Decarboxylases benzoyl formate decarboxylase

The mandelate and jS-ketoadipate pathways are a good example of gene duplication, with strong evidence of the former evolving from the latter the congruence of MR and MLE, (S)-ManDH and benzoate dihydrodiol dehydrogenase, and possibly benzoyl formate decarboxylase and protocatechuate decarboxylase. 

Benzoyl formate decarboxylase from Pseudomonas putida has been used to synthesize chiral 2-hydroxy ketones and bis(a-hydroxy) ketones, which find their use as pharmaceutical intermediates and as new multidentate ligands for asymmetric transition metal catalysis, respectively.272 273 Combining this decarboxylase activity with AdH has allowed all the stereoisomers of 1 -phenyl-propane- 1,2-diol to be synthesized.274... 

Aldol condensation Aldehyde 2-Keto aoid Synthesis of 2-hydroxy ketones Pyruvate decarboxylase, benzoyl formate deoarboxylase, phenylpyruvate deoarboxylase... 

M. Knoll, M. Muller, J. Pleiss, M. Pohl, Factors mediating activity, selectivity, and substrate specificity for the thiamin diphosphate-dependent enzymes benzaldehyde lyase and benzoyl-formate decarboxylase, Chembiochem 7 (2006) 1928-1934. 

III. BENZOYL FORMATE DECARBOXYLASE A. Properties of Benzoylformate Decarboxylase... 

The mandelate pathway in Pseudomonas putida involves successive oxidation to benzoyl formate and benzoate, which is further metabolized via catechol and the 3-ketoadipate pathway (Figure 8.35a) (Hegeman 1966). Both enantiomers of mandelate were degraded through the activity of a mandelate racemase (Hegeman 1966), and the racemase (mdlA) is encoded in an operon that includes the next two enzymes in the pathway—5-mandel-ate dehydrogenase (mdlB) and benzoylformate decarboxylase (mdlC) (Tsou et al. 1990). 

The potential of benzoylformate decarboxylase (BFD, E.C. 4.1.1.7) to catalyze C-C bond formation was first reported by Wilcocks at al. using crude extracts of Pseudomonas putidsL [50]. They observed the formation of (S)-2-hydroxy-l-phenylpro-panone (S)-2-HPP when benzoyl formate was decarboxylated in the presence of acetaldehyde. Advantageously, aldehydes - without a previous decarboxylation step - can be used instead of the corresponding more expensive a-keto acids [51]. We could show that BFD is able to bind a broad range of different aromatic, heteroaromatic, and even cyclic aliphatic and conjugated olefinic aldehydes to ThDP before ligation to acetaldehyde or other aldehydes (Table 2.2.7.3) [52]. 

The a-keto acid decarboxylases such as pyruvate (E.C. 4.1.1.1) and benzoyl formate (E.C. 4.1.1.7) decarboxylases are a thiamine pyrophosphate (TPP)-dependent group of enzymes, which in addition to nonoxidatively decarboxylating their substrates, catalyze a carboligation reaction forming a C-C bond leading to the formation of a-hydroxy ketones.269-270 The hydroxy ketone (R)-phenylacetylcarbinol (55), a precursor to L-ephedrine (56), has been synthesized with pyruvate decarboxylase (Scheme 19.35). BASF scientists have made mutations in the pyruvate decarboxylase from Zymomonas mobilis to make the enzyme more resistant than the wild-type enzyme to inactivation by acetaldehyde for the preparation of chiral phenylacetylcarbinols.271... 

Benzaldehyde can be produced from benzoyl formate with whole cells of Pseudomonas putida ATCC 12633 as biocatalyst119 201 (Fig. 16.6-5). Alternatively, but less effectively, mandelic acid can be used as starting material. A pH of 5.4 was found to be optimal for benzaldehyde accumulation. At this proton concentration, partial inactivation of the benzaldehyde dehydrogenase isoenzymes and activation of the benzoyl formate decarboxylase are reported. Fed-batch cultivation prevented substrate inhibition. In situ product removal is necessary to prevent product inhibition. 

Benzoylformate decarboxylase (BFD) from P. putida (Table 10.4, entries 1-5) catalyzes the acyloin condensation of benzaldehyde or benzoyl formate derivatives to acetaldehyde, furnishing (S)-configured acyloins. BDF showed a preference for aromatic aldehydes as donors and aliphatic aldehydes as acceptors, although with lower reaction rates than BAL [14,55], The meta- and para-substituted benzaldehyde derivatives as well as heteroaromatic, olefinic, and cyclic aliphatic aldehydes are transformed with good to excellent conversions and enantioselectivities [14,55,56,63,64]... 

Various enzymes, lysozyme, catalase, phosphatase, malate/formate dehydrogenase, adenylase kinase, pymvate decarboxylase, alkaline phospatase, serum albumin, lipoprotein, interferon, growth factor, polypeptide hormone DNA, RNA, y-globulin, proteinase, carboxypeptidase, endotoxins, pyrogen, IgG, trypsin inhibitor, transferrin, casein, L-benzoyl arginine ethyl ester, cytocrome C IgG, heparin... 

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