Tag: M.W=100-150

Gundekari, Sreedhar published the artcileChemo- and Regioselective Synthesis of Arylated γ-Valerolactones from Bio-based Levulinic Acid with Aromatics Using H-β Zeolite Catalyst, Related Products of esters-buliding-blocks, the main research area is regioselective valerolactone levulinic zeolite catalyst biomass renewable.

Catalytic coupling of biomass-based mols. to value-added chem. intermediates is an interesting area in biomass research. Arylated γ-valerolactones (Agvls), promising pharmaceutical intermediates that have significant biol. activity, are primarily synthesized currently through petro-route. In this paper, we report successful biomass-based synthesis of Agvls using levulinic acid (LA) and oxygen or sulfur- substituted aromatics over H-β zeolite as catalyst under solvent-free conditions. Under optimized condition, LA and anisole render 90 % conversion of former with 82 % yield of para-substituted γ-lactone. C-C bond formation followed by intra-mol. esterification is witnessed in the course of the reaction, which is highly chemo- and regioselective. Though catalyst deactivated while reuse due to deposition of organic carbon moieties as deduced from several physicochem. techniques, it could be regenerated by simple calcination.

ChemCatChem published new progress about Beta zeolites Role: CAT (Catalyst Use), USES (Uses) (sodium-exchanged, calcinated). 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

He, Yingxia published the artcileUnraveling the chemosensory characteristics of strong-aroma type Baijiu from different regions using comprehensive two-dimensional gas chromatography-time-of-flight mass spectrometry and descriptive sensory analysis, HPLC of Formula: 539-88-8, the main research area is chemosensory gas chromatog mass spectrometry; 1-Butanol (PubChem CID: 263); 2,3,5-Trimethyl-6-ethylpyrazine (PubChem CID: 28518); 2,6-Dimethylpyrazine (PubChem CID: 7938); 2-Acetylfuran (PubChem CID: 14505); Chemical and sensory profiles; Chinese strong-aroma type Baijiu; Diethyl succinate (PubChem CID: 31249); Dimethyl disulfide (PubChem CID: 12232); Furfural (PubChem CID: 7362); GC × GC-TOFMS; Methanethiol caproate (PubChem CID: 75515); Multivariate analysis; Regionality.

Comprehensive 2D gas chromatog.-time-of-flight mass spectrometry was combined with descriptive sensory anal. to elucidate the specificity of strong-aroma type Baijiu (Chinese liquor) from different regions, based on regionally distinct flavor characterized by chem. and sensory profiles. Numerous potential aroma compounds (262) were identified, among which 58 aroma compounds were significantly different between the samples from Sichuan and Jianghuai regions. Relationships between these potential aroma compounds and sensory attributes were investigated by partial least squares regression and network anal. The compounds that dominantly contributed to the important sensory attributes were identified. The high pyrazines, furanoids, and carbonyls amounts contributed to the high intensities of the cellar, toasted, and grain aroma profiles of the Sichuan region samples, while the high ester and alc. levels contributed to the fruity and floral aroma profiles of the Jianghuai region samples. This approach may have practical application in flavor characterization of other alc. beverages.

Food Chemistry published new progress about Chemoreceptors 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, HPLC of Formula: 539-88-8.

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

Morino, Yusuke published the artcileCu/N-Oxyl-catalyzed aerobic oxidative esterification to oxalic acid diesters from ethylene glycol via highly selective intermolecular alcohol oxidation, Application of Ethyl 2-hydroxyacetate, the main research area is oxalic acid diester preparation green chem; ethylene glycol primary sec alc aerobic oxidative esterification; copper tetramethylethylenediamine dimethyl azanoradamantane oxyl catalyst.

