The constituents of the flowers of Trifolium incarnatum / by Harold Rogerson.

  • Rogerson, Harold.
Date:
[1910?]
Catalogue details

Licence: In copyright

Credit: The constituents of the flowers of Trifolium incarnatum / by Harold Rogerson. Source: Wellcome Collection.

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    856 grams. It was treated with hot alcohol, when a portion (88 grams) remained undissolved in the form of a hard, brown solid. For the examination of the soluble portion of the resin, a quantity (192 grams) representing 1*59 kilograms of the original alcoholic extract was employed. This was mixed with purified sawdust, the thoroughly dried mixture being then successively extracted in a Soxhlet apparatus with petroleum (b. p. 35—50°), ether chloroform, ethyl acetate, and alcohol. Petroleum Extract of the Resin. This extract was a soft, dark green mass, amounting to 157 grams. It was dissolved in ether, and the ethereal liquid extracted with a solution of ammonium carbonate, which, however, removed nothing. On subsequently shaking the ethereal liquid with successive portions of aqueous potassium carbonate, a quantity of material was removed. The alkaline liquids thus obtained were therefore acidified and extracted with ether, when a small amount of substance remained undissolved. This substance, which was very sparingly soluble in ether, was collected, dissolved in dilute alcohol, and the solution treated with animal charcoal. On subsequently concentrating the solution, the substance separated in glistening laminae, which melted and decomposed at 235°, but the amount was not sufficient for its further examination. The ethereal liquid, from which the above-mentioned substance had been removed by filtration, was washed, dried, and the solvent removed. A quantity of fatty acids was thus obtained, together with some resinous matter. In order to purify the acids, they were converted into their ethyl esters, and the latter distilled under diminished pressure. The esters were then hydrolysed, and the regenerated acids distilled under diminished pressure, when they passed over between 220° and 280°/15 mm. as a viscid liquid, which solidified on cooling to a white, crystalline mass. The acids thus obtained amounted to 16*5 grams, and they were examined in connexion with a similar product obtained from the petroleum extract after its hydrolysis. The ethereal liquid which had been extracted with potassium carbonate, as above described, was subsequently shaken with a solution of sodium hydroxide, which, however, removed only a little resinous material. II yd roly sis of the Petroleum Extract. After extracting the ethereal solution of the petroleum extract with alkalis, as above described, the ether was evaporated, when a