Advanced technology for purification of N-alkylamides from Acmella oleracea (L.) R.K. Jansen and development of innovative, safe and eco-friendly larvicidal extracts

The recent increase of insecticide resistance highlighted an urgent need for innovative products from natural sources. The aim is to reduce the excessive use of synthetic pesticides boosting resistance development in mosquitoes and causing serious threats to human health and environment [ 1 ]. A promising candidate is Acmella oleracea (L.) R.K. Jansen (Asteraceae). Its known insecticidal activity depends on the presence of N -alkylamides, mainly represented by spilanthol. The research on this compound evidenced the necessity for innovative and solvent-free extraction protocols that could substitute the traditional techniques. In this work, an eco-friendly N -alkylamides-enriched fraction (AEF) from A. oleracea was obtained by combining for the first time supercritical fluid extraction (SFE) and wiped-film short path molecular (WSM) distillation techniques. As outlined by the HPLC-DAD analysis, this fraction was characterized by a significantly higher content of spilanthol and N -alkylamides than the SFE. Then, larvicidal assays were performed against 3 rd instar larvae of Aedes albopictus Skuse, Anopheles stephensi Liston, and An. gambiae Giles to evaluate the activity of SFE, AEF, and pure spilanthol. They showed that the insecticidal activity of AEF is comparable to that of spilanthol and higher than that of SFE. Moreover, the dermal safety of these products was confirmed on human keratinocytes (HaCaT) [ 2 ]. Thanks to this study, new plant-derived pesticides could be manufactured through the utilization of WSM distillation to obtain a completely green product. In addition, it continues to pave the way for the development of effective, eco-friendly and safe botanical insecticides starting from active ingredients found in plant extracts. Publication History Article published online: 05 March 2026 © 2026. Thieme. All rights reserved. Georg Thieme Verlag KG Oswald-Hesse-Straße 50, 70469 Stuttgart, Germany