- Metal oxide-triazole hybrids as heterogeneous or reaction-induced self-separating catalysts
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The hybrid metal oxide-triazole materials [MoO3(trz)0.5] (1) and [W2O6(trz)] (2) (trz?=?1,2,4-triazole) have been hydrothermally synthesized and characterized by different techniques (TGA, SEM, 1H and 13C MAS NMR, FT-IR spectroscopy, and structure determination by Rietveld analysis of high resolution synchrotron powder XRD data). Materials 1 and 2 display distinct behaviors when applied as catalysts for oxidation reactions with alcohol, aldehyde, olefin and sulfide substrates, and are more effective with hydrogen peroxide as the oxidant than with tert-butylhydroperoxide. The MoVI hybrid 1 transforms into soluble active species during cis-cyclooctene epoxidation with H2O2. When consumption of H2O2 reaches completion, spontaneous reassembly of the 2-dimensional molybdenum oxide network of 1 takes place and the hybrid precipitates as a microcrystalline solid that can be easily separated and recycled. Reaction-induced self-separation behavior occurs with 1, H2O2 and other substrates such as methyl oleate and methylphenylsulfide. The WVI hybrid 2 behaves differently, preserving its structural features throughout the heterogeneous catalytic process.
- Amarante, Tatiana R.,Neves, Patrícia,Valente, Anabela A.,Paz, Filipe A. Almeida,Pillinger, Martyn,Gon?alves, Isabel S.
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- Plasticizer and surfactant formation from food-waste- and algal biomass-derived lipids
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The potential of lipids derived from food-waste and algal biomass (produced from food-waste hydrolysate) for the formation of plasticizers and surfactants is investigated herein. Plasticizers were formed by epoxidation of double bonds of methylated unsaturated fatty acids with in situ generated peroxoformic acid. Assuming that all unsaturated fatty acids are convertible, 0.35 and 0.40 g of plasticizer can be obtained from 1 g of crude algae- or food-waste-derived lipids, respectively. Surfactants were formed by transesterification of saturated and epoxidized fatty acid methyl esters (FAMEs) with polyglycerol. The addition of polyglycerol would result in a complete conversion of saturated and epoxidized FAMEs to fatty acid polyglycerol esters. This study successfully demonstrates the conversion of food-waste into value-added chemicals using simple and conventional chemical reactions.
- Pleissner, Daniel,Lau, Kin Yan,Zhang, Chengwu,Lin, Carol Sze Ki
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- Biobased Aldehydes from Fatty Epoxides through Thermal Cleavage of β-Hydroxy Hydroperoxides**
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The ring-opening of epoxidized methyl oleate by aqueous H2O2 has been studied using tungsten and molybdenum catalysts to form the corresponding fatty β-hydroxy hydroperoxides. It was found that tungstic acid and phosphotungstic acid gave the highest selectivities (92–93 %) towards the formation of the desired products, thus limiting the formation of the corresponding fatty 1,2-diols. The optimized conditions were applied to a range of fatty epoxides to give the corresponding fatty β-hydroxy hydroperoxides with 30–80 % isolated yields (8 examples). These species were fully characterized by 1H and 13C NMR spectroscopy and HPLC-HRMS, and their stability was studied by differential scanning calorimetry. The thermal cleavage of the β-hydroxy hydroperoxide derived from methyl oleate was studied both in batch and flow conditions. It was found that the thermal cleavage in flow conditions gave the highest selectivity towards the formation of aldehydes with limited amounts of byproducts. The aldehydes were both formed with 68 % GC yield, and nonanal and methyl 9-oxononanoate were isolated with 57 and 55 % yield, respectively. Advantageously, the overall process does not require large excess of H2O2 and only generates water as a byproduct.
- De Dios Miguel, Thomas,Duc Vu, Nam,Lemaire, Marc,Duguet, Nicolas
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- Hyperbranched polyesters by polycondensation of fatty acid-based AB: N-type monomers
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Widely available vegetable oils were readily derivatized into chemically pure ABn-type monomers (n = 2 or 3). Their polymerization led to unprecedented hyperbranched polyesters. Four different AB2/AB3-type monomers bearing one A-type methyl ester and two or three B-type alcohol functions were purposely synthesized via two elementary steps, i.e. epoxidation of the internal double bond of the vegetable oil precursors followed by ring-opening of the epoxy groups under acidic conditions. The polycondensation of these bio-sourced monomers was performed in bulk, in the presence of an appropriate catalyst, giving access to modular hyperbranched polyesters with tunable properties. Among the catalysts tested, zinc acetate, 1,5,7-triazabicyclo[4.4.0]dec-5-ene (TBD) and sodium methoxide proved the most effective, allowing the achievement of molar masses in the range 3000-10000 g mol-1 and dispersities varying from 2 to 15, depending on the initial conditions. The degree of branching, DB, as determined by 1H NMR spectroscopy, was found to be between 0.07 and 0.45. The as-devised hyperbranched polyesters displayed either amorphous or semi-crystalline properties, as a function of the selected AB2/AB3-type initial monomers, with a glass transition temperature, Tg, ranging from -33 to 9 °C and a decomposition temperature at 5 wt% of the sample, Td5%, varying from 204 to 340 °C.
