Simple method to calculate octanol–water partition coefficient of organic compounds

Abstract

Risk of molecular migration in food/packaging system is important consideration from safety, hygienic and economic points of view. Octanol/water system is a good reference for explanation of hydrophobic/hydrophilic character of food/packaging system. In this paper, quantitative structure-property relationships (QSPR) for estimating log P values (octanol/water partition coefficient) were developed based on molecular descriptors using a set of 42 organic compounds (aromas compounds and solvents). In this study, we have attempted to develop a simple method of approximating log P for organic molecules of diverse physical and chemical properties such as molecular size, surface area and hydrophilicity/hydrophobicity. The sets of molecular descriptors were derived from Constitutional and Quantum-chemical descriptors. The correlation coefficient ( r 2) for fitting this training database was 0.941 for 42 molecules and 0.983 for validation using nine other molecules, and the standard deviation of 0.02. The result showed that our methods for log P estimation is applicable to QSPR studies and gives better results than other more complicated methods.