Angustura.—Angustura Bark.

The bark of Galipea Cusparia, St. Hiliare (Galipea officinalis, Hancock; Cusparia febrifuga, Humboldt; Galipea febrifuga, Baillon; Bonplandii trifoliata, Willdenow.
Nat. Ord.—Rutaceae.
SYNONYM AND COMMON NAMES: Cuspariae cortex, Cusparia bark, Angostura bark.
ILLUSTRATION: Bentley and Trimen, Med. Plants, 43.

Botanical Source.—This tree seldom exceeds 20 feet in height, with a stem whose diameter is from 2 to 6 inches, having irregular branches, and a smooth bark. The leaves are alternate, trifoliate, and petiolate; the leaflets oval, acute at the base, acuminate at the apex, smooth, glossy, bright-green, having a tobacco-like smell when fresh and bruised, from 6 to 10 inches long, 2 to 4 broad, some of them marked with small, whitish, round spots. The petiole is about the length of the leaflets, and slightly channeled. The flowers are white and beautiful, with a narcotic odor, and are borne in cylindrical, contracted, stalked panicles, longer than the leaves, the branches being about three-flowered. Calyx inferior, campanulate, five-toothed, hairy; corolla somewhat curved before expansion, nearly an inch long, downy on both sides; of the five petals, two larger than the others. Sterile stamens, five, subulate, tipped with a pellucid, watery gland, fertile stamens, two; style, erect; stigma, simple. The fruit or carpels are five, or fewer by abortion, becoming villous as they mature, two-seeded, with a strong, elastic, separable, two-valved endocarp (L.).

History.—There has been heretofore some uncertainty relative to the tree from which the official angustura bark is obtained, but the question has been definitely settled by Dr. Hancock, who has ascertained that it is chiefly the product of a tree to which be has given the above name. Galipea officinalis, now Galipea Cusparia, is official in the British Pharmacopoeia. Under Hancock's name, it was formerly official in the U. S. P. It is found growing in great abundance in the missions of Carony, Tumeremo, etc., and other parts of Columbian Guiana.

Description.—The bark, as imported from the West Indian ports, is in flat pieces or incomplete quills, from 2 to 4 or even 8 inches long, 1 or 2 inches in breadth, and 1 or 2 lines in thickness. Its outer surface is dirty-grayish-yellow in color, often speckled in the smaller pieces with lighter gray spots and elevations; the inner surface is dull-brown; and the substance of the bark is yellowish-brown. It breaks easily, the transverse fracture being smooth and somewhat resinous in appearance; and presents white, shining striae, produced by aggregations of crystalline, calcium oxalate; its powder has a grayish-yellow color, somewhat like that of rhubarb. When soaked in water, it is soon softened sufficiently to be easily divided by means of shears. It has a characteristic, unpleasant odor, and an intensely bitter, somewhat aromatic and acrid taste. Water, alcohol, or proof-spirits take up its virtues.

Chemical Composition.—Fischer found in it a volatile oil 0.3, peculiar bitter principle 3.7, bitter hard resin 1.7, balsamic soft resin 1.9, elastic resin 0.2, gum 5.7, lignin 89.1. By submitting the bark to distillation with water, a yellowish-white, odorous, acrid, volatile oil is obtained, which is not so heavy as water. The bark also contains nearly 1.5 per cent of a peculiar neutral, crystalline principle, named cusparin by Saladin, and termed the peculiar bitter principle by Fischer. Cusparin, or angosturin (Pereira), is obtained by submitting the alcoholic tincture of the bark (prepared without heat) to slow atmospheric evaporation; the crystals thus obtained are to be purified by repeated crystallization from alcohol and agitation with ether and hydrated oxide of lead. It forms tetrahedral crystals, is fusible at 44.4° C. (112° F.), and loses 23.09 per cent of its weight; cold water dissolves ½ per cent and boiling water 1 percent of it; it is freely soluble in alcohol, but not in ether or volatile oils; readily dissolves in the concentrated acids, and more sparingly in the alkalies, and its acid solution yields a whitish precipitate with the tincture of galls (Saladin, Jour. de Chim. Med., IX, 388).

