A fluorous and click approach for screening potential PET probes: Evaluation of potential hypoxia biomarkers

Radiopharmaceuticals for nuclear imaging are essentially targeting molecules, labeled with short-lived radionuclides (e.g., F-18 for PET). A significant drawback of radiopharmaceuticals development is the difficulty to access radiolabeled molecule libraries for initial in vitro evaluation, as radiolabeling has to be optimized for each individual molecule. The present paper discloses a method for preparing libraries of 18F-labeled radiopharmaceuticals using both the fluorous-based 18F-radiochemistry and the Huisgen 1,3-dipolar (click) conjugation reaction. As a proof of concept, this approach allowed us to obtain a series of readily accessible 18F-radiolabeled nitroaromatic molecules, for exploring their structure-activity relationship and further in vitro evaluation of their hypoxic selectivity.