Structural requirements of organophosphorus insecticides (OPI) to inhibit chicken yolk sac membrane kynurenine formamidase related to OPI teratogenesis

► OPI structural requirements to inhibit kynurenine formamidase investigated by 3D QSAR. ► Enzyme of chicken yolk sac membranes targeted with respect to OPI teratogenesis. ► Electrostatic and steric fields found as best predictors of OPI inhibitory potency. ► Electronegativity around pyrimidinyl nitrogens makes pyrimidinyl OPI best inhibitors. ► Specific structural features that make some OPI superior inhibitors outlined.