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

Rôle et mécanisme d'action de 2 cytokines pro-inflammatoires, interleukine-1B et interleukine-17, dans la dégénérescence du cartilage au cours des arthropathies

NANCY1-SCD Medecine (545472101) / SudocSudocFranceF

Cross Talk between IRAK4 and the NADPH Oxidase.

Abstract The ability of human neutrophils to combat bacterial and fungal infections depends on their production of reactive oxygen species. The enzymatic complex NADPH oxidase which is responsible for the generation of superoxide anion, is essential for the microbicidal activity of neutrophils, since patients with chronic granulomatous disease, whose NADPH oxidase is inactive, suffer recurrent infections. The exposure of neutrophils to lipopolysaccharide (LPS) amplifies their oxidative response to formylated-peptides (priming). However, the relationship between the signaling downstream of the toll-like receptor 4 after LPS stimulation and the activation of the oxidase has not been elucidated. The phosphorylation of the NADPH oxidase cytosolic factor p47phox is an essential step during the oxidase activation. Here, we test the hypothesis that Interleukin-1 receptor-associated kinase-4 (IRAK4) regulates the NADPH oxidase through phosphorylation of p47phox. We first show that p47phox is a substrate for IRAK4. We showed that IRAK4-phosphorylated p47phox could be subsequently phosphorylated by PKC suggesting that they phosphorylate p47phox at different residues. IRAK4 phosphorylated p47phox to a similar extent as PKC, however, while p47phox was phosphorylated by PKC only in serines, IRAK4 phosphorylated p47phox also in threonines as determined by two-dimensional electrophoresis. Importantly, IRAK4-phosphorylated p47phox activated the NADPH oxidase in a cell-free system (significantly different from the unphosphorylated control, p&amp;lt;0.05). Furthermore, cophosphorylation of p47phox by IRAK4 and PKC significantly potentiated the activity of the NADPH oxidase when compared to PKC phosphorylation alone (p&amp;lt;0.01). Finally, we identified, by mass spectrometry, the residues in p47phox that are targets for IRAK4 phosphorylation. We found that IRAK4 phosphorylates p47phox at a threonine rich domain which possibly constitutes a novel regulatory domain.</jats:p

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

Conversion of Meso-Aryl Substituted Open-Chain Pentapyrroles to Sapphyrins: Synthesis and Electrochemistry

Sapphyrin is a 22-π aromatic pentapyrrolic macrocycle containing one direct link and four bridging methine groups between five pyrrole subunits.1 This macrocycle is an early member of the group of “expanded porphyrins” and was obtained from a pentapyrrole, a byproduct in the synthesis of corroles. A series of open-chain pentapyrroles and sapphyrins with meso-tetraaryl groups were synthesized (Figure 1) and are characterized as to their electrochemistry and protonation reactions in nonaqueous media.2 The protonation-initiated conversion of pentapyrroles to sapphyrins upon oxidation was investigated and cyclic voltammetry was used to measure the redox potentials in CH2Cl2, PhCN, and/or pyridine (Py). REFERENCES 1. V. J. Bauer, D. L. J. Clive, D. Dolphin, J. B. Paine, F. L. Harris, M. M. King, J. Loder, S. W. C. Wang, R. B. Woodward, J. Am. Chem. Soc. 1983, 105,6429-6436. 2. W. Shan, N. Desbois, V. Blondeau-Patissier, M. L. Naitana, V. Quesneau, C. P. Gros, Y. Rousselin, W. Huang, Z. Ou, K. M. Kadish, Chem. Eur. J., 2017 , 23, 12833-12844. Figure 1 Figure 1 <jats:p /

Convenient Synthesis of Heterocyclic Compounds with Dihydropyrano[3,4-<i>b</i>]pyridine Scaffold

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