Studies On Quantitative Structure Activity Relationships(QSAR) Of Neonicotinoid Insecticides

In this study,32 neonicotinoid compounds were studied on QSAR,Then QSAR model was established,with B3LYP/6-31G(d).On molecular-electronic level,the mechanism was deeply studied in quantum chemistry,molecular mechanic and stati-sticcal analysis methods.Our conclusions are as follows:1 Two neonicotinoid compounds were optimized by using various methods and groups.From the bond angle,bond length,dihedral angle,molecular energy to CPU time etal,the theoretical conformation of two neonicotinoid compounds was compared with their crystal structures.The study shows that B3LYP/6-31G(d) is the scientific and reliable method to optimize neonicotinoid compounds.2 It's the first time that the 32 neonicotinoid compounds have been optimized on B3LYP/6-31G(d) level,12 QSAR parameters were selected by the PCA minimalism finally.QSAR model was established with PCR and PLS,and were carried out in LOO.The result shows that PLS-QSAR model is fitting to a high-forecasting capability and the ideal model can be used to predict the biological activity of neonicotinoid insecticides.3 The four key parameters were analysised,They are LogP,Q_O1O2(or QN₃), BL_N1N2 and(dihedral angle 2) in the PLS-QSAR model.The result shows there is strong negative linear relationship between neonicotinoid compounds' activity and their LogP value.smaller LogP value,higher activity.It provides a quantitative basis for the transformation of the structure and the study on mechanism.4 On molecular-electronic level,it is the first time that two theoretical binding models of neonicotinoid insecticides have been explaind in B3LYP/6-31G(d),which was reported by the newst study.The result shows that Kagabu's model is more scientific and credibile.