Effect of Drought Stress on Essential Oil Composition of Thymus vulgaris L. (Chemotype 1, 8-cineole) from wild populations of Eastern Iberian Peninsula

[EN] 1,8-cineole defines a typical chemotype of Thymus vulgaris L. in Iberian Peninsula. This compound has a wide range of potentially useful bioactive properties. In order to study the influence of drought stress in the essential oil (EO) composition of this chemotype, sixty plants from six wild populations of Eastern Iberian Peninsula were distilled and analyzed by GC and GC/MS. The harvest dates (May and August) were selected in such a way that the typical summer drought in Mediterranean climates was the critical factor affecting EO composition. Despite the high intrapopulational variability, significant increases of 1,8-cineole were found after the drought period (21.8%-43.2%, in May, up to 42.6%-68.5% in August). On the other hand, individuals from one of the populations showed different profiles rich in linalool and camphor or sesquiterpenoid compounds, such as a-cadinol.Llorens Molina, JA.; Vacas González, S. (2016). Effect of Drought Stress on Essential Oil Composition of Thymus vulgaris L. (Chemotype 1, 8-cineole) from wild populations of Eastern Iberian Peninsula. Journal of Essential Oil Research. 29(2):145-155. doi:10.1080/10412905.2016.1211561S14515529

Composition of commercial Cape chamomile oil (Eriocephalus punctualus)

Cape chamomile oil obtained from the herb Eriocephalus punctulatus DC (Asteraceae) was analysed by GC and GC–MS. It was shown to consist of about 50 aliphatic esters, together amounting to more than 50% of the oil. 2-Methylbutyl 2-methylpropanoate (21.2%), 2-methylbutyl 2-methylbutanoate (5.6%), 2-methylpropyl 2-methylpropanoate (5.3%), and 7-methyl-2-octyl acetate (4.5%) were the main components. In the terpenoid portion (about 37%), linalyl acetate (4.4%) and α-pinene (1.9%) were the major compounds. In the higher boiling fraction, the artedouglasia oxides A–D, several davanones and laciniata furanones, oxygenated sesquiterpenes previously found in Artemisia species, could be detected in amounts of 5.9%, 0.4% and 1.4%, respectively. Commercial samples of different years showed almost identical compositions