Preparations: Fluid Extract of Condurango
The bark of Gonolobus Cundurango, Triana (Marsdenia Condurango, Reichenbach).
COMMON NAMES: Eagle vine, Mata-peroo.
Botanical Source.—This plant is a twining vine, having opposite cordate leaves, which are cuspidate and sinuately narrowing on the margins, hairy above and silky and tomentose underneath. The flowers are borne in loose cymes. The peduncles and petioles are covered with a pale, grayish pubescence, and the stem, which reaches a thickness of from 1 to 5 inches and a great height, has a greenish-gray bark, which, when cut or bruised, exudes a viscid, milky juice.
History.—Cundurango was introduced, in 1871, in rather an official manner, having been received by the State Department at Washington, from the Minister of Ecuador. The drug was accompanied by certificates from two physicians of the province of Loja, attributing to the bark great power to cure cancer, syphilis, etc. The statements were supported by a letter from our Minister at Ecuador. An analysis of the plant (see below) threw but little light upon the subject, as substances common to most plants only were found. Shortly after it came into notice, a note from Mr. Dan. C. Robbins, of New York, to the editor of the Amer. Jour. Pharm., stated that Mr. Wiehl, United States Consul at Guayaquil, had favored him with specimens of the flowers, leaves, and fruit of the true condurango vine. It was stated that the name condurango meant "Eagle vine," or "Condor-vine," and that there were some 6 varieties, 3 of which were used in medicine, and were known in Spanish by names signifying dog-killer, big fruit, and little fruit. The "dog-killer," which is true condurango, is a tropical climbing vine, seeking the highest trees of the cinchona region of South America. Doubtless, the market is supplied with barks of several species of climbing plants.
Description and Chemical Composition.—The bark only is recommended for use. It is in thin pieces, of a whitish or yellowish color, in appearance reminding one of the bark of ptelea root. The taste is slightly bitter and aromatic. Thomas Antisell (Amer. Jour. Pharm., 1871) found in 100 parts of condurango bark: Moisture (8 per cent), ash (12 per cent), fatty matter (7 per cent), yellow resin, soluble in alcohol (2.7 per cent), gum and glucose from starch (0.5 per cent), tannin and coloring matters (12.6 per cent), cellulose, lignin, etc. (63.5 per cent). In 1872, Vulpius observed a precipitate that formed upon warming of a clear, aqueous infusion of the bark, and which suggested the presence of a substance related to Tanret's vincetoxin, from the root of Asclepias vincetoxicum. In 1885, Vulpius pronounced the glucosidal nature of this substance, which he named condurangin, admitting, however, that it might not be a simple body. A 2 per cent solution in water has the property of gelatinizing upon warming, and becoming clear again when cold. Condurangin, while a glucosid, also reacts with alkaloidal reagents. Vulpius resolved it into two substances, one soluble in water, and insoluble in ether, and another with these solubilities reversed (Archiv. der Pharm., 1885, p. 299).
Kobert and Jukna (1888) investigated condurangin both chemically and physiologically, and Carrara (1892) examined Vulpius' decomposition products, establishing formulae and melting points for both. He also announced the presence of a new glucosid of the formula C40H74O6, having a melting point of 112° C. (233.6° F.), insoluble in ether, sparingly soluble in cold alcohol, and very slightly soluble in water. It is not precipitated by Mayer's reagent, nor with iodine in solution of iodide of potassium. The same observer found conduransterin (C30H50O2), melting point 52° C. (125.6° F.), a body related to cholesterin. It is contained in the ether solution of the precipitate formed in the cooled alcoholic extract. Cinnamic acid was also isolated from the mother-liquors. Schroff and Schmiedeberg, (Med. Chir. Rundschau, 1871-2) believed that an alkaloid, resembling strychnine in its action, must be present in the bark, and Flückiger, in 1882, obtained minute quantities of an alkaloid.
Action, Medical Uses, and Dosage.—This agent, at one time so highly lauded as a positive remedy for cancer and syphilis, is rarely employed at the present time, and should it possess any valuable therapeutic virtues, they are not likely to be ascertained for some time to come, as the exaggerated statements and misrepresentations attending its introduction have led the profession to regard it with suspicion and incredulity. It is probable, however, that it has a tonic effect in gastric debility, and especially relieves pain in the stomach. Condurangin, according to Kobert, acts upon the central nervous apparatus, producing in animals impairment of appetite, vomiting, ptyalism, muscular weakness, convulsions and paralysis. Of condurango a decoction (bark ℥ss to aqua Oj boiled down to Oss.) may be given in tablespoonful doses 3 times a day; fluid extract, 5 to 30 drops.