The constituents of the flowers of Trifolium incarnatum / by Harold Rogerson.

  • Rogerson, Harold.
Date:
[1910]
Catalogue details

Licence: Attribution 4.0 International (CC BY 4.0)

Credit: The constituents of the flowers of Trifolium incarnatum / by Harold Rogerson. Source: Wellcome Collection.

Provider: This material has been provided by The Royal College of Surgeons of England. The original may be consulted at The Royal College of Surgeons of England.

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    195—196°. The aqueous acid liquid was treated with baryta for the removal of the sulphuric acid, filtered, and concentrated. It then yielded an osazone, which, after recrystallisation from dilute pyridine, melted at 203—205°. It is evident from the above results that the substance under examination was a glucoside of quercetin, and that its hydrolysis can be represented by the following equation : ^21^20^12 + H20 = C15Hj0O7 + C0H12Oc. Hitherto, only two other glucosides appear to have been isolated which give quercetin and glucose on hydrolysis, namely, osyritrin, C27H.2801G,3H20 (m. p. 185°), which was first obtained by A. G. Perkin from Cape sumach (Trans., 1897, 71, 1131), and quer- cimeritrin, C21H20O12,3H2O (m. p. 247—249°), which has quite recently been isolated by the same investigator from cotton flowers (Trans., 1909, 95, 2181). As there was a possibility of the above- described glucoside being identical with quercimeritrin, a specimen of the latter was kindly supplied by Professor A. G. Perkin for the purpose of comparison, but they were found to differ in their character. The glucoside obtained from Trifolium incarnatwm is therefore a new compound, and it is proposed to designate it incarnatrin, with reference to the specific name of the plant. Incarnatrin is hydrolysed by emulsin, and is therefore a /3-glucoside. It dissolves slowly in concentrated sulphuric acid with a yellow colour, and the solution soon develops a green fluorescence. The original aqueous liquid, after being freed from amyl alcohol by means of steam, was treated with an excess of a solution of basic lead acetate. A bulky, yellowish-brown precipitate was thus obtained, which was collected, well washed with water, then suspended in water, decomposed by hydrogen sulphide, and the mixture filtered. The resulting liquid, when concentrated, had a dark red colour, and appeared to contain only a small amount of tannic matter. The filtrate from the basic lead acetate precipitate was treated with hydrogen sulphide in order to remove lead, and concentrated under diminished pressure. A syrupy liquid was thus obtained which evidently contained a quantity of sugar, for it readily reduced Fehling’s solution, and yielded rZ-phenylglucosazone, melting at 205—206°. Examination of the Resin (B). This resin, as already indicated, represented that portion of the original alcoholic extract which was insoluble in water. At the ordinary temperature, it was a soft, green mass, and amounted to
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