Essential oil composition and variability of Hypericum perforatum from wild populations of northern Turkey.

Context: Hypericum perforatum L. (Guttiferae) contains many bioactive secondary metabolites including hypericins, hyperforins, and essential oil. Objective: The present study was conducted to determine the variation in composition of essential oil in H. perforatum accessions from Turkey. Material and methods: At full flowering, aerial parts of 30 plants were collected from 10 sites of northern Turkey and assayed for essential oil components by GC-FID and GC-MS. Results: The chemical analysis revealed that the main constituents of the all analyzed samples were hydrocarbon and oxygenated sesquiterpenes such as β-caryophyllene (4.08–5.93%), γ-muurolene (5.00–9.56%), β-selinene (5.08–19.63%), α-selinene (4.12–10.42%), -cadinene (3.02–4.94%), spathulenol (2.34–5.14%), and caryophyllene oxide (6.01–12.18%). Monoterpenes, both hydrocarbon and oxygenated, were represented by scarce amounts of α- and β-pinene, myrcene, linalool, cis- and trans-linalool oxide, and α-terpineol. Principal component analysis was also carried out and, according to the results, the first nine principal components were found to represent 100% of the observed variation. Discussion: The chemical variation among the populations is discussed as the possible result of different genetic and environmental factors. Conclusions: The wild populations examined here are potentially important sources for breeding and improvement of the cultivated varieties. [ABSTRACT FROM AUTHOR]