Volatile components of Thymus vulgaris L. from wild-growing and cultivated plants in Jordan

The composition of the essential oil hydrodistilled from the aerial parts of Thymus vulgaris L. grown in Jordan has been determined by GC and GC-MS. Variations in oil composition and yield between cultivated and wild-growing plants collected from different localities, at different altitudes, have been also evaluated. Higher oil yields were observed in plants growing wild (3.7-5.6% of dried material) than in cultivated plants (1.1-2.0%), and those collected from the Mshaqar region, in the middle of Jordan and at the highest altitude, were the richest in oil (similar to 5.4%). Generally, the oil was characterized by marked levels of phenolic monoterpenoids (mainly thymol and carvacrol) in the range 70.8-89.0%. High levels of the monoterpenoid hydrocarbons p-cymene (3.4-8.2%) and gamma-terpinene (1.6-7.7%) were also observed. Other major components were 1,8-cineole (up to 2.1%), alpha-thujone (up to 1.2%), camphor (up to 1.1%) and fl-caryophyllene (0.2-2.8%). With the exception of plants growing wild in the Ramtha region, in the far north of Jordan, carvacrol was found as the principal phenol of all other oils (50.6-86.1%) and was dominant (>85%) in wild plant oils. The oil from Ramtha was characterized by the highest level of thymol (similar to 63.8%) as the dominant phenol and was most abundant in p-eymene (8.2%), 1,8-cineole (2.1%) and gamma-terpinene (7.7%). In addition to assigning carvacrol or thymol chemotypes to the plant, the high content of active monoterpenoid phenols strongly suggests a potential use of Jordanian thyme oil in cough products and antimicrobial-herbal drug combinations. Copyright (C) 2007 John Wiley & Sons, Ltd.