National Repository of Grey Literature 18 records found  1 - 10next  jump to record: Search took 0.00 seconds. 
Efficiency of Water Treatment Processes Using Activated Carbon
Hladíková, Lucie ; Kolesíková, Lucie (referee) ; Kučera, Tomáš (advisor)
The subject of the thesis is the issue of pesticides in the environment and the possibility of their removal through activated carbon. The thesis is divided into two parts, the search part and the practical part. The research part is focused on description of activated carbon. It also deals with the distribution of pesticides and their degradation in the environment. In the practical part, a laboratory experiment was carried out to determine the effectiveness of removing pesticides and metabolites from the test water on two types of activated carbon.
Biotransformation of ferulic acid to sensory active compounds
Opial, Tomáš ; Pernicová, Iva (referee) ; Obruča, Stanislav (advisor)
The bachelor thesis deals with the biotransformation of ferulic acid to sensory active substances. The experiment was based on monitoring the biotransformation potential of selected microorganisms by high performance liquid chromatography (HPLC) method while the cultivation was performed in two parallel runs and samples with added ferulic acid were divided into 24-hour effect and 48-hour effect of ferulic acid on bacterial cultures. Thermophilic bacteria and halophilic bacterium Halomonas neptunia have been found to be the most suitable candidates for the biotransformation of ferulic acid to sensory active substances. In both samples of Schlegelella thermodepolymerans (DSM 15344 and DSM 15264) was formed 33 mg/l and 76 mg/l of vanillic acid and 81 mg/l and 71 mg/l of 4-vinylguaiacol after 24 hours of ferulic acid effect. In a sample with T. taiwanensis was formed 61 mg/l of vanillic acid and 32 mg/l of 4-vinylguaiacol after 48 hours of ferulic acid effect, and in a sample of R. xylanophilus was formed 56 mg/l of 4-vinylguaiacol. In the sample with H. neptunia after 24 hours of ferulic acid effect was formed 296 mg/l of vanillic acid, which was up to 59% of the conversion of the added ferulic acid and in a sample with H. organivorans after 24 hours of ferulic acid effect was formed 71 mg/l of vanillic acid. However, after 48 hours of ferulic acid effect, vanillic acid degraded. In addition to screening of biotransformation potential, the sequence of bacterial enzymes, involved in biotransformation, was also compared with protein sequences in the database using the BLAST search tool. The presence of genes encoding enzymes involved in biotransformation has been demonstrated for almost all used microorganisms except H. neptunia, for which no gene has been identified. The highest number of genes present in bacteria was with the enzymes feruloyl-CoA synthetase, enoyl-CoA hydratase/isomerase, acetoacetyl-CoA thiolase and vanillin dehydrogenase.
Vliv abiotických faktorů (teploty) na vybrané druhy zelených mikrořas
Ston, Michal
Microalgae as a unicellular organism are part of huge variety of ecosystems, and therefore, are susceptible to environment changes. They have developed mechanisms helping them to adapt to those changes. Although some changes can have negative effect on cell life. Even though, many algae have adapted to extreme conditions, the main problem is climate change and sudden temperature changes that lead to cell damage of microalgae. The main objective of the present master's theses was to compare and evaluate effect of increased temperature on different types of microalgae. The results suggest that effect of temperature of 40 °C had a different effects in Chlorella sorokiniana and Scenedesmus obliquus which was found using spectrophotometer analysis of photosynthetic pigments, secondary metabolites, and antioxidant capacity. The results showed that Chlorella sorokiniana reacted positively to higher temperature of 40 °C by increasing production of those compound, respect to the control groups at 23 °C (p ≤0,01). Scenedesmus obliqus mainly answered by lowering production of compounds, except of chlorophyll b that showed increase in production. In all studied parameters, statistically significant differences were observed (p ≤0,01) between Chlorella sorokiniana and Scenedesmus obliquus at 40 °C. Specifically, Chlorella sorokiniana showed better adaptive response to increased temperature in all investigated parameters.
