National Repository of Grey Literature 137 records found  1 - 10nextend  jump to record: Search took 0.01 seconds. 
Stability evaluation of magnesium complexes of phthalocyanines and azaphthalocyanines under acidic conditions
Mulaku, Anita ; Zimčík, Petr (advisor) ; Miletín, Miroslav (referee)
Charles University, Faculty of Pharmacy in Hradec Králové Department of Pharmaceutical Chemistry and Pharmaceutical Analysis Candidate: Anita Mulaku Supervisor: Assoc. Prof. Petr Zimčík, Ph.D. Title of Diploma Thesis: Stability evaluation of magnesium complexes of phthalocyanines and azaphthalocyanines under acidic conditions Phthalocyanines are categorized as analogues of porphyrin where the structures is based on four isoindoline units condensed via a nitrogen atom. Alongside subphthalocyanines, these compounds are attracting attention as useful dyes that find application in photodynamic therapy, organic electronic devices, organic solar cells and other areas. Phthalocyanines are capable of forming complexes with different types of metal and can be used in fluorescence probing due to their suitable absorption and emission in the red region of the visible spectrum. Red or near-infrared excitation and emission is important for biological applications since longer wavelength light penetrates deeper into tissues, it is less scattered and the autofluorescence of endogenous chromophores is limited. The photophysical and photochemical properties of phthalocyanines and their analogues depend highly on the central metal and peripheral substitution. The magnesium complexes are highly suitable for the...
Oxadiazoles as potential drugs II.
Kolčárková, Lucie ; Kučerová, Marta (advisor) ; Zimčík, Petr (referee)
Charles University, Faculty of Pharmacy in Hradec Králové Department of Pharmaceutical Chemistry and Pharmaceutical Analysis Candidate: Kolčárková Lucie Supervisor: PharmDr. Marta Kučerová, Ph.D. Title of diploma thesis: Oxadiazoles as Potential Drugs II. My work was focused on finding new potential drugs with antibacterial and antifungal activity, from the reason of increasing microbial resistance against current drugs. 3-Pyrazin-2-yl-1,2,4-oxadiazole was chosen as the structural scaffold for the research. In the theoretical part of this diploma thesis I have reviewed various procedures of the preparation of 1,2,4-oxadiazoles. The methods of preparation have been assorted according to the starting material used. In the experimental part of this study several different ways of preparation to synthesize these compounds were explored and then improvement of reaction conditions in order to gain the pure product in good yields were tested. None of compounds has been reported so far. They have been characterized by IR and NMR spectra and by melting points as well. Their purity was checked by TLC and elemental analysis. Six of the synthesized compounds have been tested in vitro for their antibacterial and antifungal activity. One of the compounds has shown medium antifungal activity and another one has...
Derivatives combining the fragment of pyrazinamide and 4-aminosalicylic acid as antimycobacterial compounds
Šlechta, Petr ; Zitko, Jan (advisor) ; Zimčík, Petr (referee)
Charles University Faculty of Pharmacy in Hradec Králové Department of Pharmaceutical chemistry and Pharmaceutical analysis Author: Petr Šlechta Supervisor: doc. PharmDr. Jan Zitko, Ph.D. Consultant: MSc. Ghada Basem Bouz, Ph.D. Title of diploma thesis: Derivatives combining the fragment of pyrazinamide and 4-aminosalicylic acid as antimycobacterial compounds According to WHO, tuberculosis (TB) is the leading cause of death from a single infectious organism worldwide and the number of cases with drug resistant TB is still increasing, creating the need for new antituberculotics. Therefore, we report design, synthesis and antimicrobial evaluation of a series of hybrid compounds combining different pyrazinamide derivates and p- aminosalicylic acid as potential antituberculotic agents. The compounds were prepared by mixing different pyrazinecarboxylic acids, after activation by 1,1'-carbonyldiimidazole, with p- aminosalicylic acid in dimethylsulfoxide as a solvent. Obtained compounds were in vitro tested for their antimycobacterial activity against M. tuberculosis H37Rv, M. tuberculosis H37Ra and four other mycobacterial strains. Prepared compounds were also in vitro screened for antibacterial, antifungal, and cytotoxic (HepG2) activity. Most compounds showed antimycobacterial activity in range of...
