Honda Hideo, Tomizawa Motohiro, Casida John E
Department of Environmental Science, Policy and Management, University of California, Berkeley, California 94720-3112, USA.
J Agric Food Chem. 2006 May 3;54(9):3365-71. doi: 10.1021/jf0601517.
The diversity of neonicotinoid insecticides acting as insect nicotinic acetylcholine (ACh) receptor (nAChR) agonists is illustrated by imidacloprid (IMI) with chloropyridinylmethyl (CPM) and N-nitroimine substituents, dinotefuran (DIN) with tetrahydrofurylmethyl (TFM) and N-nitroimine moieties, and acetamiprid (ACE) with CPM and N-cyanoimine groups. These three neonicotinoids are used here as radioligands to test the hypothesis that they all bind to the same site in the same way in both fruit flies (Drosophila melanogaster) and a leafhopper pest (Homalodisca coagulata): that is, neonicotinoid binding site specificity is conserved in the insect nAChRs. Multiple approaches show that [3H]IMI and [3H]ACE interact with an identical site in both species. However, although [3H]DIN binds with high affinity in both insects, its pharmacological profile in Homalodisca is surprisingly unique, with high sensitivity to some TFM-containing compounds and ACh. The TFM moiety of DIN may bind in a different orientation compared to the CPM group of IMI and ACE.
新烟碱类杀虫剂作为昆虫烟碱型乙酰胆碱（ACh）受体（nAChR）激动剂的多样性体现在：吡虫啉（IMI）带有氯吡啶甲基（CPM）和N-硝基亚胺取代基，啶虫脒（DIN）带有四氢呋喃甲基（TFM）和N-硝基亚胺部分，以及噻虫嗪（ACE）带有CPM和N-氰基亚胺基团。这三种新烟碱类杀虫剂在此用作放射性配体，以检验以下假设：它们在果蝇（黑腹果蝇）和叶蝉害虫（葡萄根瘤蚜）中均以相同方式结合到同一位点，即新烟碱类结合位点特异性在昆虫nAChRs中是保守的。多种方法表明，[3H]IMI和[3H]ACE在两个物种中均与同一位点相互作用。然而，尽管[3H]DIN在两种昆虫中均以高亲和力结合，但其在葡萄根瘤蚜中的药理学特征却出奇地独特，对一些含TFM的化合物和ACh具有高敏感性。与IMI和ACE的CPM基团相比，DIN的TFM部分可能以不同的方向结合。
