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The design and synthesis of selective copper(II) chelators
Havlík, Jan ; Kotek, Jan (advisor) ; Holzhauser, Petr (referee)
Title: Design and synthesis of selective copper(II) chelators Author: Jan Havlík Department: Department of Inorganic Chemistry, Faculty of Science Supervisor: assoc. prof. RNDr. Jan Kotek, Ph.D. Supervisor's e-mail address: modrej@natur.cuni.cz The aim of this work was to prepare selective copper(II) chelators. Within the frame of this thesis were synthesized 13 compounds, from which 7 are new. All compounds were fully characterized by NMR spectroscopy and mass spectrometry. Copper(II) complex of synthesized ligand 1,11-bis(methylphosphinic acid)cyclam, (1,11-dipin), was studied in thermodynamic and formation/decomplexation studies. For 1,11-dipin-copper(II) complex were determined values of rate constants and activation parameters. Keywords: selective chelator, copper, cyclam derivatives, macrocyclic ligands, methylphosphonate, methylphosphinate
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Are currently used chelators of heavy metals also chelators of calcium and magnesium?
Skoupilová, Karolína ; Mladěnka, Přemysl (advisor) ; Šuťák, Róbert (referee)
Charles University Faculty of Pharmacy in Hradec Králové Department of Pharmacology and Toxicology Candidate: Karolína Skoupilová Supervisor: prof. Přemysl Mladěnka, Pharm.D., Ph.D. Title of diploma thesis: Are currently used chelators of heavy metals also chelators of calcium and magnesium? Calcium and magnesium are important elements for the human body. Calcium plays an important role in blood clotting and intracellular signalling, thus participating in muscle contraction and platelet aggregation, among other processes. Magnesium is a cofactor for many enzymes. A significant deficiency of both ions can manifest as disorders of heart rhythm and increased neuromuscular excitability. The aim of this study was to determine the chelating activity of currently used heavy metal chelators and to determine the stability of the indicator. First, the ideal pH for the experiment was determined. In the next step, the chelation rate of 21 known metal chelators was measured using an in vitro spectrophotometric method. Finally, the chelation of the most active calcium chelators was verified on platelet aggregation in a human blood sample. At the same time, the long-term stability of the indicator o- cresolphthalein complexone (CC) was determined. In the first step, pH 7.5 was chosen, which was the only one...
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Chelation of copper ions by thiol containing chelators
Kladivová, Andrea ; Mladěnka, Přemysl (advisor) ; Carazo Fernández, Alejandro (referee)
Charles University Faculty of Pharmacy in Hradec Králové Department of Pharmacology & Toxicology Student: Andrea Kladivová Consultant: Václav Tvrdý, MSc. Supervisor: Assoc. Prof. Přemysl Mladěnka, PharmD., Ph.D. Title of diploma thesis: Chelation of copper ions by thiol containing chelators Copper is an essential trace element that is important for many physiological functions. On the other hand, disruption of copper homeostasis associated with its elevated level is dangerous for the organism, because of the formation of free radicals. Copper chelators can represent an effective tool in the treatment of such conditions. Due to the ability of a thiol group to bind metal ions and form a chelate, thiol containing chelators are promising compounds for the reduction of copper levels. Within this diploma thesis, four compounds containing a thiol group were tested for the ability to chelate copper ions. Spectrophotometric measurement was used for this determination. It is a simple, fast but precise method for determination of the chelation properties in vitro. In addition, the ability of these compounds to reduce cupric ions was examined. When using the basic hematoxylin method, all the tested substances proved they can chelate copper. Their efficacy was practically identical except for the...
