title: Characterization of Acetylcholinesterase Inhibitory Constituents from Annona glabra Assisted by HPLC Microfractionation.
abstract: The active fraction of the EtOH extract of the stem of Annona glabra against acetylcholinesterase (AChE) was analyzed by combining HPLC microfractionation with a bioassay. The analytical-scale sample was fractionated by HPLC-DAD into 96-well microplates, which, after evaporation, were assayed against AChE. The active subfractions were scaled up by separation over semipreparative HPLC to give 20 compounds. Four of these, (7S,14S)-(-)-N-methyl-10-O-demethylxylopinine salt (3), S-(-)-7,8-didehydro-10-O-demethylxylopininium salt (10), S-(-)-7,8-didehydrocorydalminium salt (11), and 5-O-methylmarcanine D (17), were assigned as new natural products. In addition, compounds 10 and 11 represent the first natural occurrence of 7,8-didehydroprotoberberines. Compound 3, pseudocolumbamine (12), palmatine (15), and pseudopalmatine (16) showed anti-AChE IC50 values of 8.4, 5.0, 0.4, and 1.8 μM, respectively.
authors.affiliation: School of Pharmacy, College of Medicine, National Taiwan University, 1, Section 1, Jen-Ai Rd, Taipei 10051, Taiwan, Republic of China.
authors.forename: Sheng-Fa
authors.initials: SF
authors.lastname: Tsai
authors.forename: Shoei-Sheng
authors.initials: SS
authors.lastname: Lee
mesh_terms: D000110:Acetylcholinesterase / Q000187:drug effects*; D031041:Annona; D001600:Berberine Alkaloids / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology*; D002800:Cholinesterase Inhibitors / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology*; D002851:Chromatography, High Pressure Liquid; D020128:Inhibitory Concentration 50; D015394:Molecular Structure
chemical_list: D001600:Berberine Alkaloids; D002800:Cholinesterase Inhibitors; C000605911:pseudocolumbamine; C000605894:pseudopalmatine; D000110:Acetylcholinesterase; C005413:palmatine