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Mixture toxicity of estrogenic endocrine disruptors in samples from the Czech Republic
Černá, Tereza ; Cajthaml, Tomáš (advisor) ; Klusoň, Petr (referee) ; Šváb, Marek (referee)
The environment is contaminated by countless toxic chemicals of mainly anthropogenic origin; therefore, elucidating the impact of chemical mixtures is one of the biggest challenges of current research. Endocrine disruptors (EDs) acting through the oestrogenic nuclear receptor are typical representatives of the mixture toxicity concept of concentration addition, which can be accurately predicted using the latest mathematical models. Oestrogenic activity and oestrogenic EDs have been detected in many matrices across the globe in biologically relevant concentrations; therefore, they are considered a high risk. The presence of synthetic steroids in the aquatic environment in units of ng/l can disrupt the hormonal pathways of individuals and subsequently cause fatal changes in whole populations. However, if the exposure is terminated, the ecosystem will recover in a few years. Wastewater treatment plants (WWTPs) are able to remove a large number of chemicals, including synthetic and natural oestrogenically active compounds; nevertheless, their occurrence in WWTP effluents and in sewage sludges is frequent. Therefore, WWTPs are considered significant sources of agricultural and water ecosystem pollution. This dissertation thesis focuses on the mixture toxicity of oestrogenic EDs and their occurrence in...
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Alkaloids of Narcissus'Dutch Master ' (Amaryllidaceae) and their biological activity. II.
Dvořáková, Zdeňka ; Chlebek, Jakub (advisor) ; Ločárek, Miroslav (referee)
Dvořáková Zdeňka: Alkaloids of Narcissus 'Dutch Master' (Amaryllidaceae) and their biological activity II. Diploma thesis 2016, Charles University in Prague, Faculty of Pharmacy in Hradec Králové, Department of Pharmaceutical Botany and Ecology. The content of this work was isolation of compounds from the selected fraction ND-6 obtained by column chromatography of Narcissus 'Dutch Master' alkaloid extract. Preparation of extract and its column chromatography was performed by Mrg. Daniela Hulcová as part of her doctoral studies. By the means preparative TLC was from fraction ND- 6 homolycorine type alkaloid (+)-O-methyllycorenine gained. Its structure was determined on the basis NMR, GC-MS analysis and optical rotation. The obtained data were compared with facts in known literature. By the isolated alkaloid was determined its cholinesterase inhibitory activity against acetylcholinesterase and butyrylcholinesterase. Its inhibitory activity was expressed as IC50 (M) and compared with known standards galanthamine, physostigmine, and Huperzine A. This alkaloid is inactive against cholinesterase (IC50 AChE > 1000 M, IC50 BChE > 1000 M). On the basis of gained results, we can evaluate this alkaloid from the point of view of cholinesterase inhibition as potentially unusable in the treatment of AD. Key...
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Alkaloids of Narcissus 'Dutch Master '(Amaryllidaceae) and their biological activity. I.
Vacková, Lucie ; Chlebek, Jakub (advisor) ; Hošťálková, Anna (referee)
Vacková, L.: Alkaloids Narcissus 'Dutch Master' (Amaryllidaceae) and their biological activity. I. Diploma thesis, Charles University in Prague, Faculty of Pharmacy in Hradec Králové, Department of Pharmaceutical Botany and Ecology, Hradec Králové 2016. From a selected fraction ND-6, which was obtained by column chromatography of an alkaloid extract of Narcissus 'Dutch Master' (preparation of the alkaloid extract and column chromatography was performed by Mgr. Daniela Hulcová within her doctoral thesis), lycorine alakloid O-acetylpluviin was isolated using preparative TLC. Its structure was determined on the basis of MS, NMR analysis, and optical rotation, the obtained data were compared with the literature. The isolated alkaloid was tested on its possibility to inhibit human acetylcholinesterase and butyrylcholinesterase. The activity was expressed as IC 50 values (IC50 AChE = 648.03 ± 53.95 μM, IC50 BChE = 602.50 ± 48.50 μM) and compared with IC50 values of galanthamine, huperzine A and physostigmine. O-acetylpluviine showed a very low inhibitory cholinesterase activity, and so, the alkaloid does not seem to be a suitable cholinesterase inhibitor for potential use in the treatment of Alzheimer's disease. Keywords: Narcissus 'Dutch Master', Amaryllidaceae, lycorine alkaloids, Alzheimer's disease,...
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Alkaloids of Narcissus'Dutch Master ' (Amaryllidaceae) and their biological activity. II.
Dvořáková, Zdeňka ; Chlebek, Jakub (advisor) ; Ločárek, Miroslav (referee)
Dvořáková Zdeňka: Alkaloids of Narcissus 'Dutch Master' (Amaryllidaceae) and their biological activity II. Diploma thesis 2016, Charles University in Prague, Faculty of Pharmacy in Hradec Králové, Department of Pharmaceutical Botany and Ecology. The content of this work was isolation of compounds from the selected fraction ND-6 obtained by column chromatography of Narcissus 'Dutch Master' alkaloid extract. Preparation of extract and its column chromatography was performed by Mrg. Daniela Hulcová as part of her doctoral studies. By the means preparative TLC was from fraction ND- 6 homolycorine type alkaloid (+)-O-methyllycorenine gained. Its structure was determined on the basis NMR, GC-MS analysis and optical rotation. The obtained data were compared with facts in known literature. By the isolated alkaloid was determined its cholinesterase inhibitory activity against acetylcholinesterase and butyrylcholinesterase. Its inhibitory activity was expressed as IC50 (M) and compared with known standards galanthamine, physostigmine, and Huperzine A. This alkaloid is inactive against cholinesterase (IC50 AChE > 1000 M, IC50 BChE > 1000 M). On the basis of gained results, we can evaluate this alkaloid from the point of view of cholinesterase inhibition as potentially unusable in the treatment of AD. Key...
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