Month: January 2023

Volatile and fixed composition of sulphite-free white wines obtained after fermentation in the presence of chitosan was written by Castro-Marin, Antonio;Buglia, Ana Gabriela;Riponi, Claudio;Chinnici, Fabio. And the article was included in LWT–Food Science and Technology in 2018.Recommanded Product: Ethyl 2-hydroxy-3-phenylpropanoate This article mentions the following:

Consumers are increasingly interested in healthier wines containing reduced levels or totally absent of sulphites. In the present investigation distinct fermentations of white musts either in the presence of chitosan or sulfur dioxide were carried out in order to compare the volatile and fixed composition of the wines produced, and evaluate the impact of chitosan as an alternative to sulfur dioxide. Chitosan promoted a 24 h extended lag-phase and diminished the titratable acidity of wines by about 1 g L^-1 as a consequence of the absorption of tartaric and malic acids onto the polymer surface. The volatile composition of wines was analyzed at the end of the alc. fermentation and then after 12 mo of storage in glass bottle. Hexanoic, octanoic and decanoic acids were significantly higher in chitosan added wines, which further contained an increased amount of Et and acetate esters. Results demonstrated that, when added before the alc. fermentation, chitosan may affect both the acidic and volatile composition of wines, likely due to its polycationic behavior and interaction with yeast wall constituents. This also suggests that attention to wine acidic balance should be paid before its use in other vinification steps such as must clarification or wine fining. In the experiment, the researchers used many compounds, for example, Ethyl 2-hydroxy-3-phenylpropanoate (cas: 15399-05-0Recommanded Product: Ethyl 2-hydroxy-3-phenylpropanoate).

Ethyl 2-hydroxy-3-phenylpropanoate (cas: 15399-05-0) belongs to esters. Carboxylic acid esters of low molecular weight are colourless, volatile liquids with pleasant odours, slightly soluble in water. 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.Recommanded Product: Ethyl 2-hydroxy-3-phenylpropanoate

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

Small Molecule Suppression of Carbapenem Resistance in NDM-1 Producing Klebsiella pneumoniae was written by Worthington, Roberta J.;Bunders, Cynthia A.;Reed, Catherine S.;Melander, Christian. And the article was included in ACS Medicinal Chemistry Letters in 2012.Reference of 87694-53-9 This article mentions the following:

The already considerable global public health threat of multidrug-resistant Gram-neg. bacteria has become even more of a concern following the emergence of New Delhi metallo-β-lactamase (NDM-1) producing strains of Klebsiella pneumoniae and other Gram-neg. bacteria. As an alternative approach to the traditional development of new bactericidal entities, we have identified a 2-aminoimidazole-derived small mol. that acts as an antibiotic adjuvant and is able to suppress resistance of a NDM-1 producing strain of K. pneumoniae to imipenem and meropenem, in addition to suppressing resistance of other β-lactam nonsusceptible K. pneumoniae strains. The small mol. is able to lower carbapenem min. inhibitory concentrations by up to 16-fold, while exhibiting little bactericidal activity itself. In the experiment, the researchers used many compounds, for example, (S)-tert-Butyl (1-(methoxy(methyl)amino)-1-oxo-3-phenylpropan-2-yl)carbamate (cas: 87694-53-9Reference of 87694-53-9).

(S)-tert-Butyl (1-(methoxy(methyl)amino)-1-oxo-3-phenylpropan-2-yl)carbamate (cas: 87694-53-9) 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. Esters are more polar than ethers but less polar than alcohols. They participate in hydrogen bonds as hydrogen-bond acceptors, but cannot act as hydrogen-bond donors, unlike their parent alcohols. This ability to participate in hydrogen bonding confers some water-solubility.Reference of 87694-53-9

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

Reactions with carbon suboxide was written by Hagelloch, Gunter;Feess, Erich. And the article was included in Chemische Berichte in 1951.HPLC of Formula: 1190-39-2 This article mentions the following:

