Ether Compounds Research Articles

Chemical composition and neurotherapeutic potential of Glaucium corniculatum extracts

Background: The discovery of natural agents that suppress neural apoptosis is of strategic importance for the treatment of neurodegenerative diseases. Glaucium corniculatum has been used as a traditional medicine because of its memory-enhancing and neuroprotective properties. However, there has not been a study about this plant's apoptosis suppressive properties until now. Objectives: The present study examines the possible suppressive effects on apoptosis of three different G. corniculatum extracts (chloroform, methanol, and water) in neuronal-differentiated PC12 (dPC12) cells induced by hydrogen peroxide (H2O2) and presents the first association of compound content differences in extracts with the suppressive property. Materials and Methods: The chemical composition of these extracts was analyzed by Fourier transform infrared spectroscopy (FTIR) and gas chromatography-mass spectroscopy. The changes caused by the extracts in apoptotic markers were examined by real-time quantitative polymerase chain reaction and Western blot. Results: Extracts contained alkaloid, fatty acid, alcohol, alkane hydrocarbon, ester, ether, alkane, alkene, aliphatic, aromatic, and phenolic compounds with different relative proportions. In all the three extracts, the major compound was allocriptopine. Oleamide and 2-monopalmitin were the major fatty acids, respectively, identified in water and methanol extracts. Extracts were suppressed H2O2-induced apoptosis via decreasing the expression of Bax, Caspase-3 and -9, while increasing Bcl-2, in a concentration-dependent manner. The water extract showed the highest apoptosis suppression while methanol was the second. Conclusion: G. corniculatum extracts suppress apoptosis in dPC12 cells and allocriptopine, oleamide, and 2-monopalmitin may be responsible of apoptosis suppressive effect.

Chemistry of Tertiary Carbon Center in the Formation of Congested C−O Ether Bonds

Nucleophilic substitutions, including SN 1 and SN 2, are classical and reliable reactions, but a serious drawback is their intolerance for both bulky nucleophiles and chiral tertiary alkyl electrophiles for the synthesis of a chiral quaternary carbon center. An SRN 1 reaction via a radical species is another conventional method used to carry out substitution reactions of bulky nucleophiles and alkyl halides, but chiral tertiary alkyl electrophiles cannot be used. Therefore, a stereospecific nucleophilic substitution reaction using chiral tertiary alkyl electrophiles and bulky nucleophiles has not yet been well studied. In this paper, we describe the reaction of tertiary alkyl alcohols and non-chiral or chiral α-bromocarboxamides as a tertiary alkyl source for the formation of congested ether compounds possessing two different tertiary alkyl groups on the oxygen atom with stereoretention.

Chemistry of Tertiary Carbon Center in the Formation of Congested C−O Ether Bonds

AbstractNucleophilic substitutions, including SN1 and SN2, are classical and reliable reactions, but a serious drawback is their intolerance for both bulky nucleophiles and chiral tertiary alkyl electrophiles for the synthesis of a chiral quaternary carbon center. An SRN1 reaction via a radical species is another conventional method used to carry out substitution reactions of bulky nucleophiles and alkyl halides, but chiral tertiary alkyl electrophiles cannot be used. Therefore, a stereospecific nucleophilic substitution reaction using chiral tertiary alkyl electrophiles and bulky nucleophiles has not yet been well studied. In this paper, we describe the reaction of tertiary alkyl alcohols and non‐chiral or chiral α‐bromocarboxamides as a tertiary alkyl source for the formation of congested ether compounds possessing two different tertiary alkyl groups on the oxygen atom with stereoretention.

