico </it>analysis, to validate and characterise our dataset which revealed that the Tat nuclear interactome exhibits unique signature(s). First, motif composition analysis highlighted that our dataset is enriched for domains mediating protein, RNA and DNA interactions, and helicase and ATPase activities. Secondly, functional classification and network reconstruction clearly depicted Tat as a polyvalent protein adaptor and positioned Tat at the nexus of a densely interconnected interaction network involved in a range of biological processes which included gene expression regulation, RNA biogenesis, chromatin structure, chromosome organisation, DNA replication and nuclear architecture.</p> <p>Conclusion</p> <p>We have completed the <it>in vitro </it>Tat nuclear interactome and have highlighted its modular network properties and particularly those involved in the coordination of gene expression by Tat. Ultimately, the highly specialised set of molecular interactions identified will provide a framework to further advance our understanding of the mechanisms of HIV-1 proviral gene silencing and activation.</p

Concept, synthèse et mécanisme d'action de motifs hétéroaromatiques à visée radiochimiothérapeutique interne du mélanome

Le risque de développer un mélanome augmente fortement d'année en année. A partir de cette constatation, notre travail a consisté à la synthèse de molécules pouvant être utilisées en radiochimiothérapie interne du mélanome. Notre recherche s'est d'abord articulée sur une bibliographie récente montrant que des structures de type iodobenzamides ont été développées dans une finalité de radiothérapie. Une pharmacomudulation par substitution du noyau benzènique par un hétérocycle a été envisage e. Deux stratégies ont été réalisées soit à partir d'hétérocycles originaux soit à partir d'un motif acridine (ou acridone) reconnu comme cytotoxique. La 1ère approche a mis en jeu divers polyhétérocycles obtenus par réaction de Friedländer sur le synthon imidazopyridinique. Une évaluation de la cytotoxicité puis des études RMN d'intercalation avec un oligonucléotide de synthèse ont été effectuées. La seconde approche s'est principalement orientée vers la synthèse de iodoacridines et acridones carboxamides analogues du DACA et de l'amsacrine. Une détermination des valeurs d'IC50 de ces composés a été entreprise afin d'évaluer leur cytotoxicité vis-à vis du mélanome. Cette recherche, réalisée au sein de l'UMR INSERM 484 et à l'interface chimie-biologie, sera prolongée par des études de biodistribution.Malignant melanoma has become a serious public health problem in most countries due to its dramatic rise in incidence and mortality. The aim of this work is to conceive new structures that could be used in an internal chemo radionuclide therapy. It was previously reported a series of iodobenzamide derivatives that showed affinity for melanoma tissue. So, we decided the remplacement of the phenyl moiety by a cytotoxic heterocyclic nucleus. Two approaches have been developed. The first one consisted in the synthesis of original polyheterocycles using Friedländer's reaction in imidazo[1,2-a]pyridine serie. We tested their biological effects in vitro on cell lines. In order to test the intercalating properties of these compounds, their interactions with a synthetic oligodeoxynucleotide were studied by NMR spectroscopy. A second approach consisted in using an heterocyclic nucleus known as being cytotoxic : the acridine (or the acridone). Various molecules, structural analogs of two anti-cancer agents : the amsacrine and the DACA, including the functionalities N-[2-(diethylamino)ethyl]carboxamide and iodine have been synthesized. IC50 values showed cytotoxic effects toward melanoma cells. A study of tissue distribution would be effected to completed this work.CLERMONT FD-BCIU-Santé (631132104) / SudocPARIS-BIUP (751062107) / SudocSudocFranceF

Porous materials applied to biomarker sensing in exhaled breath for monitoring and detecting non-invasive pathologies

International audienceOverview of the use of porous materials for gas sensing to analyze the exhaled breath of patients for disease identification.The quantification of specific gases among thousand of VOCs (Volatile Organic Compounds) present in the human breath at the ppm/ppb level can be used to evidence the presence of diseases in the human body. The detection of these biomarkers in human exhaled breath through a noninvasive approach is an important field of research which is still attracting important attention to this day. A portable device working at room temperature and usable directly on exhaled breath samples is still a challenge requiring a sensing material with high performances. The rich composition of the human breath implies that the sensing material must be highly selective and sensitive (ppm/ppb) in high relative humidity (RH) conditions and preferably at room temperature. The present work intends to provide a review on recent works in this application field through the use of porous materials and discuss the interest of Metal Organic Frameworks (MOFs) for such application. MOFs are highly porous crystalline materials often used for gas detection and capture, thus raising the question of their potential for detection in exhaled breath

