Chemical examination of the roots of Phaseolus multiflorus / by Frederick B. Power and Arthur H. Salway.

  • Power, Frederick B. (Frederick Belding), 1853-1927.
Date:
[1913]
Catalogue details

Licence: In copyright

Credit: Chemical examination of the roots of Phaseolus multiflorus / by Frederick B. Power and Arthur H. Salway. 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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    lirst tested fur the presence of an alkaloid, but with a negative result. Separation op an Enzyme. A quantity (160 grammes) of the ground material was macerated with water at the ordinary temperature for about forty- eight hours, and the mixture then filtered under pressure. To the clear, filtered liquid twice its volume of alcohol was added when an abundant, flocculent precipitate was produced. This was collected, washed with a little alcohol, and dried in a vacuum desiccator over sulphuric acid, after which it could be reduced to a brown powder. It then amounted to 3-2 grammes, or 2 per cent, of the weight of the root. The substance gave the biuret reaction, and readily hydrolysed amygdalin, thus proving its enzymic activity. Inasmuch as no trace of hydrogen cyanide could be detected during the above-described maceration of the root with water, it may be concluded that no cyanogenetic glucoside was present. Extraction of the Root with Alcohol, and Distillation of the Extract with Steam. For the purpose of a general examination of the constituents of the root, 2 kilogrammes of the ground, air-dried material were completely extracted in a large Soxhlet apparatus with hot alcohol. After the removal of the alcohol a dark coloured, viscid extract was obtained, which amounted to 280 grammes. The greater portion (265 grammes) of this extract was mixed with water, and distilled in a current of steam. On extracting the dis- tillate with ether, and removing the solvent, about 0'2 gramme of a brown, limpid essential oil was obtained, which, unlike many of the products obtained in a similar manner, gave no reaction for furfuraldehyde. After the above-described operation there remained in the distillation flask a reddish-brown, aqueous liquid (A), together with a quantity of resinous material (B). The latter was separated by filtration, and well washed with water, the wash- ings being added to the main portion of the aqueous liquid. Examination of the Aqueous Liquid (A). Isolation of Furan-/3-monocarboxylic Acid, C5H403. The aqueous liquid was repeatedly extracted with ether, the ethereal extracts united, washed with a little water, dried, and the solvent removed, when about 1 gramme of a brown, oily product was obtained. This was redissolved in ether, the ethereal solution shaken with aqueous ammonium carbonate, and the alkaline liquid then acidified and extracted with ether. This ethereal liquid was dried and evaporated, when a residue was obtained which slowly crystallised. The crystals were drained on a porous tile, and then dissolved in a litt'e hot water, wheD, on cooling, glistening colourless leaflets were deposited, which melted at 120°, and gave no colouration with ferric chloride. A small portion of this acidic substance was esterified by heating with methyl alcohol and concentrated sulphuric acid, when an odour resembling that of methyl benzoate was produced. The crystalline substance did not con- sist, however, of benzoic acid, since when mixed with the lattef *