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.

    6/40 (page 4)
    In order to determine the value of this factor in connection with the resin under investigation, the method suggested by Guigues was employed. About 2*5 grammes of the crude resin were dissolved in 50 c.c. of alcohol, and the solution boiled with successive small portions of animal charcoal until it became practically colorless. The rotation of this liquid was then observed in a I dcm. tube, after which 10 c.c. of the liquid were evaporated to dryness, the resi¬ due dried at 105 —110° C., and weighed. The initial rotation in a f dcm. tube having been found to be —42', and as the amount of solid substance in 10 c.c. of the liquid was 0*1374 gramme, the specific rotatory power of the resin is [a]D — 50*95°. Preliminary Extraction of the Crude Resin zvith Different Solvents. In order to ascertain the general character of the crude resin, an amount of the latter obtained from 100 grammes of the drug (4*8 grammes) was dissolved in alcohol, mixed with purified sawdust, and the thoroughly dried mixture extracted successively in a Soxhlet apparatus with various solvents. The percentages of extract, dried at £ io° C., were as follows: Per cent. Petroleum (b. p. 40-60° C.) extracted. 8.0 lEther “ 7*3 Chloroform “ 9*8 Ethyl acetate “ 23*8 Alcohol “ 490 Loss. 2*1 100*0 For the further complete examination of the drug a quantity {43*4 pounds = 19*6 kilograms) of the ground material was com¬ pletely extracted with hot alcohol. The extract thus obtained, after the removal of the greater portion of the alcohol, was brought into a large flask, some water added, and the mixture distilled in steam until volatile products ceased to pass over. A turbid distillate was thus obtained, from which a few oily drops separated on the surface. After this operation there remained in the distilling vessel a dark- colored, aqueous liquid (A), which possessed an agreeable, fruity ©dor, and a quantity of soft, very dark greenish resin (B), which was thoroughly washed with warm water and the washings added to the aqueous liquid.