title: Components and insecticidal activity against the maize weevils of Zanthoxylum schinifolium fruits and leaves.
abstract: In our screening program for new agrochemicals from Chinese medicinal herbs and wild plants, Zanthoxylum schinifolium essential oils were found to possess strong insecticidal activity against the maize weevil Sitophilus zeamais. The essential oils of Z. schinifolium fruits and leaves were extracted via hydrodistillation and investigated by GC and GC-MS. Estragole (69.52%) was the major compound of the essential oil of fresh fruits, followed by linalool (8.63%) and limonene (4.34%) and 94.33% of the total components were monoterpenoids. The main components of the essential oil of fresh leaves were linalool (12.94%), ar-tumerone (8.95%), limonene (6.45%) and elixene (5.43%) and only 50.62% were monoterpenoids. However, the essential oil from purchased fruits contained linalool (33.42%), limonene (13.66%) and sabinene (5.72%), followed by estragole (4.67%), nerol (4.56%) and 4-terpineol (4.27%). Estragole, linalool and sabinene were separated and purified by silica gel column chromatography and preparative thin layer chromatography, and further identified by means of physicochemical and spectrometric analysis. The essential oil from the fresh fruits (LD₅₀ = 15.93 μg/adult) possessed two times more toxicity to the insects compared with that of fresh leaves (LD₅₀ = 35.31 μg/adult). Estragole, linalool and sabinene exhibited contact activity against S. zeamais with LD₅₀ values of 17.63, 13.90 and 23.98 μg/adult, respectively. The essential oils of Z. schinifolium possessed strong fumigant toxicity against S. zeamais adults with LC₅₀ values of 13.19 mg/L (fresh fruits), 24.04 mg/L (fresh leaves) and 17.63 mg/L (purchased fruits). Estragole, linalool and sabinene also exhibited strong fumigant toxicity against the maize weevils with LC₅₀ values of 14.10, 10.46 and 9.12 mg/L, respectively.
authors.affiliation: State Key Laboratory of Earth Surface Processes and Resource Ecology, Beijing Normal University, Beijing 100875, China.
authors.forename: Cheng Fang
authors.initials: CF
authors.lastname: Wang
authors.forename: Kai
authors.initials: K
authors.lastname: Yang
authors.forename: Hai Ming
authors.initials: HM
authors.lastname: Zhang
authors.forename: Jie
authors.initials: J
authors.lastname: Cao
authors.forename: Rui
authors.initials: R
authors.lastname: Fang
authors.forename: Zhi Long
authors.initials: ZL
authors.lastname: Liu
authors.forename: Shu Shan
authors.initials: SS
authors.lastname: Du
authors.forename: Yong Yan
authors.initials: YY
authors.lastname: Wang
authors.forename: Zhi Wei
authors.initials: ZW
authors.lastname: Deng
authors.forename: Ligang
authors.initials: L
authors.lastname: Zhou
mesh_terms: D000818:Animals; D002850:Chromatography, Gel; D008401:Gas Chromatography-Mass Spectrometry; D007306:Insecticides; D007928:Lethal Dose 50; D009682:Magnetic Resonance Spectroscopy; D009822:Oils, Volatile / Q000494:pharmacology*; D018515:Plant Leaves / Q000737:chemistry*; D048889:Weevils; D032106:Zanthoxylum / Q000737:chemistry*
chemical_list: D007306:Insecticides; D009822:Oils, Volatile