The limited clinical efficacy of current symptomatic treatment and minute effect on progression of Alzheimer's disease has shifted the research focus from single targets towards multi-target-directed ligands. Here, a potent selective inhibitor of human butyrylcholinesterase was used as the starting point to develop a new series of multifunctional ligands. A focused library of derivatives was designed and synthesised that showed both butyrylcholinesterase inhibition and good antioxidant activity as determined by the DPPH assay. The crystal structure of compound 11 in complex with butyrylcholinesterase revealed the molecular basis for its low nanomolar inhibition of butyrylcholinesterase (Ki=1.09+/-0.12nM). In addition, compounds 8 and 11 show metal-chelating properties, and reduce the redox activity of chelated Cu(2+) ions in a Cu-ascorbate redox system. Compounds 8 and 11 decrease intracellular levels of reactive oxygen species, and are not substrates of the active efflux transport system, as determined in Caco2 cells. Compound 11 also protects neuroblastoma SH-SY5Y cells from toxic Abeta1-42 species. These data indicate that compounds 8 and 11 are promising multifunctional lead ligands for treatment of Alzheimer's disease.
Representative scheme of BCHE structure and an image from PDBsum server
Databases
PDB-Sum
6F7Q Previously Class, Architecture, Topology and Homologous superfamily - PDB-Sum server
FSSP
6F7QFold classification based on Structure-Structure alignment of Proteins - FSSP server
