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.

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    The aqueous distillate which had been extracted with ether still contained a small amount of acid, which was converted into a barium salt, and this yielded reactions indicating the presence of formic and butyric acids. After the removal of the volatile products of hydrolysis by dis¬ tillation with steam there remained in the distillation flask a quantity of greenish-black resin and a dark-colored, aqueous liquid, which were separated by filtration. From the resinous substance nothing of a crystalline nature could be obtained. The acid, aqueous liquid was first extracted with ether, which removed only a very small quantity of a syrupy substance, and the sulphuric acid then removed by means of baryta. After filtration the liquid was concentrated, when about 3 grammes of a syrup were obtained which instantly re¬ duced Fehling’s solution on heating, and when treated with phenyl- hydrazine acetate yielded ^-phenylglucosazone, thus indicating the presence of glucose. This syrupy liquid also contained a small amount of a readily soluble organic acid. III. Chloroform Extract of the Resin. This extract formed a brown mass, which could readily be pow¬ dered. Its solution in chloroform was first repeatedly extracted with a solution of sodium carbonate, but this removed only a very small amount of an amorphous, acidic substance. Fusion with Potassium Hydroxide.—Twenty grammes of the resin were fused with 120 grammes of potassium hydroxide, the operation being conducted in the same manner as has been described in con¬ nection with the ether extract. The cooled mass, when dissolved in water, acidified with sulphuric acid, and distilled with steam, yielded a small amount of oily acid. This was extracted with ether, con¬ verted into an ammonium salt, and from the latter three fractions of silver salt were prepared and analyzed : (I) 0-1364 of salt gave on ignition 00516 Ag. Ag = 37-8 (II) 0 0644 “ “ “ 00260 Ag. Ag =r 40-4 (III) 0-0494 “ “ “ 0-0206 Ag. Ag = 4i*7 CC)H]702 Ag requires Ag — 40 7 per cent. CuH2i02 Ag “ Ag == 36 9 per cent. The volatile acids remaining in the distillate after extraction with * ether were neutralized with baryta, when about 2 grammes of a