Category: esters-buliding-blocks

Li, Shan published the artcileProbiotic potential of γ-aminobutyric acid (GABA)-producing yeast and its influence on the quality of cheese, Computed Properties of 123-29-5, the main research area is yeast aminobutyric acid probiotic potential cheese quality; aroma; physical and chemical indicators; probiotic; yeast; γ-aminobutyric acid (GABA).

Kazakh cheese is a traditional dairy product in Xinjiang, China. To study the function and potential probiotic characteristics of yeast in Kazakh cheese and its contribution to cheese fermentation, we screened the γ-aminobutyric acid (GABA)-producing yeasts Pichia kudriavzevii 1-21, Kluyveromyces marxianus B13-5, Saccharomyces cerevisiae DL6-20, and Kluyveromyces lactis DY1-10. We investigated the potential probiotic properties of these strains and their use in cheese fermentation (cheeses designated CSP, CSM, CSS, and CSI, resp.); a control with no added yeast was designated CS. The results showed that the 4 yeast strains all showed high self-polymerization (2- and 24-h autoaggregation capacity of >80 and 90%, resp.), hydrophobicity (40-92% variation, low hydrophobicity in xylene, but within the range of probiotics), and the ability to survive the gastrointestinal tract (survival rate >75% after simulation), indicating the probiotic ability of the strains in vitro. The GABA production capacity of the CSM cheese increased (to 95.6 mg/100 g), but its protein content did not change significantly, and amino acid degradation was obvious. The GABA production capacity of the CSS cheese decreased (to 450 mg/kg); its protein content declined, and its amino acid content increased. Except for water and protein, we found no obvious differences in most phys. and chem. indicators. Kluyveromyces marxianus B13-5 helped to form the desired texture. Multivariate statistical anal. showed that fermentation of the cheese with the 4 yeasts improved the production of esters and alcs. The CSS cheese had good aroma production performance, because S. cerevisiae DL6-20 produced high concentrations of isoamyl alc., hexanoic acid Et ester, benzyl alc., octanoic acid Et ester, 3-hydroxy-2-butanone, and hexanoic acid; the content of 2-methyl-propanoic acid was low. Compared with the CSP cheese, the CSI and CSM cheeses had a fruitier aroma and a milder odor, but the CSI and CSM cheeses had high concentrations of Et acetate, butanoic acid, Et ester, 3-methyl-1-butanol-acetate, Et hexanoate, Et octanoate, acetic acid 2-phenylethyl ester, and Et lactate; concentrations of 3-methyl-butanoic acid, propanoic acid, acetic acid, and butanoic acid were low. The CSP cheese had stronger acid-producing ability. The order of fragrance production performance was CSS > CSI, CSM > CSP > CS. Research into the fermentation mechanisms of GABA-producing yeast in cheese will provide a theor. basis for the quality control and industrial production of Kazakh cheese.

Journal of Dairy Science published new progress about Aggregation. 123-29-5 belongs to class esters-buliding-blocks, name is Ethyl nonanoate, and the molecular formula is C11H22O2, Computed Properties of 123-29-5.

Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics

Kumar, Ravi published the artcileOxygen and Drug-Carrying Periodic Mesoporous Organosilicas for Enhanced Cell Viability under Normoxic and Hypoxic Conditions, Computed Properties of 2044-85-1, the main research area is melanoma hypoxia oxygen mesoporous organosilica cell viability; drug delivery; hybrid materials; nanostructured materials; oxygen-carrying materials.

