Submitted to: Phytochemistry Letters
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/17/2011
Publication Date: 6/15/2011
Citation: Cool, L.G., Takeoka, G.R., Vermillion, K. 2011. Volatile non-terpenoid hydrocarbons from Ligusticum grayi roots. Phytochemistry Letters. 4:158-160.
Interpretive Summary: Ligusticum grayi J.M. Coult. & Rose (oshala, Gray’s lovage, Gray’s wild lovage, Gray’s licorice root) is a perennial herb that grows in the Sierra Nevada, Klamath, and Cascade Mountains of California, Nevada, Oregon, and Washington and in similar habitats in Idaho, Montana and westernmost Utah. Roots of this species and the more easterly L. porteri (“osha”) were valued by Native Americans for medicinal purposes and were used to treat colds, coughs, stomachaches. Herbalists currently use the root for similar medicinal treatments and the herb is reported to have anti-bacterial and possibly anti-viral properties. The aromatic roots have a pleasant and distinctive odor. In our continuing efforts to identify biologically active constituents in natural products we studied the chemical composition of L. grayi roots. We identified two non-terpenoid C10 hydrocarbons and a C11 hydrocarbon, viridene. We plan to study the biological activity of these three non-terpenoid hydrocarbons.
Technical Abstract: The root essential oil of Ligusticum grayi Coult. & Rose (Apiaceae) contains three volatile non-terpenoid hydrocarbons: the known C11 compound viridene, whose structure is hereby corrected to 1-[(2Z)-pent-2-en-1-yl]cyclohexa-1,3-diene; and the heretofore unreported C10 compounds 1-[(2Z)-but-2-en-1-yl]cyclohexa-1,3-diene (norviridene) and (Z)-but-2-en-1-ylbenzene (ar-norviridene). These compounds are structurally similar to the 3-alkylphthalides that are widespread in the Apiaceae and, like the latter, probably arise from polyketide precursors.