Effects of substituent position on the interactions between PBDEs/PCBs and DOM  

作　　者：NUERLA AiLiJiang QIAO XianLiang LI Jing ZHAO DongMei YANG XianHai XIE Qing CHEN JingWen 

机构地区：[1]Key Laboratory of Industrial Ecology and Environmental Engineering of Ministry of Chemistry, School of Environmental Science and Technology, Dalian University of Technology

出　　处：《Chinese Science Bulletin》2013年第8期884-889,共6页

基　　金：supported by the National Natural Science Foundation of China (21137001, 21077016);the National High Technology Research and Development Program of China (2012AA06A301)

摘　　要：Dissolved organic matters (DOM) have important influence on the environmental behavior and fate of organic pollutants, therefore rationalization of interaction mechanisms between pollutants and DOM has become a hot topic in the field of environmental studies. In this paper, polybrominated diphenyl ethers (PBDEs) and polychlorinated biphenyls (PCBs), widely detected pollutants, were chosen as target compounds. The effects of substituent position on the interaction between PBDEs/PCBs and DOM were explored. Equilibrium dialysis technique combined with quantum chemistry and molecular docking calculations were employed to reveal the interaction mechanism from the view of charge distribution and molecular conformation. It is shown that non-ortho-substituted isomers have larger volumes and stronger hydrophobicity than those of ortho-substituted, therefore non-ortho-substituted isomers bind more favorably with DOM by hydrophobic partition. By calculating the atomic charge distribution of target chemicals and Leonardite humic acid (LHA) molecular model, π-πinteractions between the aromatic rings of target chemicals with LHA are proposed and further proved in molecular docking calculations. There were 10, 8, 6 docking conformations demonstrating π-πinteraction with LHA for CB-77, BDE-77 and BDE-47, respectively, but none was found for CB-47. By comparing the change of dihedral angle of the aromatic rings and energy barrier, non-ortho-substituted PBDEs/PCBs have larger dihedral angle adjustment space and flexibility, which results in stronger interaction and binding capability with DOM than ortho-substituted isomers. This paper shed some lights on the effect of substituent position on the environmental behaviors of PBDEs and PCBs.Dissolved organic matters （DOM） have important influence on the environmental behavior and fate of organic pollutants, there- fore rationalization of interaction mechanisms between pollutants and DOM has become a hot topic in the field of environmental studies. In this paper, polybrominated diphenyl ethers （PBDEs） and polychlorinated biphenyls （PCBs）, widely detected pollutants, were chosen as target compounds. The effects of substituent position on the interaction between PBDEs/PCBs and DOM were explored. Equilibrium dialysis technique combined with quantum chemistry and molecular docking calculations were employed to reveal the interaction mechanism from the view of charge distribution and molecular conformation. It is shown that non-ortho-substituted isomers have larger volumes and stronger hydrophobicity than those of ortho-substituted, therefore non-ortho-substituted isomers bind more favorably with DOM by hydrophobic partition. By calculating the atomic charge distribution of target chemicals and Leonardite humic acid （LHA） molecular model, π-π interactions between the aromatic rings of target chemicals with LHA are proposed and further proved in molecular docking calculations. There were 10, 8, 6 docking conformations demonstrating π-π interaction with LHA for CB-77, BDE-77 and BDE-47, respectively, but none was found for CB-47. By comparing the change of dihedral angle of the aromatic rings and energy barrier, non-ortho-substituted PBDEs/PCBs have larger dihedral angle adjustment space and flexibility, which results in stronger interaction and binding capability with DOM than ortho-substituted isomers. This paper shed some lights on the effect of substituent position on the environmental behaviors of PBDEs and PCBs.

关 键 词：相互作用机制 多溴联苯醚 多氯联苯 取代位置 DOM 有机污染物 环境行为 溶解性有机物 

分 类 号：X13[环境科学与工程—环境科学]