Cusparin, obtained in the cold, occurs in needle-like crystals. It is inflammable. The volatile oil, which has a boiling point at 266° C. (511° F.) is represented, according to Herzog, by the formula, C13H24O. Oberlin and Schlagdenhauffen, who examined the bark in 1878, found volatile oil, resin, fat, dissolved by alcohol; wax, fat, and stearic acid dissolved by benzin; moisture; and a bitter, yellow body, which yielded a crystalline alkaloid called by them angusturine (C10H40NO14). is fusible at 85° C. (185° F.), turns green when treated with sulphuric acid mixed with oxidizers-as nitric acid-but with pure sulphuric acid a red coloration ensues. In 1892 Beckurts and Nehring made a detailed investigation of the bark, isolating therefrom the following four alkaloids: Cusparine (C20H19NO3) fusing point 98° C. (208.4° F.); readily soluble in alcohol and ether, its salts being difficultly soluble; cusparidine (C19H17NO3) fusing point 78° C. (172.4° F.); galipine (C20H21NO3) fusing point 115.5° C. (240° F.), and galipidine (C19H19NO3) fusing point 111° C. (231.8° F.), the proper crystallizing solvent for the latter three alkaloids being light petroleum. The authors found, besides an essential oil extracted by means of ether. angusturine, a bitter principle insoluble in ether, having a fusing point of 58° C. (136.4° F.), and a glucoside not further examined. The bark was previously studied also by Koerner and Boehringer, in 1884, who found three alkaloids, one being identical in composition and fusing point with the galipine of Beckurts and Nehring.

Substituted Barks.—Some years since a poisonous bark was introduced as the true bark, and the administration of which was attended with fatal results. This spurious bark was at first supposed to be the product of the Brucea ferruginea, but is now recognized as the bark of Strychnos Nux vomica. It is known as the FALSE ANGUSTURA BARK, and may be detected by the following marks: The genuine bark has a strong and disagreeable odor; a bitter, durable, pungent taste; softens in water, and imbibes it quickly; is very light; tissue not compact; has a resinous, shining fracture, and when touched with nitric acid becomes colored a dull red; the false bark has no odor; an insupportably bitter, very durable taste; does not soften sensibly in water; is very heavy and compact; as a dull and blackish fracture, and nitric acid turns its fractured surface bright red and its rusty epidermis an intense green. The false bark is rarely met with in this country (Duncan). It contains brucine.

A bark known as Brazilian angustura, derived from Esenbeckia febrifuga, Martius, (Evodia febrifuga, St. Hilaire), and collected in Brazil, has been met with in substitution for angustura (Maisch, Amer. Jour. Pharm., 1874, p. 414). It occurs in pieces a little curved, and having a thickness of about 1/16 inch. It is very bitter, but not aromatic to the taste, nor does it swell when macerated in water. The inner layers are deep-brown, over which are blotches of a soft, corky layer of a brown-gray hue, having internally a faint, orange-rusty brown color. Its fracture is short and fibrous, and there is an absence of the white, shining strive, due to the raphides of calcium oxalate found in the true bark. Oberlin and Schlagdenhauffen found in the Brazilian product an alkaloid turning yellow-green upon treatment with sulphuric acid. To this principle they gave the name evodine (esenbeckine), and the formula, C6H18NO6.

Oberlin and Schlagdenhauffen record the following additional substitutions of angustura bark: Guaiacum bark, Copalchic bark, and the barks of Cinchona bicolorata and Samadera Indica (Amer. Jour. Pharm., 1879, p. 83).

Action, Medical Uses, and Dosage.—In large doses, of from 20 to 60 grains, it is emetic and cathartic; in doses of from 5 to 15 grains, non-astringent tonic and febrifuge. Recommended in bilious diarrhoeas and dysenteries, intermitterits, dropsies, etc. It is seldom used, on account of its liability to adulteration with the poisonous bark of the Strychnos Nux vomica, known as the False angustura bark. Dose of the bark, 10 to 30 grains; of the infusion (℥ss in Oj), 1 to 2 fluid ounces.

King's American Dispensatory, 1898, was written by Harvey Wickes Felter, M.D., and John Uri Lloyd, Phr. M., Ph. D.