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References 309

amidase. However, the matching of the substrate profile and enantioselectivity
for this two enzyme combination may require the use of selected enzymes from
more than one microbial strain, necessitating heterologous expression in a host
organism. A possible advantage of a two enzyme system is that the enantioselectivity
of the enzymes can be synergistic.
Another possible cascade reaction would be the combination of nitrilases and
transaminases, in principle again exploiting enantioselective synergy. Similarly the
combined use of nitrilases with acylases or lipases is conceivable, when working
with N-acylated substrates. However, the size of the acyl group should be compatible
with the nitrilase active site.

Acknowledgments

We would like to thank the European Science Foundation as well as the working
group leaders Dr. Ludmila Mart´ ınkov´ a and Prof. Andreas Stolz for the opportunity
to participate in COST Action CM0701 (Cascade Biocatalysis). Many thanks to L.
Rapheeha and Profs M.P. Roux-van der Merwe and J. Bezuidenhout of Tshwane
University of Technology for microbial strains, and Prof. N. Klempier and Dr.
M. Winkler of the University of Graz for technical inputs and discussions. This
work was supported financially by the Department of Science and Technology and
the CSIR.

References

1. Ma, D.-Y., Wang, D.-X., Pan, J., Huang, fluoxetine, atomoxetine and nisoxetine.
Z.-T., and Wang, M.-X. (2008) Nitrile Tetrahedron Lett., 48, 1217–1219.
biotransformations for the synthesis 5. Davies, S.G., Ichihara, O., Lenoir, I.,
of highly enantioenriched β-hydroxy and Walters, I.A.S. (1994) Asymmetric
and β-amino acid and amide deriva- synthesis of (−)-(1R,2S)-cispentacin
tives: a general and simple but powerful
and related cis-and trans-2-amino
and efficient benzyl protection strat-
cyclopentane- and cyclohexane-1-
egy to increase enantioselectivity of the
amidase. J. Org. Chem., 73, 4087–4091. carboxylic acids. J. Chem. Soc., Perkin
2. W¨ unsche, K., Schwaneberg, U., Trans. 1, 1411–1415.
Bornscheuer, U.T., and Meyer, H.H. 6. Steinhuebel, D., Sun, Y., Matsumura,
(1996) Chemoenzymatic route to K., Sayo, N., and Saito, T. (2009) Direct
β-blockers via 3-hydroxy esters. Tetra- asymmetric reductive amination. J. Am.
hedron: Asymmetry, 7, 2017–2022. Chem. Soc., 131, 11316–11317.
3. Kamal, A., Ramesh Khanna, G.B., 7. Holton, R.A., Somoza, C., Kim, H.-
Krishnaji, T., Tekumalla, V., and Ramu,
B., Liang, F., Biediger, R.J., Boatman,
R. (2005) New chemoenzymatic path- P.D., Shindo, M., Smith, C.C., Kim, S.,
way for β-adrenergic blocking agents.
Nadizadeh, H., Suzuki, Y., Tao, C., Vu,
Tetrahedron: Asymmetry, 16, 1485–1494.
P., Tang, S., Zhang, P., Murthi, K.K.,
4. Hammond, R.J., Poston, B.W.,
Ghiviriga, I., and Feske, B.D. (2007) Gentile, L.N., and Liu, J.H. (1994) First
Biocatalytic synthesis towards total synthesis of taxol. 1. Functional-
both antipodes of 3-hydroxy-3- ization of the B-ring. J. Am. Chem. Soc.,
phenylpropanitrile a precursor to 116, 1597–1598.