title: Semisynthesis of Esters of Fraxinellone C4/10-Oxime and Their Pesticidal Activities.
abstract: A total of 20 esters of fraxinellone C4/10-oxime were synthesized and determined by melting points, optical rotation, infrared spectra, proton nuclear magnetic resonance spectra, and high-resolution mass spectrometry spectra. Two steric configurations of compounds 7i and 8i were unambiguously confirmed by X-ray crystallography. Additionally, their pesticidal activities were assessed on two typical lepidopteran pests, Mythimna separata Walker and Plutella xylostella Linnaeus. Generally, all compounds exhibited less potent oral toxicity than toosendanin against third-instar larvae of P. xylostella. However, all compounds showed the growth inhibitory property against early third-instar larvae of M. separata. Notably, compounds 7m, 8b, 8k, 9, and 11 displayed more potent pesticidal activity than toosendanin. This demonstrated that introducing the C-4 carbonyl or oxime group on fraxinellone resulted in more promising derivatives than those bearing a C-10 carbonyl or oxime substituent.
authors.affiliation: College of Plant Protection, and ‡Shaanxi Key Laboratory of Natural Products & Chemical Biology, Northwest A&F University , Yangling, Shaanxi 712100, People's Republic of China.
authors.forename: Qin
authors.initials: Q
authors.lastname: Li
authors.affiliation: College of Plant Protection, and ‡Shaanxi Key Laboratory of Natural Products & Chemical Biology, Northwest A&F University , Yangling, Shaanxi 712100, People's Republic of China.
authors.forename: Xiaobo
authors.initials: X
authors.lastname: Huang
authors.affiliation: College of Plant Protection, and ‡Shaanxi Key Laboratory of Natural Products & Chemical Biology, Northwest A&F University , Yangling, Shaanxi 712100, People's Republic of China.
authors.forename: Shaochen
authors.initials: S
authors.lastname: Li
authors.affiliation: College of Plant Protection, and ‡Shaanxi Key Laboratory of Natural Products & Chemical Biology, Northwest A&F University , Yangling, Shaanxi 712100, People's Republic of China.
authors.forename: Jingchun
authors.initials: J
authors.lastname: Ma
authors.affiliation: College of Plant Protection, and ‡Shaanxi Key Laboratory of Natural Products & Chemical Biology, Northwest A&F University , Yangling, Shaanxi 712100, People's Republic of China.
authors.forename: Min
authors.initials: M
authors.lastname: Lv
authors.affiliation: College of Plant Protection, and ‡Shaanxi Key Laboratory of Natural Products & Chemical Biology, Northwest A&F University , Yangling, Shaanxi 712100, People's Republic of China.
authors.forename: Hui
authors.initials: H
authors.lastname: Xu
mesh_terms: D000818:Animals; D001572:Benzofurans / Q000737:chemistry* / Q000494:pharmacology; D018360:Crystallography, X-Ray; D004952:Esters / Q000737:chemistry* / Q000494:pharmacology; D007306:Insecticides / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology*; D007814:Larva / Q000187:drug effects; D015394:Molecular Structure; D009036:Moths / Q000187:drug effects; D010091:Oximes / Q000737:chemistry* / Q000494:pharmacology
chemical_list: D001572:Benzofurans; D004952:Esters; D007306:Insecticides; D010091:Oximes; C075391:fraxinellone
keywords: Mythimna separata Walker; Plutella xylostella Linnaeus; fraxinellone; natural-product-based insecticide; pesticidal activity; structural modification