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.

    12/30 (page 10)
    acetate and dilute alcohol. The substance was thus obtained in handsome, pearly leaflets, melting at 135—136°, and it gave the colour reaction of the phytosterols: 0*3192, on heating at 110°, lost 0*0153 IT20. H20 = 4'8. 0-1072* gave 0'3292 C02 and 0*1144 I120. 0 = 83-7; H = ll*8. C27H4G0,H20 requires H20 = 4*5 per cent. C27H460 requires C—83*9; H = ll*9 per cent. A determination of the specific rotatory power gave the following result: 0*1934,* made up to 20 c.c. with chloroform, gave aD — 0*39/ in a 2-dcm. tube, whence [a]D —33*6°. The acetyl derivative was prepared by heating a little of the substance with acetic anhydride. It separated in flat needles, melting at 122—124°. The above-described substance was thus definitely identified as a phytosterol, and, with the exception of the slightly higher melting point of its acetate, it agrees in character with verosterol (Trans., 1910, 97, 1951). Isolation of Cetyl Alcohol, C16H340. The alcoholic mother liquors remaining from the separation of the above-described phytosterol were evaporated, and the residue distilled under diminished pressure. The distillate was collected in three fractions, which passed over respectively at 190—200°, 200—220°, and 220—300°/15 mm. The first two fractions were united and recrystallised, first from light petroleum and then from ethyl acetate. A quantity (2*5 grams) of cetyl alcohol was thus obtained, which separated in small, colourless leaflets, melting at 50—51°. (Found, 0=79-0; H = 14*0. Calc., C = 79 3; H = 14T per cent.) The third of the above-mentioned fractions, which was very small in amount, was crystallised from ethyl acetate, when it separated in lamime, melting at 55—56°. It apparently consisted of a mixture of cetyl alcohol and some higher alcohol of that series. The alkaline liquid, from which the above-described products had been removed by extraction with ether, was acidified, and again extracted with ether. The ethereal liquid was first shaken with aqueous ammonium carbonate, which removed a small amount (1*0 gram) of the previously-described 3 :4-dihydroxycinnamic acid (m. p. 222—225°). It was next extracted with a solution of sodium carbonate, which removed all of the dissolved substance. The * Anhydrous substance.