title: Synthesis and characterization of 11C-labeled fluoroclorgyline: a monoamine oxidase A specific inhibitor for positron emission tomography.
abstract: A new radioligand for monoamine oxidase type A (MAO-A), [11C]fluoroclorgyline, was synthesized from its desmethyl precursor by N-methylation reaction using [11C]methyl iodide with a radiochemical yield of 75-85%. The radiochemical purity of the product was more than 99% and the specific radioactivity was 7.4-18.5 GBq/micromol. The in vivo tissue distribution studies of [11C]fluoroclorgyline in mice demonstrated its high initial uptake and prolonged retention in the brain, comparable to those of [11C]clorgyline. A selective interaction with MAO-A in the accumulation of [11C]fluorclorgyline was confirmed by a competition experiment performed with the MAO-A specific inhibitor,clorgyline, and MAO-B specific inhibitor, l-deprenyl. These very desirable characteristics of [11C]fluoroclorgyline suggested that its 18F labeled counterpart, [18F]fluoroclorgyline, would have great potential as a longer-lived alternative to 11C labeled clorgyline for in vivo studies of MAO-A in the human brain with positron emission tomography (PET).
authors.affiliation: Osaka University of Pharmaceutical Sciences, Matsubara, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Ohmomo
authors.forename: M
authors.initials: M
authors.lastname: Hirata
authors.forename: K
authors.initials: K
authors.lastname: Murakami
authors.forename: Y
authors.initials: Y
authors.lastname: Magata
authors.forename: C
authors.initials: C
authors.lastname: Tanaka
authors.forename: A
authors.initials: A
authors.lastname: Yokoyama
mesh_terms: D000818:Animals; D002250:Carbon Radioisotopes; D003010:Clorgyline / Q000031:analogs & derivatives* / Q000737:chemistry / Q000493:pharmacokinetics; D008297:Male; D051379:Mice; D008815:Mice, Inbred Strains; D008996:Monoamine Oxidase Inhibitors / Q000737:chemistry / Q000493:pharmacokinetics; D014018:Tissue Distribution; D014055:Tomography, Emission-Computed / Q000379:methods
chemical_list: D002250:Carbon Radioisotopes; D008996:Monoamine Oxidase Inhibitors; C085565:fluoroclorgyline; D003010:Clorgyline