Several of the commercial clary sage oils failed to meet one or more of the European Pharmacopoeia 5.0 (EP 5) specifications for linalool, linalyl acetate, germacrene D or sclareol. The new Himalayan Foothills Oils (Inc.) clary sage oil met all the EP 5 specifications as did the oil from Liberty Natural Products, Oregon. Chiral analyses of linalool and linalyl acetate revealed that the ratio of (-)-R-linalool to total linalool was not very variable, ranging from 73.4% to 83.1%. However, the ratio of (-)-(R)-linalyl acetate to total linalyl acetate was variable with both Russian (82.4%) and Ukrainian (86.5%) oils being clearly different from the other oils that were 99% or more (-)-(R)-linalyl acetate.
Clary sage oil is an important commercial oil obtained from the flowering stems of Salvia sclarea L. It is characterized in the EP 5 as having large amounts of linalool (6.5–24%), linalyl acetate (56–78%) and moderate amounts of germacrene D (1.0–12.0%) and sclareol (0.4–2.6%). Brian Lawrence has reviewed the literature through 2000 and he reported considerable variation in these components. More recently, Carrubba et al. analyzed inflorescences and leaves of an Italian biotype. The oils of the inflorescences and leaves were found to contain large amounts of linalool (28.9% and 25.65%), linalyl acetate (34.9% and 52.7%) and germacrene D (10.6% and 3.9%), with very small quantities of sclareol (0.1% and 0.06%). Analysis of the oil of a Uruguayan biotype of clary sage showed considerable variation based on flowering stages and years: linalool (7.9–22.5%), linalyl acetate (38.6–48.1%), germacrene D (8.2–19.8%) and sclareol (1.1–2.7%). Farkas et al. reported that the clary sage oil from flowers (full bloom) of plants cultivated in Slovak Republic were moderate in linalool (18.9%) and germacrene D (5.0%), but low in linalyl acetate (13.7%) and very high in sclareol (15.7%).
Commercial Kashmir clary sage oil has been analyzed by Shawl et al. who reported it to contain 30% linalool, 52% linalyl acetate and 7.2% alpha-terpineol as major components. The same lab (presumably using the same oil sample) reported that both sclareol and 13-epi-sclareol were present.
Chiral analysis of the major components (linalool and linalyl acetate) of clary sage has been the subject of only a few papers. Casabianca and Graff analyzed French clary sage oil and reported (R)-(-)-linalool (80.6–95.0%):(S)-(+)-linalool (5.0–19.4%) and (R)-(-)-linalyl acetate (93.0–98.1%):(S)-(+)-linalyl acetate (1.9–7.0%).7 Demirci et al. found 76.3% (-)-(R)- and 23.7% (+)-(S)-linalool for locally grown (Turkey) clary sage flower oil.8 They did not report on +/- linalyl acetate. Lorenzo et al. performed chiral analyses on Uruguayan clary sage oil and found (R)-(-)-linalool (72.9%):(S)-(+)-linalool (27.1%) and (R)-(-)-linalyl acetate (99.1%):(S)-(+)-linalyl acetate (0.9%). A review of the literature did not reveal any reports on the chiral analyses of common commercial clary sage oils.
The purpose of this study is to compare both the oil composition and chiral analysis of linalool and linalyl acetate of a new commercial source of Kashmir clary sage oil with other commercially available clary sage oils from various geographic regions.
Other topics discussed: Experimental, Results and Discussion