Coumarins

Other Names Benzopyrones, coumarine· cumarines, kumarine Empirical formula: C9H60 2 (= 1,2-benzopyrone) Substance type: benzopyrone Coumarin (= chromen-2-on, kumarin, 2H-1benzopyran- 2-on, o-cumar[in] acid lactone), which has a scent like that of vanilla, crystallizes into colorless prisms and is easily soluble in alcohol, ether, and essential oils. Pure coumarin is exuded from what are known as tonka beans, and for this reason it is also called tonka bean camphor. Coumarin is biosynthesized by the hydroxylation of cinnamic acid or coumarin glycoside. Even plants that do not actually contain any coumarin often produce it when they wilt (giving off the smell of hay) or dry (e.g., Anthoxanthum odoratum, Galium odoratum, Sida acuta). Coumarins in Psychoactive Plants (from Gray and Waterman1978; Rompp 1995*; Shoeb et ai. 1973; supplemented) Coumarins (e.g., benzofuran) have been found in the following plants with demonstrated or purported psychoactivity: Aegle marmelos Corr. coumarin Anthoxanthutn odoratumL.(sweetvernal grass) coumarin Dipteryx (Coumarouna) odorata (AubI.) Willd. coumarin Dipteryxoppositifolia (Aubl.) .Willd. (tonka bean) coumarin Evodia spp. (cf. Evodia bonwickii) coumarin Galiumodoratum(L.}Scop.(woodruff) [syn. Asperula odorata 1.] coumarin Hierochloe australis (1.) P. Beauv. (buffalo grass; vodka additive) coumarin Flierochloe odorata (L.) P. Beauv. (sweet grass, vanilla grass; cf. incense) unidentified Justicia pectoralis coumarin and others Laval1dula angustifolia Mill. [syn. Lavandula officinalis Chaix] (c£ essential oils) coumarin and others Melilotus officinalis (1.) Pall. various Melilotus spp. (sweet clover) furanocoumarins Petroselinum crispum rutin, gravolenic acid Rutagraveolens 1. (cf. haoma, soma) coumarin Sida acuta coumarin Sidaspp. various Tagetes spp. various Thamnosma montana   For plants containing the coumarin derivative scopoletin, see scopoletin.   Umbelliferone, aesculine, and furocoumarin are all coumarin derivatives. More than six hundred natural coumarins are now known. About two hundred coumarins occur in the Family Rutaceae (including the genera Zanthoxylum, Evodia, Ruta, Thamnosma, Dictamnus, Eriostemon, Citrus, and Aegle), where they appear to have great chemotaxonomic importance (Gray and Waterman 1978; Tatum and Berry 1979). Coumarins occur in some plants that are used for psychoactive purposes (see scopoletin). Coumarin is the substance responsible for the specific taste of woodruff punch, and it is also present in fahan tea (Angraecum fragrans Du Petit-Thouars), which Bibra (1855*) described as psychoactive. Fahan was once used as a substitute for green tea (Camellia sinensis) and was mixed with tobacco (Nicotiana tabacum) and rolled into cigars (Frerichs et al. 1938, 1234*). High dosages of pure coumarin can cause headaches, dizziness, lethargy, stupor, and even respiratory paralysis (Roth et al. 1994, 796*). Coumarin is said to be toxic to the liver and for this reason was banned as a component or ingredient in food. However, the toxicity is very doubtful, and the alleged carcinogenic effects are also questionable (Marles et al. 1987).

Commercial Forms and Regulations In the United States, coumarin has been banned as a food additive since 1954. It has been placed in Class 3 of the Swiss Poison List. In Germany, drinking brandies (380/0 alcohol) are allowed to contain a maximum of 10 mg of coumarin per liter (Roth et al. 1994,402*). Literature See also the entries for scopoletin. Gray, Alexander 1., and Peter Waterman. 1978. Coumarins in the Rutaceae. Phytochemistry 17:845-64. (Contains a rich bibliography.) Marles, R. J., C. M. Compadre, and N. R. Farnsworth. 1987. Coumarin in vanilla extracts: Its detection and significance. Economic Botany 41 :41-47. Mendez, R. D. H., J. Murray, and S. A. Brown. 1982. The natural coumarins. Chichester, U.K.: John Wiley. Reisch, J., et al. 1968. Dber weitere C3-substituierte Cumarin-Derivate aus Ruta graveolens: Daphnoretin und Daphnoretin-methyHither. Planta Medica 15:372-76. ---. 1969. Dber die Cumarine der Wurzel von Ruta graveolens. Planta Medica 17:116-19. Shoeb, Aboo, Rhandhir S. Kapil, and Satya P. PopIi. 1973. Coumarins and alkaloids of Aegle marmelos. Phytochemistry 12:2071-72. Tatum, James H., and Robert E. Berry. 1979. Coumarins and psoralkens in grapefruit peel oil. Phytochemistry 18:500-502.