Photoinduced Transformation of Uranyl Nitrate Crown Ether Compounds

AbstractThe uranyl cation, (U(VI)O2)2+, has previously demonstrated photocatalytic reactivity in organic solutions, which results in the formation of uranyl peroxide species. Past studies indicated that the phototransformation process typically ends with the formation of uranyl peroxide solid phases. In the current study, we explore the transformation of uranyl nitrate crown ether complexes, (18‐crown‐6)[UO2(NO3)2(H2O)2] ⋅ 2 H2O (1 a), (18‐crown‐6)[UO2(NO3)2(H2O)2] (1 b), and (18‐crown‐6) [K(18‐crown‐6)] [(UO2)2(OH)2(NO3)4(H2O)4] (2) in the presence of ethanol to create a uranyl peroxide intermediate phase, (18‐crown‐6)[(UO2)2(O2)(NO3)2(H2O)4] (3), followed by a second alteration to a black solid (4). These compounds were structurally evaluated using both single‐crystal and powder X‐ray diffraction and then further characterized using Raman, NMR, and XPS spectroscopy. The initial transformation from the yellow uranyl nitrate phase (1 a, 1 b, and 2) to the uranyl peroxide (3) follow previously reported mechanisms. The second transformation to the black phase (4) is likely due to additional degradation of the 18‐crown‐6 molecule as a result of hydrogen abstraction and ring‐opening. In addition, we discuss the nature of confinement effects to impact the hydrogen abstraction process and the possibility that nitrate anions in the system may synergistically enhance the degradation process and lead to the formation of 4.

Catalytic hydrogenation and etherification of 5-Hydroxymethylfurfural into 2-(alkoxymethyl)-5-methylfuran and 2,5-bis(alkoxymethyl)furan as potential biofuel additives

In this study, 5-hydroxymethylfurfural (HMF) was converted into several biofuel additives such as alkoxymethylfurans (AMFs) and 2,5-bis(alkoxymethyl)furans (BAMFs) through two-step sequential hydrogenation and etherification reactions. In the first step, zinc‑iron magnetic nanocatalyst supported on activated carbon (ZnO-Fe3O4/AC) was prepared for the selective hydrogenation of HMF into BHMF and 5-MFA via Meerwein-Ponndorf-Verley (MPV) reaction in three different hydrogen donor alcohols (ethanol, 1-propanol, and 1-butanol). The important physical properties of the catalyst such as crystallinity, chemical composition, morphology, reduction behavior, and surface area were studied by using several analytical techniques. The effect of hydrogenation parameters such as catalyst concentration, temperature, and time on the selectivity of (BHMF and 5-MFA), and HMF conversion were studied. The best hydrogenation results were obtained with 0.2 mmole HMF and 100 mg of catalyst at 200 °C for 12 h. In the second step, three commercial Brønsted acid catalysts were used to convert the hydrogenated products into alkoxymethylfurans (AMFs) and 2,5-bis(alkoxymethyl)furans (BAMFs). At the optimum etherification conditions (65 °C and 10 h), a spectrum of mono-, di-, and tri- ether compounds were obtained. The hydrogenation catalyst (ZnO-Fe3O4/AC) was recycled and used for five times without a remarkable reduction in its catalytic activity.

Revisiting the mechanism of \u03b2-O-4 bond cleavage during acidolysis of lignin VII: acidolyses of non-phenolic C6-C2-type model compounds using HBr, HCl and H2SO4, and a proposal on the characteristic action of Br\u2212 and Cl\u2212

A non-phenolic C6-C2-type lignin model compound with the β-O-4 bond, 2-(2-methoxyphenoxy)-1-(3,4-dimethoxyphenyl)ethanol (I), was acidolyzed in aqueous 82% 1,4-dioxane containing HBr, HCl, or H2SO4 with a concentration of 0.2 mol/L at 85 ℃ to examine the differences between these acidolyses. Compound I primarily converted to an enol ether compound, 1-(2-methoxyphenoxy)-2-(3,4-dimethoxyphenyl)ethene (II), via the benzyl cation followed by acidolytic β-O-4 bond cleavage regardless of the acid-type, although the disappearance rates of compound I were remarkably different (HBr > HCl >> H2SO4). Acidolyses of compound II using these acids under the same conditions showed a similar tendency, but the rate differences were much smaller than in the acidolyses of compound I. Acidolyses of the α-methyl-etherified derivative of compound I (I-α-OMe) using these acids under the same conditions suggested that the formation rates of the benzyl cation from compound I-α-OMe (also from compound I) are not largely different between the acidolyses using these acids, but those of compound II from the benzyl cation are remarkably different. Acidolysis of the α-bromo-substituting derivative of compound I (I-α-Br) using HBr under the same conditions showed a characteristic action of Br¯ in the acidolysis. Br¯ adds to the benzyl cation generated from compound I or I-α-OMe to afford unstable compound I-α-Br, resulting in acceleration of the formation of compound II and of the whole acidolysis reaction.

