musk

a fragrant substance of plant or animal origin with valuable properties as a perfume and a perfume fixative.

Animal musk, secreted by the musk glands of some mammals, such as the musk deer, musk-ox and desman, is a grainy or greasy brown substance with an odor characteristic of the animal species from which it originates. Macrocyclic ketones constitute the aromatic principle of animal musk. Among others, these include muscone (about 1 percent in musk from the glands of musk deer), civetone (from the glands of a civet cat), and dihy-drocivetone (from the glands of a muskrat). Animal musk also consists of proteins, fats, cholesterol, and a variety of salts. Musk in animals functions as a chemical signal to stake out a territory against other individuals of the same species. In aquatic mammals, for example, the desman, muskrat, and beaver, musk also serves as a grease that prevents the fur from becoming soaked. Some macrocyclic lactones, such as tibetolide (present in the roots of garden angelica) and ambrettolide (in the oil of hibiscus seeds), constitute the aromatic principle of plant musk.

Many synthetic substances with different chemical structures have the odor of musk. They are used in industry instead of the costly and scarce natural musks. These include some macrocyclic lactones and oxalactones, nitromusks (musk-ketone, musk ambrette, musk-xylol), some substituted tetrahydronaphthalenes (for example, versalide), and some indan derivatives, such as phantolid.