RIBOFLAVINK 



1. S. A. Schou and B. Fretheim, Dansk. Tidskr. Farm., 1940, 14, 97 ; 

 Merck & Co., B.P. 4966/47. 



3. R. Kuhn, Klin. Woch., 1938, 17, 222. 



4. A. E. Jurist, U.S. P. 2358331. 



5. D. V. Frost, /. Biol. Chem., 1942, 145, 693 ; U.S.P. 2388261. 

 5a. Wyeth Inc., U.S.P. 2445208. 



56. R. A. Harte and J. L. Chen, /. Amer. Pharm. Assoc. Sci. Ed., 



1949, 38, 568. 

 5c. American Cyanamid Co., U.S.P. 2449041 ; Wyeth Inc., U.S.P. 



2449640. 



6. Hoffmann-La Roche, B.P. 555346 ; U.S.P. 2349986, 2438880. 



7. Winthrop Chemical Co.. B.P. 560631 ; U.S.P. 2332548. 



8. EU Lilly & Co., U.S.P. 2395378. 



9. M. R. Zentner, U.S.P. 2423074. 



10. Merck & Co., U.S.P. 2358356 ; M. F. Furter, G. J. Haas and 



S. H. Rubin, /. Biol. Chem., 1945, 160, 293. 

 loa. American Cyanamid Co., U.S.P. 2449003. 

 106. K. Schoen and S. M. Gordon, Arch. Biochem., 1949, 22, 149. 



11. D. V. Frost, /. Amer. Chem. Soc, 1947, 69, 1064 '> U.S.P. 2407412. 



12. R. Kuhn and G. Moruzzi, Ber., 1934, 67, 888. 



13. B. Sure and Z. W. Ford, Proc. Soc. Exp. Biol. Med., 1943, 64, 83. 



14. R. R. Williams and V. H. Cheldelin, Science, 1942, 96, 22. 



15. W. J. Peterson, F. M. Haig and A. O. Shaw, /. Amer. Chem. Soc, 



1944, 66, 662. 



16. J. A. Ziegler, ibid., 1039. 



17. L. J. De Merre and W. S. Brown, Arch. Biochem., 1944, 5, 181. 



18. C. M. O'Malley and C. W. Sievert, Ind. Eng. Chem., 1942, 34, 11 17. 



19. D. V. Frost, /. Biol. Chem., 1942, 145, 693 ; Abbott Labs., U.S.P. 



2388261. 



7. ESTIMATION OF RIBOFLAVINE 

 Biological Assays 



Riboflavine is generally regarded as the component of the vitamin 

 B2 group responsible for increasing the growth rate of rats and chicks, 

 but it is not unique in this respect, and other factors contribute 

 materially to the growth of animals on a synthetic diet. Consequently 

 the problem of developing a good biological method of assay resolves 

 itself mainly into the problem of providing adequate amounts of the 

 other members of the group in the diet, without at the same time intro- 

 ducing small amounts of riboflavine. Care must also be taken to 

 prevent coprophagy, since riboflavine is synthesised by micro-organisms 

 present in the contents of the gut (see page 183). 



H. von Euler and M. Malmberg ^ and El Sadr et al.^ used rats, the 

 latter group of workers introducing the vitamin Bg group into the 

 diet in the form of an aqueous extract of whole liver from which the 



156 