C₃O₂ undergoes reactions at elevated temperatures without any noteworthy polymerization. When it is passed into dry PhMe at 100° the solution becomes increasingly yellow with a green fluorescence and, on evaporation, 20% of the C₃O₂ is recovered as polymers. In nonpolar solvents in the presence of AlCl₃, or p-MeC₆H₄SO₂H (I) at 20° no reaction takes place. Methylene bases of the Fischer-base type behave like tertiary bases and accelerate polymerization. With alcs. at 30° a slow reaction takes place; it is considerably accelerated at 65-70° with the formation of CH₂(CO₂R)₂ (II). C₃O₂ is prepared in 40-43% yield by thermal decomposition of diacetyl tartaric anhydride at 770° (cf. C.A. 27, 1325). The reactions are carried out by passing the gas through a fritted distributor into the alc., either without a solvent or in PhMe, xylene, PhNO₂, (CH₂Cl)₂ (III), or CH₂(CO₂Et)₂ at 80°. The following II are prepared: R-CH₂:CHCH₂, b₁₃ 119-20°; CH₂ClCH₂, prepared in PhMe in 13.5% yield, b₁₃ 174°; cyclohexyl, 25% at 25°, 56% at 80° or at 25° with ultraviolet irradiation, or 70% at 80° in the presence of I, b₁₃ 194°; Me₃C, in PhMe at 70°, b₁₃ 105°; p-MeC₆H₄, in PhMe with irradiation, small leaflets, m. 70°; p-O₂NC₆H₄, in PhNO₂ at 110°, leaflets, m. 174° (decomposition); picryl, in PhNO₂ at 80°, leaflets, m. 102°; o-HO₂CC₆H₄ (IV), in III with irradiation, long thin needles, m. 144° (decomposition); 3,5,2-Br₂(HO₂C)C₆H₂ (V), in xylene, fine needles, m. 176° (decomposition); 2-HOC₆H₄, in boiling C₆H₆, m. 140°, soluble in dilute NaOH, giving a red-violet color with FeCl₃. CH₂(COSBu)₂, b₁₃ 178°, and CH₂(COSCH₂Ph)₂, b₂ 195°, are prepared from the corresponding mercaptans in PhMe at 70°. C₃O₂ and glycol at 80° give a poly glycol malonate as a dark viscous oil; C₃O₂ and (CH₂CH₂OH)₂ give a very viscous dark poly butanediol malonate. The reactivity of C₃O₂ is as follows: amines > primary alcs. > phenols and nitrophenols > secondary alcs. and H₂O > thiols > tertiary alcs. IV stops the growth of Mycobacterium tuberculosis var. hominis in a solution of 1:40,000 on the Kirchner-Hermann, and 1:10,000 on the Hohn nutrient medium; V shows a lesser action. In the experiment, the researchers used many compounds, for example, malonic acid dibutyl ester (cas: 1190-39-2HPLC of Formula: 1190-39-2).

malonic acid dibutyl ester (cas: 1190-39-2) 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.HPLC of Formula: 1190-39-2

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

Disparities in chemical exposures among pregnant women and neonates by socioeconomic and demographic characteristics: A nontargeted approach was written by Goin, Dana E.;Abrahamsson, Dimitri;Wang, Miaomiao;Jiang, Ting;Park, June-Soo;Sirota, Marina;Morello-Frosch, Rachel;DeMicco, Erin;Zlatnik, Marya G.;Woodruff, Tracey J.. And the article was included in Environmental Research in 2022.Computed Properties of C20H26O4 This article mentions the following:

