441. Gentiana.—Gentian

The dry rhizome and roots of Gentia'na lu'tea Linné.

BOTANICAL CHARACTERISTICS.—Root perennial, large; stem 2 to 3 feet high, Leaves opposite, sessile, 5- to 7-nerved, ovate-acute, more or less clasping. Flowers in whorls, bright yellow; corolla with 5 or 6 green glands at its base; stigmas 2.

HABITAT.—Mountainous portions of Central Europe.

DESCRIPTION OF DRUG.—Cylindrical, fleshy, and very long, often 3 feet or more; it is generally cut longitudinally about 100 to 200 mm. (4 (1/5 to 1 3/5 in.) thick; in drying, these to 8 in.) long, and 5 to 40 mm. slices are depressed in the center and the bark overlaps; yellowish-brown, much wrinkled longitudinally and marked transversely, especially in the upper portion, with numerous rings. Transversely the bark is rather thick, wrinkled, and contorted, separated by a black cambium line from the yellowish-brown, porous, and spongy meditullium marked with indistinct medullary rays. Fracture irregular, brittle when dry, flexible and tough when damp; odor pronounced and characteristic; taste intensely bitter, sweetish, and not disagreeable.

Gentiana catesboei, the blue gentian of the Southern. States, growing in mossy swamps, is said to be little inferior to the official species. It is sometimes used to adulterate senega. Other indigenous species, as G. purpurea and G. punctata, have about the same properties as the official gentian and are used similarly. The herb G. quinqueflora is used in liver affections, chronic ague, jaundice, etc.

Powder.—Characteristic elements: See Part iv, Chap. I, B.

CONSTITUENTS.—The bitter principle is a neutral principle, gentiopicrin, C₂₀H₃₀O₁₂, the yellow color is due to gentisin, C₁₄H₁₀O₅, or gentisic acid (tasteless yellow prisms). The root also contains from 12 to 15 per cent. of glucose (gentianose), C₁₆H₆₆O₃₁, but is remarkable in that it contains no starch, calcium oxalate, or tannin. Ash, not to exceed 6 per cent.

Preparation of Gentisic Acid.—The alcoholic extract is washed with water, then with ether. The residue dissolved in alcohol yields the acid on evaporation. It is in yellow, tasteless crystals, partially soluble in alcohol and ether; with ferric salts gives dark brown color.

Preparation of Gentiopicrin.—Obtained by making aqueous solution of alcoholic extract. This solution is subjected to the absorptive action of charcoal. Charcoal is then boiled with alcohol, tincture evaporated, and treated with lead oxide to remove color. Lead removed by H₂S; solution agitated with ether. Set solution aside to crystallize. Yellowish-brown, soluble in water and dilute alcohol.

ACTION AND USES.—Simple bitter tonic, long known and very valuable. Dose: 5 to 30 gr. (0.3 to 2 Gm.).

OFFICIAL PREPARATIONS.

Fluidextractum Gentianae, Dose: 5 to 30 drops (0.3 to 2 mils) .

Extractum Gentianae 5 to 10 gr. (0.3 to 0.6 Gm.).

Tinctura Gentianae Composita (10 per cent., with orange-peel and cardamom), 1 to 2 fl. dr. (4 to 8 mils).

A Manual of Organic Materia Medica and Pharmacognosy, 1917, was written by Lucius E. Sayre, B.S. Ph. M.