— 13 — 



from 1 - mandelonitrile ; a third isomeride of mandelonitrile glucoside, 

 sambunigrin, possesses a still higher rotatory power than prulaurasin. 

 Prulaurasin is completely analogous to isoamygdalin ; it is a mixture 

 of two stereo -isomeric d- and l-mandelonitrile-/?-glucosides ; sambunigrin 

 must be the /?-glucoside of d-mandelic acid. 



If an aqueous solution of 1-mandelonitrile glucoside is treated with 

 a very small quantity of ammonia or 1/500-normal baryta water at 25°, 

 prulaurasin is formed. The prulaurasin obtained from Fischer's 

 glucoside melted at 123 to 125 . The individual glucosides differ from 

 each other by their readily obtainable acetyl derivatives. 



Amygdalin and isoamygdalin yield hepta-acetyl derivatives (m. p. 167 

 and 148 respectively), 1-mandelo-nitrile glucoside and prulaurasin yield 

 tetra-acetyl compounds (m. p. 136 and 120 to 123 respectively). 



When emulsin is allowed to act on amygdalin, there occurs after 

 some time, like with other enzyme reactions, a state of equilibrium; the 

 formation of hydrocyanic acid ceases, although the enzyme and also 

 amygdalin are still present. The explanation of this must be looked 

 for in the fact that the enzyme, at a definite concentration of its 

 decomposition-products, is no longer able to exert any action, or that 

 it is also capable of producing the reverse reaction. In the reaction 

 emulsin- amygdalin it is not definitely known whether both possibilities 

 come under consideration for bringing about this state of equilibrium. 

 Anyhow it is certain that the emulsin is not destroyed, as the reaction 

 continues if the benzaldehyde is removed by ether. During the distil- 

 lation, however, the reaction cannot proceed further, as the emulsin is 

 decomposed by the high temperature. But as amygdalin must still be 

 present, Rosenthaler 1 ) made the experiment of adding some sweet 

 almonds after cooling, and distilling afresh. On the first distillation, 

 which was only interrupted when the distillate gave no longer a hydro- 

 cyanic acid reaction, 0,215 an ^ °> 2 37% respectively were found; the 

 second distillate then still yielded 0,012 and 0,01 1 °/ hydrocyanic 

 acid respectively. If no sweet almonds were added, no further trace 

 of hydrocyanic acid passed over. 



Almond Oil, pressed, from almonds. The prospects of 

 the harvest in Puglia can on the whole be characterised as favourable, 

 so that, if nothing untoward occurs, a fall in the prices during the 

 present season may probably be reckoned upon. In the months of 

 May and June the quotations were driven up by speculators to 

 209 marks per 100 kilos (against 180 marks in October 1906), and 

 as this movement was supported by brisk enquiries from abroad, a 

 quieting down of the market was out of the question. The small 



x ) Sudd. Apotheker Ztg. 1907, 496, accord, to Apotheker Ztg. 22 (1907), 680. 



