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Leuven, Belgium

Saudi M.,Rega Institute for Medical Research | Zmurko J.,Rega Institute for Medical Research | Kaptein S.,Rega Institute for Medical Research | Rozenski J.,Rega Institute for Medical Research | And 6 more authors.
European Journal of Medicinal Chemistry | Year: 2016

High-Throughput screening of a subset of the CD3 chemical library (Centre for Drug Design and Discovery; KU Leuven) provided us with a lead compound 1, displaying low micromolar potency against dengue virus and yellow fever virus. Within a project aimed at discovering new inhibitors of flaviviruses, substitution of its central imidazole ring led to synthesis of variably substituted pyrazine dicarboxylamides and phthalic diamides, which were evaluated in cell-based assays for cytotoxicity and antiviral activity against the dengue virus (DENV) and yellow fever virus (YFV). Fourteen compounds inhibited DENV replication (EC50 ranging between 0.5 and 3.4 1/4M), with compounds 6b and 6d being the most potent inhibitors (EC50 0.5 1/4M) with selectivity indices (SI) > 235. Compound 7a likewise exhibited anti-DENV activity with an EC50 of 0.5 1/4M and an SI of >235. In addition, good antiviral activity of seven compounds in the series was also noted against the YFV with EC50 values ranging between 0.4 and 3.3 1/4M, with compound 6n being the most potent for this series with an EC50 0.4 1/4M and a selectivity index of >34. Finally, reversal of one of the central amide bonds as in series 13 proved deleterious to the inhibitory activity. © 2016 The Authors. Source

Draoui N.,Institute Of Recherche Experimentale Et Clinique Irec | Draoui N.,Reactivity | Schicke O.,Reactivity | Fernandes A.,Reactivity | And 13 more authors.
Bioorganic and Medicinal Chemistry | Year: 2013

Under hypoxia, cancer cells consume glucose and release lactate at a high rate. Lactate was recently documented to be recaptured by oxygenated cancer cells to fuel the TCA cycle and thereby to support tumor growth. Monocarboxylate transporters (MCT) are the main lactate carriers and therefore represent potential therapeutic targets to limit cancer progression. In this study, we have developed and implemented a stepwise in vitro screening procedure on human cancer cells to identify new potent MCT inhibitors. Various 7-substituted carboxycoumarins and quinolinone derivatives were synthesized and pharmacologically evaluated. Most active compounds were obtained using a palladium-catalyzed Buchwald-Hartwig type coupling reaction, which proved to be a quick and efficient method to obtain aminocarboxycoumarin derivatives. Inhibition of lactate flux revealed that the most active compound 19 (IC 50 11 nM) was three log orders more active than the CHC reference compound. Comparison with warfarin, a conventional anticoagulant coumarin, further showed that compound 19 did not influence the prothrombin time which, together with a good in vitro ADME profile, supports the potential of this new family of compounds to act as anticancer drugs through inhibition of lactate flux. © 2013 Elsevier Ltd. All rights reserved. Source

Delattin N.,Catholic University of Leuven | De brucker K.,Catholic University of Leuven | Vandamme K.,Health Science University | Meert E.,Catholic University of Leuven | And 5 more authors.
Journal of Antimicrobial Chemotherapy | Year: 2014

Objectives: Biofilms of Candida species, often formed on medical devices, are generally resistant to currently available antifungal drugs. The aim of this study was to identify compounds that increase the activity of amphotericin B and caspofungin, commonly used antifungal agents, against Candida biofilms. Methods: A library containing off-patent drugs was screened for compounds, termed enhancers, that increase the in vitro activity of amphotericin B against Candida albicans biofilms. Biofilms were grown in 96-well plates and growth was determined by the cell titre blue assay. Synergy between identified enhancers and antifungal agents was further characterized in vitro using fractional inhibitory concentration index (FICI) values and in vivo using a worm biofilm infection model. In light of the application of these enhancers onto implants, their possible effect on the growth potential of MG63 osteoblast-like cells was assessed. Results: Pre-incubation of C. albicans biofilms with subinhibitory concentrations of the enhancers drospirenone, perhexiline maleate or toremifene citrate significantly increased the activity of amphotericin B or caspofungin (FICI < 0.5) against C. albicans and Candida glabrata biofilms. Moreover, these enhancers did not affect the growth potential of osteoblasts. Interestingly, toremifene citrate also enhanced the in vitro activity of caspofungin in a mixed biofilm consisting of C. albicans and Staphylococcus epidermidis. Furthermore, we demonstrate synergy between toremifene citrate and caspofungin in an in vivo worm C. albicans biofilm infection model. Conclusions: Our data demonstrate an in vitro and in vivo enhancement of the antibiofilm activity of caspofungin by toremifene citrate. Furthermore, our results pave the way for implant-related applications of the identified enhancers. © The Author 2013. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved. Source

Delattin N.,Catholic University of Leuven | Bardiot D.,CISTIM Leuven Vzw | Marchand A.,CISTIM Leuven Vzw | Chaltin P.,CISTIM Leuven Vzw | And 4 more authors.
Molecules | Year: 2012

We have identified two subseries of 2,6-disubstituted quinolines, consisting of 6-amide and 6-urea derivatives, which are characterized by fungicidal activity against Candida albicans with minimal fungicidal concentration (MFC) values < 15 μ M. The 6-amide derivatives displayed the highest fungicidal activity against C. albicans, in particular compounds 1, 5 and 6 characterized by MFC values of 6.25-12.5 μ M. Compounds 1 and 5 of this series displayed fungicidal activity against the emerging pathogen Candida glabrata (MFC < 50 μ M). The 6-amide derivatives 1, 2, 5, and 6 and the 6-urea derivatives 10, 12, 13 and 15 could also eradicate C. albicans biofilms. We found that the 6-urea derivatives 10, 13, and 15 induced accumulation of endogenous reactive oxygen species in Candida albicans biofilms. © 2012 by the authors; licensee MDPI, Basel, Switzerland. Source

Khan N.A.,Catholic University of Leuven | Willemarck N.,Catholic University of Leuven | Talebi A.,Catholic University of Leuven | Marchand A.,CISTIM Leuven Vzw | And 12 more authors.
Oncotarget | Year: 2016

The development of cancer is often accompanied by a loss of the primary cilium, a microtubule-based cellular protrusion that functions as a cellular antenna and that puts a break on cell proliferation. Hence, restoration of the primary cilium in cancer cells may represent a novel promising approach to attenuate tumor growth. Using a high content analysis-based approach we screened a library of clinically evaluated compounds and marketed drugs for their ability to restore primary cilium expression in pancreatic ductal cancer cells. A diverse set of 118 compounds stimulating cilium expression was identified. These included glucocorticoids, fibrates and other nuclear receptor modulators, neurotransmitter regulators, ion channel modulators, tyrosine kinase inhibitors, DNA gyrase/topoisomerase inhibitors, antibacterial compounds, protein inhibitors, microtubule modulators, and COX inhibitors. Certain compounds also dramatically affected the length of the cilium. For a selection of compounds (Clofibrate, Gefitinib, Sirolimus, Imexon and Dexamethasone) their ability to restore ciliogenesis was confirmed in a panel of human cancer cell line models representing different cancer types (pancreas, lung, kidney, breast). Most compounds attenuated cell proliferation, at least in part through induction of the primary cilium, as demonstrated by cilium removal using chloral hydrate. These findings reveal that several commonly used drugs restore ciliogenesis in cancer cells, and warrant further investigation of their antineoplastic properties. Source

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