Ž . Journal of Molecular Catalysis B: Enzymatic 6 1999 145–159 Review Synthetic potential of thiamin diphosphate-dependent enzymes 1 Georg A. Sprenger a, ) , Martina Pohl b a Institut fur Biotechnologie 1, Forschungszentrum Julich, P.O. Box 1913, D-52425 Julich, Germany ¨ ¨ ¨ b Institut fur Enzymtechnologie der Heinrich-Heine-UniÕersitat Dusseldorf im Forschungszentrum, Julich, Germany ¨ ¨ ¨ ¨ Received 23 February 1998; revised 6 April 1998; accepted 7 April 1998 Abstract Ž . Thiamin diphosphate-dependent enzymes mainly pyruvate decarboxylase, transketolase, benzoylformate decarboxylase are increasingly being used to perform regio- and enantioselective reactions in chemoenzymatic syntheses. To utilize enzymes for unphysiological reactions and to yield novel products, a broad substrate spectrum is desirable. We give an overview of the use of these enzymes in biotransformations and in chemoenzymatic syntheses including multi-enzyme approaches which involve thiamin diphosphate-dependent enzymes as biocatalysts to obtain pharmaceutical compounds as ephedrine and glycosidase inhibitors, sex pheromones as exo-brevicomin, 13 C-labelled metabolites, and other intermediates as 1-deoxyxylulose 5-phosphate, a precursor of vitamins and isoprenoids. q 1999 Elsevier Science B.V. All rights reserved. Keywords: Thiamin diphosphate; Transketolase; Pyruvate decarboxylase; Benzoylformate decarboxylase: 1-deoxyxylulose 5-phosphate; Acyloin condensations; Phenylacetyl carbinol; Site-directed mutagenesis; a-hydroxyketones 1. Introduction Due to their intrinsic chiral function, en- zymes are finding increasing acceptance as cata- lysts in pure and applied chemistry. As the demand for enantiomerically pure compounds, Abbreviations: 3D, three-dimensional; BFDPs.p., Benzoylfor- mate decarboxylase from Pseudomonas putida; DHAS, dihydrox- yacetone synthase; DXS, 1-deoxyxylulose 5-phosphate synthase; Ž . Ž . 2-HPP, 2-hydroxypropiophenon; R -PAC, R -1-hydroxy-1- phenylpropan-2-one; PDC S.c., pyruvate decarboxylase from Sac- charomyces cereÕisiae; PDC S.u., pyruvate decarboxylase from Saccharomyces uÕarum; PDC Z.m., pyruvate decarboxylase from Zymomonas mobilis; RAMA, rabbit muscle aldolase; S. sp., Sac- charomyces species; ThDP, thiamin diphosphate; wt, wild-type; TKT, transketolase ) Corresponding author. Tel.: q49-2461-616205; fax: q49- 2461-612710; e-mail: g.sprenger@fz-juelich.de. 1 Dedicated to Professor Hideaki Yamada in honor of his 70th birthday. e.g., pharmaceutical products, is increasing, en- zymes will also be looked at for further applica- tions. Especially in the field of carbohydrate chemistry, the inherent multifunctionality of sugars is an enormous challenge for organic chemists who have to approach carbohydrate syntheses with protective groups in order to prevent undesired reactions of the various hy- droxyl-, keto-, or phosphate groups. So far, mainly lyases and aldolases have been used to synthesize complex sugars, sugar analogues and other biologically important natural compounds w x Ž . 1–8 . Thiamin diphosphate ThDP -dependent enzymes include the potential of both breaking w x and formation of C–C bonds 9–11 and have been used for quite a while as catalysts in w x Ž chemoenzymatic syntheses 3,7,8,12,13 for re- w x. cent reviews, see Refs. 14,15 . The spectrum 1381-1177r99r$ - see front matter q 1999 Elsevier Science B.V. All rights reserved. Ž . PII: S1381-1177 98 00107-6