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Product Control and Insight into Conversion of C6 Aldose Toward C2, C4 and C6 Alditols in One-Pot Retro-Aldol Condensation and Hydrogenation Processes
Alcohols have a wide range of applicability, and their functions vary with the carbon numbers. C6 and C4 alditols are alternative of sweetener, as well as significant pharmaceutical and chemical intermediates, which are mainly obtained through the fermentation of microorganism currently. Similarly, as a bulk chemical, C2 alditol plays a decisive role in chemical synthesis. However, among them, few works have been focused on the chemical production of C4 alditol yet due to its difficult accumulation. In this paper, under a static and semi-flowing procedure, we have achieved the product control during the conversion of C6 aldose toward C6 alditol, C4 alditol and C2 alditol, respectively. About C4 alditol yield of 20 % and C4 plus C6 alditols yield of 60 % are acquired in the one-pot conversion via a cascade retro-aldol condensation and hydrogenation process. Furthermore, in the semi-flowing condition, the yield of ethylene glycol is up to 73 % thanks to its low instantaneous concentration.
Gao, Lou,Hou, Wenrong,Hui, Yingshuang,Tang, Yi,Zhan, Yulu,Zhang, Yahong
p. 560 - 566
(2021/06/25)

Selective and Scalable Synthesis of Sugar Alcohols by Homogeneous Asymmetric Hydrogenation of Unprotected Ketoses
Sugar alcohols are of great importance for the food industry and are promising building blocks for bio-based polymers. Industrially, they are produced by heterogeneous hydrogenation of sugars with H2, usually with none to low stereoselectivities. Now, we present a homogeneous system based on commercially available components, which not only increases the overall yield, but also allows a wide range of unprotected ketoses to be diastereoselectively hydrogenated. Furthermore, the system is reliable on a multi-gram scale allowing sugar alcohols to be isolated in large quantities at high atom economy.
Tindall, Daniel J.,Mader, Steffen,Kindler, Alois,Rominger, Frank,Hashmi, A. Stephen K.,Schaub, Thomas
supporting information
p. 721 - 725
(2020/10/19)

PROCESS FOR PREPARING ALKYLENE GLYCOL MIXTURE FROM A CARBOHYDRATE SOURCE WITH DECREASED SELECTIVITY FOR POLYOL SIDE PRODUCTS
The invention relates to a process for preparing a mixture of alkylene glycols (e.g. ethylene glycol and/or propylene glycol) from a carbohydrate source by catalytic conversion with hydrogen. More specifically, the catalytic hydrogenolysis process of the invention has a decreased selectivity for larger polyols like sorbitol and erythritol, which larger polyols are obtained generally as a side product in catalytic hydrogenolysis, when viewed in comparison to the selectivity for small alkylene glycols (like ethylene glycol and propylene glycol). This is achieved by ensuring the carbohydrate feed is rich in sucrose.
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(2021/08/27)

Photocatalytic Conversion of Xylose to Xylitol over Copper Doped Zinc Oxide Catalyst
Abstract: In the present investigation, photocatalytic conversion of xylose by Copper (Cu) doped Zinc oxide (ZnO) was investigated under Ultraviolet Light emitting diode (UVA-LED) illumination. Photocatalysts were synthesized successfully by chemical prec
Rohini,Hebbar, H. Umesh
p. 2583 - 2594
(2021/02/05)

Domino Hydroalkoxylation-[4+2]-Cycloaddition for Stereoselective Synthesis of 1,4-Heterocycle-Fused Chromenes: Rapid Access to the [6-6-7-6] Tetracyclic Core of Cytorhizhins B–D
A substrate dependent regio- and stereoselective domino hydroalkoxylation-formal-[4+2] cycloaddition is described for the facile synthesis of linear as well as spirocyclic 1,4-heterocycle-fused chromene ketals. Enantiospecific synthesis of oxazepino chromene derivatives was successfully carried out using chiral pool amino alkynols. The developed hydroalkoxylation cascade offered rapid access to the spirocyclic [6-6-7-6] tetracyclic core of cytorhizhins B–D with correct relative configuration.
Fartade, Dipak J.,Gharpure, Santosh J.,Nanda, Santosh K.,Vishwakarma, Dharmendra S.
supporting information
p. 6892 - 6897
(2020/01/25)

START-UP PROCESS FOR THE PRODUCTION OF GLYCOLS
The invention provides a start-up method for a process for the preparation of glycols from a starting material comprising one or more saccharides in the presence of hydrogen and a catalyst system comprising one or more retro-aldol catalysts comprising tungsten and one or more catalytic species suitable for hydrogenation in a reactor, said method comprising introducing the one or more retro-aldol catalysts to the reactor whilst also in the presence of one or more agents suitable to suppress tungsten precipitation.
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Paragraph 0056-0057

(2020/05/07)

Boron oxide modified bifunctional Cu/Al2O3 catalysts for the selective hydrogenolysis of glucose to 1,2-propanediol
A series of B2O3 modified Cu/Al2O3 catalysts were prepared for the hydrogenolysis of glucose. The catalysts were fully characterized by BET, ICP, N2O adsorptive decomposition, XRD, SEM, TG, H2-TPR, CO-FTIR, XPS, and NH3-TPD. The strong interaction between B2O3 and CuO could promote the dispersion of copper and inhibit the reduction of CuO, creating a proper mol ratio of Cuδ+/Cu0 for the hydrogenolysis of glucose to oxygen-containing chemicals. Furthermore, the doping of B2O3 also introduced more acid sites onto the CuB/Al2O3 catalysts, which is favorable for the cleavage of hydroxyl through dehydration. Therefore, the selective hydrogenolysis of glucose to 1,2-propanediol was dependent on the contribution of Cuδ+, Cu0, and acid sites. The catalytic activity and 1,2-propanediol selectivity were improved significantly by doping B2O3 into Cu/Al2O3. Among the catalysts, 1CuB/Al2O3 showed the highest selectivity for 1,2-propanediol, with the value of 49.5% at 96.6% conversion of glucose.
Liu, Chengwei,Shang, Yaning,Wang, Shen,Liu, Xin,Wang, Xianzhou,Gui, Jianzhou,Zhang, Chenghua,Zhu, Yulei,Li, Yongwang
(2020/02/18)

Effect of Cu addition to carbon-supported Ru catalysts on hydrogenation of alginic acid into sugar alcohols
The objective of this study was to investigate the effect of Cu addition to carbon supported Ru catalysts on the hydrogenation of macroalgae-derived alginic acid into sugar alcohols, mainly sorbitol and mannitol. Both geometric and electronic effects were determined based on results of H2-TPR, H2- or CO-chemisorption, and XPS analyses after Cu was added to Ru. The addition of Cu to Ru caused blocking of active Ru surface and electron transfer between Ru and Cu. The intimate interaction between Ru and Cu formed RuCu bimetallic clusters which expedited hydrogen spillover from Ru to Cu. The highest yield of target sugar alcohols of 47.4% was obtained when 5 wt% of Ru and 1 wt% of Cu supported on nitric acid-treated activated carbon reacted at 180 °C for 2 h. The RuCu bimetallic catalyst exhibited deactivation upon repeated reactions due to the carbon deposition on the catalyst.
Ban, Chunghyeon,Yang, Seungdo,Kim, Hyungjoo,Kim, Do Heui
p. 98 - 104
(2019/04/17)

