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Although tissue engineering has attracted increasing attention for the treatment of degenerative intervertebral disc disease, the biochemical properties, structural organization, and mechanical characteristics of annulus fibrosus tissue have restricted progress. Differentiation of annulus fibrosus-derived stem cells (AFSCs) can be regulated by the elasticity of substrates such as poly(ether carbonate urethane)urea (PECUU). Decellularized annulus fibrosus matrix (DAFM) has good biocompatibility and biodegradability, making it suitable for cell adhesion, proliferation, and differentiation. In this study, we used a coaxial electrospinning method to synthesize DAFM/PECUU-blended fibrous scaffolds with elasticities approximating that of native inner and outer annulus fibrosus tissue. AFSCs cultured on DAFM/PECUU-blended fibrous scaffolds exhibited increased collagen type I gene expression with increasing elasticity of the scaffold material; notably, collagen type II and aggrecan gene expression exhibited the opposite trend. Regarding extracellular matrix secretion, collagen type I content gradually increased with substrate elasticity, while collagen type II and aggrecan contents decreased. In vivo evaluations employing magnetic resonance imaging, hematoxylin and eosin staining, and immunohistochemistry indicated that DAFM/PECUU-blended fibrous scaffolds could effectively repair defects of annulus fibrosus tissue. Our findings provide a theoretical and practical basis for the development of bionic annulus fibrosus tissue that closely mimics the biological properties, mechanical function, and matrix composition of native tissue.

Although ether-based electrolytes have been extensively applied in anode evaluation of batteries, anodic instability arising from solvent oxidability is always a tremendous obstacle to matching with high-voltage cathodes. Herein, by rational design for solvation configuration, the fully coordinated ether-based electrolyte with strong resistance against oxidation is reported, which remains anodically stable with high-voltage Na3 V2 (PO4 )2 O2 F (NVPF) cathode under 4.5 V (versus Na+ /Na) protected by an effective interphase. The assembled graphite//NVPF full cells display superior rate performance and unprecedented cycling stability. Beyond that, the constructed full cells coupling the high-voltage NVPF cathode with hard carbon anode exhibit outstanding electrochemical performances in terms of high average output voltage up to 3.72 V, long-term cycle life (such as 95 % capacity retention after 700 cycles) and high energy density (247 Wh kg-1 ). In short, the optimized ether-based electrolyte enriches systematic options, the ability to maintain oxidative stability and compatibility with various anodes, exhibiting attractive prospects for application.

By using copper(I) homoenolates as nucleophiles, which are generated through the ring-opening of 1-substituted cyclopropane-1-ols, a catalytic asymmetric allylic substitution with allyl phosphates is achieved in high to excellent yields with high enantioselectivity. Both 1-substituted cyclopropane-1-ols and allylic phosphates enjoy broad substrate scopes. Remarkably, various functional groups, such as ether, ester, tosylate, imide, alcohol, nitro, and carbamate are well tolerated. Moreover, the present method is nicely extended to the asymmetric construction of quaternary carbon centers. Some control experiments argue against a radical-based reaction mechanism and a catalytic cycle based on a two-electron process is proposed. Finally, the synthetic utilities of the product are showcased by means of the transformations of the terminal olefin group and the ketone group.

The realisation of high-performance concrete mixtures requires the use of superplasticizers to achieve a low water/binder ratio and thus high strengths. Polycarboxylate ethers (PCE) are mostly used as superplasticizers. The effectiveness of these superplasticizers depends on their chemical structure, the binders' alkaline environment and the ions present in the pore solution of the binder. In high alkaline systems like some alkali-activated materials no effective superplasticizer have been found yet. To unravel the compatibility of certain PCE to such a highly alkaline system a fluorescence microscopy approach was used. In first experiments, the adsorption of APEG (allyl ether) and MPEG (methacrylate) PCE on ground granulated blast furnace slag and fly ash was investigated varying the concentration of the activators. At a certain concentration, a complexation of the PCE can be recognised in fluorescence microscope. APEG shows a better stability compared to MPEG; this correlates with rheological investigations.

