Fischer found that the enzyme "invertase," which is present in yeast, attacks methyl-d-glucoside but not methyl-l-glucoside.
The enzymes which act upon glucosides are many; the best known are emul sin and myrosin, which split up respectively amygdalin, the special glucoside of certain plants of the Rosaceae; and sinfgrin, which has a wide distribution among those of the Cruciferae.
It appears to be synthesized in the plant tissues from carbon dioxide and water, formaldehyde being an intermediate product; or it may be a hydrolytic product of a glucoside or of a polysaccharose, such as cane sugar, starch, cellulose, &c. In the plant it is freely converted into more complex sugars, poly-saccharoses and also proteids.
It is found in the volatile oils of Spiraea, and can be obtained by the oxidation of the glucoside salicin, (C13H1807), which is found in willow bark.
It can be synthetically prepared by the reduction of coniferyl alcohol, (HO) (CH 3 O) C6H3 CH :CH CH20H, which occurs in combination with glucose in the glucoside coniferin, C16H2208.
Soc., 1903, 85, 1305), who showed that cane sugar and maltose were a-glucosides, and raffinose an a-glucoside of melibiose.
A continuation of their work on bitter almond oil by Liebig and Wohler, who remained firm friends for the rest of their lives, resulted in the elucidation of the mode of formation of that substance and in the discovery of the ferment emulsin as well as the recognition of the first glucoside, amygdalin, while another and not less important and far-reaching inquiry in 'which they collaborated was that on uric acid, published in 1837.
A valuable medicinal glucoside named salicin (q.v.) is also extracted from the bark.
It occurs naturally in the form of the glucoside amygdalin (C20H27N011), which is present in bitter almonds, cherries, peaches and the leaves of the cherry laurel; and is obtained from this substance by hydrolysis with dilute acids: C20H27N011+2H20 =HCN+2C6H,206+C6H5CHO.
C6h2(Oh)2[I.2], C]] a vegetable dyestuff formerly prepared from madder root (Rubia tinctorum) which contains a glucoside ruberythric acid (C26H28014).
This glucoside is readily hydrolysed by acids or ferments,breaking up into alizarin and glucose: 214 O Ruberythric acid = Glucose+Alizarin.
Its properties are due to the presence of a glucoside known as Morindin, which is compounded from glucose and probably a trioxy-methyl-anthraquinone.
Other ingredients are a fixed oil, present to the extent of 30%, ergotinic acid, a glucoside, trimethylamine, which gives the drug its unpleasant odour, and sphacelinic acid, a non-nitrogenous resinoid body.
Friedrich Rochleder has described as constituent principles of the cotyledons aphrodaescin, C52H82023, a bitter glucoside, argyraescin, C27 H 42012, aescinic acid, C21H40012, and queraescitrin, C41 H 46025, found also in the leaves.
As a free alkaloid) in the plant, but that it exists in the form of a glucoside, and that by the process of chewing this glucoside is split up by one of the ferments in the saliva into the free alkaloid and sugar.