Practical Cleavage of Acetals by Using an Odorless Thiol Immobilized on Silica
A practical, efficient and general method was developed for the deprotection of a variety of aromatic and aliphatic acetals to their corresponding catechol or diol derivatives using thiol immobilized on silica gel. This is an application for the well-known commercial solid-supported thiol (SiliaMetS Thiol). The procedure is mild and amenable to scale-up. It does not require inert atmosphere and clean conversions were observed. This method is applicable to substituted 1,3-benzodioxole and aliphatic acetals with different functionalities. It offers the advantage of a general route with high yield, which can be undertaken at ambient temperature.
de Léséleuc, Mylène,Kukor, Andrew,Abbott, Shaun D.,Zacharie, Boulos
p. 7389 - 7393
(2019/12/03)

CYCLIC COMPOUND
The present invention provides compounds having a Toll-like receptor 4 (TLR4) signaling inhibitory action useful as preventive and therapeutic drugs of autoimmune disease and/or inflammatory disease or diseases such as chemotherapy-induced peripheral neuropathy (CIPN), chemotherapy-induced neuropathic pain (CINP), liver injury, ischemia-reperfusion injury (IRI) and the like. The present invention relates to a compound represented by formula (I) and a salt thereof: (wherein, each symbol is explained in greater detail in the specification).
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Paragraph 0301

(2018/04/13)

Crystal structure of yeast xylose reductase in complex with a novel NADP-DTT adduct provides insights into substrate recognition and catalysis
Aldose reductases (ARs) belonging to the aldo-keto reductase (AKR) superfamily catalyze the conversion of carbonyl substrates into their respective alcohols. Here we report the crystal structures of the yeast Debaryomyces nepalensis xylose reductase (DnXR, AKR2B10) in the apo form and as a ternary complex with a novel NADP-DTT adduct. Xylose reductase, a key enzyme in the conversion of xylose to xylitol, has several industrial applications. The enzyme displayed the highest catalytic efficiency for l-threose (138 ± 7 mm?1·s?1) followed by d-erythrose (30 ± 3 mm?1·s?1). The crystal structure of the complex reveals a covalent linkage between the C4N atom of the nicotinamide ring of the cosubstrate and the S1 sulfur atom of DTT and provides the first structural evidence for a protein mediated NADP–low-molecular-mass thiol adduct. We hypothesize that the formation of the adduct is facilitated by an in-crystallo Michael addition of the DTT thiolate to the specific conformation of bound NADPH in the active site of DnXR. The interactions between DTT, a four-carbon sugar alcohol analog, and the enzyme are representative of a near-cognate product ternary complex and provide significant insights into the structural basis of aldose binding and specificity and the catalytic mechanism of ARs. Database: Structural data are available in the PDB under the accession numbers 5ZCI and 5ZCM.
Paidimuddala, Bhaskar,Mohapatra, Samar B.,Gummadi, Sathyanarayana N.,Manoj, Narayanan
p. 4445 - 4464
(2018/10/24)

Isolation, purification, characterization and antioxidant activity of polysaccharides from the stem barks of Acanthopanax leucorrhizus
A novel water-soluble polysaccharide (named ALP-1) was successfully isolated from the stem barks of Acanthopanax leucorrhizus by hot-water extraction, and further purified by Cellulose DEAE-52 and Sephadex G-100 chromatography. The structure of ALP-1 was characterized by HPLC, HPGPC, partial acid hydrolysis, periodate oxidation, Smith degradation, methylation, together with UV, IR and NMR spectral analysis. The antioxidant activities also were evaluated in vitro. Structural analysis revealed that ALP-1 was a homogeneous galactan with the average molecular weight of 169 kDa, composed of galactose, glucose, mannose and arabinose in a molar ratio of 6.1:2.1:1.1:1.0, owning a backbone structure of 1,6-linked α-D-Galp residues with some branches of α-D-Manp-(1 → 3)-α-L-Araf residues at O-3 and α-D-Galp residues at O-4 of 1,6-linked α-D-Galp. Antioxidant assay showed that ALP-1 exhibited strong DPPH[rad] and HO[rad] scavenging activities, as well as ferric-reducing antioxidant power. These results provide a scientific basis for the further use of polysaccharides from A. leucorrhizus.
Hu, Hao-Bin,Liang, Hai-Peng,Li, Hai-Ming,Yuan, Run-Nan,Sun, Jiao,Zhang, La-La,Han, Ming-Hu,Wu, Yun
p. 359 - 367
(2018/05/29)

Structure of an entangled heteropolysaccharide from Pholidota chinensis Lindl and its antioxidant and anti-cancer properties
A major polysaccharide PCP-I was isolated and purified from Pholidota chinensis Lindl. The physicochemical and structural properties of PCP-I were studied using high-performance size-exclusion chromatography (HPSEC), gas chromatography (GC), Fourier transform infrared spectroscopy (FTIR), periodate oxidation-smith degradation, methylation-GC–MS analysis, nuclear magnetic resonance (NMR) spectroscopy and transmission electron microscopy (TEM) analysis. PCP-I was homogeneous with molecular weight (Mw) of 249 kDa and composed of xylose and fucose at a molar ratio of 2.45:1. The repeating structural units of PCP-I were →3)-α-D-Xylp-(1→ and →4)-α-L-Fucp-(1→ the terminal fractions were T-D-GalAp, and TEM further revealed that PCP-I was the entangled microstructure which was composed of four non-branched single chains. Compared with Vitamin C (Vc) and 5 fluorine urine (5-Fu), PCP-I showed scavenging effects of superoxide (EC50 = 1.09 mg/mL) and hydroxyl (EC50 = 0.11 mg/mL) radicals equivalent to Vc, and PCP-I (IC50 = 69.54 μg/mL) also exhibited good anti-proliferation capability for human colon cancer cell line caco-2.
Luo, Dianhui,Wang, Zhaojing,Li, Zhiming,Yu, Xiao-qiang
p. 921 - 928
(2018/02/27)

Ordered Mesoporous NiCeAl Containing Catalysts for Hydrogenolysis of Sorbitol to Glycols
Cellulose-derived sorbitol is emerging as a feasible and renewable feedstock for the production of value-added chemicals. Highly active and stable catalyst is essential for sorbitol hydrogenolysis. Ordered mesoporous M–xNiyCeAl catalysts with different loadings of nickel and cerium species were successfully synthesized via one-pot evaporation-induced self-assembly strategy (EISA) and their catalytic performance were tested in the hydrogenolysis of sorbitol. The physical chemical properties for the catalysts were characterized by XRD, N2 physisorption, H2-TPR, H2 impulse chemisorption, ICP and TEM techniques. The results showed that the ordered mesopores with uniform pore sizes can be obtained and the Ni nanoparticles around 6 nm in size were homogeneously dispersed in the mesopore channels. A little amount of cerium species introduced would be beneficial to their textural properties resulting in higher Ni dispersion, metal area and smaller size of Ni nanoparticles. The M–10Ni2CeAl catalyst with Ni and Ce loading of 10.9 and 6.3 wt % shows better catalytic performance than other catalysts, and the yield of 1,2-PG and EG can reach 56.9% at 493 K and 6 MPa pressure for 8 h after repeating reactions for 12 times without obvious deterioration of physical and chemical properties. Ordered mesoporous M–NiCeAl catalysts are active and stable in sorbitol hydrogenolysis.
Zhou, Zhiwei,Zhang, Jiaqi,Qin, Juan,Li, Dong,Wu, Wenliang
p. 456 - 465
(2018/03/21)

