Month: February 2023

Volatile compounds and overall quality of ‘Braeburn’ apples after long-term storage: Interaction of innovative storage technologies and 1-MCP treatment was written by Schmidt, Suele Fernanda Prediger;Schultz, Erani Elizeu;Ludwig, Vagner;Berghetti, Magno Roberto Pasquetti;Thewes, Fabio Rodrigo;Anese, Rogerio de Oliveira;Both, Vanderlei;Brackmann, Auri. And the article was included in Scientia Horticulturae (Amsterdam, Netherlands) in 2020.Formula: C6H12O2 This article mentions the following:

In this study, we evaluated storage methods which sustains ‘Braeburn’ apples volatile compounds and overall quality characteristics after 9 mo of storage at 2.5°C, and their relation with 1-methylcyclopropene (1-MCP) treatment. We also proposed to evaluate if there was a relation of the Me and Et esters with flesh breakdown incidence. The storage design was composed by five atm. conditions: controlled atm. (CA) (1.2 kPa O₂), dynamic controlled atm. based on the chlorophyll fluorescence (DCA-CF), and three levels of RQ: 1.3; 1.5 and 1.7 (DCA-RQ 1.3; DCA-RQ 1.5 and DCA-RQ 1.7). In all conditions, the CO₂ was kept at 0.7 kPa and relative humidity was 94 ± 1%, whether without or with 1-MCP treatment (0.625μL L^-1). 1-MCP maintained higher flesh firmness, suppresses the ethylene production and internal ethylene concentration (IEC), due to lower ACC oxidase enzyme activity. Et acetate was not reduced by 1-MCP treatment in DCA-RQ 1.3, 1.5 and 1.7 storage conditions. Without 1-MCP, DCA-RQ 1.3 storage resulted in better flesh firmness and titratable acidity maintenance. There was no correlation of Me and Et esters with flesh breakdown. In the experiment, the researchers used many compounds, for example, Methyl2-methylbutyrate (cas: 868-57-5Formula: C6H12O2).

Methyl2-methylbutyrate (cas: 868-57-5) belongs to esters. Esters perform as high-grade solvents for a broad array of plastics, plasticizers, resins, and lacquers, and are one of the largest classes of synthetic lubricants on the commercial market. Polyesters are important plastics, with monomers linked by ester moieties. Because of their lack of hydrogen-bond-donating ability, esters do not self-associate. Consequently, esters are more volatile than carboxylic acids of similar molecular weight.Formula: C6H12O2

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

The synthesis of 1,5,7,10-tetraoxygenated 3-methylphenanthrenes was written by Finnie, Alistair A.;Hill, Robert A.. And the article was included in Journal of Chemical Research, Synopses in 1987.Formula: C10H12O3 This article mentions the following:

Treating 3,5-(MeO)₂C₆H₃CH₂CN with BuLi and then 4,2,6-Me(MeO)₂C₆H₂CO₂Me gave 4,2,6-Me(MeO)₂C₆H₂COCH(CN)C₆H₃(OMe)₂-3,5 (I). Treating I with Ac₂O and H₂SO₄ and then irradiation gave phenanthrene II (R = cyano, R¹ = Ac) (III). Treating II (R = cyano, R¹ = H) with Raney Ni in HCO₂H gave phenanthrene II (R = R¹ = H). Treating III with Br₂ in AcOH gave mono- and dibromides IV (R²-R⁴ = H, Br), with the product ratios dependent on reaction temperature and stoichiometry. In the experiment, the researchers used many compounds, for example, Methyl 2-methoxy-4-methylbenzoate (cas: 81245-24-1Formula: C10H12O3).

Methyl 2-methoxy-4-methylbenzoate (cas: 81245-24-1) belongs to esters. Esters are also usually derived from carboxylic acids. It may also be obtained by reaction of acid anhydride or acid halides with alcohols or by the reaction of salts of carboxylic acids with alkyl halides. Liquid esters of low volatility serve as softening agents for resins and plastics. Esters also include many industrially important polymers. Polymethyl methacrylate is a glass substitute sold under the names Lucite and Plexiglas; polyethylene terephthalate is used as a film (Mylar) and as textile fibres sold as Terylene, Fortrel, and Dacron.Formula: C10H12O3

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

Predicting the Genotoxicity of Thiophene Derivatives from Molecular Structure was written by Mosier, Philip D.;Jurs, Peter C.;Custer, Laura L.;Durham, Stephen K.;Pearl, Greg M.. And the article was included in Chemical Research in Toxicology in 2003.Name: Methyl 2-thienylacetate This article mentions the following:

