87 results on '"CLHP"'
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2. Étude de l’activité antibactérienne et identification des substances bioactives de différents extraits de Myrtus communis.
- Author
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Belhadji, K. A., Bouzouina, M., and Addou, A.
- Subjects
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DICHLOROMETHANE , *STAPHYLOCOCCUS aureus infections , *URINARY tract infections , *MICROCOCCACEAE , *METABOLITES , *PLANT metabolites , *AROMATIC plants - Abstract
The aim of this study is to evaluate the antibacterial activity of four organic extracts: petroleum ether (PE), dichloromethane (DCM), methanol (MeOH), ethanol (EtOH) and aqueous extracts (digestion, decoction, maceration, and infusion), prepared from the leaves of the aromatic plant Myrtus communis. Phytochemical screening revealed a richness of this plant in secondary metabolites such as flavonoids, phenolic acids, anthraquinones, tannins, sterols, and terpenes. The antimicrobial activity of Myrtus communis extracts was evaluated in vitro by the agar diffusion method on two strains of bacteria commonly encountered in urinary tract infections and lithiasis: Staphylococcus aureus ATCC (25923), Proteus mirabilis reference strain ATCC (43862) and Proteus mirabilis clinical strain. All these strains were found to be sensitive to the extracts studied. The minimum inhibitory concentrations (MIC) recorded varied from 3.75 to 15 mg/ml, while the minimum bactericidal concentrations (MBC) were between 7.5 and 30 mg/ml. This activity is essentially bactericidal in nature. The analyses showed the presence of phenolic groups with antibacterial capabilities. The obtained results proved an interesting antibacterial activity of the majority of Myrtus communis extracts, translated by zones of inhibition of important diameter: extracts of methanol (28 mm), petroleum ether (28 mm) and aqueous solution (25 mm) towards Proteus mirabilis reference strain ATCC (43862), Staphylococcus aureus ATCC (25923) and Proteus mirabilis clinical strain, respectively. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
3. Vérification de la méthode de dosage de l'HbA1c par HPLC au laboratoire de biochimie.
- Author
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Chemsi, Hicham and Kamal, Nabiha
- Abstract
Introduction : la vérification/validation d'une technique consiste à évaluer les performances du processus analytique, à les quantifier selon un protocole opératoire standardisé puis les comparer à des critères définis. L'objectif de ce travail est d'évaluer les performances analytiques d'un analyseur de l'HbA1c utilisant une technique CLHP. Matériels et méthodes : les méthodes utilisées sont les recommandations du protocole Valtec et du guide technique d'accréditation en santé humaine, pour l'évaluation des performances analytiques des analyseurs. Les données ont été exploitées à l'aide des logiciels VDM, Microsoft Office Excel et SPSS V10 au risque de 5 %. Résultats : la répétabilité et la fidélité intermédiaire étaient satisfaisantes avec des valeurs de CV qui étaient respectivement de 0,338 % et 1,25 % pour le niveau moyen (HbA1c = 5,4 %) et 0,17 % et 4,09 % pour le niveau haut (HbA1c = 10,7 %). L'exactitude a été établie à partir des résultats des EEQ en calculant le biais et qui a montré une conformité par rapport aux valeurs cibles. La linéarité est suffisante dans le contexte d'utilisation. L'approche de l'incertitude de mesure ainsi que la contamination inter-échantillons ont été jugées satisfaisantes pour l'utilisation routinière. Conclusion : l'analyseur vérifié présente des performances analytiques requises pour un dosage fiable de l'HbA1c. Introduction : the verification/validation of a technique consists in evaluating the performance of the analytical process, quantifying them according to a standardized operating procedure and then judging them according to defined criteria. We evaluated the analytical performances of the analyzer using ion-exchange HPLC for the measurement of HbA1c. Materials and methods : based on the recommendations of Valtec protocol and the technical guide for accreditation in Human Health, edited by the COFRAC we evaluated the analytical performance of the analyzers. Data was analyzed using Microsoft Office Excel, VDM softwares and SPSS V10 at 5 % risk. Results : repeatability and intermediate fidelity were satisfactory with CV values of 0.338 % and 1.25 % respectively for the mean level (HbA1c = 5.4 %) and 0.17 % and 4.09 % for the high level (HbA1c = 10.7 %). The accuracy was derived from the EEQ results by calculating the bias and showing compliance with the target values. Linearity is sufficient in the context of use. The measurement uncertainty approach and the inter-sample contamination were found to be satisfactory for routine use. Conclusion : from our study results, the verified analyser presents the analytical performance required for a determination of HbA1c in a reliably way. [ABSTRACT FROM AUTHOR]
- Published
- 2020
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4. Catharanthus roseus Plant Extracts (Cultivated in vitro and ex vitro) Protect Wistar Rats Against Chemically Induced Liver Carcinogenesis.
- Author
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Mujib, A., Gupta, D., and Tonk, D.
- Abstract
Copyright of Phytothérapie is the property of John Libbey Eurotext Ltd. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2018
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5. Physicochemical stability of norepinephrine bitartrate in polypropylene syringes at high concentrations for intensive care units
- Author
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J. Vigneron, E. D’Huart, Igor Clarot, Béatrice Demoré, Centre Hospitalier Régional Universitaire de Nancy (CHRU Nancy), Cibles thérapeutiques, formulation et expertise pré-clinique du médicament (CITHEFOR), Université de Lorraine (UL), and Maladies chroniques, santé perçue, et processus d'adaptation (APEMAC)
- Subjects
Light ,Drug Storage ,Pharmaceutical Science ,CLHP ,Polypropylenes ,Stabilité ,030226 pharmacology & pharmacy ,High-performance liquid chromatography ,Norepinephrine (medication) ,Norepinephrine ,03 medical and health sciences ,chemistry.chemical_compound ,0302 clinical medicine ,Drug Stability ,Intensive care ,medicine ,Vasoconstrictor Agents ,Intensive care unit ,Furaldehyde ,Soins intensifs ,030212 general & internal medicine ,Chromatography, High Pressure Liquid ,Syringe ,Pharmacology ,Polypropylene ,Noradrénaline ,Chromatography ,Chemistry ,Syringes ,Temperature ,Reproducibility of Results ,Hydrogen-Ion Concentration ,Intensive Care Units ,[SDV.SPEE]Life Sciences [q-bio]/Santé publique et épidémiologie ,Physical stability ,Chemical stability ,HPLC ,Stability ,Norepinephrine Bitartrate ,medicine.drug - Abstract
Summary Objectives Norepinephrine is usually used in emergency situations such as in intensive care units (ICUs) for the restoration of blood pressure. The objective was to study the stability of highly-concentrated solutions of norepinephrine at 0.50 mg/mL and 1.16 mg/mL, diluted in glucose 5% (G5%) in polypropylene syringes, protected or not from light, up to 48 h. Materials and methods Chemical stability was analysed by high-performance liquid chromatography coupled to photodiode array detection at each time of the analysis. The method was validated according to the International Conference on Harmonisation Q2(R1). Physical stability was evaluated by visual and subvisual inspection. Three syringes for each condition were prepared. At each time of the analysis, three samples were analysed for each syringe. pH values were evaluated at each moment of the analysis. Results Solutions of norepinephrine at 0.50 and 1.16 mg/mL, diluted in G5%, with or without protection from light, retained more than 95.0% of the initial concentration after a 48-hour storage at 20–25 °C. No visual and subvisual modification occured during the stability study. No degradation product appearing during the stressed degradation was observed during the study but an additional peak with a relative retention at 0.66 was observed and constant. This peak was identified as 5-hydroxymethylfurfural, a degradation product of glucose. Conclusion Norepinephrine diluted in G5% at 0.50 mg/mL and 1.16 mg/mL was physically and chemically stable over a period of 48 hours at room temperature. These stability data of highly concentrated solutions provide additional knowledge to assist intensive care services in daily practice.
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- 2019
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6. Environmental effects on fruit composition of cloudberry/bakeapple (Rubus chamaemorus L.) grown in southern Labrador, Canada.
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Li, Jiabai, Percival, David, Hoyle, Jeff, Jin Yue, White, Jane, Head, Krista, and Pruski, Kris
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CLOUDBERRY ,FRUIT composition ,AGRICULTURAL climatology ,ACIDITY ,PHENOLS ,ANTHOCYANINS ,CHLOROGENIC acid ,CAFFEIC acid - Abstract
Copyright of Canadian Journal of Plant Science is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2015
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7. Scientific Research on Purple Mollusc Pigments on Archaeological Artifacts
- Author
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Koren, Zvi C.
- Subjects
History ,Τελ Ντορ ,archéométrie ,Λέξεις κλειδιά Πορφυρή χρωστική ουσία ,HBLA ,Δαρείος ,Hexaplex trunculus ,dibromoindigo ,Muricidae ,HIS002010 ,Hérode ,Darius ,Ηρώδης ,Classics ,Tel Kabri ,Hplc ,techniques de fabrication ,couleur ,Υχυα ,Tel Dor ,Purple pigment ,Τελ Καμπρί ,Clhp ,βαθυγάλανη βαφή ,Pourpre ,peinture ,indigoïdes ,αρχαιομετρία ,Herod ,archaeometry - Abstract
The optimal technique for determining the chemical compositions of archaeological purple pigments and dyes from molluscan sources is the high-performance liquid chromatography (HPLC) method. This technique has been applied to the qualitative and quantitative multi-component fingerprinting of purple pigments extracted from various Mediterranean Muricidae molluscs, commonly known as Murex sea snails. The results on modern and archaeological purple pigments show that the colourants in these samples belong to three related chemical groups: indigoids, indirubinoids, and isatinoids. Discoveries on archaeological artifacts from the ancient Near East made by this laboratory include: decoding the ancient optimal method of purple-dyeing; detection of the purple pigment painted on a 2500-year old King Darius I marble jar; identifying 2000-year old biblical Argaman and Tekhelet dyeings from Masada. La meilleure méthode pour déterminer la composition chimique des pigments et des teintures archéologiques pourpres issus de mollusques est la chromatographie en phase liquide haute performance. On a utilisé cette technique pour l’analyse qualitative et quantitative des différents éléments constituant la signature de la pourpre extraite des différentes variétés de mollusques du type Muricidae rencontrées en Méditerranée, plus communément connues sous le nom de Murex. Les résultats montrent que les colorants rentrant dans la composition de la pourpre appartiennent à trois classes chimiques : les indigoïdes, les indirubinoïdes et les isatinoïdes. Au nombre des découvertes réalisées par notre laboratoire sur des objets archéologiques provenant du Proche-Orient, on retiendra la mise en évidence du procédé antique optimal pour obtenir la teinte pourpre ; la découverte d’un pigment pourpre sur une jarre royale de marbre vieille de 2500 ans et datant de l’époque du roi perse Darius Ier ; l’identification de l’Argaman et du Tekhelet bibliques vieux de 2000 ans et provenant de Masada. Η βέλτιστη τεχνική για τον καθορισμό της χημικής σύνθεσης αρχαιολογικών πορφυρών χρωστικών ουσιών και βαφών από μαλάκια είναι η μέθοδος της υγρής χρωματογραφίας υψηλής απόδοσης. Η τεχνική αυτή έχει εφαρμοστεί για την ποιοτική και ποσοτική ανάλυση πορφυρών χρωστικών ουσιών που προέρχονται από διάφορα μεσογειακά μαλάκια Muricidae, που είναι ευρέως γνωστά ως murex. Τα αποτελέσματα σε σύγχρονες και αρχαιολογικές πορφυρές βαφές δείχνουν ότι οι χρωστικές ουσίες στα δείγματα αυτά ανήκουν σε τρία συσχετιζόμενα χημικά σύνολα: τα σχετικά με τη βαθυγάλανη, την ερυθρή και την κόκκινη βαφή. Οι ανακαλύψεις σε αρχαιολογικά αντικείμενα από την αρχαία Εγγύς Ανατολή που έγιναν σε αυτό το εργαστήριο περιλαμβάνουν: την αποκωδικοποίηση της αρχαίας βέλτισης μεθόδου για την πορφυρή βαφή· την ανίχνευση πορφυράς χρωστικής ουσίας πάνω σε ένα μαρμάρινο αγγείο του βασιλιά Δαρείου Α΄ ηλικίας 2500 ετών· την ταύτιση των βιβλικών βαφών Αργκαμάν και Τεκελέτ, ηλικίας 2000 ετών, από τη Μάσαδα.
