Vo_2025_Molecules_30_

The chemical composition of leaf essential oil of the harmful invasive species Chromolaena odorata collected in Vietnam was analyzed by GC/MS and chiral GC. All three essential oil samples (O1, O2 and O3) in this study fell into chemotype I characterized by alpha-pinene/geigerene/germacrene D/(E)-beta-caryophyllene from a total of six different chemotypes. Chemotype I demonstrated larvicidal effects against Aedes aegypti (Linnaeus, 1762), Aedes albopictus Aedes albopictus (Skuse, 1894), Culex fuscocephala (Theobald, 1907) and Culex quinquefasciatus (Say, 1823), with 24 h LC(50) values ranging from 11.73 to 69.87 microg/mL. In contrast, its microemulsion formulation exhibited enhanced toxicity, yielding 24 h LC(50) values between 11.16 and 32.43 microg/mL. This chemotype also showed repellent efficacy against Ae. aegypti, with protection times ranging from 70.75 to 122.7 min. Fumigant toxicity was observed against Aedes aegypti, with LC(50) values of 40.27% at 0.5 h and 0.34% at 24 h. Molluscicidal activity was recorded with 48 h LC(50) values between 3.82 and 54.38 microg/mL against Indoplanorbis exustus (Deshayes, 1833), Pomacea canaliculate (Lamarck, 1822), Physa acuta (Draparnaud, 1805). Additionally, the chemotype exhibited acetylcholinesterase inhibitory activity, with an IC(50) value of 70.85 microg/mL. Antimicrobial potential was also demonstrated, with MIC values ranging from 2.0 to 128.0 microg/mL against Enterococcus faecalis, Staphylococcus aureus, Bacillus cereus, Escherichia coli, Salmonella enterica, and Candida albicans. The C. odorata essential oil can be considered as a potential bioresource for human health protection strategies.