Abstract
Charles University in Prague, Faculty of Pharmacy in Hradec Králové Department of Pharmaceutical Botany Candidate: MSc. Latifah Al Shammari Supervisor: Prof. Ing. Lucie Cahlíková, Ph.D. Title of Doctoral Thesis: Alkaloids of the genus Hippeastrum (Amaryllidaceae): isolation, identification, biological activity. Hippeastrum x hybridum cv. Ferrari was chosen based on results of previous screening studies for detailed phytochemical study for the purpose of isolation of the widest range of AAs. From 25 kg of fresh bulbs was obtained 29,46 g of purified alkaloidal extract, which was processed using column chromatography. Finally, 18 pure alkaloids were isolated including one new homolycorine-type alkaloid (9-O-demethyllycorenine). All compounds were identified by spectrometric techniques (GC-MS, ESI-MS, NMR, optical rotation) and by comparison with literature data. All alkaloids, isolated in sufficient amount, were tested for their biological activities associated with Alzheimer's disease (inhibition of hAChE, hBuChE, and POP), and cytotoxic activity. The inhibitory activity against human cholinesterases was determined in vitro by a modified Ellmanʼs spectrophotometric method. In the hAChE/hBuChE assay, except for 1,2- O,O'-diacetyl-dihydrolycorine which demonstrated a mild hBuChE inhibition potency...