Structural Characterization and Toxicity Prediction of Some Organic Compounds

A new molecular structural characterization(MSC)method called molecular vertexes correlative index(MVCI)was constructed in this paper.The index was used to describe the structures of 45 compounds and a quantitative structure-activity relationship(QSAR)model of toxicity(–lgEC50)was obtained through multiple linear regression(MLR)and stepwise multiple regression(SMR).The correlation coefficient(R)of the model was 0.912,and the standard deviation(SD)of the model was 0.525.The estimation stability and prediction ability of the model were strictly analyzed by both internal and external validations.The Leave-One-Out(LOO)Cross-Validation(CV)correlation coefficient(RCV)was 0.816 and the standard deviation(SDCV)was 0.739,respectively.For the external validation,the correlation coefficient(Rtest)was 0.905 and the standard deviation(SDtest)was 0.520,respectively.The results showed that the index was superior in molecular structural representation.The stability and predictability of the model were good.     

酚类污染物土壤吸收系数定量预测

本文将分子结构表征方法(MEDV)进行改进,得到按非氢原子间距离分类的分子电性距离矢量,将该矢量用于酚类化合物结构表征,并与其土壤吸收系数(lgKoc)建立定量结构与性质关系(QSPR)模型。利用逐步回归(SMR)得到的4变量模型复相关系数(R2)为0.970、标准偏差(SD)为0.198,留一法(LOO)交互校验(CV)预测值的复相关系数(R2cv)为0.916、标准偏差(SDcv)为0.337。结果表明该矢量具有较强的分子结构表达能力,模型具有良好的预测能力与稳定性。     

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.     

脂肪酸多聚甘油酯分子结构与性能相关性研究

采用量子化学MM+和AM1方法计算聚甘油和脂肪酸多聚甘油酯的分子结构参数,然后用逐步线性回归方法建立脂肪酸多聚甘油酯HLB值的定量结构性质(QSPR)模型,所得的预测模型中包含四个参数(单位质量分子所含氧原子数Xo、生成热ΔfHm、电子能Ee和水合能Eh),预测值及外部检验的复相关系数(R2)和标准偏差(SD)分别为0.9553、0.73722和0.9678、6.34426。结果表明,量子化学方法计算简单,对脂肪酸多聚甘油酯结构的表征能力较强,所建QSPR模型具有能较好的预测能力和较强的稳健性,并在一定程度上阐明了脂肪酸多聚甘油酯分子结构与性能之间的关系。     

三维全息原子场作用矢量用于HEPT类抗艾滋病药物的QSAR研究

采用本实验室新近提出的三维全息原子场作用矢量表征34个1-[(2-羟乙氧)甲基]-6-苯硫基胸腺嘧啶(HEPT)类抗艾滋病药物结构并与其活性建立定量构效关系模型. 采用逐步回归对变量进行筛选后, 运用多元线性回归(multiple linear regression, MLR)建模的复相关系数(R2cum)、交互校验的复相关系数(Q2cum)和模型的标准偏差(SD)分别为R2cum=0.928、Q2cum=0.883与SD=0.43, 均优于Hancsh报道的值(R2cum=0.911、Q2cum=0.863与SD=0.45). 模型具有良好的稳定性和预测能力, 表明三维全息原子场作用矢量能较好表征该类分子结构信息, 值得进一步推广应用.     

三维全息原子场作用矢量用于吡咯类抗艾滋病药物QSAR研究

采用三维全息原子场作用矢量(3D-HoVAIF)对32个吡咯类抗艾滋病药物进行结构参数化表征,并与其活性建立定量构效关系。分别采用多元线性回归(MLR)和偏最小二乘(PLS)进行建模,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=0.914、Q2cum=0.812、SD=0.236(MLR);R2cum=0.836、Q2cum=0.719、SD=0.314(PLS),结果均优于文献值(R2cum=0.667,Q2cum=0.581,SD=0.420)。所建模型具有良好的稳定性和预测能力,表明3D-HoVAIF能够较好地表征该类分子的结构,值得进一步推广应用。     

