Category: 539-88-8

Wang, Dong-Hao published the artcileAsymmetric Reductive Amination of Structurally Diverse Ketones with Ammonia Using a Spectrum-Extended Amine Dehydrogenase, Application of Ethyl 4-oxopentanoate, the main research area is asym reductive amination reductive engineered amine dehydrogenase.

Amine dehydrogenase-catalyzed reductive amination of prochiral ketones with ammonia is a promising method for the synthesis of optically pure amines in the pharmaceutical and fine chem. industries. However, previously reported amine dehydrogenases show restricted catalytic capacity toward bulky ketones, which limits their widespread applications toward the production of chiral amines. Herein, we expanded the substrate scope of an engineered amine dehydrogenase GkAmDH from Geobacillus kaustophilus via laboratory evolution for the reductive amination of an extensive set of ketones. Several beneficial mutants were identified with a up to 2.2 U mg-1 activity toward bulky benzylacetone, 110-fold higher than that of M0. Using the engineered M3 and M8, structurally diverse bulky chiral amines could be synthesized with up to >99% conversion, >99% ee, and up to 18,900 TON. Among them, two key chiral intermediates used in the synthesis of the drugs medroxalol and dilevalol were produced on a gram scale in up to 85% yield and >99% ee. Addnl., the engineered enzymes M3 and M8 displayed considerable thermostability with a half-life of more than three days at 50 °C. These results demonstrate that these engineered amine dehydrogenases are promising biocatalysts for the synthesis of chiral amines. Mol. dynamics simulations provide insights into how mutations improve the amination activity toward bulky ketones and the thermostability.

ACS Catalysis published new progress about Directed evolution. 539-88-8 belongs to class esters-buliding-blocks, name is Ethyl 4-oxopentanoate, and the molecular formula is C7H12O3, Application of Ethyl 4-oxopentanoate.

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

Li, Zhan-Ku published the artcileEthanol and formic acid as synergistic solvents for converting lignite to platform chemicals, Formula: C7H12O3, the main research area is ethanol formic acid phenol ester lignite ethanolysis.

Formic acid (FA)-catalyzed ethanolysis of Xilinguole lignite (XL) was carried out with FA to ethanol ratio of 0-1:6 mL/mL at 220-320 °C. The optimal conditions were determined to be 300 °C and FA to ethanol ratio of 1:10 mL/mL based on ethanol-soluble portion (ESP) yield and the maximum ESP yield is 48.0 wt%. Both carbon balance and Fourier transform IR spectrometric analyses confirm that FA and ethanol involved in ethanolysis of XL. Three major platform chems., i.e., arenes, phenols, and esters, were identified in ESPs by gas chromatog./mass spectrometry. The yields of arenes and phenols significantly increased from 15.67 to 58.33 mg/g and 36.02 to 168.44 mg/g with adding FA to ethanolysis of XL, resp. The alkyl groups of arenes and phenols are more abundant in ESPs from FA-catalyzed ethanolysis of XL. The results suggest that FA enhanced hydrogenolysis of aryl ethers and alkylation of ethanol during XL ethanolysis. Hydrogen generated from FA hindered dehydrogenation of ethanol, resulting in the decrease of ethanol-derived esters. Ethanol acts as in-situ hydrogen donor for hydrogenolysis and reactant for alkylation, aldol condensation, and esterification, while FA serves as acid catalyst and in-situ hydrogen donor for hydrogenolysis. Addnl., possible pathways for FA-catalyzed ethanolysis of XL were proposed.

Fuel published new progress about Aldol condensation. 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

Wu, Hongguo published the artcileHot water-promoted catalyst-free reductive cycloamination of (bio-)keto acids with HCOONH4 toward cyclic amides, Recommanded Product: Ethyl 4-oxopentanoate, the main research area is keto acid ammonium formate tandem reductive cycloamination; cyclic amide preparation.

