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Basic chemical properties of fruits of selected cherry varieties
Chmil, Vojtěch ; Vítová, Eva (referee) ; Diviš, Pavel (advisor)
Diploma thesis is focused on chemical characteristics of nine selected sweet cherry varieties in nine parameters. Total and soluble solids were analyzed with these results 13.07–16.58 % for total and 14.67–19.50 °Brix for soluble solids, ash content 0,31–0,39 %, titratable acidity 5.44–9.91 g of malic acid per 1 kg of fresh cherries and formol number 14.45–23.73 ml of 0.1 M NaOH per 100 g of cherries. Then there were analyzed crude proteins content calculated from total nitrogen content determined by Kjeldahl method with results 0.41–0.68 % of crude proteins. Molecular absorption UV/VIS spectrophotometry was used for determination of total phenolic substances 0.30–0.89 g of gallic acid per 1 kg of cherries and total content of anthocyanins 128–848 mg of cyanidine-3-glucoside in 1 kg of cherries. Saccharides were determined by high performance liquid chromatography (HPLC) with ELSD detector. Content of glucose was 45.45–59.49 g/kg and fructose 46.88–60.01 g/kg. All results are compiled using tables and graphs and discussed. Experimental part of the thesis also describes principles and procedures of every analysis, so it can be reproduced. In theoretical part there is described botanical characteristic of cherry tree (Prunus avium L.), active substances contained in its fruits and their use in food industry. At the end of the theoretical part there is described instrumentation of high-performance liquid chromatography.
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Determination of selected chemical parameters of fruits of cultivated elderberry varieties
Hamalová, Veronika ; Vránová, Dana (referee) ; Vespalcová, Milena (advisor)
In this thesis was determinated selected chemical and nutritional parameters in the wild elderberry and 17 cultivated varieties of elderberry. The fruits was provided by the Research and Breeding Institute of Pomology Holovousy Ltd. The theoretical part deals describes elderberry, chemical composition of elderberry, especially biological active substances and its using not only food industry. Closer attention has been focused on effect of saccharides, anthocyanins and methods of their determination, specially determination by HPLC. The experimental part describes the various methods of determination of selected chemical and nutritional parameters. Total dry matter, content of total polyphenolic compounds, monomeric anthocyanin pigment and antioxidant activity was defined in all varieties of elderberry fruits. For some varieties was defined total soluble dry matter, content of organic acids and saccharides by various methods. In the end was compared the values from different methods varieties.
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Determination of the basic physical and chemical parameters of fruit juice from aronia
Zídková, Anežka ; Jurečková, Zuzana (referee) ; Diviš, Pavel (advisor)
Theoretical part of bachelor´s thesis contains basic information about aronia (Aronia melanocarpa) and examples of their use. There is a description of analysed substances, which are contained in aronia berries, and their importance for human organism. Experimental part is focused on determination of minerals, saccharides and vitamin C in aronia juices, syrups, nectar and aronia wine. Elements were determined by inductively coupled plasma optical emission spectrometry. Liquid chromatography was chosen for analysis of saccharides and vitamin C. All of analysed products are significant sources of macroelements. The highest concentrations of elements were determined in the sample named Aroniový skorosirup, which was sugared by vaporized apple juice. Fructose and glucose were contained in all products. Sucrose was only in products which were sugared. The amount of vitamin C was lower in consequence of pasteurization and storage.
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Fortification of selected cereal products
Hurtová, Jana ; RNDr.Renata Mikulíková, Ph.D. (referee) ; Márová, Ivana (advisor)
Present diploma thesis describes the study of bioactive compounds in the cereals. The work is focused on possible fortification of cereal products in order to increase nutritional value of final products which is reduced during the food processing and storage. Cereal grains are rich in several phenolic compounds, vitamins and minerals that reduce the risk of chronic diseases. The aim of this study was the preparation and analysis of model fortified cereals using lyophilized fruit originating from Czech Republic. A comparative analysis of content of bioactive substances in commercial and fortified products for children was performed too. The experimental part deals with a content of individual flavonoids by RP-HPLC/UV/VIS method, spectrophotometric determination of total and reducing saccharides and analysis of mono- and disaccharides by the HPLC/RI method as well. Differences in the content of individual flavonoids and saccharides after the application of acid hydrolysis of samples were investigated. The content of these compounds increased in most products because of their release from glycosidic forms. Presence of phenolics was confirmed in all analyzed cereals. Addition of 10% of lyophilized fruit/vegetable preparative (carrot, berries, apples) caused several fold increase of phenolics content in model mixtures. In commercially available cereal products there are relatively high differences in total phenolics content, proportionally to fruit component amount. The work included the spectrophotometric analysis of total polyphenols and flavonoids in a model physiological environment (artificial stomach juice) in which the hydrolysis of bound phenolic compounds occurred. The results of this study show that addition of lyophilized fruit seems to be a good way to increase the nutritional value and maintain the content of bioactive compounds in cereal products.
