Development of Selective Butyrylcholinesterase Inhibitors Using (R)-Lipoic Acid-Polyphenol Hybrid Molecules

Abstract

A series of hybrid molecules between (R)-lipoic acid (ALA) and the acetylated or methylated polyphenol compounds were synthesized and their in vitro cholinesterase [acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE)] inhibition activities were checked. The IC50 values of all hybrid molecules for a BuChE inhibition were lower than those of the single parent compounds. Specifically, ALA-acetyl protected caffeic acid (11, ALA-AcCA) was shown as an effective inhibitor of BuChE (IC50 = 0.5 ± 0.2 µM) and also had a great selectivity for BuChE over AChE (more than 800 fold). Inhibition kinetic study indicated that 11 is a mixed inhibition type. Its binding affinity (Ki) value to BuChE is 1.52 ± 0.18 µM.