Terpineol

Terpineol naturally occurs in pine oil, lavender oil, gallo oil, orange leaf oil, neroli oil and other essential oils. Turpentine is a kind of fragrance obtained through the hydration of α-pinene olefin or β-pinene to generate hydrated terpene glycol, followed by dehydration and fractionation. Terpineol is one of the earliest synthetic fragrances to achieve industrial production. It is mainly used as soap essence, and it has been more than 100 years old. Terpineol is a bulk spice products with a world annual output of thousands of tons. It is used in a wide variety of cosmetic formulations, especially in the formulation of soaps and synthetic detergents, up to 30%. IFRA has no restrictions.
Figure 1 shows the chemical reaction equation of the α-pinene terpineol.
Terpineol has the aroma of pine and lilac. It appears as a viscous liquid, but easy to subject to crystallization with the boiling point of 218 ~ 219 ℃, 85 ℃ / 400Pa, the melting point of 35 ℃ (α-terpineol). Mainly used to deploy lilac, lily of the valley, Acacia, orange blossom and other scented soap, cosmetics flavor. Pure α-terpineol can still be used for preparation of lemons, oranges, peaches and other food flavors. A lot of ester compounds prepared from terpineol are also excellent spices.

Terpineol has α, β, and γ three isomers. Based on their melting points, they should all belong to solid. However, the most marketing synthetic products are the mixture of these three isomers, appearing as liquid.
Alpha-terpineol has dextrorotatory, levorotatory and racemic 3 types. Right-handed alpha-terpineol naturally occurs in cardamom oil, orange oil, orange leaf oil, neroli oil, jasmine oil, nutmeg oil; levorotatory α-terpineol naturally occurs in pine needle oil, camphor oil, Leaf oil, lemon oil, lime oil, rosewood oil. Beta-terpineol has cis and trans isomers (rare in essential oils). γ-Terpineol is present in the form of free-form or ester in juniper wood oil.
Alpha-terpineol-based mixture is used in the spice. It appears as colorless viscous liquid. It has a unique clove aroma. The boiling point of 214 ~ 224 ℃, the relative density of d25250.930 ~ 0.936. Refractive index nD201.482 ~ 1.485. Insoluble in water, soluble in ethanol, propylene glycol and other organic solvents. α-terpineol exists in more than 150 kinds of plant leaves, flowers, grass stems. d-Polarimetry exists in cedar, cardamom, star anise, orange blossom and other essential oils. l-Polarimetry exists in miscellaneous lavender, Melaleuca, white lemon, cinnamon leaves and other essential oils.

Figure 2 for terpineol α, β, γ three isomers of the chemical structure

Pine oil is a products consisting of α-terpineol-based monoterpene alcohols and monoterpenes. Pine oil is light yellow to reddish brown oily liquid, being slightly soluble in water with a special odor. It has a strong bactericidal ability, good wetting, cleaning and permeability, being easily saponified or emulsified by other surfactants. It has good resistance to oils, fats and greases.

Ingredients: The main oxygenates include α-terpineol, β-terpineol, γ-terpineol, α-fenchol, borneol, isoborneol, camphor, terpinen-1, terpinene alcohol-4, dioxanone alcohol, methyltyrosol, anethole, 1,4-eucalyptol, 1,8-eucalyptol and so on. The major terpene components include terpinolene, limonene, alpha-terpinene, gamma-terpinene, para-methyl ene-2, 4 (8), para-cymene and sesquiterpenes. Synthetic pine oil contains much terpinolene, and does not contain anethole and methyl chelating phenols, traces of camphor. Steam distilled pine oil contains higher borneol and anethole.

Figure 3 the main component of synthetic pine oil
Uses: A large number of pine oil is used as a flotation agent for mineral flotation (copper, lead and zinc ore and other non-ferrous metal ores), but also as a printing and dyeing auxiliaries, pigment humectants, paints anti-skinning agent, sheep skin degreasing agents, Epoxy leveling agents, anti-foaming agents for protein compounds in plywood industries, animal blood preservatives, and leveling agents in baking paints, paper coatings and enamels.

According to the data provided by RIFM, acute toxicity data of terpineol: oral LD50 4.3g / kg (rat), skin test LD50> 3g / kg (rabbit).

