title: Feeding deterrents against two grain storage insects from Euphorbia fischeriana.
abstract: The screening of several Chinese medicinal herbs for insecticidal principles showed that Euphorbia fischeriana roots possessed significant feeding deterrent activity against two stored-product insects (Tribolium castaneum and Sitophilus zeamais). From ethanol extract, four feeding deterrents were isolated by bioassay-guided fractionation. The compounds were identified as jolkinolide B, 12-deoxyphorbol 13-(9Z)-octadecenoate 20-acetate, 17-hydroxyjolkinolide A and B on the basis of their phytochemical and spectral data. Jolkinolide B and 17-hydroxyjolkinolide B possessed strong feeding deterrent activities against S. zeamais (EC₅₀ = 342.1 and 543.9 ppm, respectively) and T. castaneum adults (E₅₀ = 361.4 and 551.5 ppm, respectively). 17-Hydroxyjolkinolide A and 12-deoxyphorbol 13-(9Z)-octadecenoate 20-acetate A also exhibited feeding deterrent activity against the two grain storage insects with EC₅₀ values of 631.9 and 884.3 ppm for S. zeamais and 656.5 and 1058.4 ppm for T. castaneum adults.
authors.affiliation: Analytical and Testing Center, Beijing Normal University, Beijing 100875, China.
authors.forename: Zhu Feng
authors.initials: ZF
authors.lastname: Geng
authors.forename: Zhi Long
authors.initials: ZL
authors.lastname: Liu
authors.forename: Cheng Fang
authors.initials: CF
authors.lastname: Wang
authors.forename: Qi Zhi
authors.initials: QZ
authors.lastname: Liu
authors.forename: Sheng Min
authors.initials: SM
authors.lastname: Shen
authors.forename: Zi Mu
authors.initials: ZM
authors.lastname: Liu
authors.forename: Shu Shan
authors.initials: SS
authors.lastname: Du
authors.forename: Zhi Wei
authors.initials: ZW
authors.lastname: Deng
mesh_terms: D000818:Animals; D001517:Coleoptera / Q000502:physiology*; D004224:Diterpenes / Q000737:chemistry / Q000494:pharmacology*; D028481:Euphorbia / Q000469:parasitology*; D005247:Feeding Behavior / Q000187:drug effects*; D009682:Magnetic Resonance Spectroscopy; D015394:Molecular Structure; D010575:Pesticides / Q000737:chemistry / Q000494:pharmacology*
chemical_list: D004224:Diterpenes; D010575:Pesticides