The constituents of colocynth / by Frederick B. Power and Charles W. Moore.

  • Frederick Belding Power
Date:
[1910?]
Catalogue details

Licence: In copyright

Credit: The constituents of colocynth / by Frederick B. Power and Charles W. Moore. Source: Wellcome Collection.

    12/16 page 108
    Hydrolysis of the Fatty Oil. Isolation of a Phytosterol, C20H34O. A quantity (150 grams) of the oil was hydrolysed by boiling with alcoholic potassium hydroxide, the alcohol removed, water added, and the alkaline solution of potassium salts extracted with ether. The ethereal liquid was washed, dried, and the solvent removed, when a small quantity of a crystalline substance was obtained. This was distilled under diminished pressure, after which it was crystallised from a mixture of dilute alcohol and ethyl acetate, when it separated in colourless, glistening plates, melting at 158—160°. The amount of substance so obtained was 0*3 gram : 0-1700 gave 0-5154 C02 and 0-1724 H20. C = 827 ; H = ll*3. C20H34O requires C = 82 -8 ; H = 1T7 per c ent. This substance was evidently a phytosterol, and it yielded the colour reactions of this class of compounds. A determination of its specific rotatory power gave the following result: 0'2473, made up to 20 c.c. with chloroform, gave aD +0°12' in a 2-dcm. tube, whence [a]D +8*1°. The acetyl derivative, when crystallised from acetic anhydride, separated in glistening plates, melting at 167—170°. The Fatty Acids. The alkaline solution of potassium salts, which had been extracted with ether as above described, was acidified and again extracted with ether, the ethereal solution being washed, dried, and the solvent removed. The fatty acids thus obtained amounted to 87 per cent, of the weight of the oil. When distilled under diminished pressure, they passed over between 240° and 245°/15 mm. as a viscous liquid, which solidified on cooling to a soft, nearly colourless mass. A determination of the constants of the total acids gave the following t O & results: Melting point (complete fusion), 29*5—32°; specific gravity, 50°/50° = 0-8910 ; neutralisation value, 195*6; iodine value 131T. These constants, both for the fatry oil and the total acids obtained therefrom, are in fairly close agreement with those recently recorded by Grimaldi and Prussia (Chem. Zeit., 1909, 33, 1239). The last- mentioned investigators had, however, extracted the colocynth seeds by means of carbon tetrachloride, and describe the oil as having a reddish-yellow colour with a slight green fluorescence. ^Summary. The results of the preceding investigation may be summarised as follows :
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