Absorption, Distribution and Excretion
... After iv injection of 0.1 mL/kg, death due to massive pulmonary edema occurred within minutes. In this animal blood and tissue levels of alpha-terpineol of between 150 and 300 ppm were observed. After smaller doses of pine oil (0.033 mL/kg), horses survived until euthanized up to 48 hr later. Blood levels of alpha-terpineol became undetectable in one of these animals after 2 hr, and no tissue levels were detected at postmortem....

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Metabolism / Metabolites
The metabolic fate of alpha-terpineol administered orally to male albino-rats was investigated, and its effects on the liver microsomal cytochrome-P-450 system were studied. For metabolic studies, alpha-terpineol was given once daily for 20 days at a dose of 600mg/kg bw; cytochrome-P-450 studies involved dosing for up to 9 days. ...The neutral fraction isolated showed the presence of one major (alpha-terpineol) and two minor compounds. One of the minor compounds was identified as p-menthane-1,2,8-triol. Further study revealed the presence of the methyl esters of oleuropeic-acid and dihydrooleuropeic-acid. Allylic oxidation of C-1 methyl esters appeared to be the major metabolic pathway. It was considered likely that the allylic methyl group at C-7 was oxidized prior to the reduction of the 1,2-double bond. Administration of alpha-terpineol increased the levels of liver microsomal cytochrome-P-450 by 72, 104, 90, 54, and 52% after 1, 2, 3, 6, and 9 days of dosing, respectively. A moderate incr was noted in the levels of liver microsomal NADPH-cytochrome-c-reductase during the first 3 days of repeated dosing. No significant effect was noted on cytochrome-b5 and NADH-cytochrome-c-reductase. The authors conclude that the allylic methyl oxidation of alpha-terpineol is the major route for its metabolic transformation in the rat. The reduction of the endocyclic double bond was specifically noted in the formation of dihydrooleuropeic-acid from oleuropeic-acid.
Biotransformation of alpha-terpineol by the common cutworm (Spodoptera litura) larvae was investigated. alpha-Terpineol was mixed in an artificial diet, and the diet was fed to the larvae (fourth-fifth instar) of S. litura. Metabolites were isolated from the frass and analyzed spectroscopically. Main metabolites were 7-hydroxy-alpha-terpineol (p-menth-1-ene-7,8-diol) and oleuropeic acid (8-hydroxy-p-menth-1-en-7-oic acid). Intestinal bacteria from the frass of larvae did not participate in the metabolism of alpha-terpineol. alpha-Terpineol was preferentially oxidized at the C-7 position (allylic methyl group) by S. litura larvae.
Details of the metabolism of alpha-terpineol by Pseudomonas incognita are presented. Degradation of alpha-terpineol by this organism resulted in the formation of a number of acidic and neutral metabolites. Among the acidic metabolites, beta-isopropyl pimelic acid, 1-hydroxy-4-isopropenyl-cyclohexane-1-carboxylic acid, 8-hydroxycumic acid, oleuropeic acid, cumic acid, and p-isopropenyl benzoic acid have been identified. Neutral metabolites identified were limonene, p-cymene-8-ol, 2-hydroxycineole, and uroterpenol. ... /I/t appears that P. incognita degrades alpha-terpineol by at least three different routes. While one of the pathways seems to operate via oleuropeic acid, a second may be initiated through the aromatization of alpha-terpineol. The third pathway may involve the formation of limonene from alpha-terpineol and its further metabolism.
In a minor pathway, the endocyclic alkene of alpha-terpineol is epoxidized and then hydrolysed to yield a triol metabolite 1,2,8-trihydroxy- para-menthane, which was also reported in humans after inadvertent oral ingestion of a pine-oil disinfectant containing alpha-terpineol.
Metabolized primarily by conjugation with glucuronic acid and excreted in urine. Oxidation of the allylic methyl group followed by hydrogenation to yield the corresponding saturated acid may occur.