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Study of the prophylactic effect of glycoclusters on a model of bacterial adherence
Kurucová, Michaela ; Hodek, Petr (advisor) ; Kubíčková, Božena (referee)
Cystic fibrosis (CF), an autosomal recessive genetic disorder, arises from mutations in the CFTR gene encoding the CFTR protein, which primarily functions as a chloride channel in the body. The malfunction of chloride ion transport leads to multiple organ dysfunctions, with the most significant impact on the respiratory system. A hallmark of CF is the increased adhesion of bacteria, especially Pseudomonas aeruginosa (PA), to the lung epithelium, resulting from the formation of dense mucus and glycosylation modification in the lungs. The pathogenicity of PA is significantly contributed to by its virulent factors, specifically PA-IL and PA-IIL lectins, which facilitate adhesion to host cells by binding to surface receptors containing D-galactose (PA-IL) or L-fucose (PA-IIL). The main objective of this study was to demonstrate the ability of synthetically prepared multivalent inhibitors based on fucose and galactose to inhibit PA adhesion to lung epithelial cells. Trivalent glycoclusters designed to target the PA lectins were studied ex vivo using an adhesion test employing immortalized epithelial cells - the CuFi-1 (from a CF patient) and NuLi-1 (from a healthy individual) cell lines. A control PA strain, denoted as PAK (ST 1763), was utilized to monitor bacterial adhesion. For visualization and...
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Effect of artificial light at night on ecophysiological functions of plants
Ležal, Lukáš ; Konrádová, Hana (advisor) ; Lhotáková, Zuzana (referee)
Artificial light at night, as a significant source of anthropogenic pollution, has long been overlooked, both among the general public and in the scientific community as well as at the legislature level. Steps to reduce the negative impacts of artificial light at night have been taken late and to an insufficient extent, and it was the low general awareness that was one of the motivations for the bachelor thesis on this topic. Plants are a group of organisms that receive less attention than, for example, humans, although they far exceed them in ecological importance. Artificial light at night has the potential to alter the composition of plant communities and the food webs that are linked to them, of which humans are at the top. This is done by shifting plant phenological phases, disrupting the natural perception of day and night, modifying growth patterns and morphological characteristics, increasing irradiance stress or reducing the efficiency of photosynthesis. It is through a comprehensive knowledge of the interaction of plants with artificial light at night that society can effectively protect nature and introduce the necessary new standards and technologies to ensure sustainable development.
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Comparison of detection techniques for analysis of saccharides by capillary electrophoresis
Vlčková, Nikol ; Křížek, Tomáš (advisor) ; Kozlík, Petr (referee)
The aim of this work was to compare detection techniques of capillary electrophoresis to determine saccharides. The techniques were contactless conductivity detection, direct and indirect UV detection and fluorescence detection. Determined saccharides were glucose, fructose and sucrose, lactose was employed as internal standard. For conductivity detection the capillary has internal diameter of 20 µm. Voltage applied to capillary was 15 kV and temperature was 25 řC. 40mM NaOH was used as BGE. The calibration dependence was measured between 0,005 - 0,5 mg/ml. Repeteabilityof peak areas and migration times was measured in two concentration levels of 0,02 and 0,2 mg/ml. Detection and quantification limits were between 1,0 - 5,8 µg/ml. RSD values for repeatability of peak areas and migration times were between 0,01- 8,64 %. Difference in recovery from real concentration of analytes was between 7 - 22 %. For other detection methods the capillary had inner diameter of 50 µm. Voltage applied to capillary for indirect UV detection was 28 kV and temperature was 30 řC. Wavelength for detection was 207 nm and 50mM glycylgylycine with pH value of 12,8 was used as BGE. The calibration dependence was measured between 0,1-1 mg/ml. Repeteability of peak areas and migration times was measured in two concentration...