Hydrogenolysis of sorbitol into valuable C3-C2 alcohols at low H2 pressure promoted by the heterogeneous Pd/Fe3O4 catalyst
The hydrogenolysis of sorbitol and various C5-C3 polyols (xylitol; erythritol; 1,2- 1,4- and 2,3-butandiol; 1,2-propandiol; glycerol) have been investigated at low molecular hydrogen pressure (5 bar) by using Pd/Fe3O4, as heterogeneous catalyst and water as the reaction medium. Catalytic experiments show that the carbon chain of polyols is initially shortened through dehydrogenation/decarbonylation and dehydrogenation/retro-aldol mechanisms followed by a series of cascade reactions that include dehydrogenation/decarbonylation and dehydration/hydrogenation processes. At 240 °C, sorbitol is fully converted into lower alcohols with ethanol being the main reaction product in liquid phase.
Gumina, Bianca,Mauriello, Francesco,Pietropaolo, Rosario,Galvagno, Signorino,Espro, Claudia
p. 152 - 160
(2018/02/17)

Xylitol Hydrogenolysis over Ruthenium-Based Catalysts: Effect of Alkaline Promoters and Basic Oxide-Modified Catalysts
The aqueous-phase hydrogenolysis of xylitol into glycols over Ru/C was performed in the presence and absence of a wide range of concentrations of Ca(OH)2 to investigate the reaction pathway. Without base, epimerization and cascade decarbonylation were the predominant reactions with high selectivities to C5 and C4 alditols and light alkanes at full conversion. Glycol production was obtained by the addition of Ca(OH)2 to promote the retro-aldol reaction. It competed with reactions without base and became the main reaction for a OH?/ xylitol molar ratio Rmol(OH/xylitol) of 0.13, and high selectivities to glycols (56 %) and glycerol (16 %) were observed. However, lactate was a byproduct at up to 27 % with a high base amount (Rmol(OH/xylitol)=0.68). Bifunctional Ru/metal oxide/C catalysts (metal: Zn, Sn, Mn, Sr, W) were synthesized and were able to cleave the C?C bond into glycols without a base promoter. The 3.1 wt %Ru/MnO(4.5 %)/C catalyst was the most active (220 h?1) with reasonable selectivity to glycols (22 %) and glycerol (10 %) and a low production of lactate (1 %). Nevertheless, metal oxide leaching of the catalyst was observed likely because of the production of traces of lactate.
Rivière, Maxime,Perret, Noémie,Cabiac, Amandine,Delcroix, Damien,Pinel, Catherine,Besson, Michèle
p. 2145 - 2159
(2017/06/28)

Hydrolytic hydrogenation of chitin to amino sugar alcohol
Chitin is the second most abundant biomass and characteristically contains nitrogen atoms in its monomer units. These favourable features promote chitin to be a potential resource for renewable organonitrogen compounds. 2-Acetamido-2-deoxysorbitol (ADS) is an attractive target in the derivatives of chitin, but the conversion of chitin to ADS has not been reported so far. In this work, we demonstrate the catalytic conversion of chitin to ADS using mechanocatalysis in the presence of H2SO4 and subsequent hydrolytic hydrogenation by H2SO4 and Ru/TiO2 without any purification process. Our study clarified that the yield of ADS is strongly influenced by the reaction temperature and pH. The hydrolysis favourably proceeds at high temperature and low pH (2.0), but the hydrogenation needs a low temperature and a specific pH of 3-4 to achieve high selectivity. Specifically, in the hydrogenation step, an acid causes various side-reactions of amide and hemiacetal groups especially in the presence of a Ru catalyst, whereas even a small amount of base drastically accelerates the retro-aldol reaction to form erythritol and N-acetylethanolamine. Therefore, a one-pot but two-step reaction is necessary to optimise both the hydrolysis and hydrogenation steps and maximise the overall yield of ADS up to 52%.
Kobayashi, Hirokazu,Techikawara, Kota,Fukuoka, Atsushi
p. 3350 - 3356
(2017/07/28)

Hormonemate Derivatives from Dothiora sp., an Endophytic Fungus
A search for cytotoxic agents from cultures of the endophytic fungus Dothiora sp., isolated from the endemic plant Launaea arborescens, led to the isolation of six new compounds structurally related to hormonemate, with moderate cytotoxic activity against different cancer cell lines. By using a bioassay-guided fractionation approach, hormonemates A-D (1-4), hormonemate (5), and hormonemates E (6) and F (7) were obtained from the acetone extract of this fungus. Their structures were determined using a combination of HRMS, ESI-qTOF-MS/MS, 1D and 2D NMR experiments, and chemical degradation. The cytotoxic activities of these compounds were evaluated by microdilution colorimetric assays against human breast adenocarcinoma (MCF-7), human liver cancer cells (HepG2), and pancreatic cancer cells (MiaPaca_2). Most of the compounds displayed cytotoxic activity against this panel.
Pérez-Bonilla, Mercedes,González-Menéndez, Víctor,Pérez-Victoria, Ignacio,De Pedro, Nuria,Martín, Jesús,Molero-Mesa, Joaquín,Casares-Porcel, Manuel,González-Tejero, María Reyes,Vicente, Francisca,Genilloud, Olga,Tormo, José R.,Reyes, Fernando
p. 845 - 853
(2017/05/05)

Influence of the Surface Chemistry of Multiwalled Carbon Nanotubes on the Selective Conversion of Cellulose into Sorbitol
Carbon nanotubes (CNT) were submitted to liquid-phase chemical treatments using HNO3 and subsequently to gas-phase thermal treatments to incorporate different sets of oxygenated groups on the surface. The modified CNT were used as supports for 0.4 wt % Ru in the direct conversion of ball-milled cellulose to sorbitol and high conversions were reached after 3 h at 205 °C. Ru supported on the original CNT, although less active, was the most selective catalyst for the one-pot process (70 % sorbitol selectivity after 2 h). Unlike the one-pot process, the support acidity greatly promoted the rate of cellulose hydrolysis (35 % increase after 2 h) and the glucose selectivity (12 % increase after 2 h). The rate of glucose hydrogenation was almost not affected by the support modification. However, the catalyst acidity improved the sorbitol selectivity from glucose. The support acidity was a central factor for the one-pot conversion of cellulose, as well as for the individual hydrolysis and hydrogenation steps, and the original CNT supported Ru catalyst was the most efficient and selective catalyst for the direct conversion of cellulose to sorbitol.
Ribeiro, Lucília S.,Delgado, Juan J.,de Melo órf?o, José J.,Ribeiro Pereira, M. Fernando
p. 888 - 896
(2017/03/13)

Influence of the functional groups of multiwalled carbon nanotubes on performance of Ru catalysts in sorbitol hydrogenolysis to glycols
Different functional groups (i.e. [sbnd]NH2, [sbnd]COOH, [sbnd]OH and nitrogen-doping) modified CNTs (denoted as AMCN, CMCN, HMCN and NMCN, respectively) supported ruthenium catalysts (Ru/AMCN, Ru/CMCN, Ru/HMCN and Ru/NMCN) were prepared by incipient wetness impregnation method. They were fully characterized by XRD, TG, Raman, XPS, TPD and TEM to elucidate the relationship between the physical property and their catalytic performance. TEM results shown that Ru particles were well dispersed on the surface for all the samples with the size of 1.48–1.99 nm. The effects of functional groups of carbon nanotubes (CNTs), nitrogen doping and base additive types on activity and selectivity of ethylene glycol (EG) and propylene glycol (1,2-PD) were investigated. In addition, the activity and final products distribution were much influenced by the properties of functional groups on CNTs and the type of metal cation of the base promoters, which probably participated in the reaction for accelerating a retro-aldol reaction for C[sbnd]C cleavage. Among the catalysts, Ru supported on AMCN exhibited the best catalytic activities and glycols selectivities than on MCN, CMCN, HMCN and NMCN.
Guo, Xingcui,Dong, Huihuan,Li, Bin,Dong, Linlin,Mu, Xindong,Chen, Xiufang
p. 79 - 87
(2016/12/09)

