The Essential Oil Compositions of Three Teucrium Taxa Growing Wild in Sicily: HCA and PCA Analyses

Abstract

The chemical composition and the qualitative and quantitative variability of the essential oils of three taxa belonging to the <i>Teucrium</i> genus were studied. The investigated taxa, that grow wild in Sicily, were <i>Teucrium flavum</i> L. (section <i>Chamaedrys</i> (Mill.) Scheb.), <i>Teucrium montanum</i> and <i>Teucrium capitatum</i> L. of section <i>Polium</i> (Mill.) Scheb. Essential oils were extracted by hydrodistillation and analyzed by GC-MS. In total, 74 compounds were identified. Sesquiterpene hydrocarbons were found to be the main group for <i>T. flavum</i> (48.3%). <i>T. capitatum</i> consisted essentially of monoterpene hydrocarbons (72.7%), with <i>α</i>-pinene (19.9%), <i>β</i>-pinene (27.6%) and sylvestrene (16.6%) as the most abundant compounds whereas ledene oxide (12.1%), epiglobulol (13.5%) and longifolenaldehyde (14.5%) were identified as the main constituents among the oxygenated sesquiterpenes (63.5%) of <i>T. montanum</i>. Furthermore, a complete literature review on the composition of the essential oils of all the other accessions of these <i>Teucrium</i> taxa, studied so far, was performed. Hierarchical Cluster Analysis (HCA) and Principal Component Analyses (PCA) were used in order to demonstrate geographical variations in the composition of the essential oils.