Chlorinated tacrine analogs: Design, synthesis and biological evaluation of their anti-cholinesterase activity as potential treatment for Alzheimer's disease

Bioorg Chem. 2019 May:86:557-568. doi: 10.1016/j.bioorg.2019.02.033. Epub 2019 Feb 14.

Abstract

In search of potent acetyl cholinesterase inhibitors with low hepatotoxicity for the treatment of Alzheimer's disease, introduction of a chloro substitution to tacrine and some of its analogs has proven to be beneficial in maintaining or potentiating the cholinesterase inhibitory activity. Furthermore, it was found to be able to reduce the hepatotoxicity of the synthesized compounds, which is the main target of the study. Accordingly, a series of new 4-(chlorophenyl)tetrahydroquinoline derivatives, was synthesized and characterized. The synthesized compounds were evaluated for their in vitro and in vivo anti-cholinesterase activity using tacrine as a reference standard. Furthermore, they were investigated for their hepatotoxicity compared to tacrine. The obtained biological results revealed that all synthesized compounds displayed equivalent or significantly higher anti-cholinesterase activity and lower hepatotoxicity in comparison to tacrine. In addition, in silico drug-likeness of the synthesized compounds were predicted and their practical logP were assessed indicating that all synthesized compounds can be considered as promising hits/leads. Furthermore, docking study of the compound showing the highest in vitro anticholinesterase activity was performed and its binding mode was compared to that of tacrine.

Keywords: Alzheimer’s disease; Anti-cholinesterase activity; Chlorinated phenyl tetrahydroquinolines; Hepatotoxicity; Tacrine.

MeSH terms

  • Acetylcholinesterase / metabolism*
  • Alzheimer Disease / drug therapy*
  • Alzheimer Disease / metabolism
  • Animals
  • Anura
  • Cholinesterase Inhibitors / chemical synthesis
  • Cholinesterase Inhibitors / chemistry
  • Cholinesterase Inhibitors / pharmacology*
  • Dose-Response Relationship, Drug
  • Halogenation
  • Humans
  • Liver / drug effects
  • Liver / metabolism
  • Male
  • Molecular Docking Simulation
  • Molecular Structure
  • Rats
  • Structure-Activity Relationship
  • Tacrine / chemical synthesis
  • Tacrine / chemistry
  • Tacrine / pharmacology*

Substances

  • Cholinesterase Inhibitors
  • Tacrine
  • Acetylcholinesterase