The constituents of the rhizome of apocynum androsæmifolium / by Charles W. Moore.

  • Moore, Charles W
Date:
[1909?]
Catalogue details

Licence: In copyright

Credit: The constituents of the rhizome of apocynum androsæmifolium / by Charles W. Moore. Source: Wellcome Collection.

    5/22 (page 736)
    Distillation o f the Extract with Steam. Separation of an Essential Oil. A quantity (5 kilograms) of the above-mentioned extract, represent¬ ing about 19 kilograms of the rhizome, was mixed with water, and steam passed through the mixture for several hours. The distillate, which amounted to about 10 litres, contained some drops of oil floating on the surface. It was thoroughly extracted with ether, and the ethereal liquid shaken with a dilute solution of ammonium carbonate. On acidifying this alkaline liquid, a small quantity of an oily acid separated, which was removed by ether and distilled under the ordinary pressure, when it passed over between 210° and 215° aa an almost colourless, viscid liquid, and amounted to about 2'0 grams. It was converted into the ammonium salt, from which five fractions of silver salt were precipitated. The analysis of these salts showed that the acid consisted chiefly of an octoic acid. The ethereal liquid which had been extracted with ammonium carbonate, as above described, was shaken with successive portions of a dilute solution of potassium hydroxide. The alkaline liquids thus obtained were united, acidified, and extracted with ether, when a small amount (1*2 grams) of a crystalline substance, melting at 112—114°, was obtained. This proved to be identical with a substance which was afterwards obtained in larger quantity, and was shown to be acetovanillone. The ethereal liquid which had been extracted with potavssium hydroxide, as above described, yielded, after removing the solvent, a small quantity of an essential oil, which distilled between 130° and 250°. It was a pale yellow liquid, possessing a strong persistent odour and the following constants : d 12°/12° = 0’948 ; -t-0°50' in a 1-dcm. tube. The amount of this essential oil was 3'0 grams. It gave a strong furfuraldehyde reaction. Non-volatile Constituenits of the Extract. After the distillation of the extract with steam, as above described, there remained a quantity of a brown resin (^1) and a dark-coloured aqueous liquid. The latter was separated by filtration while still hot,, and the brown resin repeatedly treated with boiling water until nothing further was removed. The aqueous liquid and washings from the brown resin were united and kept for several days, when a quantity of a brown resin {B) slowly separated. This was removed from the liquid and thoroughly washed with cold water, the washings being added to the aqueous liquid, which may be designated as {€).