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.

    37/40 (page 35)
    the ether extract, but no crystalline acid could be isolated. When heated with 5 per cent, alcoholic sulphuric acid, it likewise afforded products which were very similar to those obtained from the ether extract of the resin. IV. Ethyl Acetate Extract.—This represented 23 8 per cent, of the total resin. From this extract there was isolated a very small amount of a new crystalline alcohol, ipuranol, having the formula C23H3802(0H)2, and melting at 285-290° C. Its acetyl derivative formed pearly leaflets, melting sharply at 160° C. The extract, when fused with potassium hydroxide, as also when heated with 5 per cent, alcoholic sulphuric acid, yielded products analogous in character to those obtained from the above-described ether and chloroform extracts of the resin by the same treatment. V. Alcohol Extract.—This represented about one-half of the total crude resin. When purified by means of animal charcoal, it was obtained in the form of a perfectly white powder, which, after dry¬ ing at 110° C., melted somewhat indefinitely between 150 and 160° C. Its specific rotatory power was [a]D — 51-64°. When heated with 5 percent, alcoholic sulphuric acid, this extract like the preceding ones, yielded a small amount of a neutral oil, formic, butyric and higher volatile acids, and a non-volatile acid which was readily soluble in water, together with glucose. In addition to these products, however, it afforded a quantity of a new dihydroxymonocarboxylic acid, C13H25(0H)2-C02H, designated ipurolic acid, which crystallizes in fine, colorless, silky needles, melt¬ ing at 100-101° C. Several derivatives of this acid have been pre¬ pared, such as its sodium salt, CjjHo^OHyCCbNa^O; silver salt, Ci3H.5(0H)2C02Ag (m. p. 160° C.); methyl ester, C^H.^OHJy COoCH3 (m. p. 68-69° C.); the monomethyl derivative of the methyl ester, C13H25(0H)(0CH3)C02CH3 (m. p. 64-65° C.); and the diphenyl- urethane of the methyl ester, C13H.v>(0 C0-NH-C6H5)2*C02CH3, melt¬ ing at 96-97° C. The above-described alcohol extract of the resin, when treated in alcohol solution with barium hydroxide, yielded, besides formic and butyric acids, a quantity of optically active valeric acid (^-methyl- ethylacetic acid), b. p. 174-176° C.; [a]D -j- 17*95°, together with a mixture of acids which was readily soluble in water. This mix¬ ture of acids was extracted successively with ether, chloroform and ethyl acetate, when small amounts were removed by each of these solvents, the larger proportion being soluble only in alcohol. These