The natural extract pyrethrum is an insecticidal oil derived from Tanacetum cinerariifolium that is commonly used in domestic and agricultural pesticides. The major constituents of the extract are the Pyrethrins, six esters that provide pyrethrum with its insecticidal properties. These Pyrethrins readily degrade through several environmental means and as such, there can be significant Pyrethrin losses during processing and long-term storage of pyrethrum-based insecticides. This work attempts to alleviate the effect of these degradative processes through the pursuit of stabilised Pyrethrins by chemically removing oxidatively sensitive functionality. Several reduced Pyrethrin analogues were produced and a method to convert the more sensitive Pyrethrins present in the pyrethrum concentrate into their respective more stable jasmolin counterparts, as a mixture with the over-reduced tetrahydropyrethrins, was developed. All other reduction processes abolished insecticidal activity against Lucilia cuprina larvae, whereas some isomerised analogues showed comparable potency with the individual natural pyrethrin esters. This work has revealed new insights into the structure–activity relationships in this unique class of insecticide.

天然提取物除虫菊是从艾叶艾那草提取的杀虫油。广泛用于家庭和农业农药。提取物的主要成分是菊酯，这是一种六酯，可为除虫菊提供杀虫特性。这些除虫菊酯很容易通过几种环境手段降解，因此，在除虫菊基杀虫剂的加工和长期储存过程中，除虫菊酯会大量损失。这项工作试图通过化学去除氧化敏感性官能团来追求稳定的菊酯来减轻这些降解过程的影响。产生了几种还原的除虫菊酯类似物，并开发了一种方法，可以将除虫菊浓缩物中存在的更敏感的除虫菊酯与过量还原的四氢菊酯混合，将其转变为各自更稳定的茉莉素对应物。Lucilia cuprina幼虫，而一些异构化的类似物显示与单个天然除虫菊酯可比的效力。这项工作揭示了这一独特杀虫剂类中的结构-活性关系的新见解。