Publications by authors named "Didier Villemin"

This study aimed to evaluate the anti-inflammatory and analgesic properties of the methanolic extract of L. in small animal (rats and mice model). The current treatment for febrile conditions often involves the use of non-steroidal anti-inflammatory drugs (NSAIDs), which can have adverse effects, particularly gastrointestinal ulcers.

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The synthesis of a novel class of compounds bearing a coumarin entity was targeted. They are either iminocoumarins or characterized by the presence of a pyridone ring fused within the iminocoumarin scaffold. The targeted compounds were synthesized through a short method, thanks to microwave activation.

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In the present work, four branched methylated, 1,2-dimethyl-3-isopropyl-imidazolium (i-[CDmim]) and protonated,1-methyl-3-isopropyl-imidazolium (i-[Cmim])-based ionic liquids (ILs) with varying anion (Br, BF, PF, and NTf) were synthesized and investigated by NMR, infrared (IR) and Raman spectroscopy. Based on infrared and Raman spectroscopy, complete vibrational assignments have been performed. The IR and Raman analysis revealed that the vibrational spectra are virtually unaffected upon methylation, while significant frequency changes were observed by changing anion.

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Forming complexes with cyclodextrins can protect nicotinic acid (vitamin B3) from premature metabolism and enhance the solubility and stability of this drug. In this work, the formation of the inclusion complex of the neutral form of nicotinic acid and β-cyclodextrin was achieved. The complex is modeled using PM3, PM6-D4H3, and PM7, by considering two orientations of the guest: A and B, one is from wide to narrow rim, and the second is from narrow to the wide rim, respectively.

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Four ionic liquids (ILs) based on the bis(trifluoromethanesulfonyl)imide (NTf) anion were synthesized and characterized concerning their thermal stability, the occurrence of low temperature phase transitions and their volatility. All these physical quantities are highly important for possible applications. Both monocationic and dicationic ILs were considered.

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The outbreak of the SARS-CoV-2 virus in late 2019 and the spread of the COVID-19 pandemic have caused severe health and socioeconomic damage worldwide. Despite the significant research effort to develop vaccines, antiviral treatments, and repurposed therapeutics to effectively contain the catastrophe, there are no available effective vaccines or antiviral drugs that can limit the threat of the disease, so the infections continue to expand. To date, the search for effective treatment remains a global challenge.

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Hepatitis C virus (HCV) is a serious disease that threatens human health. Despite consistent efforts to inhibit the virus, it has infected more than 58 million people, with 300,000 deaths per year. The HCV nonstructural protein NS5A plays a critical role in the viral life cycle, as it is a major contributor to the viral replication and assembly processes.

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The COVID-19 has been creating a global crisis, causing countless deaths and unbearable panic. Despite the progress made in the development of the vaccine, there is an urge need for the discovery of antivirals that may better work at different stages of SARS-CoV-2 reproduction. The main protease (M) of the SARS-CoV-2 is a crucial therapeutic target due to its critical function in virus replication.

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The hepatitis C virus is a communicable disease that gradually harms the liver leading to cirrhosis and hepatocellular carcinoma. Important therapeutic interventions have been reached since the discovery of the disease. However, its resurgence urges the need for new approaches against this malady.

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Quantitative Structure Activity Relationships (QSAR or SAR) have helped scientists to establish mathematical relationships between molecular structures and their biological activities. In the present article, SAR studies have been carried out on 89 tetrahydroimidazo[4,5,1-jk][1,4]benzodiazepine (TIBO) derivatives using different classifiers, such as support vector machines, artificial neural networks, random forests, and decision trees. The goal is to propose classification models that will be able to classify TIBO compounds into two groups: high and low inhibitors of HIV-1 reverse transcriptase.

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Motivated by the role of copper ions in biological processes the aim of this study was to elucidate the impact of copper ions bound to hydroxyapatite on L-serine (L-Ser) and O-phospho-L-serine (O-Ph-L-Ser) adsorption at different acidity of aqueous solutions. The adsorption phenomenon was studied by FTIR, UV, and AA spectroscopy, XRD and thermal analysis methods together with the evolved gases analysis taking into consideration the ionic state of the amino acids as well as the apatite surface state, which are tightly correlated with the solution pH. In acidic solution, the main process involves apatite dissolution releasing calcium and copper ions.

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Mono-, di-, tri-, and tetraarylated thieno[3,2-b]thiophenes were synthesized by direct site-selective Pd-catalyzed C-H activation reactions with various aryl bromides in the presence of a phosphine-free Pd(OAc) /KOAc catalyst system in N,N-dimethylacetamide (DMAc). The arylation of 2-arylthieno[3,2-b]thiophene took place at the C3 position if the 2-aryl substituents possessed electron-withdrawing groups and at the C5 position if they were bulky and possessed electron-donating groups.

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Wastewater cleaning strategies based on the adsorption of materials are being increasingly considered, but the wide variety of organic pollutants at low concentrations still makes their removal a challenge. The hybrid material proposed here consists of a zwitterionic polyethylenimine polymer coating a magnetic core. Polyethylenimine is phosphonated at different percentages by a one-step process and used to coat maghemite nanoparticles.

