Caffeina. Caffeine (Theine), CH(CH)3ON.HO, U.S.P.

Thea sinensis, Linne'Coffea arabica, Linne'.  Trimethyl-xanthine, a feeble basic substance and alkaloid obtained from the leaves of the former, and seeds of the latter (Rubiaceae), also occurring in other plants; chiefly prepared synthetically.

Habitat.  S.E. Asia, China, India, Japan; cultivated.

Plant

Evergreen shrub 1.2-2 M. (4-6 degrees) high, much branched, bark brown, young twigs downy; leaves 5-10 Cm. (2-4') long, petiolate, acute at both ends, oval, irregularly serrate, veins prominent, dark green; flowers in winter, 2.5 Cm. (1') wide, yellowish-white; fruit 3-celled trigonous capsule, with thin brown woody pericarp; diluted alcohol or boiling water exhausts the leaves.  Dose, 3j-2 (4-8 Gm.).

Adulterations

Prussian blue, indigo, turmeric, gypsum; the three first impart color to water, the last soon deposits; various leaves, recognized by shape, venation, margin, etc.

Commercial

The plant, springing from seed, begins to yield satisfactory leaves in 3 years, and at 7 attains perfection, being about the height of a man.  Three collections are made yearly (Feb., Apr., June), the first, consisting mostly of young leaves, having greatest value.  There are two varieties: 1. Green, collected more carefully and quickly dried, and containing most tannin; 2. Black, owing to slower process, undergoing partial fermentation, which changes color and often impairs quality.

Constituents

Caffeine (Theine) 1-5 p.c., volatile oil .6-1 p.c., theophylline (isomeric with theobromine), ademine, tannin 11-21 p.c., boheic acid, albumin, resin, wax, ash 4-6 p.c. (14 p.c. being phosphoric acid); leaves yield 40 p.c. of aqueous extract.

Theophyllina. Theophylline, CH(CH)2.ON.HO, U.S.P. -- Syn., Theophyll., Dimethylxanthine; Synthetic -- Theocine; Ger. Theophyllinum, Theophyllin, Theocin.)  This organic base (alkaloid), isomeric with theobromine, is obtained sparingly from tea leaves, but mostly synthetically by a German patent under the name of theocine, wherein ammonia, carbon dioxide, potassium cyanide, acetic and formic acids are employed in a series of 12 reactions, and in fact becomes our first organic plant base (alkaloid) made on a commercial scale by strictly synthetic methods.  It is a white, crystalline odorless powder, bitter taste, permanent, soluble in solutions of potassium hydroxide and in ammonia water, in alcohol (80), water (120), more readily in hot water, sparingly in ether; saturated aqueous solution neutral; melts at 271 degrees C. (520 degrees F.).  Tests.: 1. Dissolve .2 Gm. in 5 cc. of potassium hydroxide T.S., or in 5 cc. of ammonia T.S. -- clear solution (dif. from caffeine, theobromine, paraxanthine).  2. Dissolve .2 Gm. in 5 c.c. of sulphuric acid--only faint yellow (abs. of readily carbonizable substances).  3. Dissolve .01 Gm. in hydrochloric acid 1 cc., add potassium chlorate .1 Gm., evaporate to dryness, invert dish over one containing a few drops of ammonia T.S. -- residue purple, destroyed by fixed alkalies.  4. Aqueous solution with tannic acid T.S.--precipitate, soluble in excess of reagent; when dried to constant weight -- loses 9.5 p.c. (water); incinerate .1 Gm. -- ash negligible.  Impurities: Caffeine, theobromine, paraxanthine, readily carbonizable substances.

Properties And Uses

Claimed to be the best diuretic, increasing amount of urine as well as solids; cardiac affections, nephritis, dropsy; similar to caffeine and theobromine, but much more effective; may produce gastric disturbances, renal irritation, which can be obviated by using its salt--theophylline sodio-acetate.  Dose, gr. 3-8 (.2-.5 Gm.), in warm tea.

Preparations

(Unoff.): Fluidextract, dose, mxv-60 (1-4 cc.).  Infusion (Tea), dose, ad libitum.

Properties And Uses

Similar to coffee, under Rubiaceae, page 580.

Allied Plants

1. Thea (Camel'lia, after George Joseph Camel or Camelli, a Dutch Jesuit missionary and botanist) japon'ica. -- Japan.  An ornamental shrub with poisonous seed.  T. oleo'sa (Camellia oleif'era) and T. drupif'era.  Seeds resemble those of T. sinensis and yield a bland fixed oil -- that of T. drupifera being fragrant.