One of the ideal green esterification reactions is aerobic oxidative esterification using only a stoichiometric amount of different alcs. via intermol. selective alc. oxidation followed by hemiacetal formation by the addition of the other alc. and hemiacetal oxidation to esters. However, oxalic acid diester synthesis via oxidative esterification has not been reported to date, possibly owing to the difficulty of selectivity control of intermol. alc. oxidation and the chelating effects of ethylene glycol-derived alcs./hemiacetals on inhibiting oxidation catalysts. Herein, using a CuCl/tetramethylethylenediamine/1,5-dimethyl-9-azanoradamantane N-oxyl catalyst, authors describe a highly efficient aerobic oxidative esterification reaction of ethylene glycol to various oxalic acid diesters via selective oxidation of ethylene glycol-derived alcs./hemiacetals even in the presence of other aliphatic primary alcs. Notably, the green reaction works well using an ideal stoichiometric ratio of ethylene glycol and primary/secondary alcs. Thorough exptl. investigation and theor. calculations revealed that highly selective oxidative esterification is enabled by the preferential bidentate coordination of ethylene glycol-derived alcs./hemiacetals to the Cu(II) species, followed by efficient two-electron/one-proton transfer.

Green Chemistry published new progress about Dicarboxylic acids, diesters Role: SPN (Synthetic Preparation), PREP (Preparation). 623-50-7 belongs to class esters-buliding-blocks, name is Ethyl 2-hydroxyacetate, and the molecular formula is C4H8O3, Application of Ethyl 2-hydroxyacetate.

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

Slaghenaufi, Davide published the artcileTwo sides to one story-aroma chemical and sensory signature of Lugana and Verdicchio wines, Application In Synthesis of 5405-41-4, the main research area is Lugana Verdicchio wine sensory property aroma; Lugana; Verdicchio; chemical signature; sensory space; wine aroma.

Lugana and Verdicchio are two Italian white wines with a Protected Designation of Origin (PDO) label. These two wine types are produced in different regions using the same grape variety. The aim of this work is to investigate the existence of volatile chem. markers that could help to elucidate differences between Lugana and Verdicchio wines both at chem. and sensory levels. Thirteen com. wine samples were analyzed by Gas Chromatog.-Mass Spectrometry (GC-MS), and 76 volatile compounds were identified and quantified. Verdicchio and Lugana had been differentiated on the basis of 19 free and glycosidically bound compounds belonging to the chem. classes of terpenes, benzenoids, higher alcs., C6 alcs. and norisoprenoids. Samples were assessed by means of a sorting task sensory anal., resulting in two clusters formed. These results suggested the existence of 2 product types with specific sensory spaces that can be related, to a good extend, to Verdicchio and Lugana wines. Cluster 1 was composed of six wines, 4 of which were Lugana, while Cluster 2 was formed of 7 wines, 5 of which were Verdicchio. The first cluster was described as “”fruity””, and “”fresh/minty””, while the second as “”fermentative”” and “”spicy””. An attempt was made to relate anal. and sensory data, the results showed that damascenone and the sum of 3 of esters the Et hexanoate, Et octanoate and isoamyl acetate, was characterizing Cluster 1. These results highlighted the primary importance of geog. origin to the volatile composition and perceived aroma of Lugana and Verdicchio wines.

Molecules published new progress about Norisoprenoids Role: BSU (Biological Study, Unclassified), BIOL (Biological Study). 5405-41-4 belongs to class esters-buliding-blocks, name is Ethyl 3-hydroxybutanoate, and the molecular formula is C6H12O3, Application In Synthesis of 5405-41-4.

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

Xu, Yufei published the artcileCatalytic Transfer Hydrogenation of Biomass-derived Levulinates to γ- valerolactone Using Alcohols as H-donors, Formula: C7H12O3, the main research area is review biomass levulinate gamma valerolactone alc hydrogen donor.

Gamma-Valerolactone (GVL) is a kind of significant platform mols. in the modern industry, which can be directly produced from biomass-derivatives, such as sugar, levulinic acid (LA) and Et levulinate (EL). In general, GVL could be produced from LA using gas hydrogen as H-donor with heterogeneous or homogeneous catalysts. But this strategy always has the danger of operation and requirement of unique reactors due to explosive hydrogen as well as the acidity of reactant. Over the past decade, researchers in this field have established new processes and strategies to meet the above problems through the CTH process by using alc. as H-donor and EL as the substrate over different kinds of catalysts. In this review, we collect and discuss the literature on the production of GVL from EL, and applications of LA, EL, and GVL with particular typical mechanisms. The catalyst preparation methods in the mentioned reaction systems are also concerned.

