The Bioactive Phenolic Agents Diaryl Ether CVB2-61 and Diarylheptanoid CVB4-57 as Connexin Hemichannel Blockers

Inflammation mediators enhance the activity of connexin (Cx) hemichannels, especially in the epithelial and endothelial tissues. As potential release routes for injury signals, such as (oligo)nucleotides, Cx hemichannels may contribute to long-lasting inflammation. Specific inhibition of Cx hemichannels may therefore be a mode of prevention and treatment of long-lasting, chronic sterile inflammation. The activity of Cx hemichannels was analysed in N2A and HeLa cells transfected with human Cx26 and Cx46 as well as in Calu-3 cells, using dye uptake as functional assay. Moreover, the possible impacts of the bioactive phenolic agents CVB2-61 and CVB4-57 on the barrier function of epithelial cells was analysed using Calu-3 cells. Both agents inhibited the dye uptake in N2A cells expressing Cx26 (>5 µM) and Cx46 (>20 µM). In Calu-3 cells, CVB2-61 and CVB4-57 reversibly inhibited the dye uptake at concentrations as low as 5 µM, without affecting the gap junction communication and barrier function, even at concentrations of 20 µM. While CVB2-61 or CVB4-57 maintained a reduced dye uptake in Calu-3 cells, an enhancement of the dye uptake in response to the stimulation of adenosine signalling was still observed after removal of the agents. The report shows that CVB2-61 and CVB4-57 reversibly block Cx hemichannels. Deciphering the mechanisms of the interactions of these agents with Cx hemichannels could allow further development of phenolic compounds to target Cx hemichannels for better and safer treatment of pathologies that involve Cx hemichannels

New access to chiral pyrrolidine and piperidine β-enamino ketones. Application to the enantioselective synthesis of (–)-hygroline

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Isodicyclopentadienes and related molecules. Part 41. Stereochemical course of Diels-Alder cycloadditions to (hydroxymethyl)-substituted plane-nonsymmetric cyclopentadienes

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A Photoyellowing Simulation of Bleached High Yield Wood Pulp by Lignin Models Included in a Solid Carbohydrate Matrix

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Photochemical Degradation of Lignin through α C—O Bond Cleavage of Non Phenolic Benzyl Aryl Ether Units. A Study of the Photochemistry of a(2',4',6'-Trimethyl-Phenoxy)-3,4 Dimethoxy Toluene

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Stereoselective access to trans-2,5-disubstituted pyrrolidine derivatives by nucleophilic addition to bicyclic N-Acyliminium ion

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Anti-inflammatory Activity of Naturally Occuring Diarylheptanoids - A Review

International audienceInflammation involving the innate and adaptive immune systems is a normal response to infection. However, if it becomes uncontrolled, inflammation may result in autoimmune or auto inflammatory disorders, neurodegenerative diseases or cancers. The currently available anti-inflammatory drug therapy is often not successful or induces severe side effects. Thus, the search of new therapeutic options for the treatment of inflammation is highly required. Medicinal plants have been an interesting source for obtaining new active compounds. Diarylheptanoids characterized by a 1, 7-diphenylheptane structural skeleton, are a class of secondary plant metabolites that have gained increasing interest over the last few decades due to a wide variety of biological activities. This review covers 182 natural linear or macrocyclic diarylheptanoids described in the period of 1982 to 2020 with anti-inflammatory activities evaluated using quantified in vitro and/or in vivo assays. All of these data highlight the pharmacological potential of these natural compounds to act as anti-inflammatory drugs

Consequences of twofold bridging of the [10]annulene system as in cis-10,11-dihydrodicyclopenta[cd,gh]pentalene

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Recent Trends in the Design, Synthesis, Spectroscopic Behavior, and Applications of Benzazole-Based Molecules with Solid-State Luminescence Enhancement Properties

International audienceMolecules that exhibit solid-state luminescence enhancement, i.e. the rare property to be more strongly emissive in the solid state than in solution, find an increasing number of applications in the fields of optoelectronic and nanophotonic devices, sensors, security papers, imaging and theranostics. Benzazole (BZ) heterocycles are of particular value in this context. The simple enlargement of their πelectron system using a-C=C-Ar, or-N=C-Ar moiety is enough for intrinsic SLE properties to appear. Their association with a variety of polyaromatic motifs leads to SLE-active molecules that frequently display attractive electroluminescent properties and are sensitive to mechanical stimuli. The excitedstate intramolecular proton transfer (ESIPT) process that takes place in some hydroxy derivatives reinforces the SLE effect and allows the development of new sensors based on a protection/deprotection strategy. BZ may also be incorporated into frameworks that are prototypical aggregation-induced enhancement (AIE) luminogens, such as the popular tetraphenylethene (TPE), leading to materials with excellent optical and electroluminescent performance. This review encompasses the various ways to use benzazole units in SLE systems. It underlines the significant progresses recently made in the understanding of the photophysical mechanisms involved. A brief overview of the synthesis shows that BZ units are robust building blocks, easily incorporated into a variety of structures. Generally speaking, we try to show how advantage may be taken from these small heterocycles for the design of increasingly efficient luminescent materials