- Published
- 2021
8. Comprehensive Modeling of a Chemical Looping Heat Pump with a Reverse Fuel Cell
- Author
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Kim, Junyoung, James, Nelson A., Braun, James E., Groll, Eckhard A., and Ziviani, Davide
- Subjects
fuel cell ,energy savings ,mechanistic model ,CLHP ,non-vapor compression - Abstract
HVAC, refrigeration, and water heating accounted for approximately 22 quads of primary energy consumed in the United States in 2018, according to US EIA. Most of HVAC&R industry still relies on vapor compression and heat-driven technologies. The development of highly efficient technologies that would significantly improve both COP and annual energy savings is an open challenge for the new decade. Among the novel technologies, the Chemical Looping Heat Pump (CLHP) combined with a reverse fuel cell has been modeled with estimates of a COP increase of over 20% relative to a conventional vapor compression (VC) cycle. However, limitations of simplified modeling efforts necessitate the development of a comprehensive mechanistic model to predict several physical phenomena for varying operating conditions and more accurately estimate performance. In this work, a charge-sensitive mechanistic modeling approach is utilized to predict the performance of the CLHP system. A thermodynamic model is coupled with a discretized fuel cell model to estimate the energy savings potential. A moving boundary model is adopted to assess the steady-state heat transfer rate in the heat exchanger. Sensitivity analyses are used to identify the system behaviors and performance.
- Published
- 2021
9. Development and validation of a stability-indicating high performance liquid chromatographic assay for determination of cariprazine in bulk form and in drug product.
- Author
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Toujani E, Mejri W, Lassoued HE, Toujani S, Fliss O, Cheikh MHB, and Safta F
- Subjects
- Chromatography, Liquid, Chromatography, High Pressure Liquid methods, Drug Stability, Hydrolysis, Oxidation-Reduction, Photolysis, Tandem Mass Spectrometry methods, Piperazines
- Abstract
The aim of the present study is to develop a stability indicating high performance liquid chromatographic method for the determination of cariprazine in bulk substance and in drug product. The chromatographic separation was carried out using a Phenomenex Kinetex® C18 column (5μm, 250×4.6mm) and a mobile phase consisting of acetonitrile-potassium dihydrogen orthophosphate buffer (pH 4; 50mM) (30:70, v/v), at a flow rate of 1mlmin -1 and UV detection at 248nm. The column was maintained at 25°C and an injection volume of 20μL was used. Stress testing of cariprazine bulk substance and drug product was performed according to the International Conference on Harmonization (ICH) Q1A (R2) guideline. Various stress conditions were tested including acidic, alkaline and neutral hydrolysis, humidity, oxidation, dry heat and photolysis. A total of three degradation products (DPs) were formed. Among them two DPs were successfully characterized with the liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis., (Copyright © 2022 Académie Nationale de Pharmacie. Published by Elsevier Masson SAS. All rights reserved.)
- Published
- 2023
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10. Distribution of the foliar fungal endophyte Phialocephala scopiformis and its toxin in the crown of a mature white spruce tree as revealed by chemical and qPCR analyses.
- Author
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Frasz, Samantha L., Walker, Allison K., Nsiama, Tienabe K., Adams, Gregory W., and Miller, J. David
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WHITE spruce , *ENDOPHYTIC fungi , *MYCOTOXINS , *CROWNS (Botany) , *INSECT baits & repellents - Abstract
Phialocephala scopiformis Kowalski & Kehr is a foliar fungal endophyte of white spruce ( Picea glauca (Moench) Voss) that produces the anti-insect compound rugulosin and other compounds in lower amounts. Seedlings inoculated with this and other toxigenic endophytes have increased tolerance to the spruce budworm Choristoneura fumiferana (Clemens, 1865). The presence of rugulosin in the diet and in needles infected by P. scopiformis reduces the growth rate of the insect. One of 300 white spruce trees inoculated as a seedling in 2001 was chosen to investigate the distribution of P. scopiformis and its principal toxin rugulosin throughout the crown. To facilitate the detection of the fungus in small samples, a qPCR assay was developed based on the ITS region of fungal ribosomal DNA targeting a genetic polymorphism unique to P. scopiformis. The assay was specific, with a method limit of detection 100 ng mycelium per gram needle sample with high reproducibility and accuracy. We found that 11 years after inoculation, P. scopiformis DAOM 229536 and its toxin were detectable in needle samples distributed throughout the crown. Of the 109 samples tested, 100% of the rugulosin-positive samples also tested positive for P. scopiformis DAOM 229536 DNA in the qPCR assay. The mean and median needle rugulosin concentrations were >2 times that required to reduce the growth of spruce budworm. [ABSTRACT FROM AUTHOR]
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- 2014
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11. Ethyl lactate as an environmentally friendly HPLC mobile-phase modifier in the analysis of acetaminophen, caffeine, and ASA.
- Author
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Judge, Michael D. and Aab, Curtis
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HIGH performance liquid chromatography , *LACTATES , *ACETAMINOPHEN analysis , *CAFFEINE , *ASPIRIN , *EXTRACTION (Chemistry) , *SUSTAINABLE chemistry - Abstract
Ethyl lactate (EL) has been investigated as an environmentally friendly organic modifier for use in HPLC mobile phases. EL shows significant promise in this regard when used under optimal conditions. In conjunction with a standard C18 column at a temperature of 60 °C, a mobile phase composed of 87% water, 10% EL, and 3% acetic acid is capable of baseline resolution of three standard pharmaceutical analytes (acetaminophen, caffeine, and acetylsalicylic acid) in under three minutes. This same mobile phase was found to be capable of extraction of these same analytes from consumer pain relief tablets with essentially 100% efficiency. Using a core-shell C18 column at 40 °C, similar resolution and run times with these analytes are possible using the same mobile phase but with a reduced EL content of only 2.5%. [ABSTRACT FROM AUTHOR]
- Published
- 2013
- Full Text
- View/download PDF
12. Mise au point et validation d’une méthode de dosage de la teicoplanine par chromatographie liquide à haute performance.
- Author
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Jebabli, Nadia, Gaïes, Emna, Trabelsi, Sameh, Salouage, Issam, Charfi, Rim, Lakhal, Mohamed, and Klouz, Anis
- Subjects
HIGH performance liquid chromatography ,GLYCOPEPTIDES ,BLOOD serum analysis ,ACETONITRILE ,PHOSPHATES ,SULFAMETHOXAZOLE - Abstract
Copyright of Revue Francophone des Laboratoires is the property of Elsevier B.V. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2013
- Full Text
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13. Mise au point et validation d'une méthode de dosage de l'amphotéricine B par chromatographie liquide à haute performance.
- Author
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Gaïes, Emna, Ben Ali, Ridha, Trabelsi, Sameh, Jebabli, Nadia, Salouage, Issam, Charfi, Rim, Lakhal, Mohamed, and Klouz, Anis
- Subjects
MYCOSIS fungoides ,AMPHOTERICIN B ,HIGH performance liquid chromatography ,ANTIFUNGAL agents ,CHROMATOGRAPHIC analysis ,ULTRAVIOLET detectors ,THERAPEUTICS - Abstract
Copyright of Revue Francophone des Laboratoires is the property of Elsevier B.V. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2013
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14. A new HPLC method for the determination of tocopherol in rat plasma.
- Author
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Ghodbane, Soumaya, Lahbib, Aida, Ennaceur, Soukaina, Sakly, Mohsen, and Driss, Mohamed Ridha
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HIGH performance liquid chromatography , *VITAMIN E , *LABORATORY rats , *BLOOD plasma , *CADMIUM poisoning , *FOOD poisoning , *FLUORESCENCE - Abstract
Objective: The objective of the present work is the simplification of sample treatment for vitamin E measurements in rat plasma by high-performance liquid chromatography (HPLC), then the evaluation of the effect of cadmium treatment on the vitamin E level. Methods: A HPLC method to determine vitamin E was developed with direct extraction with n-hexane-dichloromethane. The dry residue was redissolved in methanol. The method employs a Supelco Discoveryr® C18 column and methanol/water (95:5, v/v) as the mobile phase. After being developed, the method was validated with a fluorescence detector. To examine the effects of exogenous cadmium on the plasma vitamin E concentrations, male Wistar rats (weighing 150 ± 20 g) were exposed for 48 h and 10 days to oral intake of 15 and 30 mg/L cadmium (as CdCl2) and vitamin E (10 mg/Kg of diet) simultaneously. Results: This method makes sample treatment easier, especially when working with a large number of samples. It has proved to be selective, linear, accurate and precise. Intoxication with cadmium was followed by a significant decrease in plasma vitamin E concentrations. The lowest level was obtained in the 30 mg/L dosing group after 10 days of cadmium administration. Conclusion: We describe a rapid reversed-phase (RP) HPLC procedure for the determination of vitamin E in plasma. This method might be useful in routine assessment because it saves on solvents and chromatographic time. Interestingly, a-tocopherol may play an important role in preventing oxidative stress induced by cadmium exposure by scavenging free radicals. [ABSTRACT FROM AUTHOR]
- Published
- 2013
- Full Text
- View/download PDF
15. La Spectroscopie Raman (SR) : un nouvel outil adapté au contrôle de qualité analytique des préparations injectables en milieu de soins. Comparaison de la SR aux techniques CLHP et UV/visible-IRTF appliquée à la classe des anthracyclines en cancérologie
- Author
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Bourget, P., Amin, A., Moriceau, A., Cassard, B., Vidal, F., and Clement, R.
- Subjects
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RAMAN spectroscopy , *QUALITY control , *INJECTIONS , *MEDICAL care , *HIGH performance liquid chromatography , *FOURIER transform infrared spectroscopy , *ANTHRACYCLINES , *ANTINEOPLASTIC agents - Abstract
Abstract: The study compares the performances of three analytical methods devoted to Analytical Quality Control (AQC) of therapeutic solutions formed into care environment, we are talking about Therapeutics ObjectsTN (TOsTN). We explored the pharmacological model of two widely used anthracyclines i.e. adriamycin and epirubicin. We compared the performance of the HPLC versus two vibrational spectroscopic techniques: a tandem UV/Vis-FTIR on one hand and Raman Spectroscopy (RS) on the other. The three methods give good results for the key criteria of repeatability, of reproducibility and, of accuracy. A Spearman and a Kendall correlation test confirms the noninferiority of the vibrational techniques as an alternative to the reference method (HPLC). The selection of bands for characterization and quantification by RS is the results of a gradual process adjustment, at the intercept of matrix effects. From the perspective of a AQC associated to release of TOs, RS displays various advantages: (a) to decide quickly (∼2min), simultaneously and without intrusion or withdrawal on both the nature of a packaging than on a solvant and this, regardless of the compound of interest; it is the founder asset of the method, (b) to explore qualitatively and quantitatively any kinds of TOs, (c) operator safety is guaranteed during production and in the laboratory, (d) the suppression of analytical releases or waste contribute to protects the environment, (e) the suppression.of consumables, (f) a negligible costs of maintenance, (g) a small budget of technicians training. These results already show that the SR technology is potentially a strong contributor to the safety of the medication cycle and fight against the iatrogenic effects of drugs. [Copyright &y& Elsevier]
- Published
- 2012
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16. Intoxication volontaire au vérapamil et au bisoprolol : à propos d'un cas.
- Author
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Campergue, Jean-Baptiste, Narci, Clément, Citterio-Quentin, Antony, Faucher, Etienne, Robert, Jean-Michel, Argaud, Laurent, and Moulsma, Mustapha
- Subjects
- *
VERAPAMIL , *BISOPROLOL , *THERAPEUTICS , *HYPERTENSION - Abstract
Objective: Primary essential high blood pressure is treated by different cardiotropic drugs which have similar toxicological effects. Our study is about a verapamil and bisoprolol poisoning, which was at first labelled as bisoprolol only, after a comprehensive toxicological analysis. Materials and methods: This poisoning was diagnosed by repeated HPLC/UV/DAD screenings. Results: Two successive screenings showed both verapamil and bisoprolol poisoning. Verapamil toxic concentrations were revealed after the decrease in bisoprolol concentrations, explaining the persistence in time of cardiovascular symptoms. The patient stayed for several days in an intensive care unit. Verapamil concentrations remained at a toxic level for six days. Conclusion: Because of the presence of sustained-release forms and unchanged clinical signs, repeating a comprehensive toxicological screening, instead of monitoring the initially suspected drug, helped in the screening and the follow-up of this multiple cardiotopic drug poisoning. [ABSTRACT FROM AUTHOR]
- Published
- 2012
- Full Text
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17. Mise au point et validation d’une méthode de dosage de la 25-hydroxy-vitamine D3 par chromatographie liquide haute performance.
