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Chiral pesticides: identification, description, and environmental implications
Elin M Ulrich1, Candice N Morrison, Michael R Goldsmith
1U.S. Environmental Protection Agency, Research Triangle Park, NC 27711, USA. ulrich.elin@epa.gov
Reviews of Environmental Contamination and Toxicology
|February 22, 2012
Summary
This study reviewed 1,693 pesticides, finding 482 are chiral. Understanding pesticide chirality is crucial for assessing environmental fate, toxicity, and efficacy, as stereoisomers can differ significantly.
Area of Science:
- Environmental Chemistry
- Agrochemical Science
- Stereochemistry
Background:
- A comprehensive review of 1,693 pesticides was conducted, encompassing organic, inorganic, and biologically derived compounds.
- The study identified that 482 (28%) of these pesticides are chiral, with 30% of organic pesticides exhibiting chirality.
- Pesticide chirality presents significant challenges in synthesis, analysis, environmental monitoring, and risk assessment due to potential variations in efficacy and toxicity among stereoisomers.
Purpose of the Study:
- To analyze the prevalence of chirality in a broad spectrum of pesticides.
- To categorize chiral pesticides by their pesticidal utilities (e.g., insecticides, herbicides, fungicides).
- To highlight the need for further research and development in enantioselective chromatographic methods for chiral pesticide analysis.
Main Methods:
- A dataset of 1,693 pesticides was compiled from the Pesticide Manual and the Compendium of Common Pesticide Names.
- Pesticides were classified by chemical type, pesticidal utility, and the presence and number of chiral centers.
- ChirBase database records for enantioselective separations were analyzed, covering 30% of the identified chiral pesticides.
Main Results:
- Out of 1,693 reviewed pesticides, 482 (28%) are chiral. Of these, 195 are insecticides, 150 are herbicides, and 104 are fungicides.
- Chiral pesticides exhibit varying numbers of chiral features, with 56% having one chiral center.
- Only 30% of the chiral pesticides in the review have associated enantioselective separation records in the ChirBase database.
Conclusions:
- The prevalence of chirality in pesticides necessitates a deeper understanding of stereoisomer-specific properties.
- Current analytical methods, particularly enantioselective chromatography, require expansion to cover a larger proportion of chiral pesticides.
- The public availability of the generated dataset aims to facilitate tools for handling molecular asymmetry in agrochemicals, improving risk and fate assessments.
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