抗艾滋病药物环尿素类化合物的结构表征及其生物活性的定量预测

提出一种新的结构描述子-按氢分类的电距矢量（H-MEDV），并用于环尿素类 化合物抗人类免疫缺陷病毒（human immuno-deficiency virus，简称HIV）活性预 测，籍以多元线性回归（MLR）建立了H-MEDV与活性之间的相关模型，取得了良好 的结果，相关系数达R = 0.971。另外采用逐步回归（SMR）从原模型参数中选取了 5个参数建立一新模型，其模型相关系数为R = 0.938；继以留一法（Leave-one- out，LOO）进行交互检验，相关系数与之接近，R = 0.908；说明了定量结构活性 相关模型具有很好的稳定性和预测能力。     

Structural characterization and prediction of Kovats retention indices (RI) for alkylbenzene compounds

A new molecular structural characterization (MSC) method called the molecular vertex eigenvalue correlative index (MVECI) is constructed and used to describe the structures of 122 alkylbenzene compounds. Through multiple linear regression (MLR) and stepwise multiple regression (SMR), a quantitative structure-retention relationship (QSRR) model with correlation coefficient (R) of 0.995 is obtained. Through partial least-square regression (PLS), another QSRR model with correlation coefficient (R) of 0.991 is obtained. The estimation stability and prediction ability of the two models are strictly analyzed by both internal and external validations. For the internal validation, the cross-validation (CV) correlation coefficients (R _CV) of the two models are 0.993 and 0.988. For the external validation, the correlation coefficients (R _test) of the two models are 0.996 and 0.995, respectively. The results show that the stability and predictability of the models are good, and the molecular vertex eigenvalue correlative index can successfully describe the structures of alkylbenzene compounds.     

三维全息原子场作用矢量用于猫爪草脂肪酸的构效关系研究

运用三维全息原子场作用矢量(3D-HoVAIF)对猫爪草中18种脂肪酸进行定量构效关系(QSAR)研究。采用逐步回归(stepwise multiple regression,SMR)进行变量筛选,偏最小二乘回归(partial least square regression,PLS)建立定量构效关系模型。所建模型复相关系数(R2cum)、留一法交互校验(CV)复相关系数(Qc2um)分别为0.977和0.946。结果表明,3D-HoVAIF能较好表征猫爪草中脂肪酸的结构信息,且所建模型具有较好稳定性和预测能力。     

分子电性距离矢量用于多溴联苯醚分子结构表达及色谱保留时间预测

应用分子电性距离矢量(MEDV)对多溴联苯醚(PBDEs)的209种同系物进行结构表征.通过多元线性回归的方法,建立了PBDEs定量结构-色谱保留(QSRR)关系的6个变量和5个变量的两种模型.两种模型的建模计算值复相关系数R均为0.995;用留一法(LOO)进行了交互检验,其复相关系数(R2cv)分别为0.987和0...     

多环芳香硫化合物的定量结构-气相色谱保留指数关系

应用分子电性距离矢量(MEDV)对114个多环芳香硫化合物(PASHs)进行结构表征,通过多元线性回归建立了PASHs的气相色谱保留指数与MEDV参数之间的定量结构-保留值关系模型;同时采用逐步回归分析进行变量筛选,继而以留一法交互检验对所得优化模型进行预测能力评价,所建立的模型的相关系数为0.9947,交互检验相关系数为0.9940,表明该优化模型具有良好的稳定性和预测能力。此外,通过将样本集按2:1分成校准集和测试集预测,统计分析结果显示所建的模型具有良好的相关性和稳定性。本文所建的定量结构-保留值关系(QSRR)模型为预测PASHs的气相色谱保留指数提供了一个便捷有效的新方法。     

