A new ~(18)F-heteroaryltrifluoroborate radioprosthetic with greatly enhanced stability that is labelled by ~(18)F-~(19)F-isotope exchange in good yield at high specific activity?

摘要

An ~(18)F-heteroaryltrifluoroborate was designed as a novel radioprosthetic for PET imaging. The stability of the new prosthetic was confirmed using ~(19)F-NMR spectroscopy: the solvolytic half-life was measured to be >16 000 min. Conjugation to RGD gave a stable radiotracer precursor for kit-like labeling by ~(18)F-~(19)F isotope exchange in 15 min. The total radiosynthetic procedure including HPLC purification requires <45 min. A plasma stability assay showed negligible defluoridation following 150 min and stability is corroborated by in vivo imaging showing minimal bone uptake. With Curie levels of ~(18)F-fluoride, yields of 20% and specific activities as high as 3 Ci mmol~(-1) (110 GBq mmol~(-1)) are achieved (n = 3).