When we talk about Clary Sage Oil, a precious essential oil extracted from the flowers and leaves of the Salvia sclarea plant in the family Lamiaceae through steam distillation, we cannot ignore its core soul components - Linalyl acetate and Linalool. Clary Sage Oil is a light yellow to orange liquid at room temperature, emitting a pleasant, complex aroma with herbal, light, woody, spicy, and subtle citrus notes. The key to its unique charm lies in its high content of esters and alcohol compounds.
Note: The ester alcohol equilibrium between linalool (C₁₀H₁₈O) and linalyl acetate (C₁₂H₂₀O₂) is the molecular basis for the aroma stratification of Clary Sage Oil.
It is worth mentioning that the content of linallyl acetate in Clary Sage Oil is particularly prominent, typically ranging from 34% to 77%. Linalyl acetate itself can hydrolyze and release free linalool under acidic or enzymatic action. Meanwhile, Clary Sage Oil also contains a certain proportion of linalool and linalyl acetate, which together form the chemical basis for its aroma and efficacy. Therefore, understanding linalool is a crucial step in gaining a deeper understanding of the value of Clary Sage Oil.
Linalool, also known as 3,7-dimethyl-1,6-octadien-3-ol, is a monoterpene alcohol compound. It is also known as Chenxiangchun, Yansuichun. In addition, Linalool has two enantiomers: (+) - R-linalool and (-) - S-linalool
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(+) - R type: with a rosewood aroma, found in coriander seeds and sweet oranges; (-) - S type: with lavender fragrance, dominant lavender and perilla oil aromas. Fragrance application tip: The proportion of isomers directly affects the odor of natural essential oils. |
Basic Properties&Aroma:
Appearance: Colorless and flammable liquid that flows easily.
Odor: Its aroma is described as a "strong green with a sweet woody scent", similar to the aroma of rosewood. It blends the floral scents (lilac, lily of the valley, and rose) with woody and fruity notes. The overall feeling is soft, light, and translucent. However, its aroma has a relatively short persistence(<2 hours).
Physical properties: Melting point of about 20°C, boiling point of about 198°C, density between 0.85g/cm³-0.86g/cm³. It is slightly soluble in water (about 1.589 g/L), has a low flash point (about 55-78°C), and is classified as flammable.
Natural Sources&Occurrences:
Linalool is one of the most widely distributed spice components in nature, naturally present in over 200 plant species. It is a major or important component of many plant essential oils, including:
- Rosewood oil, Galois oil (main source)
- Cilantro seed oil, Blancpain leaf oil, lavender oil, bergamot oil
- Clary Sage Oil (as mentioned earlier, as a hydrolysis product and direct component)
- Thymus essential oil (the content varies with varieties, for example, about 6% in wild Thymus serpyllum)
Extraction&Production:
There are two main ways to obtain Linalool:
1. Natural Extraction: Natural linalool is isolated by distilling natural essential oils rich in linalool, such as camphor oil and rosewood oil.
Fractional distillation: Separation from camphor oil/rosewood oil requires temperature control of 198 ± 2°C to preserve thermosensitive structures;
Supercritical CO ₂ extraction: Low temperature retention of all components, yield increase of 12% -15%, but higher cost.
2. Chemical synthesis: This is currently the main method for large-scale production. There are four synthetic processes, usually using turpentine (mainly containing α-pinene or β-pinene) as the raw material.
2.1 Roche method: using acetylene and acetone as raw materials, with metallic sodium and liquid ammonia as important intermediate materials. Although there are many synthesis steps and certain safety risks, the production cost is low. This method is mainly adopted by XinheCheng and Disiman Company.
2.2 BASF method: a unique process route developed by BASF with high commercial value. Intermediate products can generate isoprene, thereby expanding another series of products. This method has a low production cost, but requires the separation of intermediates.
2.3 Isobutene method: It may have lower production costs, but it faces higher environmental risks. The Japanese Kuraray クラレトレーディング株式会社 mainly adopts this method.
2.4 β-Pinene method: BBA (later acquired by IFF) in the UK mainly uses this method. This method synthesizes laurene from β-pinene, and the hydrogen halide of laurene leads to the formation of coumarin, linalool, and linalool chlorides. The mixture reacts with copper chloride to obtain linalyl acetate. Linalool and nerolidol can be obtained through separation and saponification reactions.
The synthesis process can efficiently produce linalool to meet different needs. Please contact us for more details. (Email: sales@appchem.cn)