Coptis. N. F. IV. Goldthread. Coptide, Fr. Gelbe (Kleinste) Niesswurz, G.—"The dried plant of the Coptis trifolia (Linne) Salisbury (Fam. Ranunculaceae)." N. F. This plant inhabits the northern region of this continent and of Asia, and is found in Greenland and Iceland. It delights in the dark shady swamps and cold morasses of northern latitudes and alpine regions, and abounds in Canada and in the hilly districts of the Northern United States.
Dried goldthread, as brought into the market, is "in loose, matted masses consisting of long, much branched rhizomes and their small roots together with the leaves. Rhizomes orange or golden-yellow; leaves evergreen, long and slenderly petioled, trifoliate, the segments broadly obovate-cuneate, crenately lobed and toothed with sharp-pointed teeth, prominently veined, smooth, coriaceous, dark green and shining but often drying to a dull brownish hue; flowers, if present, small, solitary, terminating slender scapes, sepals five to seven, oblong, obtuse, deciduous; petals five to six, pale yellow, small club shaped; stamens numerous. Odor faint; taste purely bitter without astringency. The powdered drug is yellowish-green and, when examined under the microscope, exhibits numerous, mostly simple, starch grains, somewhat rounded, up to 0.007 mm. in diameter; fragments of leaf epidermis, composed of cells with wavy vertical walls and broadly elliptical stomata, the latter up to 0.024 mm. in length; fragments of the nerved scales from the nodes, composed of cells with yellow walls; leaf parenchyma cells containing chloroplastids; few, simple, thick-walled hairs from the midrib of the leaf, from 0.035 to 0.075 mm. in length; elongated, epidermal cells from the roots having yellow walls and filled with reddish contents; fragments of epidermal and sub-epidermal cells from the rhizome, similar to those from the root, but without reddish contents, often filled with a yellowish content; groups of elongated parenchyma cells about 0.06 mm. in length and about 6.01 mm. in width, many being filled with starch grains; tracheae with bordered pores or spiral markings, about 0.02 mm. in width; narrow thin-walled, porous sclerenchyma fibers. Coptis yields not more than 8 per cent. of ash." N. F. It imparts a bitterness and yellow color to water and alcohol, but most perfectly to the latter, with which it forms a bright yellow tincture. The infusion is precipitated by silver nitrate and lead acetate. (Bigelow.) It affords no evidence of containing either resin, gum, or tannin. The plant undoubtedly contains berberine, which, according to F. F. Mayer (A. J. P., 1863) and E. Z. Gross (A. J. P., 1873), is associated with another alkaloid. Gross states that coptine differs from berberine in its colorless crystals, and by forming with mercuric potassium iodide (Mayer's reagent) a crystalline instead of flocculent precipitate. (See also John J. Schulz, A. J P., 1884, 261.)
Goldthread is a simple tonic bitter. In New England it is employed as a local application in aphthous ulcerations of the mouth, but it probably has no other virtues in flits complaint than such as are common to the simple bitters. It may be given in substance, infusion, or tincture. The dose of the powder is from ten to thirty grains (0.65-2.0 Gm.); of a tincture made with an ounce of the root to a pint of diluted alcohol, one fluidrachm (3.75 mils), and of the N. F. fluidextract thirty minims (2 mils).
The Coptis Teeta of Wallich, which grows in the mountainous regions bordering on Assam, is much used as a tonic by the natives and by the Chinese. It is analogous in properties to C. trifolia Salisb., and is said to contain 8 ½ per cent. of berberine. It has been brought into use in British India. It is highly commended by Twining as a stomachic tonic. (P. J., 1870, 161.) Coptis anemonifolia Sieb. and Zucc. also contains berberine, and has been used in Japan in intestinal catarrh. (Sei-i-Kwai, 1892.)