We report several binary classification models that directly link the genetic toxicity of a series of 140 thiophene derivatives with information derived from the compounds’ mol. structure. Genetic toxicity was measured using an SOS Chromotest. IMAX (maximal SOS induction factor) values were recorded for each of the 140 compounds both in the presence and in the absence of S9 rat liver homogenate. Compounds were classified as genotoxic if IMAX ≥ 1.5 in either test or nongenotoxic if IMAX < 1.5 for both tests. The mol. structures were represented by numerical descriptors that encoded the topol., geometric, electronic, and polar surface area properties of the thiophene derivatives The classification models used were linear discriminant anal. (LDA), k-nearest neighbor classification (k-NN), and the probabilistic neural network (PNN). These were used in conjunction with either a genetic algorithm or a generalized simulated annealing to find optimal subsets of descriptors for each classifier. The quality of the resulting models was determined by the number of misclassified compounds, with preference given to models that produced fewer false neg. classifications. Model sizes ranged from seven descriptors for LDA to three descriptors for k-NN and PNN. Very good classification results were obtained with all three classifiers. Classification rates for the LDA, k-NN, and PNN models were 80, 85, and 85%, resp., for the prediction set compounds Addnl., a consensus model was generated that incorporated all three of the basic model types. This consensus model correctly predicted the genotoxicity of 95% of the prediction set compounds In the experiment, the researchers used many compounds, for example, Methyl 2-thienylacetate (cas: 19432-68-9Name: Methyl 2-thienylacetate).

Methyl 2-thienylacetate (cas: 19432-68-9) belongs to esters. Esters are also usually derived from carboxylic acids. It may also be obtained by reaction of acid anhydride or acid halides with alcohols or by the reaction of salts of carboxylic acids with alkyl halides. Cyclic esters are called lactones, regardless of whether they are derived from an organic or inorganic acid. One example of an organic lactone is γ-valerolactone.Name: Methyl 2-thienylacetate

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

Amination of Diazocarbonyl Compounds: N-H Insertion under Metal-Free Conditions was written by Luo, Xuesong;Chen, Gui;He, Lin;Huang, Xueliang. And the article was included in Journal of Organic Chemistry in 2016.Quality Control of Ethyl 2-(4-fluorophenyl)acetate This article mentions the following:

Transition-metal-free intermol. N-H insertion of α-diazocarbonyl compounds is reported. Among the series of nitrogen sources examined, dibenzenesulfonimide was found to be the choice in terms of the yields and the reaction time. Primary mechanistic experiments suggest that a pathway involving a sequence of protonation and nucleophilic substitution was preferred. In the experiment, the researchers used many compounds, for example, Ethyl 2-(4-fluorophenyl)acetate (cas: 587-88-2Quality Control of Ethyl 2-(4-fluorophenyl)acetate).

Ethyl 2-(4-fluorophenyl)acetate (cas: 587-88-2) belongs to esters. Esters perform as high-grade solvents for a broad array of plastics, plasticizers, resins, and lacquers, and are one of the largest classes of synthetic lubricants on the commercial market. Esterification is the general name for a chemical reaction in which two reactants (typically an alcohol and an acid) form an ester as the reaction product. Esters are common in organic chemistry and biological materials.Quality Control of Ethyl 2-(4-fluorophenyl)acetate

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

Simple and Practical Real-Time Analysis of Solid-Phase Reactions by Thin-Layer Chromatography was written by Wu, Chia-Hui;Chen, Chun C.;Lin, Su-Ching;Wang, Cheng-Chung. And the article was included in Synlett in 2018.HPLC of Formula: 4163-60-4 This article mentions the following:

Solid-phase synthesis is a practical approach for simplifying the time-consuming and routine purification steps in the preparation of numerous naturally occurring mols.; however, studying such reactions is difficult due to the lack of a convenient monitoring method. By using thin-layer chromatog. in conjunction with a photolabile linker on a resin, we developed a convenient and simple method for monitoring solid-phase reactions in real time by thin-layer chromatog. This method provides a user-friendly protocol for examining reaction conditions for solid-state syntheses. In the experiment, the researchers used many compounds, for example, (2S,3R,4S,5S,6R)-6-(Acetoxymethyl)tetrahydro-2H-pyran-2,3,4,5-tetrayl tetraacetate (cas: 4163-60-4HPLC of Formula: 4163-60-4).

