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Hydrolysis of N-benzyloxycarbonyl-3,4-epoxy-pyrrolidine and cyclohexene oxide with the epoxide hydrolase of Sphingomonas sp. HXN-200, respectively, gave the corresponding vicinal trans-diols in high ee and yield, representing the first example of enantioselective hydrolysis of a meso-epoxide with a bacterial epoxide hydrolase.

A recombinant Escherichia coli expressing P450 pyr monooxygenase of Sphingomonas sp. HXN-200 was developed as a useful biocatalyst for regioand stereoselective hydroxylations, with no side reaction and easy cell growth. The resting E. coli cells showed an activity of 4.1 U/g cdw and 9.9 U/g cdw for the hydroxylation of N-benzylpyrrolidin-2-one 1 and N-benzyloxycarbonylpyrrolidine 3, respectively, being as active as the wide-type strain. Biohydroxylation of N-benzylpyrrolidin-2-one 1 with the resting cells gave (S)-N-benzyl-4-hydroxypyrrolidin-2-one 2 in > 99% ee and 10.8 mM, a 2.6 times increase of product concentration in comparison with the wildtype strain. Biohydroxylation of N-tert-butoxycarbonylpiperidin-2-one 5, N-benzylpiperidine 7 and Ntert-butoxycarbonylazetidine 9 with the E. coli cells afforded the corresponding 4-hydroxypiperidin-2-one 6, 4-hydroxypiperidine 8, and 3-hydroxyazetidine 10 in 14 mM, 17 mM, and 21 mM, respectively. Moreover, hydroxylation of (À)-b-pinene 11 with the recombinant E. coli cells showed excellent regio-and stereoselectivity and gave (1R)-trans-pinocarveol 12 in 82% yield and 4.1 mM, which is over 200 times higher than that obtained with the best biocatalytic system known thus far. The recombinant strain was also able to hydroxylate other types of substrates with unique selectivity: biohydroxylation of norbornane 13 gave exo-norbornaeol 14, with exo/endo selectivity of 95%; tetralin 15 and 6-methoxytetralin 17 were hydroxylated at the non-activated 2-position, for the first time, with regioselectivities of 83-84%.

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