422 Scientific Proceedings (132) 



207 (2167) 



The presence of a blood-sugar reducing substance in yeast. 

 By CASIMIR FUNK and H. B. CORBITT. 



[From the Research Laboratory of H. A. Metz, New York City.] 



In 1914 one of the present authors reported in collaboration 

 with v. Schoenborn 1 that pigeons kept on a vitamine-free, ar- 

 tificially compounded diet, show complete disappearance of 

 the glycogen in the liver and increased blood sugar. In one 

 particular series of experiments the blood sugar amounted 

 to 0.29 per cent, and no glycogen was found in the liver. In a 

 few pigeons kept on the same diet one dose of vitamine B from 

 yeast was injected intramuscularly with the result that liver was 

 found to contain 0.6 per cent, of glycogen and the blood 0.19 per 

 cent, sugar. This vitamine preparation, which proved to be 

 very potent, was prepared in the following way : an evapo- 

 rated alcoholic extract of yeast was precipitated with phospho- 

 tungstic acid, and the resulting dried precipitate treated with ace- 

 tone. The insoluble fraction was decomposed with lead acetate 

 and the filtrate freed from adenine by means of picric acid. 



This observation gains much interest in view of the recent 

 communications of Winter and Smith and also of Collip on the 

 presence of an insulin-like substance in yeast and other starting 

 materials. 



For some time past we have been working on the same problem 

 again. We have found that crude extracts of yeast and rice- 

 polishings possess a blood-sugar increasing rather than decreas- 

 ing action. When we took, however, yeast grown in the labora- 

 tory on a medium rich in vitamine D, then centrifuged and 

 washed the cells, and after heating to 100° injected them subcu- 

 taneously into rabbits, we obtained in a number of instances in 

 3-4 hours blood-sugar decreases which amounted to 30-40 per 

 cent, of the initial value. We agree with Collip that compared 

 with insulin the action of the yeast substance is slow, but on the 

 other hand it lasts longer which might prove of therapeutic ad- 



1 J. Physiol., 1914, cccxxviii, 48. 



