Tag: M.W=100-150

Ristiana, Desinta Dwi published the artcileSulfonic acid-functionalized silica with controlled hydrophobicity as an effective catalyst for esterification of levulinic acid, Name: Ethyl 4-oxopentanoate, the main research area is levulinic acid esterification sulfonic silica catalyst hydrophobicity.

As one of the essential additives in biodiesel and flavoring agents, solvents, and plasticizers in industry, Et levulinate (EL) has gained attention in the last two decades, and the global production of the compound is rapidly increased over the years. So far, esterification of biomass-derived levulinic acid (LA) with ethanol (EtOH) in the presence of highly corrosive mineral acid catalysts is the most common technique for the reaction. To avoid the harsh environment during the reaction and to ease the separation of the catalyst, the research has been recently focused on developing highly active solid acid catalysts. In this research, we have systematically investigated the catalytic activity of sulfonic acid-functionalized silica (SiO2-SO3H) with different hydrophobicity for esterification of LA with EtOH. The hydrophobicity of SiO2-SO3H was tuned by incorporating three different alkylsilanes, e.g., Me (Me), octyl (Oct), and hexadecyl (HD) silanes on the surface of the material. We found that the longer the alkyl group, the lower the acidity and thus resulted in the lower the catalytic activity. On the other hand, the particle size and hydrophobicity increase with the length in the alkyl group. SiO2-SO3H modified with the Me group (SiO2-SO3H/Me) showed the highest acidity (0.76 mmol g-1) and the highest catalytic performance (70.6% conversion). Moreover, while all alkyl-modified catalysts followed pseudo-first-order, the pseudo-first-order rate constant (k1p) for the reaction over SiO2-SO3H/Me was 5.4 x 10-3 min-1. The kinetic results of this study could be useful for reactor modeling and simulation in the future.

Materials Today Communications published new progress about Contact angle. 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

Bonepally, Karunakar Reddy published the artcileRapid and Systematic Exploration of Chemical Space Relevant to Artemisinins: Anti-malarial Activities of Skeletally Diversified Tetracyclic Peroxides and 6-Aza-artemisinins, Formula: C7H12O3, the main research area is artemisinin aza preparation antimalarial; tetracyclic peroxide preparation antimalarial.

To achieve both structural changes and rapid synthesis of the tetracyclic scaffold relevant to artemisinins, we explored two kinds of de novo synthetic approaches that generate both skeletally diversified tetracyclic peroxides and 6-aza-artemisinins. The antimalarial activities of the tetracyclic peroxides with distinct skeletal arrays, however, were moderate and far inferior to artemisinins. Given the privileged scaffold of artemisinins, we next envisioned element implantation at the C6 position with a nitrogen without the trimmings of substituents and functional groups. This mol. design allowed the deep-seated structural modification of the hitherto unexplored cyclohexane moiety (C-ring) while keeping the three-dimensional structure of artemisinins. Notably, this approach induced dramatic changes of retrosynthetic transforms that allow an expeditious catalytic asym. synthesis with generation of substitutional variations at three sites (N6, C9, and C3) of the 6-aza-artemisinins. These de novo synthetic approaches led to the lead discovery with substantial intensification of the in vivo activities, which undermine the prevailing notion that the C-ring of artemisinins appears to be merely a structural unit but to be a functional area as the antimalarial pharmacophore. Furthermore, we unexpectedly found that racemic 6-aza-artemisinin (I) exerted exceedingly potent in vivo efficacies superior to the chiral one and the first-line drug, artesunate.

Journal of Organic Chemistry published new progress about Antimalarials. 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

Sun, Yujing published the artcileUsing power ultrasound to release glycosidically bound volatiles from orange juice: A new method, Safety of Ethyl 3-hydroxybutanoate, the main research area is glucose cedrol dodecanal benzaldehyde temperature ultrasound hydrolysis orange juice; Glycosidically bound volatiles; Hydrolysis; Orange juice; Release; Ultrasound.

