National Repository of Grey Literature 110 records found  1 - 10nextend  jump to record: Search took 0.04 seconds. 
Influence of polysaccharides on caffein absorption from beverages
Osecká, Karolína ; Márová, Ivana (referee) ; Pekař, Miloslav (advisor)
This bachelor thesis was focused on investigation of the interaction between the polysaccharide sodium hyaluronan (HA) and the alkaloid caffeine (CAF). The reason why this thesis was focused on study of aqueous solutions of hyaluronan with caffeine is that presence of polysaccharide can slow down the realising from hyalurona-caffeine complex. At first, it was determined whether the photophysical properties of caffeine reacts in different polarity solvents. Based on these results was studied the interaction of caffeine and hyaluronan using the fluorescence. Emission and excitation spectra of caffeine were observed. The HA of molecular weight of 1.7 MDa were chosen for the study of the interactions with the caffeine of concentration the caffeine contained in coffee. The results of interaction that would result to influence the emission properties of CAF, not show. In acidic solutions leading to the formation of various shapes of HA and by centrifugation it was determined whether HA in this form interacts with CAF, which was shown to decrease the absorbance of the supernatant in the CAF. The solution and the mixtures were measured in four types of environment in hydrochloric acid solutions at different pH. The influence of constant addition of caffeine and the HA of molecular weights of 1.7 MDa with different concentrations in different acidic solutions. As a part of the work was to determine how hyaluronan behaves in strongly acidic solution. And then determine the pH in model gastric juices after intake of Coca Cola and Kofola. The obtained results can be used as for description of the behavior of caffeine in the presence of selected polysaccharide.
Natural drugs in cancer treatment and their cytotoxicity
Hájková, Tereza ; Raudenská, Martina (referee) ; Provazník, Ivo (advisor)
The thesis deals with the natural substances in context with the cancer disease. The natural substances have a positive effect on the human organism and they are able to influence the viability and the growth of the cancer cells. The main mechanical device is to influence the mechanisms needed to start the apoptosis of the cancer cells and stopping further proliferation. The cancer cell lines utilization in the cancer disease is discussed in the thesis too. The thesis states common methods of determining the natural substances cytotoxicity. For the experimental part of the thesis it was chosen the MTT test method and the xCELLigence system for monitoring in real time. The mechanical device of the tested substance capsaicin in application on the prostate cell lines, tumorous PC3 and nontumorous PNT1A influence will be observed within the experimental part of the thesis.
Influencing of caffein absorption from cola-type beverages
Osecká, Karolína ; Márová, Ivana (referee) ; Pekař, Miloslav (advisor)
This diploma thesis was focused on basic physicochemical properties of caffeine and investigation of the interaction between the polysaccharide sodium hyaluronan (HA), pectin (PEC) or lignohumate (HUM) and the alkaloid caffeine (CAF). The reason why this thesis was focused on study of aqueous solutions of hyaluronan or pectin with caffeine is that the presence of polysaccharide- caffeine complex could be beneficial for slowing the absorption of caffeine. In the theoretical part of the diploma thesis there is described a group of alkaloids, which caffeine belongs to and also polysaccharides hyaluronic acid and pectin. The most attention has been paid to caffeine, its properties and effects on the human organism. This diploma thesis also deals with non-alcoholic beverages with caffeine, 4-methylimidazole, and phosphoric acid. The last chapter of the theoretical part is dedicated to fluorescence spectroscopy. In the experimental part of this work I deal with the basic properties of caffeine and interaction between the caffeine and selected polysaccharides or lignohumate. At first, the chemical and physical properties of caffeine were determined. Based on these results the interaction of caffeine and hyaluronan or pectin was studied by using the fluorescence and absorbance. The HA of molecular weight of 1,7 MDa and pectin from citrus fruits were chosen for the study of the interaction with the caffeine. These two substances were mixed with the caffeine of concentration contained in Coca-Cola. The results of interaction that would lead to the influence of the emission or absorption properties of caffeine, were not proved. As a part of the work there was determined how pectin behaves in strongly acidic solution and then there was monitored the pH, conductivity and solubility of caffeine in water by using thermogravimetry and visual experiments. The obtained results of the interaction of hyaluronan-caffeine, pectin caffeine or caffeine-lignohumate can be used for description of the behavior of caffeine in the presence of selected polysaccharides and natural organic substance.
Amaryllidaceae alkaloids of haemanthamine structural type and their semisynthetic derivatives as potential drugs in the treatment of Alzheimer's disease.
