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Podophyllotoxin in eastern red cedar (Juniperus virginiana)
Olšar, Jiří ; Siatka, Tomáš (advisor) ; Kastner, Petr (referee)
Charles University Faculty of Pharmacy in Hradec Králové Department of Pharmacognosy Student: Jiří Olšar Supervisor: doc. PharmDr. Tomáš Siatka, CSc. Title of diploma thesis: Podophyllotoxin in eastern red cedar (Juniperus virginiana) This thesis describes the optimisation of the extraction process for quantity determination of podophyllotoxin in the leaves of Juniperus virginiana L. This determination was conducted through three different methods: the extraction in ultrasound bath, the extraction in the orbital shaker and the maceration in cold environment of 4 řC. Extractions were affected by various factors which were monitored, for instance time of extraction, temperature, and extraction solvents. The most efficient method appears to be the extraction in ultrasound bath with the use of methanol or a combination of phosphate buffer with ethyl-acetate.
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Optimalizace GC/MS metody stanovení silyl derivátů lignanů
BEDNÁŘ, Jan
The main goal of this work was optimization of GC-MS method for the analysis of lignans trimethylsilyl (TMSi-) derivatives of two model compounds hydroxymatairesinol(HMR) and enterolactone (ENTL). It included validation of GC-MS metod for TMSiHMR and TMSi-ENTL, comparison of chosen derivatization reagents and verification of time stability for TMSi-HMR. It was shown that TMSi-HMR and TMSi-ENTL provide a nonlinear calibration curve. Second order polynomial curve gave the best fitting and was used for method validation. N-Methyl-N-(trimethylsilyl)trifluoroacetamide activated I and II (Sigma Aldrcih) were selected as the best choice for simultaneous derivatization for HMR and ENTL mixture. Room temperature was confirmed to be appropriat for 3 days storage of TMSi-HMR. Also it was shown that storage at -80 °C preserve the lignan samples for at least 90 days storage.
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Natural sources of lignans in our diet
NĚMEC, Petr
This bachelor thesis deals with lignans (phytoestrogens) in our diet. Preliminary of the work is focused on the characteristic of lignans, which belongs to the not entirely explored group of substances contained in various parts of the plant. The work reviews the most utilized crops (soy, flax, and cereals), from which was isolated a large amount of lignans and other compounds with estrogenic activity. Furthermore, there is introduced the list of substances contained in crops and mechanisms of their action in the human body. Their use is very beneficial in the prevention of serious diseases, so-called civilization. At the end of the work, there are highlighted various methods of separation of lignans from plants.
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