Synthesis and Preliminary Biological Evaluation of p-［¹⁸F］FSTC

Carbonic anhydrase Ⅸ (CA Ⅸ) is a promising target for tumor hypoxia imaging, and some sulfamide compounds can specifically bind to human CA Ⅸ. In order to explore a novel positron emission tomography(PET) probe for detecting CA Ⅸ, the 1-(2-［¹⁸F］fluoroethyl)-N-(4-sulfamoylphenyl)-1H-1, 2, 3-triazole-4-carboxamide（p-［¹⁸F］FSTC） which has specific binding affinity to CA Ⅸ was radio-synthesized fast and efficiently by a “click chemistry” method. The labeling efficiency of p-［¹⁸F］FSTC is 90% and the total synthesis time is about 60 min. The radiochemical purity of p-［¹⁸F］FSTC is over 98% after HPLC purification. The stability of p-［¹⁸F］FSTC both in vitro and in vivo is high. The biodistribution of p-［¹⁸F］FSTC in normal mice shows that the clearance of p-［¹⁸F］FSTC in the blood is very slow; the uptake in spleen, lung, kidney and stomach is high. These preliminary results provide some experimental basis for further study of fluorine-18 labeled sulfamide as PET probes for tumor hypoxia imaging.