Essential Oil Characterization of Thymus vulgaris from Various Geographical Locations

Abstract

Thyme (<i>Thymus vulgaris</i> L.) is a commonly used flavoring agent and medicinal herb. Several chemotypes of thyme, based on essential oil compositions, have been established, including (1) linalool; (2) borneol; (3) geraniol; (4) sabinene hydrate; (5) thymol; (6) carvacrol, as well as a number of multiple-component chemotypes. In this work, two different <i>T. vulgaris</i> essential oils were obtained from France and two were obtained from Serbia. The chemical compositions were determined using gas chromatography-mass spectrometry. In addition, chiral gas chromatography was used to determine the enantiomeric compositions of several monoterpenoid components. The <i>T. vulgaris</i> oil from Nyons, France was of the linalool chemotype (linalool, 76.2%; linalyl acetate, 14.3%); the oil sample from Jablanicki, Serbia was of the geraniol chemotype (geraniol, 59.8%; geranyl acetate, 16.7%); the sample from Pomoravje District, Serbia was of the sabinene hydrate chemotype (<i>cis</i>-sabinene hydrate, 30.8%; <i>trans</i>-sabinene hydrate, 5.0%); and the essential oil from Richerenches, France was of the thymol chemotype (thymol, 47.1%; <i>p</i>-cymene, 20.1%). A cluster analysis based on the compositions of these essential oils as well as 81 additional <i>T. vulgaris</i> essential oils reported in the literature revealed 20 different chemotypes. This work represents the first chiral analysis of <i>T. vulgaris</i> monoterpenoids and a comprehensive description of the different chemotypes of <i>T. vulgaris</i>.