- Testud, Blandine,Pintori, Didier,Grau, Etienne,Taton, Daniel,Cramail, Henri
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- Mild catalytic oxidations of unsaturated fatty acid methyl esters (FAMEs) by oxovanadium complexes
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A selection of unsaturated fatty acid methyl esters, namely methyl oleate (C18:1), methyl linoleate (C18:2) and methyl linolenate (C18:3) has been oxidized under mild homogeneous catalytic conditions, using a series of oxovanadium(IV) complexes containing 4-acyl-5-pyrazolone donor ligands with different substituents on acyl residue. The main goal was to evaluate the catalytic role exerted by oxovanadium(IV) metal center, as precursor complex, in the selective oxyfunctionalization of carbon-carbon double bonds of these bio-renewable resources, as a greener alternative to more drastic processes currently used at the industrial level. The three substrates, oxidized using tert-butylhydroperoxide as main oxidant, with or without solvents, showed high conversions of starting materials and high selectivities in the formation of corresponding mono- di- and tri-epoxides, especially under solvent-less conditions. Investigations on a probable catalytic cycle mechanism operative in the tert-butylhydroperoxide oxidation of a simple FAME model substrate, have been performed by means of ESI-MS.
- Cecchini, Martina Maya,De Angelis, Francesco,Iacobucci, Claudio,Reale, Samantha,Crucianelli, Marcello
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- Fe(6-Me-PyTACN)-catalyzed, one-pot oxidative cleavage of methyl oleate and oleic acid into carboxylic acids with H2O2 and NaIO 4
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The first Fe-based catalytic system for the oxidative cleavage of unsaturated fatty acids and esters to carboxylic acids is reported. The system comprises [Fe(OTf)2(6-Me-PyTACN)] (2) (6-Me-PyTACN = 1-[(6-methyl-2-pyridyl)methyl]-4,7-dimethyl-1,4,7-triazacyclononane, OTf = trifluoromethane sulfonate anion) as the catalyst (3 mol%) either with a combination of hydrogen peroxide and NaIO4 or exclusively with NaIO4 as the oxidant, and operates at 0 °C or ambient temperature. Under these standard conditions (method A), methyl oleate is converted in a one-pot procedure into 50-55% of both nonanoic and azelaic acid, together with some epoxide and aldehyde intermediates as byproducts. These yields can be further improved by addition of sulfuric acid (method B) to hydrolyze the epoxide byproducts, by including a pH neutralization step and addition of more catalyst (1 mol%). Under the optimized conditions, both methyl oleate and oleic acid are converted into high yields of the corresponding carboxylic acids (80-85%). Overall, this catalytic system provides an alternative to the industrial ozonolysis of oleic acid and to catalytic Ru- and Os-based systems for the oxidative cleavage of unsaturated fatty acids and esters.
- Spannring, Peter,Prat, Irene,Costas, Miquel,Lutz, Martin,Bruijnincx, Pieter C. A.,Weckhuysen, Bert. M.,Klein Gebbink, Robertus J. M.
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- Amphiphilic dipyridinium-phosphotungstate as an efficient and recyclable catalyst for triphasic fatty ester epoxidation and oxidative cleavage with hydrogen peroxide
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A novel amphiphilic dipyridinium peroxophosphotungstate ion pair was developed as a selective and recyclable catalyst for the triphasic epoxidation of fatty acids and esters with hydrogen peroxide. The synthesis of the catalyst was studied extensively by solid and liquid phase 31P nuclear magnetic resonance (NMR). The oxidation of vegetable oils is of prime importance for the production of lubricants, plasticizers, polymer stabilizers and other olefinic compounds. Based on the oxidizing activity of peroxophosphotungstates, we designed a lipophilic phase transfer agent that renders the active complex insoluble in the reaction media, without having to support it on a matrix. This affords a catalyst combining the activity of homogeneous catalysts and the recyclability of heterogeneous systems. We show that this catalyst is able to fully epoxidize methyl oleate with excellent selectivity, with a turnover frequency of 149 at 60 °C, and can be easily recycled, to reach a record turn over number of 1868. A larger scale experiment on 13 grams and a scope including linoleic and ricinoleic acids were also demonstrated. The catalyst also shows excellent activity and selectivity for the oxidative cleavage of methyl oleate and the oxidation of small olefins.
- De La Garza, Luis Carlos,De Oliveira Vigier, Karine,Chatel, Gregory,Moores, Audrey
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- Valorization of Methyl Azelaaldehydate – A Vegetable Oil Based Platform Molecule for the Synthesis of Monomers through Stetter Reaction
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The valorization of vegetable oil-derived methyl azelaaldehydate (methyl 9-oxo-nonanoate) to monomers was studied through NHC-catalysed Stetter reaction. Among the Michael acceptors tested, dimethyl fumarate gave the highest selectivity (97 %) for the corresponding Stetter adduct, thus limiting the competing benzoin condensation.
