Oleum Anisi. U. S., Br. Oil of Anise.
Ol. Anisi [Anise Oil]
"A volatile oil distilled from the ripe fruit of Pimpinella Anisum Linné (Fam. Umbelliferae) or from the ripe fruit of Illicium verum Hooker filius (Fam. Magnoliaceae). The botanical source from which it is derived must be stated on the label. If solid material has separated, carefully warm the Oil until liquefied, and thoroughly mix it before dispensing. Preserve it in well-stoppered, amber-colored bottles, protected from light." U. S. "Oil of Anise is the oil distilled from Anise Fruit; or from the fruit of the star-anise, Illicium verum, Hook. f." Br.
Huile volatile d'Anis vert (Badaine), Fr. Cod.; Essence d'Anis, Fr.; Oleum Anisi, P. G.; Anethol, Anisol, G.; Essenza di anise, It.; Esencia de anis, Sp.
The product of oil from anise is variously stated at from 1.56 to 3.12 per cent. The oil employed in this country is imported. It is colorless or yellowish, with the peculiar odor and taste of the seed. At 10° C. (50° F.) it crystallizes in flat tables, and it does not melt under 16.6° C. (62° F.). Its sp. gr. increases with age, and is variously given at from 0.9768 to 0.9903. It is soluble in all proportions in alcohol of 0.806; but alcohol of 0.840 dissolves at 25° C. (77° F.) only 42 per cent. Ether dissolves oil of anise in all proportions.
It consists of a small quantity of terpene, C10H16, but mainly of anethol, parapropenyl-anisol, C6H4C3H5OCH3 (about 85 per cent.), which is present, however, in two isomeric modifications, one solid at ordinary temperatures and heavier than water (solid anethol), the other liquid and more volatile (estragol or methyl chavicol). Anethol, both in the liquid and in the solid form, is present, and is the chief constituent of the oils of anise, star anise, and fennel.
Star anise oil contains besides anethol, pinene and phellandrene and some samples have been reported as containing safrol which is present to an appreciable extent in the so-called Japanese star anise oil which is from the leaves instead of the fruit. This latter oil contains eugenol as well as much less anethol than the oil from the fruit.
In consequence of its high price, it is frequently adulterated with spermaceti, wax, or camphor. The first two may be detected by their insolubility in cold alcohol, the last by its odor. In one instance as much as 35 per cent. of spermaceti was found. Schimmel & Co. have found fennel stearoptene in commercial oil of anise. (Ph. Rev., 1897, 94.) Procter met with a parcel, of which not less than five-sixths was alcohol. (A. J. P., xxvii, 513.) Its comparative mildness adapts it to infantile cases. Most of the oil of anise of commerce is the oil of star aniseed (Oleum Badiani, or Oleum Illicii). Oil of anise has also been distilled from the sweet cicely, Osmorrhiza longistylis, of the United States and Canada. (Ph. Rund., July, 1887.) For description and analysis of Russian oil of anise, see P. J., 1896, 164, also 243. Anisic acid is said to be antiseptic, resembling salicylic acid in its action.
Anethol which was official in the U. S. P. VIII is now recognized by the N. F. The description and tests are as follows: "The methyl ether of para-propenyl phenol [C6H4.C3H5.OCH5 = 148.1]. It is the main constituent in the oils of anise, star anise, and fennel, and is usually obtained from these by fractioning, chilling and crystallizing. Preserve it in well-stoppered, amber-colored bottles protected from light and air. Anethol is a colorless or faintly yellow, highly refractive liquid at a temperature of 23° C. (73.4° F.) or above, having a sweet taste and the aromatic odor of anise. At from 20° to 21° C. (68°-69.8° F.) it solidifies to a white, glistening, crystalline mass which remelts at from 22° to 23° C. (71.6°-73.4° F.). Anethol is almost insoluble in water, readily soluble in ether or chloroform, and forms a clear solution with two volumes of alcohol. Specific gravity: 0.984 to 0.986 at 25° C. (77° F.). Boiling point: 232° to 234° C. (449.6°-453.2° F.). Refractive index: 1.5 at 20° C. (68° F.). It is optically inactive or shows a deviation of not more than 0.08° in a 100 mm. tube at 25° C. (77° F.), due to slight traces of the oil from which the Anethol has been prepared (if prepared from oil of anise, this deviation will be laevorotatory, if from oil of fennel, dextrorotatory). Shake 10 mils of Anethol with 50 mils of a saturated aqueous solution of sodium bisulphite in a graduated cylinder and allow the mixture to stand for six hours. No appreciable diminution in the volume of Anethol will be observed nor does a crystalline deposit separate (aldehydes)." N. F.
Uses.—As a flavoring agent the oil of anise rivals any of the aromatic oils in the extent of its applicability. It is especially enjoyed by young children. Therapeutioally it is useful to stimulate peristalsis in colic and, according to Kobert, also as an expectorant. It has also been recommended as a means of destroying body vermin.
Dose, from three to five minims (0.2-0.3 mil).