Caffeina. Caffeine, CHONHO, U.S.P.

Coffea arabica, Linne'and Thea sinensis, Linne'.   A feebly basic substance (alkaloid) from the seeds of the former and leaves of the latter (Theaceae), also occurring in other plants; or prepared synthetically.

Habitat.  1.  Tropical Africa (Arabia, Abyssinia, Ceylon, Mocha); cultivated in tropical  countries (Java, W. Indies, S. America--Brazil (most), Guatemala (best), etc.).  2.  S. E.  Asia (upper Aseam, China, Japan, Java, S. United States; cultivated.

Syn.  Caff., Semen Coffea; Fr. Cafe'; Ger. Kaffee (bohnen), Caffeia; Caffein, Ger.  Coffeinum, Koffein, Kaffein, Thein.

Cof'fe-a.  L. For coffee, after Coffee, a province of Narea, in Africa, where it grows  abundantly; Arabic name of the decoction -- chaube', cave' cahua, caova.

A-rab'i-caL. Arabian -- i.e., its chief habitat.

Plant

Handsome shrub or small tree 3-4.5 M. (10-15 degrees) high, by cultivation trimmed down to 1.5-2 M. (5-6 degrees); bark smooth, gray; leaves 10-15 Cm. (4-6') long; 2.5-5 Cm. (1-2') wide, ovate, alternate, coriaceous, glossy, entire; flowers small, fragrant, white, funnel-shape, cymes; fruit oval, 12 Mm. (1/2') long, scarlet, but purple when ripe, 2-celled, 2-seeded drupe, each seed in a parchment-like endocarp; pericarp with scanty, scarcely succulent pulp, dehiscent; seed large, solitary in each cell, rounded back, flat on ventral surface (by which they face each other), hard, bony, grayish, deep narrow fissure in center.

Adulterations

Seed

Inferior grades: natural discolored (yellow and brown grain); artificial colored (Prussian blue, indigo, sugar, egg-albumen) -- removed by soaking in water; factitious coffee made of clay, kaolin, evaporated skimmed milk, etc. -- sink in ether, have little taste and no groove on flat side.  GROUND COFFEE: Sometimes roasted dandelion, chicory, amylaceous roots, corn, peas, beans, acorns, wheat, rye, sweet potatoes, coffee extract, etc.

Constituents

Caffeine (free and combined with caffeic acid) 1-2.3 p.c., caffearine, fat (olein, palmitin) 13 p.c., glucose, dextrin 15 p.c., proteins 13 p.c., caffeo-tannic acid, (chlorogenic, coffalic), volatile oil, citric acid, trigonelline, pectin, oxydase, moisture 12-15 p.c., ash 3-5 p.c., Mocha 7-8 p.c. -- K. Na, Mg, carbonates, phosphates.

Caffeina. Caffeine. -- While this is now prepared commercially -- chiefly synthetically, or from tea and tea-dust (sweepings), it may be obtained from a strong infusion of tea or unroasted coffee by adding lead acetate to precipitate tannin, coloring matter, etc., filtering, removing excess of lead by hydrogen sulphide, concentrating, crystallizing.  It is in white flexible, silky, glistening needles, usually matted together in fleecy masses, odorless, bitter, efflorescent, soluble in water (46), hot water (5.5), alcohol (66), chloroform (5.5), ether (530), benzene (100), boiling benzene (22), acetone (50); saturated aqueous solution neutral; melts, when anhydrous, at 236 degrees C. (457 degrees F.).  Tests: 1. Dissolve .01 Gm. In hydrochloric acid 1 cc.  add potassium chlorate .1 Gm., evaporate to dryness, invert the container over a vessel containing a few drops of ammonia T.S. -- residue purple, destroyed by fixed alkalies (murexide reaction).  2.  Aqueous solution + tannic acid T.S. -- precipitate, soluble in excess of reagent.  3.  Dry to constant weight -- loses 9 p.c.; incinerate -- ash .05 p.c.  4.  To .5 Gm. add sulphuric or nitric acid acid 5 cc. -- colorless, faintly yellow (abs. of readily carbonizable substances).  5.  Aqueous solution (1 in 50) + mercuric potassium iodide T.S. -- no precipitate (abs. of alkaloids).  Impurities: Alkaloids, readily carbonizable substances.  Dose, gr. 1-5 (.06-.3 Gm.).

