527-07-1Relevant articles and documents
Expanding the scope of laccase-mediator systems
Koenst, Paul,Kara, Selin,Kochius, Svenja,Holtmann, Dirk,Arends, Isabel W. C. E.,Ludwig, Roland,Hollmann, Frank
, p. 3027 - 3032 (2013)
The laccase-mediator system (LMS) for the regeneration of oxidised nicotinamide co-factors was revisited to broaden the mediator scope. Among the 18 mediators screened, acetosyringone, syringaldehyde and caffeic acid excelled with respect to activity and stability under process conditions. The LMS based on the laccase from Myceliophthora thermophila and acetosyringone was further investigated and applied to promote the nicotinamide adenine dinucleotide (NAD+)-dependent oxidation of glucose as well as the oxidative lactonisation of 1,4-butanediol to the corresponding γ-butyrolactone. Laccase gets a look-in: The laccase-mediator system (LMS) for the regeneration of oxidized nicotinamide co-factors is revisited to broaden the mediator scope. The LMS based on the laccase from Myceliophthora thermophila and acetosyringone is applied to promote the oxidation of glucose and the oxidative lactonization of 1,4-butanediol to the corresponding γ-butyrolactone.
Nonenzymatic and metal-free organocatalysis for in situ regeneration of oxidized cofactors by activation and reduction of molecular oxygen
Zhu, Chenjie,Li, Qing,Pu, Lingling,Tan, Zhuotao,Guo, Kai,Ying, Hanjie,Ouyang, Pingkai
, p. 4989 - 4994 (2016)
The application of synthetic flavinium organocatalysts for the in situ regeneration of oxidized cofactors NAD(P)+ using O2 as the terminal oxidant without any special illumination or equipment is reported. With the aid of the highly active bridged flavinium catalyst, the rate of NAD(P)H oxidation is accelerated by 3 orders of magnitude. The results show that the catalytic activity of the bridged flavinium catalyst is not dependent on light but on only oxygen. Furthermore, this catalyst is compatible with various preparative enzymatic oxidation reactions. A hydride transfer mechanism is proposed for the presented system.
Gold Catalysis and Photoactivation: A Fast and Selective Procedure for the Oxidation of Free Sugars
Omri, Mehdi,Sauvage, Frédéric,Busby, Yan,Becuwe, Matthieu,Pourceau, Gwladys,Wadouachi, Anne
, p. 1635 - 1639 (2018)
A fast and efficient methodology for the selective oxidation of sugars into corresponding sodium aldonates is herein reported. Hydrogen peroxide was used as a cheap oxidant and electron scavenger, in the presence of only 0.003-0.006 mol % of gold in basic conditions. Three photocatalysts were studied, namely Au/Al2O3, Au/TiO2, and Au/CeO2, the latter being the most efficient (TOF > 750 000 h-1) and perfectly selective. Only a 10 min exposition under standard incident sunlight irradiation (A.M.1.5G conditions, 100 mW/cm2) affords total conversion of glucose into the corresponding sodium gluconate. Demonstrating its versatility, this methodology was successfully applied to a variety of oligosaccharides leading to the corresponding aldonates in quantitative yield and high purity (>95%) without any purification step. The photocatalyst was recovered by simple filtration and reused 5 times leading to the same conversion and selectivity after 10 min of illumination.
Effect of reduction method on the performance of Pd catalysts supported on activated carbon for the selective oxidation of glucose
Chen, Kangcheng,Pan, Yunxiang,Liu, Changjun
, p. 1598 - 1602 (2010)
The effect of the reduction method on the catalytic properties of palladium catalysts supported on activated carbon for the oxidation of D-glucose was examined. The reduction methods investigated include argon glow discharge plasma reduction at room temperature, reduction by flowing hydrogen at elevated temperature, and reduction by formaldehyde at room temperature. The plasma-reduced catalyst shows the smallest metal particles with a narrow size distribution that leads to a much higher activity. The catalyst characteristics show that the plasma reduction increases the amount of oxygen-containing functional groups, which significantly enhances the hydrophilic property of the activated carbon and improves the dispersion of the metal.
C1 Oxidation/C2 Reduction Isomerization of Unprotected Aldoses Induced by Light/Ketone
Masuda, Yusuke,Tsuda, Hiromu,Murakami, Masahiro
supporting information, p. 2755 - 2759 (2020/01/25)
Unprotected aldoses in water undergo an isomerization reaction via a radical pathway when irradiated with light in the presence of water-soluble benzophenone. Whereas its anomeric carbon (C1) is oxidized to a carboxy group, the hydroxy group on the C2 carbon is replaced by hydrogen. The generated 2-deoxy lactones are readily reduced to the corresponding 2-deoxy aldoses, which are often contained in bioactive compounds.