Current Green Chemistry published new progress about Alcohols Role: BCP (Biochemical Process), BIOL (Biological Study), PROC (Process). 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

Qiu, Shuai published the artcileChemoenzymatic catalysis of tert-butyl 6-cyano-(3R,5R)-dihydroxyhexanoate by aldo-keto reductase coupled with composite Fe3O4 nanozyme scaffold, Quality Control of 539-88-8, the main research area is Exiguobacterium glucose dehydrogenase aldoketo reductase iron oxide nanoparticle.

Cofactor NADPH is widely used in enzymic redox reactions, however, its regeneration by glucose dehydrogenase (GDH) suffers from massive glucose consumption, costly wastewater treatment, and low atom efficiency. Herein, Fe3O4 nanoparticles supported on helical multi-walled carbon nanotubes (Fe3O4@HMWCNTs) was prepared and displayed comparable transfer hydrogenation activity to Exiguobacterium sibiricum GDH (EsGDH). We developed a chemoenzymic catalysis based on a combination of an aldo-keto reductase KmAKR with Fe3O4@HMWCNTs scaffold, which asym. synthesized optically pure tert-Bu 6-cyano-(3R,5R)-dihydroxyhexanoate ((3R,5R)-2, > 99.5% dep). Under the optimized conditions, 10 mM NADP+ was converted to NADPH by 5.0 mg Fe3O4@HMWCNTs, in a yield of > 80.0%. The combination of Fe3O4@HMWCNTs with KmAKRM7 completely reduced 10 mM tert-Bu 6-cyano-(5R)-hydroxy-3-oxohexanoate ((5R)-1) to (3R,5R)-2, in a conversion of > 99.0% and dep > 99.5%. Contrast to the previous developed biocatalytic approach with KmAKR and EsGDH, this efficient and compatible nanozyme-enzyme process required neither glucose/alcs. as co-substrate nor a glucose dehydrogenase/alc. dehydrogenase for NADPH regeneration.

Chemical Engineering Science published new progress about Alcohols, chiral 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, Quality Control of 539-88-8.

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

Zhang, Lei published the artcilePreharvest spraying calcium ameliorated aroma weakening and kept higher aroma-related genes expression level in postharvest ‘Nanguo’ pears after long-term refrigerated storage, Synthetic Route of 5405-41-4, the main research area is Pyrus calcium chloride aroma weakening LOX HPL ACS storage.

Refrigerated storage postponed the post-ripening of ‘Nanguo’ pears (Pyrusussuriensis Maxim.), but the aromatic esters of the pears were apt to weaken when the fruit was transferred to room temperature CaCl2 treatment, in which the pears were sprayed with 4% CaCl2 during the days before harvest, inhibited the appearance of aromatic weakening of the postharvest pears after long-term refrigerated storage in the study. CaCl2-treated pears presented higher respiration rate, ethylene production and aliphatic acids during ripening in shelf life at room temperature Higher genes expression of lipoxygenase (LOX), and hydroperoxide lyase (HPL), which were associated with LOX pathway, were found in the CaCl2-treated fruit during the ripening in shelf life. The expression levels of genes ACS, ACC, PuEIN4 and PuEIN2 were up-regulated, which were related to ethylene-related pathway. These results demonstrated that the aroma weakening of ‘Nanguo’ pears can be effectively inhibited by CaCl2 treatment and the potential inherent mechanisms are discussed.

Scientia Horticulturae (Amsterdam, Netherlands) published new progress about Aliphatic acids Role: BSU (Biological Study, Unclassified), BIOL (Biological Study). 5405-41-4 belongs to class esters-buliding-blocks, name is Ethyl 3-hydroxybutanoate, and the molecular formula is C6H12O3, Synthetic Route of 5405-41-4.

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

Zhai, Xinyu published the artcileAn efficient method using ultrasound to accelerate aging in crabapple (Malus asiatica) vinegar produced from fresh fruit and its influencing mechanism investigation, Formula: C6H12O3, the main research area is crabapple vinegar Malus fresh fruit ultrasound aging; Aroma; Cavitation; Crabapple; Mixed bacteria fermentation; Ultrasonic aging.