Over the last decade, inorganic/organic hybrids have been exploited for oxygen-carrying materials and drug delivery. Its low-cost synthesis, controlled shape and size, and stability have made it a viable delivery strategy for therapeutic agents. Rutin (quercetin-3-O-rutinoside) is a bioflavonoid found in fruits and vegetables. Rutin has a variety of pharmaceutical applications, but its low water solubility reduces its stability and bioavailability. As a result, we introduce a new and stable nanosystem for loading a low-soluble drug (rutin) into oxygen-carrying periodic mesoporous organosilicas (PMO-PFCs). Over the course of 14 days, this nanosystem provided a sustained oxygen level to the cells in both normoxic and hypoxic conditions. At different pH values, the drug release (rutin) profile is also observed Furthermore, the rutin-coated PMO-PFCs interacted with both healthy and malignant cells. The healthy cells have better cell viability on the rutin-coated oxygen-carrying PMO-PFCs, while the malignant cells have a lower cell viability.

International Journal of Molecular Sciences published new progress about Aggregation. 2044-85-1 belongs to class esters-buliding-blocks, name is 2′,7′-Dichloro-3-oxo-3H-spiro[isobenzofuran-1,9′-xanthene]-3′,6′-diyl diacetate, and the molecular formula is C24H14Cl2O7, Computed Properties of 2044-85-1.

Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics

Jangizehi, Amir published the artcileDynamics of supramolecular associative polymer networks at the interplay of chain entanglement, transient chain association, and chain-sticker clustering, Product Details of C16H30O2, the main research area is dynamic supramol associative polymer network interplay chain entanglement sticker.

The dynamic mech. properties of supramol. associative polymer networks depend on the average number of entanglements along the network-forming chains, Ne, and on their content of associative groups, f. In addition, there may be further influence by aggregation of the associative groups into clusters, which, in turn, is influenced by the chem. structure of these groups, and again by Ne and f of the polymer. Therefore, the effects of these parameters are interdependent. To conceptually understand this interdependency, we study model networks in which (a) Ne, (b) f, and (c) the chem. structure of the associative groups are varied systematically. Each network is probed by rheol. The clustering of the associative groups is assessed by analyzing the rheol. data at the end range of frequency covered and by comparison of the number of supramol. network junctions with the maximum possible number of binary transient bonds. We find that if the total number of the network junctions, which can be formed either by interchain entanglement or by interchain transient associations, is greater than a threshold of 13, then the likelihood of cluster formation is high and the dynamics of supramol. associative polymer networks is mainly controlled by this phenomenon. © 2019 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2019.

Journal of Polymer Science, Part B: Polymer Physics published new progress about Aggregation. 142-90-5 belongs to class esters-buliding-blocks, name is Dodecyl 2-methylacrylate, and the molecular formula is C16H30O2, Product Details of C16H30O2.

Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics

Reuter, Hans published the artcileGuanosine nucleolipids: Synthesis, characterization, aggregation and X-Ray crystallographic identification of electricity-conducting G-ribbons, Safety of Ethyl 4-oxopentanoate, the main research area is glioblastoma cytotoxic guanosine nucleolipid synthesis aggregation crystallog; cytotoxic activity; drug profiling; glioblastoma; guanosine; nucleolipids; self-assembly; synthesis design.

The lipophilization of β-D-riboguanosine (1) with various sym. as well as asym. ketones is described (→3a-3f). The formation of the corresponding O-2′,3′-ketals is accompanied by the appearance of various fluorescent byproducts which were isolated chromatog. as mixtures and tentatively analyzed by ESI-MS spectrometry. The mainly formed guanosine nucleolipids were isolated and characterized by elemental analyses, 1H-, 13C-NMR and UV spectroscopy. For a drug profiling, static topol. polar surface areas as well as 10logPOW values were calculated by an increment-based method as well as exptl. for the systems 1-octanol-H2O and cyclohexane-H2O. The guanosine-O-2′,3′-ketal derivatives 3b and 3a could be crystallized in (D6)DMSO – the latter after one year of standing at ambient temperature X-ray anal. revealed the formation of self-assembled ribbons consisting of two structurally similar 3b nucleolipid conformers as well as integrated (D6)DMSO mols. In the case of 3a · DMSO, the ribbon is formed by a single type of guanosine nucleolipid mols. The crystalline material 3b · DMSO was further analyzed by differential scanning calorimetry (DSC) and temperature-dependent polarization microscopy. Crystallization was also performed on interdigitated electrodes (Au, distance, 5μm) and visualized by SEM. Resistance and amperage measurements clearly demonstrate that the electrode-bridging 3b crystals are elec. conducting. All O-2′,3′-guanosine ketals were tested on their cytostatic/cytotoxic activity towards phorbol 12-myristate 13-acetate (PMA)-differentiated human THP-1 macrophages as well as against human astrocytoma/oligodendroglioma GOS-3 cells and against rat malignant neuroectodermal BT4Ca cells.

