Analysis of the essential oil of Lippia graveolens HBK from El Salvador

Essential oils from two samples of Lippia graveolens HBK (South American or Mexican oregano, common in El Salvador), were obtained by hydrodistillation and studied by GC and GC–MS. Forty-five compounds, constituting 92–93% of the oil, were identified. The two major components in both samples were carvacrol (71% and 34.6%, respectively) and thymol (5–7%, respectively). In addition, two unusual isomers, 2-isopropyl-4-methylphenol and 4-isopropyl-2-methylphenol, were found and identified by comparison with mass spectral data and retention indices and tentatively synthesized. Copyright © 2001 John Wiley & Sons, Ltd.