Molecular modeling study on the structure-activity relationship of substituted dibenzoyl-1-tert-butylhydrazines and their structural similarity to 20-hydroxyecdysone

Several possible three-dimensional conformations of substituted dibenzoyl-1-tert-butylhydrazine (SBH) were established with the help of a molecular modeling method. It was found that there was a good parabolic relationship between larvicidal activity (pLD₅₀ or pLD₅₀ ¹) and the nearest distance r of the oxygen atomic center of carbonyl group A to the atomic center connecting with benzene ring B of substituents in conformation I of SBH. Molecular mechanics calculations revealed that SBH and 20-hydroxyecdysone have several similarities in the π-electronic conjugated area, flexible alkyl group and strong negative electronic center near the conjugated area; therefore, SBH might mimic the binding region of ecdysone.