Kynurenic acid oxygenase

In most hydroxylation reactions TPNH appears to be a specific electron donor (Tables IV and V), but in certain instances, especially in microbial systems, DPNH is a preferred or specific electron donor. For example, imidazole-acetic acid oxygenase (Rothberg and Hayaishi, 1957) is specific for DPNH, and kynurenic acid oxygenase (Taniuchi... 

Kynurenic oxygenase Pseudomonas Kynurenic acid Kynurenic add 7,8-di- Taniuchi et al. (1960)... 

The oxidation of tryptophan by various strains of Pseudomonas has been shown to proceed in all cases via kynurine. One sequence of reactions, the aromatic pathway, continues by eliminating the alanine side chain through the action of kynureninase, and subsequently utilizes oxygen for the formation of catechol and the pyrocatechase reaction already discussed. Another pathway retains the side chain of kynurenine and forms kynurenic acid through the action of kynurenine transaminase. A sequence of reactions has been indicated by recent work of Hayaishi and his associates (Kuno et al., 1961) this sequence appears to include three oxygenase reactions one hydroxylation and two phenolytic oxygenations (Fig. 18). 

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