Faculty of Biology and Environment Protection, Nicolaus Copernicus University, Toruń, Poland.
Pest Manag Sci. 2014 Jun;70(6):953-8. doi: 10.1002/ps.3634. Epub 2013 Sep 30.
Feeding deterrent activity of synthetic halogen lactones against larvae and adults of the lesser mealworm, Alphitobius diaperinus Panzer, in laboratory choice and no-choice tests was studied. The compounds were synthesised from racemic and enantiomerically enriched (ee = 91-98%) cis- and trans-piperitols, which were obtained from (±)-piperitone.
Structure-activity relationship studies identified several synthetic halolactones with a very strong feeding deterrent activity. The most active were the enantiomeric chlorolactones with chiral centre configurations (1S,4S,5R,6R) and (1R,4R,5S,6S) and their racemic mixture. The racemic bromo- and iodolactones obtained from cis-piperitol and saturated lactones with a chiral centre configuration (1R,4S,6R) were also very good antifeedants in comparison with piperitone. Most of the studied compounds were better antifeedants against adults than against larvae-among the 21 compounds, only one bromolactone with a chiral centre configuration (1S,4R,5R,6R) was a weaker deterrent for adults.
Chemical transformation of the piperitone molecule by the introduction of a lactone function and a halogen atom strongly changed its antifeedant properties against the lesser mealworm. Optimum activity is dependent on the presence of a chlorine atom at C-5 of the cyclohexane ring. The activity of bromo- and iodolactones depended strongly on the chiral centre configuration and the halogen substituent.
研究了合成卤代内酯对小菜蛾幼虫和成虫的拒食活性，这些内酯是从小蒿醇的外消旋体和对映体富集（ee=91-98%）的顺式和反式哌啶醇合成的，而小蒿醇则是从（±）-胡椒酮获得的。
构效关系研究确定了几种具有很强拒食活性的合成卤代内酯。最活跃的是具有手性中心构型（1S,4S,5R,6R）和（1R,4R,5S,6S）的对映体氯内酯及其外消旋混合物。从顺式哌啶醇获得的对映体溴代和碘代内酯以及具有手性中心构型（1R,4S,6R）的饱和内酯也是很好的拒食剂，与胡椒酮相比。大多数研究的化合物对成虫的拒食活性都优于幼虫-在所研究的 21 种化合物中，只有一种具有手性中心构型（1S,4R,5R,6R）的溴代内酯对成虫的拒食活性较弱。
通过引入内酯官能团和卤素原子对胡椒酮分子进行化学转化，强烈改变了其对小菜蛾的拒食活性。最佳活性取决于环己烷环上 C-5 处是否存在氯原子。溴代和碘代内酯的活性强烈依赖于手性中心构型和卤素取代基。
