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both yeast (Candida utilis) and pyruvate
decarboxylase (PDC)

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What type of home brewing are these used for?

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© Springer-Verlag 2002

Original Paper

Enzymatic (R)-phenylacetylcarbinol production in benzaldehyde emulsions

B. Rosche1, , N. Leksawasdi1, V. Sandford1, M. Breuer2, B. Hauer2 and P. Rogers1

(1)
School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney NSW 2052, Australia

(2)
BASF-AG, Hauptlaboratorium, 67056 Ludwigshafen, Germany

Abstract. (R)-Phenylacetylcarbinol [(R)-PAC)] is the chiral precursor for the production of the pharmaceuticals ephedrine and pseudoephedrine. Reaction conditions were improved to achieve increased (R)-PAC levels in a simple batch biotransformation of benzaldehyde emulsions and pyruvate, using partially purified pyruvate decarboxylase (PDC) from the filamentous fungus Rhizopus javanicus NRRL 13161 as the catalyst. Lowering the temperature from 23°C to 6°C decreased initial rates but increased final (R)-PAC concentrations. Addition of ethanol, which increases benzaldehyde solubility, was not beneficial for (R)-PAC production. It was established that proton uptake during biotransformation increases the pH above 7 thereby limiting (R)-PAC production. For small-scale studies, biotransformations were buffered with 2-2.5 M MOPS (initial pH 6.5). High concentrations of MOPS as well as some alcohols and KCl stabilised PDC. A balance between PDC and substrate concentrations was determined with regards to (R)-PAC production and yields on enzyme and substrates. R. javanicus PDC (7.4 U/ml) produced 50.6 g/l (337 mM) (R)-PAC in 29 h at 6°C with initial 400 mM benzaldehyde and 600 mM pyruvate. Molar yields on consumed benzaldehyde and pyruvate were 97% and 59%, respectively, with 17% pyruvate degraded and 24% converted into acetaldehyde and acetoin; 43% PDC activity remained, indicating reasonable enzyme stability at high substrate and product concentrations.



E-mail: B.Rosche@unsw.edu.au
Phone: +61-2-93853895
Fax: +61-2-93136710

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some perhaps valuable information on L-PAC:

L-PAC, aka laevo-phenylacetylcarbinol, is also named:

1-hydroxy-1-phenyl-2-propanone
1-hydroxy-1-phenylpropanone
l-1-phenylpropan-1-ol-2-on (phenylpropanolon)    -> old german
laevo-phenylpropanolone
1-phenyl-2-ketoalcohol-(1)
1-phenyl-propanol-1-one-2
R-PAC

I am sure the babylonians have still more names for this simple compound. If somebody finds another one - PM me.

Also is this molecule well known since 1921, and heavily used in pharmaceutic industry, but there is no entry at chemfinder or another public database I have access.

Please, somebody who has access to better resources could look up the properties (boiling point, soluble in...)? Post them here or/and PM me?
THANKS!
Racemisation in basic solution is very fast, thats what I could dig up.

IMHO biotransformations are a sharp sword in the hand of clandestine chemistry. And I don´t speak of genetically engineered or otherwise dangerous organisms. All day everywhere yeasts are keeping a widely undeveloped (or not published) power of transformation. Enzyme extraction isn´t rocket science also.

I will be happy if I would get the L-PAC properties
ORGY