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Chitosan-mediated synthesis of carbon nanotube-gold nanohybrids

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Science China Chemistry 2010年第9期53卷 2015-2018页

作者： GRAVEL Edmond FOILLARD Stéphanie DORIS Eric CEA iBiTecSService de Chimie Bioorganique et de Marquage

Metal-nanotube nanohybrids were produced by in situ synthesis and stabilization of gold nanoparticles on chitosan-functionalized carbon *** formation of gold nanoparticles from tetrachloroauric acid was observed after only a few minutes of contact with the functionalized nanotubes,at room *** results suggest that adsorption of chitosan at the surface of carbon nanotubes permits smooth reduction of the metallic salt and efficient anchoring of gold nanoparticles to the nanotubes.

关键词： nanohybrid carbon nanotube gold nanoparticle

Chemical constituents, cytotoxic, antifungal and antimicrobial properties of Centaurea diluta Ait. subsp. algeriensis(Coss. & Dur.) Maire

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Asian Pacific Journal of Tropical Medicine 2016年第6期9卷 537-543页

作者： Hanene Zater Joelle Huet Veronique Fontaine Samir Benayache Caroline Stevigny Pierre Duez Fadila Benayache Unite de recherche : Valorisation des Ressources Naturelles Molecules Bioactives et Analyses Physicochimiques et Biologiques (VARENBIOMOL) Faculte des Sciences Exactes Universite Freres Mentouri Constantine 125000 ConstantineAlgerie Universite Ziane Achour Cite du 5 JuilletRoute Moudjbara BP:311717000 DjelfaAlgerie Laboratoire de pharmacognosie de Bromatologie et de Nutrition Humaine Universite Libre de Bruxelles (ULB)1050 BruxellesBelgique Laboratoire de Biopolymere et nanomateriaux supramoleculaire Universite Libre de Bruxelles (ULB)1050 BruxellesBelgique Unite de Microbiologie Pharmaceutique et Hygiene Faculte de Pharmacie Universite Libre de Bruxelles (ULB)1050 BrxellesBelgique service de chimie therapeutique et de pharmacognosie Universite de Mons (UMONS)7000MonsBelgique

Objective:To investigate the chemical composition of a moderately polar extract(CHC1_3 soluble part of the MeOH-H_2O extract) obtained from the aerial parts(leaves and flowers) of Centaurea diluta ***(Coss.& Dur.) Maire,a species endemic to Algeria and Morocco on which no reports are available to *** evaluate in vitro the cytotoxic,antifungal and antimicrobial activities of this extract and the cytotoxic and antimicrobial activities of its isolated secondary ***:the cytotoxic effects of the extract were investigated on 3 human cancer cell lines *** A549 non-small-cell lung carcinoma(NSCLC),the MCF7 breast adenocarcinoma and the U373 glioblastoma using a MTT colorimetric *** data allowed to guide the fractionation of the extract by separation and purification on silica gel 60(CC and TLC).the isolated compounds which were characterized by spectral analysis,mainly HR-ESIMS,HR-EIMS,UV and NMR experiments(~1H,^(13)C,COSY,ROESY,HSQC and HMBC) and comparison of their spectroscopic data with those reported in the literature,were evaluated for cytotoxic activities on six cancer cell lines(A549,MCF7,U373,Hs683 human glioma,PC3 human prostate and B16-F10 murine melanoma).the direct and indirect antibacterial and antifungal activities were determined using microdilution methods for the raw extract and TLC-bioautography and microdilution methods against standard and clinical strains for the isolated ***:the raw extract reduced cell viability with IC_(50)s of 27,25 and 21 μg/mL on A549,MCF7 and U373,*** secondary metabolites:two phenolic compounds(vanillin 1,paridol 3),a lignan[(-)-arctigenin 2]and two flavonoid aglycones(eupatilin 4 and jaceosidin 5),were then isolated from this *** cytotoxic effects were observed for(-)-arctigenin 2(IC_(50)s:28 and 33μM on Hs683 and B16-F10,respectively),eupatilin 4(IC_(50)s:33 and 47 μM on B16-F10 and PC3,respectively) and jaceosidin 5(IC_(50)s:32 a

