|Ho, Hsiao-yung - Academia Sinica|
|Aldrich, Jeffrey - University Of California|
|Siegler, Maxime - Johns Hopkins University|
Submitted to: Journal of Natural Products
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/16/2014
Publication Date: 6/18/2014
Publication URL: http://handle.nal.usda.gov/10113/58966
Citation: Khrimian, A., Zhang, A., Weber, D.C., Ho, H., Aldrich, J., Vermillion, K., Siegler, M., Shirali, S., Guzman, F., Leskey, T.C. 2014. Discovery of the Aggregation Pheromone of the Brown Marmorated Stink Bug (Halyomorpha halys) through the Creation of Stereoisomeric Libraries of 1-Bisabolen-3-ols. Journal of Natural Products. 77:1708-1717.
Interpretive Summary: Insect pests cause significant damage to crops and forests, and monitoring their populations aids greatly in reducing pesticide use and biological control. Pheromones, or chemicals that trigger a natural behavioral response in another member of the same species, are commonly used as baits for sampling insect populations. Detailed structures of pheromones of several key stink bug species had not been determined because the methods to make the specific arrangements of their chemical structural elements had not been developed. These included the economically important brown marmorated stink bug for which a pheromone was sought for use in integrated pest management programs. Here, we describe syntheses of all molecules of certain organic chemicals that are made of the same atoms, connected in the same sequence, but the atoms are positioned differently in space. Building these molecular libraries was the key for identifying the exact structures of two main aggregation pheromone components of the brown marmorated stink bug, one of the most destructive pests of fruit vegetable and field crops that recently invaded North America and Europe. These pheromone components were produced by male brown marmorated stink bugs and attracted males, females, as well as immature bugs. The results of this study are of interest to other chemists and entomologist involved in the research of potential pest control compounds, and to State and Federal agencies involved in monitoring and controlling insect pests of agriculture and forest.
Technical Abstract: The rhodium-catalyzed asymmetric addition of trimethylaluminum to diastereomeric mixtures of 1,10-bisaboladien-3-ones 1 and 2 provided a straightforward and novel route to all eight stereoisomers of 1,10-bisaboladien-3-ol and six of the sixteen stereoisomers of 10,11-epoxy-1-bisabolen-3-ol. Relative and absolute configurations were assigned using X-ray crystallography and chemical correlations. Two of these compounds, (3S,6S,7R,10S)-10,11-epoxy-1-bisabolen-3-ol (3) and (3R,6S,7R,10S)-10,11-epoxy-1-bisabolen-3-ol (4), were identified as the main components of a male-produced aggregation pheromone of the brown marmorated stink bug, Halyomorpha halys. Synthetic epoxides 3 and 4 matched the two main compounds in extracts of volatiles collected from males, using GC analysis on enantioselective columns. Each compound attracted female, male, and nymphal H. halys in field trials, with the mixture at the naturally occurring 3.5:1 ratio being more attractive than either compound alone. Moreover, mixtures of stereoisomers containing epoxides 3 and 4 was also attractive to H. halys signifying that the presence of additional stereoisomers did not hinder attraction of H. halys and relatively inexpensive mixtures can be used in monitoring, as well as control strategies. Halyomorpha halys is an invasive species that causes severe injury to fruit, vegetables, and field crops, and is a serious nuisance pest when overwintering aggregations form in homes and businesses. In addition to enabling the complete stereochemical identification of the H. halys main pheromone components, creating stereoisomeric libraries of 1,10-bisaboladien-3-ols and 10,11-epoxy-1-bisabolen-3-ols will be useful in identifying the relative and absolute configurations of the pheromones of at least two other pentatomid bugs, Murgantia histrionica and Tibraca limbativentris.