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The copper - chelating activity of xanthen-3-ones derivates
Uramová, Daniela ; Mladěnka, Přemysl (advisor) ; Smutná, Lucie (referee)
Charles University Faculty of Pharmacy in Hradec Králové Department of Pharmacology & Toxicology Student: Daniela Uramová, MSc. Supervisor: Prof. Přemysl Mladěnka, Pharm.D., Ph.D. Title: The copper - chelating activity of xanthen-3-ones derivates As a biogenic element, copper participates in many metabolic processes in the human body, it is a part of several enzymes, and its presence is therefore essential for life. On the other hand, free atoms of copper increase the formation of free radicals, and hence copper can be toxic to the body. Therefore, current research has being testing several substances that could be able to interact with copper ions and thus affect its dyshomeostasis in the body. Polyphenolic xanthones seem interesting, as they possess in addition to these properties also show other positive effects. The aim of this work was to evaluate the copper-chelating activity of ten closely structurally related synthetic derivates of xanthen-3-ones. The spectrophotometric measurement was carried out in vitro using the hematoxylin and bathocuproine method. 2,6,7-trihydroxy-xanthene-3-one derivates were shown to be able to chelate copper at all tested pH conditions (5.5; 6.8 and 7.5). However, in a more competitive environment, the resulting complexes are unstable. In some cases, it was...
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Pharmacokinetics of flavanones
Uramová, Daniela ; Mladěnka, Přemysl (advisor) ; Spilková, Jiřina (referee)
Charles University Faculty of Pharmacy in Hradec Králové Department of Pharmacology & Toxicology Student: Daniela Uramová Supervisor: Assoc. Prof. Přemysl Mladěnka, Pharm.D., Ph.D. Title of diploma thesis: Pharmacokinetics of flavanones The aim of the work was to summarize the available information regarding the fate of the flavanones in the human organism. These flavonoids are a common part of human diet, and therefore oral administration is the most relevant and examined. There are many obstacles in the digestive tract which are lowering their absorption. Flavanones in human food occur mainly in the form of glycosides, and therefore must be deglycosylated by the β- glucosidase enzyme family. Aglycones are absorbed mainly in the small intestine. Flavonoids in the form of non-cleavable glycosides (e.g., rutinosides) are absorbed in the distal parts of the digestive system, after cleavage of the sugar component by intestinal bacteria. They also decompose the flavanone ring. This leads to substances with a phenylpropionic structure which can be absorbed. In general, flavanones are subject to extensive metabolism by cytochrome P450, not only in the liver but also in the enterocytes, which greatly limits their bioavailability. They are also rapidly conjugated with glucuronic or sulfuric acid. The...
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