Coffea arabica: A, blooming and fruiting twig; B, fruit; C, fruit, cross-section; D, fruit, longitudinal section; E, seed still partly enclosed in the parchment-like endocarp.

Commercial

Tree resembles our cherry, although more delicate, grows in clusters in hilly woods, 300-600 M. (1,000-2,000 degrees) elevation; first known in Europe, 1652, as coming from Arabia, Abyssinia, where it was popular in the 15th century. The Dutch first grew it in Europe, 1690, and introduced it into America at Surinam, 1718, Cayenne, W. Indies, 1725. There are four varieties: 1, Mocha, best, smallest, dark yellow, growing on the Arabian hills around Mocha; 2, Java (E. Indian, Ceylon), largest, pale yellow; 3, Rio, Brazilian (W. Indian, Demerara), intermediate size, bluish or greenish-gray; 4, Liberian C. Liberica -- most hardy and resistent to diseases), larger berries, finer flavor. The seeds are separated from papery endocarp by drying, passing between wooden rollers, and through a winnowing mill. In roasting at 250 degrees C. (482 degrees F.), the fat, sugar, and tannin are destroyed, some caffeine volatilized, and an emphyreumatic volatile oil (coffeol, coffeone), or some other active principle, volatile or otherwise, is developed -- losing 8 p.c. water, 9 p.c. organic matter, becoming pulverizable, more aromatic, and more soluble in water. Much care should be exercised in this process to use closed vessels and not too great heat. Caffeine exists in all plants as a complex tannoid, and as such possesses decided but different physiological activity from the free base (alkaloid). Decaffeinated coffee results from incipient germination, or dissolving out nine-tenths of the caffeine from raw beans, then roasting.

Preparations

1. Caffeina Citrata. Citrated Caffeine. (Syn., Caff. Cit.; Br. Caffeinae Citras, Caffeine Citrate; Fr. Citrate de Cafeine; Ger. Koffeincitrat.)

Manufacture: Dissolve citric acid 50 Gm. in hot distilled water 100 cc., add caffeine 50 Gm., evaporate to dryness on water-bath, constantly stirring toward the end, reduce to fine powder. It is a white powder, odorless, slightly bitter, acid taste and reaction; forms clear syrupy solution with small quantity of water, but caffeine precipitates on dilution, being redissolved by additional water; compound unstable; contains 48-52 p.c. of anhydrous caffeine, C8H10O2N4. 1. Mix 2 cc. of aqueous solution (1 in 10) with lime water (50) -- clear in the cold, but turbid upon boiling. 2. Dry to constant weight -- loses 5 p.c.; incinerate -- ash .1 p.c. 3. Aqueous solution (1 in 100) 5 cc. + mercuric sulphate T.S. 1 cc., heat to boiling, add potassium permanganate T.S. 1 cc. -- white precipitate. 4. Heat .25 Gm. + sulphuric acid 5 cc.in dish on water-bath for 15 minutes, protected from dust -- may be yellow, but not brown (abs. of tartrate). 5. Aqueous solution (1 in 100) 10 cc., acidulated with hydrochloric acid, + barium chloride T.S. -- no turbidity (abs. of sulphate). Impurities: Heavy metals, tartrate, sulphate, water. Should be kept in well-closed containers. Dose, gr. 2-10 (.13-.6 Gm.).

2. Caffeinae Sodio-Benzoas. Caffeine Sodio-Benzoate. (Syn., Caff. Sod.-Benz.; Fr. Soude benzoate de Cafeine; Ger. Caffeinum-Natrium benzoicum, Koffein-Natriumbenzoat.)

