Month: January 2023

Synergistic antibacterial mechanism of different essential oils and their effect on quality attributes of ready-to-eat pakchoi (Brassica campestris L. ssp. chinensis) was written by Zhang, Lihui;Zhang, Min;Ju, Ronghua;Mujumdar, Arun S.;Liu, Kun. And the article was included in International Journal of Food Microbiology in 2022.Formula: C12H20O2 This article mentions the following:

The mixture of garlic essential oil (GEO), ginger essential oil (GIEO) and litsea cubeba essential oil (LCEO) was prepared and its effect on the antibacterial activity of E. coli, S. aureus and P. aeruginosa, as well as properties of ready-to-eat pakchoi during storage were assessed. GEO, GIEO or LCEO treatment significantly enhanced the accumulation of reactive oxygen species (ROS) levels, resulting in disruption of the permeability of cell membrane, the leakage of cytoplasmic contents, and the alteration of the secondary structure of bacterial proteins. Meanwhile, GEO, GIEO or LCEO treatment repressed the key enzyme in tricarboxylic acid (TCA) and Hexose monophosphate pathway (HMP) cycle of E. coli, S. aureus and P. aeruginosa. Essential oil treatments (p < 0.05) could significantly prolong the shelf life of pakchoi, total bacterial count (TBC) values and chlorophyll content of GEO/GIEO/LCEO sample were 3.47 log cfu/g and 0.82 mg/g, resp., after storage for 7 days. E. coli, S. aureus and P. aeruginosa counts in GEO/GIEO/LCEO samples decreased by 56.76%, 70.10%, 73.95% compared to CK (no essential oil) samples. The comprehensive results from the sensory (flavor and color) and microbial anal. (especially TBC) showed that GEO/GIEO/LCEO could extend the shelf life of ready-to-eat pakchoi from 4 d to 7 d. As compared with GEO, GIEO or LCEO individually, the combination of GEO, GIEO and LCEO exhibited synergistic effect and more pronouncedly antibacterial activity to improve quality of ready-to-eat pakchoi. In the experiment, the researchers used many compounds, for example, (E)-3,7-Dimethylocta-2,6-dien-1-yl acetate (cas: 105-87-3Formula: C12H20O2).

(E)-3,7-Dimethylocta-2,6-dien-1-yl acetate (cas: 105-87-3) 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, including apples, durians, pears, bananas, pineapples, and strawberries. 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.Formula: C12H20O2

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

Total synthesis and absolute configuration of the antibiotic oligopeptide (4S)-(+)-anthelvencin A and its 4R-(-) enantiomer was written by Lee, Moses;Coulter, Diane M.;Lown, J. William. And the article was included in Journal of Organic Chemistry in 1988.Safety of Ethyl 4-nitro-1H-pyrrole-2-carboxylate This article mentions the following:

The total syntheses of (4S)-(+)-anthelvencin A (I) (the naturally occurring isomer) and its (4R)-(-) enantiomer are described. The absolute configuration of natural anthelvencin A is thereby unambiguously assigned. The two enantiomers bind to duplex calf thymus DNA. In the experiment, the researchers used many compounds, for example, Ethyl 4-nitro-1H-pyrrole-2-carboxylate (cas: 5930-92-7Safety of Ethyl 4-nitro-1H-pyrrole-2-carboxylate).

Ethyl 4-nitro-1H-pyrrole-2-carboxylate (cas: 5930-92-7) 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.Safety of Ethyl 4-nitro-1H-pyrrole-2-carboxylate

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

Effect of different cooking methods on flavor compounds of Chinese traditional condiment Wuxiang powder was written by Bi, Jicai;Li, Yang;Lin, Zeyuan;Yang, Zhen;Chen, Fusheng;Liu, Sixin;Li, Congfa. And the article was included in Journal of Food Processing and Preservation in 2022.Formula: C12H20O2 This article mentions the following:

