A potent acetylcholinesterase inhibitor from Pancratium illyricum L.

Plants belonging to the Amaryllidaceae contain an exclusive group of alkaloids, known as sources of important biological activities. In the present work, Pancratium illyricum L., a species belonging to this family and endemic of Sardinia (Italy), was investigated for its alkaloid content. Fresh bulbs and leaves were processed separately. Standard extraction and purification procedures were applied to obtain fractions and compounds for GC-MS and NMR analysis. In addition to eight already known alkaloids (1-8), 11α-hydroxy-O-methylleucotamine (9) was isolated for the first time and its structure completely determined by one and two-dimensional 1H and 13C NMR spectroscopy. This new galanthamine-type compound exhibited a pronounced in vitro acetylcholinesterase (AChE) inhibitory activity (IC 50 = 3.5 ± 1.1 μM) in comparison to the reference standard galanthamine hydrobromide (IC50 = 1.5 ± 0.2 μM).