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Coumarin Derivatives (coumarin + derivative)
Selected AbstractsEnantioselective Synthesis of (S)- and (R)-Tolterodine (I) by Asymmetric Hydrogenation of a Coumarin Derivative Obtained by a Heck Reaction.CHEMINFORM, Issue 50 2007Fausta Ulgheri Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF. [source] ChemInform Abstract: Synthesis, Characterization and anti-HIV and Antitumor Activities of New Coumarin Derivatives.CHEMINFORM, Issue 14 2008Yaseen A. Al-Soud Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source] Efficient Green Procedure for the Synthesis of Coumarin Derivatives by a One-Pot, Three-Component Reaction under Solvent-Free Conditions.CHEMINFORM, Issue 25 2007Liangce Rong Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF. [source] Synthesis and anti-Angiogenesis Activity of Coumarin Derivatives.CHEMINFORM, Issue 51 2006Seokjoon Lee Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF. [source] Synthesis of Methyl (E)-2-Nitromethylcinnamates Derived from Baylis,Hillman Acetates and Conversion into Several Coumarin Derivatives.CHEMINFORM, Issue 21 2005Wan Pyo Hong No abstract is available for this article. [source] Novel Coumarin Derivatives of Heterocyclic Compounds as Lipid-Lowering Agents.CHEMINFORM, Issue 43 2003Gurram R. Madhavan Abstract For Abstract see ChemInform Abstract in Full Text. [source] Highly Enantioselective Michael Addition of Cyclic 1,3-Dicarbonyl Compounds to ,,,-Unsaturated ,-Keto EstersADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 10 2010Xing-Kuan Chen Abstract A highly enantioselective Michael addition of cyclic 1,3-dicarbonyl compounds to ,,,-unsaturated ,-keto esters catalyzed by amino acid-derived thiourea-tertiary-amine catalysts is presented. Using 5,mol% of a novel tyrosine-derived thiourea catalyst, a series of chiral coumarin derivatives were obtained in excellent yields (up to 99%) and with up to 96% ee under very mild conditions within a short reaction time. [source] Facile, efficient, and eco-friendly synthesis of benzo[b]pyran-2-imines over MgO and transformation to the coumarin derivativesJOURNAL OF HETEROCYCLIC CHEMISTRY, Issue 6 2009Hassan Valizadeh Room temperature synthesis of benzo[b]pyran-2-imine derivatives via the Knoevenagel condensation of malononitrile and cyanoacetates with salicylaldehyde derivatives over MgO and their transformation to the known coumarins is described. The satisfactory results were obtained with good yields, short reaction time, and simplicity in the experimental procedure. J. Heterocyclic Chem., (2009). [source] Synthesis of potentially photoactivatable coumarin derivatives via a 1,3-dipolar cycloadditionJOURNAL OF HETEROCYCLIC CHEMISTRY, Issue 5 2008Elodie-Denise Chenot A copper (1)-catalyzed 1,3-dipolar cycloaddition reaction was used to prepare a series of mono and disubstituted 1,2,3-triazolyl-coumarins using a 1,3-cycloaddition ("Click Chemistry"). Starting coumarins were synthesized using classical or modified Pechmann's reaction. The propargyl group was introduced as either propargylether or as a propargylamide. Azides were prepared in a three steps procedure. Cycloaddition products, containing a coumarin and a photoactivatable moiety, were obtained in good yields. [source] Analysis of the interaction of substituted coumarins with the DPPH free radical by means of multivariate statisticsJOURNAL OF PHARMACY AND PHARMACOLOGY: AN INTERNATI ONAL JOURNAL OF PHARMACEUTICAL SCIENCE, Issue 9 2004Demetris Vrakas The interaction of some substituted coumarin derivatives with the stable 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical was analysed by means of multivariate statistics using a variety of molecular descriptors. The compounds contain a conjugated double bond system, which was considered to