One-step radiosynthesis of 4-[~18F]flouro-3-nitro-N-2-propyn-1 -yl-benzamide ([~18F]FNPB): a new stable aromatic porosthetic group for efficient labeling of peptides with fluorine-18

摘要

4-[~18F]flouro-3-nitro-N-2-propyn-1-yl-benzamide ([~18F]FNPB) was developed as a new stable aromatic prosthetic group for more efficient click labeling of peptides. A new aromatic precursor 3,4-dinitro-W-2-propyn-1-yl-benzamide was radio-fluorinated using [~18F]KF/K2.2.2 followed by HPLC purification to obtain the desired product [~18F]FNPB. [~18F]FNPB was synthesized with a 58% radiochemical yield, a specific activity > 350 GBq/ mumol, and radiochemical purity was exceeded 98% in 40 min. The in vitro stability studies showed no detectable radiodefluorination over 2 h in mouse plasma. The click labeling yield of three different peptides with [~18F]FNPB were all above 87%. The in vitro study suggests that [~18F]FNPB may be stable in vivo and could have general application in labeling peptides with high radiochemical yield for positron emission tomography applications.