Essential oil and chemical compositions of wild and cultivated Thymus daenensis Celak and Thymus vulgaris L.

摘要

Thymus vulgaris L. and Thymus daenensis Celak from mint family (Lamiacae) traditionally being used as source of the essential oil and phenolic components derived from their different parts. Growth, oil yield and chemical components of T. vulgaris and T. daenensis grown in different regions in south-central of Iran were investigated. The hydro-distillated oils obtained from wild and cultivated thyme species were analyzed by GC-MS. Twenty four components in total were identified representing more than 85-98% of the oil composition, with thymol (33.9-70.3%), carvacrol (4.0-24.8%), gamma-terpinene (3.9-10.4%) and p-cymene (4.8-8.6%) in T. daenensis, and thymol (35.5-44.4%), carvacrol (4.4-16.1%), gamma-terpinene (10.5-11.9%) and p-cymene (8.5-16.1%) in T. vulgaris as major constitutes. Location had no significant effect on growth characteristics of the two thyme species, but the quantity and quality of their essential oils were different in different regions. T. daenensis cultivated in Saman region produced highest thymol (70.3%), whereas those cultivated in Shahrekord region produced highest oil yield (1.16%, v/w). T. daenensis wild growing produced highest carvacrol (24.8%). The results indicated that essential oils and their chemical compositions of Thymus species are strongly affected by environmental conditions and agronomic management practices. Cultivation of thyme, especially T. daenensis proved to be superior in both oil content and quality, in terms of substantial contents of phenolic monoterpenoids (thymol). Results of this study suggest that wild growing of T. daenensis in semiarid condition is not rich in essential oil and thymol, therefore farmers in semiarid regions should grow cultivated species for producing highest economic amount of extracted essential oil and thymol for pharmaceutical, therapeutic and food purposes