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The uset of HPLC in the field of chiral separations VIII.
Šlapáková, Tereza ; Horáček, Ondřej (advisor) ; Lochman, Lukáš (referee)
Charles University Faculty of Pharmacy in Hradci Králové Department: Department of Pharmaceutical Chemistry and Pharmaceutical Analysis Student: Bc. Tereza Šlapáková Supervisor: RNDr. Ondřej Horáček, Ph.D. Consultant: doc. PharmDr. Radim Kučera, Ph.D. Title of thesis: The uset of HPLC in the field of chiral separations VIII. Carboranes are highly stable, hydrophobic, inorganic compounds that are based on an icosahedral structure composed of boron atoms. Some carborane representatives are chiral, which is mainly due to asymmetric substitution. The establishment of reliable and rapid methods to enable the separation of the enantiomers is necessary, which is important for their future use in practice. The high-performance liquid chromatography method is advantageous for practical application as it is widely used, robust, and applicable to a large range of fields. The aim of this work was to test the behavior of chiral carboranes on polysaccharide columns in HPLC. First, screening was performed by gradient method using six chiral polysaccharide-based stationary phases, the component A of the mobile phase was 50 mmol/l NaClO4, and the component B was ACN or MeOH. Subsequently, the method was converted to isocratic elution. The purpose of this study was to optimize the conditions to create a database of...
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Chiral separation of boron cluster compounds II.
Zámyslická, Yvette ; Kučera, Radim (advisor) ; Kastner, Petr (referee)
Charles University Faculty of Pharmacy in Hradec Králové Department: Department of Pharmaceutical Chemistry and Pharmaceutical Analysis Candidate: Yvette Zámyslická Supervisor: doc. PharmDr. Radim Kučera, Ph.D. Consultant: RNDr. Ondřej Horáček, Ph.D. Title od Thesis: Chiral separations of borane cluster compounds II. This diploma thesis focuses on screening and optimisation of chiral separations of borane cluster compounds. Approximately more than half of the currently used medications are chiral compounds whose isomers can differ in biological activity. Borane cluster compounds, some of which are chiral, represent a significant substance category due to their chiral aspects which offer new possibilities in synthesis and modification of drug structures. The aim of this diploma thesis is to propose an optimised approach for the analysis of borane cluster compounds and achieve a successful separation of enantiomers. The theoretical part of the thesis focuses on the analysis of the basic principles of high-performance liquid chromatography, the importance of optical isomerism, the basic principles of chiral separations and introduction of borane clusters together with the possibilities of their usege in modern pharmacotherapy. The practical part of the thesis focuses on experimental assessment of...
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Preparation of new chiral phases for HPLC anchored to silica gel using electrostatic interactions
Tomanová, Adéla ; Jindřich, Jindřich (advisor) ; Smrček, Stanislav (referee)
The focus of this thesis is the synthesis of chiral modifiers for silica gel based on amylose modified with dimethyl or dichlorophenyl isocyanates and positively charged anchors, which will allow strong ionic binding to silica gel. The stability of the stationary phases thus prepared is then studied by liquid chromatography as well as the ability to separate selected enantiomers. Two chiral silica gel modifiers were prepared in which the amylose contained dimethyl phenyl carbamate (DMFKA) or dichlorophenyl carbamate (DCFKA) groups in addition to the covalently bonded anchor. The results of elemental analysis showed incomplete modification of the hydroxyl groups of the second modifier, DCFKA, which also corresponded to the poor chromatographic results obtained on columns packed with this phase. Enantioselective separations of α-(1-naphthyl)benzylamine, fenamiphos and a number of chiral adamantane derivatives were achieved on columns packed with DMFKA phase. The possibility of modifying silica gel in an already packed HPLC column with a modifier from solution was also demonstrated by pumping this solution through a silica gel packed column and subsequent washing into the mobile phase. Keywords: chiral separation, electrostatic interaction, HPLC
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Chirality and its importance in environmental organic analysis
Svobodová, Dagmar ; Friedl, Zdeněk (referee) ; Čáslavský, Josef (advisor)
This bachelor thesis is elaborated as literature search focused on the characterization of chirality and its importance for the environment. This work also gives review of the analytical methods and procedures aplicable for the chiral analysis of the organic pollutants. Obtained information showed that the importance of the chirality in the environmental chemistry is great. Individual enantiomers exhibit different toxicity and biological activity in the environment and therefore their monitoring by chiral analytical methods is essential.
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Evaluation of applicability of indirect photometric detection for chiral separations of selected carboxylic acids in dairy products
Dvořák, Miloš ; Zemanová, Jana (referee) ; Vespalcová, Milena (advisor)
In this diploma work is check possibility application indirect photometric detection for enantiomers separation lactic acids and beta-hydroxybutyric acid with capillary electrophoresis. As chiral selector is used vankomycin. Verifyed his ability partial separation lactic acid on antipode with using picric acid as vizualition anion in background electrolyte. Used was coated capillary. Application indirect photometric detection succeed. Chiral separation beta-hydroxybutyric acid wasn't successful. Hip roll by selection fit vizualization anions for purposes indirect photometric detection. Are measured their electrophoretic and spectrophotometric characteristics, for inquest compatibility use in capillary electrophoresis in relation to indirect photometric detection. From timed datums were to be you - nap optimal vizualizatin anions for others experimentation. According to ascertained and measured feature reflect be optimal eosine soluble in alcohol and bromophenol blue.
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The uset of HPLC in the field of chiral separations VII.
