VITAMIN Bjo (ERYTHROTIN) 



References to Section i 



1. G. R. Minot and W. P. Murphy, /. Amer. Med. Assoc, 1926, 87, 



470. 



2. E. L. Smith, Nature, 1948, 161, 638. 



3. E. L. Rickes, N. G. Brink, F. R. Koniuszy, T. R. Wood and K. 



Folkers, Science, 1948, 107, 396 ; 1948, 108, 135. 



4. W. B. Emery and L. F. J. Parker, Biochem. J. Proc, 1946, 40, iv. 



5. M. S. Shorb, Science, 1948, 107, 397. 



6. R. West, ibid., 398. 



7. E. L. Smith, Nature, 1948, 162, 144. 



8. B. ElUs, V. Petrow and G. F. Snook, /. Pharm. Pharmacol., 1949, 



1, 60, 287. 



9. N. G. Brink, D. E. Wolf, E. Kaczka, E. L. Rickes, F. R. Koniuszy, 



T. R. Wood and K. Folkers, /. Amer. Chem. Soc, 1949, 71, 1854. 



10. E. Kaczka, D. E. Wolf and K. Folkers, ibid., 1514. 



11. J. V. Pierce, A. C. Page, E. L. R. Stokstad and T. H. Jukes, ibid., 



2952. 



12. E. L. Rickes, N. G. Brink, F. R. Koniuszy, T. R. Wood and K. 



Folkers, Science, 1948, 108, 634. 



13. K. Hausmann, Lancet, 1949, 2, 962. 



2. ISOLATION, PURIFICATION AND PROPERTIES OF 

 VITAMIN B12 



Isolation and Purification 



Vitamin B^g was prepared from either liver extract or a culture of 

 S. griseus by chromatographic adsorption on activated alumina or 

 charcoal.^ The former was eluted with methanol or aqueous methanol 

 and the latter with an aqueous solution of acetone, butanol or benzyl 

 alcohol. In either instance, the eluate was evaporated, and the 

 residue dissolved in alcohol. After filtration the solution was evap- 

 orated and the residue dissolved in methanol. Vitamin B^g was pre- 

 cipitated from this solution by the addition of acetone or ether, the 

 precipitate was dissolved in water and the solution treated with 

 acetone. The resulting precipitate was dissolved in methanol and 

 several voliunes of acetone were added to precipitate the vitamin, 

 which was then dissolved in water and acetone added until a turbidity 

 formed. On standing, red crystals of vitamin B^g separated out. 



Concentrates of vitamin B^g were also purified prior to crystallisa- 

 tion by counter-current distribution between water and a mixture 

 (3 : i) of toluene and o-cresol. 



Partition chromatography has also been used to purify vitamin 

 Bi2- Strips of filter paper developed with wet w-butanol were used 

 preparatory to microbiological assay ^ (page 534), whilst columns of 



532 



