Laboratoire Of Chimie Analytique

Tunis, Tunisia

Laboratoire Of Chimie Analytique

Tunis, Tunisia
Time filter
Source Type

Evdokimov N.M.,New Mexico Institute of Mining and Technology | Lamoral-Theys D.,Laboratoire Of Chimie Analytique | Mathieu V.,Free University of Colombia | Andolfi A.,University of Naples Federico II | And 7 more authors.
Bioorganic and Medicinal Chemistry | Year: 2011

As a continuation of our studies aimed at the development of a new cytostatic agent derived from an Amaryllidaceae alkaloid lycorine, we synthesized 32 analogues of this natural product. This set of synthetic analogues included compounds incorporating selective derivatization of the C1 versus C2 hydroxyl groups, aromatized ring C, lactamized N6 nitrogen, dihydroxylated C3-C3a olefin functionality, transposed olefin from C3-C3a to C2-C3 or C3a-C4, and C1 long-chain fatty esters. All synthesized compounds were evaluated for antiproliferative activities in vitro in a panel of tumor cell lines including those exhibiting resistance to proapoptotic stimuli and representing solid cancers associated with dismal prognoses, such as melanoma, glioblastoma, and non-small-cell lung cancer. Most active analogues were not discriminatory between cancer cells displaying resistance or sensitivity to apoptosis, indicating that these compounds are thus able to overcome the intrinsic resistance of cancer cells to pro-apoptotic stimuli. 1,2-Di-O-allyllycorine was identified as a lycorine analogue, which is 100 times more potent against a U373 human glioblastoma model than the parent natural product. Furthermore, a number of synthetic analogues were identified as promising for the forthcoming in vivo studies. © 2011 Elsevier Ltd. All rights reserved.

Hagege A.A.,University of Paris Descartes | Caudron E.,Laboratoire Of Chimie Analytique | Damy T.,Center Dinvestigation Clinique And Plateforme Of Ressources Biologiques | Millaire A.,Hopital Cardiologique | And 5 more authors.
Heart | Year: 2011

Background: Patients with Fabry disease (FD) show left ventricular hypertrophy (LVH) mimicking hypertrophic cardiomyopathy (HCM) of sarcomeric origin and might benefit, if detected early, from specific enzyme replacement therapy. The prevalence of FD in patients with LVH of 13 mm or greater, screened using the leucocyte alpha-galactosidase A (α-gal A) activity test, a technique that is difficult to apply routinely, ranged from 0% to 6%. Objective: To screen systematically for FD in patients with a diagnosis of HCM (LVH ≥15 mm) in primary cardiology practice, a validated, physician-friendly α-gal A assay was used on dried blood spots using a filter paper test. Design and patients: A cohort of 392 adults (278 men) followed for HCM were screened for FD. A standard blood test was used for confirmation in nine men in whom the α-gal A result was 40% or less. Results: Four men (1.5%; 1.8% of men ≥40 years vs 0% <40 years; all with α-gal A <30%), but no women, were diagnosed with FD. Index cases presented with diffuse but asymmetric LVH, with severe obstruction in one case and frequent high-grade atrioventricular conduction block necessitating a pacemaker in three cases. Family screening identified eight additional cases. Genotyping was performed successfully on DNA extracted from the filter papers. Conclusion: In male patients diagnosed as having HCM, pure FD cardiac variants are not exceptional and can be specifically identified using a simple filter-paper test. The sensitivity of this test is low in female patients.

Pinto R.C.,Laboratoire Of Chimie Analytique | Pinto R.C.,University of Aveiro | Locquet N.,French National Institute for Agricultural Research | Eveleigh L.,Laboratoire Of Chimie Analytique | And 3 more authors.
Food Chemistry | Year: 2010

In this work a new, easy and rapid MIR-ATR technique to monitor the thermal stability of oils is presented. The method uses a heated ATR apparatus set at selected temperatures to thermally modify the oils and simultaneously acquire spectra. Because of the larger sample surface to volume ratio, degradation reactions are faster compared to other heating methods. Three different edible oils (sunflower, olive and canola), are subjected to the method. Sunflower oil with or without tocopherol and at three different temperatures (130, 150 and 170 °C) was also analysed. Wavenumbers known to be relevant to oil degradation processes are selected to show the modifications in the spectra over time. © 2009 Elsevier Ltd. All rights reserved.