Effect of tungsten surface density of WO3-ZrO2 on its catalytic performance in hydrogenolysis of cellulose to ethylene glycol
One-pot hydrogenolysis of cellulose to ethylene glycol (EG) was carried out on WO3-based catalysts combined with Ru/C. To probe the active catalytic site for breaking the C-C bond of cellulose, a series of WO3-ZrO2 (WZr) catalysts were synthesized and systematically characterized with XRD, Raman, UV-Vis, H2-TPR, DRIFS and XPS techniques and N2 physisorption experiment. It was found that the WO3 crystallites became more easily reduced to W5+-OH species with increasing crystallite size or tungsten surface density of the WZr catalyst owing to the decrease of their absorption edge energy (AEE) originating from weakening their interaction with ZrO2 support. This, as a result, gave higher EG yield at higher tungsten surface density. The structure-activity relationship of the WZr catalyst reveals that the active catalytic site for cleaving the C2-C3 bond of the glucose molecule is the W5+-OH species.
Chai, Jiachun,Zhu, Shanhui,Cen, Youliang,Guo, Jing,Wang, Jianguo,Fan, Weibin
p. 8567 - 8574
(2017/02/10)

Selective C?O Hydrogenolysis of Erythritol over Supported Rh-ReOx Catalysts in the Aqueous Phase
Bimetallic Rh-ReOx (Re/Rh molar ratio 0.4–0.5) catalysts supported on TiO2 and ZrO2 were prepared by the successive impregnation of dried and calcined unreduced supported Rh catalysts. Their catalytic performances were evaluated in the hydrogenolysis of erythritol to butanetriols (BTO) and butanediols (BDO) in aqueous solution at 150–240 °C under 30–120 bar H2. The activity depended on the nature of the support, and the highest selectivity to BTO and BDO at 80 % conversion was 37 and 29 %, respectively, in the presence of 3.7 wt %Rh-3.5 wt %ReOx/ZrO2 at 200 °C under 120 bar. The characterization of the catalysts by CO chemisorption, TEM with energy-dispersive X-ray spectroscopy, thermogravimetric analysis with MS, and X-ray photoelectron spectroscopy suggests a different distribution and reducibility of Re species over the supported Rh nanoparticles, which depends on the support.
Said, Achraf,Da Silva Perez, Denilson,Perret, Noémie,Pinel, Catherine,Besson, Michèle
p. 2768 - 2783
(2017/07/28)

CYCLIC COMPOUNDS
The present invention provides compounds having a Toll-like receptor 4 (TLR4) signaling inhibitory action useful as preventive and therapeutic drugs of inflammatory disease and/or central nervous system disease or diseases such as chemotherapy-induced peripheral neuropathy (CIPN), chemotherapy-induced neuropathic pain (CINP), liver injury, ischemia-reperfusion injury (IRI) and the like. The present invention relates to a compound represented by formula (I) and a salt thereof: (wherein, each symbol is explained in greater detail in the specification).
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Paragraph 0701; 0702; 0703

(2016/11/24)

Kinetic insight into the effect of the catalytic functions on selective conversion of cellulose to polyols on carbon-supported WO3 and Ru catalysts
Efficient conversion of cellulose, the most abundant biomass on Earth, to chemicals in high yields remains a formidable challenge. Here, we report the marked change in the distribution of polyol products in the cellulose reaction on Ru/C and WO3/C, strongly depending on the competitive reactions of the glucose intermediate. WO3 crystallites not only promote, as a solid acid, the efficient hydrolysis of cellulose to glucose, but also catalyze the selective cleavage of the C-C bonds in glucose and other C6 sugar intermediates, leading to the formation of ethylene glycol and propylene glycol, in competition with the sugar hydrogenation to the corresponding C6 polyols (e.g. sorbitol) on Ru/C. The basic C support, behaving similar to other solid bases (i.e. MgO), catalyzes the isomerization of glucose into fructose, leading to the favored formation of propylene glycol instead of ethylene glycol. Such strong dependence of the product distribution on the catalytic functions is clarified by the kinetic analysis of the three competitive reactions of glucose, including its hydrogenation, isomerization and C-C bond cleavage. Importantly, such kinetic analysis can predict the maximum selectivity ratio of propylene glycol to ethylene glycol, which is 2.5, for example, at 478 K under the reaction conditions in this work, corresponding to a maximum yield of propylene glycol of ～71%. These understandings shed new insights into the selective conversion of cellulose, which provides guidance for the rational design of catalyst functions and tuning of reaction parameters towards the controllable synthesis of specific products from cellulose.
Liu, Yue,Liu, Haichao
p. 74 - 81
(2016/05/10)

Selective terminal C-C scission of C5-carbohydrates
The selective catalytic production of C4-tetritols (erythritol and threitol) from C5-sugars is an attractive route for the conversion of non-digestible sugars to C4-building blocks from agro residues. Here we show that an unprecedented high selectivity of 20-25% C4-tertritols can be achieved under mild conditions (138 °C, 6 bar H2, and 24 h) in the aqueous conversion of xylose over a 5 wt% Ru/C catalyst. A mechanistic study revealed that the dominant reaction mechanism for C5-sugar conversion involves a formal decarbonylation step leading to the initial formation of the desired C4-tetritols. Subsequently the formed C4-tetritols undergo further terminal C-C scissions to glycerol and ethylene glycol. Remarkably, potentially competing reactions like internal C-C chain scission (fragmentation) or hydrodeoxygenation (HDO) do not occur to any significant extent under the applied conditions.
Van Der Klis, Frits,Gootjes, Linda,Van Haveren, Jacco,Van Es, Daan S.,Bitter, Johannes H.
p. 3900 - 3909
(2015/07/15)

Effect of WOx on Bifunctional Pd-WOx/Al2O3 Catalysts for the Selective Hydrogenolysis of Glucose to 1,2-Propanediol
A series of Pd-WOx/Al2O3 catalysts with different contents of WOx were prepared by stepwise incipient wetness impregnations. The influence of WOx on the physicochemical properties of Pd-WOx/Al2O3 catalysts, as well as their catalytic performance for the hydrogenolysis of glucose to 1,2-propanediol (1,2-PDO), was investigated. At low surface W density (0.3-2.1 W nm-2), distorted isolated WOx and oligomeric WOx are present on the Pd-WOx/Al2O3 catalysts. Furthermore, isolated WO4 are the dominating species on the Pd-WOx(5%)/Al2O3 catalyst. When the W density increased to 3.1 W nm-2, polymeric WOx species are dominant on the Pd-WOx(30%)/Al2O3 catalyst. The Pd surface area decreased while the acid amount increased with increasing W density. Furthermore, increased Lewis acid sites are provided by isolated WO4 and oligomeric WOx species whereas increased Bronsted acid sites exist on polymeric WOx species. Lewis acid sites promote glucose isomerization to fructose, which is an intermediate in glucose hydrogenolysis to 1,2-PDO. Metal sites catalyze C=O hydrogenation and C-C hydrogenolysis, which avoid the coke formation on catalysts. 1,2-PDO selectivity is dependent on the synergy of Lewis acid and metal sites; however, Bronsted acid sites have no contribution to the 1,2-PDO production. Typically, the Pd-WOx(5%)/Al2O3 catalyst possessing the optimal balance of Lewis acid and the metal site shows a 1,2-PDO selectivity of 60.8% at a glucose conversion of 92.2% and has a lifetime of over 200 h.
Liu, Chengwei,Zhang, Chenghua,Sun, Sikai,Liu, Kangkai,Hao, Shunli,Xu, Jian,Zhu, Yulei,Li, Yongwang
p. 4612 - 4623
(2015/08/18)

