A dried paste consisting chiefly of the crushed or pounded seeds of Paullin'ia cupan'a Kunth, yielding, by the official process, 4 per cent. of caffeine.
BOTANICAL CHARACTERISTICS.—A climbing shrub with alternate, imparipinnate leaves on long stalks, with five oblong-oval, irregularly sinuate-dentate leaflets 5 to 6 in. long and 2 to 3 in. broad, contracted into a shortly attenuated blunt point. Flowers in axillary spicate panicles. Fruit ovoid or pyriform, about the size of a grape, with a short, strong beak, and six longitudinal. ribs. Pericarp thin, leathery, hairy inside, inclosing lenticular, thorny seeds resembling small horse- chestnuts, and each invested with an easily removed, flesh-colored aril.
DESCRIPTION OF DRUG.—In cylinders, cakes, or balls of a dark reddish-brown color, not infrequently met with in the form of a light reddish-brown powder. In preparing the cylinders, etc., above referred to, the seeds deprived of arilode (papery shell) of the plant are first roasted, then ground, kneaded with water in a heated mortar into a pasty and pliable dough, made into forms, and dried. The forms thus made break with an uneven fracture, black-mottled from fragments of seeds. The drug has a peculiar characteristic chocolate-like odor and a bitter, astringent taste afterward sweetish. Guarana constitutes the habitual beverage of thousands of people in the Amazon valley.
Powder.—Characteristics: See Part iv, Chap. I, B.
CONSTITUENTS.—Tannic acid, not precipitated by tartar emetic or copper, gum, albumin, starch, a trace of volatile oil, saponin, a greenish fixed oil, and guaranine, an alkaloid identical with caffeine or theine. Of this it contains a much larger percentage as compared with other caffeine-yielding drugs. For example, good black tea gives an average yield of 2.13 per cent.; coffee, I per cent.; Paraguay tea (324), 1.2 per cent., and guarana, 4.5 per cent.
Preparation of Guaranine.—Treat the powder with boiling water. Evaporate the decoction on a water-bath to dryness, and exhaust the residue with chloroform. Distil off chloroform, treat residue with boiling water, filter, and evaporate the liquid to obtain caffeine (guaranine). Tea and kola can be treated in the same way for their active constituents.
ACTION AND USES.—Stimulant, especially beneficial in nervous headache, and used like tea, coffee, and other drugs containing caffeine-like principles. Dose: 15 to 60 gr. (1 to 4 Gm.).
Fluidextractum Guaranae. Dose: 15 to 60 drops (1 to 4 mils).