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Coumarin
Chemical name 1,2-Benzopyrone
2H-1-Benzopyran-2-one
Chemical formula C9H6O2
Molecular mass 146.14 g/mol
Melting point 71 °C
Boiling point 301 °C
Density 0.935 g/cm³ (20 °C)
CAS number 91-64-5
SMILES C1=CC=C2C(=C1)C=CC(=O)O2
Chemical infobox

Coumarin is a chemical compound found in many plants, notably in high concentration in the tonka bean, woodruff, and bison grass. It has a sweet scent, readily recognised as the scent of newly-mown hay. It has clinical value as the precursor for several anticoagulants, notably warfarin. It is also used as a gain medium in some dye lasers.

Synthesis


The biosynthesis of coumarin in plants is via hydroxylation, glycolysis and cyclisation of cinnamic acid. Coumarin can be prepared in a laboratory in a Perkin reaction between salicylaldehyde and acetic anhydride.

The Pechmann condensation provides another synthesis of coumarin and its derivatives.

Derivatives


Some naturally occurring coumarin derivatives include umbelliferone (7-hydroxycoumarin), herniarin (7-methoxycoumarin), psoralen and imperatorin.

Coumarin toxicity


Coumarin is often found in tobacco products and artificial vanilla substitutes, though it has been banned as a food additive in numerous countries since the mid-20th century because it is moderately toxic to the liver and kidneys, with an LD50 of 275 mg/kg - low compared to related compounds. OSHA does not consider this compound to be carcinogenic with the exception of being a lung-specific carcinogen. Coumarin was banned as an adulterant by tobacco companies in 1997 but due to the lack of reporting requirements for pipe tobacco to the US Department of Health and Human Services it was still being used as a flavoring additive in pipe tobacco. Coumarin was banned as a food additive in the United States in 1940, however it was still used in tobacco until 1997. Coumarin is on the Food and Drug Administration's (FDA) Generally Recognized as Safe (GRAS) list as an additive to alcoholic beverages, most notably as an additive to white wines flavored with woodruff, a beverage popular in Germany known as Maiwein. Concerns of coumarin damage to the kidneys and liver may to some extent be associated with coumarin derivatives, many of which are more toxic.

External links


lactones | Fluorescent dyes | Phenylpropanoids

Kumarin | Cumarin | Coumarine | Coumarine | クマリン | Kumaryna

 

This article is licensed under the GNU Free Documentation License. It uses material from the "Coumarin".

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