Molecular markers for pyrethrin autoxidation in stored pyrethrum crop: analysis and structure determination

Jamie A. Freemont, Stuart W Littler, Oliver E Hutt, Stephanie Mauger, Adam G Meyer, David Winkler, Maurice G. Kerr, John H. Ryan, Helen F. Cole, Peter J Duggan

Research output: Contribution to journalArticleResearchpeer-review

5 Citations (Scopus)

Abstract

Pyrethrum is a natural insecticide extracted from Tanacetum cinerariifolium. Six esters, the pyrethrins, are responsible for the extract's insecticidal activity. The oxidative degradation of pyrethrins through contact with aerial oxygen is a potential cause of pyrethrin losses during pyrethrum manufacture. Described here is the first investigation of the autoxidation chemistry of the six pyrethrin esters isolated from pyrethrum. It was found that pyrethrins I and II, the major pyrethrin esters present in pyrethrum, undergo autoxidation more readily than the minor pyrethrin esters, the jasmolins and cinerins. Chromatographic analysis of pyrethrin I and II autoxidation mixtures showed some correlation with a similar analysis performed on extracts from T. cinerariifolium crop, which had been stored for 12 weeks without added antioxidants. Two pyrethrin II autoxidation products were isolated, characterized, and shown to be present in extracts of stored T. cinerariifolium crop, confirming that autoxidation of pyrethrin esters does occur during crop storage.

Original languageEnglish
Pages (from-to)7134-7141
Number of pages8
JournalJournal of Agricultural and Food Chemistry
Volume64
Issue number38
DOIs
Publication statusPublished - 28 Sep 2016
Externally publishedYes

Keywords

  • autoxidation
  • degradation
  • pyrethrins
  • pyrethrum
  • Tanacetum cinerariifolium

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