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Synthesis and evaluation of potential antimicrobial agents based on steroidal scaffold
Požárová, Pavla ; Krátký, Martin (advisor) ; Matouš, Petr (referee)
Antibiotic resistance represents a significant threat to humanity. To combat this trend, the development of new effective substances can be employed to potentially reverse its progression. Due to the broad range of biological activities exhibited by steroid structures, estrone was chosen as the starting material and was modified through various reactions. In total, fifteen new compounds were synthesized, which were tested for their antibacterial, antifungal, and antimycobacterial activities, and additionally for cholinesterases inhibition. The modification of estrone primarily involved two different approaches, resulting in the formation of hydrazones and esters. Twelve compounds were prepared through these steps. For the remaining three derivatives, changes in the starting materials or procedures were necessary. In the case of four compounds, it was necessary to synthesize one of the reactants. The yields ranged from 62% to 95% for hydrazones and from 8% to 54% for esters. The antibacterial activity was tested against four selected Gram-positive and Gram-negative strains. Antifungal activity was evaluated against four yeasts and filamentous fungi. Antimycobacterial activity was tested against five mycobacterial strains. All these methods utilized the microdilution broth method. The tested...
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Neuroactive steroids in human physiology and pathophysiology
Kubátová, Jana ; Hill, Martin (advisor) ; Fanta, Michal (referee)
The present diploma thesis is focused on the evaluation of steroid metabolome in body fluids in human pregnancy and parturition and also concentrates on the estimation of steroids in men with epilepsy (MWE) regarding the influence of epilepsy and its treatment with antiepileptic drugs (AEDs). The results obtained eventuate to the following conclusions: 1. They support the proposition about the key importance of corticoliberin for the timing of human parturition via stimulation of the steroidogenesis in the fetal zone of the fetal adrenal (FZ). Changes in steroid levels, however, much better predict the timing of parturition than the variation in corticoliberin. 2. The distribution of isoforms of placental oxidoreductases determines the excess of oxidized forms of the sex steroids and NAS in the fetus and the excess of their reduced forms in mother. This mechanism fundamentally affects the steroid bioactivity. The results indicate the role of NAS in pregnancy sustaining, their analgesic effect around parturition and their role in the pathophysiology of postpartum blues.
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The effect of maternal smoking on the homeostasis of the fetoplacental unit
Adamcová, Karolína ; Pařízek, Antonín (advisor) ; Miovský, Michal (referee) ; Procházka, Martin (referee)
Maternal smoking causes serious health danger for a mother but especially for a baby. Cigarette smoking produces complex steroidogenesis changes during the whole life of a woman. To study the influence of smoking on fetoplacental unit focusing on steroid hormons it was important first to concentrate on changes of the chosen steroids around the delivery. The first part of the thesis is dedicated to observe some chosen steroid hormons in peripartal period (37th week of the pregnancy, first stage of labor of mothers and mixed umbilical blood of their neonates) and to look for relations to the age of mother, the increase of the weight during the pregnancy, the type of the delivery and the sex of the baby. It was interesting to compare steroids in the relation to the type of the delivery: vaginal delivery versus planned caesarean section. Non-smoking women who delivered a boy spontaneously had significantly higher level of 17-OH-pregnenolone, progesterone, cortisol, corticosterone and significantly lower level of estradiol in comparison with non-smoking women who delivered a boy by a planned Caesarean section. In the maternal blood in the 37th week of the pregnancy there were found differences between steroids in accordance to the sex of the fetus but they were not found in the neonates' case. The age...