Structure of Galactomannan from Seeds of Crotalaria alata
A galactomannan of MW 540 kDa was isolated from seeds of Crotalaria alata. Chemical and spectral (PMR and 13C NMR) methods established that the main chain of the galactomannan consisted of β-1,4-mannan with α-1,6-D-galactopyranose side chains.
Kodiralieva,Shashkov,Rakhmanberdyeva
p. 405 - 408
(2015/06/16)

Catalytic oxidation of cellobiose over TiO2 supported gold-based bimetallic nanoparticles
A series of Au-M (M = Cu, Co, Ru and Pd) bimetallic catalysts were supported on TiO2via a deposition-precipitation (DP) method, using urea as a precipitating agent. The resulting catalysts were employed in the catalytic oxidation of cellobiose to gluconic acid and the properties of these catalysts were carefully examined using various characterization techniques. Cu-Au/TiO2 and Ru-Au/TiO2 catalysts demonstrated excellent catalytic activities in the oxidation of cellobiose to gluconic acid, though with contrasting reaction mechanisms. Complete conversion of cellobiose (100%) with a gluconic acid selectivity of 88.5% at 145 °C within 3 h was observed for reactions performed over Cu-Au/TiO2; whereas, a conversion of 98.3% with a gluconic acid selectivity of 86. 9% at 145°C within 9 h was observed for reactions performed over Ru-Au/TiO2. A reaction pathway was proposed based on the distribution of reaction products and kinetic data. It is suggested that cellobiose is converted to cellobionic acid (4-O-beta-d-glucopyranosyl-d-gluconic acid) and then gluconic acid is formed through the cleavage of the β-1,4 glycosidic bond in cellobionic acid over Cu-Au/TiO2 catalysts. On the other hand, for reactions over the Ru-Au/TiO2 catalyst, glucose was observed as the reaction intermediate and gluconic acid was formed as a result of glucose oxidation. For reactions over Co-Au/TiO2 and Pd-Au/TiO2 catalysts, fructose was observed as the reaction intermediate, along with small amounts of glucose. Co and Pd remarkably promoted the successive retro-aldol condensation reactions of fructose to glycolic acid, instead of the selective oxidation to gluconic acid. This journal is
Amaniampong, Prince Nana,Jia, Xinli,Wang, Bo,Mushrif, Samir H.,Borgna, Armando,Yang, Yanhui
p. 2393 - 2405
(2015/04/14)

From microcrystalline cellulose to hard- and softwood-based feedstocks: Their hydrogenolysis to polyols over a highly efficient ruthenium-tungsten catalyst
The utilization of cellulose and its integration in a biorefinery concept is essential even in the near future due to the growing global shortage of crude oil. Here, we report the catalyzed one-pot hydrogenolysis of cellulosic materials to valuable bio-derived molecules, especially polyols (e.g. ethylene glycol). We demonstrate how a very promising bifunctional catalyst, Ru/W/AC, converted not only 100% of microcrystalline cellulose to polyols in repeated experiments with a maximum yield of 84% and an ethylene glycol productivity of 3.7 g (gcatalyst h)-1, but also pine-, birch-, and eucalyptus-derived materials. Moreover, we systematically investigated the problem of catalyst stability with time by studying the changes in both the catalyst structure and the liquid phase, which have often been overlooked when biomass is converted to fuels and chemicals. Control of the active sites for the conversion of cellulosic feedstocks coupled with reaction engineering and strategies to prevent catalyst deactivation, is a prerequisite to understanding how high yields of platform chemicals can be achieved.
Fabi?ovicová, Katarína,Lucas, Martin,Claus, Peter
p. 3075 - 3083
(2015/05/27)

A method for producing isomaltooligo hydrogenolytic
PROBLEM TO BE SOLVED: To provide a method for producing a hydrogenolysis product of erythritol, with which the erythritol is efficiently subjected to hydrogenolysis in mild conditions to provide butane-mono, di or triol.SOLUTION: The method for producing the hydrogenolysis product of erythritol includes a process of reacting the erythritol and hydrogen in the presence of a catalyst to prepare at least one of compound selected from butane-mono, di and triol, wherein, as the catalyst, a catalyst prepared by depositing at least one of metal component selected from a group comprising iridium, platinum, rhodium, cobalt, palladium and nickel is used.
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Paragraph 0079-0081

(2017/01/02)

Unravelling the Ru-Catalyzed Hydrogenolysis of Biomass-Based Polyols under Neutral and Acidic Conditions
The aqueous Ru/C-catalyzed hydrogenolysis of biomass-based polyols such as erythritol, xylitol, sorbitol, and cellobitol is studied under neutral and acidic conditions. For the first time, the complete product spectrum of C2-C6 polyols is identified and, based on a thorough analysis of the reaction mixtures, a comprehensive reaction mechanism is proposed, which consists of (de)hydrogenation, epimerization, decarbonylation, and deoxygenation reactions. The data reveal that the Ru-catalyzed deoxygenation reaction is highly selective for the cleavage of terminal hydroxyl groups. Changing from neutral to acidic conditions suppresses decarbonylation, consequently increasing the selectivity towards deoxygenation.
Hausoul, Peter J. C.,Negahdar, Leila,Schute, Kai,Palkovits, Regina
p. 3323 - 3330
(2015/10/19)

Conversion of glucose and sorbitol in the presence of Ru/C and Pt/C catalysts
The conversion of glucose and sorbitol in the presence of Ru and Pt catalysts supported on carbon was carried out at different pressure and temperature conditions, using a batch and a semi-batch reactor. Attempts were made to improve the selectivity of glycols and alcohols (ethanol), introducing a promoter and inhibiter of the hydrogenolysis in the reactant mixture. On the basis of these results, which confirm the higher activity of Ru with respect to Pt, and the important role of an inhibitor like sulphur, the mechanism driving these reactions and the promising thermocatalytic conditions are clearer. This journal is
Tronci, Stefania,Pittau, Barbara
p. 23086 - 23093
(2015/06/02)

A facile synthesis of vicinal cis-diols from olefins catalyzed by in situ generated MnxOy nanoaggregates
A novel protocol for the practical and green synthesis of vicinal cis-diols from 10.0 mmol olefins by using 5.0 mmol KMnO4 as oxidant and 30.0 mmol H2O2 as co-oxidant is reported. The presented procedure is easy to carry out and enables the direct transformation of linear and cyclic alkenes to the corresponding vicinal cis-diols. The synthesis of vicinal cis-diols by dihydroxylation of olefins with a KMnO4/H2O2 system was catalyzed by in situ generated MnxOy nanoaggregates. The use of H2O2 as a co-oxidant is the key for the protocol to synthesize vicinal cis-diols in high yields, because it assists the oxidation of MnxOy nanoaggregates, which have an active role in the oxidation reaction medium.
Dalmizrak, Di?dem,G?ksu, Haydar,Gültekin, Mehmet Serdar
p. 20751 - 20755
(2015/03/18)