Extraction of Au(III) using aromatic ethers via ion solvation from acidic chloride media: Structural factors that influence extraction

Ethereal compounds, such as the commercially available extractant dibutyl carbitol (DBC), can extract Au(III) from acidic chloride media by ion solvation. Herein, various aromatic ether compounds comprising an aromatic ring and aliphatic chains were prepared to compare the extraction affinity toward Au(III) without dilution. Aromatic monoethers are not useful for the extraction of Au(III). Conversely, the extraction of Au(III) using aromatic 1,2-diethers increases as a function of hydrochloric acid concentration. For aromatic 1,2-diethers, the shorter the aliphatic chain, the higher the extraction affinity toward Au(III). 1,2-Dimethoxybenzene (o-DMB), which has the shortest side chains, exhibits the highest extraction affinity. 1,3-Dimethoxybenzene (m-DMB), which is a regioisomer for o-DMB, was not suitable for the extraction of Au(III). The extraction selectivity toward Au(III) over that of Fe(III) and Ga(III) using o-DMB, under high concentrations of hydrochloric acid, is higher than that using DBC. Selected aromatic 1,2-diethers, including o-DMB, show a significantly higher extraction capacity toward Au(III) than the industrial requirement of 30 g/dm3. Au(III) extracted using o-DMB was quantitatively recovered by reduction with oxalic acid. In a separation test from a mixed system comprising seven metals, Au(III) was selectively extracted and with a recovery percentage, after reduction, reaching 95.7%.

Synthesis of Network Polymers by Means of Addition Reactions of Multifunctional-Amine and Poly(ethylene glycol) Diglycidyl Ether or Diacrylate Compounds.

Addition reactions of multi-functional amine, polyethylene imine (PEI) or diethylenetriamine (DETA), and poly(ethylene glycol) diglycidyl ether (PEGDE) or poly(ethylene glycol) diacrylate (PEGDA), have been investigated to obtain network polymers in H2O, dimethyl sulfoxide (DMSO), and ethanol (EtOH). Ring opening addition reaction of the multi-functional amine and PEGDE in H2O at room temperature or in DMSO at 90 °C using triphenylphosphine as a catalyst yielded gels. Aza-Michael addition reaction of the multi-functional amine and PEGDA in DMSO or EtOH at room temperature also yielded corresponding gels. Compression test of the gels obtained with PEI showed higher Young’s modulus than those with DETA. The reactions of the multi-functional amine and low molecular weight PEGDA in EtOH under the specific conditions yielded porous polymers induced by phase separation during the network formation. The morphology of the porous polymers could be controlled by the reaction conditions, especially monomer concentration and feed ratio of the multi-functional amine to PEGDA of the reaction system. The porous structure was formed by connected spheres or a co-continuous monolithic structure. The porous polymers were unbreakable by compression, and their Young’s modulus increased with the increase in the monomer concentration of the reaction systems. The porous polymers absorbed various solvents derived from high affinity between the polyethylene glycol units in the network structure and the solvents.

Antiproliferative response induced Euphorbia umbellata fractions and subfractions in melanoma and hepatocellular carcinoma tumor cells

Resistance to the therapies currently offered for melanoma and hepatocellular carcinoma requires new research that seeks more effective therapeutic agents with less toxicity. The present study aimed to evaluate the antiproliferative, antitumor effects and the modulation of the mitochondrial electrical potential of the Acetate and Chloroform fractions and the sub-fractions Methanol, Ethanol, Dichloromethane and Ether, isolated from E. umbellata latex sap in murine melanoma cells (B16 -F10), hepatocellular carcinoma tumor cells (Hepa1c1c7) and normal fibroblast cells (FN1). The Acetate and Chloroform fractions showed significantly cytotoxic potential for tumor cells B16-F10 and Hepa1c1c7, in addition to the fractions being sensitive to the ether and methanol compounds. Such compounds promoted the reduction of cell confluence, the modulation of mitochondrial electrical potential, the depolarization of the mitochondrial membrane, and the release of pro-apoptotic mechanisms that resulted in the death of both tumor lines.

