title: Assessment of enzyme inhibitory and antioxidant activities of lignans from Taxus baccata L.
abstract: Phytochemical investigations of Taxus baccata L. by successive chromatographic methods resulted in the isolation of the lignans lariciresinol (1), taxiresinol (2), 3'-demethylisolariciresinol-9'-hydroxyisopropylether (3), isolariciresinol (4), and 3-demethylisolariciresinol (5) as well as taxoids. Compounds 1-5 were evaluated for their acetylcholinesterase (AChE), butyrylcholinesterase (BChE), and lipoxygenase (LOX) inhibitory activities, which play a role in the pathogenesis of Alzheimer's disease (AD), by in vitro spectrophotometric methods, while they were also screened for their antioxidant capacity in 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging, ferrous ion-chelating effect, and ferric-reducing antioxidant power (FRAP) at 125, 250, 500, and 1000 microg ml(-1). All compounds exhibited a moderate inhibition against both BChE and LOX, whereas they were inactive towards AChE. The compounds displayed a great scavenging activity against DPPH especially at 500 and 1000 microg ml(-1). Besides, they were found to exert noteworthy reducing antioxidant power on ferric ions. In particular, the FRAP of compounds 2 (3.552 +/- 0.02), 4 (3.021 +/- 0.71), and 5 (3.533 +/- 0.01) were as high as that of the reference chlorogenic acid (3.618 +/- 0.01) at 1000 microg ml(-1). None of the compounds exhibited chelating ability against ferrous ions.
authors.affiliation: Department of Pharmacognosy, Faculty of Pharmacy, Gazi University, 06330 Ankara, Turkey. nurgun@gazi.edu.tr
authors.forename: Nurgun
authors.initials: N
authors.lastname: Kucukboyaci
authors.forename: Ilkay
authors.initials: I
authors.lastname: Orhan
authors.forename: Bilge
authors.initials: B
authors.lastname: Sener
authors.forename: S Ahmad
authors.initials: SA
authors.lastname: Nawaz
authors.forename: M Iqbal
authors.initials: MI
authors.lastname: Choudhary
mesh_terms: D000544:Alzheimer Disease / Q000188:drug therapy / Q000503:physiopathology; D000975:Antioxidants / Q000302:isolation & purification* / Q000494:pharmacology / Q000627:therapeutic use; D002091:Butyrylcholinesterase / Q000187:drug effects / Q000378:metabolism; D002800:Cholinesterase Inhibitors / Q000302:isolation & purification / Q000494:pharmacology / Q000627:therapeutic use; D004791:Enzyme Inhibitors / Q000302:isolation & purification* / Q000494:pharmacology; D016166:Free Radical Scavengers / Q000302:isolation & purification / Q000494:pharmacology; D006801:Humans; D016859:Lipoxygenase Inhibitors / Q000302:isolation & purification / Q000494:pharmacology; D010946:Plants, Medicinal / Q000737:chemistry; D020946:Taxus / Q000737:chemistry*; D014421:Turkey
chemical_list: D000975:Antioxidants; D002800:Cholinesterase Inhibitors; D004791:Enzyme Inhibitors; D016166:Free Radical Scavengers; D016859:Lipoxygenase Inhibitors; D002091:Butyrylcholinesterase