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HPLC Analysis of Anthelmintics Using Core-shell Columns
Marková, Jitka ; Kubíček, Vladimír (advisor) ; Lázníčková, Alice (referee)
Charles University in Prague Faculty of Pharmacy in Hradec Králové Department of Biophysics and Physical Chemistry Candidate: Jitka Marková Consultant: Ing. Vladimír Kubíček, CSc. Title of Thesis: HPLC Analysis of Anthelmintics Using Core-shell Columns This diploma thesis deals with HPLC analysis of three anthelmintics included into AAD group (i. e. amino-acetonitrile derivatives). Suitable separation conditions were studied using three core-shell columns (i. e. Ascentis Express RP - Amide, Ascentis Express F5 and Kinetex PFP). Finally, an efficiency of two preextraction methods (SPE, LLE) was tested. The obtained results show the Ascentis Express RP-Amide column to be the suitable choice for the required purpose. The proposed mobile phases are MS compatible. SPE column STRATA X, exhibiting very high recoveries, is the best choice for SPE. The LLE recovery ratio can be taken as satisfactory.
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Comparison of Photophysical Properties of Different Types of Azaphthalocyanines
Reimerová, Petra ; Nováková, Veronika (advisor) ; Kubíček, Vladimír (referee)
Charles Univerzity in Prague, Faculty of Pharmacy in Hradec Králové Department: Department of Biophysics and Physical Chemistry Candidate: Petra Reimerová Supervisor: PharmDr. Veronika Nováková, Ph.D. Title of Thesis: Comparison of Photophysical Properties of Different Types of Azaphthalocyanines Phthalocyanines and their aza-analogues azaphthalocyanines are organic dyes with planar macrocyclic structure and metal cation coordinated in the center. They can be used in many applications - for example as sensors, dyes or sensitizers in photodynamic therapy. The aim of this study was to compare photophysical properties (absorption, fluorescence, singlet oxygen production), solubility, aggregation and acid-base properties of several molecules 1-7 that differ in the type of macrocyclic core (see Figure below). The strength of absorption expressed as an extinction coefficient increased with the bathochromic shift of the Q-band. The position of the Q band depended on the number of conjugated double bonds and on the position of the peripheral substituents. Isosteric exchange of benzene rings to pyrazine rings shifted Q-band to shorter wavelength. Quantum yields of singlet oxygen (Φ∆) and quantum yields of fluorescence (ΦF) were determined in pyridine and THF by comparative method with ZnPc as a reference....
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Use of SPE in HPLC Analysis II
Soukupová, Marie ; Kubíček, Vladimír (advisor) ; Link, Marek (referee)
Souhrn Tato diplomové práce byla věnována optimalizaci metody předseparace amlodipinu z biologických vzorků pomocí extrakce na tuhých fázích před samotnou chromatografickou analýzu. Celkem byly otestovány tři typy tuhých fází různé polarity vhodných pro extrakci léčiva, řada elučních činidel a byly modifikovány podmínky extrakce. Nejlepších výsledků bylo dosaženo s tuhými fázemi s navázanými kyanopropylovými skupinami a činidlem o složení amoniak 25% : acetonitril 1:3 (v/v). Jako vnitřní standard pro následné chromatografické analýzy amlodipinu s fluorimetrickou detekcí byl navržen pyren, možnost jeho použití byla potvrzena výsledky fluorimetrického stanovení. Metoda optimalizovaná pokusy s modelovými vzorky léčiva rozpuštěného v pufru byla vyzkoušena při práci s reálným biologickým materiálem.
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Study of radiolabeling of chemically modified bombesines
Saranti, Evangelia ; Lázníčková, Alice (advisor) ; Kubíček, Vladimír (referee)
STUDY OF RADIOLABELING OF CHEMICALLY MODIFIED BOMBESINES Diploma Thesis Evangelia Saranti Charles University in Prague, Faculty of Pharmacy in Hradec Kralove Department of Biophysics and Physical Chemistry The aim of this thesis was to study the radiolabeling of new perspective receptor-specific peptide DOTA-Lys3-bombesin with therapeutic radionuclide Lu-177 and to determine the stability of the labeled product. We have found the optimum conditions for radiolabeling of selected peptide: pH 5.0 and incubated at 42ř C for 35-40 minutes. Under these conditions sufficient radiochemical purity for biological testing of substance was achieved (higher than 97%). We tested the stability of the radiolabeled product when it was stored at 4ř C, and both in the environment by an order of magnitude higher concentration of competing ligand EDTA or DTPA. Stored in the refrigerator peptide was stable for at least four hours after preparation, study of stability in an environment of competing ligands showed good stability of the DOTA-complex with lutetium-177. Comparison of methods for determination of radiochemical purity of the radiolabeled peptide showed greater reliability of HPLC analysis compared to thin-layer chromatography.
