The constituents of red clover flowers / by Frederick B. Power and Arthur H. Salway.

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

Licence: In copyright

Credit: The constituents of red clover flowers / by Frederick B. Power and Arthur H. Salway. Source: Wellcome Collection.

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    and citrullol, C22H3602(0H)2 (this vol., p. 102). These alcohols therefore appear to be members of a homologous series, which is represented by the general formula, CnH2TO_e04. Examination of the Fatty Acids. The ethereal solution, from which the above-described trifolianol had been removed by filtration, was washed, dried, and the solvent removed. The mixture of fatty acids thus obtained contained a considerable quantity of resinous material, which was insoluble in light petroleum, and was therefore removed by digesting the mixture with the latter solvent, and filtering. This resin was a dark green solid, amounting to 10 grams, but no definite crystalline compound could be isolated from it. The petroleum solution, on evaporation, yielded a dark-coloured mixture of fatty acids, which was distilled under diminished pressure. The pale yellow distillate, amounting to 60 grams, became partly solid on cooling. It was dissolved in alcohol, when a substance separated which, after several crystallisations from alcohol, melted at 60—61°: 0-1182 gave 0-3236 C02 and 0*1341 H20. 0 = 74*7; H = 12*6. 0*1280 required for neutralisation 5*02 c.c. iV/10-KOH. Neutralisation value = 220. C16H8202 requires 0 = 75-0; H = 12*5 per cent. Neutralisation value = 219*1. This substance was thus identified as palmitic acid. In order to ascertain the nature of the remaining constituents of the mixed fatty acids, the mother liquors from the above crystallisations were united, and, while hot, fractionally precipitated with a concentrated aqueous solution of barium acetate. The final precipitate was oily, and, as it consisted for the most part of the barium salts of unsaturated acids, it was separately examined as described below. From the other fractions of barium salt the fatty acids were regenerated, and, after one crystallisation from acetic acid, were titrated with a decinormal solution of potassium hydroxide. The neutralisation values of the several fractions were 199*0; 210*0; 213*0; 213*5; 214*8; and 216*9, whilst their melting points were 53—55°; 53—56°; 53—56°; 53—56°; 54—56°; and 56—59° respectively. These results indicated that the saturated acids consisted chiefly of a mixture of palmitic and stearic acids, the respective neutralisation values of which are 219*1 and 197*7. The acids obtained from the above-mentioned oily barium salt were converted into their lead salts, and the latter treated with ether. From the portion of lead salt which was undissolved by the ether, a further small amount of palmitic acid was obtained. The acids regenerated from the soluble lead salt formed a pale