Novel 8-nitroquinolin-2(1H)-ones as NTR-bioactivated antikinetoplastid molecules:Synthesis, electrochemical and SAR study

International audienceTo study the antiparasitic 8-nitroquinolin-2(1H)-one pharmacophore, a series of 31 derivatives was synthesized in 1-5 steps and evaluated in vitro against both Leishmania infantum and Trypanosoma brucei brucei. In parallel, the reduction potential of all molecules was measured by cyclic voltammetry. Structure-activity relationships first indicated that antileishmanial activity depends on an intramolecular hydrogen bond (described by X-ray diffraction) between the lactam function and the nitro group, which is responsible for an important shift of the redox potential (+0.3 V in comparison with 8-nitroquinoline). With the assistance of computational chemistry, a set of derivatives presenting a large range of redox potentials (from -1.1 to -0.45 V) was designed and provided a list of suitable molecules to be synthesized and tested. This approach highlighted that, in this series, only substrates with a redox potential above -0.6 V display activity toward L. infantum. Nevertheless, such relation between redox potentials and in vitro antiparasitic activities was not observed in T. b. brucei. Compound 22 is a new hit compound in the series, displaying both antileishmanial and antitrypanosomal activity along with a low cytotoxicity on the human HepG2 cell line. Compound 22 is selectively bioactivated by the type 1 nitroreductases (NTR1) of L. donovani and T. brucei brucei. Moreover, despite being mutagenic in the Ames test, as most of nitroaromatic derivatives, compound 22 was not genotoxic in the comet assay. Preliminary in vitro pharmacokinetic parameters were finally determined and pointed out a good in vitro microsomal stability (half-life > 40 min) and a 92% binding to human albumin

Nongenotoxic 3-Nitroimidazo[1,2-a]pyridines Are NTR1 Substrates That Display Potent in Vitro Antileishmanial Activity

Twenty nine original 3-nitroimidazo[1,2-a]pyridine derivatives, bearing a phenylthio (or benzylthio) moiety at position 8 of the scaffold, were synthesized. In vitro evaluation highlighted compound 5 as an antiparasitic hit molecule displaying low cytotoxicity for the human HepG2 cell line (CC50 > 100 mu M) alongside good antileishmanial activities (IC50 = 1-2.1 mu M) against L. donovani, L. infantum, and L. major; and good antitrypanosomal activities (IC50 = 1.3-2.2 mu M) against T. brucei brucei and T. cruzi, in comparison to several reference drugs such as miltefosine, fexinidazole, eflornithine, and benznidazole (IC50 = 0.6 to 13.3 mu M). Molecule 5, presenting a low reduction potential (E degrees = -0.63 V), was shown to be selectively bioactivated by the L. donovani type 1 nitroreductase (NTR1). Importantly, molecule 5 was neither mutagenic (negative Ames test), nor genotoxic (negative comet assay), in contrast to many other nitroaromatics. Molecule 5 showed poor microsomal stability; however, its main metabolite (sulfoxide) remained both active and nonmutagenic, making 5 a good candidate for further in vivo studies

Conception et surveillance environementale des zones à atmosphère contrôlée dans l'industrie pharmaceutique

AIX-MARSEILLE2-BU Pharmacie (130552105) / SudocSudocFranceF

Prise en charge de la gale à l'officine

AIX-MARSEILLE2-BU Pharmacie (130552105) / SudocSudocFranceF

TDAE-assisted synthesis of new imidazo[2,1-b]thiazole derivatives as anti-infectious agents

International audienceA series of new imidazo[2,1-b]thiazoles was prepared in moderate to good yields in a four step synthesis using the TDAE methodology from 6-chloromethyl-5-nitroimidazo[2,1-b]thiazole and keto esters, ketomalonates and ketolactams. All compounds were tested for their antibacterial and antifungal activities against four bacterial strains (two Gram positive and two Gram negative ones) and four yeasts. Among these synthesized 5-nitroimidazo[2,1-b]thiazoles, the compounds I and 6 showed potent antimicrobial activities against all candida. strains and compound 3e showed an interesting antifungal potential against Candida tropicalis. (C) 2009 Elsevier Masson SAS. All rights reserved

