Sustainable Natural Resources for Aphid Management: β-Ionone and Its Derivatives as Promising Ecofriendly...

β-Ionone, sustainably derived from Petunia hybrida as a natural bioresource, was identified as a lead compound for integrated aphid management. A series of β-ionone derivatives containing ester groups were designed and synthesized for the purpose of discovering renewable botanical-based products. The odorant-binding protein (OBP) binding test indicated that β-ionone and its derivatives displayed binding affinities with Acyrthosiphon pisum OBP9 (ApisOBP9) and Harmonia axyridis OBP15 (HaxyOBP15). Bioactivity assays revealed that most β-ionone derivatives exhibited a higher repellent activity than that of β-ionone. β-Ionone and derivatives 4g and 4l displayed attractiveness to H. axyridis. Specifically, 4g was a highly promising derivative, possessing good repellent activity against A. pisum and attractiveness to H. axyridis. Molecular dynamics simulations revealed that integrating the hydrophobic ester group into the β-ionone framework strengthened the van der Waals interactions of 4g with ApisOBP9/HaxyOBP15, improving the binding affinity with OBPs and producing higher push-pull activity than β-ionone; 4g also had low toxicity toward nontarget organisms. Thus, 4g is a potential ecofriendly, botanical-based option for aphid management.