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Role of brassinosteroids in plant response to drought stress
Trubanová, Nina ; Rothová, Olga (advisor) ; Urban, Milan (referee)
Brassinosteroids are steroid phytohormones with a wide range of effects. They improve survivance of plants exposed to drought stress, increase their resistence and yield therethrough. They regulate the response of plants directly (via synthesis of metabolits) and/or indirectly (via the induction of antioxidant compounds and enzymes), often in interaction with other phytohormones. Experiments studying influence of brassinosteroids on response of plants stressed with water deficit differ in several parameters. Their correct interpretation is complicated conseguently.
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Development of a general and modular approach to C-nucleosides
Kubelka, Tomáš ; Štefko, Martin ; Bárta, Jan ; Joubert, Nicolas ; Urban, Milan ; Chapuis, Hubert Jean ; Hocek, Michal
Highly efficient and modular approach was developed for the synthesis of various types of new (het)aryl C-nucleosides. This protocol consists of the synthesis of haloaryl-C-nucleoside intermediates, followed by a functional group transformation to introduce various substituents. Using this approach protected 2′-deoxy-C-nucleosides bearing halogenated benzene, pyridine, thiophene, furane and pyrimidine were prepared. These intermediates were then submitted to a wide range of palladium-catalyzed reactions. The same approach was also used for preparation of C-nucleosides bearing ribofuranose moiety. Functional ribofuranosides bearing diverse substituted pyridine and benzene nucleobases were prepared in this way.
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Modulární metodiky pro přípravu různých aryl C-2'-deoxyribonukleosidů
Joubert, Nicolas ; Bárta, Jan ; Urban, Milan ; Hocek, Michal
A modular methodology for the syntheses of various substituted aryl C-2´-deoxyribonucleosides has been developed. In each series, a larger scale synthesis of a versatile halogenated C-nucleoside intermediate has been accomplished, followed by its use for a generation of diverse derivatives by displacement of the halogen for alkyl, aryl or amino substituents by cross-coupling or amination reactions. Subsequent deprotection gave the final desired C-2´-deoxyribonucleosides. This methodology has been applied for the development of modular syntheses of 4- or 3-substituted benzene C-nucleosides, 6-substituted pyridin-2-yl C-nucleosides, 6-substituted pyridin-3-yl C-nucleosides and 5-substituted thiophen-2-yl C-nucleosides.
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