title: Improved 18F labeling of peptides with a fluoride-aluminum-chelate complex.
abstract: We reported previously the feasibility to radiolabel peptides with fluorine-18 ((18)F) using a rapid one-pot method that first mixes (18)F(-) with Al(3+) and then binds the (Al(18)F)(2+) complex to a NOTA ligand on the peptide. In this report, we examined several new NOTA ligands and determined how temperature, reaction time, and reagent concentration affected the radiolabeling yield. Four structural variations of the NOTA ligand had isolated radiolabeling yields ranging from 5.8% to 87% under similar reaction conditions. All of the Al(18)F NOTA complexes were stable in vitro in human serum, and those that were tested in vivo also were stable. The radiolabeling reactions were performed at 100 degrees C, and the peptides could be labeled in as little as 5 min. The IMP467 peptide could be labeled up to 115 GBq/micromol (3100 Ci/mmol), with a total reaction and purification time of 30 min without chromatographic purification.
authors.affiliation: Immunomedics, Inc., Morris Plains, New Jersey 07950, USA. bmcbride@immunomedics.com
authors.forename: William J
authors.initials: WJ
authors.lastname: McBride
authors.forename: Christopher A
authors.initials: CA
authors.lastname: D'Souza
authors.forename: Robert M
authors.initials: RM
authors.lastname: Sharkey
authors.forename: Habibe
authors.initials: H
authors.lastname: Karacay
authors.forename: Edmund A
authors.initials: EA
authors.lastname: Rossi
authors.forename: Chien-Hsing
authors.initials: CH
authors.lastname: Chang
authors.forename: David M
authors.initials: DM
authors.lastname: Goldenberg
mesh_terms: D000535:Aluminum / Q000737:chemistry*; D000818:Animals; D002614:Chelating Agents / Q000138:chemical synthesis / Q000737:chemistry* / Q000493:pharmacokinetics; D005459:Fluorides / Q000737:chemistry*; D005462:Fluorine Radioisotopes; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008024:Ligands; D051379:Mice; D008819:Mice, Nude; D015394:Molecular Structure; D010455:Peptides / Q000737:chemistry*; D014018:Tissue Distribution
chemical_list: D002614:Chelating Agents; D005462:Fluorine Radioisotopes; D008024:Ligands; D010455:Peptides; D000535:Aluminum; D005459:Fluorides