Direct conversion of cellulose into acetol on bimetallic Ni-SnO x/Al2O3 catalysts
The direct conversion of cellulose into acetol was studied on SnO x-modified Ni/Al2O3 catalysts with different Sn/Ni atomic ratios in the range of 0-2.0. The selectivity to acetol strongly depended on the Sn/Ni ratios, which reached the highest value of 53.9% at the ratio of 0.5, compared at similar cellulose conversions (～20%). On Ni-SnOx/Al2O3 (Sn/Ni = 0.5), cellulose, glucose and fructose converted to acetol in high yields of approximately 35%, 53% and 73%, respectively, at 210 °C and 6 MPa H2. The effects of the Sn/Ni ratios on the acetol selectivity appear to be related to their effects on the hydrogenation activity of the Ni-SnOx/Al2O3 catalysts that decreased with increase of the Sn/Ni ratios, and to the relative rate between the hydrogenation of C6 sugar intermediates (e.g. glucose and fructose) and their degradation intermediates (e.g. glyceraldeyde and dihydroxyacetone) involved in the cellulose reaction on the Ni particles and the isomerization of glucose to fructose and their CC bond cleavage by retro-aldol condensation on the SnOx domains. Comparison of SnO x with CeOx, ZnOx and AlOx supported on Al2O3 with different basicity suggested that the larger concentration of stronger basic sites on SnOx facilitated the isomerizaiton of glucose to fructose and its subsequent CC bond cleavage. These results and their understanding provide guidance for improving the acetol production from cellulose by tuning the catalytic functions required for the involved reactions of hydrogenation on the metal surfaces, and isomerization and CC bond cleavage on the basic sites.
Deng, Tianyin,Liu, Haichao
p. 66 - 73
(2014/06/09)

Conversion of sugars to ethylene glycol with nickel tungsten carbide in a fed-batch reactor: High productivity and reaction network elucidation
Bifunctional nickel tungsten carbide catalysis was used for the conversion of aqueous sugar solutions into short-chain polyols such as ethylene glycol. It is shown that very concentrated sugar solutions, viz. up to 0.2 kg L -1, can be converted without loss of ethylene glycol selectivity by gradually feeding the sugar solution. Detailed investigation of the reaction network shows that, under the applied reaction conditions, glucose is converted via a retro-aldol reaction into glycol aldehyde, which is further transformed into ethylene glycol by hydrogenation. The main byproducts are sorbitol, erythritol, glycerol and 1,2-propanediol. They are formed through a series of unwanted side reactions including hydrogenation, isomerisation, hydrogenolysis and dehydration. Hydrogenolysis of sorbitol is only a minor source of ethylene glycol. To assess the relevance of the fed-batch system in biomass conversions, both the influence of the catalyst composition and the reactor setup parameters like temperature, pressure and glucose addition rate were optimized, culminating in ethylene glycol yields up to 66% and separately, volume productivities of nearly 300 gEG L-1 h-1.
Ooms, Roselinde,Dusselier, Michiel,Geboers, Jan A.,Op De Beeck, Beau,Verhaeven, Rick,Gobechiya, Elena,Martens, Johan A.,Redl, Andreas,Sels, Bert F.
p. 695 - 707
(2014/02/14)

Exploring the reaction conditions for Ru/C catalyzed selective hydrogenolysis of xylitol alkaline aqueous solutions to glycols in a trickle-bed reactor
The hydrogenolysis of an alkaline aqueous solution of xylitol to mainly ethylene- and propylene-glycols was studied over a Ru/C catalyst in a high pressure fixed-bed reactor run in the trickle-bed mode with co-current downflow of liquid feed and hydrogen. The effects of reaction parameters including H 2 pressure (40-80 bar), temperature (190-200 °C) and pH values (NaOH/xylitol molar ratio in the range 0.1-0.2, pH 9-12) and residence time have been explored to increase the selectivity of this reaction to the desired ethyleneglycol product. The activity and final products distribution were much influenced by the hydrogen pressure. An optimum to afford a high conversion and a high selectivity to ethyleneglycol at different space times was found at 60 bar. The effects observed are in agreement with the reaction pathways previously proposed and the relative reaction rates of the dehydrogenation/hydrogenation and base-catalyzed reactions of the intermediates are affected by the hydrogen pressure and the concentration of the alkaline promoter.
Auneau, Florian,Berchu, Maeva,Aubert, Guillaume,Pinel, Catherine,Besson, Michèle,Todaro, Daniela,Bernardi, Marco,Ponsetti, Tiziano,Di Felice, Renzo
p. 100 - 106
(2014/07/07)

Titania-supported gold nanoparticles as efficient catalysts for the oxidation of cellobiose to organic acids in aqueous medium
Titania-supported gold nanoparticles were prepared by using the deposition-precipitation method, followed by reduction under a hydrogen flow. The catalytic activity of these as-prepared catalysts was explored in the oxidation of cellobiose to gluconic acid with molecular oxygen, and the properties of these catalysts were examined by using XRD, TEM, temperature-programmed desorption of NH3, energy-dispersive X-ray spectroscopy, UV/Vis, and X-ray photoemission spectroscopy (XPS). The catalyst sample reduced at high temperature demonstrated an excellent catalytic activity in the oxidation of cellobiose. The characterization results revealed the strong metal-support interaction between the gold nanoparticles and titania support. Hydrogen reduction at higher temperatures (usually >600C) plays a vital role in affording a unique interface between gold nanoparticles and titania support surfaces, which thus improves the catalytic activity of gold/titania by fine-tuning both the electronic and structural properties of the gold nanoparticles and titania support.
Amaniampong, Prince N.,Li, Kaixin,Jia, Xinli,Wang, Bo,Borgna, Armando,Yang, Yanhui
p. 2105 - 2114
(2014/08/05)

Selective hydrogenolysis of biomass-derived xylitol to ethylene glycol and propylene glycol on Ni/C and basic oxide-promoted Ni/C catalysts
The selective hydrogenolysis of xylitol to ethylene glycol and propylene glycol was examined on Ni/C catalysts in the presence of solid bases, e.g. Ca(OH)2 and CeO2, physically mixed with or co-supported with Ni on C. Compared with Ru/C, the Ni/C catalysts were more selective to the two target glycols under identical conditions, apparently as a result of their lower hydrogenation activity and consequently favored the CC cleavage of xylose intermediate by the base catalyst over its competitive hydrogenation on the Ni particles. Noticeably, the presence of the solid bases rendered the Ni particles resistant to leaching and sintering, and thus stable in the xylitol hydrogenolysis. Supporting the solid bases, especially CeO2 and CaO, with the Ni particles on C led not only to a reduction in the amount of solid bases required, but also efficient formation of the two glycols with negligible lactic acid. For instance, on Ni-CaO/C (at a CaO/Ni molar ratio of 0.66), the combined selectivity to ethylene glycol and propylene glycol, together with glycerol, reached 69.5% at nearly 100% xylitol conversion at 473 K, 4.0 MPa H2. These features of the basic oxide-promoted Ni catalysts show their promising advantages over the noble Ru catalysts, upon optimization of their compositions and structures, and the reaction parameters, for the efficient hydrogenolysis of xylitol and other lignocellulose-derived polyols to produce the two target glycols.
Sun, Jiying,Liu, Haichao
p. 75 - 82
(2014/07/07)

