Ruta. Rue. Ruta graveolens.
Ruta.—Under this name the U. S. Pharmacopoeia formerly recognized Ruta graveolens L.; Rue; Rue odorante, Fr.; Garten-Raute, G.; Ruta, It.; Ruda, Sp., (Fam. Rutaceae). It is a low, shrubby plant, with several shrubby branching stems, which, near the base, are woody and covered with a rough, bark, but in their ultimate ramifications are smooth, green, and herbaceous. The leaves are fleshy, 2- to 3-pinnatified, the ultimate lobes or divisions being obovate-cuneate. The flowers are yellow, and disposed in a terminal branched cyme. The plant is a native of the south of Europe, locally established in pastures in the United States and cultivated in our gardens. The whole herb is active, and yields its properties to water and alcohol. The leaves have a strong, disagreeable odor, especially when rubbed. Their taste is bitter, hot, and acrid. When recent, and in full vigor, they have so much acrimony as to inflame and even blister the skin, if much handled; but the acrimony is diminished by drying. Their virtues depend chiefly on a volatile oil, which is contained in glandular vesicles, apparent over the whole surface of the plant. They contain, also, according to Borntrager, a peculiar acid which he calls rutinic acid, C25H32O15 (or C27H32O16, according to later writers). Rutinic acid is the coloring principle of rue, and has been found in various other plants; though, like quercitrin, yielding quercetin and sugar, it has been shown to be distinct. (J P. C., 1862, 165.)
Rue yields a very small proportion of a yellow or greenish volatile oil (Oleum Rutae, U. S., 1880), which becomes brown with age. According to Zeller, the yield from the fresh herb is 0.28 per cent., that from the seeds about 1 per cent. The oil has the strong unpleasant odor of the plant, and an acrid taste. Kane gives its sp. gr. at 0.837, its boiling point at 230° C. (446° F.). "A neutral reaction. Sp. gr. about 0.880. It is soluble in an equal weight of alcohol." U. S., 1880. It consists mainly of an oxidized constituent, which Strecker proved to be methyl-nonyl-ketone, CH3.CO.C9H19; that is, a ketone analogous to acetone, CH3.CO.CH3. This accounts for its yielding under treatment with oxidizing agents, pelargonic acid, C9H18O2. The methyl-nonyl-ketone, when pure, is a colorless liquid, fluorescing blue, boiling at 225° 0. (437° F.), and crystallizing at about 15° C. (59° F.). Schimmel & Co. (Schim. Rep., 1892, 31) state that pure oil of rue consists of 90 per cent. of methyl-nonyl-ketone, and solidifies even at a moderate temperature to a solid, crystalline mass, and has the sp. gr. 0.837.
According to von Soden and Henie, Algerian oil of rue differs from the ordinary oil in that it is chiefly composed of methyl-heptyl-ketone, with but small quantities of methyl-nonyl-ketone. Its specific gravity at 15° C. (59° F.) is 0.842; and it does not solidify at -15° C. (5° F.). (Ph. Ztg., 46.) Frederick B. Power and Frederic H. Lees (Trans. Chem. Soc., 1902) have since published an elaborate investigation of a similar Algerian oil. They find 80 per cent. of the two ketones, methyl-heptyl-ketone and methyl-nonyl-ketone, 10 per cent. of the corresponding carbinols (alcohols), pinene, 1-limonene, cineol, methyl salicylate, ethyl valerate, and some free fatty acids.
Rue is said to have been used by the ancients as a condiment. In modern times it has been employed in hysteria, worms, colic, and atonic amenorrhea and menorrhagia. Its medicinal activity depends upon its volatile oil, which is a powerful local irritant, causing, when applied to the skin persistently, burning, redness, and vesication, and when taken internally in large doses, violent gastric pains and vomiting, great prostration, confusion of mind, convulsive twitching, and in pregnant women, abortion. It has been considerably used in Europe for the production of criminal abortion, in a number of cases with fatal results. In a case of fatal poisoning in a man, reported by G. F. Cooper, there were vomiting, violent tormina and tenesmus, with bloody stools, great abdominal distention, with tenderness and severe strangury. (Med. Exam., N. S., ix, 720.) The dose of the oil is from two to five minims (0.12-0.3 mil ) every two or three hours. The rue itself is sometimes given in the dose of from ten to thirty grains (0.65-2.0 Gm.).