松油烯-4-醇光学异构体及外消旋体对家蝇的杀虫活性比较

【目的】比较松油烯-4-醇光学异构体对家蝇 Musca domestica 的熏蒸活性差异，为其光学异构体的应用提供理论依据。【方法】以家蝇4日龄成虫为供试昆虫，采用三角瓶熏蒸法比较测定了松油烯-4-醇光学异构体和外消旋体对其的熏蒸与击倒活性，并测定了松油烯-4-醇光学异构体及外消旋体对家蝇头部Na⁺ , K⁺-ATPase活性的影响。【结果】松油烯-4-醇外消旋体对家蝇的熏蒸活性和击倒活性最强，右旋异构体次之，左旋异构体最差，外消旋体、右旋异构体和左旋异构体对家蝇的致死中浓度（LC₅₀）分别为2.5，2.9和3.7 μL/L；在LC₉₀ 剂量下的击倒中时（KT₅₀）分别为12.6，16.7和18.9 min；松油烯-4-醇光学异构体及外消旋体均可显著抑制Na⁺, K⁺-ATPase的活性，活体条件下，松油烯-4-醇光学异构体及外消旋体对Na⁺, K⁺-ATPase活性的抑制作用随着中毒症状的加剧而增强，具有时间效应，其中左旋异构体的抑制作用最强；离体条件下，松油烯-4-醇光学异构体及外消旋体对Na⁺, K⁺-ATPase活性的抑制作用具有浓度依赖效应，其中外消旋体对Na⁺, K⁺-ATPase活性的抑制能力最强，明显高于同浓度下的右旋异构体和左旋异构体。【结论】松油烯-4-醇的光学异构体对家蝇的杀虫活性存在差异，外消旋体的活性明显高于异构体单体。开发松油烯-4-醇类杀虫剂，应以光学异构体的混合物作为有效成分。

Comparison of the insecticidal activities of terpinen-4-ol optical isomers and racemate against the housefly,Musca domestica

【Aim】 This research aims to evaluate the difference in insecticidal activity among the optical isomers and racemate of terpinen-4-ol against the housefly, Musca domestica, and to provide a guidance for utilization of terpinen-4-ol optical isomers. 【Methods】 The fumigation and knock-down toxicities of the optical isomers and racemate of terpinen-4-ol against 4-day-old adults of M. domestica were detected with the Erlenmeyer flask method, and the effects of these compounds onNa⁺, K⁺-ATPase specific activity in the head were tested. 【Results】 The racemate of terpinen-4-ol showed the highest fumigation and knock down toxicities to M. domestica adults, followed by the dextroisomer and then the laevoisomer. The median lethal concentration (LC₅₀) values of the racemate, dextroisomer and laevoisomer against M. domestica adults were 2.5, 2.9 and 3.7 μL/L, respectively, and the median knock down time (KT₅₀) values in treatment of LC_90were 12.6, 16.7 and 18.9 min, respectively. In vivo, the dextroisomer, laevoisomer and racemate of terpinen-4-ol could significantly inhibit Na⁺, K⁺-ATPase specific activity, and the inhibitory effect showed time effect, viz.the inhibition was enhanced as the symptom exacerbated; moreover, the laevoisomer showed more significantly inhibitory effect onNa⁺, K⁺-ATPase activity than the dextroisomer and racemate. In vitro, terpinen-4-ol inhibited Na⁺, K⁺-ATPase activity with a dose dependent effect, and racemate showed remarkably superior inhibitory effect than the dextroisomer and laevoisomer at the same dose. 【Conclusion】 There exist differences in insecticidal activity of the optical isomers of terpinen-4-ol against M. domestica adults, and the racemate has remarkably superior activity to the optical isomers. Thus, the mixture of the optical isomers of terpinen-4-ol should be adopted as the effective component to develop terpinen-4-ol insecticide.