Bioassay-guided isolation and antiproliferative efficacy of extract loaded in chitosan nanoparticles and LC-QTOF-MS/MS analysis of Achillea magnifica

This study investigated the antioxidant, anti-urease, anticholinesterase, and antiproliferative activities of different extracts of A. magnifica. The active compounds were isolated from chloroform extract, which has the strongest antiproliferative and antioxidant activities. The structures of the isolated compounds (elenolic acid, luteolin, eupatilin) were examined using spectroscopic techniques (NMR, UV, HR-MS). The antioxidant and antiproliferative effects of isolated compounds showed lower biological activity than those of the chloroform extract. Therefore, chitosan nanoparticles were prepared with this extract and characterized. The cytotoxic activities of the chitosan nanoparticles were examined, and they were found to have a strong antiproliferative activity similar to that of the chloroform extract. The ethanol extract had strong anti-urease and anticholinesterase activity compared with other extracts. Therefore, phenolic compounds that might be responsible for the biological activity were analysed by LC-QTOF-MS/MS. The ferulic acid derivative, apigenin-6-C-pentoside-8-C-hexoside, apigenin 6,8-di C-hexoside, vitexin, and diosmetin 8-C-glucoside (orientin 4′-methyl ether) compounds from this plant were analysed for the first time. The results showed that the chloroform-loaded chitosan nanoparticles had a strong antiproliferative activity in breast cancer cell lines (MCF-7, MDA-MB-231) and no toxic effect on normal cell lines (L-929), which suggested that this extract might be a potential candidate as a herbal medicine that can be investigated and evaluated in future cancer studies. Additionally, the potential use of ethanol extract as an anti-urease and anticholinesterase agent was revealed.

Achieving ultrahigh glass transition temperature, halogen-free and phosphorus-free intrinsic flame retardancy for bismaleimide resin through building network with diallyloxydiphenyldisulfide

A novel type of intrinsic flame retardant thermosetting resin without halogen and phosphorus elements (BDS) was developed based on building crosslinked network with a new disulfide-containing aryl allyl ether compound (DS) and bismaleimide. The molar ratio of DS to bismaleimide has a significant effect on performances of BDS resins, the resin (BDS-0.86) of which the molar ratio of DS to bismaleimide is 0.86 shows the best integrated performances including outstanding flame retardancy, high flexural strength (128.2 ± 8.6 MPa) and the highest glass transition temperature (336 °C) among halogen-free and phosphorus-free flame retarding bismaleimide resins reported so far. The origin of superior integrated performances of BDS-0.86 was intensively discussed from molecular structures and curing mechanism.

Synthesis of polymer networks by means of addition reactions of tri-amine and poly(ethylene glycol) diacrylate or diglycidyl ether compounds

Polymer networks have been synthesized by addition reactions of tri-functional amine, tris(2-aminoethyl)amine (TAEA) or trimethylolpropane tris[poly(propylene glycol)amine terminated] ether (PPGTA), and poly(ethylene glycol) diacrylate (PEGDA), or poly(ethylene glycol) diglycidyl ether (PEGDE) in dimethyl sulfoxide (DMSO) as a solvent. These reactions yielded the gels in which the polymer networks were homogeneously swollen in DMSO. An increase in the monomer concentration increased Young’s modulus and breaking stress of the gels. The gels with PPGTA showed flexible features in comparison with those with TAEA due to the flexible molecular structure of PPGTA. The gels composed of TAEA and PEGDA or PEGDE with high molecular weight tended to show lower Young’s modulus and higher breaking strain than the gels composed of those with low molecular weight due to the decrease in the cross-linking density and/or increase in flexibility of the PEG unit accompanied by the increase in the molecular weight of PEG. The gels with PPGTA showed opposite tendency, indicating entanglement of PEG unit with high molecular weight, which would play a role of physical cross-linking points in the gels. The gels prepared in N,N-dimethylformamide (DMF) were flexible in comparison with the gels prepared in DMSO due to the high miscibility of the network and DMF. The reaction systems of TAEA and PEGDA with low molecular weight in ethanol formed porous polymeric networks derived from the phase separation during the polymerization. The porous polymeric networks were unbreakable by compression and absorbed various organic solvents.

