Computer simulation of properties of pheromon molecules of Siberian silk moth

• Published in: Сибирский лесной журнал
• Main Authors: P. V. Artyushenko, P. E. Tsikalova, F. N. Tomilin
• Format: Article in Journal/Newspaper
• Language: English; Russian
• Published: Russian Academy of Sciences, Siberian Branch Publishing House 2021
• Subjects: pheromones; chemical communication; density functional theory; atomic and electronic structure; absorption spectra; Forestry; SD1-669.5; taiga
• Online Access: https://doi.org/10.15372/SJFS20210507; https://doaj.org/article/1df1f9a8ae724b7eb500ec4e065426b8

The Siberian silk moth Dendrolimus sibiricus Tschetv. is one of the most dangerous pests of taiga forests. Large-scale outbreaks of the population and the expansion of the pest’s habitat attract scientists to the study of insect sex pheromones. The Siberian silk moths use pheromones to attract mating partners. Pheromone communication is a complex multistage process, including the synthesis of pheromone, the spread of odorous substances in the environment, the perception of the pheromone signal by other individuals, and the behavioral response of individuals receiving the signal. Effective transmission of the pheromone signal is ensured due to the preservation of the chemical composition and conformation of molecules during propagation in the air, as well as their ability to decompose at a certain time under the influence of external factors. The stability and reactivity of molecules is determined by their physicochemical characteristics. Structural and spectral properties of molecules were investigated using methods of computer molecular modeling. Quantum chemical calculations were performed using the density functional theory B3LYP/DFT, which is widely used to study small organic molecules. A detailed analysis of the atomic and electronic structure of molecules in the ground and excited states was carried out, and the absorption spectra of molecules were calculated. The wavelengths and absorption intensity were determined. Based on the data obtained, a conclusion was made about the stability of pheromone molecules to the effects of sunlight, an assessment was made of the possibility of changing the chemical composition and structure of molecules as a result of absorption of ultraviolet radiation. The calculated data obtained were compared with the data on the daily patterns of insects.