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The synthesis of new unsymmetrically benzene-fused bis (tetrathiafulvalene) has been carried out by a cross-coupling reaction of the respective 4,5-dialkyl-1,3-dithiole-2-selenone 6-9 with 2-(4-(p-nitrophenyl)-1,3-dithiole-2-ylidene)-1,3,5,7-tetrathia-s-indacene-6-one 5 prepared by olefination of 4-(p-nitrophenyl)-1,3-dithiole-2-selenone 3 and 1,3,5,7-tetrathia-s-indacene-2,6-dione 4. The conversion of the nitro moiety 10a-d to amino 11a-d then dibenzylamine 12a-d groups respectively used reduction and alkylation methods. The electron donor ability of these new compounds has been measured by cyclic voltammetry (CV) technique.

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Two new families of divalent metal hybrid derivatives from the aromatic tetraphosphonic acids 1,4- and 1,3-bis(aminomethyl)benzene-N,N'-bis(methylenephosphonic acid), (H2O3PCH2)2-N-CH2C6H4CH2-N(CH2PO3H2)2 (designated herein as p-H8L and m-H8L) have been synthesized by crystallization at room temperature and hydrothermal conditions. The crystal structures of M[(HO3PCH2)2N(H)CH2C6H4CH2N(H)(CH2PO3H)2(H2O)2]·2H2O (M = Mg, Co, and Zn), M-(p-H6L), and M[(HO3PCH2)2N(H)CH2C6H4CH2N(H)(CH2PO3H)2]·nH2O (M = Ca, Mg, Co, and Zn and n = 1-1.5), M-(m-H6L), were solved ab initio by synchrotron powder diffraction data using the direct methods and subsequently refined using the Rietveld method.

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The synthesis and properties of a series of bis-tetrathiafulvalenes (bis-TTFs) containing nitrophenyl, aminophenyl or dimethylaminophenyl is reported. The synthesis was carried out by using routes involving Wittig-type, cross-coupling, reduction and alkylation reactions. The electron donor ability of these new compounds has been measured by cyclic voltammetry (CV).

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Multifunctional materials, especially those combining two or more properties of interest, are attracting immense attention due to their potential applications. MOFs, metal organic frameworks, can be regarded as multifunctional materials if they show another useful property in addition to the adsorption behavior. Here, we report a new multifunctional light hybrid, MgH(6)ODTMP·2H(2)O(DMF)(0.

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The Friedel-Crafts reaction of (η(4)-tetraphenylcyclobutadiene)(η(5)-carbomethoxycyclopentadienyl)cobalt with acid chlorides/aluminum chloride resulted exclusively in para-phenyl acylation. Both monoacylated (1.1 equiv of RCOCl/AlCl(3)) and tetraacylated products (>4 equiv of RCOCl/AlCl(3)) were synthesized.

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The enantiomeric purity determination of a synthetic intermediate of new 3,4-dihydro-2,2-dimethyl-2H-1-benzopyrans, i.e. 4-amino-2,2-dimethyl-6-ethoxycarbonylamino-3,4-dihydro-2H-1-benzopyran, was successfully carried out using an anionic cyclodextrin (CD) derivative combined with a chiral ionic liquid (IL).

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Article Synopsis
  • The study explores the effectiveness of tetrahydroimidazo[4,5,1-jk][1,4]benzodiazepinone (TIBO) derivatives as non-nucleoside reverse transcriptase inhibitors for HIV treatment.
  • The researchers utilized support vector machines (SVM) to assess the anti-HIV activity of 82 TIBO compounds based on four molecular descriptors, yielding better statistical results than other methods like multiple linear regression.
  • The analysis highlighted the significance of the hydrophobic parameter in understanding structure-activity relationships, allowing for the prediction of anti-HIV properties using only four directly calculable molecular descriptors.
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Herein, we describe an original novel method which allows the decontamination of the chromium-containing leather wastes to simplify the recovery of its considerable protein fractions. Organic salts and acids such as potassium oxalate, potassium tartrate, acetic and citric acids were tested for their efficiency to separate the chromium from the leather waste. Our investigation is based on the research of the total reversibility of the tanning process, in order to decontaminate the waste without its previous degradation or digestion.

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Ethane-1,1,2-trisphosphonic acid crystallizes as a hemihydrate, C(2)H(9)O(9)P(3).0.5H(2)O, in which the water O atom lies on an inversion centre in the space group P2(1)/c.

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Article Synopsis
  • Growing interest in ionic liquids (ILs) in analytical chemistry, particularly for separations, has led to the synthesis of chiral ILs for evaluating enantiomeric separations.
  • The study focused on the evaluation of two chiral ILs (ethyl- and phenylcholine of bis(trifluoromethylsulfonyl)imide) using capillary electrophoresis (CE) with anti-inflammatory drugs as model compounds.
  • Although these chiral ILs did not show direct enantioselectivity on their own, they improved separation selectivity and resolution when combined with traditional chiral selectors like cyclodextrin, hinting at potential synergistic effects.
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Structure-anti HIV activity relationships were established for a sample of 80 1-[2-hydroxyethoxy-methyl]-6-(phenylthio)thymine (HEPT) using a three-layer neural network (NN). Eight structural descriptors and physicochemical variables were used to characterize the HEPT derivatives under study. The network's architecture and parameters were optimized in order to obtain good results.

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A nonlinear quantitative structure-anti-HIV-1-activity relationship (QSAR) study was investigated in a series of 1-[2-hydroxyethoxy-methyl]-6-(phenylthio) thymine] (HEPT) derivatives acting as nonnucleoside reverse transcriptase inhibitors (NNRTIs). This QSAR study has been undertaken by a three-layered neural network (NN) using molecular descriptors known to be responsible for the anti-HIV-1 activity. The usefulness of the model and the nonlinearity of the relationship between molecular descriptors and anti-HIV-1 activity have been clearly demonstrated.

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