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.

    33/40 (page 31)
    An aqueous solution containing 1*7680 grammes of substance in 25 c c. gave aD — 40 47' in a I dcm. tube, whence [a]D — 67.63°. Treatment with Dilute Sulphuric Acid.—A quantity (25 grammes) of the above-described material was dissolved in 250 c.c. of 5 per cent, aqueous sulphuric acid, and the solution heated for about four hours in a reflux apparatus. It was then distilled with steam, and the distillate extracted with ether, when a very small quantity of a neutral oil was obtained, which was similar in character to that afforded by the treatment of the alcohol extract of the original resin with dilute sulphuric acid. After extraction with ether, the distillate still contained a small quantity of acid which was converted into a barium salt, and this gave reactions indicating the presence of formic and butyric acids. The liquid remaining in the distilla¬ tion flask, after the removal of the volatile substances by steam, and being allowed to cool, contained a considerable quantity (5*5 grammes) of a solid crystalline product, part of which was in the form of a brownish cake. It was therefore extracted with ether, the ethereal solution dried, and the solvent removed. The product thus obtained was dissolved in alcohol, the solution mixed with purified sawdust, and, after thoroughly drying the mixture, it was extracted successively in a Soxhlet apparatus with (a) light petro¬ leum and (b) ether. {a) Petroleum Extract.—This liquid deposited a small amount of a crystalline substance in the form of handsome rosettes, which were associated with a little oily matter. After the complete removal of the solvent, the substance was crystallized from 50 per cent, alcohol, and finally from a large volume of hot water. It was thus obtained in handsome, colorless needles, melting at 69-70° C., and on analysis gave the following result : 0*0676 gave 01646 C02 and 0 0670 H20. C — 66 4; H = ii-o. Ci2H2A requires C = 66 6; H = in per cent. The silver salt of the acid was also prepared and analyzed. 0*2042 of salt gave on ignition 00678 Ag. Ag = 33*2. Ci2H,303Ag requires Ag =33*4 per cent. The aboveTdescribed substance is thus seen to agree in composi¬ tion with a hydroxylaiiric acid. A hydroxylauric acid has previously been obtained by Hoehnel1 1 Archiv der Pharm., 1896, 234, p. 670.