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

  • Frederick Belding Power
Date:
[1908?]
Catalogue details

Licence: In copyright

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

    7/40 (page 5)
    Examination of the Steam Distillate. The distillate was extracted with ether, the ethereal liquid being dried with anhydrous sodium sulphate, and the ether removed. A small amount of an essential oil was thus obtained which, when dis¬ tilled under a pressure of 35 mm., passed over between 90 and i8oa C. It had a pale yellow color, a strong characteristic odor, and the following constants: d 20°/20° =09085; aD—40 52' in a e dcm tube. The amount of this essential oil was 3-5 grammes, cor¬ responding to 0 018 per cent, ot the weight of the drug. Examination of the Aqueous Liquid (/I). The aqueous liquid remaining in the steam distillation flask was separated from the previously mentioned soft resin, and, together with the washings from the latter, evaporated to a small volume. It then formed a very dark, syrupy liquid, which, on standing, de¬ posited a quantity of crystals amounting to about 40 grammes. These were separated, and washed with a little alcohol, when on further examination they were found to be entirely inorganic, and to consist of a mixture of potassium chloride and nitrate. The syrupy liquid was subsequently diluted with water, and treated with a slight excess of solution of basic lead acetate, when an abundant, deep yellow precipitate was produced. This was col¬ lected on a filter and washed with water, the washings being added to the filtrate. Basic Lead Acetate Precipitate.—This was suspended in water, decomposed with hydrogen sulphide, and the lead sulphide removed by filtration. The filtrate had an orange-yellow color and gave a greenish-brown coloration with ferric chloride, indicating the pres¬ ence of a small amount of tannic matter. When concentrated, it formed a dark brown syrup. As the latter deposited nothing of a crystalline character on standing, it was extracted with ether, and the ethereal liquid shaken with successive portions of a solution of sodium carbonate. The first two extractions with alkali were of a red color, and, when diluted, showed a blue fluorescence, whereas the subsequent extractions were colorless. The alkaline liquids were then acidified and extracted with ether, but only a trace of an amorphous, reddish substance was obtained. The original ethereal liquid which had been shaken with alkali was dried and the ether removed, but it gave practically no residue.