在B3LYP/6-31G*水平上采用高斯09全优化计算了50个P450 1A2抑制剂的量子化学参数,应用基于预测的模型变量选择方法(VSMP)选择描述子最佳子集,建立了最高轨道占有能(EHOMO)和分子体积(Vm)与萘、内酯衍生物及其他化合物对细胞色素氧化酶P450 1A2抑制剂的两变量线性QSAR模型,结果表明:所选的2个分子结构描述符与50个抑制剂的活性之间具有很强的线性关系(相关系数r2=0.907 0)和内部预测能力(留多法交叉验证相关系数q2=0.751 7)。同时,将50个化合物分成奇数集和偶数集各自进行筛选建模,并彼此进行外部预测,对全部样本集、奇数集和偶数集样本模型进行了y-Randomization检验,结果表明描述符EHOMO和Vm建立的模型均非常稳定并具有很高的预测能力。
In order to establish the QSAR model of inhibitors of cytochrome P450 1A2,19 quantum chemical and thermodynamics parameters of 50 compounds,which include naphthalene,lactone and quinoline derivatives,are calculated at B3LYP/6-31G* level by density funcional theory method with Gaussian 09 program.Using VSMP(variable selection and modeling based on prediction) technique to select the optimal subset,a two-descriptor QSAR model is constructed.The results of modeling show that there is a strong linear relationship between two descriptors(energies of the highest occupied molecular orbital,EHOMO and the molecular volume,Vm) and the inhibited activity of 50 compounds(correlation coefficient of model,r2=0.907 0),and high inner predicted ability(correlation coefficient leave-multiple-out cross validation,q2=0.751 7).Meanwhile,50 compounds are divided into odd set and even set,and two-descriptor QSAR model are constructed with external validated by each other.Then,the y-Randomization validation is performed within the models of all compounds set,odd set and even set.The models of three sets built by EHOMO and Vm have stability and high prediction.