Pfizer Handbook o£ Microbial Metabolites 



482 



chemistry of microbiological reactions with emphasis on 

 those promoted by dehydrogenases. ° 



The biosynthesis of nicotinic acid has been studied in 

 several different biological systems. In neurospora (and 

 in mammals) tryptophan is the source with 3-oxyanthra- 

 nilic acid a proved intermediate.^" "• ^^' " ^*' ^^ The re- 

 maining stages of this route are obscure, although a- 

 aminomethyl-a,/i^-trarzs-y,8-cis-muconic acid may be an in- 

 termediate.^'^ It has been shown to be a precursor of 

 nicotinic acid for the bacterium Xanthomonas pruni. If 

 it proves to be generally significant, then the following 

 scheme can be written: 



O NH2 



CH, 



-CH— COOH 

 NHo — 



~7^ 



o, 



Tryptophan 



NH2 



C— CH,— CH— COOH 



CHO 

 ^NH-^^ 

 N-Formylkynurenine 



NH2 



CO: 

 [O] 



CO— CH,— CH— COOH 



NHo 



Kynurenine 



CO— CHj— CH— COOH 



NH. 



3- Hydroxy kynurenine 



»G. E. W. Wolstenholme and Cecilia M. O'Connor (Eds.), CIBA 

 Foundation Study Group No. 2, "Sterlc Course of Microbiologi- 

 cal Reactions," Little, Brown and Company, Boston, 1959, 115 pp. 



" W. A. Krehl, L. J. Teply, P. S. Sarma and C. A. Elvehjem, Science 

 101 489 (1945). 



" Fred Rosen, Jesse W. Huff and William A. Perlzweig, /. Biol. 

 Chem. 163 343 (1946). 



'- G. S. Beadle, H. K. Mitchell and J. F. Nye, Proc. Nat. Acad. Sci. 

 33 155 (1947). 



'^ Francis A. Raskins and Herschel K. Mitchell, ibid. 35 500 

 (1949). 



1* Irving L. Miller and Edward A. Adelberg, /. Biol. Chem. 205 691 

 (1953). 



I'^WiUiam B. Jakoby and David M. Bonner, ibid. 205 699, 709 

 (1953). 



"J. O. Harris and F. Binns, Nature 179 475 (1957). 



