Acetylcholinesterase inhibition studies of alkaloid components from Crinum asiaticum var. sinicum: in vitro 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 Crinum asiaticum var. sinicum resulted in the isolation of seven alkaloids (1-7), including one new dimeric compound, bis-(-)-8-demethylmaritidine (1). Their structures were elucidated using NMR and HR-ESI-MS. The absolute configuration of new compound 1 was established by circular dichroism spectroscopy. All isolated compounds were evaluated for their inhibitory effects on acetylcholinesterase (AChE) activity in vitro. Among them, compound 1 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 1 may be a potential candidate for effectively treating Alzheimer's disease.

Anti-inflammatory secondary metabolites from the stems of Millettia dielsiana Harms ex Diels.

A phytochemical investigation for the constituents of the stems of Millettia dielsiana Harms ex Diels resulted in the isolation of a new isoflavone glycoside, mildiside A (1), and 14 known compounds (2-15). Their chemical structures were determined using a combination of IR, NMR, MS, and optical rotation analysis, as well as comparison with the literature data. The ethanolic (EtOH) extract and several isolated compounds exert the inflammatory effect of nitric oxide (NO) production in lipopolysaccharide (LPS)-stimulated murine RAW264.7 macrophage cells.