Synthesis Of F-18-Labelled Biotin Analogues

A one-step F-18-labelling strategy was used to prepare three labelled analogues of the vitamin biotin, which can be useful as tracers because of biotin's high affinity for avidin. The labelled compounds were obtained in decay-corrected yields of up to 35% and specific radioactivity of 320 GBq/mu mol. When evaluated in situ, the analogues showed good affinity for avidin: 60-75% of the radiolabelled compounds were bound to avidin within 5 minutes. The binding was site-specific, as shown by blocking experiments with native biotin.