Summary of Representative THK Tau Probe Properties
| Property | 18F-THK-5105 | 18F-THK-5117 | 18F-THK-5351 |
| Affinity Kd (nM) | 4.4 | 11.5 | 2.9 |
| Selectivity tau/Aβ | +++/+ | +++/− | +++/− |
| Lipophilicity log P | 2.97 | 2.17 | 1.49 |
| Brain kinetics (2 min–to–10 min ratio) | 1.1 | 2.2 | 4 |
| Half-life of cerebellum SUV* (min) | 40–50 | 20–30 | 10–20 |
| References | Okamura et al. (13) | Harada et al. (18) | Harada et al. (32) |
↵* Half-life of peak SUV of cerebellum was estimated from time–activity curves in literature.
Symbols indicate results of binding intensities semiquantitatively analyzed by ARG-based binding assay. − indicates no binding of compound to tau or Aβ, + corresponds to weak binding, and +++ corresponds to strong binding.