Essential oil variability of Thymus baeticus growing wild in southeastern Spain

Essential oils of Thymus baeticus collected from southeastern Spain were analysed using gas chromatography and gas chromatography-mass spectrometry techniques, to check for chemical variability The sampled individuals showed important differences in their content of 1,8-cineole, borneol, linalool, geranial, tr-sabinene hydrate and terpinen-4-ol with some strong inter-relationships between these compounds. Thymol and carvacrol were recorded only in small quantities. Principal component analysis and cluster analysis revealed great variability, with the samples being quite isolated and distancing from each other, although a major group of individuals characterized by terpinen-4-ol was detected. Multidimensional scaling analysis of the percentage concentration for each identified component of the essential oil showed terpinen-4-ol, 1,8-cineole and borneol to be the most divergent components. (C) 1999 Elsevier Science Ltd. All rights reserved.