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1.
Monika Kořenková Dr. Ing. Martin Hejda Prof. Milan Erben Dr. Ing. Robert Jirásko Prof. Dr. Roman Jambor Prof. Aleš Růžička Dr. Elena Rychagova Prof. Sergey Ketkov Prof. Libor Dostál 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(56):12884-12888
The reaction of N,C,N-chelated stibinidene ArSb ( 1 ) (Ar=C6H3-2,6-(CH=NtBu)2) with selected N-alkyl/aryl-maleimides RN(C(O)CH)2 (R=Me, tBu, Ph) gave the addition products with bridged bicyclic [2.2.1] structure containing an antimony atom at the bridgehead position, fused with a 6-membered benzene and a 5-membered N-alkyl/aryl-pyrrolidine ring. These compounds were completely characterized. More importantly, additional studies showed that these reactions are reversible in solution, thereby representing an unprecedented reversible activation of a C=C bond by an antimony(I) compound. 相似文献
2.
Jiríčková Kristína Gál Miroslav Krahulec Ján Híveš Ján 《Monatshefte für Chemie / Chemical Monthly》2015,146(5):755-759
Monatshefte für Chemie - Chemical Monthly - Basic biochemical properties such as Michaelis constant (K M), turnover number (k cat), and the ratio between these two kinetic parameters of enzyme... 相似文献
3.
Vít Kremláček Erik Kertész Prof. Zoltán Benkő Milan Erben Robert Jirásko Prof. Aleš Růžička Prof. Roman Jambor Prof. Libor Dostál 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(52):13096-13097
Invited for the cover of this issue are Zoltán Benkő, Libor Dostál and co-workers at the University of Pardubice and the Budapest University of Technology and Economics. The image depicts signs for the two different pathways representing the two differing reaction types which were clearly observed for 2,1-benzazaphosphole. Read the full text of the article at 10.1002/chem.202101686 . 相似文献
4.
Robert Jirásko Tomáš Mikysek Vitaliy Chagovets Ivan Vokřál Michal Holčapek 《Analytical and bioanalytical chemistry》2013,405(23):7181-7193
Ultrahigh-performance liquid chromatography coupled with high-mass-accuracy tandem mass spectrometry (UHPLC–MS–MS) has been used for elucidation of the structures of oxidation products of atorvastatin (AT), one of the most popular commercially available drugs. The purpose of the study was identification of AT metabolites in rat hepatocytes and comparison with electrochemically generated oxidation products. AT was incubated with rat hepatocytes for 24 h. Electrochemical oxidation of AT was performed by use of a three-electrode off-line system with a glassy carbon working electrode. Three supporting electrolytes (0.1 mol L?1 H2SO4, 0.1 mol L?1 HCl, and 0.1 mol L?1 NaCl) were tested, and dependence on pH was also investigated. AT undergoes oxidation by a single irreversible process at approximately +1.0 V vs. Ag/AgCl electrode. The results obtained revealed a simple and relatively fast way of determining the type of oxidation and its position, on the basis of characteristic neutral losses (NLs) and fragment ions. Unfortunately, different products were obtained by electrochemical oxidation and biotransformation of AT. High-mass-accuracy measurement combined with different UHPLC–MS–MS scans, for example reconstructed ion-current chromatograms, constant neutral loss chromatograms, or exact mass filtering, enable rapid identification of drug-related compounds. β-Oxidation, aromatic hydroxylation of the phenylaminocarbonyl group, sulfation, AT lactone and glycol formation were observed in rat biotransformation samples. In contrast, a variety of oxidation reactions on the conjugated skeleton of isopropyl substituent of AT were identified as products of electrolysis. Figure
Chemical structure of atorvastatin (AT) composed of four main parts assigned as A, B, C and D including the list of identified oxidation reactions for both electrochemical and in vitro experiments 相似文献
5.
