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New pharmacological interventions influencing food intake regulation
Špolcová, Andrea ; Čabala, Radomír (advisor) ; Podlipná, Radka (referee)
NEW PHARMACOLOGICAL INTERVENTIONS INFLUENCING FOOD INTAKE REGULATION Author: Bc. Andrea Špolcová ABSTRACT Prolactin-releasing peptide (PrRP) identified as an endogenous ligand of the orphan receptor GPR10 was originally found to stimulate the secretion of prolactin (PRL) both in vitro and in vivo. PrRP-mediated PRL secretion was later questioned and is not currently considered to be the primary function of PrRP. The fact that both PrRP and GPR10 knock-out mice are hyperphagic and develop late-onset obesity proves the unique anorexigenic properties of PrRP. Designing and evaluation of PrRP analog(s) with selective anorexigenic properties and searching for PrRP antagonists would contribute to finding the mechanism and possible treatment of obesity and metabolic syndrome. In our recent published study (Maixnerová et al., Peptides (2011)), the PrRP receptor was immunodetected and characterized by saturation binding in three rodent tumor pituitary cell lines. Two naturally occurring analogs, PrRP31 and PrRP20, showed comparable potency in binding, cell signaling and prolactin release in pituitary RC-4B/C cells, as well as caused food intake decrease after intracerebroventricular administration in fasted mice. In the present study, analogs of PrRP20 with C-terminal Phe amide derivatives with modified aromatic...
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Analysis and characterization of antimicrobial peptides by capillary electrophoresis
Hlavsová, Tereza ; Coufal, Pavel (advisor) ; Čabala, Radomír (referee)
Capillary zone electrophoresis (CZE) with UV-photometric detection at 206 nm was used for the determination of degree of chemical purity, limit of detection and limit of quantitation of antimicrobial cationic peptide halictine and its 25 analogs. Halictine and its analogs were chracterized by their effective electrophoretic mobilities corrected to reference temperature 25 řC in several acidic background electrolytes. Separations of mixtures of structurally related analogs of halictine were performed by capillary zone electrophoresis (CZE) and micellar electrokinetic chromatography (MEKC). The highest values of separation effeciency, up to 2.36∙105 theoretical plates per meter, were achieved by CZE in the background elektrolyte containing 30 mM phosphoric acid, 25 mM Tris and additive of cationic surfactant 0.4 mM didodecyldimethylammonium bromide (DDAB), pH 2.85. The highest values of resolution of CZE separations of peptides were found in background electrolyte composed of 30 mM phosphoric acid, 25 mM Tris, 0.4 mM DDAB and 0.1 % (m/v) hydroxyethylcellulose, pH 2.84.
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Application of monosubstituted cyclodextrins in chiral separation of omeprazole by capillary electrophoresis
Dvořák, Aleš ; Coufal, Pavel (referee) ; Čabala, Radomír (advisor)
Chiral separation of omeprazole was the subject of this work. Five diferent monosubstituted derivatives of α- and β-cyclodextrins, two of them cationic and three anionics, were used as chiral selectors in various buffers of different pH. The influence of CD and buffer concentrations on chiral separation was studied. Voltage of 25 kV, UV detection in the range from 202 to 303 nm and constant temperature of 20 řC was used for all measurements. Concentration of CDs between 0 and 7 mmol.l-1 was used. Fused silica capillary of 50 µm ID and 375 µm OD, 48,5 cm total and 40 cm effective lenght was used as separation capillary. Dimethylformamide was used in stock solution of omeprazole as solvent, and was simultaneously applied as EOF marker. Succesfull chiral separation of omeprazole was achieved under the application of 2'-O-carboxymethyl-β-cyclodextrin (2'-CM-β-CD) and mono-6-deoxy-6-N,N,N',N',N'-pentamethylethylendiammonio- cyclomaltoheptaose dichloride (PEMEDA-β-CD) where the resolution of 1,42 (pH = 5,1) and 4,29 (pH = 11,1) was measured, respectively.
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Analysis, characterization and separation of 2,6-diaminopimelic acid derivatives by capillary zone electrophoresis and micellar electrokinetic chromatography
Vítovcová, Miloslava ; Čabala, Radomír (referee) ; Coufal, Pavel (advisor)
In this work, capillary zone electrophoresis (CZE) and micellar electrokinetic chromatography (MEKC) with UV-photometric detection were used for the determination of degree of chemical purity, limit of detection (LOD) and limit of quantitation (LOQ) of N-acyl derivatives of 2,6-diaminopimelic acid (DAP). The characterization of DAP derivatives was performed by determination of their effective electroforetic mobilities in several background electrolytes in acidic and alkalic pH range. The mobilities were corrected to reference temperature 25 řC. Separation of the mixture of DAP derivatives were achieved by MEKC in acid background elektrolyte (500 mmol·dm-3 acetic acid, pH 2.54) using anionic surfactant 60 mmol·dm-3 sodium dodecylsulfate (SDS) as a constituent of the micellar pseudostationary phase. Subject words: analytical chemistry, separation methods, capillary electromigration methods, derivatives of amino acids Key words: capillary zone electrophoresis, micellar electrokinetic chromatography, derivatives of 2,6-diaminopimelic acid
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Pharmaceutical application of high performance ion chromatography in analysis of organic anions and cations
Čujová, Sabína ; Čabala, Radomír (referee) ; Pacáková, Věra (advisor)
The thesis is focused on application of ion chromatography in pharmaceutical analyses of organic ions. Ion chromatography is increasingly used in the field of pharmaceutical analysis. This includes the analysis of impurities and metabolites. In the first part of this thesis, ion chromatography is compared with common separation techniques used in pharmacy, such as gas chromatography and high performance liquid chromatography. In the second part development and validation of methods of ion chromatography for purity evaluation and quality control of active pharmaceutical substances Rivastigmine hemitartrate and Pramipexole hydrochloride were carried out. Key words: ion chromatography, reversed-phase chromatography, ion-pair chromatography, ion-exclusion chromatography, ion-exchange chromatography, GC, HPLC
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