Chemical Compositions of Scutellaria Essential Oils Cultivated in Eastern Oregon: S. angustifolia, S. baicalensis, S. barbata, and S. lateriflora.

The genus Scutellaria (Lamiaceae) is a phytochemically rich and medicinally important group of plants. Scutellaria species have been characterized by biologically active flavonoids such as baicalin, baicalein, and wogonin. In the present study, the essential oils of S. angustifolia, S. baicalensis, S. barbata, and S. lateriflora, cultivated in eastern Oregon, were obtained by means of hydrodistillation and analyzed using gas chromatographic methods. We hypothesize that the essential oils have compositions that may play a role in the traditional uses and biological activities of the genus. The major components in S. angustifolia essential oils were germacrene D (32.5-58.3%), (E)-β-caryophyllene (4.9-29.2%), and β-bourbonene (2.8-9.4%). Scutellaria barbata essential oil was dominated by 1-octen-3-ol (59.9%), with lower concentrations of linalool (9.5%) and (2E)-hexenal (5.1%). The major components in the essential oil of S. lateriflora were 1-octen-3-ol (28.3%), acetophenone (24.8%), benzaldehyde (7.5%), limonene (6.0%), (E)-benzalacetone (5.9%), and β-phellandrene (5.1%). The major components of the essential oil of S. baicalensis were 1-octen-3-ol (22.3%), (E)-β-caryophyllene (22.3%), and germacrene D (28.3%). This study demonstrates that Scutellaria can be cultivated in eastern Oregon. Additionally, S. angustifolia essential oil has been characterized for the first time.