Peřinová, Rozálie ; Cahlíková, Lucie (advisor) ; Lapčík, Oldřich (referee) ; Mučaji, Pavel (referee)
Charles University, Faculty of Pharmacy in Hradec Králové Department of Pharmacognosy and Pharmaceutical Botany Candidate: Ing. Rozálie Peřinová Supervisor: prof. Ing. Lucie Cahlíková, Ph.D. Title of doctoral thesis: Amaryllidaceae alkaloids of haemanthamine structural type and their semisynthetic derivatives as potential drugs in the treatment of Alzheimer's disease. To deepen the knowledge about the Amaryllidaceae alkaloid haemanthamine, which was isolated at our workplace as part of previous phytochemical studies, derivatives of this alkaloid were synthesized. First, series of aliphatic (3-12) and aromatic ester derivatives (13-66) were prepared, and then, to compare the structure-activity relationship, ether derivatives (67-80) were prepared from the most active substituents. All synthesized compounds were identified using the following structural analysis methods: NMR, HPLC/MS, and HRMS, including testing physical properties such as optical rotatability. After structure confirmation, all derivatives were subjected to screening studies for their inhibitory potential against hAChE and hBuChE. The selected derivatives were tested for their inhibitory potential against another enzyme, GSK-3β, which plays a significant role in the pathogenesis of AD. In cooperation with the Faculty of Medicine in...
Alkaloids of Dicranostigma franchetianum (Prain) Fedde and their selected biological activity
Wijaya, Viriyanata ; Opletal, Lubomír (advisor) ; Šmejkal, Karel (referee) ; Klouček, Pavel (referee)
Charles University, Faculty of Pharmacy in Hradec Králové Department of Pharmacognosy and Pharmaceutical Botany Candidate: Viriyanata Wijaya, M.Sc. Supervisor: Prof. RNDr. Lubomír Opletal, CSc. Title of Doctoral Thesis: Alkaloids of Dicranostigma franchetianum (Prain) Fedde and their selected biological activity Dicranostigma franchetianum (Prain) Fedde (Papaveraceae) is one of the representatives of the small genus Dicranostigma Hook. f. & Thomson. D. franchetianum (Prain) Fedde has been selected for the phytochemical investigation according to the screening study. In the primary screening of the alkaloid extract for cholinesterases inhibition, the inhibitory value was high (hAChE/hBChE, IC50 g/ml; 1.67  0.11 and 3.85  0.31) and together at least 15 alkaloids were found in the extract. The primary ethanol extract was prepared from 11.8 kg of dry herb (Garden of Medicinal Plants, Faculty of Pharmacy in Hradec Kralove). Using common chromatographic methods, 21 isoquinoline alkaloids of various structural types were isolated. All compounds have been identified using various spectrometric techniques (GC-MS, HPLC- MS, and 1D- and 2D-NMR, optical rotatory. The alkaloids obtained in sufficient amounts were determined for human acetylcholinesterase (hAChE), human butyrylcholinesterase (hBChE), and...
Synthesis of Alkaloid-like Compounds with Quaternary Carbon Centers
Jansa, Petr ; Matoušová, Eliška (advisor) ; Baszczyňski, Ondřej (referee) ; Nováková, Veronika (referee)
Synthesis inspired by natural products has a long tradition in drug development. Because the structure of bioactive natural compounds is often very complex, preparation of their derivatives requires the development of specific synthetic procedures. This thesis focuses on derivatives of certain alkaloids from the Amaryllidaceae plant family as examples of such compounds. The thesis explores the possibilities of preparing polycyclic compounds that contain the structural motif present in tazettine, crinine, or mesembrine-type alkaloids. This motif includes a quaternary all-carbon center, for which a method involving a tandem cyclization/Suzuki coupling reaction and a halocarbocyclization was developed and optimized in this work. The scope of these reactions was studied, and variously substituted products containing oxygen and nitrogen cycles were prepared. Furthermore, methods for the synthesis of N-alkylated derivatives, dehydrohalogenation to form a double bond, or various mainly oxidative modifications of the cycle adjacent to the aromatic ring were developed. After developing a method for the preparation of enantiomerically enriched starting material, an asymmetric version of the entire synthesis was successfully performed. Finally, biological properties of selected compounds were studied. Some...
