中文摘要：

用密度泛函理论（DFT）和逐步回归分析方法对具有抗菌活性的18种新合成的取代异噻唑啉酮类化合物进行了定量构效关系（QSAR）研究。在B3LYP/6-31G（d,p）水平上,对异噻唑啉酮类化合物进行了构型全优化,并提取部分量子化学参数,通过逐步多元回归分析,筛选了影响抗菌活性的主要因素,建立了定量构效关系方程。结果表明,C（5）的亲核电子密度fCN（5）与S（1）-N（2）的键级BS（1）-N（2）,是影响异噻唑啉酮类化合物抗大肠杆菌活性的主要因素,所得QSAR模型对该类化合物抗菌活性有较好的预测效果。

英文摘要：

The relationship between structure and antibacterial activity of 18 isothiazolone derivatives was studied by density functional theory（DFT） at the B3LYP/6-31G（d,p） basis set and stepwise multiple linear regression analysis（SMLR） method.The main independent factors which affected the activity of the compounds were determined by stepwise regression analysis,then a QSAR model was established.The result suggested that the nucleophilic frontier electron density of C（5） atom（fNC（5））,the bond order of S（1）-N（2）（BS（1）-N（2）） were the predominant factors affecting antibacterial activity against E.coil.The obtained QSAR model could provide theory reference to design isothiazolones with stronger antibacterial activity.