- Charvieux, Aubin,Duc Vu, Nam,Duguet, Nicolas,Lemaire, Marc
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- Selective dihydroxylation of methyl oleate to methyl-9,10-dihydroxystearate in the presence of a recyclable tungsten based catalyst and hydrogen peroxide
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The dihydroxylation of fatty methyl esters is of prime importance for the synthesis of surfactants and lubricants. The conversion of methyl oleate (MO) to 98percent yield of methyl-9,10-dihydroxystearate (MDHS) was performed in the presence of H2O2 and H3PW12O40 catalyst in the absence of a phase transfer agent. The study of the effect of hydrogen peroxide concentration revealed that significant catalytic activity was only achieved for an optimal amount of H2O2. A mechanism for this reaction was proposed where hydrogen peroxide reacts with H3PW12O40 to produce peroxo-phosphotungstate anions, which directly dihydroxylate MO. The recyclability of the catalyst was also studied. To this aim, a recyclable form of the heteropolyacid was synthesized using Cs cations (Cs2.3H0.7PW12O40). This catalyst was recycled up to three cycles without significant loss in catalytic performances. This journal is
- Araji, Nahla,Chatel, Gregory,Moores, Audrey,Jér?me, Fran?ois,De Oliveira Vigier, Karine
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- Synthesis and biological properties of some novel heterocyclic homoprostanoids
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In the search for prostaglandin like structures capable of exerting specific and desirable biological properties, a variety of simple heterocyclic homoprostanoidal derivatives was synthesized from readily available stearic acid derivatives Compounds 5b and 5e were found to be more than 100 times as potent as PGE1 and PGE2 in a tracheal chain bioassay and, like 6, 9, and 12, inhibited PGE2 induced diarrhea. Derivatives 6 and 7a showed significant PG synthetase inhibitor activity.
- Bender,Berkoff,Groves,Sofranko,Wellman,Liu,Begosh,Horodniak
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- Triazolyl, Imidazolyl, and Carboxylic Acid Moieties in the Design of Molybdenum Trioxide Hybrids: Photophysical and Catalytic Behavior
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Three organic ligands bearing 1,2,4-triazolyl donor moieties, (S)-4-(1-phenylpropyl)-1,2,4-triazole (trethbz), 4-(1,2,4-triazol-4-yl)benzoic acid (trPhCO2H), and 3-(1H-imidazol-4-yl)-2-(1,2,4-triazol-4-yl)propionic acid (trhis), were prepared to evaluate their coordination behavior in the development of molybdenum(VI) oxide organic hybrids. Four compounds, [Mo2O6(trethbz)2]·H2O (1), [Mo4O12(trPhCO2H)2]·0.5H2O (2a), [Mo4O12(trPhCO2H)2]·H2O (2b), and [Mo8O25(trhis)2(trhisH)2]·2H2O (3), were synthesized and characterized. The monofunctional tr-ligand resulted in the formation of a zigzag chain [Mo2O6(trethbz)2] built up from cis-{MoO4N2} octahedra united through common μ2-O vertices. Employing the heterodonor ligand with tr/-CO2H functions afforded either layer or ribbon structures of corner- or edge-sharing {MoO5N} polyhedra (2a or 2b) stapled by tr-links in axial positions, whereas -CO2H groups remained uncoordinated. The presence of the im-heterocycle as an extra function in trhis facilitated formation of zwitterionic molecules with a protonated imidazolium group (imH+) and a negatively charged -CO2- group, whereas the tr-fragment was left neutral. Under the acidic hydrothermal conditions used, the organic ligand binds to molybdenum atoms either through [N-N]-tr or through both [N-N]-tr and μ2-CO2- units, which occur in protonated bidentate or zwitterionic tetradentate forms (trhisH+ and trhis, respectively). This leads to a new zigzag subtopological motif (3) of negatively charged polyoxomolybdate {Mo8O25}n2n- consisting of corner- and edge-sharing cis-{MoO4N2} and {MoO6} octahedra, while the tetradentate zwitterrionic trhis species connect these chains into a 2D net. Electronic spectra of the compounds showed optical gaps consistent with semiconducting behavior. The compounds were investigated as epoxidation catalysts via the model reactions of achiral and prochiral olefins (cis-cyclooctene and trans-β-methylstyrene) with tert-butylhydroperoxide. The best-performing catalyst (1) was explored for the epoxidation of other olefins, including biomass-derived methyl oleate, methyl linoleate, and prochiral dl-limonene.
- Lysenko, Andrey B.,Senchyk, Ganna A.,Domasevitch, Konstantin V.,Kobalz, Merten,Krautscheid, Harald,Cichos, Jakub,Karbowiak, Miroslaw,Neves, Patrícia,Valente, Anabela A.,Gon?alves, Isabel S.
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- Enzyme-mediated epoxidation of methyl oleate supported by imidazolium-based ionic liquids
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In the present manuscript we describe and discuss the use of hydrophobic and hydrophilic ionic liquids (ILs) as efficient supports to the enzyme-catalyzed epoxidation of biodiesel. The use of nine different lipases in three different ILs (BMI.PF6, BMI.NTf2 and BMI.BF 4) gave high biodiesel conversion rates in short reaction times using hydrogen peroxide (30%, v/v) as the epoxidation agent. A drastic behavior change is observed by altering the media from a hydrophobic IL to a hydrophilic IL. For instance, the use of Amano A. lipase (from Aspergillus niger) in hydrophilic BMI.BF4 yielded the epoxidized compound in 89% in the first reaction hour, and in the mean time, hydrophobic BMI.PF6 yielded the same product in 67%. The use of other lipases resulted in the desired epoxidized derivative and also in the 1,2-diol as a result of a reversible epoxy ring-opening promoted in the reaction media. Conversions and selectivities depended on the nature of the IL, on reaction time and on the selection of the lipase enzyme.
