Department of Botany and Ecology, University of Zielona Góra, Szafrana 1, 65-516 Zielona Góra, Poland.
Department of Chemistry, Wrocław University of Environmental and Life Sciences, Norwida 25, 50-375 Wrocław, Poland.
Int J Mol Sci. 2020 Oct 28;21(21):8029. doi: 10.3390/ijms21218029.
Citral is well known for its antimicrobial, antifungal, and insecticidal activities. Natural sesquiterpene α-methylenelactones also exhibit a broad spectrum of biological activities. The aim of the study was to explore the effect of structural changes to citral molecules on citral behavior-modifying activity towards . Specifically, the effects of the introduction of a γ-lactone moiety and methylene groups in α and γ positions of the lactone ring were investigated. The lactones were obtained in five-step (saturated lactone and γ-methylenelactone) or six-step (α-methylenelactone and α,γ-dimethylenelactone) syntheses from citral. The synthetic procedures and physical and spectral data of the lactones are presented. The settling behavior of freely moving aphids in choice and no-choice situations was monitored. The probing behavior of tethered using the Electrical Penetration Graph (EPG) technique was also analyzed. Citral appeared a strong repellent and pre-ingestive and ingestive probing deterrent to . The incorporation of a lactone moiety caused the loss of the repellent activity. α-Methylenelactone inhibited aphid settling and probing activities at pre-ingestive and ingestive phases. The saturated γ-lactone and α,γ-dimethylenelactone were the settling post-ingestive deterrents to , which did not affect aphid probing activity. γ-Methylenelactone did not affect aphid behavior.
柠檬醛具有良好的抗菌、抗真菌和杀虫活性。天然倍半萜α-亚甲基-γ-内酯也表现出广泛的生物活性。本研究旨在探索柠檬醛分子结构变化对其行为修饰活性的影响。具体而言，研究了内酯环α和γ位引入亚甲基和γ-内酯部分对柠檬醛行为修饰活性的影响。这些内酯是通过五步（饱和内酯和γ-亚甲基内酯）或六步（α-亚甲基内酯和α，γ-二亚甲基内酯）合成从柠檬醛得到的。介绍了合成步骤以及内酯的物理和光谱数据。监测了自由移动蚜虫在选择和非选择情况下的沉降行为，并使用电穿透图（EPG）技术分析了束缚蚜虫的探测行为。柠檬醛对蚜虫表现出强烈的驱避和预取食及取食探测抑制作用。内酯部分的引入导致驱避活性丧失。α-亚甲基内酯抑制蚜虫在预取食和取食阶段的沉降和探测活动。饱和γ-内酯和α，γ-二亚甲基内酯是蚜虫取食后的沉降抑制剂，不影响蚜虫的探测活动。γ-亚甲基内酯不影响蚜虫的行为。
