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.

    36/40 (page 34)
    by distillation with steam, there remained in the distillation flask a dark-colored aqueous liquid and a quantity of a soft resin. The aqueous liquid contained a considerable quantity of potassium chloride and nitrate, together with tannic and coloring matters, and yielded glucose on heating with a dilute mineral acid. The most important product yielded by Ipomcea purpurea is the above-mentioned resin, the amount of which corresponded to 4-8 per cent, of the weight of the drug, and of this resin 15-5 per cent, was soluble in ether. The crude resin, which, when dry, can be reduced to a dark brown powder, is, however, an exceedingly com¬ plex mixture, as has been shown by the results of its successive extraction with the following solvents: (I) light petroleum, (II) ether, (III) chloroform, (IV) ethyl acetate, and (V) alcohol. The examination of these various extracts has, moreover, rendered it evident that each of them is likewise of complex composition. The crude resin is optically active. After treatment with animal charcoal to deprive it of coloring matter, it was found to have a specific rotatory power, in alcoholic solution, of [a]D — 50*95°. The products obtained from the various extracts of the resin were as follows: I. Petroleum Extract.—This represented 8 per cent, of the total resin. After treatment with an alcoholic solution of potassium hydroxide, it yielded pentatriacontane, C35H72 (m. p. 74-75° C.); a phytosterol, C27H460, H20 (m. p. 132-133° C.; [<%]D — 32*1°); formic, butyric, and higher volatile acids; stearic, and apparently some pal¬ mitic acid, with a very small amount of an unsaturated oily acid. II. Ether Extract.—This represented 7-3 per cent, of the total resin. When fused with potassium hydroxide it yielded formic and butyric acids, a mixture of higher volatile acids, and a very small amount of a crystalline acid, melting at 103-104° C., which was apparently azelaic acid, C;)H1604, together with a trace of substance giving the catechol reaction. The extract, when heated with 5 per cent, alcoholic sulphuric acid, yielded, besides a quantity of resin, a small amount of a neutral oil, having a pleasant odor, together with formic, butyric and higher volatile acids, a readily soluble non-vola¬ tile acid, and glucose. III. Chloroform Extract.—This represented 9*8 per cent, of the total resin. When fused with potassium hydroxide, it yielded pro¬ ducts analogous to those obtained under the same conditions from