Publications by authors named "Sylvain Rault"

The chemokine receptor CXCR4 and its ligand CXCL12 regulate leukocyte trafficking, homeostasis and functions and are potential therapeutic targets in many diseases such as HIV-1 infection and cancers. Here, we identified new CXCR4 ligands in the CERMN chemical library using a FRET-based high-throughput screening assay. These are bis-imidazoline compounds comprising two imidazole rings linked by an alkyl chain.

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Human malaria infection begins with a one-time asymptomatic liver stage followed by a cyclic symptomatic blood stage. For decades, the research for novel antimalarials focused on the high-throughput screening of molecules that only targeted the asexual blood stages. In a search for new effective compounds presenting a triple action against erythrocytic and liver stages in addition to the ability to block the transmission of the disease the mosquito vector, 2-amino-thienopyrimidinone derivatives were synthesized and tested for their antimalarial activity.

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3-(Alkyl(dialkyl)amino)benzothieno[2,3-f]quinazolin-1(2H)-ones (4-9) have been designed using Ellipticine structure as a model, replacing the carbazole core and the pyridine ring with a dibenzothiophene and a pyrimidine moiety, respectively. New benzothienoquinazolinones (4-9) have been synthesized by a simple one-pot reaction employing 3-aminodibenzothiophene as starting material. The benzothienoquinazolinones obtained (4-9), were evaluated for their anticancer activity against two breast cancer cell lines, MDA-MB-231 and MCF-7.

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Protein-protein interactions are attractive targets because they control numerous cellular processes. In oncology, apoptosis regulating Bcl-2 family proteins are of particular interest. Apoptotic cell death is controlled via PPIs between the anti-apoptotic proteins hydrophobic groove and the pro-apoptotic proteins BH3 domain.

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Mcl-1, which is an anti-apoptotic member of the Bcl-2 protein family, is overexpressed in various cancers and promotes the aberrant survival of tumor cells. To inhibit Mcl-1, and initiate apoptosis, an interaction between BH3-only proteins and Mcl-1 anti-apoptotic protein is necessary. These protein-protein interactions exhibit some selectivity: Mcl-1 binds specifically to Noxa, whereas Bim and Puma bind strongly to all anti-apoptotic proteins.

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Alzheimer's Disease (AD) is a neurodegenerative brain disorder in which many biological dysfunctions are involved. Among them, two main types of lesions were discovered and widely studied: the amyloid plaques and the neurofibrillary tangles (NFTs). These two lesions are caused by the dysfunction and the accumulation of two proteins which are, respectively, the beta-amyloid peptide and the tau protein.

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Natural or synthetic carbazole derivatives have recently attracted the attention of the scientific world because of their multiple biological activity, leading to an increase of designed, synthesized and studied analogues. In this paper, four 1,4-dimethylcarbazole derivatives, analogues of Ellipticine, have been investigated for their ability to block cancer cells growth, with low effects on the proliferation of normal cells. DNA topoisomerases inhibition assays, docking simulations, stability studies and effects on a membrane model are reported.

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In a search for new antifungal compounds, we screened a library of 4,454 chemicals for toxicity against the human fungal pathogen Aspergillus fumigatus. We identified sr7575, a molecule that inhibits growth of the evolutionary distant fungi A. fumigatus, Cryptococcus neoformans, Candida albicans, and Saccharomyces cerevisiae but lacks acute toxicity for mammalian cells.

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A series of unknown 3-(alkyl(dialkyl)amino)benzofuro[2,3-f]quinazolin-1(2H)-ones 4-17 has been synthesized as new ellipticine analogs, in which the carbazole moiety and the pyridine ring were replaced by a dibenzofuran residue and a pyrimidine ring, respectively. The synthesis of these benzofuroquinazolinones 4-17 was performed in a simple one-pot reaction using 3-aminodibenzofuran or its 2-methoxy derivative, as starting materials. From 3-(dipropylamino)-5-methoxybenzofuro[2,3-f] quinazolin-1(2H)-one (13), we prepared 3-(dipropylamino)-5-hydroxybenzofuro[2,3-f]quinazolin-1(2H)-one (18), referred to as DPA-HBFQ-1.

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An antileishmanial pharmacomodulation at position 4 of 8-nitroquinolin-2(1H)-one was conducted by using the Sonogashira and Suzuki-Miyaura coupling reactions. A series of 25 derivatives was tested in vitro on the promastigote stage of Leishmania donovani along with an in vitro cytotoxicity evaluation on the human HepG2 cell line. Only the derivatives bearing a phenyl moiety at position 4 of the quinoline ring displayed interesting biologic profile, when the phenyl moiety was substituted at the para position by a Br or Cl atom, or by a CF3 group.

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In response to the extensive use of antibiotics, bacteria have evolved numerous mechanisms of defense against antimicrobial agents. Among them, extrusion of the antimicrobial agents outside the bacterial cell through efflux pumps is a major cause of concern. At first limited to one or few structurally-related antibiotics, bacterial resistance have then progressed towards cross-resistance between different classes of antibiotics, leading to multidrug-resistant microorganisms.

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A preliminary in vitro screening of compounds belonging to various chemical families from our library revealed the thieno[3,2-d]pyrimidin-4(3H)-one scaffold displayed a promising profile against Plasmodium falciparum. Then, 120 new derivatives were synthesized and evaluated in vitro; compared to drug references, 40 showed good activity toward chloroquine sensitive (IC50 35-344 nM) and resistant (IC50 45-800 nM) P. falciparum strains.

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Estrogens control a wide number of aspects of human physiology and play a key role in multiple diseases, including cancer. Estrogens act by binding to and activating the cognate receptor (ER), however numerous studies have revealed that the G protein-coupled receptor named GPR30/GPER mediates also estrogen signals. As ER and GPER share the ability to bind to same compounds, the use of GPER-selective ligands has allowed a better understanding of the biological responses mediated by GPER.

