title: Biocatalytic racemization of aliphatic, arylaliphatic, and aromatic alpha-hydroxycarboxylic acids.
abstract: [reaction: see text] Biocatalytic racemization of a range of aliphatic, (aryl)aliphatic, and aromatic alpha-hydroxycarboxylic acids was accomplished by using whole resting cells of a range of Lactobacillus spp. The mild (physiological) reaction conditions ensured an essentially "clean" isomerization in the absence of side reactions, such as elimination or decomposition. Whereas straight-chain aliphatic 2-hydroxycarboxylic acids were racemized with excellent rates (up to 85% relative to lactate), steric hindrance was observed for branched-chain analogues. Good rates were observed for aryl-alkyl derivatives, such as 3-phenyllactic acid (up to 59%) and 4-phenyl-2-hydroxybutanoic acid (up to 47%). In addition, also mandelate and its o-chloro analogue were accepted at a fair rate (45%). This biocatalytic racemization represents an important tool for the deracemization of a number of pharmaceutically important building blocks.
authors.affiliation: Department of Chemistry, Organic and Bioorganic Chemistry, University of Graz, Heinrichstrasse 28, A-8010 Graz, Austria.
authors.forename: Silvia M
authors.initials: SM
authors.lastname: Glueck
authors.forename: Monika
authors.initials: M
authors.lastname: Pirker
authors.forename: Bettina M
authors.initials: BM
authors.lastname: Nestl
authors.forename: Barbara T
authors.initials: BT
authors.lastname: Ueberbacher
authors.forename: Barbara
authors.initials: B
authors.lastname: Larissegger-Schnell
authors.forename: Katrin
authors.initials: K
authors.lastname: Csar
authors.forename: Bernhard
authors.initials: B
authors.lastname: Hauer
authors.forename: Rainer
authors.initials: R
authors.lastname: Stuermer
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Kroutil
authors.forename: Kurt
authors.initials: K
authors.lastname: Faber
mesh_terms: D000818:Animals; D001419:Bacteria / Q000201:enzymology*; D002384:Catalysis; D005227:Fatty Acids / Q000737:chemistry* / Q000378:metabolism; D006841:Hydrocarbons, Aromatic / Q000737:chemistry / Q000378:metabolism; D006880:Hydroxy Acids / Q000737:chemistry* / Q000378:metabolism; D007778:Lactobacillus / Q000201:enzymology; D013237:Stereoisomerism
chemical_list: D005227:Fatty Acids; D006841:Hydrocarbons, Aromatic; D006880:Hydroxy Acids