Acid hydrolysis and enzymic hydrolysis are the main methods for releasing glycosidically bound volatiles (GBV). However, acid hydrolysis yields a strong pungent odor, and enzymic hydrolysis is time consuming. In the present study, a new method, ultrasound hydrolysis, is reported to release GBV. This method is simple, environmentally friendly, fast and effective. Large differences were observed in the released aglycons and glycosyls between ultrasound and enzymic hydrolysis of GBV. More types of aglycons were released under ultrasound than enzymic hydrolysis. Alcs. and esters were the main aglycons under enzymic hydrolysis, and terpenoids, esters and aldehydes were the main aglycons under ultrasound hydrolysis. The glycosyls released under ultrasound hydrolysis were mannose, glucose and sucrose, and those released under enzymic hydrolysis were galactose and sucrose. The present study gives a new insight into a hydrolytic method for GBV by using ultrasound hydrolysis and can provide a reference method for fruit juice aromatization.

Food Chemistry published new progress about Aromatization. 5405-41-4 belongs to class esters-buliding-blocks, name is Ethyl 3-hydroxybutanoate, and the molecular formula is C6H12O3, Safety of Ethyl 3-hydroxybutanoate.

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

Gupta, Abhishek published the artcileMosquito Olfactory Response Ensemble enables pattern discovery by curating a behavioral and electrophysiological response database, Quality Control of 5405-41-4, the main research area is biol computer science application entomol neuroscience; Biological sciences; Computer science applications; Entomology; Neuroscience.

Many exptl. studies have examined behavioral and electrophysiol. responses of mosquitoes to odors. However, the differences across studies in data collection, processing, and reporting make it difficult to perform large-scale anal. combining data from multiple studies. Here we extract and standardize data for 12 mosquito species, along with Drosophila melanogaster for comparison, from over 170 studies and curate the Mosquito Olfactory Response Ensemble (MORE), publicly available at https://neuralsystems.github.io/MORE. We demonstrate the ability of MORE in generating biol. insights by finding patterns across studies. Our anal. reveal that ORs are tuned to specific ranges of several physicochem. properties of odorants; the empty-neuron recording technique for measuring OR responses is more sensitive than the Xenopus oocyte technique; there are systematic differences in the behavioral preferences reported by different types of assays; and odorants tend to become less attractive or more aversive at higher concentrations

iScience published new progress about Aedes aegypti. 5405-41-4 belongs to class esters-buliding-blocks, name is Ethyl 3-hydroxybutanoate, and the molecular formula is C6H12O3, Quality Control of 5405-41-4.

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

Patil, Chetana R. published the artcileSingle-Pot Alcoholysis of Furfuryl Alcohol to Alkyl Levulinates Using Heterogenized p-TSA Catalyst, Synthetic Route of 539-88-8, the main research area is furfuryl alc alkyl levulinate toluene sulfonic acid catalyst alcoholysis.

Synthesis of levulinate esters which are known to be excellent sustainable fuel additives, was achieved by alcoholysis of furfuryl alc. over strong solid acid catalyst, prepared by copolymerization of p-toluenesulfonic acid with paraformaldehyde. Our catalyst possessed Broensted acidity (3 mmol/g) with an excellent stability up to 220 °C. XPS, FT-IR and Pyridine-IR along with microanal. studies confirmed the presence of terminal -SO3H functional groups responsible for Broensted acidity in the catalyst. The catalyst was found to efficiently catalyze the alcoholysis of furfuryl alc. to give alkyl levulinates under mild reaction conditions. The complete conversion of furfuryl alc. with 96% and 97% selectivities to Et and Bu levulinates could be achieved using ethanol and butanol, resp. Detailed study on effect of various reaction parameters like catalyst loading, reaction time and reaction temperature on conversion and product distribution was also carried out for the ethanolysis of furfuryl alc. to Et levulinate. The catalyst could be easily recovered and recycled for five times successfully, with no loss in its original activity.

