50I Phenazines and Phenoxazones 



A. J. Birch, R. A. Massy-Westropp and R. W. Rickards, 



;. Chem. Soc, 3717 (1956). 



A. J. Birch, Proc. Chem. Soc, 233 (1957). 



/. PHENAZINES AND PHENOXAZONES 



The phenazine bacterial pigments have been known for 

 many years. Pyocyanine was probably isolated in the 

 early 1860's, and oxychlororaphine was synthesized in 

 1930. New pigments of this type continue to be reported, 

 usually from pseudomonas species, but also from strepto- 

 mycetes. Pyocyanine is responsible for the blue-green 

 color of pus, since Pseudomonas aeruginosa is a skin para- 

 site, and certain other blue or green stains on natural ma- 

 terials have been identified with phenazine pigments. 



The phenazine bacterial pigments have been reviewed,^ 

 and this introduction will be confined to a few remarks on 

 biosynthesis. Actually, there is as yet little to be said on 

 this subject. Several studies have been made concerning 

 medium requirements and improvements for optimum 

 pigment production in both growing- and stationary cul- 

 tures.* In growing cultures a yield of 231 mg. of pyocya- 

 nine per liter was obtained on a medium containing glyc- 

 erol, D,L-alanine, L-leucine and magnesium, calcium, phos- 

 phate, sulfate and ammonium ions. 



In resting cultures glutamic acid and y-aminobutyric 

 acid were found to be the best substrates, yielding about 

 250 mg. of pyocyanine per liter. Pigment production was 

 slow and inhibited by respiratory poisons (cyanide, azide) 

 but not by fluoride. 



These results are not very helpful in speculations on 

 the biosynthetic intermediates. 



Viewed in aggregate there is a noticeable recurrence of 

 either hydroxyl or carboxyl groups at the 1-position, the 

 9-position or the 6-position of the phenazine nucleus. 



^ G. A. Swan and D. G. I. Felton, "Phenazines," Interscience Pub- 

 lishers, Inc., New York, 1957, pp. 174-191. 



- M. O. Burton, J. J. R. Campbell and B. A. Eagles, Can. J. Res. 

 26C 15 (1948); M. O. Burton, B. A. Eagles and J. J. R. Campbell, 

 ibid. 25C 121 (1947); G. Young, /. Bacteriol. 54 109 (1947); Esther 

 HeUinger, J. Gen. Microbiol. 5 633 (1951). 



^ N. Grossowicz, Peyuta Hayat and Y. S. Halpern, /. Gen. Microbiol. 

 16 576 (1957). 



