Category: 539-88-8

Darrah, Kristie published the artcileAllosteres to regulate neurotransmitter sulfonation, Recommanded Product: Ethyl 4-oxopentanoate, the main research area is SULT1A3 allosteric inhibitor catecholamine sulfonation; SULT1A3; allosteric regulation; allostery; catecholamine; dopamine; enzyme inhibitor; enzyme kinetics; enzyme mechanism; enzyme structure; epinephrine; inhibition; mechanism; neurotransmitter; norepinephrine; nuclear magnetic resonance (NMR); serotonin; spin label; sulfotransferase.

Catecholamine neurotransmitter levels in the synapses of the brain shape human disposition – cognitive flexibility, aggression, depression, and reward seeking – and manipulating these levels is a major objective of the pharmaceutical industry. Certain neurotransmitters are extensively sulfonated and inactivated by human sulfotransferase 1A3 (SULT1A3). To our knowledge, sulfonation as a therapeutic means of regulating transmitter activity has not been explored. Here, we describe the discovery of a SULT1A3 allosteric site that can be used to inhibit the enzyme. The structure of the new site is determined using spin-label-triangulation NMR. The site forms a cleft at the edge of a conserved ∼30-residue active-site cap that must open and close during the catalytic cycle. Allosteres anchor into the site via π-stacking interactions with two residues that sandwich the planar core of the allostere and inhibit the enzyme through cap-stabilizing interactions with substituents attached to the core. Changes in cap free energy were calculated ab initio as a function of core substituents and used to design and synthesize a series of inhibitors intended to progressively stabilize the cap and slow turnover. The inhibitors bound tightly (34 nm to 7.4μm) and exhibited progressive inhibition. The cap-stabilizing effects of the inhibitors were exptl. determined and agreed remarkably well with the theor. predictions. These studies establish a reliable heuristic for the design of SULT1A3 allosteric inhibitors and demonstrate that the free-energy changes of a small, dynamic loop that is critical for SULT substrate selection and turnover can be calculated accurately.

Journal of Biological Chemistry published new progress about Allosterism. 539-88-8 belongs to class esters-buliding-blocks, name is Ethyl 4-oxopentanoate, and the molecular formula is C7H12O3, Recommanded Product: Ethyl 4-oxopentanoate.

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

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

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

Guo, Qianqian published the artcileLow-cost synthesis of nanoaggregate SAPO-34 and its application in the catalytic alcoholysis of furfuryl alcohol, Recommanded Product: Ethyl 4-oxopentanoate, the main research area is SAPO nanoaggregate furfuryl alc catalytic alcoholysis.

Silicoaluminophosphate-34 (SAPO-34) mol. sieves have important applications in the petrochem. industry as a result of their shape selectivity and suitable acidity. In this work, nanoaggregate SAPO-34 with a large external surface area was obtained by dissolving pseudoboehmite and tetraethylorthosilicate in an aqueous solution of tetraethylammonium hydroxide and subsequently adding phosphoric acid. After hydrolysis in an alk. solution, the aluminum and silicon precursors exist as Al(OH)4- and SiO2(OH)-, resp.; this is beneficial for rapid nucleation and the formation of nanoaggregates in the following crystallization process. Addnl., to study the effect of the external surface area and pore size on the catalytic performance of different SAPO-34 structures, the alcoholysis of furfuryl alc. to Et levulinate (EL) was chosen as a model reaction. In a comparison with the traditional cube-like SAPO-34, nanoaggregate SAPO-34 generated a higher yield of 74.1% of EL, whereas that with cube-like SAPO-34 was only 19.9%. Moreover, the stability was remarkably enhanced for nanoaggregate SAPO-34. The greater external surface area and larger number of external surface acid sites are helpful in improving the catalytic performance and avoiding coke deposition.

Chinese Journal of Catalysis 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, Recommanded Product: Ethyl 4-oxopentanoate.

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

Vaishnavi, B. J. published the artcileUtilization of renewable resources: Investigation on role of active sites in zeolite catalyst for transformation of furfuryl alcohol into alkyl levulinate, SDS of cas: 539-88-8, the main research area is renewable resources zeolite catalyst transformation furfuryl alc alkyl levulinate.

