Biotransformation of quinoline, isoquinoline, quinoxaline and quinazoline using growing cultures of Pseudomonas putida UV4 yielded cis-dihydro diols from the oxidation of the carbocyclic aromatic ring. Aromatic hydroxylation was observed in both carbocyclic and heterocyclic rings. Ring cleavage of the quinoline skeleton to yield anthranilic acid, and cis-diol formation (with alkene bond reduction) to yield cis-5,6,7,8-tetrahydroquinazoline-5.6-diol from quinazoline were observed. The cis-dihydro diol metabolites of quinoline (5,6and 7,8-) and quinoxaline (5,6-) were found to be optically pure, while metabolism of isoquinoline gave one homochiral (5,6-) and one racemic (7.8-) cis-dihydro diol product. The absolute configurations of the cis-dihydro diol metabolites have been determined using ' H N M R analyses, stereochemical correlations and X-ray crystallography methods.Azaarenes (e.g. quinoline 1 and isoquinoline 2) are widely distributed throughout the global environment, mainly as a result of partial combustion of plant material and fossil fuels. 'Quinoline I, the most abundant of the azaarenes in the environment, is both carcinogenic and mutagenic. The latter effects probably result from the derived metabolites of quinoline 1. Known and potential metabolites of quinoline l 2 and isoquinoline 23 have recently been synthesised as part of a Paper 2/06567C

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Metabolism of the aza-arenes quinoline, isoquinoline, quinazoline, and quinoxaline by a mutant strain of the bacterium Pseudomonas putida resulted in attack at the carbocyclic ring (to yield stable cis-dihydrodiols and phenols) and at the heterocyclic ring (to yield phenols and ring cleavage products).

Selected strains of the bacterium Pseudomonas putida (previously shown to effect dioxygenase-catalysed asymmetric cis-dihydroxylation of alkenes) have been found to yield chiral sulfoxides from the corresponding sulfides with a strong preference for the (R)or (S)-configurations but without evidence of sulfone formation; similar results obtained using an Escherichia coliclone (pKST11, containing the Tod C1 C2 B and A genes encoding toluene dioxygenase from P. putida NCIMB 1 1767) are again consistent with a stereoselective dioxygenase-catalysed su Ifoxidation.

Metabolism of the bicyclic alkenes 1,2-dihydronaphthalene, indene, and 1,2-benzocyclohepta-l,3-diene by a mutant strain of fseudomonas putida yields benzylic monols (exclusively with R configuration) as major metabolites and vicinal cis diols as minor products having an excess of the S configuration at the benzylic position.