Anti-Acetylcholinesterase Alkaloids from Annona glabra Leaf

Abstract

Bioassay guided fractionation and separation of the EtOH extract of Annona glabra leaf against acetylcholinesterse led to the characterization of 15 alkaloids. Among them, (–)-actinodaphnine (2) and (–)-(6a S,7 R)-7-hydroxyactinodaphnine (9) are new aporphines, although (+)-2 and (±)-2 have been found in several plants. Their structures were established by spectroscopic analysis. (-)-Anolobine (5) and (-)-roemeroline (8) showed moderate inhibitory activity against eel acetylcholinesterase with IC50 values of 22.4 and 26.3 μM, respectively.