抗艾滋病新药吡喃酮类化合物的结构表征及其生物活性的定量预测

应用分子电性距离矢量(MEDV)对吡喃酮类化合物进行结构表征和抗人类免疫缺 陷病毒(human immuno-deficiencyvirus，简称HIV)的活性预测，通过逐步回归 (SMR)方法建立了MEDV与活性之间的定量模型，取得了良好的结果，其模型相关系 数R=0．958；继以留一法(Leave-one-out，LOO)进行交互检验，相关系数R=0． 835，说明定量相关模型具有良好的稳定性和预测能力．     

含氟取代苯类化合物定量结构与毒性关系研究

本文采用了按氢分类的分子电距矢量(H-MEDV)对19个含氟取代苯类化合物进行了结构表征。采用多元线性回归(MLR)方法建立了含氟取代苯类化合物的定量结构-毒性关系(QSAR)的5变量模型;上述模型对19个含氟取代苯类化合物毒性预测与实验值较好的吻合,其复相关系数(R)为0.918,标准偏差(SD)为0.382,结果表明所建模型具有较好的稳定性和预测能力。     

On QSAR Study of Stereoselectivity for Wittig Reaction

1INTRODUCTION Witting reaction is an important and well-known organic reaction.In this reaction system,phospho-nium ylides react with aldehydes or ketones to gene-rate olefins and phosphonium oxides.Obviously,the position of double bond in olefins is exactly the po-sition of carbonyl group in the reactants,so there are no other position isomers in products.Due to this advantage,Witting reaction has been widely used in organic synthesis[1].Witting reaction could introduce double bond to c…     

有机磷酸酯类化合物气相色谱定量结构保留关系研究

采用分子电性距离矢量(MEDV)表征有机磷酸酯类化合物的分子结构,运用多元线性回归建立定量结构-色谱保留关系(QSRR)模型,同时采用逐步回归结合统计检测对模型进行变量筛选,建立了35个有机磷酸酯类化合物在3种不同固定相(OV-101,DB-1701和DB-WX)上气相色谱保留指数(RI)与MEDV的定量相关模型.在3种固定相上的QSRR模型的建模计算值复相关系数(R)、留一法(leave-one-out)交互校验复相关系数(QCV)分别为0.998 0和0.995 1(OV-101);0.996 3和0.989 6(DB-1701);0.993 7和0.984 1(DB-WX),表明模型具有良好估计能力与稳定性.     

Structural Characterization of Volatile Components of Rosa Banksiae Ait for Estimation and Prediction of Their Linear Retention Indices and Retention Times

The molecular electronegativity-distance vector （MEDV） was used to describe the molecular structure of volatile components of Rosa banksiae Ait, and QSRR model was built up by use of multiple linear regression （MLR）. Furthermore, in virtue of variable screening by the stepwise multiple regression technique, the QSRR models of 10 and 6 variables and linear retention index （LRI） 10, 7 and 6 varieables were built up by combinating MEDV with the Ultra2 column GC retention time （tR） of 53 volatile components of Rosa Banksiae Air. The multiple correlation coefficients （R） of modeling calculation values of QSRR model were 0.906, 0.906, 0.949, 0.943 and 0.949, respectively. The cross-verification multiple correlation coefficients （RCV） were 0.903, 0.904, 0.867, 0.901 and 0.904, respectively. The results show that the models constructed could provide estimation stability and favorable predictive ability.     

地下水中挥发性有机物结构与色谱保留关系研究

本文采用分子电性距离矢量( Molecular Electronegativity-distancevector,MEDV)对地下水中26个挥发性化合物进行了结构表征,并与其色谱保留时间建立定量结构-保留关系(QSRR)模型.得到的MLR模型复相关系数(R2)为0.901,留一法(LOO)交互校验(CV)预测值的复相关系数(R2cv)为0.806;PLSR模型复相关系数(R2)为0.882,留一法(LOO)交互校验(CV)预测值的复相关系数(R2cv)为0.750.结果表明分子电性距离矢量(MEDV)能较好地表征该体系化合物结构,所建模型具有良好的稳定性与预测能力.