Adonis. N. F. IV. Vernal Pheasant's Eye. Sommerteufelsauge, G.—It is official in the N. F. IV, in which it is defined as "the dried, overground portion of Adonis vernalis Linne (Fam. Ranunculaceae), without the presence of more than 5 per cent. of foreign matter." This ranunculaceous plant of Northern Europe and Asia has long been used as an abortifacient, while its rhizome sometimes occurs in commercial black hellebore as an adulteration. Linderos examined the leaves and found in them 10 per cent. of aconitic acid. (Ann. Ch. Ph., 1876, 340.) Cervello, in 1882, obtained from the plant a glucoside, to which he gave the name of adonidin. For improved method of preparation, see P. J., vol. xvi, 145, and A. J. P., 1887, 609. This glucoside occurs in the form of a somewhat hygroscopic, canary-yellow powder of an intensely bitter taste; soluble in water, alcohol, and in amyl alcohol; insoluble in anhydrous ether, chloroform, oil of turpentine, or petroleum benzin. Its reaction is neutral. It reduces Fehling's solution, if previously heated with a few drops of hydrochloric acid. It exists in small quantities in all portions of the plant. For further details as to reactions, see P. J., xv, 145. Podwyssotzki found commercial samples of adonidin to be mixtures of the active principle with other constituents of the plant. He gives the name of picroadonidin to the active principle, which he describes as an amorphous glucoside having an excessively bitter taste, possessing the properties of a cardiac poison in the highest degree, and being easily soluble in water and alcohol and entirely soluble in ether. (P. J., xix, 1888, 346.) According to Fuckelman, confirmed by Mercier (Nouv. Rem,., 1914), commercial adonidin is a mixture of a neutral body with a hemolytic acid, adonic acid. Cervello states (A. E. P. P., xv) that adonidin exists also in the Adonis cupaniana of Southern Europe, and F. Borgiotti affirms the value of A. aestivalis, L., in heart affections. (D. M. Ztg., Aug., 1888.) Tahara asserts that the glucoside of Adonis autumnalis, L., is distinct, and calls it adonin (C24H40O9) (Ber. d. Chem. Ges., xxiv), while Y. Inoko (A. E. P. P., xxviii) affirms that the glucoside of A. amurensis of Japan is also peculiar, and assigns to it the formula C20H40O9, allied to adonidin, but much less powerful.

Merck has described an additional crystalline principle, which fuses at 102° C. (216° F.), is very soluble in water and warm alcohol, and crystallizes in clear needle-like prisms. It has a neutral reaction, does not reduce Fehling's solution, and is not colored brown by alkalies. Its analysis seems to indicate a formula C5H12O5, and Merck considers that it is a hitherto undescribed pentatomic alcohol, and calls it adonite. Whether it be identical with the adonidulcite announced in a preliminary communication by Podwyssotzki shortly before his death, Merck is not able to state, as no details of fusing point, formula, or chemical reactions were given by the former. (M. Bull., Jan., 1893.) E. Fischer (Ber. d. Chem. Ges., 1893, 633) confirms the formula C5H12O5 given by Merck, as well as the statement that it is a pentatomic alcohol; by oxidation with sodium hypobromite it is changed into ribose, C5H12O5, which treated with sodium amalgam again yields adonite.

The National Formulary description is as follows: "Glabrous, with the exception of the younger portions, which maybe slightly grayish-puberulent; stems from 15 to 50 cm. in length, thick, but soft and weak; shining, simple or branched, the branches mostly from near the base and similar to the main stem; naked below, except for some scale-like leaf-vestiges, densely leafy above; leaves from 2 to 4 cm. in length and two-thirds or more as broad, pinnately divided into several segments, the larger of which are again divided, the ultimate segments being narrowly linear, and acute; flowers terminal, yellow but usually drying to a cream color, from 3 to 6 cm. in breadth; sepals five, green or grayish-puberulent, more than half the length of the petals, oblong, obtuse, finely nerved; petals from five to twenty, oblong, obtuse, finely nerved; stamens indefinite; pistils numerous, in fruit forming an ovoid, obtuse, dense head of ovoid akenes, which are tipped with the very small, persistent styles. Odor faint; taste bitterish, afterward somewhat acrid. The powdered drug is grayish-green and, when examined under the microscope, exhibits numerous fragments of pith parenchyma, the cells with few simple pores, up to 0.05 mm. in width and 0.25 mm. in length; groups of long narrow sclerenchyma fibers, mostly with lignified walls from 0.005 to 0.007 mm. in thickness and having a few rounded or oblique simple pores; tracheae spiral or with bordered pores and up to 0.017 mm. in width; epidermal cells from the stem and petiole, elongated in surface view and with elliptical stomata, the latter about 0.064 mm. in length; fragments of the epidermal tissue from the lamina of the leaf, composed of finely striated cells with wavy, vertical walls; associated with broadly elliptical stomata, the latter up to 0.047 mm. in length; brownish colored fragments from the scales at the base of the stem, composed of elongated cells with somewhat rounded ends and yellowish-brown walls; starch grains and calcium oxalate crystals few or absent. Adonis yields not more than 12 per cent. of ash."

Adonidin belongs physiologically to the digitalis group. Although in Hare's experiments (T. G., 1886) the frog's heart was arrested in diastole. Cervello (A. E. P. P., xv) and De Guirlat found that the arrest is systolic. The pulse is slowed by stimulation of the inhibitory apparatus. In the experiments of Henrijean (B. A. R. B., 1909, xxiii, p. 363) in the early stages of the action, electrical stimulation of the pneumogastric nerve produced an unwonted degree of retardation of the pulse rate, which would indicate an increased excitability of the peripheral ends of the nerves. All investigators are in accord that the slowing of the pulse is to a large extent abolished by section of the vagi, so that the inhibitory influence must be largely also of central origin. There occurs also a pronounced rise of the blood pressure, which, according to Hare, is due partly to a stimulant action upon the heart, and partly to an effect upon the vasomotor mechanism. In the more exact experiments of Henrijean, vasoconstriction appeared only late in adonidin poisoning. After large toxic doses, the heart becomes irregular, and the blood pressure falls. According to Kakowski (A. I. P. T., xv, p. 21), adonidin differs from most of the other digitalis group in that it dilates the coronary arteries, while most of these drugs produce constriction.

Adonis vernalis was introduced as a cardiac tonic by Bubnow in 1879. Clinical experience confirms the conclusion of the pharmacologist, that it resembles digitalis in its action, and is a useful agent in the treatment of chronic heart disease. The advantages which have been claimed for it are, that it is more prompt in its action, and that it manifests less cumulative tendency than digitalis, but it appears to be less certain in its effect. Bechterew asserts that it is a useful remedy in epilepsy when used in conjunction with the bromides. The dose of adonis vernalis is from two to ten grains (0.12-0.6 Gm.), which may be given in the form of an infusion. The glucoside adonidin may be given in doses of one-twelfth to one-fourth of a grain (0.005-0.015 Gm.).

The Dispensatory of the United States of America, 1918, was edited by Joseph P. Remington, Horatio C. Wood and others.