Non-food bioactive products as pesticide candidates: Preparation and agrochemical activities of novel nonivamide ether derivatives containing the isoxazole fragment

Abstract

To explore non-food natural products as pesticide candidates for agricultural application, a series of nonivamide ether derivatives (3a–3q) containing the isoxazole fragment were constructed from an alkaloid nonivamide isolated from Capsicum annuum L. Against Mythimna separata Walker, the final corrected mortality rate (FCMR) of 3b at 1.0 mg/mL was 62.9 %, which was 2.0 times of that of nonivamide. Against Aphis citricola Van der Goot, the median lethal dose (LD50) value of 3d was 0.049 μg/nymph, which was 12.4 times of that of nonivamide. Against Plutella xylostella Linnaeus, the median lethal concentration (LC50) value of compound 3b was 0.793 mg/mL, which was 9.2-fold of that of nonivamide. Furthermore, the enzymes activity changes of carboxylesterase (CarE), glutathione S-transferase (GST), and mixed function oxidase (MFO) over time in P. xylostella treated with 3b were evaluated. We hope that this study will establish a robust groundwork for structural modification of nonivamide derivatives and their potential utilization as plant-based insecticides.