A novel sesquiterpene alkaloid from Zanthoxylum piasezkii as a promising antifeedant against Tribolium castaneum

Against the backdrop of substantial post-harvest losses inflicted by storage pests, the discovery of novel natural alternatives to synthetic insecticides is imperative. A novel sesquiterpene alkaloid, 6-cadinenedihydrochelerythrine, with promising antifeedant activity against the storage pests of Tribolium castaneum was isolated from Zanthoxylum piasezkii Maxim. roots. Structural characterization was conducted using nuclear magnetic resonance (NMR), high resolution electrospray ionization mass (HR-ESI-MS), and vibrational circular dichroism (VCD) spectroscopy. Additionally, the feeding deterrent mechanism was evaluated through RNA sequencing, leading to 105 differentially expressed genes (DEGs), of which 58 were upregulated and 47 were downregulated. Furthermore, quantitative real-time PCR (qRT-PCR) validation was employed to confirm that its synergistic feeding deterrent effects involve disruptions in energy metabolism, neural signaling, immune modulation, detoxification processes, and chitin synthesis. Specifically, qRT-PCR revealed significant upregulation of chitin metabolism-related genes, including chitinase 9 ( TcCht9 ), chitinase 3 ( TcChi-3 ), chitinase 11 ( TcCht11 ), and chitinase 6 ( TcChi-6 ) at 12 h treatment. Moreover, molecular docking revealed the potential docking targets of 6-cadinenedihydrochelerythrine against the four chitinases. Consequently, the findings demonstrated the transcriptomic response of Tribolium castaneum to 6-cadinenedihydrochelerythrinone, elucidated the antifeedant mechanism, and enriched the novel candidate insecticide for Integrated Pest Management. • A novel sesquiterpene alkaloid was isolated from Zanthoxylum piasezkii roots. • The new compound exhibited promising feeding deterrence against Tribolium castaneum . • Insecticidal mechanism was revealed by RNA sequencing with qRT-PCR validation. • The novel compound could be novel alternative insecticide on pests control. • Molecular docking revealed the interaction between the new compound and chitinases.