116 Insectary Building, Department of Entomology, Iowa State University, Ames, Iowa, 50011, USA.
J Agric Food Chem. 2009 Aug 26;57(16):7618-25. doi: 10.1021/jf900964e.
The plant terpenoids encompass a diversity of structures and have many functional roles in nature, including protection against pest arthropods. Previous studies in this laboratory have identified naturally occurring sesquiterpenes contained in essential oils from two plants, amyris (Amyris balsamifera) and Siam-wood (Fokienia hodginsii), that are significantly repellent to a spectrum of arthropod pests. In efforts to further examine the biological activity of this class of compounds 12 of these plant-derived sesquiterpenes have been isolated, purified, and assayed for spatial and contact repellency against the yellow fever mosquito, Aedes aegypti . These data were used to develop quantitative structure-activity relationships that identified key properties of the sesquiterpene molecule, including electronic and structural parameters that were used to predict optimal repellent activity. There were notable similarities in the models developed for spatial repellency over five time points and for contact repellency. Vapor pressure was an important component of all repellency models. Initial levels of spatial repellency were also related to polarizability of the molecule and lowest unoccupied molecular orbital (LUMO) energy, whereas the equation for late spatial repellency was dependent on other electronic features, including Mulliken population and electrotopological state descriptors. The model identified for contact repellency was the best fit and most significant model in this analysis and showed a relationship with vapor pressure, Mulliken population, and total energy.
植物萜类化合物具有多种结构，在自然界中具有许多功能作用，包括抵御害虫的侵害。本实验室的先前研究已经鉴定出两种植物精油中所含的天然倍半萜类化合物，Amyris（Amyris balsamifera）和Siam-wood（Fokienia hodginsii），对多种节肢动物害虫具有显著的驱避作用。为了进一步研究这类化合物的生物活性，从这两种植物中分离、纯化了 12 种植物衍生的倍半萜类化合物，并对其空间和接触驱避性进行了测定，以对抗黄热病蚊子 Aedes aegypti。这些数据用于开发定量构效关系，确定倍半萜分子的关键性质，包括电子和结构参数，用于预测最佳驱避活性。在五个时间点的空间驱避和接触驱避方面，所开发的模型具有显著的相似性。蒸气压是所有驱避模型的重要组成部分。初始空间驱避水平也与分子的极化率和最低未占据分子轨道（LUMO）能量有关，而晚期空间驱避方程则取决于其他电子特征，包括 Mulliken 布居和电拓扑状态描述符。接触驱避模型是该分析中最佳拟合和最显著的模型，与蒸气压、Mulliken 布居和总能量有关。
