Poly aromatic dioxygenase

Following the application of 3-cresol and anisole, induction of P. putida TVA8 was achieved and there are some studies (e.g., Boyd and Sheldrake, 1998), suggesting several substrates and mono- and poly-cyclic aromatic rings may be cleaved by toluene dioxygenase. Other cyclic compounds (e.g., pyrrole, pyridine, and furan) also induce P. putida TVA8, but the specific mechanism and enzymes involved are unknown. Further studies on this aspect are required to comprehensively address this question. 

Abstract This chapter describes the production of cis-3,5-cyclohexadiene-l,2-diol (DHCD) from aromatic compounds, their polymerization into poly(p-phenyelene) (or PPP), and the properties and applications of the polymer. Large-scale synthesis of DHCD has been demonstrated, and DHCD is widely used in the pharmaceutical industry, as well as in chemical industries for polymer productions. Recent study including different types of dioxygenases, strain development by recombination, and genetical modification were done to develop the process technology for commercialization of this new polymer and chemical intermediates. 

Kim SY, Jung J, Lim Y, Ahn JH, Kim SI, Hur HG (2003) cis-2, 3 -Dihydrodiol production on flavone B-ring by biphenyl dioxygenase from Pseudomonas pseudoalcaUgenes KF707 expressed in Escherichia coU. Antonie Van Leeuwenhoek 84 261-268 Kovacic P, Jones MB (1987) Dehydro coupling of aromatic nuclei by catalyst-oxidant systems poly(p-phenylene). Chem Rev 87 357-379... 

Benzene c -diols, namely, cw-3,5-cyclohexadien-l,2-diols abbreviated as DHCD, can be used for synthesis of poly(para-phenylene) (PPP), which is a material with high thermal stability and electricity conducting ability when doped. Several types of bacterial dioxygenases, that can catalyze the conversion of aromatic componnds to their corresponding c -diols, which can be polymerized to form PPP, are discnssed. 

Synthesis of poly(catechol) was demonstrated by multienzymatic processes (Fig. 1) [13]. Aromatic compounds were converted to catechol derivatives by the catalytic action of toluene dioxygenase and toluene cis-dihydrodiol dehydrogenase, followed by the peroxidase-catalyzed polymerization to give the polymer with molecular weight of several thousands. 

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