14 THE BIOCHEMISTRY OF B VITAMINS 



ence point. Concentration may have to be carried up to a millionfold or 

 more before the substance is pure. In view of these facts it apears unde- 

 sirable to refer to a "vitamin concentrate" or to a vitamin having been 

 obtained "in concentrated form" unless its concentration has been carried 

 to a point at least 100 times that of a rich natural source. In the literature 

 in the past numerous "concentrates" have been so designated when they 

 were not substantially more active than crude extracts of liver or yeast. 

 In the writer's own experience, the difference between having a "concen- 

 trate" which is a crude extract and one which is several thousand times 

 as active as the starting material may involve the expenditure of many 

 thousands of man-hours of effort. To designate all such products "con- 

 centrates" regardless of how far the process has been carried shows a 

 lack of proper discrimination. 



Anti-Pernicious Anemia Principle (Vitamin Bio)- Of the vitamins 

 which have not as yet been completely characterized chemically, by far 

 the most interesting one at the present writing is the anti-pernicious 

 anemia principle which has been isolated approximately simultaneously 

 in crystalline form both in England 26 and in the United States. 27 



It is a red crystalline substance which does not melt before decomposi- 

 tion ; it contains cobalt, phosphorus and nitrogen, and is reported to have 

 a molecular weight of about 1500. It is active in clinical pernicious anemia 

 in doses of about 1 /xg per day, and is thought to be identical with the 

 "animal protein factor" 28 as well as the "cow manure factor" 29 which have 

 been reported to be required by chickens. 



The physiological activity of the substance as judged by its effect on 

 human subjects is much greater, weight for weight, than that of any of 

 the vitamins discussed. Its purification from liver represents several 

 millionfold concentration. 



The effectiveness of this principle in extremely small doses suggests its 

 catalytic functioning, which has been studied by inhibition analysis 

 (p. 475). Its relationship to normal nutrition is not entirely clear, but 

 the requirement of chickens and its relationship to macrocytic anemias of 

 nutritional origin make its status as a vitamin relatively secure. While 

 its universal presence in living cells has not been explored, it appears to 

 be widely distributed in nature and to be produced by various bacteria 

 and molds. 30 



It is interesting and significant to note that, although numerous labora- 

 tories have engaged in studying and attempting to concentrate the anti- 

 pernicious anemia principle, in terms of chronology no outstanding prog- 

 ress was reported until after the development of a microbiological test. 

 Actually, workers in England, however, appear to have used the red color 

 obtained chromatographically as a basis for clinical testing. This vitamin 



