Universidad Nacional de Córdoba, Facultad de Ciencias Exactas, Físicas y Naturales, Departamento de Química, Cátedra de Química Biológica, Córdoba, Argentina; Instituto de Investigaciones Biológicas y Tecnológicas (IIBYT), CONICET, Córdoba, Argentina.
Universidad Nacional de Córdoba, Facultad de Ciencias Exactas, Físicas y Naturales, Departamento de Química, Cátedra de Química Biológica, Córdoba, Argentina; Instituto de Investigaciones Biológicas y Tecnológicas (IIBYT), CONICET, Córdoba, Argentina.
Biophys Chem. 2021 Feb;269:106526. doi: 10.1016/j.bpc.2020.106526. Epub 2020 Dec 14.
The insecticidal activity of Mentha oil and its main components has been tested and established for various insects/pests. Several mint ketones have demonstrated to act on GABA receptors (GABA-R), a transmembrane channel target of several important insecticides whose activity can be modulated by surface-active compounds and by changes in the physical properties of the lipid membrane. In the present work, we analyze the capacity of monoterpenic ketones most commonly found in Mentha species, pulegone and menthone, to interact with DPPC membranes by molecular dynamics (MD) simulations and Langmuir monolayers. The experimental results indicate that the presence of menthone and pulegone in the subphase modify the interfacial characteristics of DPPC isotherms. The changes were reflected as expansion of the isotherms and disappearance or bringing forward of DPPC phase transition. MD simulation corroborate these results and indicate that both ketones are located at the region of the carbonyl group, at the interface with the acyl chains. Ketone intercalation between lipid molecules would induce an increasing intermolecular interaction, diminishing the film elasticity and causing an ordering effect. Our results suggest that the insecticidal activity of both ketones could involve their interaction with lipid molecules causing disturbance of the cell membrane as postulated for several larvicide compounds, or at least modulating the receptor surrounding.
薄荷油及其主要成分的杀虫活性已针对各种昆虫/害虫进行了测试和证实。几种薄荷酮已被证明作用于 GABA 受体（GABA-R），GABA-R 是几个重要杀虫剂的跨膜通道靶标，其活性可被表面活性剂和脂质膜物理性质的变化调节。在本工作中，我们通过分子动力学（MD）模拟和 Langmuir 单层分析了薄荷属植物中常见的单萜酮——薄荷酮和薄荷脑与 DPPC 膜的相互作用。实验结果表明，亚相中存在薄荷酮和薄荷脑会改变 DPPC 等温线的界面特性。这种变化表现为等温线的膨胀以及 DPPC 相变的消失或提前。MD 模拟证实了这些结果，并表明这两种酮都位于羰基区域，与酰基链的界面处。酮在脂质分子之间的插入会诱导分子间相互作用的增加，降低膜的弹性并产生有序化效应。我们的结果表明，这两种酮的杀虫活性可能涉及它们与脂质分子的相互作用，从而导致细胞膜紊乱，就像几种杀虫剂化合物所假设的那样，或者至少调节受体周围的环境。