A bio-derived furfuryl alc. transformation into various high-value chems. is a growing field of interest among researchers. This study reports an exclusive investigation of the porosity and active sites responsible for the efficient alcoholysis of furfuryl alc. to alkyl levulinate by the aid of zeolite catalyst. Alkyl levulinate is a promising platform chem. potentially used as a fuel additive and also for the production of chems. A detailed study using well-characterized HZSM-5 catalyst on the influence of acidity and post synthesis modification like desilication, dealumination, metal ion exchange and phosphate modification revealed the most desired type of acid sites required to catalyze this reaction. Among the HZSM-5 catalysts tested, HZSM-5 (SAR 95) showed the best performance of ≥ 99% furfuryl alc. conversion and 85% Bu levulinate selectivity under optimum conditions. The catalyst exhibited good recyclability addnl. addressing all the challenges reported in the previous literature fulfilling the green chem. principles.

Molecular Catalysis 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, SDS of cas: 539-88-8.

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

Wang, Yantao published the artcileMicrowave-assisted catalytic upgrading of bio-based furfuryl alcohol to alkyl levulinate over commercial non-metal activated carbon, HPLC of Formula: 539-88-8, the main research area is activated carbon alcoholysis catalyst furfuryl alc alkyl levulinate microwave.

A cheap and com. available non-metal activated carbon (AC) as an efficient catalyst for the alcoholysis of furfuryl alc. (FA) to alkyl levulinate (AL) under microwave assistance was firstly investigated. The catalyst gave an impressive Me levulinate (ML) yield of 78% in only 5 min at 170 °C in the presence of FA (0.2 M, 3 mL) and AC (100 mg). Various reaction parameters in dependence of time such as temperature, catalyst and feedstock loadings as well as solvent types have been optimized. The re-utilization experiments of the catalyst showed that the activity related to the acidic groups of the catalysts, and the deactivation was due to the leaching of acidic specie, which was easily extracted by the solvent. Note that extremely low concentration of the active species extracted from AC (less than 1 wt %) could also give 62% ML yield. The present study provided a promising way for AL synthesis over cheap, com. available and environmentally benign catalyst.

Molecular Catalysis 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, HPLC of Formula: 539-88-8.

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

Manjunathan, Pandian published the artcileRecognizing soft templates as stimulators in multivariate modulation of tin phosphate and its application in catalysis for alkyl levulinate synthesis, COA of Formula: C7H12O3, the main research area is tin phosphate catalysis alkyl levulinate.

Catalyst synthesis is an art where an inefficient material can be remarkably converted into a highly active and selective catalyst by adopting a suitable synthetic strategy to tune its properties during synthesis. The underlying principle of the strategy presented here is the integration of tailoring the structural and chem. behavior of tin phosphates with tuned catalytic active centers directed by employing different structure directing agents (SDAs) and the attempt to understand this in detail. It is demonstrated how soft templates can be effectively used for their so far unknown utilization of tuning the active sites in phosphate containing catalysts. We found that, by using an appropriate synthesis strategy, it is possible to tune and control explicitly both the catalyst morphol. and the nature of active sites at the same time. The 31P MAS NMR study revealed that employing SDAs in the synthesis strongly influenced the nature and amount of phosphate species in addition to porosity. The resultant different nanostructured SnPO catalysts were investigated for one-pot synthesis of alkyl levulinates via alcoholysis of furfuryl alc. Among the catalysts, SnPO-P123 exhibited greater Bu levulinate yield via alcoholysis of furfuryl alc. with n-butanol and the study was extended to synthesize different alkyl levulinates. Importantly, the active sites in the SnPO-P123 catalyst responsible for the reaction were elucidated by a study using 2,6-lutidine as a basic probe mol. This study therefore provides an avenue for rational design and construction of highly efficient and robust nanostructured SnPO catalysts to produce alkyl levulinates selectively.

Catalysis Science & Technology 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, COA of Formula: C7H12O3.

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