Blackman J.,Charles Sturt University | Rutledge D.N.,Laboratoire Of Chimie Analytique | Tesic D.,Charles Sturt University | Saliba A.,Charles Sturt University | Scollary G.R.,University of Melbourne
Analytica Chimica Acta | Year: 2010

The application of a multi-block statistical analysis method, known as Common Components and Specific Weight Analysis, to the determination of connections between sensory descriptors and analytical data for Hunter Valley Semillon is described. Sixteen wines were used in the data analysis with 15 sensory descriptors and 10 analytical measurements available for each wine. The multi-block analysis simplifies the comparison between the data sets and allows relationships between the sensory and analytical parameters to be readily ascertained, more effectively than a linear regression approach. A sweetness zone established the connections between several sensory descriptors and analytical measurements based on fructose. Glucose was not part of the sweetness connections, although glycerol was connected to the sensory sweetness descriptors. Sensory assessment of acidity was positively related to the titratable acidity and pH was negatively related. The malic acid concentration was also negatively related to sensory acidity and the possible reasons for this are described. Several sensory descriptors including toast, honey and kerosene were found to be in opposition to the sweetness sensory parameters and not connected to any analytical parameters. The outcomes of this multi-block treatment indicate the potential for using analytical measurements as a surrogate for sensory analysis. © 2009 Elsevier B.V. All rights reserved.

Baudelet D.,Lille 2 University of Health and Law | Baudelet D.,School of Advanced Engineering Studies | Lipka E.,Lille 2 University of Health and Law | Lipka E.,Laboratoire Of Chimie Analytique | And 5 more authors.
Current Medicinal Chemistry | Year: 2015

The purinergic receptor P2X7 is highly expressed in immune peripheral and central cells suggesting its important role in numerous diseases characterized by inflammatory processes like cancer, or neurodegenerative pathologies in relation with modulation of the immune system. Thereby, antagonization of this receptor may be a hopeful therapeutic strategy to treat a large range of diseases. Indeed, selective P2X7 antagonists display beneficial anti-inflammatory, analgesic, and in some cases, anticancer properties. This article will review the involvement of P2X7 in the immune system, the update of P2X7 antagonists series since 2009 and their promising therapeutic potential for the treatment of several immune- related diseases. © 2015 Bentham Science Publishers.

Balde E.S.,Laboratoire Of Toxicologie | Andolfi A.,University of Naples Federico II | Bruyere C.,Laboratoire Of Toxicologie | Cimmino A.,University of Naples Federico II | And 7 more authors.
Journal of Natural Products | Year: 2010

Fourteen metabolites, isolated from phytopathogenic and toxigenic fungi, were evaluated for their in vitro antigrowth activity for six distinct cancer cell lines, using the MTT colorimetric assay. Bislongiquinolide (1) and dihydrotrichodimerol (5), which belong to the bisorbicillinoid structural class, displayed significant growth inhibitory activity against the six cancer cell lines studied, while the remaining compounds displayed weak or no activity. The data show that 1 and 5 have similar growth inhibitory activities with respect to those cancer cell lines that display certain levels of resistance to pro-apoptotic stimuli or those that are sensitive to apoptosis. Quantitative videomicroscopy analysis revealed that 1 and 5 exert their antiproliferative effect through cytostatic and not cytotoxic activity. The preliminary results from the current study have stimulated further structure-activity investigations with respect to the growth inhibitory activity of compounds belonging to the bisorbicillinoid group. © 2010 The American Chemical Society and American Society of Pharmacognosy.

Boujelbane F.,Laboratoire Of Chimie Analytique | Oueslati F.,Laboratoire National Of Controle Des Medicaments Et Of Depistage Du Dopage | Hamida N.B.,Laboratoire Of Chimie Analytique
Desalination | Year: 2010

The aim of the present study was to attempt to describe a rapid procedure of purification and determination of the Zectran, Aminocarb and Bendiocarb in aqueous media using Reversed-phase high-performance liquid chromatography (RP-HPLC) coupled to electrospray ionisation mass spectrometry (ESI). Different solids phases ODS sorbents were evaluated for the extraction of analytes in water. Sensitivity was evaluated by determining the limit of detection and recoveries of these compounds. The optimum conditions of extraction were applied for the screening of these substances in river water sample (Oued Madjerda). © 2009 Elsevier B.V. All rights reserved.

