Quantitative structure-activity relationships of imidacloprid and its analogs with substituents at the C5 position on the pyridine ring in the neuroblocking activity

Abstract

Two nerve activities of imidacloprid analogs with various substituents at the 5-position of the pyridine ring were measured: the conduction blockage in the excised central nerve cord of the American cockroach, and the binding inhibition of a radioligand, [3H]imidacloprid, to the membrane preparation of housefly-head homogenates. Neuroblocking activity was quantitatively analyzed using physicochemical substituent parameters. The greater the electron-releasing resonance effect, the higher the activity. The introduction of sizable and alkoxy substituents was unfavorable. The nerve-binding activity of the tested compounds was linearly related to the neuroblocking activity with one exception. The higher the binding activity, the higher the blocking activity. © Pesticide Science Society of Japan