Exposure to environmental chems. during pregnancy adversely affects maternal and infant health, and identifying socio-demog. differences in exposures can inform contributions to health inequities. We recruited 294 demog. diverse pregnant participants in San Francisco from the Mission Bay/Moffit Long (MB/ML) hospitals, which serve a primarily higher income population, and Zuckerberg San Francisco General Hospital (ZSFGH), which serves a lower income population. We collected maternal and cord sera, which we screened for 2420 unique formulas and their isomers using high-resolution mass spectrometry using LC-QTOF/MS. We assessed differences in chem. abundances across socioeconomic and demog. groups using linear regression adjusting for false discovery rate. Our participants were racially diverse (31% Latinx, 16% Asian/Pacific Islander, 5% Black, 5% other or multi-race, and 43% white). A substantial portion experienced financial strain (28%) and food insecurity (20%) during pregnancy. We observed significant abundance differences in maternal (9 chems.) and cord sera (39 chems.) between participants who delivered at the MB/ML hospitals vs. ZSFGH. Of the 39 chem. features differentially detected in cord blood, 18 were present in pesticides, one per- or poly-fluoroalkyl substance (PFAS), 21 in plasticizers, 24 in cosmetics, and 17 in pharmaceuticals; 4 chem. features had unknown sources. A chem. feature annotated as 2,4-dichlorophenol had higher abundances among Latinx compared to white participants, those delivering at ZSFGH compared to MB/ML, those with food insecurity, and those with financial strain. Post-hoc QTOF analyses indicated the chem. feature was either 2,4-dichlorophenol or 2,5-dichlorophenol, both of which have potential endocrine-disrupting effects. Chem. exposures differed between delivery hospitals, likely due to underlying social conditions faced by populations served. Differential exposures to 2,4-dichlorophenol or 2,5-dichlorophenol may contribute to disparities in adverse outcomes. In the experiment, the researchers used many compounds, for example, Dicyclohexyl phthalate (cas: 84-61-7Computed Properties of C20H26O4).

Dicyclohexyl phthalate (cas: 84-61-7) belongs to esters. Carboxylic acid esters of low molecular weight are colourless, volatile liquids with pleasant odours, slightly soluble in water. Acyl chlorides and acid anhydrides alcoholysis is another way to produce esters. Acyl chlorides and acid anhydrides react with alcohols to produce esters. Anydrous conditions are recommended since both acyl chlorides and acid anhydrides react with water.Computed Properties of C20H26O4

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

An efficient conversion of carboxylic acids into Weinreb amides was written by Katritzky, Alan R.;Yang, Hongfang;Zhang, Suoming;Wang, Mingyi. And the article was included in ARKIVOC (Gainesville, FL, United States) [online computer file] in 2002.Quality Control of (S)-tert-Butyl (1-(methoxy(methyl)amino)-1-oxo-3-phenylpropan-2-yl)carbamate This article mentions the following:

Efficient conversions of carboxylic acids into Weinreb amides were achieved by treatment of N-acylbenzotriazoles 2a-i with N,O-dimethylhydroxylamine hydrochloride under mild conditions. No racemization was found when optically active acids were employed. In the experiment, the researchers used many compounds, for example, (S)-tert-Butyl (1-(methoxy(methyl)amino)-1-oxo-3-phenylpropan-2-yl)carbamate (cas: 87694-53-9Quality Control of (S)-tert-Butyl (1-(methoxy(methyl)amino)-1-oxo-3-phenylpropan-2-yl)carbamate).

(S)-tert-Butyl (1-(methoxy(methyl)amino)-1-oxo-3-phenylpropan-2-yl)carbamate (cas: 87694-53-9) 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. 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.Quality Control of (S)-tert-Butyl (1-(methoxy(methyl)amino)-1-oxo-3-phenylpropan-2-yl)carbamate

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

In vitro and in vivo cardiac toxicity of flavored electronic nicotine delivery systems was written by Abouassali, Obada;Chang, Mengmeng;Chidipi, Bojjibabu;Martinez, Jose Luis;Reiser, Michelle;Kanithi, Manasa;Soni, Ravi;McDonald, Thomas V.;Herweg, Bengt;Saiz, Javier;Calcul, Laurent;Noujaim, Sami F.. And the article was included in American Journal of Physiology in 2021.Application of 706-14-9 This article mentions the following:

