Characterization of Acetylcholinesterase Inhibitory Constituents from Annona glabra Assisted by HPLC Microfractionation.
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.
Tsai
Sheng-Fa
SF
School of Pharmacy, College of Medicine, National Taiwan University, 1, Section 1, Jen-Ai Rd, Taipei 10051, Taiwan, Republic of China.
Lee
Shoei-Sheng
SS
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
D001600:Berberine Alkaloids; D002800:Cholinesterase Inhibitors; C000605911:pseudocolumbamine; C000605894:pseudopalmatine; D000110:Acetylcholinesterase; C005413:palmatine