Automated radiosynthesis of [¹⁸F]FBEM, a sulfhydryl site specific labeling agent for peptides and proteins

In the process of developing [¹⁸F]FBEM coupled target peptide, we have instituted a robust automated synthesis of [¹⁸F]FBEM, a sulfhydryl (-SH) site specific agent for radiolabeling of peptides and proteins. The radiosynthesis generated 1.67-3.89 GBq (45.1-105.1 mCi, 7.5-18.8% non-decay corrected yield) of [¹⁸F]FBEM from 22.2 GBq (600 mCi) of starting [¹⁸F]fluoride with molar activity of 31.8 ± 5.3 GBq/µmol (0.86 ± 0.14 mCi/nmol) (n = 3) at the end of synthesis. Radiochemical purity was greater than 98%, and total synthesis time was ~90 min.