The Wuxiang powder is a Chinese traditional condiment with a strong aroma and flavor. Moreover, it is suitable for dishes prepared using several cooking methods. Gas chromatog.-ion mobility spectrometry was used to analyze the changes in the flavor of the original Wuxiang powder, the air-fried Wuxiang powder and the stewed Wuxiang powder. A total of 49 volatile compounds were studied, including 17 aldehydes, 9 alkenes, 9 esters, 7 alcs., 2 ethers, 2 furans, 1 acid, 1 ketone and 1 phenol. The contents of aldehydes, hydrocarbons, esters and alcs. were higher than others. The principal component anal. elucidated significant differences in the aroma among different cooking methods of the Wuxiang powder. According to the relative odor activity value, the major flavor compounds that contributed to the difference in the aroma among different cooking methods were (Z, Z)-2, 4-decadienal, anethole, decanal, 3-methylbutanal, β-caryophyllene, α-pinene, linalool, eugenol, octanal, heptanal, and hexanal. In the experiment, the researchers used many compounds, for example, (E)-3,7-Dimethylocta-2,6-dien-1-yl acetate (cas: 105-87-3Formula: C12H20O2).

(E)-3,7-Dimethylocta-2,6-dien-1-yl acetate (cas: 105-87-3) 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, including apples, durians, pears, bananas, pineapples, and strawberries. 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: C12H20O2

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

Chemicals tested as space repellents against yellow-fever mosquitoes. I. Esters was written by Gouck, Harry K.;McGovern, Terence P.;Beroza, Morton. And the article was included in Journal of Economic Entomology in 1967.Reference of 15399-05-0 This article mentions the following:

A total of 242 esters were tested for effectiveness as space repellents by applying them to netting with openings large enough to allow yellow-fever mosquitoes, Aedes aegypti, to pass through, and determining the number of days the netting prevented passage of >10% of the mosquitoes to a human arm. The 5 compounds that were effective >100 days were: dipentyl, diisopentyl, and bis(1-methylbutyl) malate, hexyl p-isopropylmandelate, and bis(2-ethylhexyl) fumarate. Esters with a hydroxyl group appeared to be more effective than those without this group. In the experiment, the researchers used many compounds, for example, Ethyl 2-hydroxy-3-phenylpropanoate (cas: 15399-05-0Reference of 15399-05-0).

Ethyl 2-hydroxy-3-phenylpropanoate (cas: 15399-05-0) 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, including apples, durians, pears, bananas, pineapples, and strawberries. 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 15399-05-0

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

Gold-catalyzed Cyclization of Non-conjugated Ynone-oxime Derivatives: Incorporation of Solvent Molecule was written by Tasdemir, Volkan;Menges, Nurettin. And the article was included in Asian Journal of Organic Chemistry in 2020.COA of Formula: C9H10O3S This article mentions the following:

Au^III-promoted cyclization reaction of ynone-oxime derivatives furnished 4H-1,2-oxazine ring under mild reaction conditions. When an alc. was present in the reaction media, it was attached to the oxazine ring by the second activation of cyclic intermediate with a gold catalyst. Cholesterol, propargyl alc., phenol and some of the different alc. derivatives with alkyl chain were bonded to the oxazine ring in good yields. While amine derivatives did not attach to the ring under optimized reaction conditions, the mol. with the thiol group deactivated the gold catalyst under the same reaction conditions and did not give any cyclic products. With the obtained cyclization protocol, oxazine derivatives I [R = Et, i-Pr, Ph, etc.; Ar = Ph, 4-MeOC₆H₄, 2-thienyl] were synthesized and characterized. The proposed cyclization mechanism was drawn according to the two independent control experiments, DFT optimization and NBO charges. In the experiment, the researchers used many compounds, for example, Ethyl 3-oxo-3-(thiophen-2-yl)propanoate (cas: 13669-10-8COA of Formula: C9H10O3S).

Ethyl 3-oxo-3-(thiophen-2-yl)propanoate (cas: 13669-10-8) 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. Esters contain a carbonyl center, which gives rise to 120° C–C–O and O–C–O angles. Unlike amides, esters are structurally flexible functional groups because rotation about the C–O–C bonds has a low barrier. Their flexibility and low polarity is manifested in their physical properties; they tend to be less rigid (lower melting point) and more volatile (lower boiling point) than the corresponding amides. COA of Formula: C9H10O3S

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

Enantioselective Type II Cycloaddition of Alkynes via C-C Activation of Cyclobutanones: Rapid and Asymmetric Construction of [3.3.1] Bridged Bicycles was written by Hou, Si-Hua;Yu, Xuan;Zhang, Rui;Deng, Lin;Zhang, Mengxi;Prichina, Adriana Y.;Dong, Guangbin. And the article was included in Journal of the American Chemical Society in 2020.Product Details of 98231-07-3 This article mentions the following:

