Kola. N. F. IV. Cola. Kola Nuts. Semen (Nuces) Colae. Noix de Cola, Noix de Gourou, Cafe du Soudan, Fr. Kolanuss, G.—It is described by the N. F. as "the dried cotyledons of several species of Cola Schott and Endlicher (Fam. Sterculiaceae), yielding not less than 1.5 per cent. of caffeine." N. F. The official drug is obtained chiefly from the large African tree Cola Acuminata R. Br., which is extensively cultivated in various portions of the tropical world for its seeds. The latter, under their Guinea name, or the Soudan name of guru nuts, are extensively employed as a caffeinic stimulant in Africa and other portions of the world. Six hundred tons of them are said to be sent yearly to Brazil for the use of the negroes, who, it is affirmed, also employ the seeds of Sterculia Chica A. St.-Hill. and S. striata A. St.-Hill. Three varieties of kola nuts are said to be the product of Cola acuminata. The most valuable, the kola of Sakhala, is the largest, and is of a white color. The kola of Kassi, of Siarra, and of Toute, is of medium size, red or white. The kola of Maninian is small and red. Of this white kola there are two varieties, one whitish, resembling the kola of Sakhala but smaller; the other more or less rose-colored and larger. The kola nut itself consists of the cotyledons which are "irregularly plano-convex, broadly oval, or approaching circular in outline, from 2.5 to 5 cm. in length, or triquetrous; heavy, hard and tough; brown with the outer surfaces slightly wrinkled, the inner surfaces lighter and smoother; edges slightly incurved and sharp. Odorless; taste slightly astringent. The powdered drug is reddish-brown and, when examined under the microscope, exhibits numerous starch grains, some of which show alteration, the normal grains up to 0.045 mm. in diameter, the smaller ellipsoidal or spherical, the larger ellipsoidal or irregularly oblong and occasionally with a protuberance on one side; many of the larger grains show lamellae and a circular point of origin of growth or a fissure through the center, and a distinct cross when examined with the polarizing microscope; parenchyma cells numerous, about 0.065 mm. in diameter, with reddish-brown walls."
Assay.—"Introduce 6 Gm. of Kola, 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 Kola. Evaporate the clear filtrate to dryness and dissolve the residue in 5 mils of 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 alkaloid with successive portions of chloroform until completely extracted, as shown by testing with iodine T.S. Evaporate the united chloroform solutions and dry the residue to constant weight at 80° C. (176° F.). The weight is the amount of caffeine from 5 Gm. of Kola. Kola yields not more than 3 per cent. of ash." N. F.
Daniell (P. J., 1865) was the first to show that kola nuts contained caffeine. Subsequently an elaborate analysis yielded to Attfield 2 1/3 per cent. of caffeine from the nut. Schuchardt summarizes the results of his chemical analyses as follows: 1. Martinique nuts contained 1.06 per cent. caffeine; 2, Ceylon, 1.39 per cent.; 3, Gaboon, 1.47 per cent.; 4, Tropical West African coast. Sierra Leone, 1.69 per cent.; 5, Tropical West Africa, interior, 1.61 per cent. The chemical studies of Parke, Davis & Co. show that as found in American commerce these nuts contain from 0.72 to 2.02 per cent. of caffeine. Heckel and Schlagdenhauffen (A. J. P., 1884) give theobromine 0.023 per cent., caffeine 2.35 per cent., tannin 1.62 per cent., as the result of their analyses. The researches of Knebel (A. J. P., 1892, 190), confirmed by Hilger (Ibid., 568), show that fresh kola nuts probably contain no caffeine, but a glucoside, kolanin,, which yields by its decomposition caffeine, glucose, and kola-red (C14H13(OH)5). Betaine is also stated to be present. The glucoside is decomposed by a ferment present in the nuts, and therefore readily yields the caffeine as a decomposition product. Schweitzer (1895) confirmed the results of Knebel and Hilger, and proposed for kolanin the formula C40H56N4O21. Knox and Prescott (Proc. A. Ph. A., 1896, 136), after an investigation, assert that the kola ferment does not assist in the liberation of caffeine, but attribute the presence of caffeine to the action of heat and moisture; they also give the name of kolatannin or kola-tannic add to the tannin of kola nuts, and propose a method of assay. (Proc. A. Ph. A., 1897, 131.) For Carlo's method of assay, see P. J., 1896, 289. Goris (P. J., 1906, lxxvi, p. 261) has separated from the kola nut a basic glucoside to which he gives the name of kolatine.
Travellers in Africa assert that the fresh kola nuts have a stimulant action which is not explicable on the ground of their caffeine content. But as they appear in European commerce their action is undistinguishable from that of the other caffeinic drugs. The experiments of Mosso (A. I. B., xix) seem to demonstrate conclusively the inertness of kola-red.
Kola is about equivalent to guarana, tea, coffee, etc., and may be substituted for them. In dose of one hundred and fifty grains (9.8 Gm.) a day, A. Hudson (T. G., ii) has found the nuts to act decisively in cardiac weakness.
The so-called male kola is essentially distinct from kola, being said to be the fruit of a small tree, Garcinia Kola (Fam. Guttiferae Heck.), and containing no caffeine. The fruit is oblong, about one and a half to three inches long and from three-quarters to one inch broad; it is trigonal in section, with a readily removable thin testa of a reddish-yellow to dark brown color, covered by markings which resemble those on the seed coat of the nutmeg. It is bitter and astringent. In the section the microscope reveals a number of resinous masses surrounded by cells rich in starch.
The seeds of Lucuma mammosa Griesbach (Fam. Sapotaceae), sometimes mixed with kola nuts, are recognized at once by their strong odor of prussic acid. Heckel and Schlagdenhauffen have observed the seeds of Heritiera litoralis Dryand (Fam. Sterculiaceae) mixed with kola nuts. These false kola nuts contain no caffeine, and are nearly orbicular and flattened in shape, one of the fleshy, purplish-brown cotyledons being only half the size of the other. (A. J. P., 1887, 446.)
The Dispensatory of the United States of America, 1918, was edited by Joseph P. Remington, Horatio C. Wood and others.