The development of small molecule inhibitors of programmed cell death-1/programmed cell death-ligand 1 (PD-1/PD-L1) has drawn research interest for the treatment of cancer. Recently, we reported the discovery of a novel dimeric core small molecule PD-1/PD-L1 inhibitor. In an effort to discover more potent inhibitors, we further explored the dimeric core scaffold. Our investigations of the structure-activity-relationship revealed that introduction of lipophilic substituents onto one of the di-alkoxylated phenyl rings improved binding affinities to PD-L1, and inhibitory activities of PD-1/PD-L1 in cellular assays. Furthermore, conversion of the ether linker part to an olefin linker not only improved binding affinity but also led to slow dissociation binding kinetics. We also explored more potent, as well as downsized, scaffolds. Compounds bearing a linear chain in place of one of the di-alkoxylated phenyl rings exhibited good binding affinity with improved ligand efficiency (LE). Representative compounds demonstrated potent inhibitory activities of PD-1/PD-L1 in the submicromolar range in cellular assays as well as cellular function in the mixed lymphocyte reaction (MLR) assay with efficacy comparable to anti-PD-1 antibody. Our results provide applicable information for the design of more potent inhibitors targeting PD-1/PD-L1 pathway.

The physicochemical properties of room temperature ionic liquids (RTILs) consisting of bis(trifluoromethanesulfonyl)amide (TFSA- ) combined with 1-hexyl-1-methylpyrrolidinium (Pyr1,6 + ), 1-(butoxymethyl)-1-methylpyrrolidinium (Pyr1,1O4 + ), 1-(4-methoxybutyl)-1-methyl pyrrolidinium (Pyr1,4O1 + ), and 1-((2-methoxyethoxy)methyl)-1-methylpyrrolidinium (Pyr1,1O2O1 + ) were investigated using both experimental and computational approaches. Pyr1,1O2O1 TFSA, which contains two ether oxygen atoms, showed the lowest viscosity, and the relationship between its physicochemical properties and the position and number of the ether oxygen atoms was discussed by a careful comparison with Pyr1,1O4 TFSA and Pyr1,4O1 TFSA. Ab initio calculations revealed the conformational flexibility of the side chain containing the ether oxygen atoms. In addition, molecular dynamics (MD) calculations suggested that the ion distributions have a significant impact on the transport properties. Furthermore, the coordination environments of the Li ions in the RTILs were evaluated using Raman spectroscopy, which was supported by MD calculations using 1000 ion pairs. The presented results will be valuable for the design of functionalized RTILs for various applications.

Feroniellin analogs isolated from Feroniella lucida possess a furanocoumarin skeleton connected to monoterpenic five- to seven-membered ethereal rings by an ether linkage and exhibit a broad spectrum of biological activities. In this contribution, we intended to establish a "ring-size-divergent" synthetic strategy for the monoterpenic five- to seven-membered ethereal rings through the chemical sythesis of feroniellins. The short and comprehensive synthesis of feroniellins was achieved in only two steps from easily available bergamottin based on the "ring-size-divergent" strategy. In addition, these syntheses resulted in revision of the proposed structures for feroniellins A and B and the determination of all the absolute configurations of feroniellins; their preliminary anti-inflammatory activities were investigated as well.

The chemical identification of Cannabis is commonly carried out using the Duquenois-Levine (DL) colorimetric test. On the other hand, its active substances called cannabinoids are differentiated by thin-layer chromatography (TLC). This work aims to optimize parameters of these two chemical tests using different samples of Cannabis in natura and previously heated (decarboxylated), as well as their isolated bioactive and possible false positives. The efficiency of the DL test without using ether and aliphatic aldehyde was evaluated, comparing the removal or not of the solid sample from the reaction medium after applying different concentrations of the vanillin ethanolic solution. The chemical properties of different cannabinoids and solvents were estimated and correlated with the TLC retention factors. DL tests applied directly to the plant matrix did not show the expected color, even using a high concentration of vanillin. However, obtaining ethanolic extracts from the samples using low vanillin concentration was sufficient without detecting false positives described in the literature. Cannabinoids with high dipole moment ( μ ) were poorly eluted in TLC, indicating a great interaction with the stationary phase. Their identifications could be conducted based on their distinct lipophilic characteristics ( log P OW ) and the choice of a more polar solvent mix ( μ mix ). It is concluded that the DL test can be conducted with reagents of less toxicity, but it is necessary to remove the plant matrix from the reaction medium. The correlation of the TLC results with the chemical properties of cannabinoids and solvents was consistent and can be extrapolated for more complex analyses.