Synthesis and evaluation of original amidoximes as antileishmanial agents

International audienceAn original series of amidoxime derivatives was synthesized using manganese(III) acetate, Buchwald-Hartwig and Heck reactions. Two amidoximes (39 and 52) showed interesting in vitro activities toward Leishmania donovani promastigotes, exhibiting 8.3 and 8.8 mu M IC(50) values. Moreover, the cytotoxicity of these compounds was evaluated on human THP1 cells, giving access to the corresponding selectivity index. Among the 25 tested compounds, amidoximes 38 and 39 and diamidoximes 50 and 52 exhibited a better selectivity index than pentamidine used as a drug compound reference. (C) 2010 Elsevier Ltd. All rights reserved

In vitro antimicrobial activity of plants used in Cambodian traditional medicine

The purpose of the present study was to screen 27 plant species used in the traditional medicine of Cambodia for in vitro antibacterial and antifungal activities. Thirty-three methanolic extracts were tested against Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Mycobacterium smegmatis and Candida albicans. Screened by disk diffusion assay, the extracts showed antimicrobial activity especially on Gram-positive bacteria. None of the crude methanolic extracts showed activity against P. aeruginosa. Twenty-five selected extracts were evaluated using a micro-dilution test. Harrisonia perforata (roots) and Hymenodictyon excelsum (bark) exhibited a bactericidal effect against S. aureus at a concentration of 500 μg/ml. Azadirachta indica (bark), Harrisonia perforata (roots and stem) and Shorea obtusa (roots) exhibited a bactericidal effect against M. smegmatis at 250 μg/ml

Original quinazoline derivatives displaying antiplasmodial properties

International audienceThe multistep synthesis of new quinazoline-derived molecules and their in vitro antiplasmodial evaluation on the W2 chloroquino-resistant Plasmodium falciparum strain is described herein. These molecules have also been studied concerning their in vitro cytotoxicity toward two human cell lines (K652 and HepG2) in order to calculate their respective selectivity indexes (S.I.). Among the fourteen tested molecules, two exhibited both significant antiplasmodial activity (IC(50) = 0.95 and 1.3 mu M) and low toxicity (IC(50) \textgreater 100 or 125 mu M), compared with two reference drugs: chloroquine and doxycycline. The structure activity relationships establish that the molecular scaffold which exerts the best profile is the 6-nitro-2-(tosylmethyl)-N-(3-substituted-phenyl)-quinazolin-4-amine. The hit molecules were finally investigated regarding their potential action toward two other protozoa, Leishmania donovani and Toxoplasma gondii, showing that these molecules display a selective antiplasmodial activity. (C) 2009 Elsevier Masson SAS. All rights reserved

Antileishmanial pharmacomodulation in 8-nitroquinolin-2(1H)-one series

International audienceAn 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. Among them, molecules 17 and 19 were the most selective and were then tested in vitro on the intracellular amastigote stage of both L. donovani and Leishmania infantum, in parallel with complementary in vitro cytotoxicity assays on the macrophage cell lines THP-1 and J774A.1. Molecule 19 showed no activity on the amastigote stages of the parasites and some cytotoxicity on the J774A.1 cell line while molecule 17, less cytotoxic than 19, showed anti-amastigote activity in L. infantum, being 3 times less active than miltefosine but more active and selective than pentamidine. Nevertheless, hit-molecule 17 did not appear as selective as the parent compound. (C) 2015 Elsevier Ltd. All rights reserved

Looking for new antileishmanial derivatives in 8-nitroquinolin-2(1H)-one series

International audienceFrom 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. The results we obtained showed that the introduction of a substituent at position 4 of the antileishmanial pharmacophore can either lead to inactive or active derivatives, depending on the nature of the substituent. Aminated moieties appear as very unfavorable toward antileishmanial activity, while phenoxy or thiophenoxy moieties were shown to maintain the in vitro antileishmanial profile, especially when the phenyl ring of these moieties was substituted at the para or ortho position by a halogen atom (except fluorine), a trifluoromethyl group or a methyl group. Most of these derivatives showed a lack of solubility in the culture media which hindered the in vitro determination of both their cytotoxicity and activity against the intracellular amastigoste stage of L. donovani. (C) 2014 Elsevier Masson SAS. All rights reserved