Tag: 100-200

Characterization of key odorants in Langyatai Baijiu with Jian flavour by sensory-directed analysis was written by Du, Jingyi;Li, Yueming;Xu, Jianchun;Huang, Mingquan;Wang, Juan;Chao, Jinfu;Wu, Jihong;Sun, Huibin;Ding, Haimei;Ye, Hong. And the article was included in Food Chemistry in 2021.Reference of 695-06-7 This article mentions the following:

A study was carried out to determine systematically the key aroma-active compounds of Langyatai Baijiu with Jian flavor (LBJF) using sensory omics anal. (SOA). A total of 56 odorants were screened out using gas chromatog.-olfactometry-mass spectrometry (GC-O-MS)/Osme anal. Among them, 15 aroma-active components were first identified. After quantitation, 30 odorants had odor activity values (OAVs) > 1.0 in LBJF. Recombinant and omission experiments proved that the esters, alcs., acids, especially Et hexanoate, gamma-nonalactone, and di-Me trisulfide, were critical to the flavor of LBJF. The basic and com. liquors had obvious differences in the skeleton compositions of esters and acids. This study uncovers the characteristics of Jian flavor Baijiu (JFB) and provides a scientific basis for the quality control of JFB, which is helpful for the development of Chinese Baijiu flavor styles. In the experiment, the researchers used many compounds, for example, 5-Ethyldihydrofuran-2(3H)-one (cas: 695-06-7Reference of 695-06-7).

5-Ethyldihydrofuran-2(3H)-one (cas: 695-06-7) 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. 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 695-06-7

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

Expedient synthesis of biologically important sulfonylmethyl pyrimidines was written by Blades, Kevin;Demeritt, Julie;Fillery, Shaun;Foote, Kevin M.;Greenwood, Ryan;Gregson, Clare;Hassall, Lorraine A.;McGuire, Thomas M.;Pike, Kurt G.;Williams, Emma. And the article was included in Tetrahedron Letters in 2014.Safety of Methyl 2-(methylsulfonyl)acetate This article mentions the following:

Two novel synthetic strategies that allow rapid diversification of the sulfone moiety in sulfonylmethyl pyrimidines, a class of compounds with a wide range of biol. activity, which are of interest in a wide variety of drug discovery programs, are described. In the experiment, the researchers used many compounds, for example, Methyl 2-(methylsulfonyl)acetate (cas: 62020-09-1Safety of Methyl 2-(methylsulfonyl)acetate).

Methyl 2-(methylsulfonyl)acetate (cas: 62020-09-1) 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. 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. Safety of Methyl 2-(methylsulfonyl)acetate

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

Chemical composition, anticancer, anti-neuroinflammatory, and antioxidant activities of the essential oil of Patrinia scabiosaefolia was written by Lin, Jing;Cai, Qiao-yan;Xu, Wen;Lin, Jiu-mao;Peng, Jun. And the article was included in Chinese Journal of Integrative Medicine in 2018.Synthetic Route of C10H20O2 This article mentions the following:

Objective: To study the chem. composition, anticancer, anti-neuroinflammatory, and antioxidant activities of the essential oil of Patrinia scabiosaefolia (EO-PS). Methods: Patrinia scabiosaefolia was analyzed by gas chromatog.-mass spectrometry. Eight human carcinoma cell lines, including SGC-7901, AGS, HepG2, HT-29, HCT-8, 5-FU/HCT-8, HeLa, and MDA-MB-231, were assessed by methylthiazolyldiphenyltetrazolium bromide (MTT) assay. Anti-neuroinflammatory activity was assessed by production of interleukin (IL)-1β and IL-6 induced by lipopolysaccharide in BV-2 cells (microglia from mice). The antioxidant activity was evaluated with a 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging assay. Results: Forty-four components, representing 83.919% of the total oil, were identified in the EO-PS. The major constituents were caryophyllene oxide (12.802%), caryophyllene (6.909%), α-caryophyllene (2.927%), β-damascenone (3.435%), calarene (5.621%), and phenol (3.044%). The MTT assay showed that the EO-PS exhibited significant dose-dependent growth inhibition in the 50-200μg/mL dilution range. The EO-PS exhibited a dose-dependent scavenging activity against the DPPH radical, with an half of maximal inhibitory concentration 1.455 mg/mL. Conclusion: The EO-PS possesses a wide range of antitumor, anti-neuroinflammatory and antioxidant activities, suggesting that it may be a good candidate for further investigations of new bioactive substances. In the experiment, the researchers used many compounds, for example, Isopentyl 3-methylbutanoate (cas: 659-70-1Synthetic Route of C10H20O2).