- Silva, Wendylene S.D.,Lapis, Alexande A.M.,Suarez, Paulo A.Z.,Neto, Brenno A.D.
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- Synthesis of Imidazoles from Fatty 1,2-Diketones
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Unsaturated vegetable oils and their corresponding fatty acid derivatives constitute interesting renewable platforms for the preparation of heterocycles, notably through the formation of oxygenated intermediates. In this work, fatty imidazoles were prepared from the corresponding 1,2-diketones through Debus-Radziszewski reaction. The reaction was optimized under microwave irradiation using a 1,2-diketone derived from methyl oleate and ammonium acetate as a nitrogen source. Using benzaldehyde as a model substrate, the reaction occurs at 180 °C for 5 min and the desired imidazole was formed in 96 % GC yield. A range of aldehydes was tested under the optimized conditions and the corresponding imidazoles were obtained in 33–99 % isolated yields (20 examples).
- Bouchakour, Mansouria,Daaou, Mortada,Duguet, Nicolas
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- Highly efficient nano-sized TS-1 with micro-/mesoporosity from desilication and recrystallization for the epoxidation of biodiesel with H2O2
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The epoxidation of the unsaturated fatty acid methyl esters (FAME) in biodiesel with H2O2 was investigated at 323 K in the liquid phase over microporous nano-sized TS-1 as well as micro-/mesoporous nano-sized TS-1. Nano-sized TS-1 with stacked morphology exhibits a catalytic activity per number of Ti sites up to 30% higher than a conventional, industrial TS-1 catalyst. Mesoporosity was successfully introduced by a desilication-recrystallization approach. Desilication by alkaline treatment in the presence of the structure-directing agent tetrapropylammonium cation (TPA+) or NaOH leads to the generation of undefined mesopores (10-40 nm), probably accompanied by an increase of the surface hydrophilicity. Consequently, the alkaline-treated materials show a two times lower catalytic activity in the epoxidation of biodiesel than the purely microporous parent material. The surfactant-assisted recrystallization of the alkaline-treated materials results in more uniform and smaller mesopores (3-10 nm). In the epoxidation, the recrystallized materials are remarkably more active with respect to both the purely microporous parent and alkaline-treated materials reaching a FAME conversion of 65% with an epoxide selectivity of 82%.
- Wilde,Pelz,Gebhardt,Gl?ser
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- Spongy titanosilicate promotes the catalytic performance and reusability of WO3 in oxidative cleavage of methyl oleate
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A tungsten containing catalyst catalyzed oxidative cleavage of methyl oleate (MO) by employing H2O2 as an oxidant and is known as an efficient approach for preparing high value-added chemicals, however, the tungsten leaching problem remains unresolved. In this work, a binary catalyst consisting of tungsten oxide (WO3) and spongy titanosilicate (STS) zeolite is proposed for MO oxidative cleavage. The function of STS in this catalyst is investigated. On the one hand, STS converts MO to 9,10-epoxystearate (MES), which further forms nonyl aldehyde (NA) and methyl azelaaldehydate (MAA) with the catalysis of WO3. In this way, MO oxidation and hydrolysis that generates unwanted diol product 9,10-dihydroxystearate (MDS) decreases obviously. On the other hand, STS decomposes peroxide and promotes the conversion of soluble peroxotungstate to insoluble polytungstate. Meanwhile, these tungsten species are allowed to precipitate on its surface instead of remaining in the liquid phase owing to its relative large specific area. Therefore, tungsten leaching can be reduced from 37.0% to 1.2%. Due to the cooperation of WO3 and STS, 94.4% MO conversion and oxidative cleavage product selectivity of 63.1% are achieved, and the WO3-STS binary catalyst maintains excellent catalytic performance for 8 recycling reactions.
- Huang, Zuoxin,Lin, Min,Peng, Xinxin,Shu, Xingtian,Xia, Changjiu,Xin, Shihao,Zhang, Yao,Zheng, Aiguo,Zhu, Bin
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p. 5135 - 5144
(2022/02/25)
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- Preparation method of 9, 10-dihydroxy stearate
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The invention discloses a preparation method of 9, 10-dihydroxy stearate, which comprises the following steps: uniformly mixing oleate and a catalyst, dropwisely adding a hydrogen peroxide solution, and reacting at 20-80 DEG C for 0.5-24 hours; and after the reaction is finished, removing a water layer, washing an oil layer with water, and drying to obtain the target product 9, 10-dihydroxy stearate. The catalyst is one or a mixture of two of phosphotungstic acid and supported phosphotungstic acid. According to the preparation method of the 9, 10-dihydroxy stearate, strong acids such as formicacid and sulfuric acid are not added, alkali is not required to be added for neutralization after the reaction is finished, and the 9, 10-dihydroxy stearate has the advantages of small corrosion to equipment, small environmental pollution, good selectivity, high activity and the like, meets the green and environment-friendly requirements and has an industrial application prospect.