HCOONH4 was demonstrated to be capable of acting as both hydrogen and nitrogen source in the absence of any catalyst and additive for the reductive cycloamination of bio-based levulinic acid (LA) to 5-methyl-2-pyrrolidone (MPL) with more than 90% in just 60 min at 180°. Pressurized hot water remarkably enabled the reaction efficiency and rate by promoting the hydrolysis of HCOONH4 to liberated ammonia and formic acid for the cascade reactions and this catalyst-free protocol was also applicable to the efficient synthesis of various cyclic amides from relevant keto acids. Moreover, the reaction pathways were investigated by conducting deuterium-labeling experiments and kinetic studies of selected reactions.

Journal of Supercritical Fluids published new progress about Amidation kinetics. 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

Tiong, Yong Wei published the artcileOptimisation studies on the conversion of oil palm biomass to levulinic acid and ethyl levulinate via indium trichloride-ionic liquids: A response surface methodology approach, SDS of cas: 539-88-8, the main research area is oil palm biomass LA EL indium trichloride ionic liquid.

This work is a continuation and extension of previously published study on the conversions of oil palm empty fruit bunch and mesocarp fiber biomass to levulinic acid and Et levulinate via an eco-friendly indium trichloride-1-methylimidazolium hydrogen sulfate (Tiong et al., 2017). Herein, a response surface methodol. based on a central composite design method was used to optimize the operating conditions of the conversions. The conversions consisted of a two-sequential steps, i.e., depolymerization to levulinic acid, followed by esterification to Et levulinate. The optimum depolymerization occurred at 177°C in 4.8 h with 0.15 mmol indium trichloride in ionic liquids-to-biomass ratio of 6.6:1 (weight/weight) and 22.7% (weight/weight) of water, while esterification was at 105°C in 12.2 h with ethanol to substrate ratio of 7.2:1 (volume/volume). The maximum levulinic acid yields of 17.7% and 18.4%, and the subsequent Et levulinate yields of 18.7% and 20.1% were achieved from the conversions of oil palm empty fruit bunch and mesocarp fiber biomass, resp. LA and EL efficiencies were >63% for both biomass conversions. The ionic liquids could be recycled up to three consecutive runs with a minimal loss of <25% of Et levulinate yield. This study highlighted the potential of proposed ionic liquids for biorefinery processing of renewable feedstock in a greener and sustainable approach. Industrial Crops and Products published new progress about Biomass (Oil palm). 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

Jiang, Wei published the artcileGene mining, codon optimization and analysis of binding mechanism of an aldo-keto reductase with high activity, better substrate specificity and excellent solvent tolerance, SDS of cas: 539-88-8, the main research area is Candida aldo keto reductase gene mining codon substrate specificity.

The biosynthesis of chiral alcs. has important value and high attention. Aldo-keto reductases (AKRs) mediated reduction of prochiral carbonyl compounds is an interesting way of synthesizing single enantiomers of chiral alcs. due to the high enantio-, chemo- and regioselectivity of the enzymes. However, relatively little research has been done on characterization and apply of AKRs to asym. synthesis of chiral alcs. In this study, the AKR from Candida tropicalis MYA-3404 (C. tropicalis MYA-3404), was mined and characterized. The AKR shown wider optimum temperature and pH. The AKR exhibited varying degrees of catalytic activity for different substrates, suggesting that the AKR can catalyze a variety of substrates. It is worth mentioning that the AKR could catalytic reduction of keto compounds with benzene rings, such as cetophenone and phenoxyacetone. The AKR exhibited activity on N,N-dimethyl-3-keto-3-(2-thienyl)-1-propanamine (DKTP), a key intermediate for biosynthesis of the antidepressant drug duloxetine. Besides, the AKR still has high activity whether in a reaction system containing 10%-30% V/V organic solvent. What’s more, the AKR showed the strongest stability in six common organic solvents, DMSO, acetonitrile, Et acetate, isopropanol, ethanol, and methanol. And, it retains more that 70% enzyme activity after 6 h, suggesting that the AKR has strong solvent tolerance. Furthermore, the protein sequences of the AKR and its homol. were compared, and a 3D model of the AKR docking with coenzyme NADPH were constructed. And the important catalytic and binding sites were identified to explore the binding mechanism of the enzyme and its coenzyme. These properties, predominant organic solvents resistance and extensive substrate spectrum, of the AKR making it has potential applications in the pharmaceutical field.

