Abstract

Donepezil, (RS)-2-[(1-benzyl-4-piperidyl) methyl]-5,6-dimethoxy-2,3-dihydroinden-1-one is a specific and
reversible inhibitor of acetyl cholinesterase, for the symptomatic treatment of Alzheimer’s disease and vascular
dementia. The universal force field molecular mechanics method was used to calculate the steric energy of (RS)-
2-[(1-benzyl-4-piperidyl) methyl]-5,6-dimethoxy-2,3-dihydroinden-1-one (Donepezil) using Arguslab software.
Molecular mechanics calculations were based on specific interactions within the molecule. These interactions
included stretching or compressing of bond beyond their equilibrium lengths and angles, torsional effects of
twisting about single bonds, the Van der Waals attractions or repulsions of atoms that came close together, and the
electrostatic interactions between partial charges in donepezil due to polar bonds. The steric energy calculated
for donepezil was 100.5289 kcal/mol. It was concluded that the minimum potential energy required for donepezil
to inhibit Acetyl cholinesterase is 100.5289 kcal/mol.