关键词： Flavonoids Lignans Centaurea diluta Asteraceae Cytotoxic activity Direct and indirect antimicrobial activity MRSA

Quality Control of Paracetamol Generic Tablets Marketed in Benin and Search of Its Two Impurities P-Aminophenol and P-Nitrophenol by HPLC-UV/Visible

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American Journal of Analytical Chemistry 2022年第11期13卷 449-460页

作者： Yemoa Loconon Achille Agbokponto Janvier Engelbert Assanhou Assogba Gabin Adetona Pauline Doffon Parfait Ganfon Habib Roland Marini Djang’eing’a Laboratoire de chimie analytique et Analyse des Médicaments Unité de Formation et de Recherche en Pharmacie Faculté des Sciences de la Santé. Université d’Abomey Calavi Cotonou Bénin Laboratoire de Pharmacie Galénique et de Technologie Pharmaceutique Unité de Formation et de Recherche en Pharmacie Faculté des Sciences de la Santé Université d’Abomey Calavi Cotonou Bénin Laboratoire de pharmacognosie et de de Phytothérapie Unité de Formation et de Recherche en Pharmacie Faculté des Sciences de la Santé Université d’Abomey Calavi Cotonou Bénin Laboratoire de chimie Analytique Pharmaceutique Departement de Pharmacie Université de Liège (ULiège) Liège Belgium

In this work, we evaluated the quality of paracetamol generic tablets while seeking its two main impurities namely 4-para-aminophenol (4-AP) and 4-para-nitrophenol (4-NP) which have nephrotoxic and teratogenic properties. Ninety-four (94) samples were collected at various levels of the medicine supply chain and illegal markets in Benin for quality control tests such as visual inspection, pharmacotechnical tests as mass variation, disintegration test, dissolution test, followed by HPLC UV-Vis identification and assay of paracetamol, 4-AP and 4-NP. the analytes were separated on C18 Lichrocart column (250 mm × 4.0 mm i.d, 5 μm);the mobile phase was MeOH:10 mM ammonium acetate buffer pH 6.8 (35:65) pumped at a flow rate of 1 ml/min. the detection was done at 245 nm. Analysis of our results shows that 77.7% of the samples did not comply with the visual inspection test requirements, 2.1% did not pass the mass variation test, 24.3% of the sample batches didn’t comply with the disintegration test requirements. In addition none of these uncomply batches passed the dissolution test, even if the identification test indicated that all samples contained paracetamol. None contained 4-NP (acceptance limit thin acceptance limit (4-AP the paracetamol assay, 80.9% complied with the specifications of the pharmacopoeias taken as reference (90% - 110%;USP). Further, broader studies should be conducted according to the same rules of good practice for a more comprehensive analysis of the situation. Generally the quality control of paracetamol in most African countries, particularly in Benin, is based on pharmacotechnical tests and paracetamol assay. this work, in addition to the usual tests, showed the importance to search for paracetamol and other drugs’ impurities during their routine quality control.

关键词： Quality Control Substandard Medicines Paracetamol P-Aminophenol P-Nitrophenol Benin

Methodology of factorial design deriving guidelines for simulation of growth curve and production of sugars by Spirulina (Arthrospira) maxima

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Journal of Central South University of Technology 2001年第4期8卷 228-233页

作者： NIE Zhen yuan XIA Jin lan LEVERT J.M. Institute of Bioengineering Department of Mineral EngineeringCentral South UniversityChangsha 410083China service de chimie et Biochimie Appliquées FacultéPolytechnique de MonsMons 7000Belgique

It is practical, economic and sometimes essential to derive rules or conclusions by performing lesser runs of experiments. In this part, a methodology based on 2 f factorial design was brought up to derive guidelines to simulate growth curve and production of sugars by Spirulina (Arthrospira) maxima . the growth curve or accumulation process of sugars was idealized by sets of straight lines limited by phase transfers of growth or accumulation of sugars. Normal analyses of the critical values of the transfers were used to derive their linear relationships with the initial conditions of the experimental factors. these linear functions were called guidelines and were used to simulate the growth curve or accumulation of sugars. Generalization of the guideline technique was determined by the kinetic limitation of nutrient nitrogen or sulfur that was dependent upon their stoichiometric deficiency directly derived from their initial values in the medium. this method uses the initial conditions of culture and does not need measurements of concentrations of nitrate, sulfate and pigments during cultivation. It is a practical and useful alternative way to trace and predict approximately the growth curve and production of sugars by S. maxima .