Le développement durable à l'épreuve des TIC

Such as Janus, the ancient Roman god who presided over all beginnings and all transitions, information technologies now have the privilege of accompanying any new technical invention. Faced with the increasing risk of climate change, the concept of sustainable development appears to be unanimously accepted by political and economic authorities. When pressed to put forward new strategies to be implemented, many of them declare : “Thanks to green growth supported by modern information and communication technologies”. Terminal has made a survey of what now appears to be obvious ; this special issue addresses the role of information technology applied to sustainable development with three questions : “green information technology”, “environment information and awareness”, “a toolkit for sustainable development”. Be they researchers, engineers, medical practicians or academics, the authors of the papers in this issue all make a contribution to the necessary assessment of the use of information technology in every aspect of sustainable development in an attempt to answer this question: is another world still possible?Tel Janus, cette divinité romaine présidant aux commencements et aux passages, les technologies de l’information ont désormais le privilège d’accompagner l’ensemble des innovations et mutations du système technicien. Face aux risques climatiques qui se précisent, la notion de développement durable semble faire l’unanimité des responsables politiques et économiques. Pressés de présenter les stratégies à mettre en oeuvre, certains affirment : « Grâce à une croissance verte soutenue par les nouvelles technologies de l'information et de la communication ». Terminal a voulu analyser ce qui devient une évidence et livre aujourd’hui un numéro spécial s’interrogeant sur le rôle joué par les technologies de l’information au service du développement durable. Qu'ils soient chercheurs, ingénieurs, médecins ou universitaires, les auteurs de ce numéro articulé autour de trois questionnements distincts (« Des TIC vertes ? », « Informations et consciences environnementales ?», « Un outil pour le développement durable ? ») contribuent à la nécessaire évaluation des NTIC dans chacune des dimensions du développement durable pour tenter de répondre à cette question : un autre monde est-il encore possible

Le développement durable à l’épreuve des TIC

Le nouveau dossier de Terminal est consacré aux relations entre technologies de l’information et de la communication (TIC) et développement durable. Il interroge la capacité des TIC à s’insérer et, pourquoi pas, à accompagner la transformation de nos sociétés vers des modèles socialement plus justes et écologiquement plus respectueux des écosystèmes naturels. Le principal défi posé par un tel objectif réside dans le dépassement des oppositions entre quatre dimensions structurantes du fonction..

Easy access to heterobimetallic complexes for medical imaging applications via microwave-enhanced cycloaddition

The Cu(I)-catalysed Huisgen cycloaddition, known as “click” reaction, has been applied to the synthesis of a range of triazole-linked porphyrin/corrole to DOTA/NOTA derivatives. Microwave irradiation significantly accelerates the reaction. The synthesis of heterobimetallic complexes was easily achieved in up to 60% isolated yield. Heterobimetallic complexes were easily prepared as potential MRI/PET (SPECT) bimodal contrast agents incorporating one metal (Mn, Gd) for the enhancement of contrast for MRI applications and one “cold” metal (Cu, Ga, In) for future radionuclear imaging applications. Preliminary relaxivity measurements showed that the reported complexes are promising contrast agents (CA) in MRI

Porphyrin Antenna-Enriched BODIPY–Thiophene Copolymer for Efficient Solar Cells

International audienceLow bandgap A−π–D copolymer, P(BdP-DEHT), consisting of alternating BOronDIPYrromethene (BODIPY) and thiophene units bridged by ethynyl linkers, and its porphyrin-enriched analogue, P(BdP/Por-DEHT), were prepared, and their optical and electrochemical properties were studied. P(BdP-DEHT) exhibits strong absorption in the 500–800 nm range with an optical bandgap of 1.74 eV. On the basis of cyclic voltammetry, the highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) energy levels are evaluated to be −5.40 and −3.66 eV, respectively. After the anchoring of zinc(II) porphyrin on the BODIPY unit, P(BdP/Por-DEHT) displays broadened absorption, thanks to porphyrins, and the optical bandgap decreases to 1.59 eV because of extension of BODIPY conjugation. The resulting estimated HOMO and LUMO energy levels, respectively, move to −5.32 and −3.73 eV. After optimization of the P(BdP-DEHT) or P(BdP/Por-DEHT) to PC71BM weight ratio to 1:2 in dichlorobenzene solution, the bulk heterojunction polymer solar cells show overall power conversion efficiencies (PCEs) of 3.03 and 3.86%, respectively. After solvent vapor annealing (SVA) treatment in CH2Cl2 for 40 s, the PCEs increased to 7.40% [Voc of 0.95 V, Jsc of 12.77 mA/cm2, and fill factor (FF) of 0.61 with energy loss of 0.79 eV] and 8.79% (Voc of 0.92 V, Jsc of 14.48 mA/cm2, and FF of 0.66 with energy loss of 0.67 eV). The increase in the PCE for P(BdP/Por-DEHT)-based devices is mainly attributed to the enhancement in Jsc and FF, which may be related to the broader absorption spectra, lower band gap, and better charge transport of P(BdP/Por-DEHT) compared to P(BdP-DEHT). This could also be related to the optimized nanoscale morphology of the active layer for both efficient exciton dissociation and charge transport toward the electrodes and a balanced charge transport in the device, induced by the SVA treatment of the active layer