Data-Driven Advancement of Homogeneous Nickel Catalyst Activity for Aryl Ether Cleavage

The increasing urgency to make chemical processes more environmentally friendly while continuing to derive the chemicals required for modern society from renewable resources requires the development of a forthcoming generation of synthetic processes and the catalysts needed to facilitate these reactions. Recently, applications of machine-learning (ML) algorithms involving catalysis have begun to appear with increasing frequency, as they constitute an attractive pathway both for discovering prospective species and identifying trends surrounding catalytic behavior, principally because the number of potential catalysts that can be examined greatly exceeds those found in more traditional experimental or theoretical approaches. Here, we harness a data-driven approach powered by ML in tandem with molecular volcano plots to estimate the activity of over 143,000 homogeneous nickel catalysts bearing phosphine and N-heterocyclic carbene ligands for the reductive C(sp2)–O cleavage reaction in aryl ether compounds, an important step in the degradation of biomass (lignin) into industrially useful feedstock chemicals. Our computational workflow reveals that a vast majority of Ni-phosphine and Ni-carbene catalysts are not ideally tuned to facilitate this reaction. An analysis of those species identified as being the most promising uncovers a clear catalytic design strategy that can be exploited in an experimental setting to enhance the rate of reductive C(sp2)–O cleavage of aryl ether compounds.

Direct Solvent Liquefaction of Tropical Hardwood Bark and Characterization of the Resulting Bio-Oil

Ethanol, water and ethanol/water mix were used to directly liquefy Detarium senegalense bark at 500°C for 15 min. Ethanol/water mix at 50/50% weight by weight showed synergistic effect on biomass direct liquefaction, and was found to be the most effective solvent for the liquefaction of Detarium senegalense bark. Water was more active than Ethanol when both mono-solvents were evaluated. Liquefaction with 100% water yielded 46% by weight of the bio-oil, compared with 30% by weight of bio-oil yield when 100% ethanol was used. The result however, show that 50% ethanol/water showed a synergistic effect and work best to obtain 52% bio-oil on the liquefaction whereas water was found hence more active than ethanol as a single solvent with 46% and 30% bio-oil respectively.
 The GC-MS analysis of the obtained bio-oils from the three matrices confirmed the presence of phenolic compounds and aromatics such as benzenes, followed by aldehydes, long chain ketones and cyclic ketones and alcohol, esters, organic acids and ether compounds. The detected phenolic compounds were 4-ethyl-guaiacol, 2-methoxy-4-(2-propenyl)-phenol, 2-methoxy-phenol, and 2-methoxy-4-vinyl-phenol., formed from the cleavage of guaiacyl and hydroxyphenyl-type lignin with varying degrees of alcohol substitution. Understanding and evaluating the liquefied products obtained from hardwood barks, could offer valuable information on the utilization of the biomass-liquefaction products for chemical or energy production.

Dielectric relaxation study of aqueous ethylene glycol mono-methyl ether (EGME) with water using time domain reflectometry technique in the frequency range 10MHz to 50GHz

The Complex permittivity spectra of glycol ether (GE) compounds such as ethylene glycol mono-methyl ether (EGME) with water mixture over entire concentration range and in temperature range of 10–25∘C have been determined using Time Domain Reflectometry (TDR) technique in the frequency range 10[Formula: see text]MHz to 50[Formula: see text]GHz. The complex permittivity spectra for EGME-water were fitted in the Cole–Davidson model. The Static dielectric constant ([Formula: see text], Relaxation time ([Formula: see text], effective Kirkwood correlation factor ([Formula: see text], excess permittivity ([Formula: see text], thermodynamic parameters (activation enthalpy and activation entropy) and Bruggeman factor ([Formula: see text] have been calculated by the nonlinear least square fit method. The intermolecular interactions between EGME-water binary mixtures suggest the nonlinear behavior of dielectric parameters. The contribution of hydrogen bonding interactions among the solute–solvent mixtures is confirmed by Excess properties and Bruggeman factor.

