title: Structure-related antifeedant activity of halolactones with a p-menthane system against the lesser mealworm, Alphitobius diaperinus Panzer.
abstract: BACKGROUND
  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.
  
  
  RESULTS
  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.
  
  
  CONCLUSIONS
  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.
authors.affiliation: Faculty of Biology and Environment Protection, Nicolaus Copernicus University, Toruń, Poland.
authors.forename: Maryla
authors.initials: M
authors.lastname: Szczepanik
authors.forename: Aleksandra
authors.initials: A
authors.lastname: Grudniewska
authors.forename: Beata
authors.initials: B
authors.lastname: Zawitowska
authors.forename: Czesław
authors.initials: C
authors.lastname: Wawrzeńczyk
mesh_terms: D000818:Animals; D001517:Coleoptera / Q000187:drug effects*; D000081005:Cyclohexane Monoterpenes; D007306:Insecticides / Q000737:chemistry / Q000633:toxicity; D007783:Lactones / Q000737:chemistry* / Q000633:toxicity*; D007814:Larva / Q000187:drug effects*; D039821:Monoterpenes / Q000737:chemistry; D013329:Structure-Activity Relationship
chemical_list: D000081005:Cyclohexane Monoterpenes; D007306:Insecticides; D007783:Lactones; D039821:Monoterpenes; C496656:piperitone
keywords: Alphitobius diaperinus; antifeedants; halolactones; lesser mealworm; p-menthane lactones; piperitone