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Paragraph 0031-0034; 0041-0046
(2021/03/31)
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- A Colorimetric Method for Quantifying Cis and Trans Alkenes Using an Indicator Displacement Assay
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A colorimetric indicator displacement assay (IDA) amenable to high-throughput experimentation was developed to determine the percentage of cis and trans alkenes. Using 96-well plates two steps are performed: a reaction plate for dihydroxylation of the alkenes followed by an IDA screening plate consisting of an indicator and a boronic acid. The dihydroxylation generates either erythro or threo vicinal diols from cis or trans alkenes, depending upon their syn- or anti-addition mechanisms. Threo diols preferentially associate with the boronic acid due to the creation of more stable boronate esters, thus displacing the indicator to a greater extent. The generality of the protocol was demonstrated using seven sets of cis and trans alkenes. Blind mixtures of cis and trans alkenes were made, resulting in an average error of ±2 % in the percentage of cis or trans alkenes, and implementing E2 and Wittig reactions gave errors of ±3 %. Furthermore, we developed variants of the IDA for which the color may be tuned to optimize the response for the human eye.
- Valenzuela, Stephanie A.,Crory, Hannah S. N.,Yao, Chao-Yi,Howard, James R.,Saucedo, Gabriel,de Silva, A. Prasanna,Anslyn, Eric V.
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supporting information
p. 13819 - 13823
(2021/05/17)
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- An assay for DNA polymerase β lyase inhibitors that engage the catalytic nucleophile for binding
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DNA polymerase β (Pol β) repairs cellular DNA damage. When such damage is inflicted upon the DNA in tumor cells treated with DNA targeted antitumor agents, Pol β thus diminishes their efficacy. Accordingly, this enzyme has long been a target for antitumor therapy. Although numerous inhibitors of the lyase activity of the enzyme have been reported, none has yet proven adequate for development as a therapeutic agent. In the present study, we developed a new strategy to identify lyase inhibitors that critically engage the lyase active site primary nucleophile Lys72 as part of the binding interface. This involves a parallel evaluation of the effect of the inhibitors on the wild-type DNA polymerase β (Pol β) and Pol β modified with a lysine analogue at position 72. A model panel of five structurally diverse lyase inhibitors identified in our previous studies (only one of which has been published) with unknown modes of binding were used for testing, and one compound, cis-9,10-epoxyoctadecanoic acid, was found to have the desired characteristics. This finding was further corroborated by in silico docking, demonstrating that the predominant mode of binding of the inhibitor involves an important electrostatic interaction between the oxygen atom of the epoxy group and Nε of the main catalytic nucleophile, Lys72. The strategy, which is designed to identify compounds that engage certain structural elements of the target enzyme, could find broader application for identification of ligands with predetermined sites of binding.
- Chen, Shengxi,Cheng, Qi,Daskalova, Sasha M.,Eisenhauer, Brian M.,Fahmi, NourEddine,Feng, Xizhi,Gao, Mingxuan,Hecht, Sidney M.,Ji, Xun,Khdour, Omar M.
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- LIPID CONJUGATE PREPARED FROM SCAFFOLD MOIETY
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The application relates to a lipid conjugate of formula M-X1-L wherein M is a molecule of interest such as a drug moiety; X1 is a linker group such as ester, ether or carbamate; and L is a lipid scaffold represented by formula (lId): -L1-[L2(H)(X2R)]n-L3-[L4(H)(X2R)]p-L5-L6 and wherein L comprises 5 to 40 carbon atoms and 0 to 2 carbon-carbon double bonds. The lipid conjugate can be formulated in a drug delivery vehicle such as a lipid nanoparticle (LNP).
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- Synthetic method of 9,10-dihydroxy C18 stearic acid methyl ester
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The invention discloses a synthetic method of 9,10-dihydroxy C18 stearic acid methyl ester, which is characterized by using epoxy fatty acid methyl ester as the raw material, and synthesizing the 9,10-dihydroxy C18 stearic acid methyl ester in one step under the action of a catalyst of sulfuric acid. The method particularly includes the following steps: the epoxy fatty acid methyl is added to a four-necked flask, then a cocatalyst of acetonitrile is added, and the catalyst of sulfuric acid is added to water and is added to the four-necked flask by dropping; after reaction, 9,10-dihydroxy C18 stearic acid methyl ester is obtained. After the reaction is completed, the aqueous phase is separated; then the reaction product is dissolved in an organic solvent, and a pure product is obtained after repeated recrystallization; and the organic solvent can be reused after distillation under reduced pressure. The 9,10-dihydroxy C18 stearic acid methyl ester synthesized by the method reaches a higher level in the yield and the purity, and the conversion rate of the reaction raw material is high, thereby achieving full utilization of the raw material.
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Paragraph 0023-0028
(2019/07/08)
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- Homogeneous and heterogeneous catalytic (dehydrogenative) oxidation of oleochemical 1,2-diols to α-hydroxyketones
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Herein, the preparation of methyl oleate α-hydroxyketone from the corresponding 1,2-diol was investigated using both homogeneous and heterogeneous systems. Homogeneous conditions using a Pd(OAc)2/neocuproine complex were first developed using oxygen as a sole oxidant under mild conditions (MeOH, 50 °C). Under these conditions, the conversion of diol reached 95%, and α-hydroxyketone was obtained with 97% selectivity. The access to α-hydroxyketone has also been studied by dehydrogenation using a range of heterogeneous catalysts under solvent-free conditions at high temperatures (160-180 °C). Dehydrogenation using activated Ru/C under vacuum provided α-hydroxyketone with 93% conversion and 82% GC yield. The optimized conditions were applied to a range of oleochemical diols, including a vegetable oil derivative, to obtain the corresponding α-hydroxyketones with up to 74% isolated yields.