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Design, Synthesis, and Application of Novel Bifunctional (Thio)urea Organocatalysts Derived from Saccharides & Catalytic Asymmetric C−H Arylation of (η6-Arene)Chromium Complexes
Gergelitsová, Ivana ; Veselý, Jan (advisor) ; Sedlák, Miloš (referee) ; Urban, Milan (referee)
The first part of the thesis is focused on the design, synthesis, evaluation, and application of novel bifunctional (thio)urea organocatalysts derived from saccharides. Combination of H-bonding donor (thio)urea moiety with Lewis base active site in a single chiral scaffold (e.g., 1,2-trans-cyclohexyl, cinchona alkaloids, 1,1'-binaphthyl) is a popular motif in catalyst design. Only limited attention has been paid to the synthesis of bifunctional (thio)ureas using saccharides as a chiral scaffold. Saccharides bring the advantage of the availability of various diastereomeric forms. Moreover, they offer modification of steric, electronic, and solubility properties via O-substitution. Three types of novel organocatalysts were designed: C2-symmetrical thiourea/tertiary amines entirely derived from 2-amino-2-deoxy saccharides, thiourea/primary amines based on pentopyranose and a cyclohexane skeleton, and (thio)urea/tertiary phosphines containing both saccharide and α-amino acid unit. Both functional groups of organocatalysts of the first type are located on the saccharide unit, and it is the only element which fully determines stereoselectivity. This is an exceptional approach as the majority of saccharide-based organocatalysts use saccharide as a bulky electron- withdrawing substituent. However, the...
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Separation and determination of possible products of enzymatic cleavage of 4-nitrophenyl-N,N'-diacetyl-β-D-chitobioside using capillary electrophoresis
Velvarská, Romana ; Křížek, Tomáš (advisor) ; Kalíková, Květa (referee)
This work deals with the development and optimization of conditions of a method that can be used to compare the activity of the enzyme β-N-acetylhexosaminidase in hydrolysis of a natural substrate and a chromogenic substrate, which is often used in the study of enzyme kinetics. As a substrate, 4-nitrophenyl-N,N'-diacetyl-β-D-chitobioside was selected for cleavage. This oligosaccharide contains bond, which the enzyme cleaves in the natural substrate, and the bond that occurs in the chromogenic substrate. To determine the products arising from enzymatic hydrolysis of 4-nitrophenyl-N,N'-diacetyl-β-D-chitobioside, capillary zone electrophoresis was used. First, it was necessary to find the optimal composition of the electrolyte, its pH and concentration. The optimal background electrolyte was a solution of sodium tetraborate at a concentration of 25 mmol/l and a pH of 10.25. Subsequently, repeatability, calibration curves and linearity, limit of detection and limit of quantification were investigated. Repeatability of migration times ranged up to 0.6%, the repeatability of peak areas between 2.5 and 6.3%. Limits of detection were ranging from 0.005 to 0.120 mmol/l. Finally, the optimized method was successfully used to monitor the actual enzyme cleavage.
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Fast Dynamic Processes in Solution Studied by NMR
Šoltésová, Mária ; Lang, Jan (advisor) ; Mäler, Lena (referee) ; Batta, Gyula (referee)
Title: Fast Dynamic Processes in Solution Studied by NMR Spectroscopy Author: Mária Šoltésová Department: Department of low temperature physics, Charles University in Prague, and Department of Materials and Environmental Chemistry, Stockholm University Supervisor: doc. RNDr. Jan Lang, Ph.D., Department of low temperature physics, Charles University in Prague, and Prof. Jozef Kowalewski, Department of Materials and Environmental Chemistry, Stockholm University Abstract: Nuclear magnetic resonance (NMR) spectroscopy is capable to deliver a detailed information about the dynamics on molecular level in a wide range of time scales, especially if accompanied by suitably chosen theoretical tools. In this work, we employed a set of high-resolution NMR techniques to investigate dynamics processes in several weakly interacting molecular systems in solution. Van der Waals interactions play an important role in inclusion complexes of crypto- phane-C with chloroform or dichloromethane. The complex formation was thoroughly investigated by means of 1H and 13C NMR experiments along with the quantum- chemical density functional theory (DFT) calculations. We characterized kinetics, thermodynamics, as well as fine details of structural rearrangements of the complex formation. Internal dynamics of oligo- and...
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