MP07-06 CHRONIC LL-37 INDUCED CYSTITIS PRODUCES PAIN INDEPENDENT OF INFLAMMATION AND MODIFIED GLYCOSAMINOGLYCANS ARE POTENT NON-OPIOID ANALGESICS

You have accessJournal of UrologyInfections/Inflammation/Cystic Disease of the Genitourinary Tract: Interstitial Cystitis (MP07)1 Apr 2020MP07-06 CHRONIC LL-37 INDUCED CYSTITIS PRODUCES PAIN INDEPENDENT OF INFLAMMATION AND MODIFIED GLYCOSAMINOGLYCANS ARE POTENT NON-OPIOID ANALGESICS Austin Schults*, Wanjian Jia, M. Martin Jensen, Glenn Prestwich, and Siam Oottamasathien Austin Schults*Austin Schults* More articles by this author , Wanjian JiaWanjian Jia More articles by this author , M. Martin JensenM. Martin Jensen More articles by this author , Glenn PrestwichGlenn Prestwich More articles by this author , and Siam OottamasathienSiam Oottamasathien More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000000827.06AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: Interstitial cystitis/painful bladder syndrome (IC/PBS) can be a debilitating condition that dramatically impacts the quality of life for patients. The primary goal of patients with IC/PBS is to provide symptomatic relief. The immunomodulatory human cathelicidin (antimicrobial peptide) LL-37 induces profound acute bladder inflammation and pain. Our objectives were to evaluate a chronic pain profile associated with an LL-37-induced murine model of IC/PBS, along with the analgesic effects of modified glycosaminoglycan ether compounds. We hypothesized that chronic pain could be produced that is independent of inflammation and that a semi-synthetic glycosaminoglycan ether (SAGE GM-0111) could be a potent non-opioid analgesic in the setting of chronic LL-37-induced cystitis. METHODS: Bladder instillation of 150μL of 80 µM LL-37 for 1-hr, biweekly for four weeks induced the chronic IC/PBS model. SAGE analgesic effects were tested by instilling SAGE GM-0111. Pain responses to suprapubic stimulation were assessed using von Frey filaments (0.04gm to 4.0gm) before LL-37 instillation and before sacrifice. Inflammation and fibrosis were evaluated using tissue myeloperoxidase (MPO) concentration, collagen content, gross inspection, and microscopic histologic examination. RESULTS: SAGE GM-0111 reduced pain in treated animals significantly (54 ± 32% response rate) in animals exposed to LL-37 insult (96 ± 7% response rate, p<0.001) at 1g of stimulation. Collagen content, gross anatomy, histology with H&E and Masson’s trichrome staining indicated that fibrosis did not occur over the duration of the study. At the time of sacrifice there was no significant variation in tissue inflammation between groups. CONCLUSIONS: LL-37-induced cystitis yielded pain to be independent of inflammation. These findings further substantiate the physiological applicability of the LL-37-induced cystitis model to mimic human IC/PBS pathophysiology. Finally, our SAGE compound demonstrated potent non-opioid analgesic effects within this surrogate model. Source of Funding: NIH NIDDK R01 DK100868 (SO), Primary Children’s Hospital Integrated Science Award (SO), NIH K12 UL1RR025764 (SO), National Science Foundation Graduate Research Fellowship 1256065 (MMJ) © 2020 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 203Issue Supplement 4April 2020Page: e97-e97 Advertisement Copyright & Permissions© 2020 by American Urological Association Education and Research, Inc.MetricsAuthor Information Austin Schults* More articles by this author Wanjian Jia More articles by this author M. Martin Jensen More articles by this author Glenn Prestwich More articles by this author Siam Oottamasathien More articles by this author Expand All Advertisement PDF downloadLoading ...

Catalytic hydrogenolysis of lignin β-O-4 aryl ether compound and lignin to aromatics over Rh/Nb2O5 under low H2 pressure

The increasing risk of fossil fuels depletion due to surging energy demand has accelerated the search of alternative renewable sources. Lignin, one of the major components of lignocellulosic biomass, is the only abundant renewable natural resource for aromatic compounds. In this work, the effects of metals and process parameters were discussed via the catalytic hydrogenolysis of β-O-4 lignin model compound, 2-phenethyl phenyl ether. The best results were obtained over Rh/Nb2O5 with an overall conversion of 99.3% and exceptional selectivity of 98.9% to aromatic products when the hydrogenolysis was carried out at 260 °C and 0.1 MPa H2 for 4 h. The high efficiency is mainly attributed to the cooperation between Rh and NbOx at the perimeter sites, in which Rh particles are responsible for the dissociation of H2 and NbOx for activating CO bonds. With respect to depolymerize of ash wood lignin, the liquid products were mostly aromatics over Rh/Nb2O5 under 0.1 MPa H2. The results achieved in this work provide a promising prospect towards valorization of lignin into production of valuable aromatic compounds under low hydrogen pressure.

