ISOLATION, PURIFICATION AND PROPERTIES 



starch developed with a mixture (i : 2 : i) of o-i N-hydrochloric acid, 

 w-propanol and w-butanol were claimed^ to effect a high degree of 

 purification. 



Properties 



Vitamin Bjg forms red needle-like birefringent crystals with no 



definite melting-point, but they darken at about 210° to 220° C. It 



is soluble in water, methanol, ethanol and phenol, but substantially 



insoluble in acetone, ether and chloroform. In aqueous solution it 



gives a characteristic absorption spectrum with maxima at 278, 361 



I *y 

 and 550 m/x. ; the values of E^^^ at these wave-lengths were 119, 



187 and 59 respectively.^ An aqueous solution of vitamin B^gj gave 

 an absorption spectrum with maxima at 273, 351 and 525 m/Lt.^ 



Analysis of vitamin B^g indicated a formula approximating to 

 C6i_64 H86-92 '^u ^13 ^^o and a molecular weight of about 1490. 

 Vitamin B^g is /-rotatory, and hydrolysis did not liberate a-amino acids. 



Chemical Constitution 



The chemical constitution of vitamin B^^ is not yet known, but 

 degradation experiments have revealed the structure of certain parts 

 of the molecule. Alkaline fusion yielded substances which reacted 

 in the same way as pyrroles with ^-dimethylaminobenzaldehyde,^ and 

 acid hydrolysis gave 5 : 6-dimethylbenzimidazole, the structure of 

 which was confirmed by synthesis.^ Thus the molecules of vitamin 

 B12 and riboflavine contain the same nucleus. Acid hydrolysis also 

 liberated ammonia and a ninhydrin-reacting substance, which appeared 

 to be 2-aminopropanol.'^ 



References to Section 2 



1. Merck & Co., S. African Pat. 7724. 



2. W. F. J. Cuthbertson and E. L. Smith, Biochem. J. Proc, 1949. 



44, V ; 1949, 45, xii ; G. E. Shaw, ibid., 1949. 44, liv ; W. A. 

 Winsten and E. Eigen, /. Biol. Chem., 1949, 181, 109. 



3. H. Borsook, C. L. Deasy, A. J. Haagen-Smit, G. Keighley and 



P. H. Lowy, Science, 1949, 110, 528. 



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



Amer. Chem. Soc, 1949, 71, 2952. 



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



T. R. Wood and K. Folkers, ibid., 1854. 



6. N. G. Brink and K. Folkers, ibid., 2951 ; E. R. HoUiday and 



V. Petrow, /. Pharm. Pharmacol., 1949, 1» 734 ; G- R- Beaven, 

 E. R. Holliday, E. A. Johnson, B. Ellis, P. Mamalis, V. Petrow 

 and B. Sturgeon, ibid., 957. 



7. B. ElUs, V. Petrow and G. F. Snook, ibid., 735, 950. 



533 



