title: Non-competitive inhibition of acetylcholinesterase by bromotyrosine alkaloids.
abstract: Fifteen bromotyrosine-derived alkaloids were isolated from the sponge Pseudoceratina cf. purpurea. The acetylcholinesterase-inhibiting activity of all the isolated compounds were examined; to purealidin Q, isoanomoian A, aplyzanzine A, and aplysamine 2 were active with IC50 values of 1.2, 70, 104, and 1.3 μM, respectively. On the other hand, antiproliferative activity against MCF-7 cells of aerophobin 1 gave an IC50 value of 0.8 μM. The Michaelis-Menten plots of the active alkaloids indicated that all the four compounds inhibited acetylcholinesterase in a non-competitive manner. The structures of the active compounds suggested that the N,N-dimethylaminopropyloxydibromotyramine moiety may play an important role in the enzyme-inhibiting activity, presumably on the anionic and hydrophobic binding sites.
authors.forename: Opeyemi J
authors.initials: OJ
authors.lastname: Olatunji
authors.forename: Akintayo L
authors.initials: AL
authors.lastname: Ogundajo
authors.forename: Ibrahim A
authors.initials: IA
authors.lastname: Oladosu
authors.forename: Kanokwan
authors.initials: K
authors.lastname: Changwichit
authors.forename: Kornkanok
authors.initials: K
authors.lastname: Ingkaninan
authors.forename: Supreeya
authors.initials: S
authors.lastname: Yuenyongsawad
authors.forename: Anuchit
authors.initials: A
authors.lastname: Plubrukarn
mesh_terms: D000110:Acetylcholinesterase / Q000378:metabolism*; D000470:Alkaloids / Q000737:chemistry* / Q000494:pharmacology*; D049109:Cell Proliferation / Q000187:drug effects; D002800:Cholinesterase Inhibitors / Q000737:chemistry* / Q000494:pharmacology; D004789:Enzyme Activation / Q000187:drug effects; D006801:Humans; D061986:MCF-7 Cells; D015394:Molecular Structure; D014443:Tyrosine / Q000031:analogs & derivatives* / Q000737:chemistry / Q000494:pharmacology
chemical_list: D000470:Alkaloids; D002800:Cholinesterase Inhibitors; C574829:aplysamine-2; C475724:bromotyrosine; D014443:Tyrosine; D000110:Acetylcholinesterase