Source, Etc

The meadow saffron, Golchicum autumnale, Linne (N.O. Liliaceoe), is widely distributed over Europe, and abundant in some parts of England in moist meadows and pastures. It produces in the autumn a conspicuous, reddish purple flower that springs from the side of an enlarged contracted stem (corm) several centimetres below the surface of the ground. The ovary is superior and lies at about the same depth in the ground. The leaves appear soon after the flower, and attain in the spring a length of 20 or 25 cm. The ovary is then raised to the surface by the elongation of the peduncle, after which the leaves wither. The fruit, a three-celled capsule, ripens in the summer, dehiscing septicidally and disclosing numerous seeds which, when quite fresh, are pale in colour, but darken as they dry, becoming at the same time covered with a saccharine exudation, as much as 5 per cent, of glucose having been found on them. These were introduced into medicine about 1820 to replace the corm, which was considered uncertain in action.

Fig. 100.   Colchicum autumnale. A, flowering plant, much reduced. B, lower part of the same, natural size.

Fig. 100. - Colchicum autumnale. A, flowering plant, much reduced. B, lower part of the same, natural size. C, corm, cut vertically: k, corm; k\ young corm for the next year; k", bud destined to reproduce the plant after has developed. D, portion of the same, showing h, the leaves enveloping the corm. E, upper part of perianth, halved. F, ovary, o, with the three styles. G, ovary, magnified. H, fruit. J, the same, cut transversely, showing the seeds. K, seed, magnified. L, the same, cut to show the embryo, e. (Luerssen).

Description

Colchicum seeds are small, very hard, and of a dull dark reddish brown colour. They are about 2.5 mm. in diameter and nearly spherical, the remains of a thick funiculus rendering them somewhat pointed. Under a lens the surface is seen to be rough from the presence of minute pits. They are extremely hard and tough, and are difficult to cut until they have been soaked in water; the section exhibits a yellowish, oily endosperm, in which, near the margin and removed from the hilum, the minute embryo is embedded. They are odourless, but have an unpleasantly bitter taste.

The student should observe

(a) The rough surface and hard nature of the seed,

(b) The remains of the thick funiculus; and should compare them with

(i) Black mustard seeds, which are smaller,

(ii) Henbane seeds, which are reniform in outline.

Constituents

All parts of the plant contain the alkaloid, colchicine, which possesses weak basic properties. The seeds contain from 0.02 to 0.8 per cent., but a good sample of the drug should yield not less than 0.5 per cent. The seeds also contain a resin, colchicoresin, and about 6 per cent, of fixed oil. They yield about 3 per cent, of ash.

Colchicine, C22H15N06, crystallises in pale yellow needles melting at 155° to 157° and yields a crystalline compound, C22H15N06.2CHCl3, with chloroform. The alkaloid is very soluble in cold water, alcohol, and chloroform, but only slightly in ether. Chloroform removes it from an acid as well as from an alkaline aqueous solution; boiled with dilute mineral acids it yields colchiceine and methyl alcohol. Colchicine has also been found in the root of Gloriosa superoa, Linne.

Assay

The seeds may be assayed by the process devised by Farr and Wright.1

Uses

Colchicum is chiefly used to relieve the pain and inflammation and shorten the duration of acute gout and certain gouty affections. Its action depends upon the alkaloid colchicine. Colchicine has a marked action upon plain muscle, especially that of the intestine, producing diarrhoea and vomiting. In large doses it produces death from failure of the respiration.

Adulteration

Colchicum seeds are said to be liable to adulteration by the fraudulent addition of glucose.

1 Yearbook of Pharmacy, 1911, p. 23.