COMPUTATIONAL ELECTRONIC PROFILE OF THE INSECTICIDE IMIDACLOPRID AND ANALOGUES

Neonicotinoids, a class of neuro-active insecticides acting on the nicotinic acetylcholine receptors (nAChRs), are of great interest because of their high efficiency, low toxicity, broad insecticidal spectra and unique mode of action. The nAChRs ligands available on the market are involved in various pharmacological and pathophy siological processes. In this study, the molecular structures of imidacloprid, sulfoxaflor, and two analogues were investigated by means of Density Functional Theory and semiempirical quantum chemical methods including Austin Model 1 (AM1), Parametric-Method number 3 (PM3), and Re-parametrization of AM1 (RM1). In order to identify the key structural features responsible for the insecticidal activity, the electronic parameters (heat of formation, molecular electrostatic potential, reactivity Fukui indices, HOMO and LUMO energies) and ADME profiles were computed and analyzed for all neonicotinoids. The computation's outcome supports the experimental evidence regarding the importance of substituents and their positions at the heterocyclic rings for the insecticidal activity.