Chemical examination of the root of ipomoea orizabensis / by Frederick B. Power and Harold Rogerson.

  • Frederick Belding Power
Date:
[1912?]
Catalogue details

Licence: In copyright

Credit: Chemical examination of the root of ipomoea orizabensis / by Frederick B. Power and Harold Rogerson. Source: Wellcome Collection.

    13/30 (page 11)
    alkaline liquid thug obtained was acidified and extracted with ether, the ethereal liquid being washed, dried, and the solvent evaporated, when a quantity of fatty acids remained. Identification of the Fatty Acids. The above-mentioned mixture of fatty acids was distilled under diminished pressure, when it passed over between 220° and 255°/ 15 mm. as a light, yellow oil, and amounted to 18 grams. The acids were first separated into liquid and solid portions by means of their lead salts. The Liquid Acids.—These acids, when distilled under diminished pressure, passed over between 220° and 235°/15 mm. as a pale yellow oil, and amounted to 9'2 grams. An analysis and a deter¬ mination of the iodine value gave the following results: 0 1830 gave 0'5160 C02 and 0 1862 H20. C = 76 9; H = ll*3. 0‘5154 absorbed 0’8226 iodine. Iodine value = 159*6. C18H3402 requires C = 76'6; H = 121 per cent. Iodine value = 90'l. C18TI3o02 „ C = 77T; H = 11’4 „ „ Iodine value = 181'4. From these results it would appear that the liquid acids consisted chiefly of linolic acid, with a relatively small proportion of oleic acid. This was further confirmed by the oxidation of a portion (8 grams) of the mixture with potassium permanganate, according to the method described by Lewkowitsch {Chemical Technology and Analysis of Oils, Fats, and Waxes, 1904, I., p. 360). The chief product of the oxidation wTas tetrahydroxystearic acid, melting at 158—160°. (Found, C=61'9; lT-10'3. Calc., C = 62'l ; H = 103 per cent.) The Solid Acids.—These acids, when distilled under diminished pressure, passed over between 220° and 260°/15 mm. as a light, yellow oil, which solidified on cooling to a crystalline mass, and amounted to 8 grams. The mass was recrystallised from ethyl acetate, when a product was obtained which melted at 53—55°: 0-2528 gave 0'6948 C02 and 0 2870 H30. C-74 9; 11 = 12 6. ClcH3o02 requires C = 75 0; H = 125 per cent. 018H^02 „ C = 76*1; H = 12-7 „ „ The solid product thus appeared to consist of a mixture of palmitic and stearic acids, the former predominating. II.—Ethereal Extract of the Resin. This extract, after the removal of the solvent, was a dark resinous mass, which could easily be reduced to a light brown powder, and was stable in the air. It amounted to 725 grams.