- Author
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Charfi, Rim, Belhadj, Raja, Lahbib, Aïda, Gaïes, Emna, Jebabli, Nadia, Trabelsi, Sameh, Salouage, Issam, Lakhal, Mohamed, and Klouz, Anis
- Subjects
BLOOD plasma ,CHOLECALCIFEROL ,HIGH performance liquid chromatography ,BONE metabolism ,CHROMATOGRAPHIC analysis ,GENE expression - Abstract
Copyright of Revue Francophone des Laboratoires is the property of Elsevier B.V. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2011
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18. Évaluation de l'activité antimicrobienne de Thymus vulgaris et de Laurus nobilis, plantes utilisées en médecine traditionnelle.
- Author
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Yakhlef, G., Laroui, S., Hambaba, L., Aberkane, M.-C., and Ayachi, A.
- Abstract
Copyright of Phytothérapie is the property of John Libbey Eurotext Ltd. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2011
- Full Text
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19. A new arginase enzymatic reactor: Development and application for the research of plant-derived inhibitors
- Author
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André, Claire, Herlem, Guillaume, Gharbi, Tijani, and Guillaume, Yves Claude
- Subjects
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ENZYME inhibitors , *CHEMICAL reactors , *ETHYLENEDIAMINE , *HIGH performance liquid chromatography , *PLANT enzymes , *CHOCOLATE , *PLANT extracts , *GLUTARALDEHYDE - Abstract
Abstract: This work was dedicated to the development of a new micro immobilized enzyme reactor (IMER) by using an in situ procedure. Arginase was covalently immobilized on an ethylenediamine (EDA) monolithic convective interaction media (CIM) disk (12mm×3mm i.d.) previously derivatized with glutaraldehyde. The activity of this IMER was investigated by inserting this micro-IMER in a HPLC system. The effect of the arginase inhibitors was evaluated by the simultaneous injection of each inhibitor with the nitro guanidino benzene (NGB) substrate. The relative IC50 values were found in agreement with those derived by the conventional spectrometric method. This arginase micro-IMER system was also used to study the effects of plant-derived products on the arginase activity. The pet ether extract from the stem bark of the plant Ficus glomerata Roxob. and the procyanidin oligomers of cocoa and chocolate inhibit the arginase activity. Our results confirmed the direct effect of some plant extracts on the arginase activity and their interest in therapies for treating several NO-dependent smooth disorders. [Copyright &y& Elsevier]
- Published
- 2011
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20. Dosage de l’homocystéine plasmatique, comparaison de deux méthodes : CLHP versus immunonéphélémétrie.
- Author
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Lebreton, A., Bonneau, C., Bouvier, D., Albert, A., Ughetto, S., Mulliez, A., Cadau, M., Chamson, A., Sapin, V., and Fogli, A.
- Subjects
HOMOCYSTEINE ,METHIONINE ,AMINO acids ,CHEMILUMINESCENCE immunoassay ,CARDIOVASCULAR diseases risk factors ,QUANTITATIVE research ,HIGH performance liquid chromatography - Abstract
Copyright of IBS, Immuno-analyse & Biologie Specialisee is the property of Elsevier B.V. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2009
- Full Text
- View/download PDF
21. Validation de la méthode de dosage de l’hémoglobine A1c par CLHP sur D-10® Bio-Rad.
- Author
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Ouzzif, Zohra, Renard, Christophe, Dami, Abdellah, Daunizeau, Alain, and Derouiche, Mostapha
- Subjects
HIGH performance liquid chromatography ,HEMOGLOBINS ,PROTEIN analysis ,REGRESSION analysis ,ANIONS ,MEDICAL care - Abstract
Copyright of Revue Francophone des Laboratoires is the property of Elsevier B.V. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2009
- Full Text
- View/download PDF
22. Interprétation des catécholamines urinaires.
- Author
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Garnier, Jean-Pierre
- Subjects
CATECHOLAMINES ,URINALYSIS ,HOMOVANILLIC acid ,HIGH performance liquid chromatography ,NEUROENDOCRINE tumors ,DOPAMINE ,DIAGNOSIS - Abstract
Copyright of Revue Francophone des Laboratoires is the property of Elsevier B.V. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2009
- Full Text
- View/download PDF
23. Catharanthus roseus plant extracts (cultivated in vitro and ex vitro) protect Wistar rats against chemically induced liver carcinogenesis
- Author
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Mujib, A., Gupta, D., and Tonk, D.
- Published
- 2017
- Full Text
- View/download PDF
24. A novel chiral column for the HPLC separation of a series of dansyl amino and arylalkanoic acids
- Author
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Guillaume, Yves-Claude and André, Claire
- Subjects
- *
HIGH performance liquid chromatography , *CHROMATOGRAPHIC analysis , *LIQUID chromatography , *HIGH pressure (Science) - Abstract
Abstract: In a previous paper [C. Andre, M. Thomassin, A. Umrayami, L. Ismaili, B. Refouvelet, Y.C. Guillaume, Talanta 71 (2007) 1817] a novel cyclic hexapeptide molecule dissolved in the mobile phase was evaluated as a chiral selector (CS) for the enantiomer separation of a series of dansyl amino and arylalkanoic acids using high performance liquid chromatography (HPLC). In this paper, this CS was immobilized to the surface of a monolithic support and the enantioselectivity and the performance of this novel column are discussed. [Copyright &y& Elsevier]
- Published
- 2008
- Full Text
- View/download PDF
25. Contribution de la chimie analytique à l'étude des exsudats végétaux styrax, storax et benjoin
- Author
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Hovaneissian, Michael, Archier, Paul, Mathe, Carole, and Vieillescazes, Catherine
- Subjects
- *
ANALYTICAL chemistry , *BENZOIN , *GUMS & resins , *FOURIER transform spectroscopy , *LIQUID chromatography - Abstract
Abstract: Contribution of analytical chemistry to the study of styrax and benzoin botanical exudates. For several resins, gaps in botanical classification and ambiguities in their designation induce difficulties to correlate with precision botanical species and chemical composition. It is the case of balsamic resins called styrax and benzoins, for which there are important linguistic, botanical and chemical confusions. This study by Fourier Transform Infrared (FTIR) spectroscopy and High-Performance Liquid Chromatography (HPLC) of several resinous samples made it possible to specify the chemical and botanical membership of these substances at the origin of many interrogations. It also provided interesting information about the ways to obtain or to transform the resinous matters while evoking the possibility of adulterations or confusions with dammar resin issued from geographically close vegetable species. To cite this article: M. Hovaneissian et al., C. R. Chimie 9 (2006) . [Copyright &y& Elsevier]
- Published
- 2006
- Full Text
- View/download PDF
26. Identification by NMR and accumulation of a neolignan, the dehydrodiconiferyl alcohol-4-β-d-glucoside, in Linum usitatissimum cell cultures
- Author
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Attoumbre, Jacques, Hano, Christophe, Mesnard, François, Lamblin, Frédéric, Bensaddek, Lamine, Raynaud-Le Grandic, Sophie, Laine, Éric, Fliniaux, Marc-André, and Baltora-Rosset, Sylvie
- Subjects
- *
METABOLITES , *NUCLEAR magnetic resonance , *MAGNETIC resonance , *POLYMERASE chain reaction , *POLYMERIZATION - Abstract
Abstract: Phenylpropanoids represent a broad range of secondary metabolites in plants, in which they are involved in defense mechanisms. This study deals with the NMR identification of a phenylpropanoid, which belongs to the class of neolignans, dehydrodiconiferyl alcohol-4-β-d-glucoside (DCG), in in vitro cultures of Linum usitatissimum. The combination of 1- and 2-D NMR experiments such as COSY, HMBC and HMQC allowed the identification of this compound’s structure unambiguously. In order to evaluate its implication in defense mechanism, the L. usitatissimum suspension cells were placed together with fungal extracts. Consequently, the DCG concentration decreased dramatically after 96 h of treatment. In correlation, the phenylcoumaran benzylic ether reductase (PCBER) expression increased rapidly and constantly immediately after elicitation until 96 h post elicitation, as shown by semi-quantitative reverse transcriptase polymerase chain reaction (RT-PCR). These two results are in agreement, since the aglycone form of DCG is one of the two substrates of PCBER, thus suggesting PCBER activation in plant defense mechanisms. To cite this article: J. Attoumbre et al., C. R. Chimie 9 (2006) . [Copyright &y& Elsevier]
- Published
- 2006
- Full Text
- View/download PDF
27. Extraction sur phase solide et analyses par HPLC du 5-fluoro-uracile plasmatique
- Author
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Gamaoun, Saif Eddine and Saguem, Saad
- Subjects
- *
SOLID phase extraction , *EXTRACTION (Chemistry) , *EXTRACTION techniques , *HIGH performance liquid chromatography , *CHROMATOGRAPHIC analysis - Abstract
Abstract: Solid-phase extraction and analysis of 5-fluoro-uracil plasmatic by high-performance liquid chromatography. 5-Fluoro-uracil (5-FU) is an antitumoral agent widely employed in the treatement of many types of cancer. In the present study, a new reversed-phase high-performance liquid chromatography HPLC method has been developed and validated for the quantitative determination of 5-fluoro-uracil (5-FU) in human plasma. Before the chromatography, the drug (5-FU) was isolated from the plasma matrix by double extraction: liquid- and solid-phase extraction. Reversed- phase high-performance liquid chromatography was performed on a C18 column (250 mm × 4.6 mm I.D.) with a mobile phase of phosphate buffer (0.05 M, adjusted to pH 3.2) and ultraviolet detection UV (268 nm). To cite this article: S.E. Gamaoun, S. Saguem, C. R. Chimie 8 (2005) . [Copyright &y& Elsevier]
- Published
- 2005
- Full Text
- View/download PDF
28. Dosage du cortisol libre urinaire par chromatographie liquide.
- Author
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Brau, M., Banse, V., Dupret, P., Ledant, T., and Boudry, P.
- Subjects
HYDROCORTISONE ,LIQUID chromatography ,CHROMATOGRAPHIC analysis ,CHEMILUMINESCENCE ,GLUCOCORTICOIDS - Abstract
Copyright of IBS, Immuno-analyse & Biologie Specialisee is the property of Elsevier B.V. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2005
- Full Text
- View/download PDF
29. Durée de péremption des solutions de morphine et de la péthidine présentées dans des dispositifs pour analgésie autocontrôlée : étude de stabilité physicochimique et microbiologique
- Author
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Laville, I., Mercier, L., Chachaty, E., Bourget, P., and Paci, A.
