Semiempirical molecular orbital calculations on the unimolecular massspectrometric fragmentation of tetrahydroimidazole-substituted methylene β-diketones are carried outby Austin Model 1 method, and the calculated re...Semiempirical molecular orbital calculations on the unimolecular massspectrometric fragmentation of tetrahydroimidazole-substituted methylene β-diketones are carried outby Austin Model 1 method, and the calculated results give a strong support to ourexperimental results reported previously. The optimum of the investigated molecular configurationindicates that the two hydrogen atoms attached to nitrogen atom have different activities dueto their chemical environment; the relative energies of the ions in fragmentation pathway ofionized tetrahydroimidazole-substituted methylene β-diketones provide indirectly an evidencefor both the existence of ion/neutral complex and the stabilities of these ions.展开更多
目的对23个四氢-咪唑-苯二氮酮(TIBO)类抗艾滋病药物分子进行定量构效关系(QSAR)研究。方法采用本实验室新近提出的三维全息原子场作用矢量(3D-HoVAIF)表征TIBO类抗艾滋病药物分子结构。然后运用偏最小二乘回归(partial least square re...目的对23个四氢-咪唑-苯二氮酮(TIBO)类抗艾滋病药物分子进行定量构效关系(QSAR)研究。方法采用本实验室新近提出的三维全息原子场作用矢量(3D-HoVAIF)表征TIBO类抗艾滋病药物分子结构。然后运用偏最小二乘回归(partial least square regression,PLS)建立3D-HoVAIF描述符与TIBO类抗艾滋病药物活性之间的QSAR模型。结果用此方法建模的复相关系数(R2cum)、交互校验复相关系数(Q2cum)和模型的标准偏差(SD)分别为R2cum=0.824,Q2cum=0.778与SD=0.56,均优于文献值。结论3D-HoVAIF能较好表征TIBO类抗艾滋病药物分子结构信息,因而能建立具有良好稳定性和预测能力的QSAR模型。展开更多
文摘Semiempirical molecular orbital calculations on the unimolecular massspectrometric fragmentation of tetrahydroimidazole-substituted methylene β-diketones are carried outby Austin Model 1 method, and the calculated results give a strong support to ourexperimental results reported previously. The optimum of the investigated molecular configurationindicates that the two hydrogen atoms attached to nitrogen atom have different activities dueto their chemical environment; the relative energies of the ions in fragmentation pathway ofionized tetrahydroimidazole-substituted methylene β-diketones provide indirectly an evidencefor both the existence of ion/neutral complex and the stabilities of these ions.
文摘目的对23个四氢-咪唑-苯二氮酮(TIBO)类抗艾滋病药物分子进行定量构效关系(QSAR)研究。方法采用本实验室新近提出的三维全息原子场作用矢量(3D-HoVAIF)表征TIBO类抗艾滋病药物分子结构。然后运用偏最小二乘回归(partial least square regression,PLS)建立3D-HoVAIF描述符与TIBO类抗艾滋病药物活性之间的QSAR模型。结果用此方法建模的复相关系数(R2cum)、交互校验复相关系数(Q2cum)和模型的标准偏差(SD)分别为R2cum=0.824,Q2cum=0.778与SD=0.56,均优于文献值。结论3D-HoVAIF能较好表征TIBO类抗艾滋病药物分子结构信息,因而能建立具有良好稳定性和预测能力的QSAR模型。