It is said to be poisonous, its action being similar to that of strychnine and brucine, and in activity standing midway between the two.
§ 405. Strychnic Acid.—Pelletier and Caventou obtained by boiling with spirit small, hard, warty crystals of an organic acid, from S. ignatius, as well as from nux vomica seeds. The seeds were first exhausted by ether, the alcohol solution was filtered and evaporated, and the extract treated with water and magnesia, filtered, and the residue first washed with cold water, then with hot spirit, and boiled lastly with a considerable quantity of water. The solution thus obtained was precipitated with acetate of lead, the lead thrown out by SH2, and the solution evaporated, the acid crystallising out. It is a substance as yet imperfectly studied, and probably identical with malic acid.
2. THE QUEBRACHO GROUP OF ALKALOIDS.
§ 406. The bark of the Quebracho Blanco[458] (Aspidosperma quebracho) contains, according to Hesse’s researches, no fewer than six alkaloids—Quebrachine, Aspidospermine, Aspidospermatine, Aspidosamine, and Hypoquebrachine. The more important of these are Aspidospermine and Quebrachine.
[458] See Liebig’s Annal., 211, 249-282; Ber. der deutsch. Chem. Gesellsch., 11, 2189; 12, 1560.
Aspidospermine (C22H30N2O2) forms colourless needles which melt at 206°. They dissolve in about 6000 parts of water at 14°—48 parts of 90 per cent. alcohol, and 106 parts of pure ether. The alkaloid gives a fine magenta colour with perchloric acid.
Quebrachine (C21H26N2O3) crystallises in colourless needles, melting-point (with partial decomposition) 215°. The crystals are soluble in chloroform, with difficulty soluble in cold alcohol, but easily in hot. The alkaloid, treated with sulphuric acid, and peroxide of lead, strikes a beautiful blue colour. It also gives with sulphuric acid and potassic chromate the strychnine colours. Quebrachine, dissolved in sulphuric acid containing iron, becomes violet-blue, passing into brown. The alkaloid, treated with strong sulphuric acid, becomes brown; on adding a crystal of potassic nitrate, a blue colour is developed; on now neutralising with caustic soda no red coloration is perceived. Dragendorff has recently studied the best method of extracting these alkaloids for toxicological purposes. He recommends extraction of the substances with sulphuric acid holding water, and shaking up with solvents. Aspidospermine is not extracted by petroleum ether or benzene from an acid watery extract, but readily by chloroform or by amyl alcohol. It is also separated from the same solution, alkalised by ammonia, by either amyl alcohol or chloroform; with difficulty by petroleum ether; some is dissolved by benzene. Quebrachine may be extracted from an acid solution by chloroform, but not by petroleum ether. Alkalised by ammonia, it dissolves freely in chloroform and in amyl alcohol. Traces are taken up by petroleum, somewhat more by benzene. Aspidospermine is gradually decomposed in the body, but Quebrachine is more resistant, and has been found in the stomach, intestines, blood, and urine. The toxicological action of the bark ranks it with the tetanic class of poisons. In this country it does not seem likely to attain any importance as a poison.