Modulation of pKa of the recognition moiety of azaphthalocyanine sensors
Čermáková, Veronika ; Zimčík, Petr (advisor) ; Zitko, Jan (referee)
Charles University, Faculty of Pharmacy in Hradec Králové Department of Pharmaceutical Chemistry and Pharmaceutical Analysis Candidate: Veronika Čermáková Supervisor: Assoc. Prof. Petr Zimčík, Ph.D. Title of Diploma Thesis: Modulation of pKa of the recognition moiety of azaphtalocyanine sensors Azaphthalocyanines (AzaPc) are macrocyclic compounds containing a large system of conjugated double bonds that enables them to absorb light in the red part of the spectrum that is promising in biological applications. They are characterized by intense red fluorescence as one of the relaxation pathways of the excited state after absorbing a photon. The fluorescence of AzaPc substituted with a phenol moieties on the periphery can be switched ON/OFF depending on the pH of the environment and the pKa of the phenolic group. In basic medium, the molecule occurs as phenolate and undergoes intramolecular charge transfer between the phenolate group (a donor) and the electron- deficient macrocyclic core (an acceptor). As a consequence of this process, the fluorescence is quenched. Switching between ON/OFF states in phenol-substituted AzaPc is dependent on the proton concentration and thus can be utilized in pH sensing. The aim of this work was to synthesize derivatives of phenol-substituted AzaPcs whose pKa is...
Sulfonated azaphthalocyanines - synthesis and evaluation of their photodynamic activity
Jančárová, Alena ; Zimčík, Petr (advisor) ; Doležal, Martin (referee)
Charles University Faculty of Pharmacy in Hradec Králové Department of Pharmaceutical Chemistry and Pharmaceutical Analysis Author: Alena Jančárová Supervisor: doc. PharmDr. Petr Zimčík, Ph.D. Co-supervisor: RNDr. Miloslav Macháček, Ph.D. Title of diploma thesis: Sulfonated azaphthalocyanines - synthesis and evaluation of their photodynamic activity Photodynamic therapy is one of the methods used for destruction of undesirable cells. It combines three essentially nontoxic components: light, oxygen and a photosensitizer. Azaphthalocyanines (AzaPcs) are promising compounds with photosensitizing properties. However, their major disadvantage is their low water solubility and significant aggregation that decreases their photodynamic activity. The aim of this work was to synthesize an anionic derivative of AzaPc substituted with sulfonic groups on periphery characterized by good solubility in water and to evaluate its photodynamic properties. The first step in the synthesis was condensation of diaminomaleonitrile with benzil giving 5,6-diphenylpyrazine-2,3-dicarbonitrile. Subsequently, the cyclotetramerisation with zinc acetate in 2-dimethylaminoethanol as a solvent was performed. The final product was obtained by sulfonation with chlorosulfonic acid followed by hydrolysis with sodium hydrogen carbonate....
Synthesis of BODIPY derivatives for photodynamic therapy
Rydrych, Milan ; Zimčík, Petr (advisor) ; Zitko, Jan (referee)
Charles University Faculty of Pharmacy in Hradec Králové Department of Pharmaceutical Chemistry and Pharmaceutical Analysis Author: Milan Rydrych Supervisor: Prof. PharmDr. Petr Zimčík, PhD. Name of the thesis: Synthesis of BODIPY dyes for photodynamic therapy Borron-dipyromethene dyes (BODIPYs) have been used since the 1990s for their photostability, high absorption coefficients and fluorescence quantum yields. Recently, a modification of the structure using the heavy atom effect was discovered, where high quantum yields of singlet oxygen were also achieved. This fact helped creating a family of compounds with the potential for use in photodynamic therapy (PDT). Previously described BODIPY preparations for PDT are limited by poor solubility in polar environments. This study provides an overview of current synthetic options and basic structure-effect relationships. In the experimental part of the work, three styryl disubstituted substances were prepared with λmax (absorption maximum) at wavelengths in near infrared region with good quantum yields of singlet oxygen and very good photostability. In addition to the target compounds, three 3,5- dialkoxy substituted benzaldehyde derivatives were prepared and characterized as precursors for the final compounds. Finally, the already published synthetic...
Studying the distribution of substituents in derivatives based on hyaluronane
Sedláček, Jakub ; Šatínský, Dalibor (advisor) ; Zimčík, Petr (referee) ; Chmelař, Josef (referee)
Charles University, Faculty of Pharmacy in Hradec Králové Department of Analytical Chemistry Candidate Ing. Jakub Sedláček Supervisor doc. RNDr. Dalibor Šatínský, Ph.D. Title of Doctoral Thesis Studying the distribution of substituents in derivatives based on hyaluronan Derivatives based on hyaluronan have found applications in various areas of medicine. Prepared derivatives are commonly characterized by their molar mass and their degree of substitution, however, such parameters are unable to distinguish among derivatives with different distributions of substituents along the chain, which may exhibit different macroscopic properties. For this reason, methods to determine the distribution of substituents along the chain are needed. The presented thesis deals with the determination of distribution of amino groups in deacetylated hyaluronan. The theoretical part starts with a description of hyaluronan structure and of its derivatives. Next, the application, the preparation, and the characterization of deacetylated hyaluronan are discussed, focusing particularly on its depolymerisation into oligosaccharides using deaminative cleavage or enzymes that degrade hyaluronan. Finally, examples of liquid chromatographic methods used to analyse hyaluronan oligosaccharide are presented. The experimental part...
