Coronilla. Coronilla scorpioides Koch (Fam. Leguminosae).—In 1886 Cardot, in a thesis (Nancy) announced that the Coronilla scorpioides (Medic.) Koch, a papilionaceous plant of Southern France, is an active cardiac poison. In 1889 Schlagdenhauffen and Reeb (Rev. Gen. de Clin. et de Therap., July, 1889) isolated a glucoside, coronillin, to which they assigned the formula C7H12O5. It was a yellowish powder, soluble in water, acetone, and amyl alcohol; slightly soluble in chloroform and ether. Heated with diluted hydrochloric acid an amorphous resin was separated, coronillein. This also occurs as a yellow powder, but is not bitter to taste. It is insoluble in water, but dissolves in alcohol, acetone, and chloroform. The physiological studies by Gley, by Schlagdenhauffen and Reeb, and by Maramaldi (R. T; cxxxvi) have demonstrated that coronillin acts upon the heart in a manner similar to digitalis. In small doses it slows the pulse through stimulation of the inhibitory ganglia, and in larger quantity increases the tonicity and contractility of the heart, eventually leading to systolic spasm of the ventricle. This action upon the heart is accompanied by increase in the arterial pressure, followed after a time by lowering of the pressure, which apparently is the result of failure of diastole, causing the amount of blood forced out of the heart at each systole to be insufficient to fill the arteries. The drug also depresses the spinal cord, and lowers the respiratory movements by an action which is believed by Maramaldi to be partly centric and partly peripheral. Death is produced by cardiac arrest.
Locally, coronillin appears to be actively irritant. In Maramaldi's experiments it failed to assert its physiological action when administered to the dog by the mouth, a result believed by the investigator to be due to its decomposition by the acid in the stomach. As it has been found by various clinicians to be active in man when given by the mouth, it is probable that the comparative feebleness of human gastric juice permits of its absorption unchanged. The dose given by various clinicians has varied greatly, probably because of differences in purity of the various samples used; of the commercial coronillin the dose is commonly stated at present to be one and one-half grains (0.096 Gm.) from four to six times a day, but it must be noted that Schlagdenhauffen affirms that three-fourths of a grain (0.048 Gm.) is a toxic dose. Coronilla varia of Europe also probably contains coronillin. (V. Poulet, B. G. T., 1891.)