Abstract:  

Five alkaloids were isolated from the methanolic extract of the whole plant material of Glaucium aleppicum Boiss. & Hausskn. (Papaveraceae) using bioactivity-directed fractionation as part of a search for anticancer leads from medicinal plants of Jordan flora. Of these two were protopine-type alkaloids [allocryptopine (1) and protopine (2)], two were aporphine-type alkaloids [(+)-corydine (4) and (+)-isocorydine (5)], and (+)-norchelidonine (3). Compounds 3-5 were new to the species. The chemical structures of the isolated compounds were elucidated using a set of spectroscopic and spectrometric techniques, principally: MS, 1D-NMR (1H and 13C) and 2D-NMR (COSY and HMQC). Compounds 1-5 were tested for general cytotoxicity using BST. (+)-Norchelidonine was found to possess the highest activity with LC50 value of 0.41 ?g/mL and hence evaluated for cytotoxicity against a human cancer cell panel. (+)-Norchelidonine induced antiproliferative activity against human melanoma MV3 and colorectal SW480 cancer cell lines in a dose-dependent manner with IC50 values of 50 and 80 ?g/mL, respectively.