Submitted to: Journal of Essential Oil Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/15/2007
Publication Date: 3/1/2008
Citation: Takeoka, G.R., Dao, L.T., Rodriguez, D.M., Patterson, R. 2008. Headspace Volatiles of Scutellaria californica A. Gray Flowers. Journal of Essential Oil Research. 20:169-171. Interpretive Summary: Plants of the Scutellaria L. (Lamiaceae) genus are widely distributed throughout the world and are represented by about 300 species. These plants are used in traditional and folk medicine for the treatment of hypertension, arteriosclerosis, inflammatory diseases, neuralgia, insomnia, nervous tension states, hepatitis, allergy, cancer and diarrhea. Extracts and constituents of Scutellaria spp. have been reported to have sedative, antioxidant, antithrombotic, antispasmodic, antimicrobial and antiviral properties. Previous studies on these plants have revealed that non-volatiles such as flavonoids, iridoids, tannins, lignins, diterpenes and triterpenes are present in different parts of the plant. There are a few reports on the antimicrobial activity of the essential oils obtained from the distillation of aerial parts of Scutellaria plants. In our continuing search for biologically active natural constituents, we investigated the volatiles in S. californica flowers. To our knowledge, this is the first report on the volatile constituents of Scutellaria spp. flowers. We identified a total of 52 constituents in S. californica flowers. Our next step is to study the biological activity of the identified constituents.
Technical Abstract: Volatile constituents of California skullcap (Scutellaria californica A. Gray) flowers were isolated by solid-phase microextraction (SPME) and analyzed by GC and GC/MS. A total of 52 constituents were identified (constituting 90.79% of the total area), 12 of which were tentatively identified. Caryophyllene (56.61%), germacrene D (6.89%), methyl 2- methylbutanoate (4.87%), beta-bourbonene (4.49%), alpha-humulene (2.76%), methyl butanoate (2.74%), and alpha-copaene (1.52%) were the major constituents of the flower volatiles. Due to their low odor thresholds (measured in water) and fruity aroma, methyl 2-methylbutanoate (4.87%; odor threshold = 0.1 ppb) and ethyl 2-methylbutanoate (0.72%; odor threshold = 0.007 ppb) were considered to be important contributors to the characteristic sweet, apple-like odor of these flowers.