Polyfluorinated bis-styrylbenzenes as amyloid-β plaque binding ligands

Detection of cerebral beta-amyloid (A beta) by targeted contrast agents remains of great interest to aid the in vivo diagnosis of Alzheimer's disease (AD). Bis-styrylbenzenes have been previously reported as potential A beta imaging agents. To further explore their potency as F-19 MRI contrast agents we synthetized several novel fluorinated bis-styrylbenzenes and studied their fluorescent properties and amyloid-beta binding characteristics. The compounds showed a high affinity for Ab plaques on murine and human brain sections. Interestingly, competitive binding experiments demonstrated that they bound to a different binding site than chrysamine G. Despite their high logP values, many bis-styrylbenzenes were able to enter the brain and label murine amyloid in vivo. Unfortunately initial post-mortem F-19 NMR studies showed that these compounds as yet do not warrant further MRI studies due to the reduction of the 19F signal in the environment of the brain. (C) 2014 Published by Elsevier Ltd.