The synthetical preparation of the d-glucosides of sitosterol, cholesterol, and some fatty alcohols / by Arthur H. Salway.
- Salway, Arthur H. (Arthur Henry)
- Date:
- [1913?]
Licence: Public Domain Mark
Credit: The synthetical preparation of the d-glucosides of sitosterol, cholesterol, and some fatty alcohols / by Arthur H. Salway. Source: Wellcome Collection.
5/12 page 1024
![The formation of two modifications of ceryl-d-glucoside, C27H550*CGHll05, is of some interest in connexion with an observation of E. Fischer and Helferich {Joe. cit.) regarding the properties of cetyl-^-glucoside, C16H3g0*C6Hn05. These investi¬ gators showed that cetyl-<7-glucoside melts indefinitely, beginning to change at 78° and finally melting at about 145°; it now seems probable, in view of the results obtained with ceryl-^-glucoside, that this behaviour is due to the presence of two modifications. In order to ascertain whether this were the case, cetyl-d7-glucoside was pre¬ pared, but although it was found to possess the properties described by Fischer and Helferich, it was not possible to separate the two modifications. Experimental. I. Sitosterol-d-glucoside, C27H4rJ0*CGH110fj. The sitosterol required for the preparation of this compound was obtained from wheat-germ (compare Burian, Monatsh., 1897, 18, 551). The fatty oil from 50'8 kilos, of the latter was hydrolysed with an excess of potassium hydroxide in the presence of alcohol, and the resulting soap solution extracted repeatedly with ether. The ethereal solution was then evaporated, and the residue crystallised from ethyl acetate, when the sitosterol was obtained in colourless needles, melting at 138°. The amount of pure substance isolated from 50'8 kilos, of wheat germ was 130 grams (compare Pickard, T., 1908, 93, 1928). It possessed the specific rotation [a]D —32*2° (c = 2’9 with chloroform), and on analysis gave results agreeing well with the formula C27H460. In order to ascertain whether the material was quite free from stigmasterol, it was acetylated, and the acetyl derivative treated with bromine according to Windaus and Hauth’s method (Ber., 1906, 39, 4378), but a negative result was obtained, thus showing the absence of stigmasterol. For the conversion of sitosterol into its glucoside, 15 grams of anhydrous substance and 15 grams of pure bromoacetoglucose were dissolved in dry ether and shaken continuously for eight hours with freshly precipitated, dry silver oxide. The mixture was then filtered, a little dilute nitric acid having been previously added to coagulate the silver oxide and facilitate the filtration, after which the ethereal filtrate was washed, dried, and evaporated. The residue was next crystallised once from alcohol to remove a small amount of soluble by-product formed from the bromoacetoglucose. The substance thus obtained then consisted of a mixture of tetra-acetyl- sitosterol-d-glucoside and unchanged sitosterol, and could not be resolved into its components by direct fractional crystallisation. It](https://iiif.wellcomecollection.org/image/b30620375_0005.jp2/full/800%2C/0/default.jpg)
