Coumarin, anthroquinone and stilbene derivatives with anticholinesterase activity.

Acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) are the key enzymes in pathogenesis of Alzheimer's disease (AD), which is characterized by a deficit in central cholinergic transmission. In the current study, AChE and BChE inhibitory activities of seven coumarin derivatives [umbelliferone (1), 4-methylumbelliferone (2), 4-hydroxycoumarin (3), scopoletin (4), 8-methoxypsoralen (5), bergapten (6), and iso-bergapten (7)], a furanocoumarin mixture obtained from Heracleum crenatifolium Boiss. (Umbelliferae), as well as of two anthroquinone derivatives [rhein (8) and aloe-emodine (9)] and one stilbene, rhapontin (10), were tested by the spectrophotometric method of Ellman using an ELISA microplate-reader at 1 mg mL(-1). Among them, the furanocoumarin mixture [(68.8 +/- 0.76)%], bergapten [(62.4 +/- 0.74)%], aloe-emodine [(57.2 +/- 1.32)%], scopoletin [(53.1 +/- 0.83)%], and 4-methylumbelliferone [(62.3 +/- 1.03)%] showed over 50% inhibition against AchE, while umbelliferone [(54.3 +/- 0.23)%], 4-methylumbelliferone [(80.9 +/- 1.17)%], scopoletin [(73.5 +/- 1.01)%], 8-methoxypsoralen [(67.1 +/- 0.98)%], as well as the furanocoumarin mixture [(76.7 +/- 0.95)%] had a notable anti-BChE effect.