Spectroscopic investigation and insecticidal effects of two natural alkynes from Artemisia campestris, 2,4-pentadiynylbenzene and capillene, against Spodoptera littoralis larvae and non-target organisms

Abstract

Plants of the Artemisia L. genus are known for several biological effects. However, comprehensive studies on their insecticidal activities, particularly focusing on the activity of the main metabolites, are still limited. This study examines the properties of the essential oil (EO) extracted by Artemisia campestris L. subsp. campestris (ACC), collected in Pantelleria island, Italy. This study focused on the insecticidal activity of ACC, evaluating the phytosanitary potential of two isolated natural alkynes: capillene and 2,4-pentadiynylbenzene. The EO was studied by GC-MS and 2D-NMR tecniques revealing that it was rich in alkyne compounds (59.04%), with capillene being the predominant component (40.03%). The HSQC study not only highlighted the clear presence of alkyne derivatives and β-pinene, but confirmed the identification carried out by GC and GC-MS. At the same time, the promising insecticidal efficacy of ACC against Spodoptera littoralis (Boisd.) larvae was found. The study demonstrated that ACC is a promising candidate for botanical insecticide development due to its effectiveness against S. littoralis larvae and its relative safety for non-target organisms.