Abstract
Multivariate structure-activity relationships of new modeled thirty two antinociceptive active benzothiazolinone derivatives have been investigated by using two different chemometrics methods, principal component analysis (PCA) and hierarchical cluster analysis (HCA), for rating biological activities. Twenty Molecular descriptors, which indicate electronic, termochemical and hydrophobic properties of molecules, are calculated by means of Austin Model (AM1) and density functional theory (DFT). The PCA and HCA methods are applied with polarizability (α), electrophilic index (ω) and heat of formation in aqueous phase (HOFAqueous). The results are found quite efficient to classify the thirty two compounds in two groups to be active and inactive. The correlation matrix and variable weight have used to explain of relationships between calculated physicochemical parameters of molecules. Adding F and OCH3 substituents to main ring of the investigated compounds and lengthening in alkyl group located on piperazine changes the biological activity.