Chemical examination of Ornithogalum thyrsoides / by Frederick B. Power and Harold Rogerson.

  • Power, Frederick B. (Frederick Belding), 1853-1927
Date:
[1910?]
Catalogue details

Licence: In copyright

Credit: Chemical examination of Ornithogalum thyrsoides / by Frederick B. Power and Harold Rogerson. Source: Wellcome Collection.

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    (boiling-point, 35-50°) ; II. ether ; III. chloroform ; IV. ethyl acetate ; and V. alcohol. I. Petroleum Extract. This extract, after the complete removal of the solvent, formed a soft, green solid, and amounted to 47 Gm. It was dissolved in a large volume of ether, when a small quantity of a sparingly soluble substance separated. The latter was found to consist chiefly of pentatriacontane, with a trace of a fatty acid. The respective hydrocarbon was subsequently isolated in larger amount. The ethereal liquid from which the solid substance had separated was afterwards shaken with a solution of ammonium carbonate, but this removed nothing. It was then shaken with several successive portions of aqueous sodium carbonate, the resulting alkaline liquids being acidified and extracted with ether. On removing the ether a quantity (20 Gm.) of a solid acid was obtained, and this was distilled under 15 Mm. pressure, when it passed over between 240° and 280°. It was crystallised from ethyl acetate, when it melted at 60°-61°, and gave the following result on analysis :— 0G140 gave 0'3134 C02 and 0 1302 H20. C - 74‘9 ; H = 12'7. Ci6H3202 requires C = 75'0; H = 12‘5 per cent. A portion of the acid was converted into a silver salt, and the latter analysed. 0’2840 of salt gave on ignition 00834 Ag. Ag = 29'4. Ci6Hsi02 Ag requires Ag — 297 per cent. The above-described substance was thus identified as pal¬ mitic acid. The ethereal liquid, which had been treated with ammonium and sodium carbonates, as above described, was shaken with a 10 per cent, solution of sodium hydroxide, but this only removed a further small amount of palmitic acid. It was subsequently washed, dried, and the ether evaporated, when a residue was obtained which amounted to 25 Gm. This product was hydrolysed by boiling for six hours in a reflux apparatus with an alcoholic solution of 7'5 Gm. of potassium hydroxide, after which the alcohol was removed, water added, and the alkaiine liquid repeatedly extracted with ether. The ethereal liquid was dried and the solvent evaporated, when a viscid liquid was obtained, which became solid on cooling. This was dissolved in about 600 C.c. of hot alcohol, and the solution allowed to cool, when a quantity of solid separated. The latter was collected on a filter, washed with alcohol and