苯醛和含氮芳香化合物毒性与电子结构关系的研究

Study on quantitative relationships between electronic structure and toxicities of phenyl-aldehydes andnitrogen-containing aromatic molecules

应用半经验的PM3量子化学方法计算了 13种苯醛类化合物和 18种含氮芳香化合物的电子结构 ,分别对两类化合物的毒性与电子结构的关系进行研究 ,结果得到 :(1)苯醛类化合物的LUMO轨道能ELUMO普遍较低 ,LUMO与HOMO的能级差DELH越小 ,化合物越容易接受电子其氧化性越强 ,化合物的毒性越大 ;(2 )含氮芳香化合物的疏水参数logP、分子体积V赵大 ,毒性越大 ;而总能量E、DELH越小 ,毒性越大。根据所得两类化合物的QSAR ,可分别预测苯醛类化合物和含氮芳香化合物的毒性。

The quantum chemical indexes of 13 phenyl-aldehydes and 18 nitrogen-containing aromatic molecules were calculated by PM3 method. Two quantitative structure-activity relationships of phenyl-aldehydes and nitrogen-containing aromatic molecules between quantum chemical indexes and toxicitives were obtained as follows: (1)for phenyl-aldehydes: pLD 50 =-3.473-0.447 E LUMO, which indicated that the toxicities (pLD 50) of phenyl-aldehydes would increase when energy of the lowest unoccupied molecular orbital (E LUMO) decrease, while the polarity of C=O group and dipolar moment increase; (2)for nitrogen-containing aromatic molecules: pIGC= 0.936-5.24×10 -5 E-0.300 DELH, which indicated that toxicities (pIGC) of nitrogen-containing aromatic molecules would increase when molecular energy E and the difference of HOMO and LUMO energy DELH decrease. The molecular energy E decreased mainly because of the enlargement of molecular volume which resulted in the enlargement of logP.