- Vu, Nam Duc,Guicheret, Boris,Duguet, Nicolas,Métay, Estelle,Lemaire, Marc
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supporting information
p. 3390 - 3399
(2017/07/28)
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- Chemistry and Catalytic Performance of Pyridyl-Benzimidazole Oxidomolybdenum(VI) Compounds in (Bio)Olefin Epoxidation
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The chemistry and catalytic performance of the dichlorido complex [MoO2Cl2(pbim)] (1) [pbim = 2-(2-pyridyl)-benzimidazole] in the epoxidation of olefins is reported. Complex 1 acts as a precatalyst and is more effective with tert-butylhydroperoxide (TBHP) as the oxidant than with aq. hydrogen peroxide: the cis-cyclooctene (Cy) reaction with TBHP gave 98 % epoxide yield at 70 °C/24 h. Catalyst characterization showed that 1 is transformed in situ to the oxidodiperoxido complex [MoO(O2)2(pbim)] (2), with H2O2 and a hybrid molybdenum(VI) oxide solid formulated as [MoO3(pbim)] (3) with TBHP. The hybrid material 3 was prepared on a larger scale and explored for the epoxidation of the biorenewable olefins methyl oleate, methyl linoleate, and (R)-(+)-limonene. With TBHP as the oxidant, 3 acts as a source of soluble active species of the type 2. A practical method for recycling oxidodiperoxidomolybdenum(VI) catalysts for the Cy/TBHP reaction is demonstrated by using an ionic liquid as the solvent for the molecular catalyst 2.
- Neves, Patrícia,Nogueira, Lucie S.,Gomes, Ana C.,Oliveira, Tania S. M.,Lopes, André D.,Valente, Anabela A.,Gon?alves, Isabel S.,Pillinger, Martyn
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p. 2617 - 2627
(2017/05/29)
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- A phosphorus nitride oleic acid methyl ester green lubricating additive production method (by machine translation)
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The invention claims a phosphorus nitride oleic acid methyl ester green lubricating additive production method, comprising the following steps: adding oleic acid methyl ester with formic acid solution mixed in profile of the pan, then slowly dropping hydrogen peroxide, then warmed up to perform reaction, after the reaction is washed with distilled water and the upper oily liquid and vacuum dehydration, to obtain epoxidized oleic acid methyl ester; the epoxidized oleic acid methyl ester with distilled water, to join the phosphotungstic acid as catalyst, after the reaction separating upper hydroxylated oleic acid methyl ester; will be hydroxylated oleic acid methyl ester with phosphorus pentoxide mixed, constant temperature reaction 4h, then adding triethanolamine reaction 1h, after the reaction separating upper oily liquid and purification to obtain phosphorus nitride oleic acid methyl ester. The invention synthesis technique is simple, rich sources of raw materials, the production cost is low, and the obtained green lubricating additive has good biodegradability, can replace the traditional containing sulfur, phosphorus, chlorine lubricating additive. (by machine translation)
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- Dual functionality of amphiphilic 1-alkyl-3-methylimidazolium hydrogen sulfate ionic liquids: Surfactants with catalytic function
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A series of amphiphilic 1-alkyl-3-methylimidazolium hydrogen sulfate ionic liquids were synthesized. Acidic hydrogen sulfate ionic liquids with the alkyl chains C6-C14 are characterized by good surface properties. Their surface properties (adsorption and micellization parameters, degree of ionization of micelles, Krafft temperatures and thermodynamic parameters) were determined. Synthesized ionic liquids were applied as a co-catalyst in an oxirane ring opening reaction in epoxidized fatty acid methyl esters (FAME). Their co-catalytic activities were determined and discussed as a function of their structure and surface properties. It was found that the co-catalytic properties, both conversion and selectivity, of alkylimidazolium hydrogen sulfate ionic liquids noticeably depended on the alkyl chain lengths, and in consequence their properties.
- Nowicki, Janusz,?uczak, Justyna,Stańczyk, Dorota
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p. 11591 - 11601
(2016/02/09)
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- Structural and solubility parameter correlations of gelation abilities for dihydroxylated derivatives of long-Chain, naturally occurring fatty acids
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Creating structure-property correlations at different distance scales is one of the important challenges to the rational design of molecular gelators. Here, a series of dihydroxylated derivatives of long-chain fatty acids, derived from three naturally occurring molecules - oleic, erucic and ricinoleic acids - are investigated as gelators of a wide variety of liquids. Conclusions about what constitutes a more (or less!) efficient gelator are based upon analyses of a variety of thermal, structural, molecular modeling, and rheological results. Correlations between the manner of molecular packing in the neat solid or gel states of the gelators and Hansen solubility data from the liquids leads to the conclusion that diol stereochemistry, the number of carbon atoms separating the two hydroxyl groups, and the length of the alkanoic chains are the most important structural parameters controlling efficiency of gel formation for these gelators. Some of the diol gelators are as efficient or even more efficient than the well-known, excellent gelator, (R)-12-hydroxystearic acid; others are much worse. The ability to form extensive intermolecular H-bonding networks along the alkyl chains appears to play a key role in promoting fiber growth and, thus, gelation. In toto, the results demonstrate how the efficiency of gelation can be modulated by very small structural changes and also suggest how other structural modifications may be exploited to create efficient gelators.