A novel visible light‐induced oxidant‐free and metal‐free cascade cyclization of 2‐isocyanoaryl thioethers with ethers has been established, which provides an expeditious approach to access ether‐functionalized benzothiazoles in acceptable to good yields. The obtained products combine benzothiazole with ether and represent key structural motifs of a large of biologically active molecules in medicinal chemistry.

The lithium-sulfur (Li-S) battery is regarded as a promising secondary battery. However, constant parasitic reactions between the Li anode and soluble polysulfide (PS) intermediates significantly deteriorate the working Li anode. The rational design to inhibit the parasitic reactions is plagued by the inability to understand and regulate the electrolyte structure of PSs. Herein, the electrolyte structure of PSs with anti-reductive solvent shells was unveiled by molecular dynamics simulations and nuclear magnetic resonance. The reduction resistance of the solvent shell is proven to be a key reason for the decreased reactivity of PSs towards Li. With isopropyl ether (DIPE) as a cosolvent, DIPE molecules tend to distribute in the outer solvent shell due to poor solvating power. Furthermore, DIPE is more stable than conventional ether solvents against Li metal. The reactivity of PSs is suppressed by encapsulating PSs into anti-reductive solvent shells. Consequently, the cycling performance of working Li-S batteries was significantly improved and a pouch cell of 300 Wh kg-1 was demonstrated. The fundamental understanding in this work provides an unprecedented ground to understand the electrolyte structure of PSs and the rational electrolyte design in Li-S batteries.

International audience; These last decades, it has been widely assumed that 18-crown-6-ether (CE) plays a spectator role during the chemical processes occurring in isolated host-guest complexes between peptides or proteins and CE, after activation in mass spectrometers. Our present experimental and theoretical results challenge this hypothesis by showing that CE can abstract a proton or a protonated molecule from protonated peptides after activation by collisions in argon or electron capture/transfer. Furthermore, thanks to comparison between experimental and calculated values of collision cross-sections, we demonstrate that CE can change binding site after electron transfer. We also propose detailed mechanisms for these processes.

Herein, we describe the development of a deconstructive strategy for the first asymmetric synthesis of (−)-thebainone A, capitalized on an enantioselective C−C bond activation and a C−O bond cleavage reaction. The Rh-catalyzed asymmetric ‘cut-and-sew’ transformation between sterically hindered trisubstituted alkenes and benzocyclobutenones allows efficient construction of the fused A/B/C rings and the all-carbon quaternary center of the natural product. The newly optimized conditions show a broad substrate scope and excellent enantioselectivity (up to 99.5:0.5 er). Taking advantage of the boron-mediated ether bond cleavage, synthesis of the morphine-alkaloid (−)-thebainone A has been completed with two complementary routes.

Aqueous rechargeable zinc metal batteries promise attractive advantages including safety, high volumetric energy density, and low cost; however, such benefits cannot be unlocked unless Zn reversibility meets stringent commercial viability. Herein, we report remarkable improvements on Zn reversibility in aqueous electrolytes when phosphonium-based cations are used to reshape interfacial structures and interphasial chemistries, particularly when their ligands contain an ether linkage. This novel aqueous electrolyte supports unprecedented Zn reversibility by showing dendrite-free Zn plating/stripping for over 6400 h at 0.5 mA cm-2 , or over 280 h at 2.5 mA cm-2 , with coulombic efficiency above 99 % even with 20 % Zn utilization per cycle. Excellent full cell performance is demonstrated with Na2 V6 O16 ⋅1.63 H2 O cathode, which cycles for 2000 times at 300 mA g-1 . The microscopic characterization and modeling identify the mechanism of unique interphase chemistry from phosphonium and its functionalities as the key factors responsible for dictating reversible Zn chemistry.

Selectivity of aryl iodo over ethynyl iodo toward the Suzuki cross coupling reaction is explored by utilizing a palladium complex of amino-ether heteroditopic macrobicycle. Subsequently, unreacted ethynyl iodide undergoes homocoupling reaction in the same catalytic atmosphere, thereby representing a cascade dual C-C coupling reaction. Furthermore, this approach is extended for novel one-pot synthesis of unsymmetrical 1,3-diynes.