Isopentyl 3-methylbutanoate (cas: 659-70-1) 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. 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.Synthetic Route of C10H20O2

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

Rhodium-Catalyzed Novel Carbonylative Carbotricyclization of Enediynes was written by Ojima, Iwao;Lee, Seung-Yub. And the article was included in Journal of the American Chemical Society in 2000.Category: esters-buliding-blocks This article mentions the following:

The reaction of dodec-11-ene-1,6-diynes with dimethyl(phenyl)silane in the presence of a rhodium catalyst under ambient carbon monoxide afforded fused 5-7-5-membered tricyclic structures incorporating carbon monoxide. Suitable catalysts were dicarbonyl(acetylacetonato)rhodium, dodecacarbonyl tetrarhodium and tetracarbonyldi-μ-chlorodirhodium. The compounds thus prepared were derivatives of cyclopent[e]azulen-5-one. Also prepared were derivatives of cyclohepta[2,1-c:3,4-c’]difuran and cyclohepta[2,1-c:4,5-c’]dipyrrole. In the experiment, the researchers used many compounds, for example, Diethyl 2-(prop-2-yn-1-yl)malonate (cas: 17920-23-9Category: esters-buliding-blocks).

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. 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.Category: esters-buliding-blocks

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

Antibacterial, anticandidal and antioxidant properties of Tanacetum argenteum (Lam.) Willd. subsp. flabellifolium (Boiss. & Heldr.) grierson was written by Kose, Yavuz Bulent;Lscan, Gokalp;Goger, Fatih;Demirci, Betul;Elmaci, Ceren. And the article was included in Pakistan Journal of Pharmaceutical Sciences in 2017.COA of Formula: C10H20O2 This article mentions the following:

In the present study hydrodistd. essential oil and total methanol extracts of Tanacetum argenteum subsp. flabellifolium have been evaluated for their antimicrobial and antioxidant effects. The chem. composition of the oil and the crude extract were determined by GC/FID, GC/MS and LC/DAD/ESI-MS systems resp. β-thujone (47.1%), α-pinene (19.1%) and α-thujone (10.5%) were the main compounds of the essential oil while the 5-O- eaffeoquuinic acid, 1,5-O-dieafteoquuinic acid. 4,5-O-dicaffeoquuinic acid were identified as flavonoid content of the crude extract The oil and the methanol extract were demonstrated moderate antimicrobial effects (MIC range; 0,062-2,0 mg/mL) against 21 different pathogenic micro organism. Total phenolic content was determined as 63 mg GAE in g extract and the DPPH radical scavenging effect was determined as 0.16 mg/mL (IC₅₀) and TEAC was determined as 0.21mMol. In the experiment, the researchers used many compounds, for example, Isopentyl 3-methylbutanoate (cas: 659-70-1COA of Formula: C10H20O2).

Isopentyl 3-methylbutanoate (cas: 659-70-1) 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. 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.COA of Formula: C10H20O2

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

Two-Phase Electrocoagulation of Perfumes and the Analytical Approach for Investigation of the Odor-Active Compound Changes was written by Thaveesangsakulthai, Isaya;Nhujak, Thumnoon;Kulsing, Chadin. And the article was included in ChemistrySelect in 2022.Quality Control of (E)-3,7-Dimethylocta-2,6-dien-1-yl acetate This article mentions the following:

In this study, a 2-phase electrocoagulation (EC) system has been applied to treat odor active compounds in perfume extracts The system employed an electrochem. cell using two aluminum electrodes and 2-phase electrolyte containing hexane, NaCl(aq) and the perfume compounds This approach allowed electrochem. reaction of the compounds with the subsequent changes of their profiles in the extracts The volatile compounds in the samples before and after 2-phase EC sampled at different parts of the system were tentatively identified by using solid phase micro extraction (SPME) and gas chromatog. hyphenated with mass spectrometry (GC-MS). The results revealed different types and amounts of the odor active compounds in the samples after the 2-phase EC treatment with the enhanced fruity, floral, sweet, green, minty, herbal and citrus smells. The electrochem. oxidation/reduction and esterification/hydrolysis were proposed as the possible reactions. The developed 2-phase EC technique has a potential for application in the area of cost-effective adjustment of essential oil and perfume quality. In the experiment, the researchers used many compounds, for example, (E)-3,7-Dimethylocta-2,6-dien-1-yl acetate (cas: 105-87-3Quality Control of (E)-3,7-Dimethylocta-2,6-dien-1-yl acetate).

