Predicting mosquito repellent potency of N,N-diethyl-m-toluamide (DEET) analogs from molecular electronic properties

Specific molecular electronic properties of 30 N,N-diethyl-m-toluamide (DEET) analogs demonstrate functional dependence with their reported duration of protection against mosquito bites, thus providing predictors of insect repellent efficacy. No single electronic property is sufficient to predict repellent efficacy as measured by protection time, rather a set of specific electronic properties is required. Thus, the values of the van der Waals surface electrostatic potential by the amide nitrogen and oxygen atoms, the atomic charge at the amide nitrogen atom, and the dipole moment must all be in optimal ranges for potent repellency. The electronic properties were calculated using the AM semi-empirical quantum chemical method using commercial software. These easily calculable predictors of repellent efficacy should be useful in predicting the relative efficacy of newly designed compounds, thus guiding the selection of new repellents for testing.