M. Miglierini T. Kaňuch M. Pavúk P. Švec G. Schumacher I. Zizak Y. Jirásková 《Hyperfine Interactions》2008,183(1-3):31-35
As-quenched Fe91???x Mo8Cu1B x NANOPERM-type alloys (x?=?12, 15, 17, 20) were exposed to continuous heat treatment up to 800°C. During the temperature increase (ramp of 10 K/min), an in situ acquisition of diffracted synchrotron radiation intensities was performed. The obtained data are correlated with those derived from the volume and surface Mössbauer effect experiments. The onset of individual crystallization steps as well as identification of the crystalline phases created is discussed. 相似文献
6.
RGDS‐ and SIKVAVS‐Modified Superporous Poly(2‐hydroxyethyl methacrylate) Scaffolds for Tissue Engineering Applications 下载免费PDF全文
Hana Macková Zdeněk Plichta Vladimír Proks Ilya Kotelnikov Jan Kučka Helena Hlídková Daniel Horák Šárka Kubinová Klára Jiráková 《Macromolecular bioscience》2016,16(11):1621-1631
Three‐dimensional hydrogel supports for mesenchymal and neural stem cells (NSCs) are promising materials for tissue engineering applications such as spinal cord repair. This study involves the preparation and characterization of superporous scaffolds based on a copolymer of 2‐hydroxyethyl and 2‐aminoethyl methacrylate (HEMA and AEMA) crosslinked with ethylene dimethacrylate. Ammonium oxalate is chosen as a suitable porogen because it consists of needle‐like crystals, allowing their parallel arrangement in the polymerization mold. The amino group of AEMA is used to immobilize RGDS and SIKVAVS peptide sequences with an N‐γ‐maleimidobutyryloxy succinimide ester linker. The amount of the peptide on the scaffold is determined using 125I radiolabeled SIKVAVS. Both RGDS‐ and SIKVAVS‐modified poly(2‐hydroxyethyl methacrylate) scaffolds serve as supports for culturing human mesenchymal stem cells (MSCs) and human fetal NSCs. The RGDS sequence is found to be better for MSC and NSC proliferation and growth than SIKVAVS.
7.
The antioxidative activities of phenols derived from 2,6-di-tert. butyl-4-methylphenol (1) and 2,4-dimethyl-6-tert.butylphenol (and containing at position 4 or 2 to the hydroxyl group a substituent with the heteroatoms O, S or N) have been investigated. The highest activity was observed with the compounds of type (I) containing sulphur. The oxidation of isotactic polypropylene stabilized with all sulphur derivatives under investigation was clearly retarded even after the induction period. 相似文献
8.
S. Havlíček B. Million Y. Jirásková P. Michalička O. Schneeweiss 《Czechoslovak Journal of Physics》1997,47(5):575-579
Changes in the distribution of alloying elements and phase composition in the surroundings of the welding interface of two martensitic steels were studied by means of Conversion Electron Mössbauer Spectroscopy. It is shown that the redistribution of carbon due to its difference in chemical potentials in the individual steels is accompanied by fine changes in the phase composition detected. 相似文献
9.
L. Jiráčková-Audouin J.F. Bory J.F. Farrenq J. Verdu J. Pospíšil 《Polymer Degradation and Stability》1984,6(1):17-29
The influence of thiobisphenols, some products of their thermo-oxidative transformation and model compounds on the photo-oxidation of low density polyethylene (Ld PE) has been studied. Thiobisphenols are found to have a pro-oxidant effect in the early period of exposure, which increases with their concentration. On the other hand, the carbonyl build up was retarded in a later irradiation period. Similar effects have been observed with some thiobisphenol transformation products, bis(3,5-di-tert. butyl-4-hydroxybenzyl) sulphide and its oxidation products, sulphoxide and sulphone, respectively, and model 4,4′-methylenebis(2-methyl-6-tert. butylphenol). Dodecyl 3,3′-thiodipropionate retarded the carbonyl build up during the whole period of ultraviolet irradiation. Kinetic data show that a concentration of 0·1% by weight of thiobisphenols is the most effective in retarding the carbonyl build up in Ld PE films. The formation of non-alcoholic oxygenated structures seems to be a specific effect of the sulphur containing compounds under study. 相似文献
10.