- Subjects
- *
MORPHINE , *SELF medication , *PAIN management , *HYDROGEN-ion concentration - Abstract
Abstract: Morphine and meperidine in Patient-Controlled Analgesic devices are commonly used to treat chronic pain patients. These devices deliver a programmed amount of drug and allow self-administration by the patient depending on the pain. In our department of pharmacy, 300 devices were manufactured in 2003. The aim of this study was to assess their shelf-life. The devices were filled aseptically and without preservatives with 1 and 40 mg/ml morphine solution and 5 and 20 mg/ml meperidine and stored over 30 days at room temperature and protected from light. Culture assay of the solutions showed that they remained sterile for 30 days. No turbidity of any solutions from samples collected twice a week was noticed. pH and osmolarity remained constant. Drug concentrations were determined using stability indicating HPLC method, as we showed that degradation products can be separated from the drugs. Little loss of meperidine occured within 21 days (<5%) and morphine concentration, which increased, because of solvent evaporation, remained lower than 5% within 21 days but increased up to 10% after 30 days. No traces of degradation products (pseudomorphine or pethidic acid) were detected. The physicochemical and microbiological stability of morphine and meperidine hydrochlorides stored in such devices has been established for 21 days at room temperature and protected from light. [Copyright &y& Elsevier]
- Published
- 2005
- Full Text
- View/download PDF
30. Suivi thérapeutique des médicaments antifongiques.
- Author
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Blanchet, Benoît, Huet, Estelle, Astier, Alain, and Hulin, Anne
- Abstract
Copyright of Revue Francaise des Laboratoires is the property of Elsevier B.V. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2004
- Full Text
- View/download PDF
31. A facile methodology for the synthesis and detection of N7-guanine adduct of sulfur mustard as a biomarker.
- Author
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Rao, Mula Kameswara, Bhadury, Pinaki S, Sharma, Mamta, Dangi, Rajinder S, Bhaskar, Appanabhotla S, Raza, Syed K, and Jaiswal, Devendra K
- Subjects
- *
BIOMARKERS , *SPECTRUM analysis , *HIGH performance liquid chromatography , *BIOINDICATORS , *BIOCHEMISTRY - Abstract
A simple and convenient method has been developed for the synthesis of a N7-guanine adduct of sulfur mustard (SM), which can serve as an efficient biomarker for alleged exposure to SM. The adduct obtained in high yields (~78%) was characterized on the basis of its physical properties and spectral data. In addition, HPLC and LC-MS conditions have been standardized for the detection of the adduct in both in vitro and in vivo samples, which is useful for retrospective detection of exposure to SM in biological samples.Key words: sulfur mustard, biomarker, N7-guanine adduct, in vitro, in vivo, HPLC, LC-MS, electrospray, 2D NMR.On a développé une méthode simple et pratique de synthétiser l'adduit de la N7-guanine avec la moutarde au soufre (MS) qui peut servir de biomarqueur efficace dans les cas supposés d'exposition à la MS. L'adduit qui a été obtenu avec des rendements élevés (environ 78 %) a été caractérisé sur la base de données physiques et spectroscopiques. De plus, on a développé des conditions standards de chromatographie liquide à haute performance (CLHP) et de spectrométrie de masse couplée à la chromatographie liquide (SM-CL) pour la détection de l'adduit dans des échantillons in vitro ainsi que in vivo; celles-ci seront très utiles pour la détection rétrospective d'expositions à la MS dans des échantillons biologiques.Mots clés : moutarde au soufre, biomarqueur, adduit de la N7-guanine, in vitro, in vivo, CLHP, SM-CL, électronébulisation, RMN 2D.[Traduit par la Rédaction] [ABSTRACT FROM AUTHOR]
- Published
- 2002
- Full Text
- View/download PDF
32. Chemotaxonomic study and biological activity of secondary metabolites of Eryngium species
- Author
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Landoulsi, Ameni, Institut Charles Viollette (ICV) - EA 7394 (ICV), Université du Littoral Côte d'Opale (ULCO)-Université de Lille-Institut National de la Recherche Agronomique (INRA)-Université d'Artois (UA)-Institut Supérieur d'Agriculture, Université du Droit et de la Santé - Lille II, Université de Tunis El Manar, Jeannette Ben Hamida, Thierry Hennebelle, and Université d'Artois (UA)-Institut National de la Recherche Agronomique (INRA)-Université du Littoral Côte d'Opale (ULCO)-Institut Supérieur d'Agriculture-Université de Lille
- Subjects
CPG-SM ,Cytotoxic activity ,Eryngium ,Phototoxic activity ,CPC ,Antimicrobial activity ,CLHP ,Polyacétylènes ,Activité cytotoxique ,Activité phototoxique ,CG-MS ,HPLC ,Polyacetylenes ,Activité microbienne ,[SDV.MHEP]Life Sciences [q-bio]/Human health and pathology - Abstract
The genus Eryngium L., (Apiaceae, Saniculoideae) comprises more than 250 flowering plant species, which are commonly used as medicinal plants in different countries. Only eight species are growing in Tunisia: E. barrelieri Boiss., E. campestre L., E. dichotomum Desf., E. glomeratum Lamk., E. ilicifolium Lamk., E. maritimum L., E. tricuspidatum L. et E. triquetrum Vahl. These species are used in traditional medicine and there are relatively few papers on the phytochemical investigations of most of them. This study was performed on all Eryngium species growing in Tunisia in order to evaluate their chemical variability using GC-FID and GC-MS analyses and their biological activities, mainly antimicrobial against multiresistant microorganisms and extended spectrum beta-lactamase producing bacteria (ESBL), and also phototoxic and cytotoxic effects.All investigated species showed considerable antimicrobial effect with MIC value ranging between 1,25 and 0,07 mg/mL and important cytotoxic activity against J774 tumoral cells with IC50 from 24,4 to 0,32 µg/mL. Phototoxic investigation demonstrated a significant photoactive inhibitory effects against tested pathogenic microorganisms.GC–MS analysis of the most active crude extracts (petroleum ether extracts) revealed their high content of antimicrobial agents particularly oxygenated sesquiterpenes such as spathulenol, ledol, α-bisabolol and cubenol, and hydrocarbon sesquiterpenes such as β-bisabolene and copaene; and cytotoxic components such as falcarinol.The chemical investigation and bio-guided isolation of active compounds of the selected crude extract of E. triquetrum roots were performed using column chromatography, centrifugal partition chromatography (CPC) and preparative high-performance liquid chromatography (HPLC). among purified components, two bioactive polyacetylenes, panaxydiol and falcarinol, showed a great antimicrobial activity mainly against multiresistant and ESBL producing Pseudomonas aeruginosa with MIC value up to 0,25 ng/ml and a mostly bactericidal effect.; Le genre Eryngium L. (Apiaceae, Saniculoideae) comprend plus de 250 espèces utilisées en médecine traditionnelle à travers le monde. En Tunisie il existe seulement huit espèces : E. barrelieri Boiss., E. campestre L., E. dichotomum Desf., E. glomeratum Lamk., E. ilicifolium Lamk., E. maritimum L., E. tricuspidatum L. et E. triquetrum Vahl. ; ces espèces sont en majorité peu étudiées du point de vue phytochimique. La présente étude a été effectuée sur la totalité des Eryngium qui poussent en Tunisie dans le but d’évaluer leurs activités biologiques, essentiellement antimicrobienne contre des microorganismes multirésistants et producteurs de béta-lactamases à spectres étendus (BLSE), mais aussi phototoxique et cytotoxique ainsi que la variabilité chimique par analyse par GC-FID et GC-MS des extraits les plus actifs.Toutes les espèces étudiées étaient dotées d’un pouvoir antimicrobien (1,25 à 0,07 mg/mL) et cytotoxique (24,4 à 0,32 µg/mL) considérable. Le criblage de l’activité phototoxique a permis de mettre en évidence la richesse de ces plantes en composés photoréactifs antimicrobiens potentiellement intéressants pour leur efficacité d’action et l’élargissement du spectre d’activité antimicrobienne.L’analyse des extraits actifs apolaires a permis d’étudier la variabilité chimique entre les différentes espèces et la mise en évidence de la présence majoritaire de composés antimicrobiens notamment des sesquiterpènes oxygénés tels que le spathulénol, le lédol, l’α-bisabolol et le cubénol, et des sesquiterpènes hydrocarbonés comme le β-bisabolène et le copaène ; et cytotoxiques tel que le falcarinol.Une étude phytochimique approfondie a été réalisée sur les racines d’E. triquetrum afin d’extraire, isoler par des essais bio-guidés et identifier les composés actifs. Le fractionnement a été optimisé par des chromatographies sur colonnes, CPC et CLHP. Parmi les composés identifiés deux polyacétylènes, le panaxydiol et le falcarinol, ont montré un fort pouvoir antimicrobien et une spécificité d’action notamment contre les souches de Pseudomonas aeruginosa BLSE et multirésistantes, avec des CMI allant jusqu’à 0,25 ng/mL et une activité en majorité bactéricide.
- Published
- 2016
33. Novel bio-analytical technique for estimation of gamma oryzanol in rat plasma and brain homogenate using HPLC.
- Author
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Singh S, Kothari C, Patel M, and Panchal S
- Subjects
- Animals, Chromatography, High Pressure Liquid, Freezing, Limit of Detection, Quality Control, Rats, Reproducibility of Results, Solvents, Spectrophotometry, Ultraviolet, Tandem Mass Spectrometry, Brain Chemistry, Phenylpropionates blood
- Abstract
Gamma oryzanol, a component of rice bran oil is used for its anticancer and antihyperlipidemic properties. Bioanalytical method for rat plasma and brain homogenate was developed by HPLC system with a PDA detector in which drug elution was performed using C-18 column (4.6mm×150cm, 5μ) with 1% acetic acid in methanol: acetonitrile (65/35, v/v) as mobile phase at 1.2ml/min flow rate and detected at 326nm wavelength. Liquid liquid extraction method was chosen for extraction of oryzanol from plasma as well as brain homogenate as it provided highest recovery (95% in plasma, 85% in brain homogenate). Various extraction solvents for each body fluid were analysed, out of which highest recovery for plasma (95%), in acetone: IPA (1/1, v/v) and for brain homogenate (85%) in isopropyl alcohol (IPA) was observed. Observed linearity was between 500ng/mL-5000ng/mL. The interday and intraday precision (i.e. %RSD) was less than 10% and accuracy was±5%. Selectivity and matrix effect was checked and found as per USFDA criteria. Plasma samples were found to be stable over the analysis period, HQC samples were stable up to third cycle in freeze and thaw stability while LQC samples were stable over fourth cycle. The method proved to be simple, useful and is appropriate, for preclinical and experimental research., (Copyright © 2020 Académie Nationale de Pharmacie. Published by Elsevier Masson SAS. All rights reserved.)
- Published
- 2020
- Full Text
- View/download PDF
34. Adsorption et dénaturation des protéines dans des dispositifs injectables pour des applications pharmaceutiques
- Author
-
Huang, Tongtong, Institut de Science des Matériaux de Mulhouse (IS2M), Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Matériaux et nanosciences d'Alsace (FMNGE), Institut de Chimie du CNRS (INC)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Réseau nanophotonique et optique, Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA), Université de Haute Alsace - Mulhouse, and Karine Anselme
- Subjects
Adsorption des protéines ,Chromatography ,Spectroscopie infrarouge à transformée de Fourier ,Structure des protéines ,Protein adsorption ,Protein quantification ,[CHIM.MATE]Chemical Sciences/Material chemistry ,CLHP ,[CHIM.INOR]Chemical Sciences/Inorganic chemistry ,Protein denaturation ,Dénaturation des protéines ,Quantification des protéines ,Chromatographie ,Réflectance totale atténuée ,Protein structure ,Stabilité des protéines pendant le stockage à long terme ,HPLC ,ATR-FTIR ,Protein stability during long-term storage - Abstract
Proteins are widely used in formulation in the pharmaceutical field and play a major role in biological functions. It is well known that protein adsorption on solid surface is always observed for a long-term storage, which will result in a reduced dose of active compound or a loss of biological activity. In some cases, only short time of contact are sufficient to drastically modify the protein conformation: for instance, insulin losses 52% of its biological activity after 5 minutes contacting with glass surface, as well as a loss of 30% of cetrorelix is observed after 2 hours. Among all parameters, the time frame of the denaturation process is strongly related to the protein stability and surface properties. The understanding of protein adsorption has therefore become a crucial issue in the pharmaceutical industry.To gain a better understanding of proteins’ behavior on the surface, adsorbed protein quantification and its conformation should be studied. The objective of our research in a first will be to understand proteins’ behaviors on various surfaces which composed a classical prefilled syringe.The main goal of this PhD project is to understand the behaviors of several model proteins like bovine serum albumin (BSA), lysozyme (LSZ) and myoglobin (MGB) in contact with the surfaces of prefilled syringes such as glass and elastomer. We propose to use the high performance liquid chromatography (HPLC) to quantify the amount of protein adsorbed on a flat surface by determining the depletion of the proteins in solution. Fourier transform infrared-attenuated total reflection (FTIR-ATR) spectroscopy was as well as employed to follow the structural changes of adsorbed BSA on solid surface. [...]; Protéines sont largement utilisés dans la formulation dans le domaine pharmaceutique et de jouer un rôle important dans les fonctions biologiques. Il est bien connu que l'adsorption de protéines sur la surface solide est toujours observé pour un stockage à long terme, ce qui entraînera une réduction de la dose de substance active ou une perte de l'activité biologique. Dans certains cas, une courte période de contact avec la surface est suffisante pour modifier fortement la conformation des protéines : par exemple, l'insuline pertes 52% de son activité biologique après 5 minutes de contact avec la surface de verre, ainsi qu'une perte de 30% d’activité biologique du cétrorélix est observé après 2 heures de contact. Parmi tous les paramètres, la dénaturation des protéines est fortement liée à sa stabilité des propriétés de surface. La compréhension de l'adsorption de protéines est devenue une question cruciale dans l'industrie pharmaceutique.Pour mieux comprendre le comportement des protéines à la surface, la quantification des protéines adsorbées et sa conformation devrait être étudiée. L'objectif de notre recherche sera de comprendre les comportements des protéines sur différents surfaces de seringue pré - remplie classique.Le principal objectif de ce projet est de comprendre le comportement de plusieurs modèles de protéines comme la sérum d’albumine bovine (BSA), le lysozyme (LSZ) et la myoglobine (MGB) en contact avec des surfaces de seringues pré-remplie comme le verre et l’élastomère. Nous proposons d'utiliser la chromatographie liquide à haute performance (HPLC) pour la quantification de protéine adsorbée sur une surface plane en déterminant la déplétion des protéines en solution. La réflexion totale atténuée infrarouge à transformée de fourier (FTIR-ATR) spectroscopie est utilisée de suivre les changements structurels des protéines adsorbées sur des surfaces solides. [...]
