Insecticidal Activity Evaluation of Phenylazo and Dihydropyrrole-Fused Neonicotinoids Against Cowpea Aphids Using the MLR Approach

This paper presents a QSAR study of a series of 24 dihydropyrrole-fused and phenylazo neonicotinoid derivatives, with insecticidal activity tested against Cowpea aphids (Aphis craccivora). In this regard, the conformational search ability of the OMEGA software, was employed to model neonicotinoid conformer ensembles, using molecular mechanics calculations based on the MMFF94s (the 94s variant of the Merck Molecular) force field. The minimum energy conformers were used to calculate structural descriptors, which were further related to the insecticidal activity (pLC₅₀ values), using the multiple linear regression approach. The genetic algorithm was used for variable selection and several criteria for internal and external model validation. A robust model (r² = 0.880, r²_adj = 0.855, q²_LOO = 0.827, s = 0.2098, F = 34.295) with predictive power (CCC_ext = 0.945, r²_m= 0.824) was obtained, using the QSARINS software. The developed model can be confidently used for the prediction of the insecticidal activity of new chemicals, saving a substantial amount of time and money.