Cyanogenesis in plants. Part IV .— The occurrence of phaseolunatin in common flax ( Linum usitatissimum )

In Part III of this series of paper it was shown that the seeds ofPhaseolus lunatus , as produced by the uncultivated plant in Mauritius, contained a new cyanogenetic glucoside, phaseolunatin, which was proved to have the constitution of a dextrose ether of acetonecyanhydrin. Phaseolunatin was further shown to undergo hydrolysis by mineral acids or by the action of the characteristic, emulsin-like enzyme also present in the seeds, yielding, as final products, acetone, hydrocyanic acid, and dextrose. This decomposition of the glucoside by the enzyme takes place when the ground seeds ofPhaseolus lunatus are mixed with water, and from such a preparation it is comparatively easy to isolate and identify the hydrolytic products, acetone, and hydrocyanic acid. The simultaneous production, therefore, of these two substances from plants by mere contact with water may be taken as indicating the occurrence in such plants of phaseolunatin or some similar derivative of acetonecyanhydrin, and of an enzyme capable of decomposing this compound under the condition specified.