|
|
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.
|
|
|
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.
|
|
|
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...
|
|
|
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...
|
|
|
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...
|
|
|
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....
|
|
|
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.
|
|
|
Selectively substituted cyclodextrins for analytical and pharmaceutical applications
Benkovics, Gábor ; Jindřich, Jindřich (advisor) ; Lhoták, Pavel (referee) ; Šindelář, Vladimír (referee)
3 Selectively substituted cyclodextrins for analytical and pharmaceutical applications Abstract This thesis is focused on the selective modification of cyclodextrins, and its primary aim is the preparation and characterization of mono- and persubstituted derivatives of cyclodextrins in a regioselective and straightforward manner. The work is divided into two main parts describing synthetic strategies and applications of modified cyclodextrins with one or several substituents, respectively. The first section deals with the introduction of a single chromophoric moiety on the cyclodextrin scaffold such as cinnamyl, rhodaminyl, fluoresceinyl and eosinyl groups. The complete set of monocinnamyl-α-cyclodextrin regioisomers has been prepared by direct alkylation, and the self-assembling properties of the corresponding regioisomers were thoroughly investigated by dynamic light scattering and NMR experiments. These investigations revealed that the different isomers (mono-6-O-, mono-2-O- and mono-3-O- cinnamyl-α-cyclodextrin) form distinct supramolecular species through intermolecular association. A fast method for the unambiguous identification of the pure regioisomers has also been developed based on a series of 2D NMR measurements. Xanthene-modified β-cyclodextrins, other representatives of monosubstituted...
|
|
|
Use of chiral stationary phases based on teicoplanin and teicoplanin aglycone for enantioseparation of FMOC-derivatized amino acids.
Repko, Pavel ; Bosáková, Zuzana (advisor) ; Tesařová, Eva (referee)
In this work, an enantioselective HPLC method with UV and fluorimetric detection was developed and subsequently optimized for chiral separation of four aminoacids (D/L-alanine, D/L-valine, D/L-leucine, D/L-isoleucine) in native and particularly in derivatized form with an emphasis on enantioseparation of D-analogues. Retention and enantioseparation behavior of studied analytes was investigated on three chiral stationary phases based on teicoplanin (Chirobiotic T, Chirobiotic T2) and teicoplanin aglycone (Chirobiotic TAG). At the Chirobiotic T column, enantioseparations of underivatized aminoacids were performed with UV detection at 205 nm in the mobile phases methanol/water with different volume ratios. Baseline separation of L- and D-forms was achieved, however, the sensitivity of detection was very low. In order to increase detection sensitivity, derivatization of aminoacids was performed using 9-fluorenylmethyl chloroformate (FMOC-Cl) and the derivatization procedure was monitored on Chirobiotic T column with fluorimetric detection (λEx = 254 nm, λEm = 314 nm) in a buffered mobile phase methanol/0.5% TEAA buffer, pH 6.0 40/60 (v/v). In terms of derivatization, volume ratio D/L-aminoacid/derivatization agent 1/1 with ten times higher concentration of derivatization agent was found to be the most suitable....
|
|
|
Chiral HPLC separation of newly synthesized amino acids
Kučerová, Gabriela ; Kalíková, Květa (advisor) ; Riesová, Martina (referee)
The aim of this work was to develop and to optimize HPLC method for enantioseparation of newly synthesized derivatives of amino acids. The set of these analytes contained four N- blocked derivatives of D,L-Phenylalanine, three N-unblocked derivatives of D,L- Phenylalanine, , one methylated derivative of D,L-Tyrosine and D,L-Tyrosine. Two separation modes i.e. reversed phase and polar-organic modes and two columns i.e. Chirobiotic® T and Chirobiotic® T2 were used. Chiral stationary phases of these columns were composed of macrocyclic antibiotic teicoplanin coated on silica gel support. As mobile phases in revesed phase mode, methanol and acetate buffer were used with Chirobiotic® T column. The most suitable concentration were 20 mM and the most suitable pH value were 4.00. Under the above mentioned conditions eight analytes of ten were separated and the optimal conditions were found. Polar-organic mode and Chirobiotic® T column were suitable only for enantioseparation of three N-blocked derivatives of D,L- Phenylalanine. Mobile phases were composed of methanol with small additions of triethylamine and acetic acid. Chirobiotic® T2 column in reversed phase mode was not suitable for tested set of analytes. Only partial separation of D,L-Tyrosine derivative and one N-unblocked D,L-Phenylalanine...
|
guest ::
