Pfizer Handbook of Microbial Metabolites i8 



These reactions in summary are: 



6 Hexose phosphate + 60.- — > 6 Pentose phosphate + 6CO> + 6H2O 

 4 Pentose phosphate — > 2 Hexose phosphate + 2 Tetrose phosphate 

 2 Pentose phosphate + 2 Tetrose phosphate — > 



2 Hexose phosphate + 2 Triose phosphate 

 2 Triose phosphate + H2O — > Hexose phosphate + phosphate 



Hexose phosphate + 6O2 — > 6CO.; + 5H2O + phosphate 



This is, then, a route for the complete degradation of glucose 

 to carbon dioxide and water. The statistical significance and 

 prevalence of this oxidative degradation system among micro- 

 organisms remains to be determined. 



Ribose can be synthesized by way of the pentose phosphate 

 cycle. In B. coli it appears that deoxyribose arises from direct 

 reduction of ribose.® 



Gluconic acid occurs widely, especially in fungi, and can be 

 formed by enzyme-catalyzed oxidation of the unphosphorylated 

 glucose substrate.'* In some oxidative bacteria the following 

 scheme occurs:^" 



Glucose — > Gluconic Acid — > 6-Phosphogluconic Acid — > 



2-Keto-3-deoxy-6-phosphogluconic Acid -^ Pyruvic Acid 



+ 

 Glyceraidehyde-3-phosphate 



The glyceraldehyde phosphate is easily convertible to another 

 mole of pyruvic acid. 



Both glucuronic acid" and fucose (6-deoxy-L-galactose)^'- 

 seem to be formed from glucose without cleavage of the carbon 

 skeleton. 



Glucosamine is probably most commonly formed by gluta- 

 mine amination of fructose-6-phosphate,^'^ although glucosone 



^ Fillmore K. Bagatell, Elmer M. Wright and Henry Z. Sable, 

 ;. Biol. Chem. 234 1369 (1959). 



" Vincent W. Cochrane, "Physiology of Fungi," John Wiley and 

 Sons, Inc., New York, N. Y. 1958, pp. 131-135. 



1" Nathan Entner and Michael DoudorofF, /. Biol. Chem. 196 853 

 (1952); Joseph MacGee and Michael DoudorofF, ibid. 210 617 (1954). 



" Frank Eisenberg, Jr. and Samuel Gurin, J. Biol. Chem. 195 317 

 (1952); Frank Eisenberg, Jr., ibid. 212 501 (1955). 



1- J. F. Wilkinson, Nature 180 995 (1957); Stanton Segal and Yale 

 J. Topper, Biochim. et BiopJiys. Acta 25 419 (1957). 



1^ Luis F. Leloir and Carlos E. Cardini, Biochim.. et Biophys. Acta 

 12 15 (1953). 



