No abstract

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.
Óleos essenciais obtidos por hidrodestilação das folhas de Mentha pulegium L. e Mentha rotundifolia (L.) Huds. do Uruguay foram analisados por GC-FID e GC-MS. O grupo de monoterpenes oxigenados foi o mais importante em ambos os óleos, sendo que a pulegona, isomenthona e menthona foram os constituintes maioritarios no óleo de Mentha pulegium, no entanto, o ôxido de piperitenona e (Z)-hidrato de sabineno foram os maioritarios na Mentha rotundifolia. (-)-mentone, (+)-isomentone, (+)-isomenthol, (-)-menthol e (+)-pulegone enantioméricamente puras foram detectadas por cromatografía gasosa multidimensional no caso do óleo de Mentha pulegium

Essential oils of Baccharis uncinella DC and B. dracunculifolia DC collected from different wild populations growing in Bolivia, southern Brazil and Uruguay were analysed using gas chromatography and gas chromatographymass spectrometry techniques, to check for chemical variability. Cluster analysis led to the identi¼cation of two chemotypes for B. dracunculifolia, related to aromadendrane-or cadinane-derived components. As the timing of sampling of the plant material may have an in½uence on the composition of the essential oil isolated, the seasonal in½uence at the moment of harvesting was studied for two populations of each species. The results suggested that the ½owering season was optimal both species and this supported the practice of harvesting at the full bloom stage.

No abstract

Essential oils obtained by hydrodistillation from aerial parts of Hedyosmum angustifolium (Ruiz & Pavón) Solms-Laubach and H. scabrum (Ruiz & Pavón) Solms-Laubach from Bolivia were analysed by GC-FID and GC-MS. Monoterpene hydrocarbons, especially˛-andˇ-pinene, and oxygen containing monoterpenes, mainly 1,8-cineole and linalool, were the major constituents found in the oils of H. angustifolium. The oil of H. scabrum was mainly made up of monoterpenes, in particular υ-3-carene, the sesquiterpene hydrocarbons˛-gurjunene and germacrene D, and 3 0 , 4 0 -dimethoxypropiophenone. For both oils, the enantiomeric distribution of -pinene, sabinene,ˇ-pinene, limonene, linalool, terpinen-4-ol and˛-terpineol was studied by multidimensional HRGC-HRGC. The main difference between the oils corresponded to the reverse enantiomeric distribution found for linalool, indicating a clear index of different metabolic response in each species.