Toxicity Summary
IDENTIFICATION AND USE: alpha-Terpineol is a colorless solid. It used in perfumes manufacturing; denaturing fats for soap manufacture; hydrocarbon solvent; solvent for resins, cellulose esters, and ethers; disinfectants; antioxidants; medicines; constituent of flavorings. It is not registered for current pesticide use in the U.S., but approved pesticide uses may change periodically and so federal, state and local authorities must be consulted for currently approved uses. HUMAN EXPOSURE AND TOXICITY: In human subjects, alpha-terpineol had a low irritative potency but a strong odor. Two dermatitis patients were reported to be sensitized to alpha-terpineol, although attempts to induce skin sensitization in volunteers using a dilute solution of alpha-terpineol were unsuccessful. Two fatalities described in the literature were both due to accidental ingestion of a pine oil-containing products and were attributed to combined toxicity of isopropanol and 1-alpha-terpineol. The regulatory properties of the essential oil of Melaleuca alternifolia (tea tree oil) on the production of oxygen derived reactive species by human peripheral blood leukocytes activated in vitro was evaluated and found that alpha-terpineol significantly suppressed fMLP-, LPS- and PMA-stimulated superoxide production; suggesting the potential for selective regulation of cell types by these components during inflammation. ANIMAL STUDIES: In rabbits neat alpha-terpineol was a moderate skin irritant. Following acute oral exposure, a low toxicity was generally reported in rodents. Acute toxicity of pine oil (a commercially available disinfectant) after intravenous administration in horses was studied. alpha-Terpineol was identified as a major constituent of pine oil. alpha-Terpineol was recovered from equine tissues after iv injection of 0.1 mL/kg, death due to massive pulmonary edema occurred within minutes. Indirect evidence of liver effects was seen in rats given repeated oral doses. No indication of lung carcinogenicity was seen in a limited study in mice (treated by injection). Terpineol caused a slight but dose-related increase in the number of his+ revertants with Salmonella TA102 tester strain both without and with activation. The effects of terpineol on the compound action potential (CAP) of rat sciatic nerve were studied. Terpineol induced a dose-dependent blockade of the CAP.

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Toxicity Data
LC50 (rat) > 4,760 mg/m3/4hr

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Non-Human Toxicity Values
LD50 Rat oral 5170 mg/kg
LD50 Mouse oral 12,080 ug/kg
LD50 Mouse im 2000 mg/kg
LD50 Mouse (CD-1, male) oral 2830 mg/kg (95% C. I., 2290-3497 mg/kg)

[1]. Antimicrobial effect of linalool and α-terpineol against periodontopathic and cariogenic bacteria. Anaerobe. 2012 Jun;18(3):369-72.

[2]. Effect of citral, eugenol, nerolidol and alpha-terpineol on the ultrastructural changes of Trichophyton mentagrophytes. Fitoterapia. 2009 Jul;80(5):290-6.

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.
alpha-TERPINEOL has been reported in Camellia sinensis, Callistemon citrinus, and other organisms with data available.
2-(4-Methyl-3-cyclohexen-1-yl)-2-propanol is a metabolite found in or produced by Saccharomyces cerevisiae.
See also: Coriander Oil (part of); Peumus boldus leaf (part of); Cannabis sativa subsp. indica top (part of).

C10H18O

154.2493

154.135

98-55-5

68540-43-2 (hydrochloride salt)

17100

White to off-white solid powder

0.9±0.1 g/cm3

217.5±0.0 °C at 760 mmHg

31-34ºC

89.4±0.0 °C

0.0±0.9 mmHg at 25°C

1.483

2.79

1

1

1

11

168

0

WUOACPNHFRMFPN-UHFFFAOYSA-N

InChI=1S/C10H18O/c1-8-4-6-9(7-5-8)10(2,3)11/h4,9,11H,5-7H2,1-3H3

2-(4-methylcyclohex-3-en-1-yl)propan-2-ol

2934.99.9001

Powder      -20°C    3 years

                     4°C     2 years

In solvent   -80°C    6 months

                  -20°C    1 month

Room temperature (This product is stable at ambient temperature for a few days during ordinary shipping and time spent in Customs)

DMSO : ≥ 250 mg/mL (~1620.75 mM)

Solubility in Formulation 1: ≥ 2.08 mg/mL (13.48 mM) (saturation unknown) in 10% DMSO + 40% PEG300 + 5% Tween80 + 45% Saline (add these co-solvents sequentially from left to right, and one by one), clear solution.
For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 20.8 mg/mL clear DMSO stock solution to 400 μL PEG300 and mix evenly; then add 50 μL Tween-80 to the above solution and mix evenly; then add 450 μL normal saline to adjust the volume to 1 mL.
Preparation of saline: Dissolve 0.9 g of sodium chloride in 100 mL ddH₂ O to obtain a clear solution.

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Solubility in Formulation 2: ≥ 2.08 mg/mL (13.48 mM) (saturation unknown) in 10% DMSO + 90% (20% SBE-β-CD in Saline) (add these co-solvents sequentially from left to right, and one by one), clear solution.
For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 20.8 mg/mL clear DMSO stock solution to 900 μL of 20% SBE-β-CD physiological saline solution and mix evenly.
Preparation of 20% SBE-β-CD in Saline (4°C，1 week): Dissolve 2 g SBE-β-CD in 10 mL saline to obtain a clear solution.

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Solubility in Formulation 3: ≥ 2.08 mg/mL (13.48 mM) (saturation unknown) in 10% DMSO + 90% Corn Oil (add these co-solvents sequentially from left to right, and one by one), clear solution.
For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 20.8 mg/mL clear DMSO stock solution to 900 μL of corn oil and mix evenly.

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 (Please use freshly prepared in vivo formulations for optimal results.)