- Rich spectroscopic and molecular dynamic studies on the interaction of cytotoxic Pt(II) and Pd(II) complexes of glycine derivatives with calf thymus DNA
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Some amino acid derivatives, such as R-glycine, have been synthesized together with their full spectroscopic characterization. The sodium salts of these bidentate amino acid ligands have been interacted with [M(bpy)(H2O)2](NO3)2 giving the corresponding some new complexes with formula [M(bpy)(R-gly)]NO3 (where M is Pt(II) or Pd(II), bpy is 2,2′-bipyridine and R-gly is butyl-, hexyl-and octyl-glycine). Due to less solubility of octyl derivatives, the biological activities of butyl and hexyl derivatives have been tested against chronic myelogenous leukemia cell line, K562. The interaction of these complexes with highly polymerized calf thymus DNA has been extensively studied by means of electronic absorption, fluorescence and other measurements. The experimental results suggest that these complexes positive cooperatively bind to DNA presumably via groove binding. Molecular dynamic results show that the DNA structure is largely maintained its native structure in hexylglycine derivative-water mixtures and at lower temperatures. The simulation data indicates that the more destabilizing effect of butylglycine is induced by preferential accumulation of these molecules around the DNA and due to their more negative free energy of binding via groove binding.
- Eslami Moghadam, Mahboube,Saidifar, Maryam,Divsalar, Adeleh,Mansouri-Torshizi, Hassan,Saboury, Ali Akbar,Farhangian, Hossein,Ghadamgahi, Maryam
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p. 203 - 219
(2016/01/20)
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- Iridium porphyrin catalyzed N-H insertion reactions: Scope and mechanism
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Ir(TTP)CH3 catalyzed N-H insertion reactions between ethyl diazoacetate (EDA) or methyl phenyldiazoacetate (MPDA) and a variety of aryl, aliphatic, primary, and secondary amines to generate substituted glycine esters with modest to high yields. Aniline substrates generally gave yields above 80%, with up to 105 catalyst turnovers, and without slow addition of the diazo reagent. Good yields were also achieved with aliphatic amines, though higher catalyst loadings and slow addition of the amine were necessary in some cases. Primary amines reacted with EDA to generate both single- and double-insertion products, either of which could be produced selectively in high yield with the proper choice of stoichiometric ratios and reaction temperature. Notably, mixed trisubstituted amines, RN(CH2CO2Et) (CHPhCO2Me), were generated from the insertion of 1 equiv of EDA and 1 equiv of MPDA into primary amines. The N-H insertion mechanism was examined using substrate competition studies, trapping experiments, and multiple spectroscopic techniques. Substrate competition studies using pairs of amines with EDA or MPDA revealed Hammett correlations with respective slopes of ρ = 0.15 and ρ+ = -0.56 as well as kinetic isotope ratios of k H/kD = 1.0 ± 0.2 and 2.7 ± 0.2. Competitive amine binding to the iridium center was demonstrated by kinetics and equilibrium binding studies. Equilibrium binding constants ranged from 102 to 105. Monitoring the reaction by absorption spectroscopy revealed a transient metalloporphyrin complex. The lifetime of this species was dependent on the nature of the amine substrate, which suggests that the catalytic cycle proceeds through a metal-ylide intermediate.
- Anding, Bernie J.,Woo, L. Keith
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p. 2599 - 2607
(2013/06/26)
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- Ruthenium Catalysts and Uses Thereof
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Ruthenium nanoparticles supported on non-cross-linked soluble polystyrene were prepared by reacting [RuCl2(C6H5CO2Et)]2 with polystyrene in open air. They effectively catalyze intra- and intermolecular carbenoid insertion into C—H and N—H bonds, alkene cyclopropanation, and ammonium ylide/[2,3]-sigmatropic rearrangement reactions. This supported ruthenium catalyst is much more reactive than [RuCl2(p-cymene)]2 and Ru(Por)CO] for catalytic intermolecular carbenoid C—H bond insertion into saturated alkanes. By using a-diazoacetamide as a substrate for intramolecular carbenoid C—H insertion, the supported ruthenium catalyst can be to recovered and reused for ten successive iterations without significant loss of activity.