As a novel Sanger‐type reagent, 2‐fluoro‐5‐nitrophenyldiazonium tetrafluoroborate enabled the versatile functionalization of primary and secondary aliphatic alcohols. Based on a mild nucleophilic aromatic substitution of the fluorine atom under unprecedented, base‐free conditions, the diazonium unit on the aromatic core of the resulting aryl‐alkyl ether could be employed for such diverse transformations as radical C−H activation and cyclization, as well as palladium catalyzed cross‐coupling reactions., In with the new: In contrast to established Sanger reagents, 2‐fluoro‐5‐nitrophenyldiazonium enables the functionalization of primary and secondary aliphatic alcohols without base‐mediated activation. As an additional and unique advantage, the diazonium unit offers manifold options for further functionalization including radical C−H activation in the aliphatic side chain, radical arylation, as well as various types of palladium catalyzed cross‐couplings.

Two series of 1,1'-biphenyl analogues with various leaving groups (L = OAc, OCH 3 , OCHCH=CH 2 , OCH 2 Ph, SPh, SePh, and Ph 3 P + ) were synthesized. Their reactivity towards DNA and the reaction mechanism were investigated by determining DNA interstrand cross-link (ICL) efficiency, radical and carbocation formation, and the cross-linking reaction sites. All compounds induced DNA ICL formation upon 350 nm irradiation via a carbocation that was generated from oxidation of the corresponding free radicals. The ICL efficiency and the reaction rate strongly depend on the combined effect of the leaving group and the substituent. Among all compounds tested, the high ICL efficiency (30-43%) and fast reaction rate were observed with compounds carrying a nitrophenyl group and acetate ( 2a) , ether ( 2b and 2c) , or triphenylphosphonium salt ( 2g ) as leaving groups. Most compounds with a 4-methoxybenzene group showed similar DNA ICL efficiency (∼ 30%) with a slow DNA cross-linking reaction rate. Both cation trapping and free radical trapping adducts were detected in the photo activation process of these compounds, which provided direct evidence for the proposed mechanism. Heat stability study in combination with sequence study suggested that these photo-generated benzyl cations alkylate DNA at dG, dA, and dC sites.

In this study, the performance of ofloxacin (OFX) degradation in synthetic wastewater using synthesized MnOx -CeOx /γ-Al2 O3 as a heterogeneous ozonation catalyst was evaluated. The removal rates of OFX and chemical oxygen demand (COD) during 15-day continuous-flow experiments were 98.2% and 76.7% on average, respectively. An ozone index (mgCOD/mgO3 ) of 1.09 with a high ozone utilization efficiency of 91.39% was achieved. The pseudo-first-order rate constant of ofloxacin degradation reached 15.216 × 10-2 min-1 , which was five times that (3.085 × 10-2 min-1 ) without catalysts. The results of gas chromatography-mass spectrometry (GC-MS) demonstrated that a variety of small-molecule organics occurred in the final oxidation products, such as 4-hydroxyl-4-methyl-2-pentanone and 2-oxoadipic acid in addition to homologs of OFX. The results of this study suggested that hydroxyl radicals played critical roles in the degradation and mineralization of OFX via four main pathways: (a) electrophilic addition of nitrogen; (b) breakdown of carbon-carbon double bonds; (c) hydrolysis of ether rings; and (d) halodecarboxylation of carboxyl groups. The biodegradability (BOD5 /COD) of OFX after catalytic ozonation reached 0.54. PRACTITIONER POINTS: Ofloxacin wastewater was treated using catalytic ozonation in a 15-day continuous experiment with MnOx -CeOx /γ-Al2 O3 as a catalyst. The ozone index reached 1.09 mgCOD/mgO3 during ozonation of ofloxacin. The presence of the catalyst increased the reaction rate constant by a factor of five. 4-hydroxy-4-methyl-2-pentanone was the primary ofloxacin oxidation product.

