部分取代苯定量结构-生物降解相关性(QSBR)研究

Quantiative relationships study for the structure and degradability of substituent benzenes

采用Chems 3D中量子化学MOPAC -AM1法计算了 7种间苯胺类和 8种对苯酚的分子最高占有轨道能EHOMO、分子最低空轨道能ELUMO.用QSAR程序软件包查得分子体积Vm.结合分子连接性指数 ( 3X ,3XV)对生物降解二级速率常数对数lgKb 进行了定量结构 -生物降解相关性 (QSBR)分析 .通过回归分析 ,得到如下两个回归方程 :lgKb=-0 .832 -0 .1 1 8Vm+1 .74 83XV,n =1 5,R2 =0 .832 ,SE =0 .577,F =2 9.7,p =0 .0 0 0 ( 1 )lgKb=0 .1 2 4Vm+1 .74 93XV,n =1 5,R2 =0 .998,SE =0 .5591 ,F =4 1 48.99,p =0 .0 0 0 . ( 2 )

Energy of the highest occupied molecular orbital ( E HOMO ) and energy of the lowest unoccupied molecular orbital ( E LUMO ) of 6 m-anilines and 7 p-phenols were calculated by quantum chemical method MOPAC 6.0-AM1 in Chems 3D software. Molecular volume ( V m) was calculated by QSAR software. Meanwhile 2 molecular connectivity indices ( 3X, 3X V) were calculated by definition. The quantitative structure-biodegradability relationship studies were performed with logarithm of biotransformation second-order rate constant lg K b. Through multiple regression, 2 equations were obtained as follows: lg K b=-0.832-0.118 V m+1.748 3 X V, n=15,R 2=0.832,SE=0.577,F=29.7,p=0.000 (1) lg K b=0.124 V m+1.749 3X V, n=15,R 2=0.998,SE=0.559 1,F=4 148.99,p=0.000 (2) The QSBR equations were used to calculate biodegradability and residuals, and biodegradation mechanism was discussed.