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Page/Page column 4; 9
(2011/02/15)
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- Synthesis, characterization and biological activities of novel (E)-3-(1-(alkyloxyamino)ethylidene)-1-alkylpyrrolidine-2,4-dione derivatives
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Twenty novel tetramic acid derivatives (E)-3-(1-(alkyloxyamino)ethylidene)- 1-alkylpyrrolidine-2,4-diones were synthesized by the reaction of 3-(1-hydroxyethylidene)pyrrolidine-2,4-diones with O-alkyl hydroxylamines. The title compounds were confirmed by
- Zhu, Zhao-Yong,Shi, Qing-Ming,Han, Bao-Feng,Wang, Xian-Feng,Qiang, Sheng,Yang, Chun-Long
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experimental part
p. 2467 - 2472
(2010/12/18)
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- Hit-to-lead optimization of pyrrolo[1,2-a]quinoxalines as novel cannabinoid type 1 receptor antagonists
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Hit-to-lead optimization of a novel series of N-alkyl-N-[2-oxo-2-(4-aryl-4H-pyrrolo[1,2-a]quinoxaline-5-yl)-ethyl]-car boxylic acid amides, derived from a high throughput screening (HTS) hit, are described. Subsequent optimization led to identification of
- Szabo, Gyoergy,Kiss, Robert,Payer-Lengyel, Dora,Vukics, Krisztina,Szikra, Judit,Baki, Andrea,Molnar, Laszlo,Fischer, Janos,Keseru, Gyoergy M.
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scheme or table
p. 3471 - 3475
(2010/02/28)
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- 5-Benzylidene-hydantoins: Synthesis and antiproliferative activity on A549 lung cancer cell line
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Benzylidene hydantoins have been recently reported as a new class of EGFR inhibitors. We describe here a simple and efficient methodology for the parallel solution-phase synthesis of a library of 5-benzylidene hydantoins, which were evaluated for antiproliferative activity on the human lung adenocarcinoma A549 cell line. Various substituents at positions 1, 3 and 5 on the hydantoin nucleus were examined. In the presence of a 5-benzylidene group and of a lipophilic substituent at position 1, most of the tested compounds inhibited cell proliferation at a concentration of 20 μM. Compound 7 (UPR1024), bearing 1-phenethyl and (E)-5-p-OH-benzylidene substituents, was found to be the most active derivative of the series. It inhibited EGFR autophosphorylation and induced DNA damage in A549 cells. Compound 7 and other synthesized 5-benzylidene hydantoin derivatives increased p53 levels, suggesting that the dual mechanism of action was a common feature shared by compound 7 and other member of the series.
- Zuliani, Valentina,Carmi, Caterina,Rivara, Mirko,Fantini, Marco,Lodola, Alessio,Vacondio, Federica,Bordi, Fabrizio,Plazzi, Pier Vincenzo,Cavazzoni, Andrea,Galetti, Maricla,Alfieri, Roberta R.,Petronini, Pier Giorgio,Mor, Marco
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experimental part
p. 3471 - 3479
(2009/12/24)
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- Oxidative desulfurization of azole-2-thiones with benzoyl peroxide: Syntheses of ionic liquids and other azolium salts
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1-Alkyl-3-methylimidazole-2-thiones were prepared from amino esters in one pot and converted to inherently halide-free 1-alkyl-3-methylimidazolium benzoates by oxidation with benzoyl peroxide followed by a novel anion exchange. Also reported are the outcomes of exchanges with other anions, acidifications of the imidazolium benzoates to other salts, and extension of the method to the syntheses of 1,3-diphenylimidazolium and 3-methyl- and -butylthiazolium salts. Wiley-VCH Verlag GmbH & Co. KGaA, 2007.
- Wolfe, Derek M.,Schreiner, Peter R.
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p. 2825 - 2838
(2008/03/13)
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- Microwave-assisted synthesis of substituted hexahydropyrrolo[3,2-c] quinolines
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New compounds with the ethyl hexahydro-1H-pyrrolo[3,2-c]quinoline-2- carboxylate skeleton were prepared by microwave-assisted intramolecular 1,3-dipolar cycloaddition reactions. The reactions were carried out under solvent-free conditions and compared with the same reaction in the presence of a solvent and a catalyst. Steric effects on the selectivity of the reaction were noted and evaluated.
- Neuschl, Michal,Bogdal, Darek,Potacek, Milan
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- Microwave-assisted solvent-free intramolecular 1,3-dipolar cycloaddition reactions leading to hexahydrochromeno[4,3-b]pyrroles: scope and limitations
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We report the microwave-assisted solvent-free synthesis of hexahydrochromeno[4,3-b]pyrroles. Intramolecular 1,3-dipolar cycloadditions proceed under these conditions within 15-40 min in 16-84% yields. An influence of the microwave irradiation upon various [3+2] cycloaddition reaction intermediates was studied. Additionally, a scope and limitations of these reactions including an influence of the dipolarophile geometry upon the cycloaddition selectivity and steric demands of the dipole upon its reactivity were also disclosed. These observations led us to postulate a preferable transition state of the reaction. Finally, an influence of the microwave irradiation to the isomerization of activated olefins was also described.
- Pospí?il, Ji?í,Potá?ek, Milan
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p. 337 - 346
(2007/10/03)
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- DEFORMYLASE INHIBITOR, PROCESS FOR PREPARING THE SAME, AND ANTIBACTERIAL COMPOSITION COMPRISING THE SAME
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Provided are a novel compound useful for a deformylase inhibitor with excellent antibacterial activity or a pharmaceutically acceptable salt thereof, a process for preparing the same, and an antibacterial composition including the same as an active ingred
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- Synthesis and structure-activity relationships of potential anticonvulsants based on 2-piperidinecarboxylic acid and related pharmacophores
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Using N-(2,6-dimethyl)phenyl-2-piperidinecarboxamide (1) and N-(α-methylbenzyl)-2-piperidinecarboxamide (2) as structural leads, a variety of analogues were synthesised and evaluated for anticonvulsant activity in the MES test in mice. In the N-benzyl series, introduction of 3-Cl, 4-Cl, 3,4-Cl2, or 3-CF3 groups on the aromatic ring led to an increase in MES activity. Replacement of the α-methyl group by either i-Pr or benzyl groups enhanced MES activity with no increase in neurotoxicity. Substitution on the piperidine ring nitrogen led to a decrease in MES activity and neurotoxicity, while reduction of the amide carbonyl led to a complete loss of activity. Movement of the carboxamide group to either the 3- or 4-positions of the piperidine ring decreased MES activity and neurotoxicity. Incorporation of the piperidine ring into a tetrahydroisoquinoline or diazahydrinone nucleus led to increased neurotoxicity. In the N-(2,6-dimethyl)phenyl series, opening of the piperidine ring between the 1- and 6-positions gave the active norleucine derivative 75 (ED50 = 5.8 mg kg-1, TD50 = 36.4 mg kg-1, PI = 6.3). Replacement of the piperidine ring of 1 by cycloalkane (cyclohexane, cyclopentane, and cyclobutane) resulted in compounds with decreased MES activity and neurotoxicity, whereas replacement of the piperidine ring by a 4-pyridyl group led to a retention of MES activity with a comparable PI. Simplification of the 2-piperidinecarboxamide nucleus of 1 into a glycinecarboxamide nucleus led to about a six-fold decrease in MES activity. The 2,6-dimethylanilides were the most potent compounds in the MES test in each group of compounds evaluated, and compounds 50 and 75 should be useful leads in the development of agents for the treatment of tonic-clonic and partial seizures in man.
- Ho, Bin,Michael Crider,Stables, James P
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p. 265 - 286
(2007/10/03)
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- Kinetics and detemination of ethyl chloroacetate and ethyl bromoacetate with piperidine
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A simple sensitive potentiometric method has been developed for determination of active haloester. It is based on the reaction of haloester with excess piperidine in ethanol at 40°. Under the optimum conditions the average recovery is 97%. The reaction proceeds kinetically as a pseudo-first order reaction. The reactivity of tested amines towards haloester follows the order : benzylamine n-butylamine ethylamine piperidine. The activation parameters have been calculated and relevant reaction mechanism has been suggested.
- Iskander, Madlene L.,Badawy,Ahmed,Ayoub
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p. 333 - 336
(2007/10/03)
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- Peptide based interleukin-1β converting enzyme (ICE) inhibitors: Synthesis, structure activity relationships and crystallographic study of the ICE-inhibitor complex
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Based on the X-ray structure of the complex of Ac-Tyr-Val-Ala-Asp-H (L- 709049) and interleukin-1β converting enzyme (ICE), we synthesized compounds which were derived from 2-NapCO-Val-Pro-Asp-CH2OPh (1) to obtain a potent inhibitor in the cell
- Okamoto, Yoshinori,Anan, Hideki,Nakai, Eiichi,Morihira, Koichiro,Yonetoku, Yasuhiro,Kurihara, Hiroyuki,Sakashita, Hitoshi,Terai, Yoshiya,Takeuchi, Makoto,Shibanuma, Tadao,Isomura, Yasuo
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