Essential oil variability in Stachys pilifera Benth populations: a narrow endemic species of Iran

Stachys pilifera Benth is an endemic species of Iran where it is found in the mountainous habitats of Zagros region. The plant is a rich source of secondary metabolites endowed with different medicinal properties. Here, for the first time, the essential oil variability among eleven wild populations of S. pilifera, was investigated. Results indicated that the variation of the chemical profile of essential oils was remarkable. The most abundant components were cis-chrysanthenyl acetate (19.1-48.2%), viridiflorol (1.4-19.1%), trans-caryophyllene (2.3-11.9%), caryophyllene oxide (1.9-11.0%), limonene (2.0- 5.9%) and spathulenol (0.0- 9.5). Based on the cluster analyses (CA), four main chemotypes were recognized: chemotype I (cis-chrysanthenyl acetate), chemotype II (cis-chrysanthenyl acetate/viridiflorol), chemotype III (cis-chrysanthenyl acetate/viridiflorol/spathulenol), chemotype IV (cis-chrysanthenyl acetate/trans-caryophyllene/α-pinene). The chemical variation detected can be useful to consider these populations for pharmaceutical industries and industrial applications as well as for domestication and conservation purposes.