QSAR for the cytotoxicity of 2-alkyl or 2,6-dialkyl, 4-X-phenols: the nature of the radical reaction

Abstract

In a continuation of studies on the radical mediated toxicity of phenols to leukemia cells, a set of di- and tri- substituted phenols with mostly alkyl substituents in the ortho position were examined. These analogs are similar in structure to the commercial antioxidants BHA and BHT. A QSAR analysis of their growth inhibitory constants led to the formulation of this simple but unusual equation based on 18 congeners:E_S-2 is the Taft steric parameter for the larger of the two ortho substituents while E_R is Otsu's radical parameter, which was originally defined to correlate radical reactions.