Oleum Rutae.—Oil of Rue.
Related entry: Ruta.—Rue
The essential oil distilled from Ruta graveolens, Linné.
Preparation and Description.—The fresh leaves and tops of Ruta graveolens, Linné, an herbaceous plant indigenous to the Mediterranean countries, yield, when distilled with water, about 0.06 per cent of volatile oil (Gildemeister and Hoffmann, loc. cit.). It is a colorless to yellow liquid, of a strong, penetrating, persistent odor. Its specific gravity is 0.833 to 0.840, this being nearly the lowest of all essential oils. It is slightly dextro-rotatory (+0° 30' to +2° 10'), and congeals between 8° and 10° C. (46.4° and 50° F.). The bulk of the oil distills between 215° and 232° C. (419° and 449.6° F.); 5 per cent distills below 200° C. (392° F.) (Umney, 1895 and 1897). The oil forms a clear solution with 2 to 3 volumes of 70 per cent alcohol.
Chemical Composition and Tests.—About 90 per cent of oil of rue consists of methyl-nonyl-ketone (CH3CO.C9H19, Giesecke, 1870; Gorup-Besanez and Grimm, 1871). Below 15° C. (59° F.) it is solid, boils at 224° C. (435.2° F.), and has a specific gravity of 0.8295 at 17.5° C. (63.5° F.). The oil is also said to contain lauric aldehyde (C12H24O) (C. G. Williams, 1858). No terpene is present in oil of rue. Adulterations with other essential oils increase the specific gravity and decrease the congealing point of oil of rue. Petroleum and oil of turpentine may be recognized by being insoluble in alcohol of 70 per cent by volume.
Action, Medical Uses, and Dosage.—Oil of rue is stimulant, antispasmodic, and emmenagogue. It has decidedly active properties. Locally it is irritant, and internally, even in small doses, it has produced severe gastro-intestinal and nervous disturbances. Oil of rue, in the dose of from 1 to 5 drops, 3 times a day, has been used with advantage in hysteria, convulsions, pertussis, amenorrhoea, and dysmenorrhoea. It is sometimes criminally used for the purpose of producing abortion, in which it is highly dangerous, having been followed by fatal consequences.