(2S,3R,4S,5S,6R)-6-(Acetoxymethyl)tetrahydro-2H-pyran-2,3,4,5-tetrayl tetraacetate (cas: 4163-60-4) belongs to esters. Carboxylic acid esters of low molecular weight are colourless, volatile liquids with pleasant odours, slightly soluble in water. Cyclic esters are called lactones, regardless of whether they are derived from an organic or inorganic acid. One example of an organic lactone is γ-valerolactone.HPLC of Formula: 4163-60-4

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

A calibrant-free drift compensation method for gas sensor arrays was written by Maho, Pierre;Herrier, Cyril;Livache, Thierry;Comon, Pierre;Barthelme, Simon. And the article was included in Chemometrics and Intelligent Laboratory Systems in 2022.Related Products of 105-87-3 This article mentions the following:

Gas sensors lack repeatability over time. They are affected by drift, the result of changes at the sensor level and in the environment. A solution is to design software methods that compensate for the drift. Existing methods are often based on calibration samples acquired at the start of each new measurement session. However, finding a good reference compound is a difficult task and generating calibration samples is time-consuming. We propose a model-based correction method which does not require any calibration sample over time, operating ‘blindly’. In this study, we focus on the drift affecting electronic noses. To this end, we built a real data set acquired over 9 mo in real-life conditions. By using the proposed method, we show that the drift is partly compensated, thus increasing the reliability of the electronic nose. Besides, we also show that the algorithm can easily adapt if the target compounds are not all sampled during every session. In the experiment, the researchers used many compounds, for example, (E)-3,7-Dimethylocta-2,6-dien-1-yl acetate (cas: 105-87-3Related Products of 105-87-3).

(E)-3,7-Dimethylocta-2,6-dien-1-yl acetate (cas: 105-87-3) belongs to esters. Carboxylic acid esters of low molecular weight are colourless, volatile liquids with pleasant odours, slightly soluble in water. Liquid esters of low volatility serve as softening agents for resins and plastics. Esters also include many industrially important polymers. Polymethyl methacrylate is a glass substitute sold under the names Lucite and Plexiglas; polyethylene terephthalate is used as a film (Mylar) and as textile fibres sold as Terylene, Fortrel, and Dacron.Related Products of 105-87-3

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

Regioselective Syntheses of 1,2-Benzothiazine 1-Imines by Rhodium-Catalyzed Annulation Reactions of Sulfondiimines was written by Bohmann, Rebekka Anna;Schoebel, Jan-Hendrik;Unoh, Yuto;Miura, Masahiro;Bolm, Carsten. And the article was included in Advanced Synthesis & Catalysis in 2019.Computed Properties of C9H10O3S This article mentions the following:

Unprecedented 1,2-benzothiazine 1-imines I (R¹ = H, OMe, Me; R² = Me, cyclopropyl; R³ = H, Me, Ph; R⁴ = Me, thiophen-2-yl, Ph, etc.; R⁵ = H, C(O)OC₂H₅) have been prepared from sulfondiimines 4-R¹C₆H₄S(R²)(=NH)=NR³ by regioselective rhodium-catalyzed annulation reactions with diazo keto esters R⁴C(O)C(=N₂)R⁵ and α-substituted (pseudo)halo acetophenones R⁶CH₂C(O)C₆H₅ (R⁶ = Cl, tosyloxy, mesyloxy) as coupling partners. A representative product was characterized by single crystal X-ray structure anal., and the applicability of the resulting three-dimensional heterocycles I (R¹ = H, R² = Me, R³ = Ph, R⁴ = 4-bromophenyl, R⁵ = H) to Buchwald-Hartwig-type amination reactions is shown. In the experiment, the researchers used many compounds, for example, Ethyl 3-oxo-3-(thiophen-2-yl)propanoate (cas: 13669-10-8Computed Properties of C9H10O3S).

Ethyl 3-oxo-3-(thiophen-2-yl)propanoate (cas: 13669-10-8) belongs to esters. Esters perform as high-grade solvents for a broad array of plastics, plasticizers, resins, and lacquers, and are one of the largest classes of synthetic lubricants on the commercial market. Polyesters are important plastics, with monomers linked by ester moieties. Esterification is the general name for a chemical reaction in which two reactants (typically an alcohol and an acid) form an ester as the reaction product. Esters are common in organic chemistry and biological materials.Computed Properties of C9H10O3S

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

Library Synthesis Using 5,6,7,8-Tetrahydro-1,6-naphthyridines as Scaffolds was written by Zhou, Ya;Beeler, Aaron B.;Cho, Sanghyun;Wang, Yuehong;Franzblau, Scott G.;Snyder, John K.. And the article was included in Journal of Combinatorial Chemistry in 2008.Related Products of 16413-26-6 This article mentions the following:

The chem. of 5,6,7,8-tetrahydro-1,6-naphthyridine scaffolds I [R = H, R¹ = Me, R² = Ph, CH₂OPh, n-Bu; R¹ = Ph, R² = 2-Me-4-MeOC₆H₃], synthesized by intramol. cobalt-catalyzed [2 + 2 + 2] cyclizations, has been exploited for library synthesis. Urea, amide, and sulfonamide formations were used in the synthesis of a 101-membered library. Screening of the library for antituberculosis activity revealed three lead compds I [R = (R)-PhCH(Me)NHCO, 4-MeOC₆H₄NHCO, 4-NCC₆H₄SO₂, R¹ = Ph, R² = 2-Me-4-MeOC₆H₃]. In the experiment, the researchers used many compounds, for example, 3-Cyanophenylisocyanate (cas: 16413-26-6Related Products of 16413-26-6).