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Synthesis of ligands for farnesoid X receptor
Kašpar, Miroslav ; Chodounská, Hana (advisor) ; Kasal, Alexander (referee)
Farnesoid X receptor is mostly expressed in liver cells and its activation may be used for the treatment of cirrhosis causing diseases, especially biliary cirrhosis and nonalcoholic steatosis. These two latter diseases are most common in developed countries and, as of date, no effective treatments are available. Therefore, the aim of this project is the design and synthesis of novel bile acid analogues with subsequent biological evaluation towards farnesoid X receptor. Thus, a series of new compounds were designed using computational modeling studies and chemical synthesis was done to develop structure-activity relationships. Chemical structure analysis and purity was confirmed by conventional analytical methods. Finally, synthetic compounds were profiled against farnesoid X receptor in collaboration with the Pharmaceutical faculty of Charles University in Hradec Králové. Keywords: farnesoid X receptor, FXR, bile acids
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The interaction of kainate subtypes of glutamate receptors with steroid compounds.
Fraňková, Denisa ; Krůšek, Jan (advisor) ; Adámek, Pavel (referee)
Kainate receptors belong to the family of glutamate receptors, which include NMDA, AMPA and δ receptors. Glutamate receptors are widely found in the brain and therefore they are very dynamically investigated, especially from view of pharmacology, because there is great potential for finding new and more specific modulators which could be used in the treatment of neurodegenerative diseases. The aim of this work was to extend the knowledge about the influence of neurosteroids on homomeric kainate receptors (GluK1, GluK2, GluK3) in which is the study of modulation by neurosteroids still at the beginning. We have investigated interactions of homomeric kainate receptors with selected neurosteroids (pregnenolone sulfate, pregnanolone sulfate, dehydroepiandrosterone, dehydroepiandrosterone sulfate) by using patch clamp method in the configuration of whole-cell recording and also by using microfluorometry. We have found out that the biggest modulating effect on homomeric kainate receptors is caused by pregnenolone sulfate, which inhibits glutamate responses of these receptors. Keywords kainate receptor, glutamate, neurosteroids, steroids, patch-clamp technique
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The role of neuroactive steroids in pregnancy and their importance in prenatal diagnosticsSteroidogenesis in the third trimester of pregnancy and mechanisms leading to the start of labor
Pašková, Andrea ; Pařízek, Antonín (advisor) ; Procházka, Martin (referee) ; Tošner, Jindřich (referee)
Steroid hormones act through two mechanisms. The first is the classical genomic level, which acts at a relatively slow pace from hours to days. The second non-genomic mechanism of steroid activity can influence cellular function during seconds or even milliseconds. During pregnancy both mechanisms take place. Steroid hormones that act non-genomically and influence neuronal excitability are called neuroactive steroids. The aim of this study was to measure the levels of steroid hormones and examine their relationship to the physiology and pathophysiology of pregnancy. The physiological importance of increased placental progesterone production, lowered production of 5B-pregnanone steroids and increased activity of steroid sulfotransferase with gestational age have been intensely discussed. On the basis of our results, we have proposed an alternative mechanism of maternal progesterone synthesis during pregnancy (progesterone, or the gestagen stabilizing activity of the myometrium = continuation of pregnancy). In contrast to previous results our observations indicate that gestagens arise from precursors in the fetus (from pregnenolone sulfate). This mechanism is closely connected with the distribution of placental oxido-reductase. Data from this study show an increasing trend in the conversion of...
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Neuroactive steroids in human physiology and pathophysiology
Kubátová, Jana ; Hill, Martin (advisor) ; Fanta, Michal (referee)
The present diploma thesis is focused on the evaluation of steroid metabolome in body fluids in human pregnancy and parturition and also concentrates on the estimation of steroids in men with epilepsy (MWE) regarding the influence of epilepsy and its treatment with antiepileptic drugs (AEDs). The results obtained eventuate to the following conclusions: 1. They support the proposition about the key importance of corticoliberin for the timing of human parturition via stimulation of the steroidogenesis in the fetal zone of the fetal adrenal (FZ). Changes in steroid levels, however, much better predict the timing of parturition than the variation in corticoliberin. 2. The distribution of isoforms of placental oxidoreductases determines the excess of oxidized forms of the sex steroids and NAS in the fetus and the excess of their reduced forms in mother. This mechanism fundamentally affects the steroid bioactivity. The results indicate the role of NAS in pregnancy sustaining, their analgesic effect around parturition and their role in the pathophysiology of postpartum blues.
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