关键词： factorial design guideline simulation growth production of sugar Arthrospira Spirulina maxima

Biosynthesis of ^(13)C-Labeled Amino Acids and Sugars by Spirulina (Arthrospira) Maxima in a Parallelepiped Photobioreactor

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Chinese Journal of Chemical Engineering 2002年第5期10卷 102-106页

作者：夏金兰聂珍媛 J.M.Levert Institute of Bioengineering Central South University Changsha 410083 service de chimie et Biochimie Appliquees Faculte Polytechnique de Mons Mons Belgique 7000

this paper presents the investigation on biosynthesis of high-value-added amino acids and sugars labeled uniformly with stable isotope 13C by microalga Spirulina (Arthrospira) maxima in a parallelepiped photobioreactor. the kinetic data of both batch and continuous cultures with characterization of the amino acids and sugars are shown. the continuous culture without nutrients deficiency is for biosynthesis of amino acids, with tyrosine as one of the principal constituents, and the batch culture with deficiency in nitrogen is for biosynthesis of labeled glucose that is up to 64% versus dry mass of cells.

关键词： amino acid microalga parallelepiped photobioreactor Spirulina (Arthrospira) maxima 13C-labeled sugar

Fractionation and characterization of polysaccharides from cyanobacterium Spirulina (Arthrospira) maxima in nitrogen-limited batch culture

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Journal of Central South University of Technology 2002年第2期9卷 81-86页

作者：聂珍媛夏金兰 J.M.LEVERT Institute of Bioengineering Faculty of Resource Processing and Bioengineering Central South University Changsha 410083 China service de chimie et Biochimie Appliquées Faculté Polytechnique de Mons Mons 7000 Belgque

By a sequentially selective extraction procedure, polysaccharides (PS) from cyanobacterium Spirulina (Arthrospira) maxima that can be bio functionally healthy components were fractionated in four parts including the culture medium (PSCM), the external layers of the cell (PSEL), the cell wall (PSCW) and storage granules (PSSG). the four fractionated parts of polysaccharides were characterized by gas liquid chromatography (GLC) equipped with FID and fused silica capillary column (15 m×0.53 mm i. d.). the contents of PSCM, PSEL, PSCW and PSSG were about 2.0%, 2.6%, 10.0% and 52.0% to cell dry matter, respectively. Glucose was almost the only monosaccharide in PSSG and PSCW and most predominant in PSEL, while in PSCM, xylose, rhamnose and glucose were the main ones. Two uronic acids represented by glucuronic acid and galacturoic acid, six neutral monosaccharides including fucose, rhamnose, xylose, mannose, galactose and glucose, and two possible unidentified sugars were found in PSEL and PSCM. these data are valuable for the selective productions of high added value sugars from Spirulina .

关键词：蓝藻菌多糖分馏螺旋藻属 PSSG PSCW PSEL

A new friedelane triterpenoid and saponin with moderate antimicrobial activity from the stems of Drypetes laciniata

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Chinese Chemical Letters 2011年第2期22卷 171-174页

作者： Simone Veronique Fannang Victor Kuete Celine Mbazoa Djama Marlise Diane J.Dongfack Jean Duplex Wansi Francois Tillequin Elisabeth Seguin Elizabeth Chosson Jean Wandji Laboratoire de Synthese et de Produits Naturels Departement de Chimie Organique de l'Universite de Yaounde-1Faculte des SciencesP.O.Box 812 YaoundeCameroon department of Biochemistry University of DschangFaculty of ScienceP.O.Box 67 DschangCameroon Laboratoire de pharmacognosie de l'Universite Paris descartes UMR/CNRS No.8638Faculte des Sciences Biologiques et Pharmaceutiques4-Avenue de l'Observatoire75006 ParisFrance department of Chemistry University of DoualaFaculty of ScienceP.O.Box 24157 DoualaCameroon Laboratoire de pharmacognosie UFR de Medecine Pharmacie Rouen22-Bld Gambetta76183 Rouen Cedex 1France

