The chemistry of the bark of Robina pseud-acacia, Linné (false acacia or common locust) / by Frederick B. Power.

  • Power, Frederick B. (Frederick Belding), 1853-1927
Date:
[1901]
Catalogue details

Licence: In copyright

Credit: The chemistry of the bark of Robina pseud-acacia, Linné (false acacia or common locust) / by Frederick B. Power. Source: Wellcome Collection.

    11/30 (page 7)
    p. 361), in which it has been shown that certain classes of carbo¬ hydrates when acted upon at the ordinary temperature with dry hydrogen bromide in ethereal solution give an intense purple colour, and suggested that the rapid production of this colour was indicative of ketohexoses, or of substances which produce them by hydrolysis, it was thought of interest to try the action of this reagent upon the Robinia proteid. It has been noted, however, by Fenton in his most recent communication that the production only of a purple colour is not sufficiently conclusive, and that the observation should be confirmed by the actual isolation and identification of crystals of the respective compound w—bromo- methylfurfural, C6k502Br, or CH:C-CH.,Br l O CHiC-CHO. The method he has suggested as most suitable for quantitative purposes was therefore adopted in the following experiment. One gramme of the proteid and 12'5 C.c. of chloroform, which had been saturated at 0° C. with dry hydrogen bromide, were heated together in a sealed tube at the temperature of the water-bath for two hours. An insignificant purplish colour was produced on the surface of the tube around the substance, but even after standing for several hours, this colour was not imparted to the liquid, whilst the substance itself had become quite black. The chloroform solution was then treated successively with anhydrous sodium carbonate and a few drops of a strong solution of this salt, dried over calcium chloride, and1 finally allowed to evaporate in a weighed glass dish. A very slight residue was obtained, which contained no crystals, from which it may be inferred that a ketohexose grouping of the carbohydrate complex does not exist in the proteid molecule. In order to ascertain whether the Robinia proteid, or any sub¬ stance associated with it, is capable of acting as an enzyme or ferment the following experiments were made, which have been attended with interesting results. To an aqueous solution of amvgdalin, contained in a test tube, a small amount of the dry, precipitated proteid was added, the mixture well shaken, and the tube corked and set aside. After standing for a short time at the ordinary summer temperature a strong odour of bitter almond oil was developed, and the filtered liquid gave an abundant reaction for hydrocyanic acid. The amvgdalin had thus been split up in the same manner as bv emulsin, and it may be noted that this decomposition had pre¬ viously been observed to be effected by the ferment (myrosin)