New fluorinated 1,4-bis-(arylaminomethyl)- and 1,4-bis-(arylaminomethylene)benzenes as fluorescent probes for amyloid plaques in Alzheimer's disease and transmissible spongiform encephalopathies

The research into selective ligands of misfolded protein plaques in Alzheimer's disease and in transmissible spongiform encephalopathies led to compound 3, based on the Congo Red framework and bearing two trifluoromethoxy groups. Histochemical experiments on human brain tissues showed intense fluorescent staining of fibrillary deposits in both pathologies.