Synthesis of bridged scaffolds via Type II cyclization constitutes substantial challenges due to the intrinsic ring strain accumulated in reaction transition states. Catalytic enantioselective Type II-cyclization methods are even rarer. Here, a detailed study of developing a Rh(I)-catalyzed enantioselective intramol. Type II cyclization of alkynes via C-C activation of cyclobutanones is described. This method offers a rapid approach to access a wide range of functionalized [3.3.1]-bridged bicycles along with an exocyclic olefin and an all-carbon quaternary stereocenter. Excellent enantioselectivity has been achieved using a combination of cationic rhodium(I) and DTBM-segphos. Attributed to the redox neutral and strong acid/base-free reaction conditions, high chemoselectivity has also been observed For the oxygen-tethered substrates, the reaction can proceed at room temperature In addition, partial kinetic resolution has been achieved for substrates with existing stereocenters, forging interesting chiral tricyclic scaffolds. The methylalkyne-derived substrates gave unexpected dimeric structures in good yield with excellent enantioselectivity and complete diastereoselectivity. Furthermore, the bridged bicyclic products can be diversely functionalized through simple transformations. Finally, mechanistic studies reveal a surprising reaction pathway that involves forming a metal-stabilized anti-Bredt olefin intermediate. In the experiment, the researchers used many compounds, for example, Methyl 3,3-dimethoxycyclobutanecarboxylate (cas: 98231-07-3Product Details of 98231-07-3).

Methyl 3,3-dimethoxycyclobutanecarboxylate (cas: 98231-07-3) belongs to esters. Volatile esters with characteristic odours are used in synthetic flavours, perfumes, and cosmetics. Certain volatile esters are used as solvents for lacquers, paints, and varnishes. 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.Product Details of 98231-07-3

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

Lewis Acid Regulated Divergent Catalytic Reaction between Quinone Imine Ketals (QIKs) and 1,3-Dicarbonyl Compounds: Switchable Access to Multiple Products Including 2-Aryl-1,3-Dicarbonyl Compounds, Indoles, and Benzofurans was written by Chen, Xingyu;Lu, Sixian;Deng, Ping;Chang, Xiaoqiang;Zhao, Yifan;Ma, Yue;Zhang, Dong;Xia, Fei;Yang, Lan;Wang, Jigang;Sun, Peng. And the article was included in Advanced Synthesis & Catalysis in 2022.HPLC of Formula: 13669-10-8 This article mentions the following:

A catalytic Lewis acid regulated reaction between quinone imine ketals (QIKs) and 1,3-dicarbonyl compounds provided a divergent and tunable approach to a variety of skeletons, including a series of 2-aryl-1,3-dicarbonyl compounds, indoles and benzofurans. The use of lithium chloride and ferrous bromide gave C3- or C2-alkylation products of the QIKs. The combination of ferrous bromide and trifluoromethanesulfonic acid delivered indole derivatives Sequential hydrolysis and C3-alkylation occurred in the presence of ytterbium(III) trifluoromethanesulfonate and stoichiometric amounts of water. When the reaction was performed with trifluoromethanesulfonic acid and stoichiometric amounts of water, benzofurans are obtained. This protocol utilizes mild conditions, exhibits regio- and chemoselectivity and has broad functional group tolerance. In the experiment, the researchers used many compounds, for example, Ethyl 3-oxo-3-(thiophen-2-yl)propanoate (cas: 13669-10-8HPLC of Formula: 13669-10-8).

Ethyl 3-oxo-3-(thiophen-2-yl)propanoate (cas: 13669-10-8) belongs to esters. Volatile esters with characteristic odours are used in synthetic flavours, perfumes, and cosmetics. Certain volatile esters are used as solvents for lacquers, paints, and varnishes. 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.HPLC of Formula: 13669-10-8

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

Synthesis of new “benzyl”-thiourea derivatives and their cyclic analogs with diuretic and saluretic activity was written by Reiter, J.;Toldy, L.;Schaefer, I.;Szondy, E.;Borsy, J.;Lukovits, I.. And the article was included in European Journal of Medicinal Chemistry in 1980.Name: 4-Fluorobenzylisothiocyanate This article mentions the following:

