BOTANICAL CHARACTERISTICS.—A woody climber, ascending to the tops of high trees, from which it hangs in festoons. Flowers in terminal cymes, gamopetalous, the lobes prolonged into long, tail-like points, often 8 or 9 inches long. Fruit two long follicles.
SOURCE.—The genus Strophanthus contains about 20 species, native of Africa and Asia, where it is probable that more than one of them are used for the preparation of arrow-poison.
DESCRIPTION OF DRUG.—Lance-ovoid, flattened and obtusely edged; from 7 to 20 Mm. in length, about 4 mm. in breadth and about 2 Mm. in thickness; externally, of a light fawn color, with a distinct, greenish tinge, silky lustrious from a dense coating of closely appressed hairs, (S. Kombe); or light to dark brown, nearly smooth and sparingly hairy (S. hispidus), bearing on one side a ridge running from about the center to the summit; fracture short and somewhat soft, the fractured surface whitish and oily; odor heavy when the seeds are crushed and moistened; taste very bitter. U.S.P. IX.
Powder.—Characteristic elements: See Part iv, Chap. I, B.
TEST U.S.P.—If made into the official tincture and assayed biologically the minimum lethal dose should not be greater than 0.00006 mil of tincture, or the equivalent in tincture of 0.0000005 Gm. of ouabain, for each gramme of body weight of frog. Preserve Strophanthus in tightly closed containers, adding a few drops of chloroform or carbon tetrachloride, from time to time, to prevent attack of insects.
CONSTITUENTS.—Its medical properties depend upon an intensely bitter glucoside, strophanthin, C32H48O16 (anhydrous), 2 to 2.5 per cent., choline, trigonelline, kombic acid, resin, mucilage, and a fixed oil are also present. Ash, not to exceed 5 per cent.
OUABAIN, CRYSTALLIZED.—Crystallized Strophanthin.—G. Strophanthin Thorns. C30H46O12 + 9H2O. A glucoside, obtained from Acocanthera ouabaio by Arnaud, or, as now commonly prepared, from Strophanthus gratus, in which case it is also called crystallized strophanthin, or g-strophanthin Thorns. (The official strophanthin is methyl ouabain C31H48O12.) Recent investigation shows that this alkaloid varies in proportion to water of crystallization.
Preparation of Strophanthin.—Treat powdered seeds with acidulated (HCl) alcohol; evaporate to soft extract; treat with water. The aqueous solution containing tannate is treated with lead oxide, and from the purified aqueous solution white crystals are obtained.
ACTION AND USES.—Used in all forms of cardiac disease to supplant digitalis, but is not generally regarded as its equal. It has a diuretic action similar to digitalis through its action on the circulation, and also by direct promotion of urinary secretion, and is especially indicated in cardiac dropsy as being superior to digitalis; given in the form of tincture. Dose: 1 gr. (0.065 Gm.).
- OFFICIAL PREPARATION.
- Tinctura Strophanthi (10 per cent.) Dose: 4 to 8 drops (0.25 to 0.50 Mil).