Cytotoxicity and 2D-QSAR study of some heterocyclic compounds

Herein we have studied the cytotoxicity and quantitative structure–activity relationship (QSAR) of heterocyclic compounds containing cyclic urea and thiourea nuclei. A set of 22 hydantoin and thiohydantoin related heterocyclic compounds were investigated with respect to their LC₅₀ values (Log of LC₅₀) against brine shrimp lethality bioassay in order to derive the 2D-QSAR models using MLR, PLS and ANN methods. The best predictive models by MLR, PLS and ANN methods gave highly significant square correlation coefficient (R²) values of 0.83, 0.81 and 0.91 respectively. The model also exhibited good predictive power confirmed by the high value of cross validated correlation coefficient Q² (0.74).     

基于迭代自组织数据分析算法与蚁群算法建立有机物黏度的QSPR模型

为了构建310个有机物分子结构与其黏度之间的定量结构-性质关系(QSPR)模型,探讨影响有机物液体黏度的结构因素,首先运用迭代自组织数据分析技术(ISODATA)将样本集初步分类,划分为训练集和测试集,进而应用DRAGON2.1软件计算310个有机物分子的分子结构描述符,以蚁群算法(ACO)筛选分子描述符,得到5个参数,随后分别采用多元线性回归法(MLR)和支持向量机法(SVM)建立ACO-MLR模型和ACOSVM模型.结果表明,非线性ACO-SVM模型(相关系数R2train=0.9013,R2test=0.9026)的性能优于线性ACOMLR模型(R2train=0.7680,R2test=0.8725).ACO-MLR模型和ACO-SVM模型对测试集所得预测值与实验值的相关系数分别为0.934和0.950,预测效果令人满意.本文应用Williams图对模型的应用域进行了一定的研究,所建立的模型为工程上提供了一种根据分子结构预测有机物黏度的有效方法.