Trifluoromethoxy-benzylated ligands improve amyloid detection in the brain using 19F magnetic resonance imaging

Abstract The chemical properties of probes that improve amyloid detection by non-invasive 19 F magnetic resonance imaging (MRI) are of interest. We synthesized benzoxazole compounds with trifluoromethoxy groups, and found that these compounds displayed sharp 19 F nuclear magnetic resonance (NMR) signals in an assay buffer. However, the intensities of the 19 F NMR signals were dramatically reduced in mouse brain lysates. Our results indicate that the inhibitory effect of brain tissue on the 19 F NMR signals from these probes can be attributed to the hydrophobicity of the tissue. These results highlight the importance of using hydrophilic 19 F-MRI agents to avoid the inhibitory effects of brain tissues on 19 F NMR signals.