Frederick G. Holliman

Pigments of Pseudomonas species. Part V. Biosynthesis of pyocyanin and the pigments of Ps. aureofaciens

Tracer experiments have shown that phenazine-1-carboxylic acid and its 5-methyl betaine are incorporated into pyocyanin by Ps. aeruginosa by decarboxylative hydroxylation. Phenazine-1,6-dicarboxylic acid is not incorporated. 2-Hydroxyphenazine-1-carboxylic acid and 2-hydroxyphenazine are derived from phenazine-1-carboxylic acid in Ps. aureofaciens but not from 5-methylphenazinium-1-carboxylate.

The biosynthesis of phenazines: Incorporation of phenazine-1,6-dicarboxylic acid in ether-treated cells of pseudomonas aureofaciens

Ether treatnent of pseudomonas aureofaciens cells facilitates assimilation of phenazine-1,6-d1carboxylic acid (1) and (1) is shown to be an efficient and specific precursor for phenazine-1-carboxylic acid.

The biosynthesis of phenazines: incorporation of [14C]shikimic acid

Specific and self-consistent incorporations of [1-14C]-, [6-14C]-, and [1,6,7-14C3]-shikimic acid into iodinin in Brevibacterium iodinum closely define the orientation of the precursor molecule in the phenazine metabolite. [1,6,7-14C3]Shikimic acid gave phenazine-1-carboxylic acid with one fifth of the activity in the carboxy-group, which requires the involvement of two precursor molecules in biosynthesis or incorporation via a symmetrical intermediate derived from only one precursor molecule. Neither [3H]anthranilic acid nor [14C]dihydrohydroxyanthranilic acid was significantly incorporated into iodinin. Decarboxylation of [ring-14C]pyrazinetetracarboxylic acid under various conditions has been studied; with copper chromite, but not with copper–bipyridyl–quinoline, radioactivity (up to 12%) appeared in the liberated carbon dioxide.

Synthesis of some methoxy- and hydroxy-phenazine-1-carboxylic acids

The synthesis of the naturally occuring 6- and 9-hydroxyphenazine-1-carboxylic acids, (3) and (4), is described. Methyl 6-methoxyphenazine-1-carboxylate (12) is identified as a metabolite from Streptomyces luteoreticuli, and a metabolite of Pseudomonas aureofaciens is identified as 2-hydroxyphenazine-1-carboxylic acid (2) by comparison with synthetic material.