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.

    11/28 (page 239)
    0-1750 gave acetic acid equivalent to 12*5 c.c. iV710-Ba(OH)2 CO-CH3 = 30-7. The molecular weight of the acetyl derivative was also ascertained by the ebullioscopic method : 0-1768, in 26’46 of benzene, gave M 0-043°. M.W.=415. ci5H70g(CO-CH3)3 requires COCH3 = 31*3 per cent. M.W.=412. The substance, 0 j5H1(jOg, is soluble in alkali hydroxides, forming a colourless solution. In alcoholic solution it gives with ferric chloride a dark green coloration. With concentrated sulphuric acid, only a faint yellow colour is produced. The yield of the substance C15H10OG was very small, not more than 0 5 gram having been obtained from 37*1 kilograms of dried clover flowers. Isolation of a New Glucoside, Trifolin, C22H220n,H20. The oiiginal aqueous liquid (A), which had been extracted with ether, as already described, was kept for a considerable time, when it was observed that a quantity (about 60 grams) of a light brown solid had been deposited. This was collected, and purified by repeated crystallisation from aqueous pyridine, when it separated in minute, slender, pale yellow needles, melting and decomposing at about 260°. The substance contained water of crystallisation, which was lost at 115°, but was again absorbed on exposing the anhydrous substance to the air: 0-3051, on heating at 115°, lost 0*0130 H20. IL>0 = 4-3. 0-1101 * gave 0-2302 C02 and 0*0464 H2Cb C = 57*0; H = 47. 0-1194* „ 0-2481 C02 „ 0*0506 H.O. C = 56*7; H = 4'7 0-1010* „ 0-2115 C02 „ 0-0440 H20. 0 = 57*1; H = 4*8. C22H220n,H20 requires H20 = 37 per cent. C22H22°h requires C = 57*l; H = 4’8 per cent. These results indicated the formula of the above-described sub¬ stance to be C22H22On, and it proved to be a glucoside. As it is a new compound, it is proposed to designate it trifolin, with reference to the generic name of the plant from which it was obtained. Tiifolin, C22H220n,H20, is insoluble in chloroform, benzene, or cold water. It is not readily dissolved by alcohol, but is very soluble in pyridine and is best crystallised from a mixture of the latter solvent with water. With aqueous sodium carbonate and the alkali hydroxides, it gives intensely yellow solutions. It dis¬ solves in concentrated sulphuric acid, forming at first a yellow solution, but which rapidly develops a brilliant green fluorescence. In alcoholic solution it gives with ferric chloride a dark brown coloration. No crystalline acetyl derivative of trifolin could be prepared. Anhydrous substance.