PLoS One published new progress about Candida tropicalis. 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

Tabanelli, Tommaso published the artcileTransfer Hydrogenation of Methyl and Ethyl Levulinate Promoted by a ZrO2 Catalyst: Comparison of Batch vs. Continuous Gas-Flow Conditions, SDS of cas: 539-88-8, the main research area is transfer hydrogenation methyl ethyl levulinate Zirconia catalyst.

The catalytic conversion of Me and Et levulinates into γ-valerolactone (GVL) by using methanol, ethanol, and 2-propanol as the H-donor/solvent, promoted by the ZrO2 catalyst, is described as carried out under both batch and gas-flow conditions. Under batch conditions, 2-propanol was found to be the best H-donor mol., with Et levulinate giving the highest yield in GVL. The reactions occurring under continuous gas-flow conditions were found to be much more efficient, also showing excellent yields in GVL when EtOH was used as the reducing agent. These experiments clearly show that the ability to release hydrogen from the alc. H-donor/solvent is the main factor driving CTH processes, while the tendency to attack the esteric group is the key step in the formation of transesterification products.

ACS Sustainable Chemistry & Engineering published new progress about Transesterification. 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

Zhao, Xuelai published the artcileSynthesis of long chain alkanes via aldol condensation over modified chitosan catalyst and subsequent hydrodeoxygenation, COA of Formula: C7H12O3, the main research area is furfural levulinic acid aldol condensation hydrodeoxygenation.

In this paper, jet fuel range alkanes were produced by aldol condensation of furfural and levulinic acid over modified chitosan catalyst and subsequent hydrodeoxygenation. NaOH modified chitosan was developed and used as a solid catalyst in the aldol condensation of furfural and levulinic acid to produce long carbon chain compounds At room temperature, the total yield of condensation products reached 94.4% over NaOH/CT-4 catalyst. The amine of chitosan plays an important role in the aldol condensation, which reacted with the aldehyde group of the furfural, producing an intermediate Schiff base and promoting the formation of condensation products. This new route avoided the occurrence of side reactions caused by NaOH. Therefore, the yield of the products was greatly increased. Moreover, kinetic anal. of the condensation reaction and the test of catalyst repeatability were also conducted with NaOH/CT-4. The condensation products were further converted to long-chain branched alkanes by hydrodeoxygenation over the 5 wt% Pd/NbOPO4 catalyst. As a potential application, these alkanes could be mixed with and used as the components of jet fuels.

Chemical Engineering Journal (Amsterdam, Netherlands) published new progress about Aldol condensation. 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

Cho, Hong Je published the artcileSelectivity Control in Tandem Catalytic Furfural Upgrading on Zeolite-Encapsulated Pt Nanoparticles through Site and Solvent Engineering, Name: Ethyl 4-oxopentanoate, the main research area is selectivity tandem catalytic furfural upgrading zeolite encapsulated platinum nanoparticle.

Selectivity control is a pressing challenge in developing selective tandem catalytic processes. In this work, we demonstrate that tailoring types of acid sites of zeolite-encapsulated Pt nanoparticles (NPs) and solvents provide a compelling strategy to manipulate product distribution in tandem catalysis. Model tandem furfural conversion with acetone and ethanol (EtOH) is investigated in cyclohexane and EtOH solvents. Pt NPs encapsulated in ZSM-5 with Bronsted acid sites (BAS) only located in intracrystalline mesopores selectively mediate the tandem Aldol condensation and subsequent hydrogenation of furfural and acetone by limiting the access of furfural to Pt sites and promoting the Aldol condensation. A combined yield of 69% toward hydrogenated Aldol adducts is achieved. In contrast, furfural hydrogenation to valeric acid (VA) and Et valerate (EV) dominates with a combined yield of 80% on Pt NPs encapsulated in ZSM-5 with Lewis acid sites (LAS) and BAS in both zeolitic micropores and intracrystalline mesopores. Concentration of EtOH in the reaction system is identified as another key parameter in selectivity control: (1) Low EtOH concentrations (EtOH to furfural ratio of <5) suppress the catalytic transfer hydrogenation pathway and favor the formation of 2-methylfuran (MF) from furfural as most hydrogenation and hydrogenolysis steps occur on Pt NPs; (2) Modest EtOH concentrations (EtOH to furfural ratio of 5-10) favor VA/EV by enabling the catalytic transfer hydrogenation pathway in zeolitic micropores and exposing intermediates to BAS prior to Pt NPs; and (3) High EtOH concentrations (EtOH to furfural ratio of >10) suppress the production of VA/EV by excessive water formation via acid catalyzed etherification of EtOH. Therefore, tailoring the nature of active sites and solvent composition are both effective strategies in manipulating the product distribution in tandem catalysis.