- Published
- 2016
35. Review of physicochemical-based diagnostic techniques for assessing insulation condition in aged transformers
- Author
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N'cho, Janvier Sylvestre, Fofana, Issouf, Hadjadj, Yazid, Beroual, Abderrahmane, N'cho, Janvier Sylvestre, Fofana, Issouf, Hadjadj, Yazid, and Beroual, Abderrahmane
- Abstract
A power transformer outage has a dramatic financial consequence not only for electric power systems utilities but also for interconnected customers. The service reliability of this important asset largely depends upon the condition of the oil-paper insulation. Therefore, by keeping the qualities of oil-paper insulation system in pristine condition, the maintenance planners can reduce the decline rate of internal faults. Accurate diagnostic methods for analyzing the condition of transformers are therefore essential. Currently, there are various electrical and physicochemical diagnostic techniques available for insulation condition monitoring of power transformers. This paper is aimed at the description, analysis and interpretation of modern physicochemical diagnostics techniques for assessing insulation condition in aged transformers. Since fields and laboratory experiences have shown that transformer oil contains about 70% of diagnostic information, the physicochemical analyses of oil samples can therefore be extremely useful in monitoring the condition of power transformers.
- Published
- 2016
36. Trigonelline and sucrose diversity in wild Coffea species
- Author
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J.F. Ballester, Claudine Campa, Sylvie Doulbeau, Stéphane Dussert, Serge Hamon, and Michel Noirot
- Subjects
Sucrose ,Canephora ,DIVERSITE SPECIFIQUE ,CLHP ,SUCRE ,Coffea canephora ,Analytical Chemistry ,chemistry.chemical_compound ,Trigonelline ,Botany ,CAFE ,SUCROSE ,Aroma ,TRIGONELLINE ,Rubiaceae ,BIOCHIMIE ,biology ,Coffea arabica ,Coffea ,CAFEIER ,General Medicine ,biology.organism_classification ,chemistry ,PLANTE SAUVAGE ,ALCALOIDE ,Food Science - Abstract
Trigonelline and sucrose are two coffee aroma precursors. Contents of these compounds are higher in Coffea arabica than in Coffea canephora green beans and this could be the main explanation for consumers' preference for C. arabica coffee. This is the first evaluation of sucrose and trigonelline contents involving 14 species and six new taxa not yet botanically characterised. Trigonelline and sucrose contents varied between species from 0.39% to 1.77% dry matter basis (dmb) and from 3.8% to 10.7% dmb, respectively. C. canephora could be improved through both compounds by crosses with Coffea eugenioides.
- Published
- 2004
- Full Text
- View/download PDF
37. Caractérisation chimique d'une résine naturelle en Égypte ancienne : application à un exemple de la collection Victor Loret
- Author
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Paul Archier, Catherine Vieillescazes, Gérald Culioli, and Carole Mathe
- Subjects
General Energy ,natural resin ,HPLC ,fluorimetry ,terpènes ,7-oxodehydroabietic acid ,retene ,frankincense ,egyptology ,media_common.quotation_subject ,fluorimétrie ,résine naturelle ,égyptologie ,CLHP ,oliban ,rétène ,acide 7-oxodéhydroabiétique ,Pine tree ,Natural resin ,Art ,Humanities ,media_common - Abstract
L41 is a sample of Victor Loret's collection from the Egyptologic Institute (Lyon II University, Pr. J.-C. Goyon). It was recovered from excavations at Dashour in 1894-1 895 by the archaeologist J. de Morgan. It comes from a flask of princess Sat-mer-hout's funeral endowment (XIIth dynasty). As written, it may be a ritual fragance or, at least, an artificial composition. This material was analysed by HPLC (High Performance Liquid Chromatography) with a double detection (PDA/ fluorimetry) and the result show a mixture of two natural plant resins : a diterpenic pine resin and a triterpenic one to frankincense (Burseraceae family, Boswellia genus)., L'échantillon L41 provient de la collection Victor Loret de l'Institut d'Egyptologie (Université Lyon II, Pr J.-C. Goyon). Il a été prélevé lors des fouilles que l'archéologue J. de Morgan effectua sur le site de Dashour dans les années 1 894 et 1 895. Ce prélèvement est issu de la dotation funéraire de la princesse Sat-mer-hout (XIIème dynastie) ; la suscrip- tion du flacon d'où fut tiré L41 évoque la possibilité d'un parfum rituel ou du moins d'une composition artificielle. L'analyse du matériau menée par Chromatographie Liquide à Haute Performance (CLHP) équipée d'une double détection barrette de photodiodes/fluorimétrie met en évidence l'existence d'un mélange d'au moins deux résines végétales l'une diterpénique appartenant à la famille des Pinacées, l'autre de nature triterpénique correspondant à de l'oliban (encens véritable, famille des Burséracées)., Mathe Carole, Archier Paul, Culioli Gérald, Vieillescazes Catherine. Caractérisation chimique d'une résine naturelle en Égypte ancienne : application à un exemple de la collection Victor Loret.. In: Revue d'Archéométrie, n°27, 2003. pp. 43-47.
- Published
- 2003
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38. A versatile HPLC method with an isocratic single mobile phase system for simultaneous determination of anti-glaucoma formulations containing timolol.
- Author
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Ibrahim FA, Elmansi HM, and El Abass SA
- Subjects
- Brimonidine Tartrate analysis, Chromatography, High Pressure Liquid, Drug Combinations, Drug Compounding, Limit of Detection, Ophthalmic Solutions, Reference Standards, Reproducibility of Results, Sulfonamides analysis, Thiazines analysis, Thiophenes analysis, Adrenergic beta-Antagonists analysis, Glaucoma drug therapy, Timolol analysis
- Abstract
Timolol is a non-cardioselective beta blocker and has different combined ophthalmic dosage forms for treatment of glaucoma. This research introduce an HPLC method for the separation of three drugs used in combination with timolol simultaneously by applying isocratic mobile phase system in a single run and the same detection wavelength with short time. The drugs included in the separation procedures are; dorzolamide, brinzolamide, and brimonidine. The HPLC method was carried out through a single mobile phase system, which contains acetonitrile: 0.05M phosphate buffer at the ratio of 30:70, respectively at pH 3.5 and wavelength of 220nm. The method, regarding its simplicity allows determination of the studied drugs simultaneously using single run in about 8minutes. The method was rectilinear in the ranges of concentration: 1.25-25μg/mL for timolol, 4-80μg/mL for dorzolamide, 5-50μg/mL for brinzolamide and 2-20μg/mL for brimonidine. Different factors affecting the separation are thoroughly studied. The developed method was validated based on the official guidelines and the results were compared statistically with previously published methods and showed non-significant difference., (Copyright © 2019 Académie Nationale de Pharmacie. Published by Elsevier Masson SAS. All rights reserved.)
- Published
- 2019
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39. Development of a new liquid chromatographic method for the simultaneous separation of ciprofloxacin degradation products with 5-hydroxymethyl-furfural, impurity of D-glucose, in an intravenous solution for perfusion.
- Author
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Louati K, Mlouka M, and Safta F
- Subjects
- Chromatography, High Pressure Liquid, Furaldehyde analysis, Indicators and Reagents, Limit of Detection, Perfusion, Reproducibility of Results, Sensitivity and Specificity, Spectrophotometry, Ultraviolet, Temperature, Anti-Bacterial Agents analysis, Ciprofloxacin analysis, Drug Contamination, Furaldehyde analogs & derivatives, Glucose analysis, Pharmaceutical Solutions analysis
- Abstract
The place occupied by fluoroquinolones is very important clinically. Ciprofloxacin has been the most widely prescribed one which exhibits good activity against Pseudomonas aeruginosa and Acinetobacter. D-glucose is frequently used as an excipient in most formulations for perfusion solutions. Since there is much interest in pharmaceutical quality control of such formulations, separation of impurities from the main drug substances and accurate assay quantification, and since there is no reference or monograph until nowadays that has been reported for the simultaneous separation of ciprofloxacin degradation products along with 5-hydroxymethyl-furfural (5-HMF), impurity of D-glucose, classified as a high toxic substance, thus our aim of this work is to develop a new simple, sensitive and stability indicating method allowing this separation by high-performance liquid chromatography. We have started from the chromatographic conditions recommended by the British Pharmacopoeia, and by optimizing the nature of the stationary phase, the composition of the mobile phase and the injection volume. After optimisation, the retained chromatographic conditions have enabled the separation of all impurities with good resolution factor greater than 1.5 for each pair of peaks and with good symmetry peak shape. The developed method was validated according to the International Conference of Harmonisation (ICH) guidelines for specificity, detection and quantification limits, and then it was applied to stability study of the formulation subjected to different ICH prescribed stress conditions. The 5-HMF was checked to be the impurity issued from D-glucose hydrolysis by high temperature mainly after autoclaving of pharmaceuticals. The developed method was proved to be simple, specific with very low limit of quantification. Hence, it can be considered as a method for stability indicating and routine quality control analysis in pharmaceutical industries., (Copyright © 2018 Académie Nationale de Pharmacie. Published by Elsevier Masson SAS. All rights reserved.)
- Published
- 2019
- Full Text
- View/download PDF
40. Les stilbénoïdes chez les Cypéracées : isolation, identification et étude de leurs activités biologiques : identification et dosage des stilbènes dans des vins Tunisiens
- Author
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Arraki, Kamel and STAR, ABES
- Subjects
LC-Masse ,CPC ,CLHP ,NMR ,RMN ,Β-amyloïde ,[SDV.AEN] Life Sciences [q-bio]/Food and Nutrition ,Β-amyloid ,Vin tunisien ,Tunisian wine ,Cypéracées ,ORAC ,Cyperaceae ,Carexinol ,HPLC ,Stilbènes ,LC-Mass ,DPPH - Abstract
Stilbenes are phenolic compounds of plant secondary metabolism, whosedistribution within the plant kingdom is limited to species that have acquired during theevolution the ability to synthesize these molecules. Their impacts and their biologicalactivities such as neuroprotective, anticarcinogenic, antioxidant effects have already touchedseveral topics. It is in this context that the purpose of our work arose. First, we have isolatedand identified these molecules in some species of the sedge family. Phytochemical studieswere performed using a set of analytical and preparative strategies by means of analytical andpreparative HPLC and CPC (Centrifugal Partition Chromatography) for obtaining puremolecules and LC-Mass and NMR for identification of compound isolated. In a second step,we investigated the in vitro biological properties of these products such as antioxidantactivities by three methods (ORAC, DPPH and MCA) and their effect on neuronalcytotoxicity induced by β-amyloid peptide with PC12 cells. We isolated a new molecule, forthe first time, carexinol A, that showed strong anti-amyloid activity. The last part of this thesisrefers to the analysis and determination of stilbenes in Tunisian wines including Sidi Zahiawine that gave the best results., Les stilbènes sont des composés phénoliques issus du métabolisme secondairevégétal, dont la distribution au sein du règne végétal est limitée aux espèces qui ont acquis aucours de l’évolution la capacité à synthétiser ces molécules. Leurs impacts et leurs activitésbiologiques tels que les effets neuroprotecteurs, anticancérigènes, antioxydants ont déjàconcerné plusieurs sujets d’étude. C’est dans ce contexte que l’objectif de notre travail a prisnaissance. Dans un premier temps, nous avons isolé et identifié ces molécules chez quelquesespèces de la famille des Cypéracées. Cette étude phytochimique a été réalisée en utilisant unensemble de stratégies analytiques et préparatives faisant appel à la CLHP analytique etpréparative et la CPC (Chromatographie de Partage Centrifuge) pour l’obtention desmolécules pures et à la LC-Masse et la RMN pour l’identification des composées isolés. Dansun second temps, nous avons étudié les activités biologiques in vitro de ces produits telles queles activités antioxydantes par trois méthodes (ORAC, DPPH et MCA) et l’effet de cesstilbènes sur la cytotoxicité neuronale induite par le peptide β-amyloïde avec des cellulesPC12. Nous avons isolé une nouvelle molécule, le carexinol A, pour la première fois, qui amontré une forte activité anti-amyloïde. La dernière partie de cette thèse fait état de l’analyseet du dosage des stilbènes dans des vins tunisiens dont le vin Sidi Zahia qui a donné lesmeilleurs résultats.