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Determination of Potential Drugs in Biological Matrices
Suchardová, Jana ; Kubíček, Vladimír (advisor) ; Lázníčková, Alice (referee)
Charles University of Prague Fakulty of Pharmacy in Hradec Králové Department of Biophysics and Physical Chemistry Candidate: Jana Suchardová Consultant: Ing. Vladimír Kubíček, CSc. The aim of this diploma thesis was to find suitable conditions for HPLC determination of VN 014 in biological matrices. Experiments were carried out on four core-shell columns (Ascentis® Express F5, Ascentis® Express C18, Ascentis® Express Phenyl-Hexyl, Ascentis® Express RP-Amide) with different mobile phases. In this thesis two extraction methods were also tested - solid phase extraction and liquid-liquid extraction. The best results were achieved on Ascentis® Express RP-Amide column with the mobile phase composed of 0.03 mol/l formic acid and methanol. LLE method was chosen for the sample preparation. Key words: HPLC, core-shell columns, SPE, LLE, RP-Amide
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Interaction of Tensides and Organic Dyes in Solutions II
Bukatová, Helena ; Kubíček, Vladimír (advisor) ; Lázníčková, Alice (referee)
Charles University in Prague Faculty of Pharmacy in Hradec Králové Department of Biophysics and Physical Chemistry Candidate: Helena Bukatová Supervisor: Ing. Vladimír Kubíček, CSc. Title of diploma thesis: Interaction of Tensides and Organic Dyes in Solutions II This diploma work is devoted to examination of the aqueous solutions of surfactants and organic dyes in the solution of Britton-Robinson buffer by two spectral methods: UV-VIS absorption spectrophotometry and fluorescence spectroscopy. There are two different dye-surfactant systems investigated: neutral red with sodium lauryl sulfate and phenol red with hexadecyl-trimethyl-ammonium bromide. The possible interactions were observed in the several surfactant concentration levels of the solutions with increased dye concentration. The task of my work was investigation of changes in dye spectra as a consequence of the dye-surfactant interaction and determination of the possible origin of the spectra changes. The results showed that absorption spectra of solutions containing neutral red itself differ sharply from those taken for solutions of neutral red and the tenside. The different character of the spectra is observable from the concentration of the tenside 6∙10-5 mol/l. Two types of dye-tenside associate are probably formed. The associate...
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Determination of Lipophilicity of Drugs by HPLC
Pleváková, Magdaléna ; Kubíček, Vladimír (advisor) ; Nováková, Veronika (referee)
3 ABSTRACT Charles University in Prague, Faculty of Pharmacy in Hradec Králové Department of biophysics and physical chemistry Author: Magdaléna Pleváková Supervisor: Ing. Vladimír Kubíček, CSc. Thesis title: Determination of Lipophilicity of Drugs by HPLC In this thesis a RP-HPLC method for fast and reliable determination of lipophilicity was proposed and tested. Stationary phase was selected by using hydrophobic substraction model. Capacity factors of the chosen substances were initially measured on Zorbax ECLIPSE XDB C18 250x4,6 mm, 5µm column, which exhibits almost identical retention characteristics as the column used for this purpose until now. Then the capacity factors of the same substances were determined by using Zorbax ECLIPSE XDB-C18 50x4,6 mm, 1,8µm column that was selected to reduce retention times significantly. A group of newly synthesised drugs based on structure of pyrazine served as samples for the measurement. The reproducibility of the capacity factor values determined using both columns was compared and the independence of the capacity factor on the mobile phase flow was confirmed. The capacity factors of two homologous series and a group of benzimidazols were consequently determined on Zorbax ECLIPSE XDB-C18 50x4,6 mm, 1,8µm column using various compositions of mobile phases. Several...
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Synthesis of Trichloroacetyl Esters of Aldols
Žáková, Lenka ; Kubíček, Vladimír (advisor) ; Jezberová, Michaela (referee)
This diploma thesis describes synthesis of trichloroacetyl esters of aldols which were obtained by a reaction of trichloroacetic acid with formaldehyde and another comercial aldehyde. Used were hydratopaldehyde, isobutyraldehyde, 2-methylpentanal, 2-ethylhexanal and 2-ethylbutanal. Some of these esters were described in the literature but only in part, several of them are new compounds. Excellent yields and clean products prove that the applied method is a good way to achieve these compounds that can be easily used for further processes.
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