Chemical examination of Ipomoea purpurea / by Frederick B. Power and Harold Rogerson.

  • Power, Frederick B. (Frederick Belding), 1853-1927.
Date:
[1908?]
Catalogue details

Licence: In copyright

Credit: Chemical examination of Ipomoea purpurea / by Frederick B. Power and Harold Rogerson. Source: Wellcome Collection.

    35/40 (page 33)
    acid, which was obtained by the above-described treatment was present in the extract in the form of a glucoside, the latter would have yielded on hydrolysis an amount of glucose corresponding to 3 8 grammes. It is evident, therefore, that practically the entire amount of glucose found resulted from the hydrolysis of the gluco- sides of ipurolic and hydroxylauric acids. On the other hand, as the 5-5 grammes of crystalline acids obtained would correspond to about 9 grammes of the respective glucosides, and as the weight of alcohol extract of the hydrolyzed resin which was treated with sulphuric acid was 25 grammes, it follows that this extract con¬ tained a considerable proportion of a substance' which was not a glucoside. The liquid which had been freed from sulphuric acid by means of baryta, as described above, contained, besides glucose, a consider¬ able quantity of a barium salt, but this did not separate, even when the liquid was concentrated to the consistency of a thick syrup and allowed to stand for a long time. The acid contained in this salt was evidently highly oxygenated, and doubtless represented that constituent of the alcohol extract of the hydrolyzed resin which was not glucosidic in character. Numerous attempts were made to isolate this soluble organic acid, but without success. A deter¬ mination of the amount of barium in the liquid showed, however, that the soluble non-glucosidic acid yielded by 25 grammes of the alcoholic extract of the hydrolyzed resin corresponded to 4-15 grammes Ba. SUMMARY AND PHYSIOLOGICAL TESTS. As the details of the preceding investigation are necessarily some¬ what extended, it appears desirable that the more important results should be briefly summarized. The material employed, consisting chiefly of the aerial stems of Ipomcea purpurea, Roth, was kindly supplied to us by Mr. J. Medley Wood, Director of the Natal Botanic Gardens, Durban, South Africa. When extracted with alcohol, and the resulting extract distilled with steam, an amount of essential oil was obtained cor¬ responding to 0-018 per cent, of the weight of the drug. This essential oil was a pale yellow liquid, having a strong, characteristic odor and the following constants: d 20°/200 = 0-9085 ; aD — 4°52' in a 1 dcm. tube. After the removal of the volatile substances