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Chelating Polymers for the Haemochromatosis Treatment
Groborz, Ondřej ; Hrubý, Martin (advisor) ; Kotek, Jan (referee)
5 Chelating Polymers for the Haemochromatosis Treatment Author: Ondřej Groborz Tutor: Mgr. Martin Hrubý, Ph.D., DSc. Advisors: Ing. Kristýna Kolouchová Ing. Pavel Švec Institute of Macromolecular Chemistry, Czech Academy of Sciences Abstract Haemochromatosis is a group of hereditary diseases which are characterised by toxic accumulation of iron in parenchymal organs, leading to organ toxicity and irreversible damage. Currently, there are only a few approved medications for this disease, yet all of them possess severe side effects. Herein, we have proposed a new paradigm for treatment: insoluble polymers with negligible systemic biological availability would form stable complexes with iron ions in the gastrointestinal tract, hence decreasing biological availability of iron. The insolubility of polymers prevents them from being absorbed into the organism in the first place while having no systemic side effects or toxicity. We have prepared polymers with several covalently bound iron-chelating ligands and based on the biological data we selected the most successful chelators for possible future applications. These polymers exhibited negligible resorbability and toxicity, superior in vitro iron chelating activity and their efficacy was proven in an in vivo model. Therefore they could be used as a...
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Ability of copper chelators to interact with iron and zinc
Hanuščinová, Lucia ; Mladěnka, Přemysl (advisor) ; Čonka, Patrik (referee)
Charles University Faculty of Pharmacy in Hradec Králové Department of Pharmacology and Toxicology Student: Lucia Hanuščinová Supervisor: Assoc. Prof. Přemysl Mladěnka, PharmDr., PhD. Title of diploma thesis: Ability of copper chelators to interact with iron and zinc Copper plays in the human organism a role of an element with indispensable significance, whose biological influence and effects depend on its quantity. With elevated concentrations in the human body, copper becomes toxic, resulting in pathological conditions. The most well-known diseases is the Wilson's disease, whose treatment consists of oral administration of chelators, i.e. chemical compounds, which are capable of binding copper ions in various proportions and eliminating them from the organism. Chelation therapy is currently the first choice after confirmation of the diagnosis. Chelation toxicity results from several factors, e.g. inhibition of copper dependent enzymes or low selectivity to metals. And precisely the selectivity of chelators is being discussed in this diploma thesis. An ideal chelator should not interact with any of the other physiological ions, that are necessary for the proper functioning of the organism. Five of the most frequently therapeutically or experimentally used substances /trientine, D-penicillamine,...
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Chelation of copper ions by thiol containing chelators
Kladivová, Andrea ; Mladěnka, Přemysl (advisor) ; Carazo Fernández, Alejandro (referee)
Charles University Faculty of Pharmacy in Hradec Králové Department of Pharmacology & Toxicology Student: Andrea Kladivová Consultant: Václav Tvrdý, MSc. Supervisor: Assoc. Prof. Přemysl Mladěnka, PharmD., Ph.D. Title of diploma thesis: Chelation of copper ions by thiol containing chelators Copper is an essential trace element that is important for many physiological functions. On the other hand, disruption of copper homeostasis associated with its elevated level is dangerous for the organism, because of the formation of free radicals. Copper chelators can represent an effective tool in the treatment of such conditions. Due to the ability of a thiol group to bind metal ions and form a chelate, thiol containing chelators are promising compounds for the reduction of copper levels. Within this diploma thesis, four compounds containing a thiol group were tested for the ability to chelate copper ions. Spectrophotometric measurement was used for this determination. It is a simple, fast but precise method for determination of the chelation properties in vitro. In addition, the ability of these compounds to reduce cupric ions was examined. When using the basic hematoxylin method, all the tested substances proved they can chelate copper. Their efficacy was practically identical except for the...
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Tumor suppressor NDRG1 and its regulation by iron chelators
Vondráčková, Michaela ; Truksa, Jaroslav (advisor) ; Brábek, Jan (referee)
Iron is an essential trace element required for many processes within a cell, including DNA synthesis and cell cycle progression. Moreover, it is critical for cellular respiration in mitochondria. Due to their proliferative nature, cancer cells are dependent on iron, and depleting this element via iron chelators results in the inhibition of ribonucleotide reductase, leading to cell cycle arrest and apoptosis of cancer cells. Recently, an alternative mechanism for the effect of iron chelators have been proposed, including induction of N-myc downstream regulated gene 1 (NDRG1) expression and its inhibitory effect on c-MET, EGFR, and NF-κB pathways, which can act as oncogenes in a certain context. NDRG1 is a tumour suppressor gene, which is downregulated in many cancers and its downregulation correlates with cancer progression, poor differentiation, and higher metastatic potential. It has been shown that NDRG1 expression can be regulated by intracellular iron - a decrease in intracellular iron leads to upregulation of NDRG1 at mRNA and protein level via the HIF-1-dependent mechanism by inhibiting prolyl hydroxylases. Recently, we have conceived the concept of mitochondrially targeted chelators as an effective anti-cancer agent and in this work, we focused on the evaluation of mitochondrially targeted...