RR¹CHNHCSNR²R³ [I; R = optionally substituted Ph; R¹ = H, Me, Et, Pr, CHMe₂, (CH₂)₆Me, cyclopropyl; R² = H, Me, Et, Bu, cyclohexyl, CH₂CH₂OH; R³ = (CH₂)₃OH, CH₂CHMeOH, CH₂CMe₂OH, CHEtCH₂OH, allyl, CH₂CMe:CH₂, CH₂CH₂OH] and their cyclic derivatives II (X = CH₂, CH₂CH₂, CH₂CHMe, CH₂CMe₂, CHEtCH₂, CH₂CH:CH) with diuretic and saluretic activity were prepared Thus, RR¹CHNH₂ were converted to RR¹CHNCS or RR¹CHNHCS₂Me, which were treated with R²R³NH to give I. Acidic cyclizaton of I using HCl gave II. The quant. structure activity relationships for I and II were determined using the Free-Wilson approach. In the experiment, the researchers used many compounds, for example, 4-Fluorobenzylisothiocyanate (cas: 2740-88-7Name: 4-Fluorobenzylisothiocyanate).

4-Fluorobenzylisothiocyanate (cas: 2740-88-7) 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. 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.Name: 4-Fluorobenzylisothiocyanate

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

Zinc-Catalyzed Synthesis of Acylsilanes Using Carboxylic Acids and a Silylborane in the Presence of Pivalic Anhydride was written by Tatsumi, Kenta;Tanabe, Sae;Tsuji, Yasushi;Fujihara, Tetsuaki. And the article was included in Organic Letters in 2019.Computed Properties of C12H22O4 This article mentions the following:

Zn-catalyzed synthesis of acylsilanes using carboxylic acids and a silylborane was achieved in the presence of pivalic anhydride. Various carboxylic acids were converted to the corresponding acylsilanes. The in situ formation of mixed anhydrides was essential in the present reaction. In the experiment, the researchers used many compounds, for example, Dimethyl decanedioate (cas: 106-79-6Computed Properties of C12H22O4).

Dimethyl decanedioate (cas: 106-79-6) 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. Esters contain a carbonyl center, which gives rise to 120° C–C–O and O–C–O angles. Unlike amides, esters are structurally flexible functional groups because rotation about the C–O–C bonds has a low barrier. Their flexibility and low polarity is manifested in their physical properties; they tend to be less rigid (lower melting point) and more volatile (lower boiling point) than the corresponding amides. Computed Properties of C12H22O4

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

Solid-state hydroxylation of polypropylene was written by Petrus, Josef;Korcuskova, Martina;Kucera, Frantisek;Jancar, Josef. And the article was included in Materials Today Communications in 2022.Computed Properties of C73H108O12 This article mentions the following:

The solid-state hydroxylation of polypropylene (PP) in water solution was investigated as a simple and attractive way for the surface hydroxylation of PP. The functionalization was initiated by potassium persulfate (K₂S₂O₈) under inert atm. The effect of various reaction parameters and surfactants on the concentration of -OH group bonded on PP backbone ([OH]_PP) and the extent of collateral reactions was discussed. The increase of [OH]_PP with the increase of initial concentration of K₂S₂O₈ ([K₂S₂O₈]₀) was proved by Fourier transform IR spectroscopy (FTIR) and XPS. β-scission and oxidative degradation of PP was detected with respect to the change of rheol. behavior, differential scanning calorimetry (DSC) and FTIR. On the other hand, inverse collateral reaction leading to the increase of molar mass were evidenced at prolonged reaction period. Surface hydroxylation was detected mainly in the amorphous phase, however at prolonged reaction period the reaction occurred even in the crystalline phase. In the experiment, the researchers used many compounds, for example, 2,2-Bis(((3-(3,5-di-tert-butyl-4-hydroxyphenyl)propanoyl)oxy)methyl)propane-1,3-diyl bis(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propanoate) (cas: 6683-19-8Computed Properties of C73H108O12).

2,2-Bis(((3-(3,5-di-tert-butyl-4-hydroxyphenyl)propanoyl)oxy)methyl)propane-1,3-diyl bis(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propanoate) (cas: 6683-19-8) 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. 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.Computed Properties of C73H108O12

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