Chemical Characterization of Three Artemisia tridentata Essential Oils and Multivariate Analyses: A Preliminary Investigation

Abstract

Background/Objective: Big sagebrush ( Artemisia tridentata Nutt., Asteraceae) is a conspicuous shrub growing in arid and semi-arid regions of intermountain western North America, from eastern Washington and Oregon, through Nevada, Idaho, and Utah, into northern Arizona and New Mexico, and east as far as the western Dakotas, and Colorado. At least three subspecies of A. tridentata have been recognized, including A. tridentata subsp. tridentata Nutt. (basin big sagebrush), A. tridentata subsp. wyomingensis Beetle & A.L.Young (Wyoming big sagebrush), and A. tridentata subsp. vaseyana (Rydb.) Beetle (mountain big sagebrush). Although big sagebrush is an important food source and cover for several animal species, the volatile phytochemistry has shown wide variation in composition. The purpose of this work was to compare and contrast the essential oil compositions of the three subspecies of A. tridentata growing in southwestern Idaho. Methods/Results: Several samples of A. tridentata subsp. wyomingensis and A. tridentata subsp. vaseyana were collected, the essential oils obtained by hydrodistillation using a Likens-Nickerson apparatus in yields of 2.33%-4.45% and 0.90%-1.73%, respectively, and the essential oils analyzed by gas chromatographic techniques. Although A. tridentata shows wide variation in essential oil compositions, multivariate analysis (hierarchical cluster analysis and principal component analysis) indicated A. tridentata subsp. tridentata to be characterized by high concentrations of yomogi alcohol (5.8%-30.8%) and camphor (5.2%-20.1%), while camphor was the defining component in A. tridentata subsp. wyomingensis (10.0%-30.1%) and subsp. vaseyana (16.1%-40.2%). One sample of A. tridentata subsp. vaseyana was dominated by α-thujone (76.1%), however. Conclusion: There is much variation in essential oil compositions of A. tridentata, both within subspecies and between geographical locations; much additional investigation is necessary to more fully characterize the volatile phytochemistry of this plant.

The essential oil characterization of Achillea millefolium var. occidentalis DC. from the Great Basin of North America

“…However, there are no obvious trends in the enantiomeric distribution of monoterpene hydrocarbons or of oxygenated monoterpenoids in the family [59]. When detected, (-)-(E)-β-caryophyllene is the only enantiomer observed [60][61][62]. This enantiomer is found in numerous higher plants, while (+)-(E)-β-caryophyllene is apparently found in liver-worts [13].…”

The Essential Oil Compositions of Ambrosia acanthicarpa Hook., Artemisia ludoviciana Nutt., and Gutierrezia sarothrae (Pursh) Britton & Rusby (Asteraceae) from the Owyhee Mountains of Idaho

“…vaseyana (Rydb.) Beetle [ 47 ]. Limonene enantiomers were variable in A. ludoviciana (this work), but (+)-limonene was dominant in Artemisia arborescens L. [ 48 ] and (−)-limonene was dominant in A. annua [ 46 ].…”

“…wyomingensis Beetle & A.L. Young [ 47 ]. However, (−)-α-terpineol was the dominant enantiomer in A. tridentata subsp.…”

“…wyomingensis and A. tridentata subsp. vaseyana from Idaho, USA [ 47 ]. Although (−)-borneol was the only enantiomer observed in A. ludoviciana (this work) and A. tridentata subsp.…”

“…wyomingensis and subsp. vaseyana [ 47 ], (+)-borneol was the dominant enantiomer in A. arborescens [ 48 ].…”