Chemistry & Biodiversity published new progress about Aggregation. 539-88-8 belongs to class esters-buliding-blocks, name is Ethyl 4-oxopentanoate, and the molecular formula is C7H12O3, Safety of Ethyl 4-oxopentanoate.

Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics

Ohshio, Maho published the artcileSelf-association behavior of cell membrane-inspired amphiphilic random copolymers in water, Category: esters-buliding-blocks, the main research area is amphiphilic random copolymer RAFT polymerization self association; RAFT; amphiphilic copolymer; hydrophobic interaction; phosphorylcholine.

Water-soluble and amphiphilic random copolymers (P(MPC/DMAx)) composed of hydrophilic 2-methacryloyloxyethyl phosphorylcholine (MPC) and hydrophobic n-dodecyl methacrylate (DMA) were prepared via reversible addition-fragmentation chain transfer (RAFT) controlled radical polymerization The compositions of DMA unit (x) in the copolymer were in the range of 0 to 38 unit mol %.The d.p. of P(MPC/DMAx) was adjusted to about 200. Since the monomer reactivity ratios of MPC and DMA are 1.01 and 1.00, resp., ideal free radical copolymerization occurred. In aqueous solutions, interpolymer aggregation occurred due to the hydrophobic pendant n-dodecyl groups. The aggregation number (Nagg) increased with an increasing x. The mobilities of the DMA and MPC pendant groups in aqueous solutions were restricted, as confirmed by 1H NMR relaxation time measurements, because a part of the MPC units were trapped in the hydrophobic microdomain formed from the pendant n-dodecyl groups. The polarity of the hydrophobic microdomain formed from P(MPC/DMA38) in water was similar to that of Et acetate according to fluorescence probe experiments No specific interactions were found in water between P(MPC/DMAx) and bovine serum albumin because the surface of the interpolymer aggregates contained only hydrophilic MPC units.

Polymers (Basel, Switzerland) published new progress about Aggregation. 142-90-5 belongs to class esters-buliding-blocks, name is Dodecyl 2-methylacrylate, and the molecular formula is C16H30O2, Category: esters-buliding-blocks.

Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics

Fan, Mengjiao published the artcileInfluence of solvent on aggregation of metallic Cu in Cu/MgO during hydrogenation in liquid phase, Formula: C7H12O3, the main research area is copper magnesium oxide catalyst ethyl levulinate hydrogenation solvent.

Cu/MgO catalysts generally could selectively hydrogenate C=O in unsaturated aldehydes, but they often suffer from aggregation of Cu species in liquid-phase reactions. In this study, structural change of Cu/MgO catalyst was investigated during the catalyzing conversion of Et levulinate (EL) to γ-valerolactone (GVL) and 1,4-pentanediol (1,4-PDO) in varied medium. Water as medium could achieve GVL yield of ca. 99%, while ethanol promoted ring-opening of GVL to 1,4-PDO. However, water and ethanol impacted structure of Cu/MgO in distinct ways. Water led to transformation of MgO into Mg(OH)2, destroying interaction of metallic Cu species with MgO. This led to the increase of Cu (111) crystal planes size by ca. 300% and Cu (220) crystal planes size by ca. 200%. The use of water-ethanol as reaction medium further enhanced aggregation of Cu species. Morphol. of the Cu/MgO catalyst changed to rope-like structure and abundant addnl. meso to large pores were created in water or ethanol-water medium. In comparison, ethanol as medium alone suppressed aggregation of metallic Cu and formation of Mg(OH)2, but re-structure of MgO by enlarging pore size also occurred. The aprotic reaction medium such as acetone, THF and N,N-DMF also affected aggregation of metallic Cu species in different ways.

