From Proline to Chlorantraniliprole Mimics: Computer-Aided Design, Simple Preparation, and Excellent Insecticidal Profiles

Chlorantraniliprole (CHL), a favored agricultural insecticide, is renowned for its high efficiency and broad-spectrum effectiveness against lepidoptera insects. However, the urgency for new insecticide development is underscored by the intricate multistep preparation process and modest overall yields of CHL, along with the escalating challenge of insect resistance. In response, we have crafted CHL mimics from proline employing computer-aided drug design. Molecular docking analysis of CHL's interactions with the ryanodine receptor (RyR) revealed that the nitrogen atom within the pyrazole moiety does not engage in pivotal interactions. Its removal may not abolish bioactivity entirely but could substantially simplify the synthetic process, thereby enhancing atom economy. This revelation prompted the exclusion of nitrogen and the subsequent formation of a pyrrole ring, enabling the meticulous design of synthetic pathways characterized by cost-effective precursors, streamlined synthesis, the avoidance of toxic reagents, minimal instrumentation, and high yields in the pursuit of innovative RyR modulators. Among these modulators, A₁ and B₁, obtained with yields exceeding 60%, showcased exceptional insecticidal potency, with LC₅₀ values spanning from 0.12 to 1.47 mg L^-1 against P. xylostella and M. separate. The inhibitory effects of these two compounds on insect detoxification enzymes imply a reduced likelihood of eliciting resistance in comparison to CHL, a finding further corroborated by their insecticidal potency against resistant pests. Moreover, molecular docking, MD simulations, and DFT calculations provided valuable structural insights, potentially unraveling the superior insecticidal activity of these two molecules, and thus paving the way for developing more potent insecticides.