Terpineol is divided into spice specifications and medicinal specifications; spice-grade terpineol has good aroma adaptability and good stability in the air and many aroma media, being widely used in a variety of purposes flavor formula. Meanwhile, it can be used to increase the fresh aroma; as the body fragrance, it is commonly used in incense lily, lilac, lily of the valley, acacia, rhodiola rosea, orange blossom; also important spice in magnolia, gardenia, narcissus and pine needle flavor. Terpineol is inexpensive and is widely used for blending advanced fragrances such as soap and cosmetic fragrances as well as lilac-like high-grade flavor and is used in the pharmaceutical, motor, ink and other industries. Fraction containing alcohol content of 40% to 80% is called synthetic pine oil, mainly used for flotation foaming agent of non-ferrous metal.

Figure 4 Quality indicators of the medicinal terpineol and spice terpineol

The weight ratio of turpentine and 30% sulfuric acid ingredients is 1: 1.7 with 10% Pergal as emulsifier. The reaction temperature is 28-30 ℃. The reaction was allowed to stand for 24 hours and then stratified. The resulting hydrated terpene glycol crystals floated on the acid water; after removal of the acid water, the remained crystal and oil layer in the reaction pot was washed with water by 3 times; use dilute alkali to wash to neutral pH; apply rejection centrifuge to obtain hydrated terpene glycol crystal. 
The weight ratio of hydrated terpene glycol and 0.2% sulfuric acid ingredients is 1: 2; stir and send direct steam and indirect steam to heat to boiling; the reaction takes about 3 to 5 hours and ended until the specific gravity reached d204 0.933. Apply stand stratification and discharge the lower acid. Turbid layer is neutralized by dilute alkaline; remove the alkaline; stand for clarification; the oil layer is subject to fractionation and fractionally collected according to the proportion of distillate fraction; the finished or semi-finished product has a output of terpineol being 55% to 60%.

Terpineol is a monoterpene alcohol that has been found in a variety of plants, including Cannabis, and has diverse biological activities. Terpineol contains the four isomers α-, β-, and γ-terpineol and terpinen-4-ol. α-Terpineol has antibacterial and antinociceptive properties. It is active against a variety of periodontopathic and cariogenic bacteria, including strains of P. gingivalis, F. nucleatum, and A. actinomycetemcomitans (MICs = 0.1-0.8 mg/ml), however, it is toxic to KB cells when used at a concentration of 0.8 mg/ml. It also reduces mechanical hyperalgesia, as well as spontaneous and palpation-induced nociception, in a mouse model of cancer-induced pain beginning on day 5 when administered at a dose of 50 mg/kg per day. Terpinen-4-ol has anticonvulsant properties, inhibiting pentylenetetrazol-induced seizures in mice when used at doses ranging from 50 to 200 mg/kg. α-Terpineol and terpinen-4-ol also have anti-inflammatory properties, reducing LPS-induced production of IL-1β, IL-6, and IL-10, but not TNF-α, in U937 cells. This product is a mixture of α-, β-, and γ-terpineol.

It appears as colorless liquid or low-melting transparent crystal with a clove flavor. 1 part of terpineol can be dissolved in 2 parts (volume) of 70% ethanol solution, being slightly soluble in water and glycerol.

Reported to be found in more than 200 derivatives from leaves, herbs and flowers [Fenaroli 's Handbook of Flavor Ingredients, 1971 ; Gildemeister & Hoffman, 1962).

Solvent for hydrocarbon materials, mutual solvent for resins and cellulose esters and ethers, perfumes, soaps, disinfectant, antioxidant, flavoring agent.

Terpineol is a monoterpene alcohol with potential antifungal, antioxidant and antiproliferative activities. This product is a mixture of isomers.

From terpin hydrate by the splitting off of the elements of water by chemical means (Bedoukian, 1967).

ChEBI: Alpha-terpineol is a terpineol that is propan-2-ol substituted by a 4-methylcyclohex-3-en-1-yl group at position 2. It has a role as a plant metabolite.

α-Terpineol is a cyclic monoterpene. It is one of the major monoterpenol component of the cultivar Gewürztraminer and other aroma-rich grape varieties. α-Terpineol, a monoterpenoid alcohol, has been investigated for its anticonvulsant activity. It was one of the insecticidal constituent of the essential oils of Dahlia pinnata.FCC includes the following isomers in the listed purity: alpha-, (E)-beta, (Z)-beta, gamma-, terpinen-4-ol, and terpinen-1-ol.