Molecular Catalysis published new progress about Aggregation. 539-88-8 belongs to class esters-buliding-blocks, name is Ethyl 4-oxopentanoate, and the molecular formula is C7H12O3, Formula: C7H12O3.

Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics

Shin, Isaac published the artcileViscosifying a Noncovalently Joined Polymer Nanoparticle Solution upon Heating, Formula: C16H30O2, the main research area is hydrogen bond polymethacrylate nanoparticle solution heating aggregation.

We report the synthesis of a series of statistical terpolymer poly[(Me methacrylate)-co-lauryl methacrylate-co-2-((3,5-bis(4-carbamoyl-3-(trifluoromethyl)phenoxy)benzyloxy)carbonylamino)ethyl methacrylate] (P(MMA-co-LMA-co-BMA)) by reversible addition-fragmentation chain transfer polymerization and their aggregation behaviors in solution In toluene, the solution behavior of terpolymer was controlled by the molar fractions of lauryl methacrylate (LMA) and benzamide-containing methacrylate (BMA) in the polymer, which increased solubility and promoted hydrogen bonding between the primary aromatic amides, resp. Temperature-dependent 1H NMR spectroscopy also indicated gradual dissociation of the hydrogen bonds with increasing temperature For the polymer containing 2.7 mol % of LMA and 2.7 mol % of BMA repeating units, we demonstrated that dissolving the polymer in THF as a good solvent and switching the solvent with toluene produced polymer nanoparticles with diameters of several tens of nanometers, as observed by dynamic light scattering. Intramol. hydrogen bonding was dominant and induced the noncovalent chain collapse. When the temperature of the particle dispersion in toluene at a concentration > 30 mg/mL was increased from RT to 50°C, a significant increase in viscosity was observed This behavior was not observed in a toluene solution of poly(Me methacrylate), which showed decreased viscosity at a higher temperature The viscosity increase was accompanied by a decrease in the particle size, and both were attributed to the dissociation of some intramol. hydrogen bonds within the particles, which can increase the number of individual chains in toluene and result in more intermol. interactions.

Macromolecules (Washington, DC, United States) published new progress about Aggregation. 142-90-5 belongs to class esters-buliding-blocks, name is Dodecyl 2-methylacrylate, and the molecular formula is C16H30O2, Formula: C16H30O2.

Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics

Zhou, Lipeng published the artcileConversion of recalcitrant cellulose to alkyl levulinates and levulinic acid via oxidation pretreatment combined with alcoholysis over Al2(SO4)3, Computed Properties of 539-88-8, the main research area is cellulose oxidation aluminum sulfate catalyst alcoholysis alkyl levulinate.

Conversion of cellulose to chems. is an economic and environmental route for biomass utilization. In this work, efficient conversion of cellulose to alkyl levulinates and levulinic acid was realized by oxidation pretreatment combined with alcoholysis over Al2(SO4)3 catalyst. Proper pre-oxidation conditions including oxidation temperature and time are important. By pre-oxidation, part of hydroxymethyl groups on cellulose was converted to carboxyl groups which provide the Bronsted acid sites near the glycosidic bonds to improve the depolymerization of cellulose to monosaccharide. Al2(SO4)3·18H2O can play both Bronsted and Lewis acid roles in methanol and catalyze the conversion of monosaccharide to alkyl levulinates and levulinic acid. After pre-oxidation at optimized conditions, cellulose can be converted into Me levulinate and levulinic acid over Al2(SO4)3 in methanol efficiently, and total yield of Me levulinate and levulinic acid can reach 66.8% at 180°C for 3 h. Furthermore, the simple and cheap Al2(SO4)3 catalyst is recyclable which is important for the practical application.

