Comparative chemistry and insect antifeedant effects of conventional (Clevenger and Soxhlet) and supercritical extracts (CO₂) of two Lavandula luisieri populations.

摘要

The objective of this study was the preparation of supercritical (SCE), conventional hydrodistilled (HDE) and organic solvent (OSE) extracts from two Iberian Lavandula luisieri populations (A and B) to study their chemical composition and their insect antifeedant properties against Spodoptera littoralis and Myzus persicae. HDE and SCE extracts had different chemical compositions and insect antifeedant effects, extracts from population A being more effective. Compounds 5-hydroxymethyl-2,3,4,4-tetramethylcyclopent-2-en-1-one (6) and (2,2,3,4-tetramethyl-5-oxocyclopent-3-en-1-yl)-methyl acetate (7) were the major components of the SCE fractions of both populations. The supercritical technique (SFE) improved the extraction of 6, 7, oxo-cadinol (8), hexadecanoic acid and several not identified compounds with respect to HDE. SCE extracts also exhibited increased antifeedant effects against S. littoralis and the aphid M. persicae (A-SCE). The biological effects of the active extracts cannot be accounted for those of their individual major components, suggesting additive or synergistic effects.