title: Detection of the Previously Unobserved Stereoisomers of Thujone in the Essential Oil and Consumable Products of Sage (Salvia officinalis L.) Using Headspace Solid-Phase Microextraction-Gas Chromatography-Mass Spectrometry.
abstract: The discovery of the (+)-α-thujone and (-)-β-thujone stereoisomers in the essential oil of sage (Salvia officinalis L.) and dietary supplements is documented for the first time. The detection was accomplished using a chiral resolution protocol of racemic α-/β-thujone on headspace solid-phase microextraction-gas chromatography-mass spectrometry. Because the previously unreported stereoisomers, (+)-α-thujone and (-)-β-thujone, are not commercially available, a three-step synthesis of racemic thujone from commercially available starting materials was developed. Thermolysis studies demonstrated that no racemization at the cyclopropane stereocenters occurs, corroborating that the detection is not an artifact from the hydrodistillation process. The developed chiral resolution of thujone was also used to provide evidence for the absence of the (+)-α-thujone and (-)-β-thujone enantiomers in other common thujone-containing essential oils.
authors.affiliation: Department of Chemistry, Mercyhurst University , Erie, Pennsylvania 16546, United States.
authors.forename: Jack D
authors.initials: JD
authors.lastname: Williams
authors.affiliation: Department of Chemistry and Physics, Florida Gulf Coast University , Fort Myers, Florida 33965, United States.
authors.forename: Jessica A
authors.initials: JA
authors.lastname: Yazarians
authors.affiliation: Department of Chemistry and Physics, Florida Gulf Coast University , Fort Myers, Florida 33965, United States.
authors.forename: Chelcie C
authors.initials: CC
authors.lastname: Almeyda
authors.affiliation: Department of Chemistry, Mercyhurst University , Erie, Pennsylvania 16546, United States.
authors.forename: Kristin A
authors.initials: KA
authors.lastname: Anderson
authors.affiliation: Department of Chemistry and Physics, Florida Gulf Coast University , Fort Myers, Florida 33965, United States.
authors.forename: Gregory R
authors.initials: GR
authors.lastname: Boyce
mesh_terms: D000081008:Bicyclic Monoterpenes; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods*; D039821:Monoterpenes / Q000737:chemistry* / Q000302:isolation & purification; D009822:Oils, Volatile / Q000737:chemistry* / Q000302:isolation & purification; D010938:Plant Oils / Q000737:chemistry* / Q000302:isolation & purification; D027543:Salvia officinalis / Q000737:chemistry*; D052617:Solid Phase Microextraction / Q000379:methods*; D013237:Stereoisomerism
chemical_list: D000081008:Bicyclic Monoterpenes; D039821:Monoterpenes; D009822:Oils, Volatile; D010938:Plant Oils; C005790:beta-thujone
keywords: HS-SPME−GC−MS; Salvia officinalis L.; chiral GC−MS; essential oils; thujone