Structural Characterization and Acute Toxicity Prediction of Substituted Aromatic Compounds by Using Molecular Vertexes Correlative Index

A molecular structural characterization (MSC) method called molecular vertexes correlative index (MVCI) was used to describe the structures of 30 substituted aromatic compounds. Through multiple linear regression (MLR) and stepwise multiple regression (SMR), a quantitative structure-toxicity relationship (QSTR) model with 4 variables was obtained. The correlation coefficient (R) of the model was 0.9467. Through partial least-squares regression (PLS), another QSTR model with 5 principal components was obtained. The correlation coefficient (R) of the model was 0.9518. Both models were evaluated by performing the cross-validation with the leave-one-out (LOO) procedure and the Cross-Validation (CV) correlation coefficients (RCV) were 0.9208 and 0.9214, respectively. The results suggested good stability and predictability of the models, and the molecular vertexes correlative index could successfully describe the structures of the substituted aromatic compounds.     

2D-QSAR Studies on Triazolone Compounds Containing Benzenesulfonic Amide

The geometry structures of 6 triazolone compounds containing benzenesulfonic amide were fully optimized with DFT (Density Functional Theory) method at the B3LYP/6-31G level, and the structural and electronic parameters of the compounds were calculated. The hydrophobic and topological parameters of the title compounds were calculated by HyperChem software. The mono-and bi-parametric models between the parameters and biological activity of the compounds were analyzed by Multiple Linear Regression method based on Hansch-Fujita model. The results show that the activities of the title compounds were increased with higher hydrophobic property logP and molecular volume V, lower molecular energy ETOTAL and elec-tronegative of benzene ring Qph.     

QSPR Study on Octanol/water Partition Coefficient （lgKow） of Substituted Naphthalin Compounds

Structural parameters of 24 substituted naphthalin compounds were computed at four levels using Hartree-Fock and DFT methods. Based on the experimental data of octanol/water partition coefficient (lgKow),three-parameter (energy of the highest occupied molecular orbital (EHOMO),the most positive atomic net charges of molecule (q+) and molecular average polari-zability (α)) dependent equations were developed using structural parameters as theoretical des-criptors. Especially,lgKow dependent equation calculated at the HF/6-311G** level is more advantageous than others in view of their correlation and predictive abilities. This dependent equation was validated by variance inflation factors (VIF) and t-test methods and used to predict lgKow of eight designed compounds. Upon comparison,the predictive abilities of our work are all more advantageous than those calculated from molecular property calculator program.     

Estimation of n-Octanol/water Partition Coefficients （lgKow） and the Aqueous Solubility （-lgSw） of all PCDF Congeners by Density Functional Theory

1 INTRODUCTION As is widely known, PCDFs together with poly- chlorinated dibenzo-p-dioxins (PCDDs) and poly- chlorinated biphenyls (PCBs) have been included in many blacklists, such as “persistent organic pol- lutants (POPs)” and suspected “environmental en- docrine disruptors (EEDs)”. This is because PC- DFs are chemically and thermally stable and com- plex PCDF mixtures are generally resistant to bio- degradation. Although the concentration of these chemicals is quite low o…     

用从头算量化参数预测多氯代二苯并呋喃的1gKow

采用G98W程序包中的HF方法和6-31g(d)基组对135个多氯代二苯并呋喃(PCDFs)分子和二苯并呋喃进行了全几何优化计算．以计算所得的分子轨道能量、原子电荷作为PCDFs分子结构描述符，运用多元线性回归技术建立了PCDFs的lgKow与上述参数的四元线性方程，相关系数为0．9306，标准偏差为0．1849，用Jackknife法检验该模型的稳健性好，并对未有实验数据的85个PCDFs的lgKow进行了预测．