Cellulose (Dordrecht, Netherlands) published new progress about Alcoholysis. 539-88-8 belongs to class esters-buliding-blocks, name is Ethyl 4-oxopentanoate, and the molecular formula is C7H12O3, Computed Properties of 539-88-8.

Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics

Zhai, Peng published the artcileEfficient Production of Ethyl Levulinate from Furfuryl Alcohol Catalyzed by Modified Zirconium Phosphate, Category: esters-buliding-blocks, the main research area is ethyl levulinate furfuryl alc zirconium phosphate catalyst property.

The catalytic activities of various solid acid catalysts were investigated via the reaction of the direct alcoholysis from furfuryl alc. to Et levulinate. The modified zirconium phosphate with sulfuric acid, prepared via a sol-gel method, exhibited excellent catalytic performance. By controlling the S/Zr mole ratio of 0.5 at the catalyst preparation, the modified zirconium phosphate catalyst obtained catalytic activity of 97.8% EL yield and 100% FA conversion. The mechanism of enhancing catalytic activity of modified zirconium phosphate was investigated. Owing to the higher sp. surface area and more Lewis and Bronsted acid sites, the modified zirconium phosphate catalyst displayed higher catalytic activity in comparison to unmodified zirconium phosphate. In addition, the modified zirconium phosphate catalyst was suitable for a broad temperature range. This modification method can provide a new way to enhance Lewis and Bronsted acidity of zirconium phosphate by adjusting S/Zr ratio rather than the P/Zr ratio.

ChemistrySelect published new progress about Alcoholysis. 539-88-8 belongs to class esters-buliding-blocks, name is Ethyl 4-oxopentanoate, and the molecular formula is C7H12O3, Category: esters-buliding-blocks.

Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics

Zhang, Luxin published the artcileCatalytic conversion of carbohydrates into 5-ethoxymethylfurfural using γ-AlOOH and CeO2@B2O3 catalyst synergistic effect, Safety of Ethyl 4-oxopentanoate, the main research area is carbohydrate ethoxymethylfurfural catalytic conversion boehmite cerium boron oxide catalyst.

Selective catalytic conversion of carbohydrates to 5-ethoxymethylfurfural (EMF) is a critical approach to the biorefinery. In this work, solid acid catalysts of γ-AlOOH and CeO2@B2O3 were used to convert carbohydrates to EMF in a one-pot process, performed in an ethanol/DMSO solvent system. The synergistic effect of γ-AlOOH and CeO2@B2O3 was studied. Furthermore, the morpho-structural properties of the catalysts were characterized, and the effects of reaction time, reaction temperature, catalyst load, and the amount of cosolvent on the conversion of glucose to EMF were examined and optimized. Under the reaction conditions of 170 °C for 20 h, glucose, sucrose, cellobiose, inulin and starch were used as raw materials, and the EMF yield range was 9.2-27.7%. The results showed that the synergistic effect of γ-AlOOH and CeO2@B2O3 further causes the combination of multiple acid sites with different types and strength distributions. Particularly, the collaboration between weak, medium-strong, and strong acid, as well as between Lewis and Bronsted acidity, is of great significance for EMF generation. The reusability experiments showed that the combined catalytic system was easily separated and maintained catalytic activity for five successive reactions without further intermediate regeneration steps. This work provides a promising route for the catalytic conversion of biomass-derived carbohydrates into EMF.

RSC Advances published new progress about Alcoholysis. 539-88-8 belongs to class esters-buliding-blocks, name is Ethyl 4-oxopentanoate, and the molecular formula is C7H12O3, Safety of Ethyl 4-oxopentanoate.

Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics