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101.
Lucie Stuchlíková Robert Jirásko Ivan Vokřál Jiří Lamka Marcel Špulák Michal Holčapek Barbora Szotáková Hana Bártíková Milan Pour Lenka Skálová 《Analytical and bioanalytical chemistry》2013,405(5):1705-1712
Monepantel (MOP) belongs to a new class of anthelmintic drugs known as aminoacetonitrile derivatives. It was approved for use in veterinary practice in Czech Republic in 2011. So far, biotransformation and transport of MOP in target animals have been studied insufficiently, although the study of metabolic pathways of anthelmintics is very important for the efficacy of safety of therapy and evaluation of the risk of drug–drug interactions. The aim of this study was to identify MOP metabolites and to suggest the metabolic pathways of MOP in sheep. For this purpose, primary culture of ovine hepatocytes was used as a model in vitro system. After incubation, medium samples and homogenates of hepatocytes were extracted separately using solid-phase extraction. Analysis was performed using a hybrid quadrupole-time-of-flight analyzer with respect to high mass accuracy measurements in full scan and tandem mass spectra for the confirmation of an elemental composition. The obtained results revealed S-oxidation to sulfoxide and sulfone and arene hydroxylation as MOP phase I biotransformations. From phase II metabolites, MOP glucuronides, sulfates, and acetylcysteine conjugates were found. Based on the obtained results, a scheme of the metabolic pathway of MOP in sheep has been proposed. 相似文献
102.
Lenka Slavětínská Jiří Mosinger Martin Dračínský Martin Pošta 《Journal of inclusion phenomena and macrocyclic chemistry》2008,61(3-4):241-250
Disulfonated derivatives of 9,10-diphenyl anthracene (dsDPA) are known carriers of singlet oxygen. DsDPA and corresponding endoperoxides (dsDPAO2) form host–guest complexes with native cyclodextrins (i.e. β-CD and γ-CD). The modes of host–guest interaction were studied by 1H NMR and 2D-NMR (ROESY). Specific inclusions of phenyl groups of dsDPA/dsDPAO2 into the cyclodextrin cavities were found for both β-CD and γ-CD. The mode of interaction depends on the size of the CD cavity and the position of the sulfonate group. 相似文献
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105.
Tydlitát Vratislav Trník Anton Scheinherrová Lenka Podoba Rudolf Černý Robert 《Journal of Thermal Analysis and Calorimetry》2015,121(1):115-125
Journal of Thermal Analysis and Calorimetry - The calcined gypsum–lime–metakaolin–water system and its subsystems consisting of two and three components are analyzed using the... 相似文献
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107.
Anna Bonfiglio Lenka Pallova Dr. Vincent César Dr. Christophe Gourlaouen Dr. Stéphane Bellemin-Laponnaz Dr. Chantal Daniel Dr. Federico Polo Dr. Matteo Mauro 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(51):11751-11766
A novel class of phosphorescent cationic heterobimetallic IrIII/MI complexes, where MI=CuI ( 4 ) and AuI ( 5 ), is reported. The two metal centers are connected by the hybrid bridging 1,3-dimesityl-5-acetylimidazol-2-ylidene-4-olate (IMesAcac) ligand that combines both a chelating acetylacetonato-like and a monodentate N-heterocyclic carbene site coordinated onto an IrIII and a MI center, respectively. Complexes 4 and 5 have been prepared straightforwardly by a stepwise site-selective metalation with the zwitterionic [(IPr)MI(IMesAcac)] metalloproligand (IPr=1,3-(2,6-diisopropylphenyl)-2H-imidazol-2-ylidene) and they have been fully characterized by spectroscopic, electrochemical, and computational investigation. Complexes 4 and 5 display intense red emission arising from a low-energy excited state that is located onto the “Ir(C^N)” moiety featuring an admixed triplet ligand-centered/metal-to-ligand charge transfer (3IL/1MLCT) character. Comparison with the benchmark mononuclear complexes reveals negligible electronic coupling between the two distal metal centers at the electronic ground state. The bimetallic systems display enhanced photophysical properties in comparison with the parental congeners. Noteworthy, similar non-radiative rate constants have been determined along with a two-fold increase of radiative rate, yielding brightly red-emitting cyclometalating IrIII complexes. This finding is ascribed to the increased MLCT character of the emitting state in complexes 4 and 5 due to the smaller energy gap between the 3IL and 1MLCT manifolds, which mix via spin–orbit coupling. 相似文献
108.
