Definition
ChEBI: A chromenone having the keto group located at the 2-position.
General Description
Colorless crystals, flakes or colorless to white powder with a pleasant fragrant vanilla odor and a bitter aromatic burning taste.
Reactivity Profile
COUMARIN(91-64-5) is sensitive to exposure to light. COUMARIN(91-64-5) is also sensitive to heat. This chemical is incompatible with strong acids, strong bases and oxidizers. COUMARIN(91-64-5) is hydrolyzed by hot concentrated alkalis. COUMARIN(91-64-5) can be halogenated, nitrated and hydrogenated (in the presence of catalysts).
Air & Water Reactions
Insoluble in water.
Hazard
Toxic by ingestion; carcinogenic. Use in
food products prohibited (FDA). Questionable carcinogen.
Health Hazard
SYMPTOMS: Exposure to this compound may cause narcosis. It may also cause irritation and liver damage.
Fire Hazard
This chemical is combustible.
Description
Coumarin is a naturally occurring Benzopyrone compound.
It is found in a large number of plants belonging to many
different families including tonka beans, woodruff, lavender
oil, cassia, melilot (sweet clover), and other plants. It is found
in edible plants such as strawberries, cinnamon, peppermint,
green tea, carrots, and celery, as well as in partially fermented
tea, red wine, beer, and other foodstuffs. Concentrations range
from 87 000 ppm in cassia and 40 000 ppm in cinnamon to
20 ppm in peppermint and 5 ppb in tangerines.
Occurrence
Found in many plants and essential oils such as cassia, melilot, orchid, lavender and balsam of Peru (Sp?th, 1937; Gildemeister & Hoffman, 1966).
Preparation
Coumarin is currently produced by Perkin synthesis from salicylaldehyde.
In the presence of sodium acetate, salicylaldehyde reacts with acetic
anhydride to produce coumarin and acetic acid. The reaction is carried out in the
liquid phase at elevated temperature.
A process for the production of coumarin from hexahydrocoumarin by dehydrogenation has also been elaborated.
Since the odor of coumarin is relatively weak, strong-smelling by-products (e.g.,
vinylphenol) must be removed. Many purification methods have been reported
and patented.
Aroma threshold values
Detection at 34 to 50 ppb; recognition, 250 ppb
Flammability and Explosibility
Nonflammable
Biological Activity
Oral anticoagulants can be prepared from compounds with coumarin as a base. Coumarin has been known for well over a century and, in addition to its use pharmaceutically, it is also an excellent odor-enhancing agent. However, because of its toxicity, it is not permitted in food products in the United States (Food and Drug Administration). One commercial drug is 3-(alpha-acetonyl-4-nitrobenzyl)- 4-hydroxycoumarin. This drug reduces the concentration of prothrombin in the blood and increases the prothrombin time by inhibiting the formation of prothrombin in the liver. The drug also interferes with the production of factors VII, IX, and X, so that their concentration in the blood is lowered during therapy. The inhibition of prothrombin involves interference with the action of vitamin K, and it has been postulated that the drug competes with vitamin K for an enzyme essential for prothrombin synthesis. Another commercial drug is bis-hydroxy-coumarin, C19H12O6. The actions of this drug are similar to those just described.
Synthesis
May be extracted from tonka beans; from salicylaldehyde and acetic anhydride in the presence of sodium acetate; also
from o-cresol and carbonyl chloride followed by chlorination of the carbonate and fusion with a mixture of alkali acetate, acetic
anhydride and a catalyst.
Environmental Fate
Coumarin toxicity is a function of blood and target tissue levels
of coumarin relative to the metabolic capacity of the target
organ. Cellular toxicity results when the formation of the toxic
moieties exceeds the capacity of the cell to detoxify. This can
have significant impact when comparing dosing by gavage to
dietary exposure.
Purification Methods
Coumarin crystallises from ethanol or water and sublimes in vacuo at 43o [Srinivasan & deLevie J Phys Chem 91 2904 1987]. [Beilstein 17/10 V 143.]
Toxicity evaluation
Coumarin is readily biodegradable. Coumarin is unlikely to
bind to soil. Coumarin does not bioaccumulate; the bioconcentration
factor has been determined to be <10–40.
Various environmental fate studies have shown that coumarin
in the environment would biodegrade and be lost to volatilization.
Losses resulting from photolysis may also occur.
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