Background Virgin olive oil (VOO) is highly appreciated by its organoleptic features, which can be mainly ascribed to the presence of volatile components with a great chemical diversity. It is well-known that the VOO volatile fraction strongly depends on different aspects that encompass genetic, agronomical, processing and post-processing factors. In this research, we have developed a method for qualitative and semiquantitative determination of volatile components in VOOs subjected to thermal stress by headspace extraction on-line coupled to gas chromatography-mass spectrometry (HS-GC-MS). Results The method has been applied to 100 extra-virgin olive oil (EVOO) samples, which led to identify tentatively 52 volatile components, including 12 alcohols, 17 aldehydes, 3 ketones, 1 ether, 2 furans, 2 carboxylic acids, and 15 hydrocarbons. The method has been used to study the cultivar effect and the main biochemical pathways involved in the synthesis of volatile compounds, with special emphasis on those formed by degradation of unsaturated fatty acids (FAs). Principal Component Analysis (PCA), explaining 76.7% of the total variability, showed that the volatile profile of EVOOs subjected to thermal stress allowed discriminating samples from different cultivars. Conclusion Volatiles detected in EVOOs subjected to thermal stress with highest contribution to discriminate between selected cultivars have been correlated to the concentration of the three main FAs in VOO, namely, oleic, linoleic, and linolenic acids. The FAs profile seems to be especially relevant to explain the concentration of certain volatile compounds with direct incidence on the organoleptic properties. This article is protected by copyright. All rights reserved.

Background Spirodiclofen is a spirocyclic tetronic acid-type acaricidal agent. Nowadays, serious pests resistance to spirodiclofen and cross-resistance to other acaricides has appeared. To overcome pests resistance and discover new potential agrochemicals, a series of ether derivatives were prepared based on spirodiclofen as a lead compound. Their pesticidal activities were investigated against three typically agricultural pests, Mythimna separata Walker, Aphis citricola Van der Goot and Tetranychus cinnabarinus Boisduval. Results Four steric structures of products 5e, 5 f, 5i and 5j were determined by single-crystal X-ray diffraction. Against Tetranychus cinnabarinus, compounds 5b, 5 f and 5 L exhibited potent acaricidal activity, and their good control effects in the glasshouse were observed when compared with spirodiclofen, especially the control efficiency of compound 5b was comparable to that of spirodiclofen; against Mythimna separata, compound 5j showed >1.8-fold potent insecticidal activity of spirodiclofen; against Aphis citricola, compounds 5d and 5j displayed >2.0-fold potent aphicidal activity of spirodiclofen. The relationships between their structures and agricultural activities were also discussed. Conclusion Compounds 5b and 5d could be further studied as acaricidal and aphicidal agents, respectively; compound 5j can be considered as a lead compound for the insecticidal and aphicidal activities. This will pave the way for future application of these derivatives as pesticide substitutes for spirodiclofen. This article is protected by copyright. All rights reserved.

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.

Lithium-ion batteries with routine carbonate electrolytes cannot exhibit satisfactory fast-charging performance and lithium plating is widely observed at low temperatures. Herein we demonstrate that a localized high-concentration electrolyte consisting of 1.5 M lithium bis(fluorosulfonyl)imide in dimethoxyethane with bis(2,2,2-trifluoroethyl) ether as the diluent, enables fast-charging of working batteries. A uniform and robust solid electrolyte interphase (SEI) can be achieved on graphite surface through the preferential decomposition of anions. The established SEI can significantly inhibit ether solvent co-intercalation into graphite and achieve highly reversible Li+ intercalation/de-intercalation. The graphite | Li cells exhibit fast-charging potential (340 mAh g-1 at 0.2 C and 220 mAh g-1 at 4 C), excellent cycling stability (ca. 85.5 % initial capacity retention for 200 cycles at 4 C), and impressive low-temperature performance.

Enyne monomers derived from D-xylose underwent living cascade polymerizations to prepare new polymers with a ring-opened sugar and degradable linkage incorporated into every repeat unit of the backbone. Polymerizations were well-controlled and had living character, which enabled the preparation of high molecular weight polymers with narrow molecular weight dispersity values and a block copolymer. By tuning the type of acid-sensitive linkage (hemi-aminal ether, acetal, or ether functional groups), we could change the degradation profile of the polymer and the identity of the resulting degradation products. For instance, the large difference in degradation rates between hemi-aminal ether and ether-based polymers enabled the sequential degradation of a block copolymer. Furthermore, we exploited the generation of furan-based degradation products, from an acetal-based polymer, to achieve the release of covalently bound reporter molecules upon degradation.