The simple carbohydrates and the glucosides / by E. Frankland Armstrong.
- Edward Frankland Armstrong
- Date:
- 1910
Licence: In copyright
Credit: The simple carbohydrates and the glucosides / by E. Frankland Armstrong. Source: Wellcome Collection.
101/132 page 85
![TABLE XIV. M.-p. [«]•>. Amygdonitrile glucoside = laevo mandelonitrile glucoside Prulaurasin = racemic mandelonitrile glucoside Sambunigrin = dextro mandelonitrile glucoside 147-150° 120-122° I5I-I520 - 26-9° -527° - 76-3° Dunstan and Henry suggested that the differences between these lay in the nature of the sugar residue. This can hardly be the case, as they are all three attacked by emulsin, and therefore derivatives of /3-glucose. Prulaurasin is, in fact, a racemic mixture of the two stereoisomeric d- and /-mandelonitrile /3-glucosides, and analogous to isoamygdalin, the racemic form of amygdalin, first prepared by the action of alkali on amygdalin by Walker and subsequently studied by Dakin, which yields inactive mandelic acid when hydrolysed by acids; indeed, prulaurasin is obtained by acting on isoamygdalin with yeast extract—amygdalase (Herissey). Sambunigrin is the /3-glucoside of ^/-mandelonitrile glu- coside, and derived from a still unknown isomeride of amygdalin. Prulaurasin is obtained from either of the other two isomerides, when their aqueous solutions are rendered slightly alkaline. The true relationship of these glucosides was first established by Caldwell and Courtauld, and their conclusions have been entirely con- firmed by Bourquelot and Herissey. More recently amygdonitrile glucoside has been discovered as a natural product, so that all three isomerides must play some part in plant economy. Herissey found it in the young branches of Cerasus Padus; Power and Moore have obtained it from wild cherry bark (Prunus serotind). The inter-relationship of these compounds is indicated in the ac- companying scheme. Possibly the unknown isomeride of amygdalin will also be found in the plant:— Amygdalin Isoamygdalin Unknown Amyg dalase Amygdonitrile glucoside = 1-mandelonitrile glucoside Amyg dalase Prulaurasin = rfl-mandelonitrile glucoside Sambunigrin = rf-mandelonitrile glucoside](https://iiif.wellcomecollection.org/image/b28062954_0101.jp2/full/800%2C/0/default.jpg)