ChemistrySelect published new progress about Agglomeration. 539-88-8 belongs to class esters-buliding-blocks, name is Ethyl 4-oxopentanoate, and the molecular formula is C7H12O3, Synthetic Route of 539-88-8.

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

Shestakova, Pavletta published the artcileHybrid catalyst with combined Lewis and Bronsted acidity based on ZrIV substituted polyoxometalate grafted on mesoporous MCM-41 silica for esterification of renewable levulinic acid, Computed Properties of 539-88-8, the main research area is Lewis acidity Zr polyoxometalate mesoporous zeolite esterification catalyst; Bronsted acidity Zr polyoxometalate mesoporous zeolite esterification.

Materials which synergistically combine Lewis and Bronsted acid properties hold potential for applications as efficient heterogeneous catalysts for preparation of biofuels and biolubricants. Herein we report new heterogeneous catalysts based on grafting the intact Lewis metal (ZrIV) substituted Keggin polyoxometalate (POM) on mesoporous silica support. A new approach for immobilization of the POM in MCM-41 silica was developed by co-condensation of Si source (tetra-Et orthosilicate, TEOS) with POM salt in the presence of a template mol. as an alternative to the commonly used acidic POM form and impregnation procedure for catalyst preparation The proposed synthesis method in combination with extraction of the template proceeded with preservation of the intact POM structure and resulted in hybrid catalysts with in situ generated Bronsted acid sites in addition to the Lewis acidity provided by the metal centers. Textural properties of the catalysts were characterized by X-ray diffraction, N2 physisorption and transmission electron microscopy (TEM). Insight into POM stability and structural transformations during synthesis, template removal and impregnation was provided by solid state 31P and 29Si NMR spectroscopy. Catalytic activity was studied in esterification reactions of levulinic acid with ethanol or octanol to value-added esters. The directly synthesized POM-functionalized hybrid catalysts exceeded the post synthesis impregnated ones, demonstrating significantly higher catalytic activity, recyclability and resistance against leaching. The proposed approach for immobilization of Lewis metal POMs in MCM-41 silica framework with in situ generation of the active Bronsted acid sites opens prospects for the development of efficient hybrid catalysts for esterification reaction, which overcomes the main limitations of common POM based catalysts such as low stability of the acid sites during the synthesis and the catalytic reaction, low surface area, agglomeration of the catalytically active phase and low stability of the Lewis metal center in presence of water.

Microporous and Mesoporous Materials published new progress about Agglomeration. 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

Sanchez-Cordoba, Carlota published the artcileOlfactometric and sensory evaluation of red wines subjected to ultrasound or microwaves during their maceration or ageing stages, Quality Control of 5405-41-4, the main research area is red wine olfactometric sensory evaluation maceration ageing stage.

In the present work, we have studied the effect that some extraction techniques, such as ultrasound or microwaves, produce on the aroma of red wines, when applied to processes of extractive nature, such as pre-fermentative maceration or ageing with oak chips (Spanish oak – Quercus pyrenaica and French oak – Quercus robur). The volatile profile has been studied by means of gas chromatog. coupled with olfactometric and mass spectrometric detection. Sensory anal. of all the wines produced has also been conducted. Although no indications were found to show that the pre-fermentative treatment with microwaves or ultrasound modified the sensory profile of the wines, the application of such energies during the ageing phase showed some pos. trends at sensory level, also confirmed by the olfactometric measurements. The application of ultrasound during the ageing of the wines resulted in a greater contribution of red fruits, aromatic intensity and wood than that obtained through microwaves. Regarding the type of oak chips, Spanish oak provided more volatile compounds than French oak and with a lower proportion of undesirable aromas. At the sensory level, Spanish oak also showed greater aromatic intensity and higher values for the wood descriptor, being preferred by the panel of judges.