The usage of flavored electronic nicotine delivery systems (ENDS) is popular, specifically in the teen and young adult age-groups. The possible cardiac toxicity of the flavoring aspect of ENDS is largely unknown. Vaping, a form of electronic nicotine delivery, uses “e-liquid” to generate “e-vapor,” an aerosolized mixture of nicotine and/or flavors. We report our investigation into the cardiotoxic effects of flavored e-liquids E-vapors containing flavoring aldehydes such as vanillin and cinnamaldehyde, as indicated by mass spectrometry, were more toxic in HL-1 cardiomyocytes than fruit-flavored e-vapor. Exposure of human induced pluripotent stem cell-derived cardiomyocytes to cinnamaldehyde or vanillin-flavored e-vapor affected the beating frequency and prolonged the field potential duration of these cells more than fruit-flavored e-vapor. In addition, vanillin aldehyde-flavored e-vapor reduced the human ether-a-go-go-related gene (hERG)-encoded potassium current in transfected human embryonic kidney cells. In mice, inhalation exposure to vanillin aldehyde-flavored e-vapor for 10 wk caused increased sympathetic predominance in heart rate variability measurements. In vivo inducible ventricular tachycardia was significantly longer, and in optical mapping, the magnitude of ventricular action potential duration alternans was significantly larger in the vanillin aldehyde-flavored e-vapor-exposed mice than in controls. We conclude that the widely popular flavored ENDS are not harm free, and they have a potential for cardiac harm. More studies are needed to further assess their cardiac safety profile and long-term health effects. In the experiment, the researchers used many compounds, for example, 5-Hexyldihydrofuran-2(3H)-one (cas: 706-14-9Application of 706-14-9).

5-Hexyldihydrofuran-2(3H)-one (cas: 706-14-9) belongs to esters. Carboxylic acid esters of low molecular weight are colourless, volatile liquids with pleasant odours, slightly soluble in water. Many esters have the potential for conformational isomerism, but they tend to adopt an s-cis (or Z) conformation rather than the s-trans (or E) alternative, due to a combination of hyperconjugation and dipole minimization effects. The preference for the Z conformation is influenced by the nature of the substituents and solvent, if present. Lactones with small rings are restricted to the s-trans (i.e. E) conformation due to their cyclic structure.Application of 706-14-9

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

Flavor characteristics of peanut butter pretreated by radio frequency heating, explosion puffing, microwave, and oven heating was written by Yang, Yini;Yuan, Binhong;Yu, Pei;Jia, Yimin;Zhou, Qi;Sun, Jinyuan. And the article was included in Food Chemistry in 2022.Formula: C6H10O2 This article mentions the following:

Currently, the effect of different pretreatments (i.e., radio frequency (RF), explosion puffing (EP), microwave (MW) and oven heating (OH)) on the flavor characteristics of peanut butter is unclear. Consequently, this study identified volatile aroma and non-volatile taste using HS-SPME/GC-MS combined with the use of an electronic nose, electronic tongue, and sniffing. 53 volatile compounds in four peanut butters were identified, MW-treated samples exhibited the most aroma-active compounds (43), followed by samples treated using OH (42), EP (38) and RF (21). Different pretreatment resulted in significant flavor differences in the aroma and taste. The peanut butter under MW pretreatment had a strongest nutty notes among the treatments. RF methods yielded smaller particle sizes and better texture compared to conventional OH. However, instantaneous heating using EP did not result in improvements to the aroma or taste. A combination of MW and RF may improve the flavor quality of peanut butter. In the experiment, the researchers used many compounds, for example, 5-Ethyldihydrofuran-2(3H)-one (cas: 695-06-7Formula: C6H10O2).

5-Ethyldihydrofuran-2(3H)-one (cas: 695-06-7) belongs to esters. Esters are widespread in nature and are widely used in industry. In nature, fats are in general triesters derived from glycerol and fatty acids. Esters are responsible for the aroma of many fruits. 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.Formula: C6H10O2

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

Cyclic cascade carbopalladation reactions as a route to benzene and fulvene derivatives was written by Negishi, Eiichi;Harring, Lori S.;Owczarczyk, Zbyslaw;Mohamud, Mohamud M.;Ay, Mehmet. And the article was included in Tetrahedron Letters in 1992.Reference of 17920-23-9 This article mentions the following:

Palladium-catalyzed cyclization of appropriately structured triynes, haloalkenyldiynes, or haloalkenylalkyne-alkyne mixtures can provide the corresponding benzene derivatives, while the Pd-catalyzed intermol. reaction of diynes with alkenyl halides can give fulvene derivatives Thus, MeCCCH₂OCH₂CCCH₂CR(CO₂Et)₂ (I, R = CH₂:CBrCH₂) was treated with Et₃N in MeCN in the presence of Pd(PPh₃)₄ to give 85% the cyclopentabenzofurandicarboxylate II. Similar treatment of I (R = HCCCH₂), but using 5% AcOH instead of Et₃N gave 67% II. In the experiment, the researchers used many compounds, for example, Diethyl 2-(prop-2-yn-1-yl)malonate (cas: 17920-23-9Reference of 17920-23-9).

