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Identification and quantification of biomarkers of gastrointestinal diseases using mass spectrometry
Pospíšilová, Veronika ; Španěl, Patrik (advisor) ; Jelínek, Ivan (referee)
6 Abstract This thesis focuses on the identification and quantification of volatile metabolites in the exhaled breath that might be used as possible biomarkers of Gastroesophageal Reflux Disease. Animal tissue samples were exposed to conditions simulating the gastric environment to identify specific volatile compounds that would be chosen for real-time quantification in exhaled breath of GERD patients and healthy controls using selected ion flow tube mass spectrometry. Solid phase microextraction, was used in combination with gas chromatography mass spectrometry, for qualitative analyses of the headspace of these samples. Only acetic acid was significantly elevated and so it has been elected for the quantitative analysis in the breath of the patients. The median concentration of acetic acid measured by SIFT-MS in the exhaled breath of twenty-two GERD patients was found to be higher (85 ppbv) in comparison to the control group (31 ppbv). The results show that breath acetic acid could be valuable marker for GERD diagnosis and monitoring.
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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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Aroma active compounds in fruit distillates
Kocinger, Oskar ; Veselá, Mária (referee) ; Vítová, Eva (advisor)
This work deals with the identification of substances responsible for the taste and aroma of fruit spirits. Solid phase microextraction method coupled with gas chromatography and mass spectrometry (SPME-GC-MS) was used for extracting and identifying volatile substances present in a total of six samples of fruit spirits, namely 3 samples for plum distillate and 3 samples for apricot distillate. The results of the individual analyzes were compared and the most frequently occurring substances were identified. These compounds are most likely responsible for the typical aroma of fruit spirits of this kind.
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The content of aroma compounds in sweets
Polochová, Petra ; Vespalcová, Milena (referee) ; Vítová, Eva (advisor)
This bachelor thesis focuses on identification of aroma active substances in samples of non-chocolate sweets. The theoretical part deals with the legislation and technology of manufacturing non-chocolate sweets, characterization of aroma compounds including those which could be allergenic. Furthermore this thesis describes a method of their determination using solid phase microextraction and gas chromatography with mass spectrometry (SPME-GC-MS) is described. In the experimental part, the chosen method SPME-GC-MS method was used to identify volatile aroma active substances in selected samples of jelly sweets purchased in a conventional market. The substances that are potentially allergenic were also quantified. The single samples differ in number and type of volatile compounds depending on producer and flavour. Altogether 246 compounds were identified, of which 30 hydrocarbons, 66 alcohols, 7 ethers, 20 aldehydes, 24 ketones, 56 esters, 13 carboxylic acids, 3 phenols, 16 heterocyclic compounds, 6 lactones and 5 others (linalooloxide; methylsulphonylmethan; dimethylsulphoxide; 1,1-diisobuthoxy-isobutane and propanamide).
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Assessment of aroma active compounds in selected type of cheese
Dostálková, Andrea ; Sýkora, Michal (referee) ; Vítová, Eva (advisor)
This bachelor thesis deals with the aroma active compounds of Emmental and Moravský bochník types of cheeses, i.e. natural hard cheese with high heat curd. In the theoretical part these cheeses are characterized, their chemical composition is described as well as individual steps of their manufacturing process. After that a literature search focused on aroma active substances is made and the following methods are described: solid phase microextraction for their isolation and gas chromatography with mass spectrometry for detection. In the experimental part the selected SPME-GC-MS method is used to identify volatile aroma active compounds in cheeses with high heat curd bought on the market and samples of model cheeses manufactured at Tomas Bata University in Zlín with the use of various ratios of added dairy cultures. The differences among samples were found in the number and types of volatile compounds. A total of 129 compounds were identified in samples; of those 35 alcohols, 9 aldehydes, 24 ketones, 16 carboxylic acids, 23 esters, 1 ether, 16 hydrocarbons, 2 sulphurous and 3 nitrogenous compounds.
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Analysis of sensorially active substances contained herbal extracts
Koloničná, Markéta ; Vítová, Eva (referee) ; Mikulíková, Renata (advisor)
The peppermint (Mentha piperita), the salvia (Salvia officinalis), the lemon balm (Melissa oficinalis), the camomile (Matricaria chamomilla) and the valerian (Valeriana officinalis) are herbs with healing effects. Their ethanol extracts are used for food fortification or in a cosmetic industry. Substances contained in herbal extracts were analyzed in this thesis. The extracts were prepared by maceration. Next, they were analyzed by using a gas chromatography and a mass spectrometry. The aim of this thesis was an optimalization of the method used for the analysis of sensorially active substances. Then, herbal extracts were analyzed and concentration of sensorially active substances was determined.
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Changes of aroma active compounds during production of model cheese
Školová, Dominika ; Pořízka, Jaromír (referee) ; Vítová, Eva (advisor)
The aim of the work was identification of aroma active compounds in Moravský bochník cheese type, than discuss their changes during ripening and consider influence of aplication different rates of microbial cultures on number of volatile compounds. SPME-GC-MS was used for identification of volatile compounds. In total, 148 of volatile compounds were identified and 82 of them are considered as aroma active compounds. Three microbial cultures (their combination with predominant thermophilic or mesophilic culture) were used for making samples. The influence of predominant thermophilic/mesophilic culture on number of volatile compounds was not proved. From the point of view of sensory quality, combinations with predominant mesophilic culture proved to be more successful. During ripening, the number of identified compounds was reduced in all the combinations of cultures studied. The optimal time for ripening seems to be three months.
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Aroma active compounds of selected types of medical herbs
Pecinová, Ester ; Diviš, Pavel (referee) ; Vítová, Eva (advisor)
This thesis deals with aroma active compounds of selected types of medicinal herbs, specifically lavender (Lavandula officinalis), peppermint (Mentha piperita), sage (Salvia officinalis), St. John’s wort (Hypericum perforatum) and hyssop (Hyssopus officinalis). In the theoretical part the single herbs were characterized including botanical description, chemical composition, medicinal properties, adverse effects and the practical use; aroma active compounds present in herbs are also emphasized. Based on the literature search, gas chromatography coupled with mass spectrometry as currently the most frequently used method, was chosen for the assessment of aroma compounds. Solid Phase Microextraction was used for isolation of volatile compounds from dried herbs. Within experimental part of the work selected parameters of the SPME-GC-MS method were optimized, aroma compounds in samples of herbs were identified, and twenty four suspected fragrance allergens due to the Regulation (EC) N° 1223/2009 were also identified and quantified. Overall 69 compounds were indetified together with 2 allergens in lavender, 59 compounds including 5 allergens in peppermint, sage contained 49 compounds with 4 allergens included, 41 compounds were identified in St. John’s wort including 4 allergens and finally 64 compounds with 4 allergens included in hyssop.
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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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