The constituents of leptandra / by Frederick B. Power and Harold Rogerson.

  • Frederick Belding Power
Date:
[1910?]
Catalogue details

Licence: In copyright

Credit: The constituents of leptandra / by Frederick B. Power and Harold Rogerson. Source: Wellcome Collection.

    11/18 (page 1952)
    dried, and distilled under diminished pressure, when they passed over between 220° and 250°/15 mm. as a pale yellow oil. The acids thus obtained, which amounted to 4*2 grams, were mixed with the previously mentioned portion of acids present in the free state, and the whole converted into their lead salts, the latter being then digested with ether, when a portion was dissolved. Both the soluble and insoluble portions were decomposed by hydrochloric acid, and the regenerated fatty acids purified by distillation under diminished pressure. The soluble portion of the lead salts yielded 4*2 grams of liquid acids, whilst the insoluble portion gave 3*3 grams of solid acids. The Liquid Acids.—These acids, when distilled under diminished pressure, passed over between 215° and 235°/15 mm. as a yellow oil. An analysis and a determination of the constants gave the following results: 0*1738 gave 0*4842 C02 and 0*1788 H20. C = 76*0; H = ll*4. 0*3788 absorbed 0*4872 iodine. Iodine value—128*6. 0*1540 neutralised 0*0307 KOH. Neutralisation value = 199*3. C]SII3.jOo requires C = 76*6; H = 12*l per cent. Iodine value = 90*1; Neutralisation value = 198*9. C]8H3202 requires C = 77*l; H = ll*4 percent. Iodine value = 181*4 ; Neutralisation value = 200*4. It is evident from the above results that the liquid acids con¬ sisted of a mixture of oleic and linolic acids. The Solid Acids.—These acids, after being again distilled under diminished pressure, were crystallised twice from ethyl acetate, when they melted at 54—56° : 0*1512 gave 0*4190 C02 and 0*1728 H20. C = 75*6; H = 12*7. 0*2864 neutralised 0*0590 KOH. Neutralisation value = 206. C16H3202 requires C = 75*0; H = 12*5 per cent. Neutralisation value = 219*1. C1sH3602 requires C = 76*l; H = 12*7 per cent. Neutralisation value = 197*5. These results indicate that the solid acids consisted of a mixture of palmitic and stearic acids in about equal proportions. Ethereal Extract of the Resin. During the extraction of the resin with ether a quantity of a sparingly soluble, yellowish-brown substance was deposited, and when the extraction was complete this was collected, washed with ether, and dried, when it was found to weigh 5 grams. It was entirely amorphous, and proved to be similar in character to the product extracted from the original aqueous liquid by amyl alcohol,