Design and synthesis of some new carboxamide and propanamide derivatives bearing phenylpyridazine as a core ring and the investigation of their inhibitory potential on in-vitro acetylcholinesterase and butyrylcholinesterase

Bioorg Chem. 2018 Sep;79:235-249. doi: 10.1016/j.bioorg.2018.05.006. Epub 2018 May 8.


A series of new carboxamide and propanamide derivatives bearing phenylpyridazine as a core ring were designed, synthesized and evaluated for their ability to inhibit both cholinesterase enzymes. In addition, a series of carboxamide and propanamide derivatives bearing biphenyl instead of phenylpyridazine were also synthesized to examine the inhibitory effect of pyridazine moiety on both cholinesterase enzymes. The inhibitory activity results revealed that compounds 5b, 5f, 5h, 5j, 5l pyridazine-3-carboxamide derivative, exhibited selective acetylcholinesterase (AChE) inhibition with IC50 values ranging from 0.11 to 2.69 µM. Among them, compound 5h was the most active one (IC50 = 0.11 µM) without cytotoxic effect at its effective concentration against AChE. Additionally, pyridazine-3-carboxamide derivative 5d (IC50 for AChE = 0.16 µM and IC50 for BChE = 9.80 µM) and biphenyl-4-carboxamide derivative 6d (IC50 for AChE = 0.59 µM and IC50 for BChE = 1.48 µM) displayed dual cholinesterase inhibitory activity. Besides, active compounds were also tested for their ability to inhibit Aβ aggregation. Theoretical physicochemical properties of the compounds were calculated by using Molinspiration Program as well. The Lineweaver-Burk plot and docking study showed that compound 5 h targeted both the catalytic active site (CAS) and the peripheral anionic site (PAS) of AChE.

Keywords: Acetylcholinesterase inhibitory activity; Alzheimer’s disease; Butyrylcholinesteraseinhibitory activity; Molecular docking; Pyridazine.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acetylcholinesterase / metabolism*
  • Amides / chemical synthesis
  • Amides / chemistry
  • Amides / pharmacology*
  • Animals
  • Butyrylcholinesterase / metabolism*
  • Cell Survival / drug effects
  • Cholinesterase Inhibitors / chemical synthesis
  • Cholinesterase Inhibitors / chemistry
  • Cholinesterase Inhibitors / pharmacology*
  • Dose-Response Relationship, Drug
  • Drug Design*
  • Electrophorus
  • Horses
  • Mice
  • Molecular Docking Simulation
  • Molecular Structure
  • NIH 3T3 Cells
  • Pyridazines / chemistry
  • Pyridazines / pharmacology*
  • Structure-Activity Relationship


  • Amides
  • Cholinesterase Inhibitors
  • Pyridazines
  • Acetylcholinesterase
  • Butyrylcholinesterase