Diethyl 2-(prop-2-yn-1-yl)malonate (cas: 17920-23-9) 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.Reference of 17920-23-9

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

Characterization of honey peach (Prunus persica (L.) Batsch) aroma variation and unraveling the potential aroma metabolism mechanism through proteomics analysis under abiotic stress was written by Li, Qianqian;Yang, Shupeng;Zhang, Rong;Liu, Shuyan;Zhang, Chaoyang;Li, Yi;Li, Jianxun. And the article was included in Food Chemistry in 2022.Category: esters-buliding-blocks This article mentions the following:

Honey peach (Prunus persica (L.) Batsch) is a climacteric fruit with short storage period. Generally, the low temperature storage (LTS) technol. is implemented to lessen aroma loss and keep the quality. However, the LTS procedure brings about cold stress issues and affects the aroma metabolism It is essential to unravel the primary aroma and the corresponding metabolism mechanism through key proteins under abiotic stress. In this study, the primary components were characterized under LTS at 1°C during 0 to 40 days. Furthermore, the proteomics anal. was performed to acquire differentially expressed proteins to clarify the underlying metabolism mechanisms of the primary aroma and potential proteins. As a result, four proteins were considered as potential key proteins that associated with fatty acid and amino acid metabolism under cold stress. Addnl., this study provides theor. cornerstones for regulating and improving the quality of honey peach. In the experiment, the researchers used many compounds, for example, 5-Hexyldihydrofuran-2(3H)-one (cas: 706-14-9Category: esters-buliding-blocks).

5-Hexyldihydrofuran-2(3H)-one (cas: 706-14-9) belongs to esters. Esters are widespread in nature and are widely used in industry. In nature, fats are in general triesters derived from glycerol and fatty acids. Esters are responsible for the aroma of many fruits. Acyl chlorides and acid anhydrides alcoholysis is another way to produce esters. Acyl chlorides and acid anhydrides react with alcohols to produce esters. Anydrous conditions are recommended since both acyl chlorides and acid anhydrides react with water.Category: esters-buliding-blocks

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

Separation and quantification of dead species in styrene RAFT polymerization by gradient polymer elution chromatography was written by Guo, Ruiwei;Shi, Zhipeng;Wang, Xingxing;Dong, Anjie;Zhang, Jianhua. And the article was included in Polymer Chemistry in 2012.Application of 27249-90-7 This article mentions the following:

In living polymerization, the inevitable dead chain impurities, due to bimol. termination and side reactions, are not only an obstacle for the synthesis of pure block copolymers but also an impairment in the application performance of the resulting polymer materials. In this paper, a simple separation and quantification method based on gradient polymer elution chromatog. (GPEC) was developed to exptl. investigate the dead species in RAFT polymerization of styrene. The RAFT-prepared polystyrene (PSt) was extended with Me acrylate in a specially-designed chain extension reaction, in which the living PSt chains were extended and transformed into block copolymer, but the remaining dead PSt chains (D-PSt) will remain constant and can be separated and quantified by GPEC. The systematic exptl. investigation of the effect of various polymerization parameters on the mass fraction of dead species (f_D-PSt) in RAFT-prepared polystyrene (PSt) was implemented. The results clearly demonstrated the initiator concentration and RAFT agent concentration can exhibit a linear and inversely proportional dependence on f_D-PSt, resp. In addition, the dead chains were found to be formed throughout the entire RAFT process. These unambiguous exptl. data confirmed the previous theor. calculation and model prediction, which may be beneficial to understand RAFT processes, optimize polymerization conditions and to minimize dead polymer contaminations. Moreover, the method based on GPEC proposed here was able to fractionate and quantify the dead and living species, which can serve as a powerful tool in the mechanistic study of the living radical polymerizations 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