基于DFT的二噁英脂-水分配系数QSPR研究  

QSPR Study on the Lipid-Water Partition Coefficients of Dioxins Based on DFT

作　　者：谷成刚[1] 蒋新[1] 卞永荣[1] 余贵芬[1] 

机构地区：[1]中国科学院南京土壤研究所土壤与农业可持续发展国家重点实验室,南京210008

出　　处：《环境科学》2008年第5期1330-1335,共6页Environmental Science

基　　金：国家重点基础研究发展规划(973)项目(2002CB410805);国家杰出青年科学基金项目(40325001)

摘　　要：基于密度泛函理论,利用多氯二苯并对二噁英(PCDDs)和多氯二苯并呋喃(PCDFs)几何构型全优化而得的量子化学和延伸计算参数:前线轨道能、熵、无迹四极矩、分子绝对硬度、电负性和亲电指数等,对两类化合物在(虹鳉)脂-水间的平衡分配性质进行了定量化模型研究,并由多元线性回归分析(MLR)建立了二次函数型的定量结构-性质相关关系(QSPR):lgKbw=5.343-0.001(S-125.480)2-0.355(ω-3.239)2+0.006(Qzz-2.950)2-22.728(η-2.365)2.结果表明,模型具有较高的拟合优度与稳健性,其决定系数和交叉验证相关系数分别为0.943和0.908,且模型的内外部预测性能理想,总体质量明显优于SOFA(solubility parameter for fate analysis)计算结果,可用于未知脂-水分配性质的预测;PCDD/Fs脂-水平衡分配(系数)主要与分子体积以及由电荷分布决定的芳烃分子间相互作用有关,也受潜在的生物转化和分子反应性的影响.With computational method of density functional theory （DFT）, quantified model study of equilibrium partitioning properties of polychlorinated dibenzo-p-dioxins （PCDDs） and dibenzofurans （PCDFs） between lipid phase of organism （ Poecilia reticulata ） and water phase was carried out based on quantum chemical and further calculated parameters, namely frontier orbital energies, entropies, traeeless quadrupole moments as well as molecular absolute hardness, eleetronegativities and eleetrophilieity indices, which all were derived from full geometry optimization of PCDD/Fs. Through multiple linear regression （MLR） analyses, quantitative structure-property relationship （QSPR） was successfully proposed in the form of multi-parameter quadratic function： lgKbw = 5.343 - 0.001 （ S - 125.480）^2 - 0.355 （ω - 3.239）^2 ＋ 0.006（ Qzz -2.950）^2 -22.728（η- 2.365）^2. It was shown that the obtained QSPR had higher goodness of fitting and robustness, determination coefficient and cross-validated correlation coefficient being 0.943 and 0.908 respectively, and it was also provided with ideal interior and exterior predictive abilities so that it could be used for prediction of unknown lipid-water partitioning properties. By comparison, QSPR in this research was superior to that from previous SOFA （solubility parameter for fate analysis ） method on the whole. Lipid-water partitioning properties （coefficients） of PCDD/Fs should be mainly related to molecular volume and aryl hydrocarbon molecular interactions determined by charge distribution. To a certain degree, they also might be influenced by potential biotransformation and molecular reactivity.

关 键 词：二噁英 虹鳉 脂-水分配系数 密度泛函理论(DFT) 定量结构-性质相关关系(QSPR) 

分 类 号：X131[环境科学与工程—环境科学]