Design, synthesis, and biological evaluation of glycine-based molecular tongs as inhibitors of Abeta1-40 aggregation in vitro

A series of N-terminus benzamides of glycine-based symmetric peptides, linked to m-xylylenediamine and 3,4′-oxydianiline spacers, were prepared and tested as inhibitors of β-amyloid peptide Aβ_1–40 aggregation in vitro. Compounds with good anti-aggregating activity were detected. Polyphenolic amides showed the highest anti-aggregating activity, with IC₅₀ values in the micromolar range. Structure–activity relationships suggested that π–π stacking and hydrogen-bonding interactions play a key role in the inhibition of Aβ_1–40 self-assembly leading to amyloid fibrils.