The nature and origin of the poison of Lotus Arabicus / by Wyndham R. Dunstan and T.A. Henry.

  • Dunstan, Wyndham R. (Wyndham Rowland), 1861-1949.
Date:
1901
Catalogue details

Licence: In copyright

Credit: The nature and origin of the poison of Lotus Arabicus / by Wyndham R. Dunstan and T.A. Henry. Source: Wellcome Collection.

Provider: This material has been provided by The University of Glasgow Library. The original may be consulted at The University of Glasgow Library.

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    became well marked after 24 hours, whilst a and d showed no such effect. It is therefore proved that one of the enzymes of Lotus arabicus is able to decompose both salicin and amygdalin, though slowly. Action of Enzymes on Lotusin. A series of tubes containing each 5 cub. centims. of an aqueous solution of lotusin were made, and to these were added— a. 1 cub. centim. of sweet almond extract (emulsin). b. 1 cub. centim, of solution of malt extract (diastase). c. 1 cub. centim. of aqueous extract of yeast (invertase). d. 1 cub. centim. of aqueous extract of .Lotus. Only in tube d was there a rapid formation of hydrocyanic acid, but after 2 days it was also apparent in tube a. As the glucoside-destroying enzyme of Lotus is thus shown to be different from invertase, diastase, and also from emulsin, it is proposed to call it Lotase. Separation of the Enzymes of Lotus arabicus. Precipitation by Alcohol. A chloroform-water extract of the plant made as already described was poured into three times its volume of 90 per cent, alcohol. The voluminous white precipitate so formed was collected, re-dissolved in water, and re-precipitated in the same manner. It was then dried by exposure to the air on glass plates. It formed translucent scales, almost completely soluble in water. Its aqueous solution rapidly liquefied starch paste, and destroyed the coagulable albumen of Lathyrus sativus, but was incapable of hydrolysing either salicin or amygdalin. It appears, therefore, that lotase is rapidly destroyed by contact with alcohol. This proteid is also unstable in presence of glycerin. In both these respects lotase differs from emulsin. Precipitation on Calcium Phosphate. To a chloroform-water extract of the plant a few cub. centims. at a time of calcium- chloride solution and sodium-phosphate solution were successively added, the whole being well shaken after each addition of the two reagents. When a sufficient quantity of calcium phosphate had been formed the mixture was shaken for about an hour and filtered, the precipitate being drained by the filter-pump, and dried by exposure to the air on glass plates. The preparation so obtained was a white amorphous powder, which charred when heated in a test-tube. It exhibited both proteolytic and amylolytic power, and hydrolysed- both salicin and amygdalin. It consisted, therefore, of a mixture of the three enzymes present in this plant. 3 Y 2