Synthesis and Preliminary Biological Evaluation of Fluorescent Glycofused Tricyclic Derivatives of Amyloid β-Peptide Ligands

Fluorescent glycofused tricyclic compounds were synthesized through the domino conjugate oxa-Michael addition/aldol condensation of 2-hydroxybenzaldehydes with protected 3-oxoglucal by exploiting activation with an organocatalyst. Stereoselectivity was obtained by using (R)-(+)-α,α-diphenyl-2-pyrrolidinemethanol trimethylsilyl ether as the catalyst. All synthesized compounds presented good optical properties. All compounds were able to bind to synthetic amyloid β 1-42 peptide aggregates and to label amyloid plaques from brain sections of transgenic mice affected with Alzheimer's disease with staining properties comparable to thioflavin T. We synthesize new fluorescent glycofused tricyclic compounds able to bind to synthetic amyloid β 1-42 peptide aggregates and to label amyloid plaques in brain-tissue samples from transgenic mice affected with Alzheimer's disease.