A new friedelane-type triterpene named 3β-hydroxyfriedelane-7,12,22-trione,as well as nine known compounds were isolated from the whole stems of Drypetes laciniata Hutch.（Euphorbiaceae）.their structures were established on the basis of spectroscopic *** new triterpene derivative and a known saponin were tested for antimicrobial and antifungal activities and they appeared to be moderate active.

关键词： Drypetes laciniata Euphorbiaceae Stem Friedelane-type triterpenoid Antimicrobial activity

New flavan and unusual chalcone glycosides from Drypetes parvifolia

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Chinese Chemical Letters 2008年第8期19卷 943-946页

作者： Viviane Nadège Nenkep Jovita Chi Shirri Hanh Trinh Van-Dufat Falindor Sipepnou Philippe Vérité Elisabeth Seguin Francois Tillequin Jean Wandji department of Organic Chemistry University of Yaounde-1Faculty of ScienceP.O.Box 812YaoundeCameroon Laboratoire de pharmacognosie de l'Université Paris descartes UMR/CNRS N 8638Faculté des Sciences Biologiques et Pharmaceutiques4-Avenue de l'Observatoire75006 ParisFrance Laboratoire de chimie Analytique UFR de Médecine Pharmacie Rouen22-Bid Gambetta76183 Rouen Cedex 1France Laboratoire de pharmacognosie UFR de Médecine Pharmacie Rouen22-Bld Gambetta76183 Rouen Cedex 1France

Two new compounds 7-hydroxy-5-O-（β-D-glucopyranoside） flavan （1） and （Z）-4＇,6＇-dihydroxy-2＇-O-（β-D-glucopyranoside） chalcone （2）, along with eight known compounds, were isolated from the stem bark of Drypetes parvifolia （Euphorbiaceae）. their structures were established on the basis of spectroscopic analysis and chemical evidence.

关键词： Drypetes parvifolia Flavonoid glycosides 7-Hydroxy-5-O-(β-D-glucopyranoside) flavan (Z)-4',6'-Dihydroxy-2'-O-(β-D-glucopyr-anoside) chalcone

Advanced protection against environmental degradation of silver mirror stacks for space application

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Journal of Materials Science & Technology 2021年第5期64卷 1-9页

作者： Rajendra Kurapati Vincent Maurice Antoine Seyeux Lorena H.Klein Dimitri Mercier Gregory Chauveau Catherine Grees-Besset Loic Berthod Philippe Marcus PSL Research University CNRS-Chimie ParisTechInstitut De Recherche De Chimie ParisPhysical Chemistry of Surfaces Group11 Rue Pierre Et Marie Curie75005 ParisFrance CILAS MARSEILLE 600 Avenue De La Roche FourcadePole ALPHA Sud-Saint Mitre13400 AubagneFrance CNES Sous-direction Assurance QualitéService TechnologiesMatériaux Et Procédés18 AvenueÉdouard Belin31401 ToulouseFrance

Protection of silver mirror stacks from environmental degradation before launching is crucial for space ***,we report a comparative study of the advanced protection of silver mirror stacks for space telescopes provided by SiO_(2)and Al_(2)O_(3)coatings in conditions of accelerated aging by *** model silver stack samples were deposited by cathodic magnetron sputtering on a reference silica substrate for optical applications and a surface-pretreated SiC *** aging was per-formed in dry and more severe wet *** micrographic observations,surface and interface analysis by Time-of Flight Secondary Ion Mass Spectrometry(ToF-SIMS)and reflectivity measurements were combined to comparatively study the effects of *** results show a lower kinetics of degradation by accelerated aging of the stacks protected by the alumina coating in comparable test conditions.

关键词： Mirror layers Protection Layers Silver Atmospheric corrosion Accelerated aging Surface analysis Space applications