Novel Tacrine-Benzofuran Hybrids as Potent Multitarget-Directed Ligands for the Treatment of Alzheimer's Disease: Design, Synthesis, Biological Evaluation, and X-ray Crystallography

J Med Chem. 2016 Jan 14;59(1):114-31. doi: 10.1021/acs.jmedchem.5b01119. Epub 2015 Dec 29.

Abstract

Twenty-six new tacrine-benzofuran hybrids were designed, synthesized, and evaluated in vitro on key molecular targets for Alzheimer's disease. Most hybrids exhibited good inhibitory activities on cholinesterases and β-amyloid self-aggregation. Selected compounds displayed significant inhibition of human β-secretase-1 (hBACE-1). Among the 26 hybrids, 2e showed the most interesting profile as a subnanomolar selective inhibitor of human acetylcholinesterase (hAChE) (IC50 = 0.86 nM) and a good inhibitor of both β-amyloid aggregation (hAChE- and self-induced, 61.3% and 58.4%, respectively) and hBACE-1 activity (IC50 = 1.35 μM). Kinetic studies showed that 2e acted as a slow, tight-binding, mixed-type inhibitor, while X-ray crystallographic studies highlighted the ability of 2e to induce large-scale structural changes in the active-site gorge of Torpedo californica AChE (TcAChE), with significant implications for structure-based drug design. In vivo studies confirmed that 2e significantly ameliorates performances of scopolamine-treated ICR mice. Finally, 2e administration did not exhibit significant hepatotoxicity.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alzheimer Disease / drug therapy*
  • Amyloid Precursor Protein Secretases / antagonists & inhibitors
  • Animals
  • Aspartic Acid Endopeptidases / antagonists & inhibitors
  • Behavior, Animal / drug effects
  • Benzofurans / chemical synthesis
  • Benzofurans / chemistry*
  • Benzofurans / pharmacology
  • Cell Line
  • Cell Survival
  • Chemical and Drug Induced Liver Injury / pathology
  • Cholinesterase Inhibitors / chemical synthesis
  • Cholinesterase Inhibitors / pharmacology
  • Crystallography, X-Ray
  • Drug Design
  • Humans
  • Male
  • Mice
  • Mice, Inbred ICR
  • Models, Molecular
  • Nootropic Agents / chemical synthesis
  • Nootropic Agents / chemistry*
  • Nootropic Agents / pharmacology
  • Structure-Activity Relationship
  • Tacrine / chemical synthesis
  • Tacrine / chemistry*
  • Tacrine / pharmacology
  • Torpedo

Substances

  • Benzofurans
  • Cholinesterase Inhibitors
  • Nootropic Agents
  • Tacrine
  • Amyloid Precursor Protein Secretases
  • Aspartic Acid Endopeptidases
  • BACE1 protein, human