Quantitative structure–activity relationship study of amide mosquito repellents

A quantitative structure–activity relationship (QSAR) study on 43 amide repellents was carried out by the heuristic method in order to reveal the correlations between molecular parameters of these amides and their repellency against <i>Aedes aegypti</i>. Sketches and optimizations of molecular structures were achieved by the Gaussian software package. Generation and screening of molecular parameters were accomplished using CODESSA 2.7.10 software. The leave-one-out method was applied for the model validation. The results showed that a four-descriptor QSAR model with <i>r</i>² of 0.897 was obtained. The average <i>r</i>² values of the training set and test set of the QSAR model were 0.901 and 0.863, respectively, which suggested that the stability and predictability of the model were confirmed. Analysis of the implications of the descriptors that constitute the QSAR model indicated that all the descriptors were related to the charge distribution over the molecule and affect the dipole moment of the repellents.