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Cyclin-dependent kinases (CDKs) control many cellular processes and are considered important therapeutic targets. Large collections of inhibitors targeting CDK active sites have been discovered, but their use in chemical biology or drug development has been often hampered by their general lack of specificity. An alternative approach to develop more specific inhibitors is targeting protein interactions involving CDKs.

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Apoptosis control defects such as the deregulation of Bcl-2 family member expression are frequently involved in chemoresistance. In ovarian carcinoma, we previously demonstrated that Bcl-xL and Mcl-1 cooperate to protect cancer cells against apoptosis and their concomitant inhibition leads to massive apoptosis even in the absence of chemotherapy. Whereas Bcl-xL inhibitors are now available, Mcl-1 inhibition, required to sensitize cells to Bcl-xL-targeting strategies, remains problematic.

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From a recently identified antileishmanial pharmacophore, a structure-activity relationship study was conducted by introducing various aminated, phenoxy or thiophenoxy moieties at position 4 of the 8-nitroquinolin-2(1H)-one scaffold, using SNAr reactions. Thus a series of 47 derivatives was synthesized and evaluated in vitro on the promastigote stage of Leishmania donovani. In parallel, the cytotoxicity of the active molecules was tested on the human HepG2 cell line.

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Thanks to a preliminary in vitro screening of several CCl3-substituted-nitrogen containing heterocycles belonging to our chemical library, the 2-trichloromethylquinoxaline scaffold appeared to be of potential interest for developing new antiplasmodial agents. Then, combining these experimental results to the antimalarial properties reported for various pyrrolo[1,2-a]quinoxaline derivatives, an original series of fifteen 7-substituted-4-trichoromethylpyrrolo[1,2-a]quinoxalines was synthesized in a 4 to 5 reaction steps pathway. All molecules were evaluated in vitro toward both their antiplasmodial activity on the K1 multi-resistant Plasmodium falciparum strain and their cytotoxicity on the HepG2 human cell line.

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In recent years, preclinical and clinical studies have generated considerable interest in the development of histamine H3 receptor (H3R) antagonists as novel treatment for degenerative disorders associated with impaired cholinergic function. To identify novel scaffolds for H3R antagonism, a common feature-based pharmacophore model was developed and used to screen the 17,194 compounds of the CERMN (Centre d'Etudes et de Recherche sur le Médicament de Normandie) chemical library. Out of 268 virtual hits which have been gathered in 34 clusters, we were particularly interested in tricyclic derivatives also exhibiting a potent 5HT4R affinity.

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The pharmacokinetic properties of radiotracers are crucial for successful in vivo single-photon emission computed tomographic (SPECT) imaging. Our goal was to determine if MDR1A-deficient animals could allow better SPECT imaging outcomes than wild-type (WT) animals for a selection of serotoninergic radioligands. Thus, we compared the performances of 123I-p-MPPI, 123I-R91150, 123I-SB207710, and 123I-ADAM radioligands, for imaging of their respective targets (5-hydroxytryptamine [5-HT]1A, 5-HT2A, 5-HT4, and serotonin transporter [SERT]), in WT and Mdr1a knockout (KO) rats.

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Overexpression of efflux pumps is an important mechanism of bacterial resistance that results in the extrusion of antimicrobial agents outside the bacterial cell. Inhibition of such pumps appears to be a promising strategy that could restore the potency of existing antibiotics. The NorA efflux pump of Staphylococcus aureus confers resistance to a wide range of unrelated substrates, such as hydrophilic fluoroquinolones, leading to a multidrug-resistance phenotype.

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Several new alkylguanidines derived from carbazole have been synthesized in a simple one-pot reaction starting from 3-aminocarbazole derivatives. The aminocarbazoles were reacted with ethoxycarbonylisothiocyanate, to give thiourea intermediates, followed by the addition of an alkylamine and HgCl2 to give ethoxycarbonylguanidine intermediates. The reaction mixture was then heated at 160 °C to give the N-(1,4-dimethyl-9H-carbazol-3-yl)-N'-alkylguanidines.

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With the aim to find new protein-protein inhibitors, a three part methodology was applied to oligophenylpyridines. Theoretical ring twist angle predictions have been validated by X-ray diffraction and molecular dynamics simulations with NMR constraints. Careful choice of substituent and nitrogen positions in oligophenylpyridyl foldamer units opens the way to conformational control of the side chain distribution of this α-helix mimic.

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Nine new 17-(piperazin-1-yl)pyridin-5-yl)steroids as abiraterone analogues were synthesized. Compounds 5d and 5g showed selective activities against 17α-hydroxylase/C17,20-lyase (CYP17A1) and aromatase (CYP19), respectively. IC50 values of 5d were 5.

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Background: Our work has been carried out in the context of the therapeutic failure in ovarian carcinoma, which remains the leading cause of death by gynecologic malignancy. In these tumours, recurrence and subsequent acquired chemoresistance constitute major hurdles to successful therapy. Here we studied the interest of a member of the tripentone chemical family, MR22388, for the treatment of chemoresistant ovarian cancer cells.

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This work describes the study of the mechanism of action and spectrum of activity of MR22388, a novel anti-cancer agent belonging to the tripentone series. MR22388 is highly cytotoxic (within the nanomolar range) against numerous cancer cell lines and studies of its cytotoxicity mechanisms show that it is a weak inhibitor of the polymerization of tubulin and that it induces apoptosis via the MAP kinase pathways. Further MR22388 is a very strong inhibitor of several kinases including the tyrosine kinase FLT3-ITD.

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