Dr. Lenka Lorencova Dr. Tomas Bertok Dr. Aniko Bertokova Veronika Gajdosova Stefania Hroncekova Dr. Alica Vikartovska Dr. Peter Kasak Dr. Jan Tkac 《ChemElectroChem》2020,7(9):1955-1955
Invited for this month's cover picture is the group of Dr. Jan Tkac (head of the Department of Glycobiotechnology at the Institute of Chemistry at the Slovak Academy of Sciences, Slovakia). The cover picture shows a common eukaryotic cell with basic organelles, as well as intracellular formation/preparation of exosomes for express delivery to distant tissues. Read the full text of the Review at 10.1002/celc.202000075 . 相似文献
109.
An online method involving transient electrokinetic dosing and ITP with neutralization reaction boundary (NRB) and/or carrier ampholyte-free isoelectric focusing (CAF IEF) was developed for the preconcentration, preseparation, and analytical determination of glyphosate in aqueous samples containing low concentrations of the analyte of interest. Various parameters were investigated in the framework of an optimization study with the aim of achieving the maximum concentration limit of detection (cLOD) decrease in minimum time. The proposed method used CAF IEF and/or ITP with NRB. The sample was dosed to the column on the stationary reaction boundary (CAF IEF) and/or moving reaction boundary (ITP with NRB), whereat a sharp pH step exists. Here, charge reversal was due to the ampholytes, and/or acid accumulation occurred because of charge loss. Similarly, the accumulated sample was mobilized with TE and analyzed using classical ITP in the second analytical column. Glyphosate (GLY), the analyte of interest, was chosen as a model substance for ITP with NRB and preconcentration as well as focusing preconcentration and CAF IEF using the asymmetric purpose-built NRB. On one side of the asymmetric boundary was the zone of acidic pH; while the opposite side comprised a neutral/basic non-conductive zone of the ampholyte—in this case, GLY. Such an arrangement enables the use of a lower pH on the acidic side, which allows the focusing of strongly acidic ampholytes and the accumulation of weak acids. The electrolyte composition and the dosing time were optimized, and a 14-fold accumulation was achieved in 25 min compared to that by classical ITP and a 180-fold accumulation was achieved through CAF IEF and preconcentration with a glyphosate sample. Both methods are simple and can be conducted using all commercial ITP systems. 相似文献
110.
Dr. Vojtech Novohradsky Dr. Lenka Markova Dr. Hana Kostrhunova Prof. Dr. Jana Kasparkova Prof. José Ruiz Prof. Vicente Marchán Prof. Dr. Viktor Brabec 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(33):8547-8556
A cyclometalated IrIII complex conjugated to a far-red-emitting coumarin, IrIII-COUPY ( 3 ), was recently shown as a very promising photosensitizer suitable for photodynamic therapy of cancer. Therefore, the primary goal of this work was to deepen knowledge on the mechanism of its photoactivated antitumor action so that this information could be used to propose a new class of compounds as drug candidates for curing very hardly treatable human tumors, such as androgen resistant prostatic tumors of metastatic origin. Conventional anticancer chemotherapies exhibit several disadvantages, such as limited efficiency to target cancer stem cells (CSCs), which are considered the main reason for chemotherapy resistance, relapse, and metastasis. Herein, we show, using DU145 tumor cells, taken as the model of hormone-refractory and aggressive prostate cancer cells resistant to conventional antineoplastic drugs, that the photoactivated conjugate 3 very efficiently eliminates both prostate bulk (differentiated) and prostate hardly treatable CSCs simultaneously and with a similar efficiency. Notably, the very low toxicity of IrIII-COUPY conjugate in the prostate DU145 cells in the dark and its pronounced selectivity for tumor cells compared with noncancerous cells could result in low side effects and reduced damage of healthy cells during the photoactivated therapy by this agent. Moreover, the experiments performed with the 3D spheroids formed from DU145 CSCs showed that conjugate 3 can penetrate the inner layers of tumor spheres, which might markedly increase its therapeutic effect. Also interestingly, this conjugate induces apoptotic cell death in prostate cancer DU145 cells associated with calcium signaling flux in these cells and autophagy. To the best of our knowledge, this is the first study demonstrating that a photoactivatable metal-based compound is an efficient agent capable of killing even hardly treatable CSCs. 相似文献