3-Cyanophenylisocyanate (cas: 16413-26-6) belongs to esters. Carboxylic acid esters of low molecular weight are colourless, volatile liquids with pleasant odours, slightly soluble in water. Esterification is the general name for a chemical reaction in which two reactants (typically an alcohol and an acid) form an ester as the reaction product. Esters are common in organic chemistry and biological materials.Related Products of 16413-26-6

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

Synthesis and Michael reaction of 3,4-dimethylpyrrole was written by Cheng, D. O.;Bowman, T. L.;LeGoff, E.. And the article was included in Journal of Heterocyclic Chemistry in 1976.COA of Formula: C8H11NO2 This article mentions the following:

MeCH:CHCO2Et and 4-MeC6H4SO2CH2NC gave 3-carbethoxy-4-methylpyrrole, which was reduced with NaAlH2(OCH2CH2OMe)2 to 3,4-dimethylpyrrole (I). Michael addition of Me vinyl ketone and butyn-2-one to I gave the bisadducts, 2,5-bis(3-oxobutyl)-3,4-dimethylpyrrole and 2,5-bis(3-oxobutenyl)-3,4-dimethylpyrrole, resp., while Et propiolate gave only the monoadduct, Et 3-(3,4-dimethylpyrrol-2-yl)propenoate (II). Catalytic reduction of II gave Et 3-(3,4-dimethylpyrrol-2-yl)propanoate, which with Et propiolate gave Et 3-(5-carboethoxyethyl-3,4-dimethylpyrrol-2-yl)propenoate (III). In the experiment, the researchers used many compounds, for example, Ethyl 4-methyl-1H-pyrrole-3-carboxylate (cas: 2199-49-7COA of Formula: C8H11NO2).

Ethyl 4-methyl-1H-pyrrole-3-carboxylate (cas: 2199-49-7) belongs to esters. Esters typically have a pleasant smell; those of low molecular weight are commonly used as fragrances and are found in essential oils and pheromones. Liquid esters of low volatility serve as softening agents for resins and plastics. Esters also include many industrially important polymers. Polymethyl methacrylate is a glass substitute sold under the names Lucite and Plexiglas; polyethylene terephthalate is used as a film (Mylar) and as textile fibres sold as Terylene, Fortrel, and Dacron.COA of Formula: C8H11NO2

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

Controlled radical (co)polymerization of (meth)acrylic esters via the reversible addition-fragmentation chain-transfer mechanism was written by Zaitsev, S. D.;Semchikov, Yu. D.;Vasil’eva, E. V.;Kurushina, L. V.. And the article was included in Polymer Science, Series B in 2012.Application of 27249-90-7 This article mentions the following:

The homopolymerization of acrylic and fluoroacrylic esters mediated by benzyl dithiobenzoate and dibenzyl trithiocarbonate proceeds in the controlled mode via the reversible addition-fragmentation chain-transfer mechanism, while the controlled radical polymerization of methacrylic esters is not effected under these conditions. The mol.-mass characteristics of the copolymers of acrylic and methacrylic esters may be satisfactorily controlled by benzyl dithiobenzoate-mediated copolymerization when the content of acrylic esters is no less than 50 mol %. If a reversible addition-fragmentation chain-transfer agent active with respect to only one of the monomers is used, compositionally homogeneous narrowly dispersed copolymers are formed via the azeotropic copolymerization of the monomers up to high conversions. The controlled copolymerization of N-vinylpyrrolidone and fluoroacrylates allows the synthesis of alternating narrowly dispersed amphiphilic copolymers with properties different from those of alternating copolymers with a broad mol.-mass distribution. In the experiment, the researchers used many compounds, for example, Benzyl benzodithioate (cas: 27249-90-7Application of 27249-90-7).

Benzyl benzodithioate (cas: 27249-90-7) belongs to esters. Esters are also usually derived from carboxylic acids. It may also be obtained by reaction of acid anhydride or acid halides with alcohols or by the reaction of salts of carboxylic acids with alkyl halides. Because of their lack of hydrogen-bond-donating ability, esters do not self-associate. Consequently, esters are more volatile than carboxylic acids of similar molecular weight.Application of 27249-90-7

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