Acetylcholinesterase inhibition studies of alkaloid components from var. : assessments by molecular docking and molecular dynamics simulations.

Alkaloids are among the most important and best-known secondary metabolites as sources of new drugs from medicinal plants and marine organisms. A phytochemical investigation of the whole plant of var. resulted in the isolation of seven alkaloids (-), including one new dimeric compound, bis-(-)-8-demethylmaritidine (). Their structures were elucidated using NMR and HR-ESI-MS. The absolute configuration of new compound was established by circular dichroism spectroscopy. All isolated compounds were evaluated for their inhibitory effects on acetylcholinesterase (AChE) activity . Among them, compound exhibited the most potent AChE inhibition. Moreover, molecular docking and molecular dynamics simulations were carried out for the most active compound to investigate their binding interactions and dynamics behavior of the AChE protein-ligand complex. Therefore, compound may be a potential candidate for effectively treating Alzheimer's disease.