In this study, a kind of crabapple vinegar was developed by the method of mixed bacteria fermentation It showed that the total acids and total esters in the vinegar increased by 30.51% and 22.67%, resp. Simultaneously, ultrasound was used to treat the vinegar to shorten the time of aging. In addition, the HS-SPME-GC-MS results show that some volatile components had increased significantly, such as total esters, aldehydes and heterocycles. Combining OAV with radar chart of aroma active ingredients, the order of contribution to the characteristic aroma of crabapple vinegar was esters > alcs. > others > acids. Finally, ultrasonic cavitation and hydroxyl radicals were measured to further prove it could accelerate chem. reaction of crabapple vinegar. The results of FTIR showed that the hydrogen-bonded mols. had increased, while free mols. with irritating taste (such as ethanol and acetic acid) had decreased, which made the taste of crabapple vinegar softer. Results have showed that ultrasound is a promising technique for shortening aging time and it also provides the possibility to improve the taste of fruit vinegar.

Ultrasonics Sonochemistry published new progress about Acids Role: BUU (Biological Use, Unclassified), BIOL (Biological Study), USES (Uses). 5405-41-4 belongs to class esters-buliding-blocks, name is Ethyl 3-hydroxybutanoate, and the molecular formula is C6H12O3, Formula: C6H12O3.

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

Qian, Yu published the artcileDifferentiation and classification of Chinese Luzhou-flavor liquors with different geographical origins based on fingerprint and chemometric analysis, Recommanded Product: Ethyl 4-oxopentanoate, the main research area is Luzhou liquor flavor compound traceability fingerprint chemometric; K-nearest neighbor model (KNN); Luzhou-flavor liquor; fingerprint; flavor compounds; multivariate analysis of variance (MANOVA).

In order to differentiate and characterize Chinese Luzhou-flavor liquor according to geog. origins, the volatile flavor compounds were analyzed for forty com. Luzhou-flavor liquor samples from Sichuan, Jiangsu, and Hubei provinces. A total of 113 volatile flavor compounds were quantified; among them, 29 flavor compounds were quantified according to the internal standard method. The differences in flavor composition among different brands of Luzhou-flavor liquor were compared. A data matrix of 64 (flavor components) × 40 (samples) was studied and interpreted using chemometric anal. The research object could be naturally clustered according to geog. origin (brand) based on the hierarchical cluster anal. (HCA), principal component anal. (PCA) and multivariate anal. of variance (MANOVA) methods. A 100% of predication ability was obtained by the application of K-nearest neighbor model (KNN) for study sample classification. The results demonstrate that the abundance of volatile flavor components in liquors combined with appropriate multivariate statistical methods could be used for the division and traceability of liquors from different geog. origins. This study can provide the basis for the identification of liquor authenticity and the traceability of liquor.

Journal of Food Science published new progress about Acids Role: BUU (Biological Use, Unclassified), BIOL (Biological Study), USES (Uses). 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

Grabe, Veit published the artcileOdor-induced multi-level inhibitory maps in Drosophila, Safety of Ethyl 3-hydroxybutanoate, the main research area is Drosophila odor olfactory circuitry; Drosophila; antennal lobe; chloride imaging; inhibition; olfactory coding; sensory processing.

Optical imaging of intracellular Ca2+ influx as a correlate of neuronal excitation represents a standard technique for visualizing spatiotemporal activity of neuronal networks. However, the information-processing properties of single neurons and neuronal circuits likewise involve inhibition of neuronal membrane potential. Here, we report spatially resolved optical imaging of odor-evoked inhibitory patterns in the olfactory circuitry of Drosophila using a genetically encoded fluorescent Cl- sensor. In combination with the excitatory component reflected by intracellular Ca2+ dynamics, we present a comprehensive functional map of both odor-evoked neuronal activation and inhibition at different levels of olfactory processing. We demonstrate that odor-evoked inhibition carried by Cl- influx is present both in sensory neurons and second-order projection neurons (PNs), and is characterized by stereotypic, odor-specific patterns. Cl–mediated inhibition features distinct dynamics in different neuronal populations. Our data support a dual role of inhibitory neurons in the olfactory system: global gain control across the neuronal circuitry and glomerulus-specific inhibition to enhance neuronal information processing.

eNeuro published new progress about Brain. 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