Butyrylcholinsterase inhibitors from two Ficus species (Moraceae)

Abstract

Alzheimer’s disease (AD) is the most common form of dementiaand mainly afflict people over 65 years of age. AD is characterized by a progressive memory loss that leads to a profound emotional disturbance in later stages.As no safe and effective drug is yet available for the treatment of AD,secondary metabolites from plants may be instrumental in meeting this challenge. From this work, 29 compounds were isolated and fully characterized and six of them:β-isolutéon (11), dehydroferreirin (12),lupiwighteon hydrate (13),Aviprin (24), blumenol A (26)andp-menthane-3,6-diol(27) have never been previously reported from the genus Ficus. This study also reports the complete 1H NMR assignment of lupiwighteon hydrate (13) for the first time.All the isolated compounds were purified through usual chromatographic methods and their structures established by the means of NMR data. Some isolated compounds as well as methanolic crude extracts were evaluated for their inhibitory potential against both acetyl- and butyrylcholinesterase enzymes by Ellman method. None of the crude methanolic extract showed response against tested enzymes. However, the ability of some isoflavonoids and coumarin from Ficus pumila Linn and Ficus thonningii Blume to inhibit cholinesterase has been evaluated.Alpinumisoflavon (5), lupiwighteonhydrate (13), two isoflavones and aviprin(24), a furanocoumarin showed good inhibitory activities against butyrylcholinesterase but not against acetylcholinesterase using eserin/galantamine as positive controle. These results are in agreement with the ethnobotanical uses of these plants and indicated that this activity could contribute significantly to the pharmacological properties of these species.