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Enzymatic Synthesis of Epoxidized Metabolites of Docosahexaenoic, Eicosapentaenoic, and Arachidonic Acids
Published on: June 28, 2019
Absolute configuration of 7-epi-sesquithujene
Ashot Khrimian1, Allard A Cossé, Damon J Crook
1Beltsville Agricultural Research Center, Agricultural Research Service, United States Department of Agriculture, Bldg. 007, Rm. 326, BARC-West, 10300 Baltimore Avenue, Beltsville, Maryland 20705, USA. khrimian@ars.usda.gov
Journal of Natural Products
|May 18, 2011
Summary
The absolute configuration of 7-epi-sesquithujene, a compound that attracts emerald ash borers, was determined to be 2S,6S,7R. This finding is crucial for developing effective synthetic lures for pest management.
Area of Science:
- Organic Chemistry
- Forest Entomology
- Natural Products Chemistry
Background:
- 7-epi-sesquithujene is a bicyclic sesquiterpene found in Phoebe porosa oil and produced by stressed ash trees.
- This compound elicits strong electrophysiological responses in the emerald ash borer (Agrilus planipennis).
- The absolute configuration of 7-epi-sesquithujene was previously undetermined, hindering synthetic lure development.
Purpose of the Study:
- To determine the absolute configuration of 7-epi-sesquithujene.
- To establish a method for synthesizing and analyzing stereoisomers of sesquithujene.
- To support the development of a synthetic lure for emerald ash borer management.
Main Methods:
- Isolation of >95% pure 7-epi-sesquithujene from phoebe oil using chromatography.
- Synthesis of sesquithujene stereoisomers.
- Development of a chiral gas chromatography (GC) method for stereoisomer separation.
- Analysis of specific optical rotation and comparison with synthetic standards.
Main Results:
- The specific optical rotation of isolated 7-epi-sesquithujene matched that of a synthetic product with a known configuration.
- A chiral GC method successfully separated all four sesquithujene stereoisomers.
- The absolute configuration of 7-epi-sesquithujene from phoebe oil and white ash was identified as 2S,6S,7R.
Conclusions:
- The absolute configuration of 7-epi-sesquithujene has been definitively established as 2S,6S,7R.
- This determination provides essential information for the synthesis of effective emerald ash borer lures.
- The developed methods enable the characterization and separation of sesquithujene stereoisomers for future research.
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