Essential oils of Mentha pulegium and Mentha rotundifolia from Uruguay

Essential oils obtained by hydrodistillation from leaves of Mentha pulegium L. and Mentha rotundifolia (L.) Huds. from Uruguay were analysed by GC-FID and GC-MS. Oxygen-containing monoterpenes were the main group of constituents in both oils. Pulegone, isomenthone and menthone were the major components in the oil of M. pulegium, whereas piperitenone oxide and (Z)-sabinene hydrate were the major ones in M. rotundifolia. Enantiomerically pure (-)-menthone, (+)-isomenthone, (+)-isomenthol, (-)-menthol and (+)-pulegone were detected by multidimensional gas chromatography in the case of M. pulegium oil.