53584-56-8Relevant articles and documents
α-Hydroxy-β-keto acid rearrangement-decarboxylation: Impact on thiamine diphosphate-dependent enzymatic transformations
Beigi, Maryam,Loschonsky, Sabrina,Lehwald, Patrizia,Brecht, Volker,Andrade, Susana L.A.,Leeper, Finian J.,Hummel, Werner,Müller, Michael
, p. 252 - 256 (2013)
The thiamine diphosphate (ThDP) dependent MenD catalyzes the reaction of α-ketoglutarate with pyruvate to selectively form 4-hydroxy-5-oxohexanoic acid 2, which seems to be inconsistent with the assumed acyl donor role of the physiological substrate α-KG. In contrast the reaction of α-ketoglutarate with acetaldehyde gives exclusively the expected 5-hydroxy-4-oxo regioisomer 1. These reactions were studied by NMR and CD spectroscopy, which revealed that with pyruvate the observed regioselectivity is due to the rearrangement-decarboxylation of the initially formed α-hydroxy-β-keto acid rather than a donor-acceptor substrate role variation. Further experiments with other ThDP-dependent enzymes, YerE, SucA, and CDH, verified that this degenerate decarboxylation can be linked to the reduced enantioselectivity of acyloins often observed in ThDP-dependent enzymatic transformations.
An artificial enzymatic reaction cascade for a cell-free bio-system based on glycerol
Gao, Chao,Li, Zhong,Zhang, Lijie,Wang, Chao,Li, Kun,Ma, Cuiqing,Xu, Ping
supporting information, p. 804 - 807 (2015/03/04)
Conversion of glycerol into high-value products is of significant importance for sustainability in the biofuel industry. In this study, pyruvic acid, a central intermediate needed for the production of versatile biomolecules, was produced from glycerol without the addition of any cofactors by the cell-free bio-system composed of alditol oxidase, dihydroxy acid dehydratase, and catalase. (3R)-Acetoin was then produced at 85.5% of the theoretical yield from glycerol by α-acetolactate synthase and α-acetolactate decarboxylase. Since other biomolecules can also be produced from pyruvic acid, the cell-free bio-system might serve as a versatile bio-production platform, and support the viability of the biofuel economy. This journal is
Enantioselective hydrogenation of activated ketones in the presence of Pt-cinchona catalysts. Is the proton transfer concept valid?
Margitfalvi, József L.,Tálas, Emília
, p. 142 - 145 (2014/01/17)
Experimental evidences related to the proton transfer in the catalytic system Pt-cinchona alkaloids for enantioselective hydrogenation of activated ketones were collected and analyzed. Both new and earlier results indicate that in aprotic media direct transfer of proton from platinum to the substrate with the involvement of quinuclidine nitrogen as a general rule can be questioned.
