Sesquineolignans and terpene-sesquineolignans: anti-acetylcholinesterase constituents from Illicium simonsii.

Chemical investigation of the aerial parts of Illicium simonsii resulted in the isolation of nine new compounds, simonsols A-E (1-5), simonsins A-B (7-8), terpene-sesquineolignans, clovanedunnianol (9), and p-menthadunnianol (10). Compound 5 was equilibrated with 7 as an inseparable mixture. The structures were elucidated by extensive NMR and MS analysis. Compounds 9, 10, and the mixture of 5 and 7 moderately inhibited acetylcholinesterase with IC50 values of 4.58 µM, 6.55 µM, and 10.34 µM, respectively.