Bonding of crown ethers to α-zirconium phosphate—Novel layered adsorbent for radioactive strontium separation

Searching for new efficient, selective, and stable, adsorbents for 90Srgenerated in the nuclear fuel cycle remains important. In the last year, 18 crown 6ether and its derivatives have been intensively studied as highly efficient ion-exchangers for removal of 90Sr. However, one of the main problems for further application of these expensive macrocyclic ligands is loss in solid-liquid media due to their solubility. To overcome this problem, in this work, we have developed a new organic – inorganic layer α-ZrP composite by intercalation of 4-amino-benzo-18 crown 6. This new α-ZrP composite (AM-ZrP) not only inherits the advantages of 4-amino-benzo-18 crown 6 and α-ZrP, exhibiting excellent stability under acid and radioactive conditions, but also efficiently decreases the loss of valuable4-amino-benzo-18 crown 6 in the adsorption process. Furthermore, the preparation process for AM-ZrP is simple and it can be easily produced on a large-scale. Remarkably, having a pore size matching4-amino-benzo-18 crown 6, AM-ZrP shows high selectivity for capturing Sr2+ from complicated mixed solutions. The maximum adsorption capacity for Sr2+ onto AM-ZrP is 320.16 mg·g−1, which is about five times that of neat α-ZrP. Itsurpasses most other inorganic adsorbents, which can be attributed to the much higher number of adsorption sites and the wide interlayer spacing of α-ZrP after interactionwith4-amino-benzo-18 crown 6. Our present work not only poses a new way to promote crown ether compounds and α-ZrP materials, furthering their application in nuclear wastewater disposal, but also develops a new way of thinking about the design and preparation of new adsorbents for removal of difficult-to-capture ions from nuclear wastewater.

Draft Genome Sequence of Rhodococcus aetherivorans JCM 14343T, a Bacterium Capable of Degrading Recalcitrant Noncyclic and Cyclic Ethers.

Here, we report the draft genome sequence of Rhodococcus aetherivorans JCM 14343T, which possesses the versatile ability to degrade recalcitrant noncyclic and cyclic ether compounds. The 4.2-Mbp genome of this bacterium contains alkane hydroxylase and propane monooxygenase genes involved in the degradation of noncyclic and cyclic ethers, respectively.

Utilization of Lignin-Derived Small Molecules: Epoxy Polymers from Lignin Oxidation Products.

Much effort has been invested in developing methods for producing small molecules from lignin as a way to source feedstock chemicals from renewable sources. Significant progress is being made, and methods for deconstructing lignin are producing good yields of small, mononuclear aromatic products-sufficient amounts to enable studies of the potential use of these compounds as replacements for compounds currently produced from petroleum. To investigate the use of lignin products in epoxies, we begin with aromatic acids that can be produced from lignin, treat them with epichlorohydrin to make glycidyl ethers, and investigate the thermal and mechanical properties of cured mixtures of these compounds with a commercial epoxy resin (EPON 826) and an anhydride curing agent (NMA). While most of the lignin-modified epoxy polymers exhibit good physical and thermal properties, the polymer prepared from p-hydroxybenzoic acid (compound 6) has a higher glass-transition temperature (Tg = 159 °C) than do thermosets made with other lignin-derived materials, such as vanillic acid diglycidyl ether (compound 4) and matches the Tg of cured samples of the commercial EPON-826/NMA epoxy system. This is significant, as p-hydroxybenzoic acid is readily available by simple hydrolysis of several different lignins and functions as a drop-in replacement for 50% of the BPA-based material in this commercial system without significant degradation of material properties. The use of lignin-derived small molecules in high-value systems such as epoxies may help improve the economics of biorefineries.