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Chelation of copper ions by thiol containing chelators
Kladivová, Andrea ; Mladěnka, Přemysl (advisor) ; Carazo Fernández, Alejandro (referee)
Charles University Faculty of Pharmacy in Hradec Králové Department of Pharmacology & Toxicology Student: Andrea Kladivová Consultant: Václav Tvrdý, MSc. Supervisor: Assoc. Prof. Přemysl Mladěnka, PharmD., Ph.D. Title of diploma thesis: Chelation of copper ions by thiol containing chelators Copper is an essential trace element that is important for many physiological functions. On the other hand, disruption of copper homeostasis associated with its elevated level is dangerous for the organism, because of the formation of free radicals. Copper chelators can represent an effective tool in the treatment of such conditions. Due to the ability of a thiol group to bind metal ions and form a chelate, thiol containing chelators are promising compounds for the reduction of copper levels. Within this diploma thesis, four compounds containing a thiol group were tested for the ability to chelate copper ions. Spectrophotometric measurement was used for this determination. It is a simple, fast but precise method for determination of the chelation properties in vitro. In addition, the ability of these compounds to reduce cupric ions was examined. When using the basic hematoxylin method, all the tested substances proved they can chelate copper. Their efficacy was practically identical except for the...
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Screening of novel chelators of microbiogenic metals
Catapano, Maria Carmen ; Mladěnka, Přemysl (advisor) ; Hrdina, Radomír (referee) ; Musiol, Robert (referee)
Charles University, Faculty of Pharmacy in Hradec Králové Department of Pharmacology and Toxicology Candidate: Maria Carmen Catapano, MSc. Supervisor: Assoc. Prof. Přemysl Mladěnka, PharmD., Ph.D. Co-supervisor: Assoc. Prof. Laura Mercolini, Ph.D. Title of Doctoral Thesis: Screening of novel chelators of microbiogenic metals Iron, copper and zinc are microbiogenic elements which play crucial roles in a series of physiological processes in human organism. Homeostasis of these transition metals is strictly regulated since, among others: a) free or loosely bound iron or copper can catalyse the production of hydroxyl radical; b) lack of zinc but also of the previously mentioned metals is associated with significant impairments. Hereditary hemochromatosis, transfusion-induced secondary iron overload and Wilson's disease are known as pathological conditions associated with metal overload in the organism. Chelator agents have vital relevance for the treatment of these impairments. There are also numerous diseases with homeostatic imbalances in iron, copper and or zinc: neurodegenerative diseases, cardiovascular diseases, cancer and diabetes mellitus. Different chelating compounds have been examined for the treatment of these impairments. The aim of this doctoral thesis was to perform a screening of metal...
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Chelating Polymers for the Haemochromatosis Treatment
Groborz, Ondřej ; Hrubý, Martin (advisor) ; Kotek, Jan (referee)
5 Chelating Polymers for the Haemochromatosis Treatment Author: Ondřej Groborz Tutor: Mgr. Martin Hrubý, Ph.D., DSc. Advisors: Ing. Kristýna Kolouchová Ing. Pavel Švec Institute of Macromolecular Chemistry, Czech Academy of Sciences Abstract Haemochromatosis is a group of hereditary diseases which are characterised by toxic accumulation of iron in parenchymal organs, leading to organ toxicity and irreversible damage. Currently, there are only a few approved medications for this disease, yet all of them possess severe side effects. Herein, we have proposed a new paradigm for treatment: insoluble polymers with negligible systemic biological availability would form stable complexes with iron ions in the gastrointestinal tract, hence decreasing biological availability of iron. The insolubility of polymers prevents them from being absorbed into the organism in the first place while having no systemic side effects or toxicity. We have prepared polymers with several covalently bound iron-chelating ligands and based on the biological data we selected the most successful chelators for possible future applications. These polymers exhibited negligible resorbability and toxicity, superior in vitro iron chelating activity and their efficacy was proven in an in vivo model. Therefore they could be used as a...
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