Polybrominated diphenyl ether congeners (PBDEs) might activate the AhR (aromatic hydrocarbon receptor) signal transduction, and thus might have an adverse effect on the health of humans and wildlife. Because of the li...Polybrominated diphenyl ether congeners (PBDEs) might activate the AhR (aromatic hydrocarbon receptor) signal transduction, and thus might have an adverse effect on the health of humans and wildlife. Because of the limited experimental data, it is important and necessary to develop structure-based models for prediction of the toxicity of the compounds. In this study, a new molecular structure representation, molecular hologram, was employed to investigate the quantitative relationship between toxicity and molecular structures for 18 PBDEs. The model with the significant correlation and robustness (r <sup>2</sup> = 0.991, q <sup>2</sup> <sub>LOO</sub> = 0.917) was developed. To verify the robustness and prediction capacity of the derived model, 14 PBDEs were randomly selected from the database as the training set, while the rest were used as the test set. The results generated under the same modeling conditions as the optimal model are as follows: r <sup>2</sup> = 0.988, q <sup>2</sup> <sub>LOO</sub> = 0.598, r <sup>2</sup> <sub>pred</sub> = 0.955, and RMSE (root-mean-square of errors) = 0.155, suggesting the excellent ability of the derived model to predict the toxicity of PBDEs. Furthermore, the structural features and molecular mechanism related to the toxicity of PBDEs were explored using HQSAR color coding.展开更多
利用分子全息技术研究了129个5-羧基苯并咪唑类HCV NS5B聚合酶抑制剂的结构与活性之间的关系.讨论了分子碎片大小、碎片区分参数及全息长度对模型质量的影响.利用偏最小二乘法(partial least square,PLS)建立了一组以99个化合物为训练...利用分子全息技术研究了129个5-羧基苯并咪唑类HCV NS5B聚合酶抑制剂的结构与活性之间的关系.讨论了分子碎片大小、碎片区分参数及全息长度对模型质量的影响.利用偏最小二乘法(partial least square,PLS)建立了一组以99个化合物为训练集的最优模型,该模型的交叉验证相关系数q^2=0.820,非交叉验证相关系数r^2=0.963,标准偏差SEE=0.213;用最优模型对由30个化合物组成的测试集进行预测,得到其相关系数r_(pred)~2=0.98,表明了该模型具有良好的预测能力及拟合能力.利用色码图对模型中不同原子及不同结构的贡献进行了解释,在此基础上根据最优HQSAR模型设计了几种具有良好抗HCV活性的苯并咪唑类HCV NS5B聚合酶抑制剂分子,为新型HCV NS5B聚合酶抑制剂的设计和优化提供了参考.展开更多
Topomer comparative molecular field analysis(Topomer Co MFA)and holographic quantitative structure-activity relationship(HQSAR)for 1302,5-diketopiperazine derivatives were used to build a three-dimensional quantitativ...Topomer comparative molecular field analysis(Topomer Co MFA)and holographic quantitative structure-activity relationship(HQSAR)for 1302,5-diketopiperazine derivatives were used to build a three-dimensional quantitative structure-activity relationship(3D-QSAR)model.The results show that the models have high predictive ability.For Topomer CoMFA,the cross-validated q^2 value is 0.710 and the non-cross-validated r^2 value is 0.834.The most effective HQSAR model shows that the cross-validation q^2 value is 0.700,the non-cross-validated r^2 value is 0.815,and the best hologram length value is 353 using connections and bonds as fragment distinctions.50 highly active 2,5-diketopiperazine derivatives were designed based on the three-dimensional equipotential map and HQSAR color code map.Finally,the molecular docking method was also used to study the interactions of these new molecules by docking the ligands into the diketopiperazine active site,which revealed the likely bioactive conformations.This study showed that there are extensive interactions between the new molecule and Arg156,Arg122 residues in the active site of diketopiperazine.These results provide useful insights for the design of potent of the new 2,5-diketopiperazine derivatives.展开更多
基金Supported by the Key Project of the National Natural Science Foundation of China (Grant No. 20737001)the National Natural Science Foundation Key Project of China (Grant No. 20737001)the Science and Technology Development Founda-tion Project of Nanjing Medical University (Grant No. 06NMUM021)
文摘Polybrominated diphenyl ether congeners (PBDEs) might activate the AhR (aromatic hydrocarbon receptor) signal transduction, and thus might have an adverse effect on the health of humans and wildlife. Because of the limited experimental data, it is important and necessary to develop structure-based models for prediction of the toxicity of the compounds. In this study, a new molecular structure representation, molecular hologram, was employed to investigate the quantitative relationship between toxicity and molecular structures for 18 PBDEs. The model with the significant correlation and robustness (r <sup>2</sup> = 0.991, q <sup>2</sup> <sub>LOO</sub> = 0.917) was developed. To verify the robustness and prediction capacity of the derived model, 14 PBDEs were randomly selected from the database as the training set, while the rest were used as the test set. The results generated under the same modeling conditions as the optimal model are as follows: r <sup>2</sup> = 0.988, q <sup>2</sup> <sub>LOO</sub> = 0.598, r <sup>2</sup> <sub>pred</sub> = 0.955, and RMSE (root-mean-square of errors) = 0.155, suggesting the excellent ability of the derived model to predict the toxicity of PBDEs. Furthermore, the structural features and molecular mechanism related to the toxicity of PBDEs were explored using HQSAR color coding.
基金supported by the National Natural Science Funds of China(21475081)the Natural Science Foundation of Shaanxi Province(2019JM-237)the Graduate Innovation Fund of Shaanxi University of Science and Technology。
文摘Topomer comparative molecular field analysis(Topomer Co MFA)and holographic quantitative structure-activity relationship(HQSAR)for 1302,5-diketopiperazine derivatives were used to build a three-dimensional quantitative structure-activity relationship(3D-QSAR)model.The results show that the models have high predictive ability.For Topomer CoMFA,the cross-validated q^2 value is 0.710 and the non-cross-validated r^2 value is 0.834.The most effective HQSAR model shows that the cross-validation q^2 value is 0.700,the non-cross-validated r^2 value is 0.815,and the best hologram length value is 353 using connections and bonds as fragment distinctions.50 highly active 2,5-diketopiperazine derivatives were designed based on the three-dimensional equipotential map and HQSAR color code map.Finally,the molecular docking method was also used to study the interactions of these new molecules by docking the ligands into the diketopiperazine active site,which revealed the likely bioactive conformations.This study showed that there are extensive interactions between the new molecule and Arg156,Arg122 residues in the active site of diketopiperazine.These results provide useful insights for the design of potent of the new 2,5-diketopiperazine derivatives.
