Three-Dimensional Structure-Activity Relationships of Synthetic Pyrethroids: 1. Similarity in Bioactive Conformations and Their Structure-Activity Pattern

The three-dimensional “bioactive” conformations of various types of pyrethroid insecticides were deduced from among optimized conformations which were generated on the basis of the exhaustive conformational exploration of the reference compound, MTI-800. A “folded” rather than an “extended” conformation was proposed to be the “bioactive structure” of pyrethroid molecules included in this study. The folded “bioactive” structures were further analyzed in terms of molecular (dis)similarity indices to elucidate the effect of the “local” structural variations on the activity. The results indicate that the overall bioactive conformation as well as the local 3D similarity of the molecule are important in governing the potency variations in the insecticidal activity.