Guarana. U. S.
"A dried paste consisting chiefly of the crushed seeds of Paullinia Cupana Kunth (Fam. Sapindaceae), yielding not less than 4 per cent. of caffeine." U. S.
Paullinia, Brazilian Cocoa, Guarana Bread; Guarana, Fr. Cod.; Pasta Guaranae; Guarana, G., lt.; Paulinia, Guarana, Sp.
There are described of the genus Paullinia 121 species, all of them confined in their geographical range to tropical and subtropical South America, except one, which has strayed to Eastern and Western Africa, and two others which are found in Mexico and in the gardens of the Sandwich Islands. The name of the genus was given in honor of Christ. Fred. Paullini, a German medico-botanical writer, who died in 1712.
The Paullinia Cupana Kunth is a climbing shrub with alternate compound imparipinnate leaves, which is native to the Northwestern provinces of Brazil. The flowers are of yellowish color, growing in spicate panicles. The leaves are long petioled, the leaflets being 5 to 6 inches long by 2 or 3 inches wide, and sinuate dentate on the margins. The fruit is ovoid or pyriform and about the size of a grape, and contains 1 to 3 seeds which resemble small horse chestnuts.
It is probable that in the preparation of guarana the seeds of the allied species P. sorbilis Martins, are used interchangeably with those of the official species.
The seeds, which look like small horse-chestnuts, are lenticular and almost thorny, and invested with a flesh-colored arillus, which is easily separable when dry. Guarana is made exclusively by the Guaranis, a tribe of South America Indians, and probably varies in the details of its preparation, as it certainly does in appearance and quality. The drug appears to be produced almost exclusively from plants cultivated in the region of the lower Madeira and southward. After the seeds are shelled and thoroughly washed they are roasted for about six hours, and their external papery shells are then removed by placing them in sacks and beating them with clubs; or, after the seeds have been broken in a mortar, the coarse powder is mixed with a little water, and then kneaded into a paste, which is shaped into cylindrical or globular masses. The latter are dried, sometimes in the sun, or more usually by the heat of a slow fire so arranged as to avoid smoke. When finished, the masses are of a reddish-brown color, rugose on the surface, very hard, with an irregular fracture, and of a marbled appearance when broken, due to the fragments of the seeds and their black testa embedded in the mass.
Guarana occurs in a number of molded forms, and an excellent collection of these can be found in the Philadelphia Commercial Museum. Stockman (P. J., liii; P. J., lxxxix, p. 685) describes and illustrates some of these interesting forms.
Properties.—It is officially described as follows: "Usually in cylindrical sticks, about 3 to 5 cm. in diameter, externally dark reddish-brown; hard and heavy; fracture uneven, often fissured in the center; internally pale reddish-brown, showing more or less coarse fragments of seeds and occasionally their blackish-brown integuments; odor slight; taste slightly astringent and bitter. The powder is light pinkish-brown; consisting mostly of irregular masses of parenchyma containing more or less .altered starch grains; unaltered starch grains occasional, varying from spherical and polygonal to ellipsoidal and broadly ovoid, 0.01 to 0.025 mm. in diameter; occasional fragments with narrow, elongated sclerenchymatous cells; the walls being thick, yellowish and non-lignified. Place on a slide a drop of hydrochloric acid, add about 0.001 Gm. of powdered Guarana, then add a drop of gold chloride T.S. and allow the mixture to stand for a few minutes; beginning at the edge of the mount, crystals of caffeine and gold chloride separate in the form of orthorhombic plates and needles, the latter usually occurring in spheroidal aggregates and finally forming branching groups.