be an essential structural characteristic for the free-radical scavenging activity. Partial least-square analysis led to an adequate two-component model based on bulk descriptors and the electronic properties concerning atoms involved or next to the double-bond system. [source] Recent progress in the development of coumarin derivatives as potent anti-HIV agents,MEDICINAL RESEARCH REVIEWS, Issue 3 2003Donglei Yu Abstract Numerous plant-derived compounds have been evaluated for inhibitory effects against HIV replication, and some coumarins have been found to inhibit different stages in the HIV replication cycle. This review article describes recent progress in the discovery, structure modification, and structure,activity relationship studies of potent anti-HIV coumarin derivatives. A dicamphanoyl-khellactone (DCK) analog, which was discovered and developed in our laboratory, and calanolide A are currently in preclinical studies and clinical trials, respectively. © 2003 Wiley Periodicals, Inc. Med Res Rev, 23, No. 3, 322-345, 2003 [source] In-vitro antimicrobial, thermal and spectral studies of mixed ligand Cu(II) heterochelates of clioquinol and coumarin derivativesAPPLIED ORGANOMETALLIC CHEMISTRY, Issue 4 2010G. J. Kharadi Abstract The mixed-ligand heterochelates of Cu(II) with 5-chloro-7-iodo-8-hydroxyquinoline (clioquinol) and various uninegative bidentate ligands were prepared. The structure of mixed-ligand heterochelates was investigated using spectral, physicochemical, elemental analysis and thermal studies. The FAB-mass spectrum of [Cu(A2)(CQ)(H2O)2].2H2O has been carried out. Magnetic moment and reflectance spectral studies reveal that an octahedral geometry has been assigned to all the prepared heterochelates. The kinetic parameters such as order of reaction (n), the energy of activation (Ea), the pre-exponential factor (A), the activation entropy (,S#), the activation enthalpy (,H#) and the free energy of activation (,G#) have been reported. The ligands, metal salts, heterochelates, control and standard drug were tested for their in-vitro antibacterial activity against Escherichia coli, Pseudomonas aeruginosa, Serratia marcescens and Bacillus substilis. The metal complexes exhibit good activity against bacterial strains compared with parental compounds, and moderate compared with the standard drug (clioquinol). Copyright © 2010 John Wiley & Sons, Ltd. [source] Synthesis and Pharmacological Investigations of Some 4-Hydroxycoumarin DerivativesARCHIV DER PHARMAZIE, Issue 2 2003Ilia Manolov Abstract The synthesis of ten coumarin derivatives of 4-hydroxycoumarin and various unsaturated ketones and aldehydes is described. The structures of the synthesized compounds were confirmed by IR, 1H-NMR, and mass-spectral data. Acute toxicity studies of the compounds were performed on mice by oral and intraperitoneal administration. A comparative pharmacological study of the in vivo anticoagulant effects of the derivatives with respect to warfarin, showed that the compounds have anticoagulant activity. Compounds 4-hydroxy-3-[1-phenyl-2-(4,-chlorobenzoyl)ethyl]-2H -1-benzopyran-2-one 2b, 4-hydroxy-3-[1-(4-fluorophenyl)-3-oxobutyl]-2H -1-benzopyran-2-one 3a, and 3, 3,- p -bromobenzylidene-bis-(4-hydroxy-2H -1-benzopyran-2-one) 4b showed slight acute toxicity and a greater anticoagulant effect than warfarin. [source] A Note on Variance Estimation of the Aalen,Johansen Estimator of the Cumulative Incidence Function in Competing Risks, with a View towards Left-Truncated DataBIOMETRICAL JOURNAL, Issue 1 2010Arthur Allignol Abstract The Aalen,Johansen estimator is the standard nonparametric estimator of the cumulative incidence function in competing risks. Estimating its variance in small samples has attracted some interest recently, together with a critique of the usual