Pfizer Handbook of Microbial Metabolites 444 



nucleotide base to fermentations. A review^^ lists about 

 50 such compounds, some of which have vitamin activity. 



There seems to be a fundamental similarity in the bio- 

 synthetic routes to vitamin B^o and the porphyrins. C^^- 

 Labeled glycine or 8-aminolevuhnic acid are heavily in- 

 corporated.-^'* Threonine furnishes the aminopropanol 

 moiety as demonstrated by incorporation of the amino 

 acid labeled with N^^^" There seems to be no information 

 yet on the biosynthetic origin of the dimethylbenzimida- 

 zole moiety. 



Red cobamide-containing polypeptides have been iso- 

 lated from microorganisms, and some of these can replace 

 cobamide in deficient microorganisms, and in the oral 

 treatment of pernicious anemia.*^' ^- 



Cobamides have been impUcated in several metabolic 

 processes.*^ In Escherichia coli mutants they seem to 

 assist in the formation and transfer of methionine methyl 

 groups" (folic acid is also required). They are thought 

 to be involved in the reduction of disulfides to thiols.*^ In 



38 D. Perlman, Advances in Appl. Microbiol. 1 87-112 (1952). (A 

 review) 



2^ David Shemin, John W. Corcoran, Charles Rosenblum and Ian 

 M. Miller, Science 124 272 (1956); John W. Corcoran and David 

 Shemin, Biochim. et Biophys. Acta 25 661 (1957). 



*° Alvin I. Krasna, Charles Rosenblum and David B. Sprinson, /. 

 Biol. Chem. 225 745 (1957). 



" H. G. Wijmenga, J. Lens and A. Middlebeek, Chem. Weekblad 45 

 342 (1949); H. G. Wijmenga and B. Hurenkamp, ibid. 47 217 (1951); 

 H. G. Wijmenga and W. L. C. Veer, ibid. 48 33 (1952); H. G. Wij- 

 menga, K. W. Thompson, K. G. Stern and D. J. O'Connell, Biochim. 

 et Biophys. Acta 13 144 (1954); H. G. Wijmenga, J. Lens and S. J. 

 Geerts, Acta Haematol. 11 372 (1954). 



i^K. Hausmann, Lancet 257 962 (1949); K. Hausmann and K. 

 MulU, Acta Haemotol. 1 345 (1952); idem.. Lancet 262 185 (1952); 

 K. Hausmann, Klin. Wochschr. 31 1017 (1953); K. Hausmann, L. 

 Ludwig and K. Mulli, Acta Haemotol. 10 282 (1953); K. Mulli and 

 O. J. Schmid, Z. Vitamin-, Hormon-u. Fermentforsch. 8 225 (1956); 

 J. G. Heathcote and F. S. Mooney, Lancet 274 982 (1958). 



43R. D. Wilhams (Ed.), "The Biochemistry of Vitamin B,..," June 

 Lascelles and M. J. Cross, The function of vitamin B,j in microorgan- 

 isms. Biochemical Society Symposia No. 13, Cambridge University 

 Press, London, 1955, pp. 109-123. 



•i^C. W. Helleiner and D. D. Woods, Biochem. J. 63 26p (1956). 



■•^ J. W. Dubnoff and E. Bartroy, Arch. Biochem. and Biophys. 62 

 86 (1956); Chiun T. Ling and Bacon F. Chow, J. Biol. Chem. 206 797 

 (1954). 



