Microbial Hydrolysis of Racemic β-Aryl-γ-ethylidene-γ-lactones and Antifeedant Activity of the Products against Alphitobius diaperinus Panzer

Molecules. 2018 Jun 23;23(7):1516. doi: 10.3390/molecules23071516.


Hydrolysis of (±)-β-aryl-γ-ethylidene-γ-lactones by fungal strain Aspergillus ochraceus AM370 afforded (−)-(S)-γ-ethylidene-γ-lactones 2ad and (+)-(R)-γ-ketoacids 3ad. Enantiomeric purity of the unreacted lactones was strictly related to a size of an aryl substituent at C-4 of γ-lactone ring, with the highest ee (77%) obtained for the (−)-(S)-γ-ethylidene-γ-lactone possessing unsubstituted benzene ring (2a) and the lowest one (15%) determined for the (−)-(S)-γ-ethylidene-γ-lactone with bulky 1,3-benzodioxole system (2d). Lactones 2ad, both racemic and enantiomerically enriched, as well as products of their hydrolysis showed varying degrees of feeding deterrent activity against lesser mealworm, Alphitobius diaperinus Panzer, which depended on the structure of the compound and the developmental stage of the lesser mealworm. In the case of adults, more active were γ-lactones 2ad, compared with ketoacids 3ad. Only in the case of lactone 2a was the effect of configuration of stereogenic center on the activity found. Particularly strong deterrents against this stage (T > 180) were racemic and (−)-(S)-γ-ethylidene-γ-lactone with p-methoxysubstituted phenyl ring (2c).

Keywords: antifeedant activity; kinetic resolution; microbial hydrolysis; unsaturated lactones.

MeSH terms

  • Animals
  • Aspergillus / chemistry
  • Aspergillus / enzymology*
  • Biotransformation
  • Feeding Behavior / drug effects*
  • Hydrolysis
  • Insect Repellents / chemistry
  • Insect Repellents / pharmacology*
  • Kinetics
  • Lactones / chemistry
  • Lactones / pharmacology*
  • Stereoisomerism
  • Tenebrio / drug effects*
  • Tenebrio / physiology


  • Insect Repellents
  • Lactones