ABSTRACT
Based on experimental data for the octanol-water partition coefficient (Kow) of 21 polychlorinated naphthalenes (PCNs) congeners, two types of three-dimensional QSAR (3D-QSAR) models —comparative molecular field analysis (CoMFA) and comparative molecular similarity indices analysis (CoMSIA) —were established with Sybyl software. This was established to predict the Kow values of 54 additional PCN congeners and carry out a modification of CN-73 to lower its Kow significantly, simultaneously maintaining the stability and insulativity of CN-73. The contour maps of two models showed that the electrostatic field plays a dominating role in the logKow values of PCNs, and the bioconcentration of PCN decreased when -Cl atoms on the 1-, 3-, 4-, 6-, and 7-positions of PCNs were replaced with electropositive groups. Moreover, there was a positive correlation between the number of -Cl atoms on PCNs and the average logKow values of PCNs. After modification of CN-73 through the electrostatic contour maps, six types of new modified CN-73 compounds were obtained with logKow values two orders of magnitude lower than that of CN-73. Meanwhile, there was not a significant difference observed between the calculated total energy (representing stability) and energy gap (representing insulativity) of the new modified compounds when compared with those of CN-73.
Funding
The research was supported by the Fundamental Research Funds for the Central Universities in 2013 (JB2013146) and the Key Projects in the National Science and Technology Pillar Program in the Eleventh Five-Year Plan Period (2008BAC43B01).