Biotransformation of various substituted aromatic compounds to chiral dihydrodihydroxy derivatives

The biotransformation of four different classes of aromatic compounds by th e Escherichia coli strain DH5 alpha (pTCB 144), which contained the chlorob enzene dioxygenase (CDO) from Pseudomonas sp. strain P51, was examined. CDO oxidized biphenyl as well as monochlorobiphenyls to the corresponding cis- 2,3-dihydro2,3-dihydroxy derivatives, whereby oxidation occurred on the uns ubstituted ring. No higher substituted biphenyls were oxidized. The absolut e configurations of several monosubstituted cis-benzene dihydrodiols formed by CDO were determined. All had an S configuration at the carbon atom in m eta position to the substituent on the benzene nucleus. With one exception, the enantiomeric excess of several 1,4-disubstituted cis-benzene dihydrodi ols formed by CDO was higher than that of the products formed by two toluen e dioxygenases. Naphthalene was oxidized to enantiomerically pure (+)-cis- (1R,2S)-dihydroxy-1,2-dihydronaphthalene. All absolute configurations were identical to those of the products formed by toluene dioxygenases of Pseudo monas putida UV4 and P. putida F39/D. The formation rate of (+)-cis-(1R,2S) -dihydroxy-1,2-dihydronaphthalene was significantly higher (about 45 to 200 %) than those of several monosubstituted cis-benzene dihydrodiols and more than four times higher than the formation rate of cis-benzene dihydrodiol. A new gas chromatographic method was developed to determine the enantiomeri c excess of the oxidation products.