Linked Life Data

12382047

Source:http://linkedlifedata.com/resource/pubmed/id/12382047

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1-2
pubmed:dateCreated
2002-10-16
pubmed:abstractText
(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 degrees C to 6 degrees 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 degrees 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.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Oct
pubmed:issn
0175-7598
pubmed:author
pubmed:issnType
Print
pubmed:volume
60
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
94-100
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
2002
pubmed:articleTitle
Enzymatic (R)-phenylacetylcarbinol production in benzaldehyde emulsions.
pubmed:affiliation
School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney NSW 2052, Australia. B.Rosche@unsw.edu.au
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't