Funkční profilování komponentů komplexu transkripčních koaktivátorů SAGA v Arabidopsis
Sokolov, Rodion
Regulation of gene expression can be carried out by various mechanisms, one of them is enzyme-mediated modification of histones. Such enzymes often form large multi-subunit complexes to facilitate their enzymatic activity and substrate specificity. The Spt-Ada-Gcn5 acetyltransferase (SAGA) complex is a complex of transcriptional coactivators highly conserved between plants and yeast. In plants, SAGA can regulate gene expression through histone acetylation and deubiquitination. PHYTOCHROME-DEPENDENT LATE-FLOWERING (PHL)/SPT20 is a subunit of the structural module SAGA, that interacts with phytochrome B and thus regulates flowering, but at the same time its expression affects plant response to drought and nitrogen deficiency. In the experimental part of this work, the effect of PHL on resistance to other abiotic stresses, such as oxidative and osmotic stress was investigated. The response of plants defective in the gene encoding PHL to the given stresses was shown to be dependent on the photoperiod, whereby the impact of oxidative stress was more pronounced when grown under long-day conditions. On the contrary, plants were more sensitive to osmotic stress under short-day conditions. In this study, the metabolites present in the phl mutant line at a different concentration than in the standard plants were identified and may thus be responsible for the different response of this line to stress.
Electrochemical Techniques in Monitoring of Nervous System Drugs
Choińska-Mlynarczyk, Marta ; Hrdlička, Vojtěch ; Skopalová, J. ; Šelešovská, R. ; Kolivoška, Viliam ; Navrátil, Tomáš
Drugs of the nervous system (ATC group N) belong generally to the most commonly (mis)used substances worldwide. Their determination and monitoring of these drugs and their metabolites in various body fluids or environmental matrices represent a challenge for analytical chemists. Our research is focused on the application of electrochemical methods in the monitoring of the most frequently prescribed and the newly introduced nervous system drugs of precisely specified structures and/or of defined properties. For toxicological and pharmacokinetic reasons, emphasis has been placed on investigating the reaction mechanisms of their metabolite formation. New or alternative to commonly used electroanalytical methods applicable for monitoring and characterization of target compounds in their pure state, in body fluids, wastewaters, and other environmental matrices, has been developed. To improve the chemometric parameters and sensing characteristics, attention was paid to the construction of new electrochemical sensors, detectors (e.g. screen-printed, 3D printed), or cells, based on (modified/unmodified) traditional or nontraditional materials, preferably usable at the point-of-care.
LC-MS/MS study of phase one in vitro biotransformation of potential drugs against Alzheimer's disease
Kuřátková, Aneta ; Kučera, Radim (advisor) ; Váňová, Nela (referee)
No treatment that would completely stop the progression of Alzheimer's disease has not been found yet. Recently used tacrine showed good results in the treatment of Alzheimer's disease, however long-term use led to chronic hepatotoxicity due to its metabolites. This master thesis deals with the compound 7-phenoxytacrine, one of the promising tacrine derivatives, which is one of the candidates for potential use in the therapy of Alzheimer's disease. Due to the formation of hepatotoxic metabolites of tacrine after the biotransformation in human liver, it appears necessary to identify the emerging metabolites of 7-phenoxytacrine molecule. Within this master's thesis in vitro biotransformation study of 7-phenoxytacrine using human liver microsomes was performed. High performance liquid chromatography with tandem mass spectrometry was used to determine the parent substance and the seventeen 7-phenoxytacrine metabolites. The analytical method showed the formation of six monohydroxylated and eleven dehydroxylated metabolites of 7-phenoxytacrine. Thus, we concluded that hydroxylation is the major metabolic reaction after in vitro microsomal biotransformation. In addition to the identification of metabolites, a quantification and microsomal stability study, including the determination of the amount of...
HPLC determination of silybin diastereoisomers in plasma of laboratory animals
Kolářová, Petra ; Tesařová, Eva (advisor) ; Bednář, Petr (referee)
Silybin is the main component of silymarin, a standardized extract obtained from the seeds of milk thistle (Silybum marianum). Flavonolignan silybin has antioxidant, hepatoprotective, chemoprotective and antitumor activities. Natural silybin occurs as an approximately equimolar mixture of two diastereoisomers - silybin A and silybin B. Analytical separation of these diastereoisomers is possible but preparative separation is complicated. The biological activity of the silybin A is different from the silybin B. Silybin diastereoisomers are mainly conjugated to glucuronides and sulfates in organism. A mixture of both silybin diasteroisomers is used in the majority of reported biological, chemical and pharmacokinetic studies. For the first time, optically pure silybin A and silybin B were used for pharmacokinetic study in this thesis. The object of this work was determination of the concentration of free and total silybin in rats plasma in relation to time. Theoretical introduction describes the current state of the problem of chemistry, pharmacology and pharmacokinetics of silybin diastereoisomers. Second part is focused on the selection of appropriate analytical column, chromatographic method and suitable procedure for preparation of biological samples for the determination of the silybin...
