Structure-activity relationships of cholinesterase inhibitors. I. Quantum mechanical study of affinities of phenyl N-methyl carbamates

Ab initio self-consistent field-molecular orbitals-linear combination of atomic orbitals calculations of electrostatic potentials were performed in a few regions about some phenyl N-methyl carbamate derivatives. A similar active-site conformation was assumed and a low-energy common conformation was obtained from semiempirical perturbative configuration interaction over localized orbitals calculations. The results indicate that affinity constants of the carbamate derivatives used for this study may be an outcome of phenyl ring electrostatic interactions with the active site.