QSAR Analysis of Substituted 2‐Phenylhydrazonoacetamides Acting as Inhibitors of 15‐Lipoxygenase

An evaluation of quantitative structure-activity relationships (QSAR) for 28 N1-phenyl-2-phenylhydrazonoacetamides, that are inhibitors of soybean 15-lipoxygenase was carried out with different statistical methods. Initially the variation of structure was characterized by the Free-Wilson method and analyzed by multiple linear regression (MLR) and partial least squares analysis (PLS). Both methods revealed an increase in activity, if the N1-phenyl substituent of the parent molecule is meta-substituted with groups, that show a positive resonance effect at the annular structure. To include physicochemical aspects a combined Free-Wilson-Hansch approach was used. Because of high intercorrelations among some physicochemical parameters a principal component-analysis (PCA) was performed to extract information from those intercorrelated variables in a few principal components (PC's). The resulting equations indicate that besides an electron donating group at the central amidrazone moiety electronic effects at the arylhydrazone substituent play an important role for the biological activity.