Effect of separation method on chemical composition and insecticidal activity of Lamiaceae isolates

Abstract Supercritical fluid extraction was used to isolate volatile compounds from savory ( Satureja hortensis L.), thyme ( Thymus vulgaris L.), lavender ( Lavandula angustifolia L.) and peppermint ( Mentha piperita L.). Three types of extracts were prepared using the benefit of variable solvent power of supercritical carbon dioxide under different extraction conditions. The composition and toxicity of CO 2 extracts, products of Soxhlet extraction with hexane and ethanol, and essential oils obtained by hydrodistillation were compared. The composition of volatile compounds in the isolates was determined by gas chromatography. The acute toxicity of the isolates was evaluated in Spodoptera littoralis , Musca domestica , Culex quinquefasciatus , and Leptinotarsa decemlineata . The highest acute toxicity was exhibited by essentials oils, followed by CO 2 extracts. The lowest LD 50 value, 22 μg, was measured for savory essential oil against the larvae of L. decemlineata .