Castoreum

Castoreum kæsˈtɔriəm is a yellowish exudate from the castor sacs of mature beavers. Beavers use castoreum in combination with urine to scent mark their territory. Both beaver sexes have a pair of castor sacs and a pair of anal glands, located in two cavities under the skin between the pelvis and the base of the tail. The castor sacs are not true glands (endocrine or exocrine) on a cellular level, hence references to these structures as preputial glands, castor glands, or scent glands are misnomers. It is used as a tincture in some perfumes and, rarely, as a food additive. At least 24 compounds are known constituents of beaver castoreum. Several of these have pheromonal activity, of which the phenols 4-ethylphenol and catechol and the ketones acetophenone and 3-hydroxyacetophenone are strongest. Five additional compounds elicit a weaker response: 4-methylcatechol, 4-methoxyacetophenone, 5-methoxysalicylic acid, salicylaldehyde, and 3-hydroxybenzoic acid. There are also oxygen-containing monoterpenes such as 6-methyl-l-heptanol, 4,6-dimethyl-l-heptanol, isopinocamphone, pinocamphone, and two linalool oxides and their acetates. Other compounds are: benzoic acid, benzyl alcohol, borneol, o-cresol, 4-(4'-hydroxyphenyl)-2-butanone, hydroquinone, phenol. All those compounds are gathered from plant food. It also contains nupharamine alkaloids and castoramine, and cis-cyclohexane-1,2-diol. In perfumery, the term castoreum refers to the resinoid extract resulting from the dried and alcohol tinctured beaver castor. The dried beaver castor sacs are generally aged for two or more years to mellow. Castoreum is largely used for its note suggesting leather, typically compounded with other ingredients including top, middle, and base notes. Some classic perfumes incorporating castor are Emeraude, Chanel Antaeus, Cuir de Russie, Magie Noire, Lancôme Caractère, Hechter Madame, Givenchy III, Shalimar, and many "leather" themed compositions. In the United States, the Food and Drug Administration lists castoreum extract as a generally recognized as safe (GRAS) food additive.