title: One-step (18)F labeling of biomolecules using organotrifluoroborates.
abstract: Herein we present a general protocol for the functionalization of biomolecules with an organotrifluoroborate moiety so that they can be radiolabeled with aqueous (18)F fluoride ((18)F(-)) and used for positron emission tomography (PET) imaging. Among the β(+)-emitting radionuclides, fluorine-18 ((18)F) is the isotope of choice for PET, and it is produced, on-demand, in many hospitals worldwide. Organotrifluoroborates can be (18)F-labeled in one step in aqueous conditions via (18)F-(19)F isotope exchange. This protocol features a recently designed ammoniomethyltrifluoroborate, and it describes the following: (i) a synthetic strategy that affords modular synthesis of radiolabeling precursors via a copper-catalyzed 'click' reaction; and (ii) a one-step (18)F-labeling method that obviates the need for HPLC purification. Within 30 min, (18)F-labeled PET imaging probes, such as peptides, can be synthesized in good chemical and radiochemical purity (>98%), satisfactory radiochemical yield of 20-35% (n > 20, non-decay corrected) and high specific activity of 40-111 GBq/μmol (1.1-3.0 Ci/μmol). The entire procedure, including the precursor preparation and (18)F radiolabeling, takes 7-10 d.
authors: Laboratory of Molecular Imaging and Nanomedicine, National Institute of Biomedical Imaging and Bioengineering, National Institutes of Health, Bethesda, Maryland, USA.
authors: Zhibo
authors: Z
authors: Liu
authors: Department of Molecular Oncology, British Columbia Cancer Agency, Vancouver, British Columbia, Canada.
authors: Kuo-Shyan
authors: KS
authors: Lin
authors: Department of Molecular Oncology, British Columbia Cancer Agency, Vancouver, British Columbia, Canada.
authors: François
authors: F
authors: Bénard
authors: Department of Molecular Oncology, British Columbia Cancer Agency, Vancouver, British Columbia, Canada.
authors: Maral
authors: M
authors: Pourghiasian
authors: Laboratory of Molecular Imaging and Nanomedicine, National Institute of Biomedical Imaging and Bioengineering, National Institutes of Health, Bethesda, Maryland, USA.
authors: Dale O
authors: DO
authors: Kiesewetter
authors: Department of Chemistry, University of British Columbia, Vancouver, British Columbia, Canada.
authors: David M
authors: DM
authors: Perrin
authors: Laboratory of Molecular Imaging and Nanomedicine, National Institute of Biomedical Imaging and Bioengineering, National Institutes of Health, Bethesda, Maryland, USA.
authors: Xiaoyuan
authors: X
authors: Chen
mesh_terms: D001896:Boron Compounds / Q000737:chemistry*; D005462:Fluorine Radioisotopes / Q000737:chemistry*; D007553:Isotope Labeling / Q000379:methods*; D015282:Octreotide / Q000031:analogs & derivatives* / Q000737:chemistry
chemical_list: C000606315:AMBF3-TATE; D001896:Boron Compounds; D005462:Fluorine Radioisotopes; D015282:Octreotide