title: Geissoschizine methyl ether, a corynanthean-type indole alkaloid from Uncaria rhynchophylla as a potential acetylcholinesterase inhibitor.
abstract: Geissoschizine methyl ether (1), a newly discovered strong acetylcholinesterase (AChE) inhibitor, along with six weakly active alkaloids, vallesiachotamine (2), hisuteine (3), hirsutine (4), isorhynchophylline (5), cisocorynoxeine (6) and corynoxeine (7) have been isolated from Uncaria rhynchophylla. Geissoschizine methyl ether (1) inhibited 50% of AChE activity at concentrations of 3.7 ± 0.3 µg mL(-1) while the IC(50) value of physostigmine as a standard was 0.013 ± 0.002 µg mL(-1). The mode of AChE inhibition by 1 was reversible and non-competitive. In addition, molecular modelling was performed to explore the binding mode of inhibitor 1 at the active site of AChE.
authors.affiliation: School of Life Science and Engineering , Lanzhou University of Technology, Lanzhou, P.R. China.
authors.forename: Zhong-Duo
authors.initials: ZD
authors.lastname: Yang
authors.forename: Dong-Zhu
authors.initials: DZ
authors.lastname: Duan
authors.forename: Juan
authors.initials: J
authors.lastname: Du
authors.forename: Ming-Jun
authors.initials: MJ
authors.lastname: Yang
authors.forename: Shuo
authors.initials: S
authors.lastname: Li
authors.forename: Xiao-Jun
authors.initials: XJ
authors.lastname: Yao
mesh_terms: D000470:Alkaloids / Q000032:analysis; D001665:Binding Sites / Q000235:genetics; D001681:Biological Assay; D002800:Cholinesterase Inhibitors / Q000032:analysis* / Q000737:chemistry / Q000494:pharmacology; D004365:Drugs, Chinese Herbal / Q000737:chemistry*; D026121:Indole Alkaloids; D007211:Indoles / Q000032:analysis* / Q000737:chemistry / Q000494:pharmacology; D020128:Inhibitory Concentration 50; D008958:Models, Molecular; D015394:Molecular Structure; D011485:Protein Binding; D032070:Uncaria / Q000737:chemistry*
chemical_list: D000470:Alkaloids; D002800:Cholinesterase Inhibitors; D004365:Drugs, Chinese Herbal; D026121:Indole Alkaloids; D007211:Indoles; C110832:geissoschizine methylether