Structure-activity relationships of nicotinoids and imidacloprid analogs

Structure-activity relationships (SAR) of imidacloprid [1-(6-chloro-3-pyridylmethyl)-N-nitro-imidazolidin-2-ylidene amine] and nineteen related compounds studied from their insecticidal activity to the green rice leafhopper and from the binding affinity to the alpha-bungarotoxin (alpha-BGTX) binding site of nicotinic acetylcholine receptor (aAChR) from the honeybee were compared with those of nicotinoids. The results indicated that both groups were closely related in terms of sharing the same binding site, the same essential moiety (3-pyridylmethylamino) and the similar SAR. In nicotinoids, the amino nitrogen atom is highly basic and ionized in the organisms, while the nitrogen atom seems partially positive due to the electron withdrawing neighboring group in the imidacloprid related compounds