Design, Characterization, Molecular Docking, and Insecticidal Activity of Some New Heterocyclic Compounds Containing Pyrazole Moiety against Spodoptera frugiperda (J.E. Smith) (Noctuidae: Lepidoptera)

Abstract

Objective: In 2016, Spodoptera frugiperda invaded Africa and caused serious economic damage. To protect crops from this dangerous pest, it was necessary to use all plant protection methods, like biological and chemical control. Producing powerful pesticides for the efficient management of this pest was the interest of many scientists around the world. Methods: A large number of chemical compounds were synthesized and tested for their toxicological activity against this new invading pest. The synthesized pyrazole derivatives are the subject of the first study on the harmful effects they cause, followed by structural relationships. Following the stated protocols, five pyrazole derivatives were synthesized as pure active ingredients, and their efficacy as potential insecticides against S. frugiperda was tested. Results and Discussion: The toxicity data exhibited that compound (VIb), with LC50 of 8.81 and 16.16 ppm, was more toxic than other synthesized insecticidal agents against the 2nd and 4th larval instars, respectively. The other checked compounds showed weak to strong insecticidal activity in the final category; the biological effects of the synthesized insecticidal agents on S. frugiperda under laboratory conditions were also investigated. These findings were validated via molecular docking investigations of the titled compounds against the gamma-aminobutyric acid receptor (GABA), which had PDB ID: 4COF.The results showed a strong interaction of (IVb) and (VIb) with the target 4COF protein with a high negative docking score.