martingale-based estimators. We show that the preferred estimator equals a Greenwood-type estimator that has been derived as a recursion formula using counting processes and martingales in a more general multistate framework. We also extend previous simulation studies on estimating the variance of the Aalen,Johansen estimator in small samples to left-truncated observation schemes, which may conveniently be handled within the counting processes framework. This investigation is motivated by a real data example on spontaneous abortion in pregnancies exposed to coumarin derivatives, where both competing risks and left-truncation have recently been shown to be crucial methodological issues (Meister and Schaefer (2008), Reproductive Toxicology26, 31,35). Multistate-type software and data are available online to perform the analyses. The Greenwood-type estimator is recommended for use in practice. [source] Lipophilicity Plays a Major Role in Modulating the Inhibition of Monoamine Oxidase B by 7-Substituted CoumarinsCHEMISTRY & BIODIVERSITY, Issue 2 2006Angelo Carotti Abstract A series of coumarin derivatives (1,22), bearing at the 7-position ether, ketone, ester, carbamate, or amide functions of varying size and lipophilicity, were synthesized and investigated for their in vitro monoamine oxidase-A and -B (MAO-A and -B) inhibitory activities. Most of the compounds acted preferentially as MAO-B inhibitors, with IC50 values in the micromolar to low-nanomolar range. A structure,activity-relationship (SAR) study highlighted lipophilicity as an important property modulating the MAO-B inhibition potency of 7-substituted coumarins, as shown by a linear correlation (n=20, r2=0.72) between pIC50 and calculated log P values. The stability of ester-containing coumarin derivatives in rat plasma provided information on factors that either favor (lipophilicity) or decrease (steric hindrance) esterase-catalyzed hydrolysis. Two compounds (14 and 22) were selected to investigate how lipophilicity and enzymatic stability may affect in vivo MAO activities, as assayed ex vivo in rat. The most-potent and -selective MAO-B inhibitor 22 (=7-[(3,4-difluorobenzyl)oxy]-3,4-dimethyl-1-benzopyran-2(2H)-one) within the examined series significantly inhibited (>60%) ex vivo rat-liver and striatal MAO-B activities 1,h after intraperitoneal administration of high doses (100 and 300,,mol kg,1), revealing its ability to cross the blood,brain barrier. At the same doses, liver and striatum MAO-A was less inhibited in vivo, somehow reflecting MAO-B selectivity, as assessed in vitro. In contrast, the metabolically less stable derivative 14, bearing an isopropyl ester in the lateral chain, had a weak effect on hepatic MAO-B activity in vivo, and none on striatal MAO-B, but, surprisingly, displayed inhibitory effects on MAO-A in both peripheral and brain tissues. [source] Synthesis of some new fused coumarin derivativesCHINESE JOURNAL OF CHEMISTRY, Issue 4 2000El-Deen Ibrahim Mohey Abstract 2-Hydrazino-4-hydroxy-5H -[1]-benzopyrano-[4,3-d]-pyrimidin-5-one (3) was prepared via condensation of 2 with hydrazine hydrate. Treatment of 3 with methylene chloride, ethyl chloroformate, ethyl chloroacetate and benzaldehyde yielded the corresponding 2 - ( substituted ) hydrazino - 4 -hydro-xy-5H -[1]-benzopyrano-[4,3-d]-pyrimidin-5-one (4, 5, 6, and 10), followed by cyclization of 4, 5 and 6 with dimethyl formamide and fused sodium acetate under reflux, while compound 10 was cyclized with bromine and sodium acetate in acetic acid. Compound 3 reacted with ,-(toloyl) acrylic acid, ethyl ,-cyano- p -methoxycinnamate, diethyl malonate and acetyl chloride affording the corresponding 2-(substituted) hydrazino-4-hydroxy-5H -[1]-benzopyrano-[4,3-d]-pyrimidin-5-one (12, 13, 14, 15 and 16). [source] | ||||||||||||||||||||||