Application of TLSER method in predicting the aqueous solubility and noctanol／water partition coefficient of PCBs, PCDDs and PCDFs

The theoretical linear solvation energy relationship(TLSER) approach was adopted to predict the aqueous solubility and noctanol/water partition coefficient of three groups of environmentally important chemicals-polychlodnated biphenyls( PCBs), polychlorinated dibenzodioxins and dibenzofurans( PCDDs and PCDFs). For each compound, five quantum parameters were calculated using AMI semiempidcal molecular orbital methods and used as structure descriptors: average molecular polarizability (α), energy of the lowest unoccupied molecular orbit( ELUMO), energy of the highest occupied molecular orbit( EHOMO ), the most positive charge on a hydrogen atom( q. ), and the most negative atomic partial charge( q- ) in the solute molecule. Then standard independent variables in TLSER equation was extracted and two series of quantitative equations between these quantum parameters and aqueous solubility and n-octanol/water partition coefficient were obtained by stepwise multiple linear regression(MLR) method. The developed equations have both quite high accuracy and explicit meanings. And the cross-validation test illustrated the good predictive power and stability of the established models.The results showed that TLSER could be used as a promising approach in the estimation of partition and solubility properties of macromolecular chemicals, such as persistent organic pollutants.