Structure Elucidation and Cholinesterase Inhibition Activity of Two New Minor Amaryllidaceae Alkaloids.

Two new minor Amaryllidaceae alkaloids were isolated from × cv. Ferrari and cv. Carlton. The chemical structures were identified by various spectroscopic (one- and two-dimensional (1D and 2D) NMR, circular dichroism (CD), high-resolution mass spectrometry (HRMS) and by comparison with literature data of similar compounds. Both isolated alkaloids were screened for their human acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) inhibition activity. One of the new compounds, a heterodimer alkaloid of narcikachnine-type, named narciabduliine (), showed balanced inhibition potency for both studied enzymes, with IC values of 3.29 ± 0.73 µM for AChE and 3.44 ± 0.02 µM for BuChE. The accommodation of into the active sites of respective enzymes was predicted using molecular modeling simulation.