title: Enzymatic oxidation of the dopaminergic neurotoxin, 1(R), 2(N)-dimethyl-6,7-dihydroxy-1,2,3,4-tetrahydroisoquinoline, into 1,2(N)-dimethyl-6,7-dihydroxyisoquinolinium ion.
abstract: The dopamine-derived alkaloid, 1(R),2(N)-dimethyl-6,7-dihydroxy-1,2,3,4-tetrahydroisoquinoline [N-methyl(R)salsolinol] was found to be oxidized enzymatically into the more cytotoxic species, 1,2(N)-dimethyl-6,7-dihydroxyisoquinolinium ion, using enzyme sample prepared from human brain cortex. The values of the Michaelis constant and of the maximum velocity were 912 microM and 1,368 pmol/min/mg protein, respectively. The enzyme was not inhibited by inhibitors of monoamine oxidase, but was sensitive to semicarbazide. The oxidation is discussed in relation to the dopaminergic neurotoxicity of N-methyl-(R)salsolinol.
authors.affiliation: Department of Biosciences, Nagoya Institute of Technology, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Naoi
authors.forename: W
authors.initials: W
authors.lastname: Maruyama
authors.forename: J H
authors.initials: JH
authors.lastname: Zhang
authors.forename: T
authors.initials: T
authors.lastname: Takahashi
authors.forename: Y
authors.initials: Y
authors.lastname: Deng
authors.forename: P
authors.initials: P
authors.lastname: Dostert
mesh_terms: D002451:Cell Compartmentation; D002540:Cerebral Cortex / Q000201:enzymology*; D003010:Clorgyline / Q000494:pharmacology; D006801:Humans; D066298:In Vitro Techniques; D007546:Isoquinolines / Q000378:metabolism*; D007700:Kinetics; D009498:Neurotoxins / Q000378:metabolism*; D010084:Oxidation-Reduction; D012642:Selegiline / Q000494:pharmacology; D012663:Semicarbazides / Q000494:pharmacology
chemical_list: D007546:Isoquinolines; D009498:Neurotoxins; D012663:Semicarbazides; D012642:Selegiline; C010059:carbamylhydrazine; C036617:salsolinol; D003010:Clorgyline