Synthetic Pogostone Analogs Show Potential for Biorenewable Insect Control

Achievement date: 
2017
Outcome/accomplishment: 

Using triacetic acid lactone (TAL) as the starting molecule, a range of biorenewable molecules were successfully synthesized by researchers at the NSF-funded Engineering Research Center (ERC) for Biorenewable Chemicals (CBiRC) at Iowa State University (ISU) in sufficient quantities to allow for testing in insecticidal applications. Among the synthesized compounds was the known secondary metabolite pogostone, a chemical traditionally isolated from patchouli leaves, which shows promise as an alternative insect repellent.

Impact/benefits: 

The insect control industry is currently based on natural pyrethrins –a class of organic compounds that targets the nervous systems of insects and their derivatives –with no “new” molecules being introduced for the past two decades. This situation has made some insects tolerant to existing insect control products.

In contrast, the compounds identified from the CBiRC set of synthesized molecules have shown better insecticidal activity for houseflies and German cockroaches than natural pyrethrins. Additionally, the pogostone analog was found to provide better mosquito repellency than diethyl-meta-toluamide, better known as DEET. Initial results demonstrate the potential of a pogostone analog in combating the Aedes aegypti (Zika) mosquito.

Explanation/Background: 

The use of TAL derivatives to create improved functional performance over existing petrochemicals in end use applications dramatically changes the economic potential of the TAL platform. Moreover, the ability to transition from commodity-based chemicals to value-added chemicals demonstrates the power of the integrated biology/chemical conversion that is at the heart of the CBiRC technology paradigm. CBiRC researchers have previously demonstrated the ability to convert TAL into a broad range of chemicals including commodities such as sorbic acid. When the team discovered a reference suggesting that pogostone had larvicidal activity, Professor Joel Coats, a nationally known entomologist at ISU, agreed to test a set of pogostone analogs for a range of insects. To CBiRC’s knowledge, these molecules had never before been generated and screened for their insecticidal activity.