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 hydrodistillatio n and studied by GC and CC-MS. Forty-five compounds, constituting 92-93% of the oil, were identified. The two major components in both samples were ca rvacrol (71% and 34.6%, respectively) and thymol (5-7%, respectively). In a ddition, two unusual isomers, 2-isopropyl-4-methylphenol and 4-isopropyt-2- methylphenol, were found and identified by comparison with mass spectral da ta and retention indices and tentatively synthesized. Copyright (C) 2001 Jo hn Wiley & Sons, Ltd.