SYNTHETICAL PROPERTIES OF EMULSIN 



VERNON K. KRIEBLE 

 (Chemical Laboratory, McGill University, Montreal, Canada) 



In a recent communication^ the writer described an emulsin 

 which produced Isevo-mandelonitrile when allowed to act for three 

 and one-half hours on an amygdalin Solution. Those experiments 

 were conducted during the spring of 1910. Much to our surprise 

 when the research was continued in October, 1912, it was found 

 that, under the conditions previously described, the nitrile produced 

 was dextro active. This seems to explain the fact that the author's 

 results differed from those of Feist, Rosenthaler, and Auld, who 

 found dextro-nitrile. Their samples "of emulsin were evidently 

 much older than the one used by the author for his first determina- 

 tions. 



It seems very probable that there are two synthetic enzymes in 

 a fresh sample of emulsin, one of which synthesizes dextro-mandelo- 

 nitrile from benzaldehyde and hydrocyanic acid, while the other 

 synthesizes a Isevo-nitrile. The one synthesizing the dextro-nitrile 

 is evidently more stable. 



Fresh emulsin was extracted from bitter and from sweet 

 almonds. It was found that the sample from sweet almonds, 

 when allowed to act on amygdalin for three and one-half hours, 

 produced Isevo-nitrile while the one from the bitter almonds was 

 dextro active. 



The detailed experimental results will appear very shortly in 

 one of the chemical Journals. 



^Krieble: Journal of the American Chemical Society, 1912, xxxiv, p. 716. 



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