Chemical examination of grindelia. Pt. 2 / by Frederick B. Power and Frank Tutin.

  • Frederick Belding Power
Date:
[1907?]
Catalogue details

Licence: In copyright

Credit: Chemical examination of grindelia. Pt. 2 / by Frederick B. Power and Frank Tutin. Source: Wellcome Collection.

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    and as this acid contains only one double linking, it may be assumed that a benzene nucleus is also present in its structure. In view of this con¬ sideration a quantity of the ester was oxidized by means of a chromic acid mixture, with the hope of isolating a known benzene derivative from the products, but only resins were obtained. The acid produced by the hydrolysis of fraction V was an extremely viscous liquid, and nothing crystalline could be obtained from it. Fraction VI was evidently similar to the preceding one, whilst the fractions of higher boiling-point, although obviously mixtures, would appear to contain esters of more highly oxy¬ genated acids. It is evident from a consideration of the iodine values of the above fractions of esters, together with the amount of hydrogen which they respectively contain, that cyclic compounds must be present in each of them. The original ethereal liquid, which, after extraction with sodium car¬ bonate, still contained the non-acidic constituents of the petroleum ex¬ tract, was shaken with a io per cent, solution of potassium hydroxide. This treatment removed nothing, but on washing the ethereal liquid with water, after separating the alkaline solution, a deep green, aqueous liquid was obtained. This evidently contained that portion of the chlorophyll which had been present in the petroleum extract. It was separated from the ethereal liquid, acidified with sulphuric acid, and extracted with ether, when, on removing the solvent, a quantity of a bright green, resinous substance was obtained. This product, which consisted of chlorophyll, evolved ammonia when boiled with alcoholic potash, and since none of the other constituents of the petroleum extract contained nitrogen, it must have been the source of the ammonia which, as noted in the previous communication {loc. cit.), was evolved in considerable amount on boiling the entire petroleum extract with the alcoholic alkali. The ethereal liquid, which now no longer contained any acidic or phenolic substances, was dried, and the ether removed. The residual fatty matter was dissolved in alcohol, and boiled for two hours with an excess of an alcoholic solution of potassium hydroxide. The alcohol was then removed, water added, and the resulting liquid repeatedly extracted with ether. During the first extraction a small quantity of a flocculent precipitate accumulated in the lower portion of the ethereal layer. This solid was collected on a filter, .well washed with w^arm ether, and dried. On examination it was found to be the potassium salt of a fatty acid, for, when treated with sulphuric acid, it afforded an acid which crystallized from ethyl acetate in leaflets melting at 84° C. This was analyzed with the following result : 0.1119 gave 0.3245 C02 and 0.1340 H20. C = 79.1; H = 13.3. C27H5402 requires C— 79.0; H = 13.2 per cent. This substance appears to be identical with the acid melting at 81-82° C.,
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