Acid-catalyzed reactions of epoxides for atmospheric nanoparticle growth
Although new particle formation accounts for about 50% of the global aerosol production in the troposphere, the chemical species and mechanism responsible for the growth of freshly nucleated nanoparticles remain largely uncertain. Here we show large size
Xu, Wen,Gomez-Hernandez, Mario,Guo, Song,Secrest, Jeremiah,Marrero-Ortiz, Wilmarie,Zhang, Annie L.,Zhang, Renyi
supporting information
p. 15477 - 15480
(2015/02/18)

Rabbit 3-hydroxyhexobarbital dehydrogenase is a NADPH-preferring reductase with broad substrate specificity for ketosteroids, prostaglandin D2, and other endogenous and xenobiotic carbonyl compounds
3-Hydroxyhexobarbital dehydrogenase (3HBD) catalyzes NAD(P) +-linked oxidation of 3-hydroxyhexobarbital into 3-oxohexobarbital. The enzyme has been thought to act as a dehydrogenase for xenobiotic alcohols and some hydroxysteroids, but its physiological function remains unknown. We have purified rabbit 3HBD, isolated its cDNA, and examined its specificity for coenzymes and substrates, reaction directionality and tissue distribution. 3HBD is a member (AKR1C29) of the aldo-keto reductase (AKR) superfamily, and exhibited high preference for NADP(H) over NAD(H) at a physiological pH of 7.4. In the NADPH-linked reduction, 3HBD showed broad substrate specificity for a variety of quinones, ketones and aldehydes, including 3-, 17- and 20-ketosteroids and prostaglandin D2, which were converted to 3α-, 17β- and 20α-hydroxysteroids and 9α,11β- prostaglandin F2, respectively. Especially, α-diketones (such as isatin and diacetyl) and lipid peroxidation-derived aldehydes (such as 4-oxo- and 4-hydroxy-2-nonenals) were excellent substrates showing low Km values (0.1-5.9 μM). In 3HBD-overexpressed cells, 3-oxohexobarbital and 5β-androstan-3α-ol-17-one were metabolized into 3-hydroxyhexobarbital and 5β-androstane-3α,17β-diol, respectively, but the reverse reactions did not proceed. The overexpression of the enzyme in the cells decreased the cytotoxicity of 4-oxo-2-nonenal. The mRNA for 3HBD was ubiquitously expressed in rabbit tissues. The results suggest that 3HBD is an NADPH-preferring reductase, and plays roles in the metabolisms of steroids, prostaglandin D2, carbohydrates and xenobiotics, as well as a defense system, protecting against reactive carbonyl compounds.
Endo, Satoshi,Matsunaga, Toshiyuki,Matsumoto, Atsuko,Arai, Yuki,Ohno, Satoshi,El-Kabbani, Ossama,Tajima, Kazuo,Bunai, Yasuo,Yamano, Shigeru,Hara, Akira,Kitade, Yukio
p. 1366 - 1375
(2013/11/19)

Catalytic conversion of cellulose to ethylene glycol over a low-cost binary catalyst of Raney Ni and tungstic acid
Following our previous report on the selective transformation of cellulose to ethylene glycol (EG) over a binary catalyst composed of tungstic acid and Ru/C, we herein report a new lowcost but more effective binary catalyst by using Raney nickel in place of Ru/C (Raney Ni+H2WO4). In addition to tungstic acid, other W compounds were also investigated in combination with Raney Ni. The results showed that the EG yield depended on the W compound: H4SiW12O40H3PW 12O40WO3H2WO4, but all the investigated W compounds were selective towards EG. Moreover, both WO 3 and H2WO4 were dissolved partially under the reaction conditions and transformed into HxWO3 which is the genuinely active species for the C-C bond breakage of cellulose. This result further confirmed that the reaction that involves the selective breakage of the C-C bonds of cellulose with W species is homogenous. Among various binary catalysts, the combination of Raney Ni and H2WO4 gave the highest yield of EG (65 %), which could be attributed to the high activity of Raney Ni for hydrogenation and its inertness for the further degradation of EG. Moreover, Raney Ni+H2WO4 showed good reusability; it could be reused at least 17 times without any decay in the EG yield, which shows its great potential for industrial applications.
Tai, Zhijun,Zhang, Junying,Wang, Aiqin,Pang, Jifeng,Zheng, Mingyuan,Zhang, Tao
p. 652 - 658
(2013/07/27)

Promoting effect of SnOx on selective conversion of cellulose to polyols over bimetallic Pt-SnOx/Al2O3 catalysts
Cellulose is the most abundant source of biomass in nature, and its selective conversion into polyols provides a viable route towards the sustainable synthesis of fuels and chemicals. Here, we report the marked change in the distribution of polyols in the cellulose reaction with the Sn/Pt atomic ratios in a wide range of 0.1-3.8 on the SnOx-modified Pt/Al 2O3 catalysts. Such a change was found to be closely related to the effects of the Sn/Pt ratios on the activity for the hydrogenation of glucose and other C6 sugar intermediates involved in the cellulose reaction as well as to the notable activity of the segregated SnO x species for the selective degradation of the sugar intermediates on the Pt-SnOx/Al2O3 catalysts. At lower Sn/Pt ratios of 0.1-1.0, there existed electron transfer from the SnOx species to the Pt sites and strong interaction between the catalysts, as characterized by temperature-programmed reduction in H2 and infrared spectroscopy for CO adsorption, which led to their superior hydrogenation activity (per exposed Pt atom), and in-parallel higher selectivity to hexitols (e.g. sorbitol) in the cellulose reaction, as compared to Pt/Al 2O3. The hexitol selectivity reached the greatest value of 82.7% at the Sn/Pt ratio of 0.5, nearly two times that of Pt/Al 2O3 at similar cellulose conversions (～20%). As the Sn/Pt ratios exceeded 1.5, the Pt-SnOx/Al2O3 catalysts exhibited inferior hydrogenation activity (per exposed Pt atom), due to the formation of the crystalline Pt-Sn alloy, which led to the preferential conversion of cellulose to C2 and especially C3 products (e.g. acetol) over hexitols, most likely involving the isomerization of glucose to fructose and retro-aldol condensation of these sugars on the segregated SnOx species, apparently in the form of Sn(OH)2. These findings clearly demonstrate the feasibility for rational control of the cellulose conversion into the target polyols (e.g. acetol or propylene glycol), for example, by the design of efficient catalysts based on the catalytic functions of the SnOx species with tunable hydrogenation activity.
Deng, Tianyin,Liu, Haichao
p. 116 - 124
(2013/02/26)

