Abstract:
In the field of nuclear medicine molecular imaging,
18F-fluoro-labeling methods based on intermediate molecule containing
18F-fluoro (i.e. prosthetic groups) has mild reaction condition, fine chemo-selectivity and simple purification for product. Therefore, the indirect
18F-fluoro-labeling via prosthetic group is a classical strategy in the development of tracers for positron emission tomography(PET). 2-
18F-fluoro-2-deoxy-D-glucose (
18F-FDG), which has simple scaffold, high hydrophilicity and easy accessibility, is the most popular tracer in PET practice and ideal prosthetic molecule for
18F-fluoro-labeling. In this paper, we review related methodological progress in literatures. The methodological parameters and product properties in these reports are compared and analyzed. Overall, several
18F-fluoro-labeling solutions employing
18F-FDG have emerged, including enzymic method, oxime formation, sulfydryl ligation and click chemistry. They were tried in the
18F-fluoro-labeling of small molecules, peptides, enzymes and nanoparticles. New technology such as microfluidic reactor was applied in some solutions aforementioned. Glycosylation and
18F-fluoro-labeling of precursor molecule can be achieved synchronically by the conjugation with
18F-FDG. Consequently, the
in vivo bio-kinetics of labeling product are significantly improved. Although the
18F-fluoro-labeling employing
18F-FDG needs multi-step reaction and especial modification in precursor, it is generally a feasible and valuable indirect labeling strategy.