"Assay.—Introduce 6 Gm. of Guarana, in No. 60 powder, into a flask and add 120 mils of chloroform and 6 mils of ammonia water. Stopper the flask, shake it frequently for half an hour, then let it stand four hours. Again shake the flask vigorously and when the drug has settled, filter the liquid rapidly through a pledget of purified cotton and collect 100 mils of the filtrate, representing 5 Gm. of Guarana. Evaporate the clear filtrate to dryness and dissolve the residue in weak sulphuric acid with the aid of a gentle heat. When the liquid has cooled, filter it into a separator and wash the container and filter with several small portions of distilled water. Now add ammonia water until the liquid is distinctly alkaline to litmus and shake out the caffeine with chloroform until completely extracted, as shown by testing with iodine T.S. in place of the usual mercuric potassium iodide T.S. Evaporate the united chloroform solutions and dry the residue to constant weight at 80° C. (17610 P.). The weight is the amount of caffeine from 5 Gm. of Guarana (see Proximate Assays, Part III)." U. S.
Guarana is of a somewhat astringent and bitterish taste, and in this, as well as in its odor, bears some resemblance to chocolate, though not oleaginous. It swells up and softens in water, which partially dissolves it. It is also partly soluble in alcohol. Martius found in it a crystallizable principle, which he named guaranine, but which was later proved by Berthemot and Dechastelus to be identical with caffeine. Alexander Bennett, in an elaborate series of physiological experiments, 'confirmed this identity Caffeine may be obtained by microsublimation and Rosenthaler (B. P. G., xxi, p. 532) describes the crystals obtained from guarana by means of pyroanalysis. According to Berthemot and Dechastelus, the caffeine exists in the seeds united with tannic acid, with which it appears to form two compounds, one crystallizable and soluble in water, the other of a resinoid appearance and insoluble. Besides these ingredients the seeds contain free tannic acid, gum, albumen, starch, and a greenish fixed oil. (J. P. C., xxvi, 514.)
M. I. Wilbert (J. A. Ph. A., 1914, 1286) reported a compilation of analyses of guarana comprising 41 samples in which the caffeine content varied from 3.72 to 5.16 per cent.
Rochefontaine and Gusset prepared caffeine by mixing one part of calcined magnesia with five parts of powdered guarana, moistening with water, and, after standing twenty-four hours, exhausting the mass with boiling chloroform, evaporating the chloroform, treating the residue with boiling water, filtering, and evaporating over sulphuric acid. (A. J, P., 1886, p. 248.) F. V. Greene (United States Navy) prefers a process for obtaining caffeine from guarana similar to one proposed by Wayne for its extraction from tea and coffee. See U. S. D., 19th ed., p. 606.
F. V. Greene has shown that the tannic acid from guarana has different properties from that
found in other plants, and proposes to call it paullinitannic acid. (A. J. P., 1877, 390.) Foumier has found in guarana, besides caffeine tannate, the following principles: gum, starch, an acrid green fixed oil, a concrete volatile oil, an aromatic liquid volatile oil soluble in water with a little alcohol, another liquid volatile oil scarcely soluble in water, a peculiar principle not precisely determined, and tannic acid. (J. P. C., April, 1861,291.) E. R. Squibb examined commercial guarana, and obtained 4.38 per cent. of alkaloid from good specimens. On account of the uncertainty of the composition of guarana, he recommended physicians to prescribe fluidextract of green coffee in its place. (See Ephem., 1884, 612.)
Uses.—The effects of guarana upon the system are chiefly those of its alkaloid, although it contains enough tannin to have an appreciable influence. It is habitually employed by the Indian's, either mixed with articles of diet, as with cassava or chocolate, or in the form of drink, prepared by scraping it, and suspending the powder in sweetened water, precisely as other nations use teas, coffees, etc. It is also considered by the Indians useful in the prevention, and cure of bowel complaints. Gavrelle, who was at one time physician to Dom Pedro, in Brazil, and there became acquainted. with the virtues of this medicine, called the attention of the profession to it some years since in France. It is now used in medicine almost exclusively to give relief during the paroxysm of migraine, and in atonic chronic diarrhea, taken three or four times a day.
Dose, of the powder, twenty to sixty grains (1.3-3.9 Gm.); of the fluidextract, twenty to sixty minims (1.3-3.75 mils).
Off. Prep.—Fluidextractum Guaranae, U. S.; Elixir Guaranae (from Fluidextract), N. F.
The Dispensatory of the United States of America, 1918, was edited by Joseph P. Remington, Horatio C. Wood and others.