Novel synthetic approaches toward non-peripherally substituted phthalocyanines
Kočiščáková, Lucia ; Zimčík, Petr (advisor) ; Kučerová, Marta (referee)
Charles University, Faculty of Pharmacy in Hradec Králové Department Department of Pharmaceutical Chemistry and Pharmaceutical Analysis Candidate Lucia Kočiščáková Supervisor Doc. PharmDr. Petr Zimčík, PhD. Title of Thesis Novel Synthetic Approaches Toward Non-Peripherally Substituted Phthalocyanines Phthalocyanines are macrocyclic compounds structurally related to porphyrins, which are used as photosensitizers in photodynamic therapy in the treatment of tumor diseases. The principle of photodynamic therapy is based on activation of photosensitizer by specific wave lenght of light (in the area of visible spectrum), that is absorbed by photosensitizer. The excited photosensitizer releases the absorbed energy by generation of reactive molecule of singlet oxygen that causes damage to cancer cells. In my diploma thesis, we synthesized precursors for phthalocyanines, derivates of phthalonitrile. I was focused on the 3,6-disubstitued phthalonitriles because with the non- peripheral substitution of the final phthalocyanines leads to better, such as significant red shift of the main absorption band. We chose nucleophilic substitution and Buchwald-Hartwig coupling as the main synthetic approaches and we compared different reaction conditions to optimize them.
Synthesis of precursors and studies of "click" azide-alkyne cycloaddition
Ivincová, Jana ; Zimčík, Petr (advisor) ; Roh, Jaroslav (referee)
Charles University in Prague Faculty of Pharmacy in Hradec Králové Department of Pharmaceutical Chemistry and Drug Control Candidate: Jana Ivincová Supervisor: PharmDr. Petr Zimčík, Ph.D. Title of diploma thesis: Synthesis of precursors and studies of "click"azide-alkyne cycloaddition . Photosensitizers are used in photodynamic therapy that is based on a destruction of tumor cells by singlet oxygen. Singlet oxygen is generated during irradiation of photosensitizers. The third generation of the photosensitizers is characterized by high efficiency, optimal spectral properties and particularly by targeted distribution into the tumor cells. This can be achieved by conjugation of phthalocyanine photosensitizer with biomolecules. My thesis concerned with conjugation of suitable phthalocyanine with mestranol using 1,3 azide-alkyne cycloaddition (also called "click chemistry"). Selected photosensitizer with optimal photophysical and photochemical properties was prepared in our department earlier. 1,3 azide-alkyne cycloaddition is CuI catalyzed reaction of azide and terminal alkyne. This reaction is high yielding, selective and easy to perform, without any considerable effects of substituents in proximity of azide or alkyne. Pre-prepared 3-azidopropylamine was linked to the selected phthalocyanine...
Synthesis of azaphthalocyanines bearing one 2,6-di(tert-butyl)phenol substituent
Lásková, Miroslava ; Zimčík, Petr (advisor) ; Kučerová, Marta (referee)
Charles University in Prague, Faculty of Pharmacy in Hradec Králové Department Department of Pharmaceutical Chemistry and Drug Control Candidate Miroslava Lásková Supervisor Doc. PharmDr. Petr Zimčík, Ph.D. Title of Thesis Synthesis of azaphthalocyanines bearing one 2,6-di(tert-butyl)phenol substituent In this work, azaphthalocyanines (AzaPc) bearing one 2,6-di(tert-butyl)phenol substituent were synthesized. Phenolic OH in this moiety is a weak donor for intramolecular charge transfer (ICT). However, this group can be ionized in basic media and the resulting phenolate anion is very strong donor. This was expected to cause ICT and quench fluorescence of this compound. The precursors for AzaPcs are substituted pyrazine-2,3-dicarbonitriles. They were prepared via one- step reaction of 5,6-dichloropyrazine-2,3-dicarbonitrile with 2-methylpropane-2-thiolate, respectively octanethiolate or via two-step reaction of 5,6-dichloropyrazine-2,3-dicarbonitrile with 2,6-di(tert- butyl)phenolate followed by nucleophilic substitution by 2-methylpropane-2-thiolate, respectively octanethiolate. Another precursor was prepared via reaction of glyoxylic acid with diaminomaleonitrile followed by chlorination with phosphoryl chloride and by subsequent nucleophilic substitution by 2,6- di(tert-butyl)phenolate. Resulting...

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