title: Time-efficient and convenient synthesis of [(18)F]altanserin for human PET imaging by a new work-up procedure.
abstract: [(18)F]Altanserin, an important PET radioligand for the in vivo imaging of the 5-HT(2A) receptor, was synthesized from its precursor nitro-altanserin in DMF or DMSO at high temperatures of 150 degrees C in an overall radiochemical yield (EOB) of 23-25% after 75min. A new solid phase work-up procedure involving the acidification of the crude reaction mixture and a C18-SepPak-solid phase separation preceded the final HPLC purification. This led to a significantly reduced synthesis time as a result of a stable and early elution from the HPLC column using improved HPLC conditions (MeOH/THF/NaOAc 0.05N pH 5: 27/18/55, flow: 5 mL/min, Symetry Prep 7 microm C18 (Waters)). The synthesis was performed semi-automatically in a modified GE TracerLab synthesis module using an in-house-developed program. The synthesized [(18)F]altanserin was used in our ongoing human and animal PET imaging studies.
authors.affiliation: McConnell Brain Imaging Centre, Montreal Neurological Institute, McGill University, Montreal, Quebec, Canada. gassan.wassarweh@mcgill.ca
authors.forename: G
authors.initials: G
authors.lastname: Massarweh
authors.forename: M
authors.initials: M
authors.lastname: Kovacevic
authors.forename: P
authors.initials: P
authors.lastname: Rosa-Neto
authors.forename: A C
authors.initials: AC
authors.lastname: Evans
authors.forename: M
authors.initials: M
authors.lastname: Diksic
authors.forename: R
authors.initials: R
authors.lastname: Schirrmacher
mesh_terms: D000818:Animals; D001921:Brain / Q000000981:diagnostic imaging* / Q000378:metabolism*; D005462:Fluorine Radioisotopes / Q000737:chemistry / Q000493:pharmacokinetics*; D006801:Humans; D007553:Isotope Labeling / Q000379:methods; D007650:Ketanserin / Q000031:analogs & derivatives* / Q000737:chemistry / Q000493:pharmacokinetics; D049268:Positron-Emission Tomography / Q000379:methods*; D019275:Radiopharmaceuticals / Q000138:chemical synthesis; D044402:Receptor, Serotonin, 5-HT2A / Q000378:metabolism*; D013997:Time Factors
chemical_list: D005462:Fluorine Radioisotopes; D019275:Radiopharmaceuticals; D044402:Receptor, Serotonin, 5-HT2A; C071983:altanserin; D007650:Ketanserin