Quantitative Structure Activity Relatinship for Toxicity of Alkylphenols Compounds to Tetrahymena Pyriformis
15 Quantum chemical parameters were calculated at B3LYP/6-311G level by density functional theory method of Gaussian 03.These structure parameters involved in parameters of alkyl group′s substitutive positions and their correlations(NPCS) are taken as descriptors.Using VSMP(variable selection and modeling based on prediction) to selecte the best subset,a two variables model was developed for toxicity of 41 alkylphenols to Tetrahymena pyriformis as follows: pIGC50=(-1.6069±0.2019)+(-0.3839±0.0798)μ+(0.0264±0.0015)α,n=41,m=2,r=0.9434,RMSE=0.2548,Q=0.9170,RMSV=0.3066,F=153.8747.In order to validate the stability and the power of the model,41 alkyphenols were divided into two parts as odd set and even set,and built model respectively.A method called y-randomization was used to validate the models of whole sample,odd set and even set,and the models of odd set and even set passed all the tests for the power of prediction of QSAR model according to Tropsha.