Table 4.
Binding affinities and Pharmacokinetics of featured α-syn PET-tracers.
| Tracer | Log D | α-syn Affinity [nM] | Aβ Fibrils Affinity [nM] | Tau Fibrils Affinity [nM] | Brain Uptake [%ID/g] | Brain Clearance [%ID/g] | ||||
|---|---|---|---|---|---|---|---|---|---|---|
| Ki | Kd | Ki | Kd | Ki | Kd | 5 min p.i. | 60 min p.i. | |||
| α-syn Fibrils | Human PD Homogenate | |||||||||
| [11C]SIL5 [209,210,211] | 3.79 | 32.1. 66.2. | 83.1 | NA | 110 | NA | 136 | NA | 0.953 | 0.158 |
| [125I]SIL23 [209,210] | 5.72 | 57.9 | NA | 148 | NA | 635 | NA | 230 | NA | NA |
| [18F]SIL26 [209,210,211] | 4.02 | 49.0 15.5. | 33.5 | NA | 103 | NA | 125 | NA | 0.758 | 0.410 |
| *14 [[213] | 4.2 1 | 79.5 | NA | NA | 113.3 | NA | 853.5 | NA | NA | NA |
| *20 [213] | 3.5 2 | 40.7 | NA | NA | 27.6 | NA | 53.7 | NA | NA | NA |
| [18F]46a [213] | 4.18 | 2.1 | NA | 8.9 | 142.4 | NA | 80.1 | NA | NA | NA |
| *11a,b [214] | 3.54 3 | 18.5 | NA | NA | 91.5 | NA | >1000 | NA | NA | NA |
| [125I]IDP-4 [222] | NA | NA | NA | 5.4 | NA | 16.24 | NA | NA | 0.45 (2 min p.i.) | 0.42 |
1,2 and 3 Calculated by ChemDraw Ultra 13.0 and Professional 15.1 respectively. * numbers given to the tracers in their respective publications. NA: data not available.