- Published
- 2014
41. Identification of the carotenoid pigment canthaxanthin from photosynthetic bradyrhizobium strains
- Author
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Flore Molouba, Jean Lorquin, and Bernard Dreyfus
- Subjects
PIGMENT ,EXTRACTION ,Rhizobiaceae ,medicine.medical_treatment ,Orange (colour) ,CLHP ,Applied Microbiology and Biotechnology ,Bradyrhizobium ,Pigment ,chemistry.chemical_compound ,Botany ,medicine ,Food science ,Canthaxanthin ,Carotenoid ,chemistry.chemical_classification ,Ecology ,biology ,Carotene ,food and beverages ,Aeschynomene ,biology.organism_classification ,CAROTENOIDE ,NODULE CAULINAIRE ,chemistry ,visual_art ,IDENTIFICATION DE SUBSTANCE CHIMIQUE ,visual_art.visual_art_medium ,CHROMATOGRAPHIE ,sense organs ,Research Article ,Food Science ,Biotechnology - Abstract
Canthaxanthin (4,4(prm1)-diketo-(beta)-carotene) is produced as the major carotenoid pigment by orange- and dark-pink-pigmented bacteriochlorophyll-containing Bradyrhizobium strains isolated from stem nodules of Aeschynomene species. These two new pigmentation groups differ from the well-studied strain BTAi1, which accumulates spirilloxanthin as the sole carotenoid.
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- 1997
- Full Text
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42. Complexation of pentacyclic triterpenes by cyclodextrines : physicochemical characterization and biological activities
- Author
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Fontanay, Stéphane, Structure et Réactivité des Systèmes Moléculaires Complexes (SRSMC), Institut de Chimie du CNRS (INC)-Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS), Université de Lorraine, Francine Kedzierewicz, Raphaël Emmanuel Duval, and UL, Thèses
- Subjects
anticancerous) ,[SDV.MHEP] Life Sciences [q-bio]/Human health and pathology ,H1-RMN ,Anticancéreux ,Activités anti-infectieuses ,Triterpènes ,Hydroxy pentacyclic triterpene acids (HPTAs) ,CLHP ,Antiinfectieux ,DSC ,[CHIM.OTHE] Chemical Sciences/Other ,Composés complexes-Solubilité ,Gamma-cyclodextrine ,Complexation ,Analytical techniques (HPLC ,AHPTS ,Cyclodextrines ,[CHIM.OTHE]Chemical Sciences/Other ,H1-MNR) ,ACD ,Biological activities (anti-infectious ,[SDV.MHEP]Life Sciences [q-bio]/Human health and pathology ,Activités anticancéreuses - Abstract
The lack of innovative therapies in human chemotherapy incites the scientific community to be interested in new sources of bioactive compounds. We can quote the secondary metabolites of plants, to which belong hydroxy pentacyclic triterpene acids (HPTAs) and more particularly Ursolic (UA), Oleanolic (OA) and Betulinic Acids(BA). These molecules are the subjetc of numerous studies which tend to demonstrate their properties: anti-infective, anticancer, antiproliferatives, anti-inflammatory and hepatoprotectrive. The main obstacle to their use in therapeutic purposes stays the insolubility of these AHPTs in the water. Thus the objective of this work was to increase their hydrosolubility. At first, in agreement with the recommendations and/or the existing standards, we demonstrated that the antibacterial spectra of UA and OA are limited to Gram-positive bacteria. No HPTA showed antifungal activity. Only the BA showed an interesting antiviral activity on human Cytomegalovirus (hCMV); no antiviral activity was on Poliovirus. Finally, the BA, but even more UA showed an anticancer activity against cellular model of chronic myeloid leukemia (CML). Secondly, we proceeded to the manufacturing and to the study of complexes between HPTAs and cyclodextrines. We retained gamma-cyclodextrine (gamma-CD), which presented the advantage to complex the 3 AHPTs with a constant of "average" to "raised". These HPTAs:gamma-CD complexes were characterized by using diverse techniques: chromatographic, thermal and spectrometric. We concluded in the obtaining of inclusion complexes which allowed increasing the solubility of the HPTAs. In a last part, we estimated the biological activities of the HPTAs:gamma-CD complexes. The results show that the UA:gamma-CD and OA:gamma-CD complexes remain active against Gram-positive bacteria (but with a weaker efficiency); whereas the BA:gamma-CD complex shows to be active on certain bacteria. The BA:gamma-CD complex, and in a surprising way the UA:gamma-CD complex presents an antiviral activity against the hCMV. Finally, the decrease of the cytotoxicity linked to the complexation of the HPTAs believes the interest of UA and of BA on CML cells, Le manque de thérapies innovantes en chimiothérapie humaine incite la communauté scientifique à s'intéresser à de nouvelles sources de composés bioactifs. Nous pouvons citer les métabolites secondaires de plantes, auxquels appartiennent les acides hydroxy pentacycliques triterpénoiques (AHPTs) et plus particulièrement les Acides Ursolique (AU), Oléanolique (AO) et Bétulinique (AB). Ces molécules font l'objet de nombreuses études qui tendent à démontrer leurs propriétés : anti-infectieuses, anticancéreuses, antiprolifératives, anti-inflammatoires, hépatoprotectrices. Le principal obstacle à leur utilisation à des fins thérapeutiques, reste l'insolubilité de ces AHPTs dans l'eau. L'objectif de ce travail a donc été d'augmenter leur hydrosolubilité. Dans un premier temps, en accord avec les recommandations et/ou normes existantes, nous avons démontré que le spectre d'activité antibactérienne de l'AU et de l'AO se limitait aux bactéries à Gram positif. Aucun AHPT n'a montré d'activité antifongique. Seul l'AB a montré une activité intéressante sur le Cytomégalovirus humain (hCMV) ; aucune activité antivirale n'ayant été retrouvée sur le Poliovirus. Enfin, l'AB, mais encore plus l'AU ont montré une activité anticancéreuse à l'encontre de cellules modèles de leucémie myéloïde chronique (LMC). Dans un deuxième temps, nous avons procédé à la fabrication et à l'étude de complexes entre les AHPTs et des cyclodextrines. Nous avons retenu la gamma-cyclodextrine (gamma-CD), qui présentait l'avantage de complexer les 3 AHPTs avec une constante de formation « moyenne » à « élevée ». Ces complexes AHPTs :gamma-CD ont été caractérisés en utilisant diverses techniques : chromatographiques, thermiques et spectrométriques. Nous avons conclu à l'obtention de complexes d'inclusion qui ont permis d'augmenter la solubilité des AHPTs. Dans une dernière partie, nous avons évalué les activités biologiques des complexes AHPTs : gamma-CD. Les résultats montrent que les complexes AU : gamma-CD et AO : gamma-CD restent actifs à l'encontre des bactéries à Gram positif (mais avec une efficacité plus faible) ; tandis que le complexe AB : gamma-CD se révèle être actif sur certaines bactéries. Le complexe AB : gamma-CD, et de façon surprenante le complexe AU : gamma-CD présentent une activité antivirale à l'encontre du hCMV. Enfin, la diminution de la cytotoxicité liée à la complexation des AHPTs accroit l'intérêt des molécules d'AU et d'AB sur les cellules de LMC
- Published
- 2012
43. Production of rotenoids by heterotrophic and photomixotrophic cell cultures of tephrosia vogelii
- Author
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Hervé Chrestin, Marie-France Trouslot, Nadine Lambert, and Claudine Nef-Campa
- Subjects
CULTURE IN VITRO ,HETEROTROPHIE ,ROTENOIDE ,INSECTICIDE NATUREL ,CULTURE CELLULAIRE ,Plant Science ,CLHP ,Horticulture ,Biochemistry ,Rotenoid ,chemistry.chemical_compound ,PLANTE TROPICALE ,Botany ,PRINCIPE ACTIF ,Molecular Biology ,Tephrosia vogelii ,BIOTECHNOLOGIE ,CHROMATOGRAPHIE EN PHASE LIQUIDE ,biology ,Phenylpropanoid ,Tephrosia ,Tephrosin ,General Medicine ,Rotenone ,biology.organism_classification ,PHOTOMIXOTROPHIE ,chemistry ,Cell culture ,Deguelin ,METHODOLOGIE - Abstract
Les roténoïdes, composés dérivés de la voie du métabolisme phénylpropanoïde, sont en grande partie accumulés dans les feuilles de "Tephrosia vogelii$. Des cultures de suspensions cellulaires hétérotrophes et photomixotrophes de cette plante tropicale ont été obtenues. Les lignées cellulaires sont toutes deux capables de produire des roténoïdes, mais une production spéciale est observée dans chaque type de culture cellulaire. La lignée cellulaire photomixotrophe accumulait de la roténone et de la dégueline, et la lignée cellulaire hétérotrophe produisait essentiellement de la dégueline et de la téphrosine. (Résumé d'auteur)
- Published
- 1993
- Full Text
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44. Calixarènes et composés apparentés à propriétés anti-infectieuses
- Author
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Massimba Dibama, Hugues, Structure et Réactivité des Systèmes Moléculaires Complexes (SRSMC), Institut de Chimie du CNRS (INC)-Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS), Université Henri Poincaré - Nancy 1, Jean Bernard Regnouf De Vains, and Igor Clarot
- Subjects
Anti-infectious ,Composés hétérocycliques ,CLHP ,Anti-infectieux ,Antiinfectieux ,Guanidinium ,Prodrogue ,Release ,Calixarene ,Benzene ring ,Heterocyclic compounds ,HPLC ,Calixarènes ,Prodrug ,[CHIM.OTHE]Chemical Sciences/Other ,Libération - Abstract
The main objective of this work is based on the search and the development of new antibacterial compounds able to interact with a bacterial wall. The proposed compounds are of polycationic nature, elaborated on calixarene structure or an aromatic platform and containing guanidinium functions in various number and position. Some of them were developed as water-soluble prodrugs of the quinolone: nalidixic acid. The chapter I talk about introduction and a bibliographical study on calixarenes and their applications in biology. The chapter II presents the results obtained for the synthesis, the characterization of the partially substituted analogues of the tétra-para (guanidinoéthyl) calix[4]arene. The objective of this part is to understand the role and the importance of the number and the positioning of the guanidines functions on the calixarene core. In chapter III, are presented the various steps leading to the synthesis, the characterization and the evaluation by HPLC ways of new water-soluble prodrugs. The work is centered on a set of ionic derivatives of calix[4]arenes carriers of nalidixic acid. The prodrug behavior was demonstrated for one of them. The chapter IV presents the syntheses and characterizations of star-like poly-ionic structures are described, based on a benzene core, including a variable number of para (guanidinoéthyl) phényléther subunits. The chapter V is dedicated to the results of the biological evaluations of all the structure synthetized. For some compounds, viability and cellular toxicity were evaluated on eukaryotic cells. We show that many of the new prepared derivatives, prodrugs or not, present very interesting anti-bacterial activities; L'objet de ce travail repose sur la recherche, le développement de nouveaux composés antibactériens, devant, selon le concept initial, interagir avec la paroi bactérienne. Ces derniers sont de nature polycationique, intégrant sur une structure calixarènique tridimensionnelle ou aromatique plan, des fonctions guanidiniums en nombre variable. Certains ont été développés en tant que prodrogues hydrosolubles, capables de libérer in vivo un principe actif (acide nalidixique). Le chapitre I porte sur introduction, l'étude bibliographique des calixarènes et leurs applications en biologie. Dans chapitre II, nous présentons les résultats (synthèse et caractérisation) obtenus pour les parents partiellement substitués du tétra-para-(guanidinoéthyl)calix[4]arène. Le but de ces synthèses est d'appréhender le rôle, l'importance du nombre et le positionnement des fonctions guanidines sur le calixarène. Nous abordons au chapitre III, les différentes étapes de synthèse, de caractérisation et l'évaluation par CLHP de nouvelles prodrogues hydrosolubles. Le comportement de prodrogue potentiel est ainsi démontré pour l'un d'entre eux. Dans le quatrième chapitre sont décrites les synthèses et caractérisations de nouvelles structures poly-ioniques, intégrant un motif central de type benzène, porteur d'un nombre variable de motifs latéraux para-(guanidinoéthyl)phényléther, et conçues comme une alternative aux calixarènes précédemment développés. Le chapitre V est dédié aux résultats des évaluations biologiques de l'ensemble de ces composés. Nous montrons que plusieurs des dérivés préparés, prodrogues ou non, présentent une activité anti-bactérienne très intéressante