- Zhang, Mohan,Selvakumar, Sermadurai,Zhang, Xinran,Sibi, Mukund P.,Weiss, Richard G.
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supporting information
p. 8530 - 8543
(2015/06/02)
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- LUBRICITY IMPROVER
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Provided is a lubricity improver capable of improving lubricity and storage stability due to anti-oxidation, the lubricity improver containing a saturated fatty acid methyl ester derivative including at least one 1,2-dimethoxy ethylene structural unit represented by Chemical Formula a below, obtained by converting a double bond (olefin) of biodiesel, which is used as a lubricity improver of fuel, that is, the existing fatty acid methyl ester (FAME), into a dimethoxy group.
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Paragraph 0037; 0040
(2013/03/26)
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- Efficient ruthenium-catalysed oxidative cleavage of methyl oleate with hydrogen peroxide as oxidant
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The oxidative cleavage of alkenes leads to the formation of carboxylic acids. One of the few technical processes using this reaction is the production of azelaic acid via the ozonolysis of oleic acid. Because of the need for stoichiometric amounts of the expensive oxidant ozone, together with safety hazards, there is still a requirement for a catalytic process using a cheap and environmentally friendly oxidant. In the present work, the oxidative cleavage of methyl oleate by hydrogen peroxide was catalysed by an easily available ruthenium precursor with dipicolinic acid as ligand. The systematic optimisation of the reaction led to the formation of azelaic acid monomethyl ester in high yields amounting to 86%. The investigation of the reaction pathway showed that the reaction proceeds via a tandem reaction of epoxidation and hydrolysis of the epoxide and oxidative cleavage of the vic-diol. The Royal Society of Chemistry.
- Behr, Arno,Tenhumberg, Nils,Wintzer, Andreas
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p. 172 - 180
(2013/04/23)
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- Fe-catalyzed one-pot oxidative cleavage of unsaturated fatty acids into aldehydes with hydrogen peroxide and sodium periodate
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A one-pot method has been developed for the oxidative cleavage of internal alkenes into aldehydes by using 0.5mol % of the nonheme iron complex [Fe(OTf)2(mix-bpbp)] (bpbp=N,N'-bis(2-picolyl)-2,2'-bipyrrolidine) as catalyst and 1.5equivalents of hydrogen peroxide and 1equivalent of sodium periodate as oxidants. A mixture of diastereomers of the chiral bpbp ligand can be used, thereby omitting the need for resolution of its optically active components. The cleavage reaction can be performed in one pot within 20h and under ambient conditions. Addition of water after the epoxidation, acidification and subsequent pH neutralization are crucial to perform the epoxidation, hydrolysis, and subsequent diol cleavage in one pot. High aldehyde yields can be obtained for the cleavage of internal aliphatic double bonds with cis and trans configuration (86-98 %) and unsaturated fatty acids and esters (69-96 %). Good aldehyde yields are obtained in reactions of trisubstituted and terminal alkenes (62-63 %). The products can be easily isolated by a simple extraction step with an organic solvent. The presented protocol involves a lower catalyst loading than conventional methods based on Ru or Os. Also, hydrogen peroxide can be used as the oxidant in this case, which is often disproportionated by second- and third-row metals. By using only mild oxidants, overoxidation of the aldehyde to the carboxylic acid is prevented. Copyright
- Spannring, Peter,Yazerski, Vital,Bruijnincx, Pieter C. A.,Weckhuysen, Bert M.,Klein Gebbink, Robertus J. M.
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p. 15012 - 15018
(2013/11/06)
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- Cork suberin molecular structure: Stereochemistry of the C18 epoxy and vic-diol ω-hydroxyacids and α,ω-diacids analyzed by nmr
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Suberin is the biopolyester that protects the secondary tissues of plants against environmental variability and aggressions. Cork suberin is composed mostly of C18 ω-hydroxyacids and α,ω-diacids, 9,10-substituted with an unsaturation, an epoxide ring, or a vic-diol group. Although determinant for suberin macromolecular structure, the stereochemistry of these monomers is poorly studied, sometimes with contradictory results. An NMR technique was used here to assign the configuration of the 9,10-epoxy and 9,10-diol groups in C18 suberin acids, comparing the chemical shifts of diagnostic 1H and 13C signals with the ones of model compounds, before and after conversion of the vic-diol group into benzylidene acetal derivatives. The relative configuration was proved to be cis in the C18 9,10-epoxy and threo in the C18 9,10-diol suberin acids. These monomers were present in suberin probably as racemic mixtures, as shown by polarimetry. The revealed stereochemistry allows the suberin macromolecule to be built as an ordered array of midchain kinked C18 acids, reinforced by intramolecular hydrogen bonding.
- Santos, Sara,Cabral, Vanessa,Graca, Jose
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p. 7038 - 7047
(2013/08/23)
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- METHOD FOR PREPARING CARBOXYLIC ACIDS BY OXIDATIVE CLEAVAGE OF A VICINAL DIOL
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The present invention relates to a method for preparing carboxylic acids, in particular mono- and dicarboxylic acids, by oxidative cleavage of a vicinal diol. According to the invention, said method consists of reacting a vicinal diol of formula I: where: p is an integer comprised between 1 and 6; R1 and R2 are, separately: an alkyl or hydroxyl group having 1 to 12 carbon atoms;a —(CH2)n—C02M group where n, which can be identical or different in R1 and R2, is an integer comprised between 1 and 11 and M is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms or an alkaline cation; or R1 and R2 jointly form an alkylene —(CH2)m- group where m is an integer comprised between 2 and 10, preferably between 2 and 6; with industrial-grade sodium hypochlorite (or bleach), in the absence of an organic solvent and without adding a catalyst, preferably at room temperature. The invention can be used for recycling natural vegetable oils.