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

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

Furdikova, Katarina published the artcileComparison of different categories of Slovak Tokaj wines in terms of profiles of volatile organic compounds, Computed Properties of 539-88-8, the main research area is volatile organic compound furanoid Tokaj wine; Tokaj; comprehensive gas chromatography; high-resolution mass spectrometry; winemaking technologies.

The present work deals with the characterization of volatile organic compounds in wines from the Slovak Tokaj wine region. Studied wine samples were divided into 3 groups-varietal wines from registered Tokaj vine varieties, film wines Tokajske samorodne dry, and naturally sweet botrytized wines Tokaj selections. The VOCs from wines were extracted using optimized solid phase microextraction and analyzed by comprehensive two-dimensional gas chromatog. coupled to high-resolution time-of-flight mass spectrometry (HRTOF-MS). In total, 176 VOCs were identified in all 46 studied samples. It was found that the total number of VOCs in varietal wines was generally higher than in botrytized wines. All three studied categories showed characteristic VOC profiles with significant differences. Varietal wines were characterized by higher concentrations of esters and terpenoids originating from grapes. The presence of γ-octalactone, (E)-6-methylhept-2-en-4-one, and lack of benzaldehyde were typical for Tokajske samorodne dry. Tokaj selections expressed the highest concentration of di-Et malate, benzaldehyde, and furfurals. Several interesting trends were also observed The concentration of fermentation products was highest in varietal wines, while long-term matured Tokaj special wines were typified by the presence of compounds related to noble-rotten raisins (2-phenylacetaldehyde, Et 2-phenylacetate, and 2-phenylethanol), wood (cis-whisky lactone), and aging (1,1,6-trimethyl-2H-naphthalene, furfural, and 5-methylfurfural).

Molecules published new progress about Alcohols Role: BSU (Biological Study, Unclassified), BIOL (Biological Study). 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

Cao, Yang published the artcileAlterations in the gut microbiome and metabolic profile in rats acclimated to high environmental temperature, COA of Formula: C7H12O3, the main research area is animal metabolism acclimation environmental temperature gut microbiome taxonomy.

Heat acclimation (HA) is the best strategy to improve heat stress tolerance by inducing pos. physiol. adaptations. Evidence indicates that the gut microbiome plays a fundamental role in the development of HA, and modulation of gut microbiota can improve tolerance to heat exposure and decrease the risks of heat illness. In this study, for the first time, we applied 16S rRNA gene sequencing and untargeted liquid chromatog.-mass spectrometry (LC-MS) metabolomics to explore variations in the gut microbiome and faecal metabolic profiles in rats after HA. The gut microbiota of HA subjects exhibited higher diversity and richer microbes. HA altered the gut microbiota composition with significant increases in the genera Lactobacillus (a major probiotic) and Oscillospira alongside significant decreases in the genera Blautia and Allobaculum. The faecal metabolome was also significantly changed after HA, and among the 13 perturbed metabolites, (S)-AL 8810 and celastrol were increased. Moreover, the two increased genera were pos. correlated with the two upregulated metabolites and neg. correlated with the other 11 downregulated metabolites, while the correlations between the two decreased genera and the upregulated/downregulated metabolites were completely contrary. In summary, both the structure of the gut microbiome community and the faecal metabolome were improved after 28 days of HA. These findings provide novel insights regarding the improvement of the gut microbiome and its functions as a potential mechanism by which HA confers protection against heat stress.

Microbial Biotechnology published new progress about 16S rRNA Role: BSU (Biological Study, Unclassified), BIOL (Biological Study). 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