Sarr F.S.,Laboratoire Of Chimie Analytique | Andre C.,Laboratoire Of Chimie Analytique | Guillaume Y.C.,Laboratoire Of Chimie Analytique
Journal of Pharmaceutical and Biomedical Analysis | Year: 2010

In a previous paper, using a biophysical model system to study the passive diffusion of the statin molecules through the cell membrane, our group demonstrated that statins could cross biological membrane by passive diffusion (Sarr et al. [40]). However, in the liver, the uptake of statins would also be mediated by organic anion transporting polypeptides (Oatps) like Oatp2 a member of this family. Thus, a novel biochromatographic approach was developed in our laboratory to study the transmembrane transport of statins and an Oatp2 inhibitor via this carrier family. For this, the Oatp2 protein was immobilized via its amino groups on a chromatographic support using an "in situ" immobilization technique. For the first time, using this novel biochromatographic concept, the effect of magnesium chloride salt (MgCl2) on the pharmacomolecule-Oatp2 binding was investigated. It was shown an Mg2+-dependent pharmacomolecule-protein association and a potential facilitated diffusion of these pharmacomolecules into biological membrane. This association process was due to the central positive potential pore of the Oatp2. Indeed, at pH 7.4, all the pharmacomolecules studied were ionized (i.e. negatively charged) and so interact with this positive potential pore. However, an increase of the Mg2+ concentration led a decrease of the pharmacomolecule-Oatp2 association attributed to ion pair formations between the Mg2+ cation and molecules. Moreover, the decrease of this affinity could be explained by an ion attraction between the Cl- anion of the MgCl2 salt and the positively charged pore of the protein. This novel biochromatographic column could be useful to find a specific reversible inhibitor for these transporters and so open new perspectives to be investigated. © 2009 Elsevier B.V. All rights reserved.

Cabordery A.C.,Laboratoire Of Chimie Analytique | Toussaint M.,University of Lille Nord de France | Bonte J.P.,Laboratoire Of Chimie Analytique | Melnyk P.,University of Lille Nord de France | And 2 more authors.
Journal of Chromatography A | Year: 2010

Stereospecific separations of seven Tic-hydantoin sigma-1 agonists were performed by both HPLC method using derivatized cellulose and amylose chiral stationary phases and capillary electrophoresis (CE) method using neutral and anionic cyclodextrins added in the background electrolyte (BGE). An optimal baseline separation (Rs>3.3 with analysis times<25min) was readily obtained with all silica-based celluloses and amyloses using a normal-phase methodology. CE was used as an alternative technique to HPLC for the Tic-hydantoin derivatives separation. The enantiomers were fully resolved with highly sulfated β-cyclodextrins at pH 2.5 (Rs>1.5 with analysis times <11min). Both methods were validated in terms of linearity, detection and quantification limits. They were used to check the enantiomeric purity of the enantiomers. © 2010 Elsevier B.V.

Lipka E.,Laboratoire Of Chimie Analytique | Danel C.,Laboratoire Of Chimie Analytique | Yous S.,University of Lille Nord de France | Bonte J.-P.,Laboratoire Of Chimie Analytique | Vaccher C.,Laboratoire Of Chimie Analytique
Electrophoresis | Year: 2010

In this study, baseline separation of the stereoisomers of six tetrahydronaphthalenic derivatives (agonists and antagonists for the melatonin (N-acetyl-5-methoxytryptamin) binding sites) was successfully achieved using CE and CDs as chiral selectors. The method for the simultaneous chiral separation of the four stereoisomers uses a capillary dynamically coated with polyethylene oxide and a dual CD system. Optimisation was performed first upon the constituents of the CD system, by varying neutral and anionic CD type, size and concentration, at first in mono-CD systems and subsequently in dual neutral/anionic CD systems. Once these characteristics of the dual CD system were established, operational parameters such as voltage and temperature were then optimised. Under the optimal conditions (i.e. 1.5% w/v of highly S-β-CD and 10mM of γ-CD in 25mM phosphate buffer (pH 2.5) as the BGE, separation voltage 20 kV and a temperature of 25°C), complete resolution of the six molecules was accomplished. Preliminary results for repeatability and the migration order of the optimised method are described. © 2010 Wiley-VCH Verlag GmbH & Co. KGaA.

Loading Laboratoire Of Chimie Analytique collaborators
Loading Laboratoire Of Chimie Analytique collaborators