|
|
Supercritical Fluid Extraction of Sesquiterpene Lactones from Laserpitium archangelica.
Sajfrtová, Marie ; Kraus, V. ; Wimmer, Z. ; Cerhová, Marie ; Vlk, M.
The aim of the work was to describe the SFE of two STLs, archangelolide and trilobolide, from seeds of Laserpitium archangelica (Apiaceae). The objectives consisted in: (a) optimizing, investigating the SFE condition (pressure, temperature and concentration ofmodifier in scCO2) effect on the yield and concentration of STLs in extract, (b) \nDetermination of the SFE kinetics of major components in the extracts and (c) comparing the SFE with pressurised liquid extraction (PLE) and Soxhlet extraction.\n\n\n
Fulltext: content.csg -  PDF
Plný tet: SKMBT_C22018100509461 - PDF
|
|
|
Seasonal variability of plant secondary metabolism (Artemisia sp.)
Koutská, Barbora ; Weiser, Martin (advisor) ; Dostál, Petr (referee)
Plant secondary metabolites (SM) are widely used by humans in many ways (pharmacy, biotechnology etc.). For making their use even more effective, it is important to know the seasonality of these chemicals in plants and what affect those changes. Three Artemisia species (Artemisia annua, A. absinthium, A. vulgaris) were cultivated during one vegetation season (from April to September 2016). Plant growth parameters and the beginning of their generative stages were observed, and leaf samples were collected regularly. Samples of some plants were collected repeatedly. A generalist herbivore (migratory locust), was used as a proxy for studying changes in plant secondary metabolism during the vegetation season. The results proved presence of defence secondary metabolites in plants except A. vulgaris species where the role of SM in defence was not shown. Levels of SM changed nonlinearly during the vegetational season and were time-dependent. Plant size did not influence the levels of SM in plants. Levels of SM were low at the beginning of the experiment followed by rapid increase and remaining on maximal levels. The plants which lost their biomass repetitively grew slowly and bloomed later than the plants which were clipped only once. A delay trend showing seasonality of the plant SM was not proved. In...
|
|
|
Regulation of C-MYC oncoprotein by natural drugs.
Filandr, František ; Novák, Petr (advisor) ; Flieger, Miroslav (referee)
Sesqiterpene lactones, a group of plant secondary metabolites which include Cnicin from Cnicus benedictus plant, have an anti-proliferative and anti-tumor effect on mammalian cells by activating specific signaling pathways while also generating oxidative stress. These factors combined drive tumor cell apoptosis. A few of these compounds have reached clinical trials and seem to be a promising chemotherapeutics. The focus of this work is to elucidate the effect of cnicin on C-MYC transcription factor and oncoprotein which is overexpressed in majority of tumor tissues, the effect of cnicin on DEAD-box RNAhelicase DDX3 and on the expression levels of several metabolic genes is also studied. Through the use of western blotting, immunodetection and qPCR it was found out, that cnicin is regulating the expression of C-MYC oncoprotein on both transcriptional and translational levels, while also lowering C-MYC protein stability probably through the effect on PIM-2 kinase. Cnicin is not affecting the total amount of DDX3 protein in cells, but it seems it is lowering its degradation rate. The possible transcriptional regulation of DDX3 by cnicin is still not clear and requires further research. With the use of LC-MS quantitative analysis and qPCR, it was found out that cnicin does not affect the metabolism of...
|
|
|
Mechanism of anti-cancer activity induced by sesquiterpene lactones.
Filandr, František ; Novák, Petr (advisor) ; Grobárová, Valéria (referee)
One way to stop tumor growth in organism is to induce differentiation, apoptosis or necrosis of tumor cells. A class of chemicals known to induce apoptosis and inhibit proliferation in leukemia cells are sesquiterpene lactones. One of these lactones is cnicin, a bitter tonic used in liqueurs, found in the plant Cnicus benedictus. The mechanism of this inhibition, is not fully understood but certain signaling pathways are suspected, mainly the recently discovered Hippo signaling pathway which controls the organ size and apoptosis in mammalian cells. The core kinase of this signaling pathway is MST1/2 protein and its activation by sesquiterpene lactone cnicin resulting in cleavage of its active N-terminal domain is observed in this work. Also, the effect of cnicin on down-regulating main oncoprotein deregulated in leukemia cells C-MYC is studied. In addition the results of q-PCR also show significant down-regulation of anti-apoptotic BCL2 and MCL1 genes and cMYC oncogene. (In Czech)
|
|
| |
guest ::
