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Detailed characterization of macrocyclic glycopeptide-based chiral stationary phases in SFC
Folprechtová, Denisa ; Kalíková, Květa (advisor) ; Křížek, Tomáš (referee) ; Kohout, Michal (referee)
The choice of a suitable chiral stationary phase is a key factor for successful enantioseparation in chromatographic methods. Macrocyclic glycopeptides are chiral selectors that, due to their unique structure, allow to interact with the analyte by various types of interactions simultaneously, which contributes to their complex retention and enantiodiscrimination mechanisms. Macrocyclic glycopeptides are widely used chiral stationary phases in liquid chromatography, but they have not been thoroughly tested in sub/supercritical fluid chromatography, which currently rank among important separation techniques in terms of chiral analyses. Therefore, the aim of this thesis is a detailed characterization of the enantiodiscrimination and retention mechanisms of macrocyclic glycopeptide-based chiral stationary phases packed with core-shell particles, namely TeicoShell, VancoShell, and NicoShell columns in sub/supercritical fluid chromatography. First, the effect of the mobile phase composition, especially the type and amount of organic modifiers and additives, on individual chromatographic parameters, i.e., retention, resolution of enantiomers, and peak shapes was studied in detail using selected sets of structurally different biologically active chiral compounds and materials. Based on the obtained...
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Enantioseparations of liquid crystalline materials
Vaňkátová, Petra ; Kubíčková, Anna (advisor) ; Čabala, Radomír (referee) ; Kohout, Michal (referee)
(EN) Liquid crystalline materials are an important domain of the material science. Chiral liquid crystals (CLCs) are researched for their unique chirality-derived properties. The development of new CLCs focuses both on appropriate molecular design to fit their intended purpose and also on ways of using widely available and less expensive sources of chirality to enable cost- effective production for a potential large-scale production. Methods capable of enantioseparation are needed mainly for chiral purity control of newly synthesized CLCs and for their potential use in scaling up for preparative purpose. Nowadays, enantioselective chromatography has evolved to be the method of choice for enantioseparations. This thesis aims to establish new approaches to chromatographic enantioseparations of CLCs by developing fast and robust enantioselective methods using two different ultra-high performance chromatographic techniques - sub/supercritical fluid chromatography (UHPSFC) and liquid chromatography (UHPLC). UHPSFC is introduced and successfully employed for the first time for this purpose. For some CLCs, high values of enantioselectivity and enantioresolution were achieved, opening the possibility of scaling up to semipreparative use. In UHPLC, two modes (reversed-phase and polar organic solvent mode)...
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Fluorescently labeled ligands for the Mu-opioid receptors
Hadzima, Martin ; Machara, Aleš (advisor) ; Kohout, Michal (referee)
This Bachelor's thesis deals with preparation of fluorescently labeled opiates, which allow detection of µ-opioid receptors and study of their interaction with ligands, using fluorescent techniques. As substrates designated for chemical modifications were chosen semi-synthetic opiates, naloxone and naltrexone. Their conversion to corresponding C-6 hydrazones allowed further modifications of these substances and tracking, if any changes to their ability to interact with µ-opioid receptors ocurr. Firstly, known adducts of these hydrazones with fluorescein isothiocyanate were prepared. Then, we inserted linkers of different lengths between the opiate fragment and the fluorescent tag, systematically. Mentioned linkers were prepared from tetraethyleneglycole derivatives with aim to study binding constants of modified µ-opioid receptor ligands. In the end, we decided to prepare opiate conjugate with particular linkers of length corresponding, approximately, to decaethyleneglycole. Two different procedures were proposed for the preparation of this linker. One of them used click chemistry concept and the other was based on classic amide coupling. Both conjugates were converted to adducts with fluorescein to verify their specific binding to µ-opioid receptors. They were also provided to co-operating group,...
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The Great depression in Czechoslovakia - economic development
Kohout, Michal ; Váňa, Daniel (advisor) ; Tajovský, Ladislav (referee)
The world economy has had in the 30th of the last century to deal with the challenge that the world has never seen. It was the Great Depression, which was started by the crash on the New York Stock Exchange in 1929 and had a major impact on functioning of almost all countries worldwide, Czechoslovakia was no exception. This bachelor thesis will focus on the economic impact of crisis on the world's most developed countries of that time. Then the thesis will deal with process of the Great Depression and the impact on the national economy of Czechoslovakia. The most important aim of this work is to find the process of the crisis ,the deepness ,impact on individual sectors and ultimately the grounds of the greatest economic crisis in modern history.
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