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Paragraph 0067; 0068; 0069; 0070; 0071
(2013/06/04)
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- An efficient ring opening reaction of methyl epoxystearate promoted by synthetic acid saponite clays
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The acid-catalysed reaction of methyl 9,10-epoxystearate ring opening using synthetic saponite acid clay as catalyst, has been studied for the first time. In the presence of methanol, 90% of the epoxide substrate is converted after 5 min and the main reaction product is the vicinal hydroxyether, methyl methoxyhydroxystearate, with 84% of selectivity. In the absence of alcohol the ring opening reaction proceeds slower, leading to a mixture of methyl 9- and 10-oxostearate as main products, and a 9,10-epoxystearate conversion of 66% after 1 h. The performance of acid saponite, an environmentally benign catalyst, is exceedingly higher than those of strong mineral acids, such as H 2SO4, widely used for this reaction.
- Guidotti, Matteo,Psaro, Rinaldo,Ravasio, Nicoletta,Sgobba, Maila,Carniato, Fabio,Bisio, Chiara,Gatti, Giorgio,Marchese, Leonardo
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supporting information; experimental part
p. 1173 - 1178
(2010/05/18)
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- IMPROVED PROCESS FOR THE PRODUCTION OF DERIVATIVES OF SATURATED CARBOXYLIC ACIDS
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A process for the production of carboxylic acids and their derivatives comprising the steps of: (c) reacting a derivative of an unsaturated fatty acid with an oxidizing compound in the presence of a catalyst capable of catalysing the reaction of oxidation of the double olefinic bond of the derivative of the unsaturated fatty acid so as to obtain as intermediate product of reaction a vicinal diol; and (d) reacting said intermediate compound with oxygen, or a compound containing oxygen, in the presence of a catalyst capable of catalysing the reaction of oxidation of the hydroxyl groups of the vicinal diol to carboxylic groups, characterized in that both of the steps (a) and (b) are carried out in the absence of added organic solvent and in that the water/diol ratio in the reaction of step (b) is less than 1:1.
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Page/Page column 5-6; 6-7
(2008/06/13)
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- Hydrolysis of Mono- and Diepoxyoctadecanoates by Alumina
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In this study it is shown that the epoxide derivative of oleic acid, methyl 9, 10-epoxyoctadecanoate, is readily hydrolyzed to a diol when exposed to a commercial preparation of neutral alumina. Comparison of 1H and 13C NMR spectra of the diol with those of standards showed that the product was the threo isomer. When methyl 9, 10-12, 13-diepoxyoctadecanoate was treated with alumina, a mixture of dihydroxytetrahydrofuran regioisomers, methyl 9, 12-epoxy-10, 13-dihydroxystearate and methyl 10, 13-epoxy-9, 12-dihydroxystearale, was obtained. These results show that alumina is an unsuitable support for epoxidation catalysts. However, alumina-catalyzed hydrolysis of fatty epoxides is an efficient way to synthesize polyhydroxy materials, and these materials are suitable for several industrial applications.
- Piazza, George J.,Nunz, Alberto,Foglia, Thomas A.
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p. 901 - 904
(2007/10/03)
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- Synthesis of enantioenriched methyl vic-dihydroxystearates
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Several enantioenriched methyl vic-dihydroxystearates 4 have been synthesized from methyl octadecenoates by enantioselective dihydroxylation in good yields (85-97%) and with satisfactory enantiomeric excess (ee 80-97%). The enantioenriched anti-9,10 dihydroxystearates (anti-4c) were prepared by HPLC separation of the corresponding dicamphanyl esters anti-6. Their ee was determined by HPLC of the corresponding diastereoisomeric carbamates 7, and their configuration was assigned by relation to a described compound or by applying the mnemonic device of Sharpless.
- Plate, Mark,Overs, Michael,Sch?fer, Hans J.
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p. 1255 - 1258
(2007/10/03)
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- A facile, versatile procedure for the preparation of fatty acid esters suitable for glc or hplc analyses
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The preparation of fatty acid methyl esters for glc analyses and of various aryl esters for hplc analyses has traditionally been carried out in totally unrelated operations.This paper draws attention to the use of fatty acid-trifluoroacetic acid mixed anhydrides which may be directly and efficiently converted into either type of esters.The utility of the method was demonstrated by the preparation of series of methyl, 2-naphthyl, and vanillin fatty acid esters.The spectral characterization of some aryl fatty acid esters is recorded.
- Grossert, J. Stuart,Ratnayake, W. M. Nimal,Swee, Tiw
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p. 2617 - 2620
(2007/10/02)
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- Heterocyclic homoprostanoidal derivatives
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Heterocyclic homoprostanoidal derivatives are prepared. These compounds have valuable antiprostaglandin activity specifically inhibiting prostaglandin synthesis and antagonizing diarrhea induced by prostaglandin E2 (PGE2).
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