The Vit amines of .Yeast. 



i5 



7 (i754) 



The vitamines of yeast and their role in animal nutrition. 



By CASIMIR FUNK and HARRY E. DUBIN. 



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



The question whether pigeons and rats require for their well- 

 being the same vitamine B has been discussed at length by Mitchell 

 and Emmett a few years ago with the conclusion that vitamine B 

 must be different from the antineuritic substance. Funk and 

 Macallum have tested the phosphotungstate precipitate obtained 

 from yeast and have found that while it was strongly curative for 

 avian beriberi, it induced only moderate growth in rats. The 

 present writers were able to show recently that by fractional ad- 

 sorption with fuller's earth or norit it is possible in most cases to 

 effect an almost quantitative separation of the B-vitamine, cura- 

 tive for avian beriberi from another substance, which we pro- 

 visionally have called vitamine D and which acts on yeast and 

 certain bacteria. In practice the separation is effected as follows : 

 One liter of autolyzed yeast is shaken with 50 g. of fuller's 

 earth; the filtrate which in the majority of cases was found in- 

 active for avian beriberi was treated twice with the double amount 

 of fuller's earth, the combined precipitates carrying down quantita- 

 tively the vitamine D, the last filtrate being devoid of the two 

 above-mentioned substances. 



Having succeeded in this separation (the procedure varying 

 somewhat with different samples of autolyzed yeast) we thought 

 it worth while to test out the fractions obtained on animals, 

 making simultanous tests on pigeons, rats, yeast and streptococci. 

 The experiments carried out with six rats and four pigeons in 

 every case will be repeated and extended and the present com- 

 munication is only of a preliminary character. While the pigeons 

 were found to need only the vitamine B when fed on a vitamine-free 

 diet, the rats exhibited a somewhat different behavior. They 

 were fed the usual so-called synthetic diet with cod liver oil as 

 source of vitamine A. The rats receiving the vitamine B or D 

 fraction as an addition grew only for a few weeks at a slow rate 

 and started to die out after two months. While increasing 