Probing the ruthenium-catalyzed higher polyol hydrogenolysis reaction through the use of stereoisomers
Nine polyol stereoisomers ranging from three to six carbons in length were reacted under hydrogenolysis conditions (205-240°C, 100 bar H2) over a Ru-C catalyst to better understand the reaction mechanism. Previous reports have postulated the retro-aldol mechanism as the main pathway leading to C-C scission. However, the retro-aldol mechanism was insufficient in explaining the product distribution of tetritols from pentitols, while the decarbonylation mechanism could explain the selectivity results of terminal C-C scission. Retro-aldol scission of internal C-C bonds was confirmed to occur by the tetritol product distribution from hexitols. Therefore, the presence or role of 3-keto and 4-keto intermediates had a negligible effect on the C-C hydrogenolysis of polyols when compared to aldehyde intermediates. The reaction rates of the polyols depended on the configuration of the polyol stereoisomers. The reactivity of the stereoisomers was correlated to the presence of erythro sequences of hydroxyl groups and was independent of the carbon chain length. The Royal Society of Chemistry.
Deutsch, Keenan L.,Lahr, Daniel G.,Shanks, Brent H.
p. 1635 - 1642
(2013/02/23)

COMPOSITIONS CONTAINING SUCRALOSE AND APPLICATION THEREOF
Novel utilization of sucralose which is a high intense sweetener. Compositions containing sucralose including: sweetening compositions having excellent sweetness qualities based on the characteristics of sucralose; foods with a masked unpleasant smell and unpleasant taste; performance food compositions (viscous food compositions, gel food compositions, emulsified food compositions); foods with improved flavors; preservatives and foods with improved quality of taste; and flavor compositions with improved flavors. Novel utilization of sucralose as a sweetener improver, a masking agent for unpleasant smell/unpleasant taste, a flavor improver, a function improver (viscosity, gelling properties, emulsification properties), a taste characteristic improver, and a flavor improver/enhancer.
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(2012/05/21)

Asymmetric organocatalytic formation of protected and unprotected tetroses under potentially prebiotic conditions
Esters of proteinogenic amino acids efficiently catalyse the formation of erythrose and threose under potentially prebiotic conditions in the highest yields and enantioselectivities yet reported. Remarkably while esters of (l)-proline yield (l)-tetroses, esters of (l)-leucine, (l)-alanine and (l)-valine generate (d)-tetroses, offering the potential to account for the link between natural (l)-amino acids and natural (d)-sugars. The effect of pH and NaCl on the yields and enantioselectivities was also investigated and was shown to be significant, with the optimal enantioselectivities occurring at pH 7.
Burroughs, Laurence,Clarke, Paul A.,Forintos, Henrietta,Gilks, James A. R.,Hayes, Christopher J.,Vale, Matthew E.,Wade, William,Zbytniewski, Myriam
experimental part
p. 1565 - 1570
(2012/04/05)

Nitrone formation in phosphate buffer and aqueous solutions: Novel chemistry inspired by a natural product
Nitrones are formed from the reaction of aspergillusol A (1) and a ketone/aldehyde in phosphate buffer and aqueous solutions with pH ranges of 6.8-8.6, resembling physiological conditions. The reaction of 1 with 1-substituted cyclohexanones gave the (1′S,2′R)-isomer, diastereoselectively.
Pansanit, Acharavadee,Ingavat, Nattha,Aree, Thammarat,Mahidol, Chulabhorn,Ruchirawat, Somsak,Kittakoop, Prasat
supporting information; experimental part
p. 2129 - 2131
(2012/07/14)

Hydrogenolysis of sorbitol over Ni and Pt loaded on NaY
The hydrogenolysis of sorbitol (15% aqueous solution) was carried out at 60 bar pressure at 220 °C in a stirred batch reactor using Ni-NaY (2, 4, 6 wt.% Ni) with and without added Pt(1 wt.%). 1,2-Propanediol was the major product over Ni-NaY and glycerol was the main product over Pt(1 wt.%)-NaY. The addition of 1 wt.% Pt to the Ni-catalysts had only a marginal effect on conversion and selectivity of the catalysts. Addition of Ca(OH)2 as the promoter to both Ni and Pt catalysts increased the conversion significantly without any significant effect on selectivity.
Banu,Sivasanker,Sankaranarayanan,Venuvanalingam
experimental part
p. 673 - 677
(2012/01/12)

Heteropoly acids as efficient acid catalysts in the one-step conversion of cellulose to sugar alcohols
Cellulose and even spruce can be converted efficiently into valuable platform chemicals via combined hydrolysis and hydrogenation in the aqueous phase. Thereby, heteropoly acids together with supported ruthenium catalysts show not only high activity but also remarkable selectivity to sugar alcohols reaching up to 81% yield of C4 to C6 sugar alcohols in only 7 h at 160 °C.
Palkovits, Regina,Tajvidi, Kameh,Ruppert, Agnieszka M.,Procelewska, Joanna
supporting information; experimental part
p. 576 - 578
(2011/03/17)

Selective hydrogenolysis of biomass-derived xylitol to ethylene glycol and propylene glycol on supported Ru catalysts
The selective hydrogenolysis of biomass-derived xylitol to ethylene glycol and propylene glycol was carried out on different catalysts in the presence of Ca(OH)2. The catalysts included Ru supported on activated carbon (C) and, for comparison, on metal oxides, Al2O3, TiO 2, ZrO2 and Mg2AlOx as well as C-supported other noble metals, Rh, Pd and Pt, with similar particle sizes (1.6-2.0 nm). The kinetic effects of H2 pressures (0-10 MPa), temperatures (433-513 K) and solid bases including Ca(OH)2, Mg(OH)2 and CaCO3 were examined on Ru/C. Ru/C exhibited superior activities and glycol selectivities than Ru on TiO2, ZrO2, Al2O3 and Mg2AlOx, and Pt was found to be the most active metal. Such effects of the metals and supports are attributed apparently to their different dehydrogenation/ hydrogenation activities and surface acid-basicities, which consequently influenced the xylitol reaction pathways. The large dependencies of the activities and selectivities on the H2 pressures, reaction temperatures, and pH values showed their effects on the relative rates for the hydrogenation and base-catalyzed reactions involved in xylitol hydrogenolysis, reflecting the bifunctional nature of the xylitol reaction pathways. These results led to the proposition that xylitol hydrogenolysis to ethylene glycol and propylene glycol apparently involves kinetically relevant dehydrogenation of xylitol to xylose on the metal surfaces, and subsequent base-catalyzed retro-aldol condensation of xylose to form glycolaldehyde and glyceraldehyde, followed by direct glycolaldehyde hydrogenation to ethylene glycol and by sequential glyceraldehyde dehydration and hydrogenation to propylene glycol. Clearly, the relative rates between the hydrogenation of the aldehyde intermediates and their competitive reactions with the bases dictate the selectivities to the two glycols. This study provides directions towards efficient synthesis of the two glycols from not only xylitol, but also other lignocellulose-derived polyols, which can be achieved, for example, by optimizing the reaction parameters, as already shown by the observed effects of the catalysts, pH values, and H2 pressures.
Sun, Jiying,Liu, Haichao
experimental part
p. 135 - 142
(2011/04/15)

Efficient asymmetric organocatalytic formation of erythrose and threose under aqueous conditions
Esters of proteinogenic amino acids efficiently catalyse the formation of erythrose and threose under aqueous conditions in the highest yields and enantioselectivities yet reported. Remarkably while esters of (l)-proline yield (l)-carbohydrates, esters of (l)-leucine and (l)-alanine generate (d)-carbohydrates, offering the potential to account for the prebiotic link between natural (l)-amino acids and natural (d)-sugars.
Burroughs, Laurence,Vale, Matthew E.,Gilks, James A. R.,Forintos, Henrietta,Hayes, Christopher J.,Clarke, Paul A.
supporting information; experimental part
p. 4776 - 4778
(2010/09/05)