Tracer name | Chemical structure | Features |
---|---|---|
Aminothiazolyl-ethenyl-benzoxazole derivatives | ||
 [11C] BF-227 (Kikuchi et al. 2010) |
| • Non-selective, affinities: see below for 18F-derivative |
• Investigated in MSA patients | ||
 [18F] BF-227: (Fodero-Tavoletti et al. 2009) |
| • Aß1-42 fibrils: KD1 = 1.3 nM |
• α-syn fibrils: KD = 9.6 nM | ||
Phenothiazine derivatives | ||
 SIL23 (Bagchi et al. 2013) |
| • Affinity and selectivity not optimal for in vivo imaging |
• Affinity α-synuclein: Ki = 58 nM | ||
• Screening tool | ||
 [18F] 2b (Zhang et al. 2014) |
| • Affinity α-synuclein: Ki = 49 nM |
• Selectivity α -syn vs. Aß: 2-fold | ||
• Selectivity α -syn vs. tau: 2.5-fold | ||
• Crosses blood–brain-barrier in healthy cynomolgus macaques | ||
• Shows sufficient initial uptake and wash-out | ||
• Higher selectivity desired | ||
 [11C] 2a (Zhang et al. 2014) |
| • Affinity α-synuclein: Ki = 32 nM |
• Selectivity α-syn vs. Aß: 3-fold | ||
• Selectivity α-syn vs. tau: 4-fold | ||
• Crosses blood–brain-barrier in cynomolgus macaques | ||
• Shows sufficient initial uptake and wash-out | ||
• Higher selectivity desired | ||
3-(Benzylidene) indolin-2-one derivatives | ||
 [18F] 46a: (Chu et al. 2015) |
| • Selective for α-synuclein: |
  o α-syn Kd = 8.9 nM | ||
  o Aß Kd = 271 nM | ||
  o Tau fibrils: 50 nM | ||
• High logP and presence of nitro group may limit its use for in vivo PET studies | ||
• Potential as secondary lead compound for further SAR studies |