Cinnabarinic acid

FIGURE 14.5 Laccase and cinnabarinic acid production during growth of P. cirmabarinus. (From Eggert, C., Temp, U., Dean, J.F.D., and Eriksson, K-E.L., FEES Lett, yKi, 202-206, 1995. With permission.)... 

C Eggert, U Temp, JFD Dean, K-EL Eriksson. Laccase-mediated formation of the phenoxazinone derivative, cinnabarinic acid. EEBS Lett 376 202-206, 1995. 

S Christen, P Southwell-Keely, R Stocker. Oxidation of 3-hydroxyanthranUic acid to the Phenoxazinone cinnabarinic acid by peroxyl radicals and by compound 1 of peroxidases or catalase. Biochemistry 31 8090-8097, 1992. 

Mention is made that vitamin C seems to be effective against bladder cancer, with studies cited. An interesting example is furnished of petrochemical plant workers whose urine would give off light, the phenomenon of chemiluminescence, and which was indicative of bladder cancer. Vitamin C countered this, presumably by preventing the formation of cinnabarinic acid, which is associated with tumor formation. 

Fig. (2). The (auto)oxidation pathway of 3-hydroxyanthranilic acid, leading to cinnabarinic acid...

Hydroxykinurenine Hydroxyanthranilic acid Cinnabarinic acid Xanthommatins... 

Fungus Pigments VIII. The Structure of Cinnabarin and Cinnabarinic Acid. Acta Chem. Scand. 12, 603 (1958). 

Phenoxazinone synthase (PHS) was first identified in extracts of S. antibioticus by Katz and Weissbach (15). The enzyme was shown to catalyze the oxidative condensation of two molecules of 2-aminophenol and its derivatives to yield the relevant phenoxazinone (Figure 3). Thus, the enzyme can catalyze the condensation of 3-HA or 4-MHA to yield cinnabarinic acid or actinocin, respectively, and will also function with 3-HA or 4-MHA peptides to yield actinocinyl peptides (26). At one time, it was thought that the actinocinyl peptides were intermediates in the acm biosynthetic pathway, but the work of Keller and coworkers, described in this chapter, argues strongly for the condensation of 4-MHA pemapeptides as the ultimate or penultimate step in the process. 

Numerous biocatalytic arene dimerizations mediated by laccases are also described. 3-Hydroxyanthranilic acid 148 is a natural substrate for oxidative dimerization by fungal laccases to give cinnabarinic acid 149, and the applicability of this transformation to other nonnatural substrates has been demonstrated (e.g., 150 to 151) [79, 80]. Crossed dimers arising from the oxidative coupling of two different hydroxyaniline substrates have also been reported [81]. Some more unusual examples of laccase-mediated oligomerizations include the oxidative dimerization/ cyclization of tyrosol 152 to give 153 [82] and the oxidative trimerization of indole 154 to give... 

SuBBA Rao, P. V., N. S. Jegannathan, and C. S. Vaidyanathan The conversion of 3-hydroxyanthranihc acid to cinnabarinic acid by the nuclear fraction of rat liver. Biochem. Biophys. Research Commun. 16, 145 (1964). 

Cinnabarin [polystictin, 2-amino-9-(hydroxymethyl)-3-oxo-3W-phenoxazine-1 -carboxylic acid]. 

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