Toxicity and Fate of Acetylchromenes in Pest Insects
Toxicity and Fate of Acetylchromenes in Pest Insects
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乙酰色烯对害虫的毒性和归宿
DOI：
10.1021/bk-1989-0387.ch004
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发表时间：
1989
期刊：
影响因子：
--
通讯作者：
M. Isman
中科院分区：
文献类型：
--
作者：
M. Isman
乙酰色烯（苯并吡喃）是沙漠向日葵Encelia的主要天然成分，通过残留接触对广泛的昆虫有毒。在玻璃表面上进行生物测定，主要化合物恩替卡林对斑地老虎（夜蛾科）和迁徙蝗虫（蝗科）的LC 50分别为1.4和11.8 µg/cm 2。结构-活性关系表明，具有游离羟基或饱和杂环的色烯衍生物的毒性明显低于恩替卡林。乙酰色烯局部应用于成年蚱蜢迅速从角质层吸收，代谢产物和母体色烯出现在排泄物中两个小时内的应用。然而，只有20-40%的施用剂量被排泄，其余的不能通过提取昆虫来回收。简单的代谢物是由偕甲基氧化或酮还原产生的。这些代谢物的后续生物测定，无论是残留物接触或局部应用，表明他们是显着低于其母体乙酰色烯的毒性。苯并呋喃是恩塞利亚和其他沙漠植物的密切相关成分，对昆虫无毒。然而，苯并呋喃拮抗的毒性encecalin在三种昆虫测试日期。苯并呋喃优肝素没有干扰前茂III的抗激素作用的马利筋错误。恩替卡林对几种粘虫幼虫具有显著的拒食活性。
Acetylchromenes (benzopyrans), major natural constituents of the desert sunflowerEncelia, are toxic to a wide range of insects via residue contact. Bioassayed on glass surfaces, the predominant compound, encecalin, has LC50s of 1.4 and 11.8 µg/cm2against the variegated cutworm (Noctuidae), and the migratory grasshopper (Acrididae), respectively. Structure-activity relations indicate that chromene derivatives possessing free hydroxyl groups or saturated heterocycles are significantly less toxic than encecalin. Acetylchromenes applied topically to adult grasshoppers are rapidly absorbed from the cuticle, and both metabolites and parent chromenes appear in the excreta within two hours of application. However, only 20-40% of the applied dose is excreted, and the remainder cannot be recovered by extraction of the insect. Simple metabolites result from oxidation of the geminal methyl groups or reduction of the ketone. Subsequent bioassays of these metabolites, either by residue contact or topical application, indicate that they are significantly less toxic than their parent acetylchromenes. Benzofurans, closely related constituents ofEnceliaand other desert plants, are non-toxic to insects. However, benzofurans antagonize the toxicity of encecalin in three species of insects tested to date. The benzofuran euparin did not interfere with the antihormonal action of precocene III in the milkweed bug. Encecalin exhibits substantial antifeedant activity against several species of noctuid caterpillars.