Manufacture

Mix caffeine and sodium benzoate each 50 Gm., rub to smooth paste with alcohol q.s., dry in moderately warm place. It is a white powder, odorless, bitter, soluble in water (1.1), some caffeine separating on standing, alcohol (30), partly in chloroform; aqueous solution (1 in 20) neutral, slightly acid or alkaline, not reddened by phenolphthalein T.S.; contains 47-50 p.c. of anhydrous caffeine and 50-53 p.c. of sodium benzoate, NaCOH.  Tests:  1.  Heat -- decomposes with evolution of white vapors of caffeine -- carbonaceous residue effervesces with acids and colors flame yellow.  2.  Aqueous solution + ferric chloride T.S. -- salmon-colored precipitate; + diluted hydrochloric acid -- white precipitate (benzoic acid).  3.  Dry to constant weight -- loses 5 p.c.  Impurities: Heavy metals, water, chlorinated compounds, readily carbonizable substances.  Dose, gr. 2-10 (.13-.6 Gm.), in powder, capsule, effervescent draught, hypodermically (?).

Prep.: 1.  Ampullae Caffeinae Sodio-Benzoatis, N.F.,8.5 gr. (.55 Gm.).  Dose, 2-4 ampuls.

3.  Caffeinae Sodio-Salicylas, N.F., -- caffeine, sodium salicylate, aa, 50 p.c., alcohol q.s.  Dose, gr. 1-5 (.06-.3 Gm.)

4.  Pulvis Acetanilidi Compositus, N.F., 10 p.c.

5.  Sal Pot. Brom. Eff. Co., N.F., 4/5 p.c.

Unoff. Prep.: Effervescent Citrated Caffeine, 1.9 p.c. of anhydrous caffeine, 3j-2 (4-8 Gm.).

Properties

Tonic, stimulant, nervine, antiemetic, laxative, diuretic, antiperiodic, antiseptic.  Caffeine in small doses stimulates appetite, digestion, secretion of bile, quickens heart action, respiration, increases arterial tension, urine; normal doses, cerebral stimulant, causing nervous restlessness, wakefulness, increased mental activity; large doses (gr. 5-10 (.3-.6 Gm.) produce heaviness of head, insomnia, delirium, rapid, feeble pulse, cold extremities, elevated temperature, convulsions, paralyzes cardiac muscle, but death occurs from paralysis of respiration; valuable as a hydragogue diuretic; ordinary salts not suitable for hypodermic use as they decompose by the presence of water.  Caffeine sodio-benzoate as a diuretic, cerebral and cardiac stimulant has the advantage of being moderately stable and non-irritating.

Uses

Caffeine in neuralgia or nervous headaches, diarrhea of cholera, phthisis, cardiac and renal dropsies, lithemia, gout, insomnia of chronic alcoholism, adynamic fevers.  Coffee in intermittents, asthma paroxysms, opium narcosis, to antagonize general torpor of nervous centers; it is used mostly as a beverage, for which alone about 1,500,000,000 pounds (680,272 Kg.) are consumed annually, making 1 pound (.46 Kg.) to every living person; in the United States about 6-7 pounds (2.7-3 Kg.) per capita; in Holland 10 pounds (4.6 Kg.); an average cup contains 2.61 gr. (.2 Gm.) of caffeine.

Derivative Products

1. Coffea arabica or C. Liber'ica; Coffea Tosta, Coffee, Roasted Coffee, N.F. -- The dried ripe seed, deprived of most of the seed-coat, and roasted until a dark brown color and characteristic aroma are developed yielding not less than 1 p.c. of caffeine, 3-5 p.c. of ash, and 10 p.c. of fat.  Seed oval, variable size, one side convex, other flat with longitudinal groove showing papery seed-coat traces in cleft; characteristic aroma, pleasantly bitter taste.  Powder, deep brown -- many seed-coat fragments of parenchyma and stone cells, many endosperm cells with porous walls, oil and aleurone grains; starch grains few or wanting, no tracheae.  Dose, 3ss-1 (2-4 Gm.); 1.  Fluidextractum Coffeae (1st menstruum: glycerin 6.5 cc., alcohol 25, water 68.5; 2d: 25 p.c. alcohol q.s. 100, dose 3ss-1 (2/4 cc).  Decoction, Infusion.