Phenolic Bis-styrylbenzenes as β-Amyloid Binding Ligands and Free Radical Scavengers
摘要:
Starting from bisphenolic bis-styrylbenzene DF-9 (4), P-amyloid (A beta) binding affinity and specificity for phenolic bis-styrylbenzenes, monostyrylbenzenes, and alkyne controls were determined by fluorescence titration with beta-amyloid peptide A beta(1-40) and a fluorescence assay using APP/PSI transgenic mouse brain sections. Bis-styrylbenzene SA R is derived largely from work on symmetrical compounds. This study is the first to describe A beta binding data for bis-styrylbenzenes unsymmetrical in the outer rings. With one exception, binding affinity and specificity were decreased by adding and/or changing the substitution pattern of phenol functional groups, changing the orientation about the central phenyl ring, replacing the alkene with alkyne bonds, or eliminating the central phenyl ring. The only compound with an A beta binding affinity and specificity comparable to 4 was its 3-hydroxy regioisomer 8. Like 4, 8 crossed the blood brain barrier and bound to A beta plaques in vivo. By use of a DPPH assay, phenol functional groups with papa orientations seem to be a necessary. but insufficient, criterion for good free radical scavenging properties in these compounds.
Small molecules that protect against β-amyloid-induced cytotoxicity by inhibiting aggregation of β-amyloid
摘要:
Aggregated beta-amyloid (A beta) plays crucial roles in Alzheimer's disease (AD) pathogenesis, therefore blockade of Ab aggregation is considered as a potential therapeutic target. We designed and synthesized small molecules to reduce A beta-induced cytotoxicity by inhibiting A beta aggregation. The small molecules were screened via ThT, MTT, and cell-based cytotoxicity assay (A beta burden assay). Selected compounds 1c, 1d, 1e, and 1f were then investigated by evaluating their effects on cognitive impairment of acute AD mice model. Learning and memory dysfunction by injection of A beta(1-42) was recovered by administration of these molecules. Especially, 1d showed the best recovery activity in Y-maze task, object recognition task, and passive avoidance task with dose dependent manner. These results suggest that 1d has high potential as a therapeutic agent for AD. (C) 2012 Elsevier Ltd. All rights reserved.