LWT–Food Science and Technology published new progress about Aging, animal. 5405-41-4 belongs to class esters-buliding-blocks, name is Ethyl 3-hydroxybutanoate, and the molecular formula is C6H12O3, Quality Control of 5405-41-4.

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

Yuan, Chuan published the artcileEffect of cosolvent and addition of catalyst (HZSM-5) on hydrothermal liquefaction of macroalgae, Recommanded Product: Ethyl 4-oxopentanoate, the main research area is macroalgae HZSM catalyst hydrothermal liquefaction cosolvent effect.

Summary : The present study aimed to evaluate the effect of the direct liquefaction of macroalgae in an autoclave reactor (50 mL) possessing water and ethanol as cosolvent. The reaction conditions such as duration, temperature, algae/solvent ratio, the composition of cosolvent (ethanol-water) on product distribution, and bio-oil characterization were studied. The optimum conditions such as 300°C of temperature, 45 min of reaction time, 75% of ethanol, and algae to solvent ratio of 4/40 g/mL supported the bio-oil yield of 46.75% with a conversion rate of 95.5%. The composition and concentration of the compounds in the bio-oil produced under various doses of catalyst were described using GC-MS. The bio-oil characterization showed that the esters were most predominant in hydrothermal liquefaction with a catalyst (HZSM-5) compared with hydrothermal liquefaction in the absence of the catalyst.

International Journal of Energy Research published new progress about Algae, macro-. 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

Bakuru, Vasudeva Rao published the artcileExploring the Bronsted acidity of UiO-66 (Zr, Ce, Hf) metal-organic frameworks for efficient solketal synthesis from glycerol acetalization, Related Products of esters-buliding-blocks, the main research area is Bronsted acidity metal organic framework solketal catalyst glycerol acetalization; hafnium MOF catalyst levulinic acid acetalization; cerium MOF catalyst levulinic acid acetalization; zirconium MOF catalyst acetalization.

Zr, Ce, Hf-based isostructural UIO-66 MOFs exhibited varying degree of Bronsted acidity (UiO-66(Hf) > UiO-66(Ce) > UiO-66(Zr)) on their secondary building units owing to the differences in their oxophilicities. UIO-66(Hf) showed remarkable catalytic activity for solketal synthesis with a turnover frequency as high as 13 886 h-1, which is 90 times higher than that of UiO-66(Zr) and several orders of magnitude higher than that of H2SO4 or Zeolites.

Dalton Transactions published new progress about Acetalization. 539-88-8 belongs to class esters-buliding-blocks, name is Ethyl 4-oxopentanoate, and the molecular formula is C7H12O3, Related Products of esters-buliding-blocks.

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

Saetiao, Phonsan published the artcileUsing reactive distillation for upgrading bio-oil from co-pyrolysis of palm kernel shell and palm empty fruit bunches, Recommanded Product: Ethyl 4-oxopentanoate, the main research area is biooil copyrolysis palm kernel shell fruit reactive distillation.

Due to the poor phys. properties of raw bio-oil from pyrolysis, in this work reactive distillation was used to upgrade vaporized bio-oil from selected co-pyrolysis of palm kernel shell and palm empty fruit bunches at 75%/25% mixing ratio by using 10%Ni/HZSM-5 catalyst and ethanol at various reboiler temperatures In the pyrolysis process, the feed temperature (biooil vapor and non-condensable gas) was in the range between 35 and 230°C. The reboiler temperature not only influenced the separation of heavy oil from raw bio-oil, which would help minimize catalyst deactivation, but also possibly affected contact time of reactants with catalyst via the residence time. The vaporized bio-oil was upgraded by esterification and acetalization reactions producing levulinic acid Et ester, nonanoic acid Et ester, and 1,1-diethoxyethane. The phys. characteristics d., kinematic viscosity, water content, and pH were improved from those of the raw bio-oil.

Songklanakarin Journal of Science and Technology published new progress about Acetalization. 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