National Repository of Grey Literature 5 records found  Search took 0.00 seconds. 
Study of thiol addition to biliverdine, the synthesis of labelled bilirubine
Felklová, Veronika ; Lešetický, Ladislav (advisor) ; Smrček, Stanislav (referee)
Biliverdin and bilirubin are bile pigments which are degradation products of heme. Biliverdin (BV) is greenish-blue pigment and is reduction product of tetrapyrrolic core of heme by influence of the hemoxygenase (HO). The final product of this degradation is yellowish-brown pigment bilirubin (BR) which forms from BV thanks to the biliverdinreduktase (BVR). Normal and slightly raised level of bilirubin in plasma has cytoprotective effects whereas high levels are cytotoxic often. In severe unconjugated hyperbilirubinemia cases (newborn children) unconjugated bilirubin (UCB) accumulates in central nervous system (CNS) and causes bilirubin-induced neurologic dysfunction (BIND). Unfortunately there is a limitation for finding UCB pathophysiology caused by difficult determination of UCB content and distribution in tissues and biological fluids. So the main purpose of this thesis is to find and integrate isolated methods which will serve as the basis of finding bilirubin distribution. This progress would have a significant effect on studies of bilirubin neurotoxicity on newborn children. This method is based on radioactive labeling of UCB. Preferentially atom C 10 used for binding suitable functional group (thiols) because conformation of indicated bilirubin shouldn't change in this position. And then the...
Synthesis and applications of fluorophosphonates
Cherkupally, Prabhakar ; Beier, Petr (advisor) ; Hermann, Petr (referee) ; Kvíčala, Jan (referee)
In the Introduction part of this thesis, the chemistry of organo-fluorine compounds including the electronic properties that fluorine impacts onto organic molecules, steric effects, lipophilicity and other characteristics as well as applications and important features of organo-fluorine compounds are briefly discussed. Moreover, summary of the methods for their preparation, modern methods for fluorinations and enantioselective fluorinations, and fluoroalkylation methodologies in organic synthesis are described. Additionally, the chemistry of fluorinated phosphonates including their preparations, important applications and the chemistry of α,α-difluorophosphonates are discussed. The Results and discussion part describes nucleophilic trifluoromethylation of various electrophilic substrates using diethyl trifluoromethylphosphonate. Furthermore, efficient stereoselective synthesis of fluorovinylphosphonates by a base-induced HF elimination of α,α-difluorophosphonates is explained. In addition, synthesis of number of new, structurally diverse compounds, having a difluorophosphonate moiety using the reaction of diethyl difluoromethylphosphonate with various α,β-unsaturated carbonyl compounds, Michael acceptors and imines are reported. Also, preliminary experiments dealing with nucleophilic reactions of...
Sulfur-based reagents for nucleophilic and radical introduction of tetrafluoroethyl and tetrafluoroethylene groups
Chernykh, Yana ; Beier, Petr (advisor) ; Kvíčala, Jaroslav (referee) ; Církva, Vladimír (referee)
Charles University in Prague, Faculty of Science Department of Organic Chemistry Ing. Yana Chernykh Sulfur-Based Reagents for Nucleophilic and Radical Introduction of Tetrafluoroethyl and Tetrafluoroethylene Groups Ph.D. Thesis Prague 2014 ABSTRACT This project was aimed at developing new methodologies for selective introduction of tetrafluoroethyl and tetrafluoroethylene groups into organic molecules. The study was focused on reactivities of fluorinated sulfones and sulfides as tetrafluoroalkylation reagents. In the Introduction part of the thesis, main aspects of organofluorine chemistry are outlined, illustrating beneficial effects of fluorine atoms on physical, chemical and biological properties of organic compounds. General synthetic methods for the selective introduction of fluorine atoms and fluoroalkyl groups to organic molecules are described. Particular attention is given to reactivity and applications of CF2CF2-containing compounds, indicating challenges in synthetic approaches toward tetrafluoroalkylation. The Results and discussion part describes reactivities of four new fluorinated organosulfur reagents as tetrafluoroethyl and tetrafluoroethylene building blocks. The application of these reagents as various carbanionic or radical synthons proved to be effective for the incorporation of CF2CF2...
Synthesis and applications of fluorophosphonates
Cherkupally, Prabhakar ; Beier, Petr (advisor) ; Hermann, Petr (referee) ; Kvíčala, Jan (referee)
In the Introduction part of this thesis, the chemistry of organo-fluorine compounds including the electronic properties that fluorine impacts onto organic molecules, steric effects, lipophilicity and other characteristics as well as applications and important features of organo-fluorine compounds are briefly discussed. Moreover, summary of the methods for their preparation, modern methods for fluorinations and enantioselective fluorinations, and fluoroalkylation methodologies in organic synthesis are described. Additionally, the chemistry of fluorinated phosphonates including their preparations, important applications and the chemistry of α,α-difluorophosphonates are discussed. The Results and discussion part describes nucleophilic trifluoromethylation of various electrophilic substrates using diethyl trifluoromethylphosphonate. Furthermore, efficient stereoselective synthesis of fluorovinylphosphonates by a base-induced HF elimination of α,α-difluorophosphonates is explained. In addition, synthesis of number of new, structurally diverse compounds, having a difluorophosphonate moiety using the reaction of diethyl difluoromethylphosphonate with various α,β-unsaturated carbonyl compounds, Michael acceptors and imines are reported. Also, preliminary experiments dealing with nucleophilic reactions of...
Study of thiol addition to biliverdine, the synthesis of labelled bilirubine
Felklová, Veronika ; Lešetický, Ladislav (advisor) ; Smrček, Stanislav (referee)
Biliverdin and bilirubin are bile pigments which are degradation products of heme. Biliverdin (BV) is greenish-blue pigment and is reduction product of tetrapyrrolic core of heme by influence of the hemoxygenase (HO). The final product of this degradation is yellowish-brown pigment bilirubin (BR) which forms from BV thanks to the biliverdinreduktase (BVR). Normal and slightly raised level of bilirubin in plasma has cytoprotective effects whereas high levels are cytotoxic often. In severe unconjugated hyperbilirubinemia cases (newborn children) unconjugated bilirubin (UCB) accumulates in central nervous system (CNS) and causes bilirubin-induced neurologic dysfunction (BIND). Unfortunately there is a limitation for finding UCB pathophysiology caused by difficult determination of UCB content and distribution in tissues and biological fluids. So the main purpose of this thesis is to find and integrate isolated methods which will serve as the basis of finding bilirubin distribution. This progress would have a significant effect on studies of bilirubin neurotoxicity on newborn children. This method is based on radioactive labeling of UCB. Preferentially atom C 10 used for binding suitable functional group (thiols) because conformation of indicated bilirubin shouldn't change in this position. And then the...

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