A new 18F-labelled derivative of the MMP inhibitor CGS 27023A for PET: Radiosynthesis and initial small-animal PET studies

The CGS 27023A derivative (R)-2-(N-((6-fluoropyridin-3-yl)methyl)-4-methoxyphenyl-sulphonamido)-N-hydroxy-3-methylbutanamide 1a was identified as a very potent matrix metalloproteinase inhibitor. Here, we describe a one-step radiosynthesis of the target compound [18F]1a. The syntheses of [18F]1a resulted in a radiochemical yield of 12.1±5.9% (decay-corrected), a radiochemical purity of 98.8±0.6%, and a specific activity of 39±27 GBq/μmol at the end of synthesis within 160±18 min from the end of radionuclide production (n=5). Initial small-animal PET studies in wild-type mice (C57/BL6) showed no unfavourable tissue accumulation of [18F]1a.