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.
Aerobic oxidation of glucose over gold nanoparticles deposited on cellulose
Ishida, Tamao,Watanabe, Hiroto,Bebeko, Takao,Akita, Tomoki,Haruta, Masatake
, p. 42 - 46 (2010)
Gold nanoparticles (NPs) with mean diameters of around 2 nm could be deposited directly onto a bio-polymer, cellulose, by the solid grinding method with volatile dimethyl Au(III)acetylacetonate followed by the reduction with H2. Gold NPs on cellulose showed appreciably high catalytic activity with a turnover frequency (TOF) of 11 s-1 for the aerobic oxidation of glucose to produce sodium gluconate at 60 °C and at pH 9.5. The catalytic activity of Au/cellulose was comparable to that of Au/C provided the size of the Au particles was similar.
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.
Efficient Oxidation of Glucose into Sodium Gluconate Catalyzed by Hydroxyapatite Supported Au Catalyst
Liu, Xianxiang,Yang, Yongjun,Su, Shengpei,Yin, Dulin
, p. 383 - 390 (2017)
Abstract: Gold nanoparticles (NPs) with mean diameters of around 2?nm were successfully deposited onto the inorganic support hydroxyapatite to give the Au/HAP catalyst. The Au/HAP catalyst showed appreciably high catalytic activity for the aerobic oxidation of glucose to produce sodium gluconate at room temperature. Glucose conversions of 100% and sodium gluconate yield of 90.9% were achieved after 1?h at room temperature by the use of 0.5 equiv. Na2CO3. The developed catalytic system was easily-handed for the production of sodium gluconate. In addition, the Au/HAP catalyst was stable and could be reused for several times without the loss of its catalytic activity. Graphical Abstract: Au/HAP catalyst showed high activity and stability on the aerobic oxidation of glucose. [Figure not available: see fulltext.]
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.
Crystal and molecular structure of N-(n-octyl)-6-deoxy-D-gluconamide: a novel packing of amphiphilic molecules
Herbst, Roswitha,Steiner, Thomas,Pfannemueller, Beate,Saenger, Wolfram
, p. 29 - 42 (1995)
N-(n-octyl)-6-deoxy-D-gluconamide crystallizes in the orthorhombic space group P212121, with a = 5.4524(5), b = 16.662(3), and c = 36.897(5) Angstroem.The structure was determined by X-ray diffraction and refined to R = 9.2percent.The asymmetric crystal unit contains two molecules (A, B) with significantly different conformations.In contrast to the crystal structures of the N-(n-alkyl)-D-gluconamide family, in which the molecules were found arranged in head-to-tail monolayers, molecules A and B form a complex motif with pairwise alternating orientations andinterdigitating antiparallel aliphatic chains.The two symmetry independent molecules form considerably different hydrogen bond patterns.Keywords: Alkyl-gluconamides; Amphiphilic molecules; Aliphatic chain packing; Crystal packing; Hydrogen bonding
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.
TEMPO-mediated oxidation of maltodextrins and D-glucose: Effect of pH on the selectivity and sequestering ability of the resulting polycarboxylates
Thaburet, Jean-Francois,Merbouh, Nabyl,Ibert, Mathias,Marsais, Francis,Queguiner, Guy
, p. 21 - 29 (2001)
Maltodextrins were oxidized to polyglucuronic acids with the ternary oxidation system: NaOCl-NaBr-2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO). The chemoselective oxidation at the primary alcohol groups was shown to be strongly pH dependent. Oxidation of
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.
Efficient and Bio-inspired Conversion of Cellulose to Formic Acid Catalyzed by Metalloporphyrins in Alkaline Solution
Liu, Qiang,Zhou, Doudou,Li, Zongxiang,Luo, Weiping,Guo, Cancheng
supporting information, p. 1063 - 1068 (2017/07/24)
A bio-inspired approach for efficient conversion of cellulose to formic acid (FA) was developed in an aqueous alkaline medium. Metalloporphyrins mimicking cytochrome P450 exhibit efficiently and selectively catalytic performance in catalytic conversion of cellulose. High yield of FA about 63.7% was obtained by using sulfonated iron(III) porphyrin as the catalyst and O2 as the oxidant. Iron(III)-peroxo species, TSPPFeIIIOO?, was involved to cleave the C-C bonds of gluconic acid to FA in this catalytic system. This approach used relatively high concentration of cellulose and ppm concentration of catalyst. This work may provide a bio-inspired route to efficient conversion of cellulose to FA.
