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Preparation of optically pure compounds by stereoslective hydrogenation in a microreactor
Jaklová, Natalie ; Klusoň, Petr (advisor) ; Paterová, Iva (referee)
This bachelor Thesis is introducing an alternative approach to the synthesis of the pharmaceutically important compound (R)-4-chloro-3-hydroxybutyrate ((R)-CHBE). This compound is used as a precursor in the production of pharmaceutically valuable products, such as L-carnitine, (R)-4-amino-3-hydroxybutyric acid and (R)-4-hydroxy-pyrrolidone. At present time these chemicals are predominantly produced by using biochemical methods largely based on enyzmatic reactions in the presence of stereoselective carbonyl reductases. In this Thesis a new approach is described, which is based on stereoselective hydrogenation of ethyl-4-chloracetoacetate catalyzed by an optically pure ruthenium bis(phosphine) complex. The whole process was carried out in a microfluidic reactor system. This assembly is highly promising for a potential scale-up, studies of reaction kitetics, optimization of reaction and process conditions etc. For the reaction described above the optimal reaction conditions, such as temperature, pressure, solvent phase composition and flow rates of gas and liquid phases, were determined. Furthermore, the use of a suitable ionic liquid preserving the catalyst's chiral selectivity was described. Key words: (R)-4-chloro-3-hydroxybutyrate, L-carnitine, microfluid chip reactor, hydrogenation
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Measurement of L-carnitine effect by ergospirometrie
Paimová, Barbora ; Plachý, Vladimír (advisor) ; Jaroslav, Jaroslav (referee)
Measurement of effect of L-carnitine by ergospirometry Summary The intention is to determine the effect of L-carnitine on fatty acid metabolism. Values like volume of utilized oxygen, performance and respiratory quotient were chosen for evaluation. The study is a randomized and placebo-controlled. The testing was performed on a treadmill with gas sensing device Cortex Metalyzer 3B and sporttester Polar RS 400. The measurement was adjusted compared to the pre-set test program. The reason was detecting a change in fatty acid metabolism, which takes place under aerobic conditions and starts later. Participants were recreational and performance athletes. Paired t-test and percentage change were used for evaluation. There was no change in the volume of utilized oxygen, performance and respiratory quotient. This study does not match with the majority of similar trials, which indicate the reduction of the respiratory quotient, reduced lactate levels, markers of increased oxidation of fatty acids and the other markers of aerobic metabolism.
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Methods of monitoring the profile of carnitine metabolites in urine and use in clinical diagnosis
NOVÁKOVÁ, Martina
This study deals with the profiling of carnitine metabolites in the urine of the patients with breast cancer. L-carnitine is a chemical compound that is very important for metabolism of lipids, and therefore some current research suggests that it could serve as a means for the treatment of cancer affecting various organs or tissues. The theoretical part deals with the general characteristics and a description of the L-carnitine and its effect on the body. This part is divided into chapters that summarize various information about L-carnitine and acylcarnitines, for example the metabolism, different effects in the body including a description of responses to the lack of these substances, or methods that can be used for the detection of L-carnitine levels. Methods of monitoring L-carnitine were described in detail and were compared with previously published scientific studies. The authors of scientific studies show procedures, advantages and disadvantages of the proposed methods for determining L-carnitine and acylcarnitines, that were examined in this work in detail and the method for the determination of carnitine metabolites in urine has been proposed. A brief description of the most using methods for the determination of L-carnitine metabolites by liquid chromatography mass spectroscopy (LC / MS) is done the end of this part. I have been motivated with a positive results of studies and I have used this method for analysis in my work. In the research part of my study, the sample preparation protocol and conditions for the application of the method are described. The samples from the hospital of České Budějovice have been obtained from patients with fresh breast cancer diagnosis. In this part, the treatment of samples prior to detection, the used materials, equipment, chemicals, process and device settings for analysis were described. The method provided chromatograms and mass spectra of the individual substances. Samples of patients were compared with samples of control group of healthy women, which enabled us to observe possible differences. For clarity, the graph was drawn up and it was possible to monitor only slight differences between the levels of carnitine metabolites in women with breast cancer versus the control samples. This difference is not statistically significant, especially because the variability between individuals is higher of an order of magnitude than the actual differences between the two groups. This result is due to the fact that the study has not included additional information on patients such as information about their medications or health style, the overall condition of the body, etc. A detailed study requires a systematic and very time consuming work, which was not the aim of my thesis. Liquid chromatography with hydrophilic interactions method associated with mass detector used for monitoring of L-carnitine and its metabolites profiles gives positive results, is not time consuming, affordable and above all allow suitable for the detection of substances that have been selected for my work.
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Determination of carnitine in food supplements
Buchtová, Zuzana ; Hrstka, Miroslav (referee) ; Vespalcová, Milena (advisor)
This work deals with the determination of L-carnitine in food supplements. L-carnitine is a substance naturally occurring in organism, essential for metabolism of fatty acids. In food supplements is used especially for reducing body weight as a "fat burner". L-carnitine is popular with athletes for improve athletic performance. While data are not available to support these positive effects of carnitine, the positive results of carnitine supplementation in the medicine were found, mainly on cardiovascular system. The literary part of this study describes the properties and the use of carnitine in the diet of human. Furthermore, a review of methods used for determination of L-carnitine in variety of samples is mentioned. In the experimental section the efficiency of SPE method for preparation matrix of real samples was investigated. A cation exchange solid phase extraction seems to be the most effective. The optimal conditions for isolation of L-carnitine by SPE extraction were not developed. L-carnitine was determined in six various food supplements by reverse phase chromatography with UV/VIS detection.
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