Štilcová, Kristýna ; Kučera, Radim (advisor) ; Pilařová, Pavla (referee)
Charles University Faculty of Pharmacy in Hradec Králové Department: Department of Pharmaceutical Chemistry and Pharmaceutical Analysis Student: Kristýna Štilcová Supervisor: doc. PharmDr. Radim Kučera, Ph.D. Consultant: Mgr. Ondřej Horáček Title of Thesis: The employment of HPLC in the field of chiral separations VII. Boron clusters are inorganic, synthetically prepared, three-dimensional, cage-like structures. Boron cluster compounds which are made only of boron and hydrogen atoms are completely symmetrical. Their symmetry can be disrupted by endo- or exoskeletal substitution resulting in chiral compounds. Carboranes, subgroup of the boron cluster compounds, contain at least one carbon atom in their structure and usually include exoskeletal substitution. Therefore, the metallacarboranes containing cobalt bis(dicarbollides) and 7,8-dicarba-nido-undecaborates that have been studied can be found among these chiral structures. Thanks to the specific properties such as high lipophilicity, metabolic stability and delocalized negative charge, the studied compounds can be used as isosteric substitution of phenyl ring in pharmacophores. Due to the growing interest in cobalt bis(dicarbollides) and 7,8-dicarba-nido-undecaborates and the importance of chirality in pharmacy, suitable conditions for chiral...
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The uset of HPLC in the field of chiral separations VII.
Štilcová, Kristýna ; Kučera, Radim (advisor) ; Pilařová, Pavla (referee)
Charles University Faculty of Pharmacy in Hradec Králové Department: Department of Pharmaceutical Chemistry and Pharmaceutical Analysis Student: Kristýna Štilcová Supervisor: doc. PharmDr. Radim Kučera, Ph.D. Consultant: Mgr. Ondřej Horáček Title of Thesis: The employment of HPLC in the field of chiral separations VII. Boron clusters are inorganic, synthetically prepared, three-dimensional, cage-like structures. Boron cluster compounds which are made only of boron and hydrogen atoms are completely symmetrical. Their symmetry can be disrupted by endo- or exoskeletal substitution resulting in chiral compounds. Carboranes, subgroup of the boron cluster compounds, contain at least one carbon atom in their structure and usually include exoskeletal substitution. Therefore, the metallacarboranes containing cobalt bis(dicarbollides) and 7,8-dicarba-nido-undecaborates that have been studied can be found among these chiral structures. Thanks to the specific properties such as high lipophilicity, metabolic stability and delocalized negative charge, the studied compounds can be used as isosteric substitution of phenyl ring in pharmacophores. Due to the growing interest in cobalt bis(dicarbollides) and 7,8-dicarba-nido-undecaborates and the importance of chirality in pharmacy, suitable conditions for chiral...
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Chiral separation of boron cluster compounds
Linková, Kristýna ; Kučera, Radim (advisor) ; Lochman, Lukáš (referee)
Charles University Faculty of Pharmacy in Hradec Králové Department of Pharmaceutical Chemistry and Pharmaceutical Analysis Candidate: Kristýna Linková Supervisor: doc. PharmDr. Radim Kučera, Ph.D. Consultant: Mgr. Ondřej Horáček Title of thesis: Chiral separation of boron cluster compounds The boron atom has the ability to form electro-deficientient bonds, when only two electrons participate in the three bonds. Significant delocalization of electrons over the three- center bond is responsible for the formation of three-dimensional clusters. Boron cluster compounds have an abiotic character. They are characterized by their specific properties, such as thermal and metabolic stability, high lipophilicity and delocalized negative charge. These compounds are investigated as isosteric to phenyl group in the field of medicinal chemistry. They have anti-cancer activity, the ability to inhibit HIV-proteases and anti-rheumatoid activity. Furthermore, boron cluster compounds have been used in neutron capture therapy in the treatment of cancer. Some boron cluster compounds studied as new potential drugs are chiral, therefore it is necessary to get enantiomerically pure substances to further expand their use in pharmacy and medicine. The recent investigations in our research group have been focused on the...
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Study of peptide digestion kinetics by trypsin and chiral separations of biologically active compounds by HPLC
Šlechtová, Tereza ; Tesařová, Eva (advisor) ; Čabala, Radomír (referee) ; Mikšík, Ivan (referee)
This dissertation thesis composes of two parts; the first part focus on the characterization of trypsin, enzyme frequently used in proteomic research for the investigation and identification of protein sequences, and its peptide digestion kinetics. The second part is aimed to the enantioseparations of biologically active compounds. First part of this project focus on tryptic digestion of synthetic peptides and the development of HPLC method for the identification of synthetic peptides and their fragments. Using the in-solution digestion and HPLC method, relative kinetic constants were determined for problematic sequences. Amino acids responsible for the decrease in trypsin catalytic activity and their location towards the cleavage site were studied. Certain slight exopeptidase activity of trypsin was noted, especially at the end of peptide chain. Furthermore, three columns with immobilized trypsin used in HPLC were compared concerning their catalytic activity. The immobilization of enzymes on solid support is used to elevate the amount of enzyme present during digestion and to assure better repeatability and reproducibility of obtained results. Activity of a new trypsin column synthesized at the University of North Carolina at Chapel Hill was compared to two commercially available trypsin columns....
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Determination of pesticides enantiomers in water
Šlechtová, Tereza ; Tesařová, Eva (advisor) ; Lokajová, Jana (referee)
This Barchelor's project deals with chiral herbicide mecoprop and its determination by high-performance liquid chromatography method with teicoplanin based chiral stationary phase. The teoretical part focus on basic facts conserning chirality, chiral pesticides and problems related to their usage and effects to the enviroment. It also involves the ways of their determination by the above mentioned method and gives several examples of previous separations. The experimental part is based on method optimalization and determination of changes in mecoprop enantiomeric ratio in various water samples during different storage conditions.
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