LC-MS/MS study of phase one in vitro biotransformation of potential drugs against Alzheimer's disease
Kuřátková, Aneta ; Kučera, Radim (advisor) ; Váňová, Nela (referee)
No treatment that would completely stop the progression of Alzheimer's disease has not been found yet. Recently used tacrine showed good results in the treatment of Alzheimer's disease, however long-term use led to chronic hepatotoxicity due to its metabolites. This master thesis deals with the compound 7-phenoxytacrine, one of the promising tacrine derivatives, which is one of the candidates for potential use in the therapy of Alzheimer's disease. Due to the formation of hepatotoxic metabolites of tacrine after the biotransformation in human liver, it appears necessary to identify the emerging metabolites of 7-phenoxytacrine molecule. Within this master's thesis in vitro biotransformation study of 7-phenoxytacrine using human liver microsomes was performed. High performance liquid chromatography with tandem mass spectrometry was used to determine the parent substance and the seventeen 7-phenoxytacrine metabolites. The analytical method showed the formation of six monohydroxylated and eleven dehydroxylated metabolites of 7-phenoxytacrine. Thus, we concluded that hydroxylation is the major metabolic reaction after in vitro microsomal biotransformation. In addition to the identification of metabolites, a quantification and microsomal stability study, including the determination of the amount of...
Phenolic acids in plants
Klížová, Lucie ; Karlíčková, Jana (advisor) ; Janoušek, Jiří (referee)
CHARLES UNIVERSITY PHARMACEUTICAL FACULTY IN HRADEC KRÁLOVÉ DEPARTMENT OF PHARMACEUTICAL BOTANY Title of the Diploma thesis: FENOLIC ACIDS IN PLANTS Candidate: Lucie Klížová Supervisor: PharmDr. Jana Karlíčková, Ph.D. Diploma thesis 2020/2021, pp. 153 Phenolic acids belongs between secondary metabolites, which are part of fruits, vegetables, cereals and other plants of different families. For example, it can be plants of family Lamiaceae, Asteraceae and Ericaceae, which contain significant amounts of these substances. In plants phenolic acids play an important role and they have many human health-promoting effects including antioxidant, anti-inflammatory, antiviral, antibacterial, antifungal, anticancer activity and other. Plants containing phenolic acids are preferably also used as antidiabetics, expectorants, insecticides, hypolipidemics, cardioprotective and neurological compounds, etc. The content of these compounds in plants may be different according to monitored cultivar, the place of growth, the time of harvest and many other aspects. Presence, identification and subsequent quantification of individual phenolic acids are usually done through the HPLC and MS methods and total content of these compounds is determined through the Folin-Ciocalteu method. The diploma thesis is a literature...
Biotransformation of ferulic acid to sensory active compounds
Opial, Tomáš ; Pernicová, Iva (referee) ; Obruča, Stanislav (advisor)
The bachelor thesis deals with the biotransformation of ferulic acid to sensory active substances. The experiment was based on monitoring the biotransformation potential of selected microorganisms by high performance liquid chromatography (HPLC) method while the cultivation was performed in two parallel runs and samples with added ferulic acid were divided into 24-hour effect and 48-hour effect of ferulic acid on bacterial cultures. Thermophilic bacteria and halophilic bacterium Halomonas neptunia have been found to be the most suitable candidates for the biotransformation of ferulic acid to sensory active substances. In both samples of Schlegelella thermodepolymerans (DSM 15344 and DSM 15264) was formed 33 mg/l and 76 mg/l of vanillic acid and 81 mg/l and 71 mg/l of 4-vinylguaiacol after 24 hours of ferulic acid effect. In a sample with T. taiwanensis was formed 61 mg/l of vanillic acid and 32 mg/l of 4-vinylguaiacol after 48 hours of ferulic acid effect, and in a sample of R. xylanophilus was formed 56 mg/l of 4-vinylguaiacol. In the sample with H. neptunia after 24 hours of ferulic acid effect was formed 296 mg/l of vanillic acid, which was up to 59% of the conversion of the added ferulic acid and in a sample with H. organivorans after 24 hours of ferulic acid effect was formed 71 mg/l of vanillic acid. However, after 48 hours of ferulic acid effect, vanillic acid degraded. In addition to screening of biotransformation potential, the sequence of bacterial enzymes, involved in biotransformation, was also compared with protein sequences in the database using the BLAST search tool. The presence of genes encoding enzymes involved in biotransformation has been demonstrated for almost all used microorganisms except H. neptunia, for which no gene has been identified. The highest number of genes present in bacteria was with the enzymes feruloyl-CoA synthetase, enoyl-CoA hydratase/isomerase, acetoacetyl-CoA thiolase and vanillin dehydrogenase.

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