QSPR modeling of odor threshold of aliphatic alcohols using extended topochemical atom (ETA) indices

Abstract

The present work establishes a quantitative structure-property relationship (QSPR) between topochemical features and odor threshold (OT) of aliphatic alcohols. A data set of 53 aliphatic alcohols was chosen for the analysis employing different chemometric techniques, among which, genetic function approximation with spline option (GFA-spline) showed the most acceptable results in terms of internal and external validation metric values. The extended topochemical atom (ETA) indices, developed by the present authors' group, were considered as descriptors for model development. Additionally, selected non- ETA descriptors were also tried for model development. It was observed that the models with ETA indices significantly surpass the predictive ability of the models developed using other descriptors. The final model suggests that molecular branching and electronic parameters significantly influence the odor potency of the molecules. Additionally, increased lipophilicity and reduced electronegativity increase the odorant property. The model thus developed may effectively be used for prediction of odor threshold of any untested aliphatic alcohols.