Monooxygenase styrene

Some of the major enzyme groups that facilitate this transformation are heme-containing MOs of the cytochrome P450 type [111], alkane hydroxylases, xylene monooxygenases, styrene monooxygenases [105], and haloperoxidases [112],... 

Styrene was successfully oxidized to the S-product both by xylene monooxygenase from P. putida mt-2 [113] and styrene monooxygenase from Pseudomonas sp.VLB120 [114] (Scheme 9.13), with the latter enzyme displaying a particularly large substrate tolerance with excellent stereoselectivity (>99% ee). In this context it is interesting to note that both xylene monooxygenase as well as chloroperoxidase are very selective for mono-epoxidation in case of presence of multiple alkene functionalities [115]. 

Cox HHJ, BW Faber, VNM van Heiningen, H Radhoe, HI Doddema, W Harder (1996) Styrene metabolism in Exophilia jeanselmei and involvement of a cytochrome P-450-dependent styrene monooxygenase. Appl Environ Microbiol 62 1471-1474. 

Hartmans S, MJ van der Werf, JAM de Bont (1990) Bacterial degradation of styrene involving a novel flavin adenenine dinucleotide-dependent styrene monooxygenase. Appl Environ Microbiol 41 1045-1054. 

Schmid, A., Hofstetter, K., Feiten, H.J., Holhnann, R, Witholt, B. (2001) Integrated Biocatalytic Synthesis on Gram Scale The Highly Enantio Selective Preparation of Chiral Oxiranes with Styrene Monooxygenase. Advanced Synthesis Catalysis, 343(6-7), I il-l il. 

Parrke, S., Held, M., Wubbolts, M.G., Witholt, B., Schmid, A. (2002) Pilot-Scale Production of (S)-Styrene Oxide from Styrene by Recombinant Escherichia coli Synthesizing Styrene Monooxygenase. Biotechnology and Bioengineering, 80, 33M1. 

G. Belvedere, L. Cantoni, T. Facchinetti, M. Salmona, Kinetic Behaviour of Microsomal Styrene Monooxygenase and Styrene Oxide Hydratase in Different Animal Species , Experientia 1977, 33, 708 - 709. 

It is interesting that NADH is also required as a stoichiometric co-factor in enzymatic oxygenation processes. In a detailed study of styrene monooxygenase (StyA), Andreas Schmid of the ETH/Zurich showed (J. Am. Chem. Soc. 125 8209,2003) that Cp Rh(bpy)(H 0)fc in combination with sodium formate served effectively to regenerate the NADH. Using this combination, epoxidation of aryl alkenes such as 6, 8 and 10 proceeded in high enantiomeric... 

Recently, the first asymmetric cell-free application of styrene monooxygenase (StyAB) from Pseudomonas sp. VLB 120 was reported [294]. StyAB catalyses the enantiospecific epoxidation of styrene-type substrates and requires the presence of flavin and NADH as cofactor. This two-component system enzyme consists of the actual oxygenase subunit (StyA) and a reductase (StyB). In this case, the reaction could be made catalytic with respect to NADH when formate together with oxygen were used as the actual oxidant and sacrificial reductant respectively. The whole sequence is shown in Fig. 4.106. The total turnover number on StyA enzyme was around 2000, whereas the turnover number relative to NADH ranged from 66 to 87. Results for individual substrates are also given in Fig. 4.106. Excellent enantioselectivities are obtained for a- and -styrene derivatives. 

Fig. 4.106 Biocatalytic epoxidation with styrene monooxygenase including cofactor regeneration.

The first example of a catalytic enantioselective epoxidation by cyclohexanone monooxygenase was shown with a fosfomycin-related model compound [75]. The efficient asymmetric epoxidation of styrene to (S)-styrene oxide by recombinant styrene monooxygenase has been achieved by increasing biocatalyst concentrations and reducing the exposure time of the biocatalyst to the product [76]. 

Kantz A, Chin F, Nallamothu N, Nguyen T, Gassner GT. Mechanism of flavin transfer and oxygen activation by the two-component flavoenzyme styrene monooxygenase. Arch. Bio-chem. Biophys. 2005 442 102-116. 

S. Panke, M. Held, M. G. Wubbolts, B. Witholt, A. Schmid, Pilot-scale production of (S)-styrene oxide from styrene by recombinant Escherichia coli synthesizing styrene monooxygenase, Biotechnol. Bioeng. 80 (2002) 33. 

A. Schmid, K. Hofstetter, H. J. Feiten, F. Hollmann, B. Witholt, Integrated biocatalytic synthesis on gram scale The highly enantioselective preparation of chiral oxiranes with styrene monooxygenase, Adv. Synth. Catal. 343 (2001) 732. 

Kinetic Behavior of Microsomal Styrene Monooxygenase and Styrene Epoxide Hydratase in Different Animal Species" Experientia (1977), 708-709. 

The following values for the pharmacokinetic parameters were scaled up from vitro determinations of styrene monooxygenase and epoxide hydratase activities in mouse liver (15). 

Scheme 18.18 Asymmetric epoxidation reaction cataiyzed by styrene monooxygenase.

Styrene monooxygenase activity with NADH or NADPH, except for strain S14 which only exhibited NADPH-dependent SMO activity, nd = Not determined. 

A similar approach for an improved in vivo cofactor recychng was published by Itoh and coworkers [20]. They combined a styrene monooxygenase (SMO) from Rhodococcus sp. [21] and an ADH from Leifsonia sp. for the efficient synthesis of chiral aryl epoxides starting from olefins (Scheme 3.4). They tested 19 different olefins and could convert substrates in titers ranging from 10 mM for very polar to 200 mM for nonpolar substances. 

Scheme 3.4 Schematic illustration of the production of chiral epoxides by styrene monooxygenase (SMO) and alcohol dehydrogenase from Leifionia sp. (LSADH).

Toda, FI., Imae, R., and Itoh, N. (2012) Efficient biocatalysis for the production of enantiopure (S)-epoxides using a styrene monooxygenase (SMO) and Leif-sonia alcohol dehydrogenase (LSADH) system. Tetrahedron Asymmetry, 23, 1542-1549. 

StyAl and StyA2B from Rhodococcus opacus ICP a multifunctional styrene monooxygenase system. J. Bacteriol.,... 

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