Oxidoreductases cresol oxidoreductase

Table 16.3-11. Substrates and products of4-cresol-oxidoreductase 25, 261. Substrate Product Substrate Product...

The reaction mechanism is quite similar to the one of VAO and also includes an intermediate, the para-quinone methide. Like VAO, 4-cresol-oxidoreductase also exhibits a high enantioselectivity for (S)-l-(4 -hydroxyphenyl)alkylalcohols1591. 

Ethylphenol oxidoreductase from Pseudomonas putida JD1 is structurally almost identical to 4-cresol oxidoreductase, but catalyzes the hydroxylation of para-alkylphe-nols with longer aliphatic chains (Table 16.3-12). The hydroxylation reactions enantioselectively produce (-R)-alcohols 64> 65l The regeneration properties of this enzyme are quite similar to 4-cresol oxidoreductase1611. 

Hopper, D. J., and Taylor, D. G., 1977, The purification and properties of p-cresol-(acceptor) oxidoreductase (hydroxylating), a flavocytochrome from Pseudomonas putida. Biochem. J. 167 155nl62. 

Polymer Modification by Oxidoreductases. Tyrosinase (polyphenol oxidase, a copper-containing monooxygenation enzyme) was used as catalyst for modification of chitosan. The enzymatic treatment of chitosan film in the presence of tyrosinase and phenol derivatives produced a new material of chitosan derivative (309). During the reaction, imstable o-quinones were formed, followed by the reaction with chitosan to give the modified chitosan. In the enzymatic treatment of p-cresol with a low concentration of chitosan (<1%), the reaction solution was converted into a gel (310). 

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