定量计算萜类驱避化合物与二氧化碳缔合对其蚊虫驱避活性的影响

Quantitative calculation of the influence of the molecular association between terpenoid repellents and CO2 on their repellency against mosquitoes

为验证萜类驱避化合物与嗅觉引诱物二氧化碳存在缔合作用,并研究缔合作用对蚊虫驱避活性的影响。本研究借助计算化学的方法获得缔合体和缔合能量,利用Gaussian View和Gaussian03W软件分别构建和优化二氧化碳、22个萜类蚊虫驱避化合物以及它们与二氧化碳缔合后的三维分子结构,经Ampac8.16转化后,获得它们的缔合能量。借助定量构效关系计算方法研究缔合作用对驱避活性的影响,利用Codessa2.7.10计算获得驱避剂和缔合体的各类结构描述符,从包括缔合体结构描述符及特征描述符在内的各类结构参数中筛选显著性参数,以萜类驱避化合物对白纹伊蚊Aedes albopictus的校正驱避率的对数值为活性数据,建立结构描述符与驱避活性的定量构效关系(quantitative structure-activity relationship,QSAR)模型。结果获得了22个萜类驱避化合物与二氧化碳缔合的缔合能量,计算显示它们之间存在缔合作用并且可以形成缔合体;获得1个R2为0.9643的4参数QSAR模型,这4个参数所对应的结构描述符分别是COM-WNSA-3 Weighted PNSA(PNSA3*TMSA/1000)[Zefirov’s PC],f-TerCO2-Min e-n attraction for a C-O bond,M-Max 1-electron reaction index for an Oatom,M-Min(>0.1)bond order of an H atom,前2个参数分别为缔合体的整体结构描述符和碎片特征描述符。计算化学结果表明,萜类驱避化合物与二氧化碳存在缔合作用,该缔合作用对驱避活性的影响显著。

This study attempted to demonstrate the molecular association between terpenoid repellents and C02, and investigated its influence on their repellency against mosquitoes. Association energy was calculated using computational chemistry software： three-dimensional structures of C02, 22 terpenoid repellents and their complexes that are associated with C02 were built and optimized using Gaussiau View and Gaussian 03W, respectively, and the association energy were obtained in Ampac 8.16. Dependence of repellency on the molecular association was studied by quantitative structure-activity relationship method. Significant activity-affecting parameters were screened from structural descriptors of 22 terpenoid repellents and their complexes, as well as descriptors of characteristic fragments of complexes, which were all calculated by Codessa 2.7.10. The quantitative structure-activity relationship （QSAR） model was obtained to analyze the relationship between the structural descriptors and the logarithm value of the corrected repelling time against Aedes albopictus. Association energies between terpenoid repellents and CO2 were thus calculated, and the results showed that the molecular association between them was strongenough to form the complexes. A statistical QSAR model with four parameters and with R2 of 0. 9643 was built, and the most significant activity-affecting parameters were COM-WNSA-3 Weighted PNSA （PNSA3 ＊ TMSA/1 000） [ Zefirov＇ s PC ], f-TerCOz-Min e-n attraction for a C-O bond, M-Max 1-electron reactivity index for an O atom, M-Min （ 〉 0.1 ） bond order of an H atom, respectively. The results of computational chemistry calculation show that the molecular association between terpenoid repellents and CO2 is present, and the association can affect the repellency greatly.