alpha-Terpinene Chemical Properties

Melting point:

-59.03°C (estimate)

Boiling point:

173-175 °C(lit.)

Density 

0.837 g/mL at 25 °C(lit.)

vapor pressure 

2.22hPa at 25℃

FEMA 

3558 | P-MENTHA-1,3-DIENE

refractive index 

n20/D 1.478(lit.)

Flash point:

115 °F

storage temp. 

2-8°C

solubility 

95% ethanol: soluble1ml/2ml, clear, colorless

form 

Liquid

color 

Clear colorless to light yellow

Specific Gravity

0.84

Odor

at 10.00 % in dipropylene glycol. woody terpene lemon herbal medicinal citrus

Odor Type

woody

Water Solubility 

Soluble in ether, alcohol, and ethanol (100 mg/ml). Insoluble in water.

Merck 

14,9170

JECFA Number

1339

BRN 

1853379

Dielectric constant

2.7000000000000002

Stability:

Light Sensitive

LogP

5.3 at 35℃

EPA Substance Registry System

1,3-Cyclohexadiene, 1-methyl-4-(1-methylethyl)- (99-86-5)

Safety Information

Hazard Codes 

Xn,N,Xi

Risk Statements 

10-22-36/37/38-51/53

Safety Statements 

26-36/37-61-62-36

RIDADR 

UN 2319 3/PG 3

WGK Germany 

2

RTECS 

OS8060000

F 

10-23

TSCA 

Yes

HazardClass 

3.2

PackingGroup 

III

HS Code 

29021990

Toxicity

The acute oral LD₅₀ value in rats was reported as 1.68 g/kg (1*46-1 -90 g/kg) (Moreno, 1973). Because of its action as a liver poison and methaemoglobin former, α-terpinene should be used very sparingly, or not at all, in foods (B?r & Griepentrog, 1967).

MSDS

• Language:English Provider:SigmaAldrich
• Language:English Provider:ACROS

alpha-Terpinene Usage And Synthesis

Chemical Properties

alpha-Terpinene is a clear colorless to light yellow liquid with a woody, terpene, lemon odor with a lemony flavor, becoming bitter at high levels.   It dissolves in ethanol and most non-volatile oils but does not dissolve in water. It is found naturally in oils such as cardamom, sweet oregano, and coriander seed oil.

Occurrence

Reported found in roots, stems, leaves and flowers of Echinacea species. Also reported found in in tea tree oil, papaya fruit, grapefruit, lemon, lime, mandarin, oranage, spearmint, citrus peel oils, cranberry, currants, guava, grapes, raspberry, peach, carrot, celery, cinnamon, clove, cumin seed, ginger, peppermint and corn mint oils, other mentha oils, nutmeg, pepper, mace, parsley, thymus, rum, tea, filberts, pecans, soybeans, passion fruit, beans, sweet marjoram, starfruit, mango, cardamom, coriander seed, origanum, prickly pear, litchi, calamus, dill herb, lovage seed and leaf, juniper berries, laurel, fennel, rosemary, buchu oil, tur meric, sage, nectarines and many other sources.

Uses

It can be used as a chemical fragrance essential oil and spices. It is used as a flavoring and fragrance chemical used in the personal care and cosmetic and food industries. Also used in the pharmaceutical, electronics, food processing, semi-conductor manufacturing industries.

Uses

α-Terpinene is suitable for use in a study to evaluate the antimycotic properties of Melaleuca alternifolia essential oil (tea tree oil, TTO). 1 It is suitable for use to investigate the in vitro antibacterial activity of the essential oils extracted from the fruits of Coriandrum sativum L. and Foeniculum vulgare Miller var. vulgare (Miller).

Production Methods

alpha-Terpinene can be produced
1) by isolation from the Terpene fraction of sweet Orange oil or "Orange terpenes". The title material may constitute as much as 8 to 10% of the total Monoterpenes.
2) by isolation from fractions of American Turpentine oil.
3) from 1-Methyl-4-iso-propylcyclohexadien-1,3-one-2.
4) from Terpinene dihydrochloride with Aniline.

Preparation

May be obtained by isolation from the terpene fraction of sweet orange oil or orange terpenes (8 to 10% of the total monoterpenes); by isolation from fractions of American turpentine oil; from 1-methyl-4-isopropylcyclohexadien-1,3-one-2; also from terpinene dihydrochloride with aniline.

Definition

ChEBI: Alpha-terpinene is one of three isomeric monoterpenes differing in the positions of their two double bonds (beta- and gamma-terpinene being the others). In alpha-terpinene the double bonds are at the 1- and 3-positions of the p-menthane skeleton. It has a role as a volatile oil component and a plant metabolite. It is a monoterpene and a cyclohexadiene.

Aroma threshold values

Aroma characteristics at 10%: citrusy, woody, terpy with camphoraceous and thymol notes; it has spicy and juicy citrus nuances.

Taste threshold values

Taste characteristics at 5 to 100 ppm: terpy, woody, piney, citrus lemon and lime with spice and mint nuances.

General Description

α-Terpinene, a volatile essential oil derived from Melaleuca alternifolia, shows antimicrobial properties against various human pathogens.

Flammability and Explosibility

Flammable

Biochem/physiol Actions

Odor at 10%

Pharmacology

Combinations of terpenes, such as terpinene, with nonionic surfactants and stabilizers have been patented for use as gallstone solvents. Artificial or human cholesterol calculi placed in terpinene with or without human bile at 37°C were dissolved within 1-2 hr (Hisamitsu Pharmaceutical Co., Inc., 1973).

Safety Profile

Moderately toxic by ingestion. When heated to decomposition it emits acrid smoke and irritating fumes.

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