Národní úložiště šedé literatury Nalezeno 6 záznamů.  Hledání trvalo 0.01 vteřin. 
Application of In situ TR Spectroelectrochemical Techniques in Determination of Redox Mechanism of Bioactive Compounds
Sokolová, Romana ; Jiroušková, Eliška ; Degano, I. ; Wantulok, J. ; Nycz, J.
The electron transfer reactions play an important role in many natural processes. Reactions such as \ndissociation, protonation, and reactions with water and other small molecules often occur in \nbiotransformation. The reaction schemes involving these chemical reactions coupled to the \nelectron transfer can be determined by cyclic voltammetry. Additionally, in \nsitu spectroelectrochemistry can efficiently contribute to the determination of oxidation or \nreduction mechanism. This technique provides information about the electroactive chromophore during \nthe redox process allowing to identification the first reaction intermediates. The final reaction \nproducts were identified by chromatographic techniques. This study represents a key role of TR \nspectroelectrochemistry in the determination of reaction intermediates in the case of \n1,10- phenanthroline derivative substituted by bioactive phenothiazine unit and \ndrug 3- fluorophenmetrazine (2-(3-fluorophenyl)-3-methylmorpholine, 3-FPM). Co pound 3-FPM\nhave recently appeared as the new psychoactive substance in the drug market.\n
Spectroelectrochemistry of 1,10-phenantrolines Substituted by Pyrrolidine and Phenothiazine Redox-active Units
Sokolová, Romana ; Wantulok, J. ; Fiedler, Jan ; Nycz, J. ; Degano, I.
Compounds based on 1,10-phenanthroline (Phen) and their complexes are used in many fields, such as a stabilizing agent in the synthesis of nanoparticles, catalysts in homogeneous catalysis and as a semiconductor in organic light-emitting diodes (OLED) due to their coordination abilities. In this work, 1,10-phenanthrolines functionalized by pyrrolidine and phenothiazine units were studied by electrochemical methods. Cyclic voltammetry resulted in several oxidation and reduction voltammetric peaks. Structure-activity relationship was investigated using in situ spectroeletrochemistry, spectrophotometry, infrared spectroscopy and chromatography.
Oxidation and Reduction of Selected 1,10-Phenantrolines
Wantulok, J. ; Sokolová, Romana ; Nycz, J. E. ; Degano, I.
Derivatives of 1,10-phenanthroline (Phen) are well-known bident ligands which had a lot of interesting applications thanks to their coordination abilities. Selected 1,10-phenanthroline compounds were studied by electrochemical methods. Depending on their different substituents were observed several oxidation and reduction voltammetric peaks. The study involves also in situ spectroeletrochemistry, infrared spectroscopy and identification of products by HPLC-DAD and HPLC-ESI MS/MS.
Oxidation Mechanism of Rhamnetin, a Bioflavonoid Compound
Ramešová, Šárka ; Sokolová, Romana ; Degano, I.
The natural flavonoid rhamnetin (2-(3,4-dihydroxyfenyl)-3,5-dihydroxy-7-methoxychromen-4-one) is important bioactive compound. Rhamnetin was studied in aqueous solution by electrochemical methods. The oxidation mechanism proceeds in sequential steps, which correspond to the hydroxyl oxidation of groups in the three aromatic rings. The study is based on in situ spectroelectrochemistry and identification of products by HPLC-DAD and HPLC–ESI MS/MS.
Oxidation Mechanisms of Diflunisal on Glassy Carbon Electrode
Tiribilli, Ch. ; Giannarelli, S. ; Sokolová, Romana ; Valášek, M.
The electrochemical oxidation of diflunisal in acetonitrile was studied on a glassy carbon electrode. Diflunisal yields one irreversible oxidation wave at 1.6 V (vs. Ag/AgCl/1M LiCl electrode). The oxidation mechanism depends on the basicity of the solvent. The study is based on cyclic voltammetry, electroanalytical methods and UV-Vis spectroelectrochemistry. The degradation products were determined by separation techniques (HPLC-DAD, GC-MS).
Elektrochemická studie rhamnazinu
Ramešová, Šárka ; Sokolová, Romana ; Degano, I.
Rhamnazin (3,5,4’-trihydroxy-7,3’-dimethoxyflavone) patří do skupiny přirozeně se vyskytujících bioflavonoidů. Flavonoidy jsou zpravidla syntetizovány rostlinami a jsou hlavními chromofory ve většině používaných žlutých barviv 1. Flavonoidy byly využívány k barvení tapiserií a dalších historických předmětů již v 16. století 2. Rhamnazin je široce rozšířený v přírodě, především v ovoci, zelenině a čajích 3,4. Tato sloučenina je známá pro své terapeutické účinky, užívá se jako preventivní léčivo při kardiovaskulárních onemocněních, rakovině a hepatitidě 5,6.