- Published
- 2010
45. Calixarenes and similar compounds displaying anti-infective properties
- Author
-
Massimba Dibama, Hugues, UL, Thèses, Structure et Réactivité des Systèmes Moléculaires Complexes (SRSMC), Institut de Chimie du CNRS (INC)-Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS), Université Henri Poincaré - Nancy 1, Jean Bernard Regnouf De Vains, and Igor Clarot
- Subjects
Anti-infectious ,Composés hétérocycliques ,CLHP ,Anti-infectieux ,Antiinfectieux ,Guanidinium ,Prodrogue ,[CHIM.OTHE] Chemical Sciences/Other ,Release ,Calixarene ,Benzene ring ,Heterocyclic compounds ,HPLC ,Calixarènes ,[CHIM.OTHE]Chemical Sciences/Other ,Prodrug ,Libération - Abstract
The main objective of this work is based on the search and the development of new antibacterial compounds able to interact with a bacterial wall. The proposed compounds are of polycationic nature, elaborated on calixarene structure or an aromatic platform and containing guanidinium functions in various number and position. Some of them were developed as water-soluble prodrugs of the quinolone: nalidixic acid. The chapter I talk about introduction and a bibliographical study on calixarenes and their applications in biology. The chapter II presents the results obtained for the synthesis, the characterization of the partially substituted analogues of the tétra-para (guanidinoéthyl) calix[4]arene. The objective of this part is to understand the role and the importance of the number and the positioning of the guanidines functions on the calixarene core. In chapter III, are presented the various steps leading to the synthesis, the characterization and the evaluation by HPLC ways of new water-soluble prodrugs. The work is centered on a set of ionic derivatives of calix[4]arenes carriers of nalidixic acid. The prodrug behavior was demonstrated for one of them. The chapter IV presents the syntheses and characterizations of star-like poly-ionic structures are described, based on a benzene core, including a variable number of para (guanidinoéthyl) phényléther subunits. The chapter V is dedicated to the results of the biological evaluations of all the structure synthetized. For some compounds, viability and cellular toxicity were evaluated on eukaryotic cells. We show that many of the new prepared derivatives, prodrugs or not, present very interesting anti-bacterial activities, L'objet de ce travail repose sur la recherche, le développement de nouveaux composés antibactériens, devant, selon le concept initial, interagir avec la paroi bactérienne. Ces derniers sont de nature polycationique, intégrant sur une structure calixarènique tridimensionnelle ou aromatique plan, des fonctions guanidiniums en nombre variable. Certains ont été développés en tant que prodrogues hydrosolubles, capables de libérer in vivo un principe actif (acide nalidixique). Le chapitre I porte sur introduction, l'étude bibliographique des calixarènes et leurs applications en biologie. Dans chapitre II, nous présentons les résultats (synthèse et caractérisation) obtenus pour les parents partiellement substitués du tétra-para-(guanidinoéthyl)calix[4]arène. Le but de ces synthèses est d'appréhender le rôle, l'importance du nombre et le positionnement des fonctions guanidines sur le calixarène. Nous abordons au chapitre III, les différentes étapes de synthèse, de caractérisation et l'évaluation par CLHP de nouvelles prodrogues hydrosolubles. Le comportement de prodrogue potentiel est ainsi démontré pour l'un d'entre eux. Dans le quatrième chapitre sont décrites les synthèses et caractérisations de nouvelles structures poly-ioniques, intégrant un motif central de type benzène, porteur d'un nombre variable de motifs latéraux para-(guanidinoéthyl)phényléther, et conçues comme une alternative aux calixarènes précédemment développés. Le chapitre V est dédié aux résultats des évaluations biologiques de l'ensemble de ces composés. Nous montrons que plusieurs des dérivés préparés, prodrogues ou non, présentent une activité anti-bactérienne très intéressante
- Published
- 2010
46. The role of glycosides in the light-stabilization of 3-hydroxyflavone (flavonol) dyes as revealed by HPLC
- Author
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José Luis Cabrera, Dominique Cardon, Richard A. Laursen, Xian Zhang, Department of Chemistry, Boston University, Boston University [Boston] (BU), Histoire, Archéologie et Littératures des mondes chrétiens et musulmans médiévaux (CIHAM), École normale supérieure de Lyon (ENS de Lyon)-Université Lumière - Lyon 2 (UL2)-École des hautes études en sciences sociales (EHESS)-Université Jean Moulin - Lyon 3 (UJML), Université de Lyon-Université de Lyon-Avignon Université (AU)-Centre National de la Recherche Scientifique (CNRS), Cardon, Dominique, and École normale supérieure - Lyon (ENS Lyon)-Université Lumière - Lyon 2 (UL2)-École des hautes études en sciences sociales (EHESS)-Université Jean Moulin - Lyon 3 (UJML)
- Subjects
Flaveria ,Reseda luteola ,[CHIM.ANAL] Chemical Sciences/Analytical chemistry ,Flavonoid ,CLHP ,010402 general chemistry ,3-Hydroxyflavone ,01 natural sciences ,Analytical Chemistry ,Rutin ,chemistry.chemical_compound ,dye analysis ,spectrometrie de masse ,[CHIM.ANAL]Chemical Sciences/Analytical chemistry ,analyse de colorants ,Glycoside hydrolase ,mass spectrometry ,chemistry.chemical_classification ,Sophora japonica ,Chromatography ,biology ,Chemistry ,010401 analytical chemistry ,Glycoside ,biology.organism_classification ,0104 chemical sciences ,Glycosidase ,[SHS.HIST] Humanities and Social Sciences/History ,HPLC ,Quercetin ,[SHS.HIST]Humanities and Social Sciences/History - Abstract
Before the advent of synthetic dyes, textiles were colored primarily with extracts of plants, many of which, in the case of yellow colors, were flavonoids. One important Asian yellow dye source was buds from the pagoda tree (Sophora japonica). Using reversed phase HPLC to separate the flavonoid components of plants and of dyed textiles, and UV/Visible and mass spectrometry to detect and identify them, we have shown that the buds of pagoda trees (Sophora japonica) contain an enzyme that converts light-stable rutin, the 3-O-rutinoside of quercetin, to light-unstable quercetin. This work provides an explanation for why 3-O-substituted, rather than unsubstituted, 3-hydroxyflavones, are generally, in our experience, found in extracts of historical textiles; it also shows how, i.e., by heat inactivation of glycosidases, 3-O-substituted hydroxyflavones could have been selected for. Some other dyeproducing plants, e.g., Reseda luteola and Flaveria haumanii, also appear to contain glycosidases. The need for proper processing of dyestuffs, e.g., by heat treatment, was probably recognized by dyers in ancient times, even if the processes were not understood., Analyses et discussion sur la composition chimique et les solidités lumière relatives de plantes à colorants jaunes flavonoïdes d'importance historique.
- Published
- 2010
47. Incidence of Fusarium species and levels of fumonisin B1in corn in the Samsun province of Turkey
- Author
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Gulay Altiparmak, Berna Tunali, OMÜ, and Ondokuz Mayıs Üniversitesi
- Subjects
Fusarium ,mycotoxines ,Veterinary medicine ,Social Sciences and Humanities ,F. verticillioides ,Plant Science ,CLHP ,F. Verticillioides ,chemistry.chemical_compound ,mycotoxins ,Fumonisin ,Botany ,Cultivar ,F. Subglutinans ,Fumonisin B1 ,biology ,Fusarium proliferatum ,F. subglutinans ,Incidence (epidemiology) ,Contamination ,Mycotoxins ,biology.organism_classification ,chemistry ,Preharvest ,Sciences Humaines et Sociales ,HPLC - Abstract
The contamination of corn with fumonisin produced by Fusarium species represents an important risk for humans and animals. The incidence of Fusarium spp. and contamination by fumonisin B1 (FB1) were studied in field samples from 70 fields of corn during the 2005 and 2006 preharvest seasons in the province of Samsun, Turkey. Fusarium was the predominant genus isolated from the field samples, with F. verticillioides, F. proliferatum and F. subglutinans being the most commonly isolated species. The occurrence of Fusarium spp. varied each year, from 97.14% to 78.57% in 2005 and 2006, respectively. The widespread occurrence of FB1 was also observed across the Samsun province. All corn samples infected with F. verticillioides, F. proliferatum and F. subglutinans tested positive for FB1, but none were infected with FB2. Levels of FB1 ranged from 0.28 to 8.48 mg kg-1 in 2005 and from 0.11 to 2.77 mg kg-1 in 2006. The concentration of FB1 was lower than 2 mg kg-1 in 63.6% of the samples, 28.8% contained from 2 mg kg-1 to 5 mg kg-1, while 7.6% contained more than 5 mg kg-1. Our study shows that corn contamination with both Fusarium and FB1 was present throughout the Samsun province, but it was strongly dependent on environmental and seasonal conditions. However, there was no Fusarium contamination in certain native white-type and popcorn-type cultivars in 2005 and 2006., La contamination du maïs par la fumonisine produite par des espèces de Fusarium présente un risque important pour les humains et les animaux. L’incidence des espèces de Fusarium et la contamination par la fumonisine B1 (FB1) ont été étudiées durant la saison précédant la récolte en 2005 et 2006 dans des échantillons provenant de 70 champs de maïs de la province de Samsun, en Turquie. Fusarium était le genre prédominant dans les échantillons de champ, F. verticillioides, F. proliferatum et F. subglutinans étant les espèces les plus communément isolées. La présence d’espèces de Fusarium variait d’une année à l’autre, passant de 97,14 % à 78,57 % en 2005 et 2006, respectivement. La présence très répandue de FB1 a également été observée dans la province de Samsun. Tous les échantillons de maïs infectés par F. verticillioides, F. proliferatum et F. subglutinans étaient contaminés par la FB1, mais aucun n’était contaminé par la FB2. Le niveau d’infection par la FB1 variait entre 0,28 et 8,48 mg kg-1 en 2005 et entre 0,11 et 2,77 mg kg-1 en 2006. La concentration de FB1 était inférieure à 2 mg kg-1 dans 63,6 % des échantillons, 28,8 % en contenait de 2 mg kg-1 à 5 mg kg-1, alors que 7,6 % en contenait plus de 5 mg kg-1. Notre étude montre que la contamination du maïs par le Fusarium et la FB1 est répandue à travers la province de Samsun, mais qu’elle dépend fortement des conditions environnementales et saisonnières. Toutefois, certains cultivars indigènes de types blanc et popcorn n’étaient pas contaminés par le Fusarium en 2005 et 2006.
