Construction of Cholesterol Oxime Ether Derivatives Containing Isoxazoline/Isoxazole Fragments and Their Agricultural Bioactive Properties/Control Efficiency.

To explore natural-product-based pesticidal candidates and high value-added application of cholesterol in agriculture, oximinoether derivatives of cholesterol-containing isoxazoline/isoxazole fragments ( and ) were semiprepared by structural optimization of cholesterol. Their structures were characterized by optical rotation, high-resolution mass spectrometry (HRMS), IR, and H NMR spectroscopy. Particularly, the configurations of oxime fragments at the C-7 position of target compounds were undoubtedly determined by X-ray crystallography. Against Walker, compounds , , , and showed 2.4-2.7-fold growth inhibitory activity of the precursor cholesterol. Against Linnaeus, compounds -, , and showed 2.4-2.7-fold oral toxicity of cholesterol. Against Van der Goot, compounds and exhibited 4.9 and 5.8-fold aphicidal activity of cholesterol, respectively. Notably, they showed good control effects (3.0-5.0-fold promising control efficiency of ) against in the greenhouse. Structure-activity relationships (SARs) suggested that the C-3 hydroxyl group and the C-7 position of cholesterol are two important modification sites. It will pave the way for future structural optimization and application of cholesterol derivatives as potential pesticidal agents in agriculture.