Quantitative structure—activity studies of some octopaminergic agonists against Periplaneta americana

The quantitative relationship between the structure of 2‐(arylimino) thiazolidines (AITs), arylethanolamines (AEAs) and 2‐(arylalkylamino)‐2‐thi‐azolines (AATs) and their octopamine (OA)‐agonist activities against the ventral nerve cord of American cockroach, Periplaneta americana L., was analysed using reported physicochemical parameters and regression analysis. The electronic nature of a substituent was the most important factor for AAT, followed by the hydrophobic effects: the more electron‐donating and the more hydrophobic the substituent, the greater the activity. The hydrophobic nature of a substituent in AEA was the most important factor, followed by the steric effects: the more hydrophobic the substituent, the greater the activity. The more electron‐donating the substituent of AIT, the greater the activity.