Extract from milk thistle (Silybum marianum (L.) Gaertn., synonym Carduus marianus L., Asteraceae) silymarin contains among others primarily bioactive flavonolignans. They have hepatoprotective and antioxidative effects and also anticancer, chemoprotective, dermatoprotective and hypocholesterolemic activity. This thesis focuses on the preparation of metabolites of the second phase of biotransformation unexplored flavonolignans 2,3-dehydrosilybin (DHSB), silychristin (SCH), 2,3-dehydrosilychristin (DHSCH). Pure sulfated derivatives were prepared using aryl sulfotransferase from Desulfitobacterium hafniense and p-nitrophenyl sulfate (p- NPS) as a donor. Flavonolignans yield exclusively monosulfates at the position C- 20 (C-19 in the case of silychristin and 2,3-dehydrosilychristin), except for 2,3- dehydrosilybin that gives also the 7,20-disulfated derivatives. For all samples were made antioxidant tests - DPPH assay (the highest activity had 2,3-dehydrosilychristin sulfate: IC50= 7,87 µM), Folin-Ciocalteau reduction assay (the highest activity had 2,3-dehydrosilychristin: 1,58 ekvivalents of gallic acid), ABTS+ scavenging (the highest activity had silychristin: 1,50 ekvivalents of vitamin C), inhibition of microsomal lipid peroxidation (the highest activity had 2,3-dehydrosilybin: IC50 = 10,6 µM),...

The object of this thesis was the study on the pharmacokinetics and biotransformation of selected abused new synthetic drugs, specifically belonging to cathinone and aminoindane groups, in experimental rats. This work consisted of two parts: a biotransformation study of mephedrone, methylone, 5,6-methylenedioxy-2- aminoindane (MDAI) and a distribution profile study of mephedrone, methylone, MDAI and naphyrone. This document is presented as a commentary to the original papers, which were published in peer reviewed journals. The samples of blood and tissue (brain, lungs, liver) were taken at specific times after a subcutaneous single bolus dose of the studied drugs. The urine samples for the biotransformation studies were collected over a 24-hour period following the sc. dose. The LC/HRMS method was used for metabolite detection and quantitative analysis. Our findings not only included testing metabolites of the aforementioneddrugs against the synthesized reference standards, but also discovering previously unknown metabolites of these drugs. Ten phase I and five phase II metabolites aside from the parent drug were identified in urine after mephedrone administration by comparison of their spectra against those of reference standards and/or MS2 spectra of previously identified metabolites. The main...