Alkaloids of Zephyranthes citrina (Amaryllidaceae): isolation, determination of structure, biological activity
Čejdová, Aneta ; Vrabec, Rudolf (advisor) ; Cahlíková, Lucie (referee)
Charles University, Faculty of Pharmacy in Hradec Králové Department of Pharmacognosy and Pharmaceutical Botany Candidate: Aneta Čejdová Title of diploma thesis: Alkaloids of Zephyranthes citrina (Amaryllidaceae): isolation, determination of structure, biological activity Key words: Amaryllidaceae, alkaloids, Zephyranthes citrina, biological activity, isolation From the selected alkaloidal fractions obtained from the bulbs of Zephyranthes citrina, six different alkaloids were isolated by chromatographic methods. They were identified using standard analytical methods (NMR, MS, HRMS, and optical rotation). The obtained compounds belong to the lycorine structural type (lycorine, galanthine, 6-oxonarcissidine, narcissidine) and haemanthamine structural type (maritidine, zephyranine E). The alkaloid 6-oxonarcissidine has not been described in the literature yet. The inhibitory activity against human AChE and BuChE was measured for the isolated alkaloids. Lycorine, galanthine, narcissidine, and maritidine have already been measured in many studies before; therefore, the attention was focused on the two less-known alkaloids: zephyranine E and 6-oxonarcissidine. However, the resulting IC₅₀ values of both alkaloids against human AChE and BuChE were above 100 µM, which indicates their insignificant...
Isolation of biologically active alkaloids from Papaver rhoeas with the use of separation methods
Češpivová, Barbora ; Jenčo, Jaroslav (advisor) ; Šafratová, Marcela (referee)
Charles University, Faculty of Pharmacy in Hradec Králové Department: Department of pharmacognosy and pharmaceutical botany Candidate: Barbora Češpivová Supervisor: RNDr. Jaroslav Jenčo, Ph.D. Title of diploma thesis: Isolation of biologically active alkaloids from Papaver rhoeas with the use of separation methods Alzheimer's disease is a neurodegenerative disorder characterized by progressive cognitive decline. This thesis focuses on the isolation of alkaloids from Papaver rhoeas L. as potential drugs for this disease. Isolating new substances in this area is significant due to the current inability to fully cure the patient through therapy, but rather only to positively influence the disease by delaying its severe stages. A phytochemical study was conducted on an alkaloid extract obtained from the aerial parts and immature capsules of Papaver rhoeas L. Based on biological testing of inhibitory activities against acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE), the fraction exhibiting the highest activity against BuChE, which had not been previously explored, was selected for the isolation of active compounds. This fraction was identified as PPR Fr-B and contained compounds PPR-9 and PPR-10. From the PPR Fr-B fraction, two aporphine-type alkaloids were isolated using separation...
Amaryllidaceae alkaloids of genus Narcissus and their biological activity.
Al Mamun, Abdullah ; Cahlíková, Lucie (advisor) ; Mučaji, Pavel (referee) ; Strnad, Miroslav (referee)
Charles University, Faculty of Pharmacy in Hradec Králové Department of Pharmacognosy and Pharmaceutical Botany Candidate: MSc. Abdullah Al Mamun Supervisor: Prof. Ing. Lucie Cahlíková, Ph.D. Title of Doctoral Thesis: Amaryllidaceae alkaloids of the genus Narcissus and their biological activity. Narcissus pseudonarcissus cv. Carlton has been chosen for the phytochemical investigation based on the screening study. An alkaloidal extract of 485 g has been obtained from 30 kg of fresh bulbs. Repeated liquid-liquid extraction gave 187 g of concentrated crude extract, which was separated by column chromatography (CC, Al2O3; 5800 g), followed by repetitive CC, preparative TLC, and crystallization. Thirteen previously described Amaryllidaceae alkaloids were obtained along with four novel compounds named carltonine A, B, C, and narciabduliine. All compounds were identified and characterized by spectrometric techniques (1D and 2D NMR, CD, and HRMS) and by comparison with data from the literature. Alkaloids isolated in sufficient amounts were used for further evaluation of their inhibition activity against human acetylcholinesterase (hAChE), butyrylcholinesterase (hBuChE) and prolyloligopeptidase (POP). Carltonine A and B demonstrated promising inhibition activity against the hBuChE enzyme with IC50 values of...
Synthesis and Reactivity of Enynes with Terminal Double Bond
Grobař, Bartoloměj ; Matouš, Petr (advisor) ; Opálka, Lukáš (referee)
Charles University in Prague Faculty of Pharmacy in Hradec Králové Department of organic and bioorganic chemistry Candidate: Bartoloměj Grobař Supervisor: PharmDr. Petr Matouš, Ph.D. Title of thesis: Synthesis and reactivity of enyns with terminal double bond This work focuses on synthesis of structures containing terminal vinyl moiety and their subsequent reactivity. We tested various approaches that lead to formation of enynes, which are then cyclized using gold complex catalyst into tetrahydropyridines. Both utilize the addition of propargylamine protected by 4-methoxybenzenesulfonyl group to substituted butynone and methoxyphenyl propiolates. Tetrahydropyridine molecules that are successfully created, are further derivatized forming polycyclic structures.

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