- Published
- 2009
- Full Text
- View/download PDF
48. Réactivité de silices fonctionnalisées par des groupements dithiocarbamates vis-à-vis de Co(II) et Ni(II) : vers une nouvelle méthode de diagnostic de l'exposition aux métaux lourds lors du recueil des urines
- Author
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Tzanis, Lydie, Laboratoire de Chimie Physique et Microbiologie pour l'Environnement (LCPME), Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC), Université Henri Poincaré - Nancy 1, and Alain Walcarius
- Subjects
PAN ,Complexation ,Matériaux hybrides ,CLHP ,commutation de colonne ,[CHIM.OTHE]Chemical Sciences/Other ,cobalt et nickel ,siloxydithiocarbamates ,Gel de silice - Abstract
The main object of the thesis concerns the development of a trapping method for quantitative analysis of carcinogenic - or likely to be - metal ions in urine, allowing to avoid sample transport in a liquid form. Among the metal ions a trace levels, we have been particularly interested in cobalt and nickel species. The approach presented here is based on solid/liquid extraction of metal ions by complexation on mesoporous organic-inorganic hybrid materials with large specific surface areas. The selected adsorbents are silica gels functionalised with dithiocarbamate groups. After their preparation by post-synthesis grafting using new siloxydithiocarbamate precursors, the functionalized silica gels have been characterized by various physico-chemical techniques and their behaviour in solution has been investigated. It shows that interactions between dithiocarbamate moieties and the silica surface can lead to a loss of grafted groups in the external solution, especially for extended periods in aqueous medium. However, these hybrids have been successfully used for quantitative sequestration of CoII and NiII from dilute solutions (1 to 500 µg L-1), within the pH range likely to be encountered in urinary environment. This study has also involved the development of an analytical method for the simultaneous and quantitative determination of these elements in solution. This was based on high performance liquid chromatography for which the best results were obtained using the switching column technique. Adsorption operations have proven to be very fast, which has allowed operating effectively in the implementation of cartridges through which the samples have been percolated. Efforts have also been made to define the optimal conditions for desorption, which was then applied to the quantitative analysis of analytes previously accumulated in the cartridge.; L'objectif principal de la thèse concerne la mise au point d'une méthode de piégeage et d'analyse quantitative de métaux cancérogènes ou susceptibles de l'être dans les urines, en permettant de s'affranchir du transport de l'échantillon sous forme liquide. Parmi les éléments traces métalliques (ETM), nous nous sommes intéressés plus particulièrement aux espèces du cobalt et du nickel. L'approche présentée repose sur l'extraction solide/liquide des ions métalliques par complexation sur des matériaux mésoporeux hybrides organo-minéraux à grande surface spécifique. Les matériaux adsorbant sélectionnés sont des silices fonctionnalisées par des groupements dithiocarbamate. Après avoir préparé ces supports par greffage au moyen de nouveaux précurseurs siloxydithiocarbamate, les matériaux fonctionnels ont été caractérisés par diverses techniques physico-chimiques et leur comportement en solution a été étudié. Il en ressort que les interactions entre ces fonctions dithiocarbamate et la surface de la silice peuvent conduire à une perte des greffons en milieu aqueux surtout pour des séjours prolongés en solution. Néanmoins, ces solides ont pu être exploités avec succès pour l'immobilisation quantitative des espèces CoII et NiII à partir de solutions diluées (de 1 à 500 µg.L-1), et ce dans la gamme de pH susceptible d'être rencontrée en milieu urinaire. Cette étude a nécessité la mise au point d'une méthode analytique de routine pour la détermination simultanée et quantitative de ces éléments en solution. Il s'agit de la chromatographie haute performance pour laquelle les meilleurs résultats ont été obtenus au moyen la technique dite de commutation de colonne. Les opérations d'adsorption se sont révélées être rapides, ce qui a permis d'opérer efficacement lors de la mise en oeuvre de cartouches au travers desquelles les échantillons ont été percolés. Des efforts ont également été consentis de manière à définir les conditions optimales de désorption en vue de l'analyse quantitative des analytes précédemment accumulés.
- Published
- 2008
49. Reactivity of silica gels functionalized by dithiocarbamates groups towards Co (II) and Ni (II) : a new method for diagnosis of exposure to heavy metals in the urine collection
- Author
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Tzanis, Lydie, Laboratoire de Chimie Physique et Microbiologie pour l'Environnement (LCPME), Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC), Université Henri Poincaré - Nancy 1, Alain Walcarius, and UL, Thèses
- Subjects
PAN ,[CHIM.OTHE] Chemical Sciences/Other ,Complexation ,Matériaux hybrides ,CLHP ,commutation de colonne ,[CHIM.OTHE]Chemical Sciences/Other ,cobalt et nickel ,siloxydithiocarbamates ,Gel de silice - Abstract
The main object of the thesis concerns the development of a trapping method for quantitative analysis of carcinogenic - or likely to be - metal ions in urine, allowing to avoid sample transport in a liquid form. Among the metal ions a trace levels, we have been particularly interested in cobalt and nickel species. The approach presented here is based on solid/liquid extraction of metal ions by complexation on mesoporous organic-inorganic hybrid materials with large specific surface areas. The selected adsorbents are silica gels functionalised with dithiocarbamate groups. After their preparation by post-synthesis grafting using new siloxydithiocarbamate precursors, the functionalized silica gels have been characterized by various physico-chemical techniques and their behaviour in solution has been investigated. It shows that interactions between dithiocarbamate moieties and the silica surface can lead to a loss of grafted groups in the external solution, especially for extended periods in aqueous medium. However, these hybrids have been successfully used for quantitative sequestration of CoII and NiII from dilute solutions (1 to 500 µg L-1), within the pH range likely to be encountered in urinary environment. This study has also involved the development of an analytical method for the simultaneous and quantitative determination of these elements in solution. This was based on high performance liquid chromatography for which the best results were obtained using the switching column technique. Adsorption operations have proven to be very fast, which has allowed operating effectively in the implementation of cartridges through which the samples have been percolated. Efforts have also been made to define the optimal conditions for desorption, which was then applied to the quantitative analysis of analytes previously accumulated in the cartridge., L'objectif principal de la thèse concerne la mise au point d'une méthode de piégeage et d'analyse quantitative de métaux cancérogènes ou susceptibles de l'être dans les urines, en permettant de s'affranchir du transport de l'échantillon sous forme liquide. Parmi les éléments traces métalliques (ETM), nous nous sommes intéressés plus particulièrement aux espèces du cobalt et du nickel. L'approche présentée repose sur l'extraction solide/liquide des ions métalliques par complexation sur des matériaux mésoporeux hybrides organo-minéraux à grande surface spécifique. Les matériaux adsorbant sélectionnés sont des silices fonctionnalisées par des groupements dithiocarbamate. Après avoir préparé ces supports par greffage au moyen de nouveaux précurseurs siloxydithiocarbamate, les matériaux fonctionnels ont été caractérisés par diverses techniques physico-chimiques et leur comportement en solution a été étudié. Il en ressort que les interactions entre ces fonctions dithiocarbamate et la surface de la silice peuvent conduire à une perte des greffons en milieu aqueux surtout pour des séjours prolongés en solution. Néanmoins, ces solides ont pu être exploités avec succès pour l'immobilisation quantitative des espèces CoII et NiII à partir de solutions diluées (de 1 à 500 µg.L-1), et ce dans la gamme de pH susceptible d'être rencontrée en milieu urinaire. Cette étude a nécessité la mise au point d'une méthode analytique de routine pour la détermination simultanée et quantitative de ces éléments en solution. Il s'agit de la chromatographie haute performance pour laquelle les meilleurs résultats ont été obtenus au moyen la technique dite de commutation de colonne. Les opérations d'adsorption se sont révélées être rapides, ce qui a permis d'opérer efficacement lors de la mise en oeuvre de cartouches au travers desquelles les échantillons ont été percolés. Des efforts ont également été consentis de manière à définir les conditions optimales de désorption en vue de l'analyse quantitative des analytes précédemment accumulés.
- Published
- 2008
50. Enantioselective DNA and RNA aptamers : chiral separation applications in micro-chromatography and capillary electrophoresis (CE)
- Author
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Ruta, Joséphine, Département de pharmacochimie moléculaire (DPM), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF), Université Joseph-Fourier - Grenoble I, Eric PEYRIN(Eric.Peyrin@ujf-grenoble.fr), and Ruta, Joséphine
- Subjects
[SDV.SP.MED] Life Sciences [q-bio]/Pharmaceutical sciences/Medication ,Sélecteurs chiraux ,EC ,SELEX ,Essai énantiosélectif ,Phase Stationnaire Chirale ,CLHP ,Aptamers ,CE ,[SDV.SP.MED]Life Sciences [q-bio]/Pharmaceutical sciences/Medication ,Stratégie d'immobilisation ,chiral stationnary phase ,Résolution chirale ,Immobilization strategy ,enantioselective assay ,HPLC ,Aptamères ,Chiral resolution ,Chiral selectors - Abstract
The separation of enantiomers is of a great interest in the pharmaceutical, chemical and food fields. Aptamers have been used by the Department of Molecular Pharmacochemistry (DPM) as new target-specific chiral selectors. These oligonucleotides, RNA or DNA, selected by SELEX (Systematic Evolution of Ligands by Exponential Enrichment), have the ability to bind their target molecules with an affinity equal (or superior) to that retrieved with the antibodies. The aim of this work is to study the enantioselective properties of RNA and DNA aptamers by micro-HPLC and CE. A chiral stationary phase L-RNA aptamer anti-D-histidine was designed using an immobilization strategy based on the biotin-streptavidin link. A novel covalent strategy for the immobilization of the aptamers was developed to enlarge the conditions of use and to improve the stability of these aptamers columns. The use of these new chiral selectors was then spread in an analysis by CE. The first study was accomplished using an L-RNA aptamer anti-D-arginine characterized by a very weak constant of dissociation (Kd = 330 nM) and a very high enantioselectivity (α = 12000). This study allowed to appreciate the special characteristics of this aptamer and to extend its use in an enantioselective competitive assay. An enantiomeric impurity as low as 0,01% was achieved. A similar assay, where a direct contact between the aptamer and its enantiomer target is favoured, allowed to increase the method sensitivity and could allow to reduce the detection limit thanks to the use of a fluorescence detection., La séparation d'énantiomères est d'un grand intérêt pour les industries pharmaceutiques, chimiques et agroalimentaires. Les aptamères sont utilisés au sein du Département de Pharmacochimie Moléculaire (DPM) en tant que nouveaux sélecteurs chiraux spécifiques d'une cible prédéterminée. Il s'agit d'oligonucléotides, en série ADN et ARN, générés par la procédure SELEX (Systematic Evolution of Ligands by Exponential Enrichment), ayant la capacité à fixer leurs molécules cibles avec une affinité égale voir supérieure à celle des anticorps. Ce travail a pour objectif d'étudier les propriétés énantiosélectives des aptamères, en série ADN et ARN, par micro-CLHP et EC. Une phase stationnaire chirale aptamère L-ARN anti-D-histidine a été créée en utilisant une stratégie d'immobilisation biotine-streptavidine dans le but d'étudier les propriétés énantiosélectives de cet oligonucléotide récemment isolé. Une nouvelle stratégie d'immobilisation covalente de l'aptamère a été développée afin d'élargir les conditions d'utilisation et d'améliorer la stabilité de ces colonnes aptamères. L'utilisation de ces nouveaux sélecteurs chiraux a ensuite été étendue à une analyse par EC. La première étude a été réalisée sur un aptamère test L-ARN anti-D-arginine caractérisé par de très fortes affinité (Kd = 330 nM) et énantiosélectivité (α = 12000). Ce travail a permis d'apprécier les caractéristiques exceptionnelles de cet aptamère et d'envisager son utilisation dans un essai énantiosélectif par compétition. Une impureté énantiomérique de 0,01% a ainsi été détectée. Un essai similaire, où un contact direct entre l'aptamère et son énantiomère cible est favorisé, a permis d'augmenter la sensibilité de la méthode et pourrait permettre d'abaisser la limite de détection grâce à l'utilisation d'une détection par fluorescence.
- Published
- 2008
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