(E)-3,7-Dimethylocta-2,6-dien-1-yl acetate (cas: 105-87-3) 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. 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 (E)-3,7-Dimethylocta-2,6-dien-1-yl acetate

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

Characterization of Warmed-Over Flavor Compounds in Surimi Gel Made from Silver Carp (Hypophthalmichthys molitrix) by Gas Chromatography-Ion Mobility Spectrometry, Aroma Extract Dilution Analysis, Aroma Recombination, and Omission Studies was written by An, Yueqi;Wen, Li;Li, Wenrong;Zhang, Xuezhen;Hu, Yang;Xiong, Shanbai. And the article was included in Journal of Agricultural and Food Chemistry in 2022.Recommanded Product: 706-14-9 This article mentions the following:

The warmed-over flavor (WOF) in surimi gels was characterized by gas chromatog.-ion mobility spectrometry, aroma extract dilution anal., aroma recombination, and omission studies. Surimi gels with different WOF levels were prepared by different gelling temperatures, and surimi gels heated at 90, 100, and 121°C were considered as the samples with light, strong, and medium WOF, resp. Based on the quantification and odor activity values, 14 aldehydes, 2 ketones, 3 alcs., 2 benzene-containing compounds, 2 N-containing compounds, 3 S-containing compounds, 3 lactones, undecanoic acid, and 4-methylphenol were recombined to build a spiked model for surimi gels with the strongest WOF, which showed the highest similarity with the original sample. Finally, a triangle test involving omission of the aroma compounds from the spiked model proved that the WOF in surimi gels was attributed to (E,E)-2,4-decadienal, heptanal, octanal, nonanal, decanal, (E)-2-nonenal, (E)-2-octenal, (E)-2-decenal, (E,E)-2,4-heptadienal, 2,3-pentanedione, 2,6-dimethylpyrazine, 2-propylpyridine, benzothiazole, 2-methoxybenzenethiol, and 2-furfurylthiol. In the experiment, the researchers used many compounds, for example, 5-Hexyldihydrofuran-2(3H)-one (cas: 706-14-9Recommanded Product: 706-14-9).

5-Hexyldihydrofuran-2(3H)-one (cas: 706-14-9) 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.Recommanded Product: 706-14-9

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

The alleviation of methyl jasmonate on loss of aroma lactones correlated with ethylene biosynthesis in peaches was written by Cai, Hongfang;Han, Shuai;Yu, Mingliang;Ma, Ruijuan;Yu, Zhifang. And the article was included in Journal of Food Science in 2020.Name: 5-Ethyldihydrofuran-2(3H)-one This article mentions the following:

The occurrence of CI results in irreversible aroma loss, especially ‘peach-like’ lactones loss during cold storage and subsequent shelf life. Me jasmonate (MeJA) treatment is effective in alleviating CI symptoms in peach fruit; however, its effect on peach aroma volatiles is still unknown. To explore the effect and mechanism of MeJA treatment on aroma loss of peaches, fruit was treated with 10μmol/L MeJA, then stored at 4°C for 3 wk, and subsequently transferred to 20°C to simulate shelf life for 3 days. Here, the ability of MeJA to regulate aroma lactones of ‘Xiahui 6’ peaches was investigated, and the expression of genes responsible for ethylene and lactones biosynthesis was considered. MeJA treatment significantly reduced internal browning index, increased ethylene production, and promoted the emission of aroma-related lactones in peaches during shelf life at room temperature In addition, MeJA also elevated the expression of PpSAMS, PpACS3, PpACS4, PpACO, and PpACX3 during or after cold storage. These results suggested that MeJA treatment could enhance chilling tolerance in peaches and induce the recovery of ethylene and aroma lactones, which is closely related to ethylene biosynthesis as revealed by upregulated genes expression of PpSAMS, PpACS3/4, and PpACO. Practical Application : This research provides theor. basis for the application of Me jasmonate in fruit preservation and the basis for mol. breeding to cultivate aroma-abundant peach fruits. In the experiment, the researchers used many compounds, for example, 5-Ethyldihydrofuran-2(3H)-one (cas: 695-06-7Name: 5-Ethyldihydrofuran-2(3H)-one).

5-Ethyldihydrofuran-2(3H)-one (cas: 695-06-7) 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. 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.Name: 5-Ethyldihydrofuran-2(3H)-one

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

Effect of Wort Boiling on Volatiles Formation and Sensory Properties of Mead was written by Starowicz, Malgorzata;Granvogl, Michael. And the article was included in Molecules in 2022.Name: 5-Hexyldihydrofuran-2(3H)-one This article mentions the following:

Mead is an alc. beverage based on bee honey, which can be prepared in different variations such as modified honey-water compositions, the addition of spices, and the use of different yeast strains. Moreover, the technol. process of mead production such as the step of wort preparation (with or without boiling of wort before fermentation) can be modified. All these factors might have a significant impact on the formation of aroma-active compounds, and therefore, sensory acceptance by consumers. High vacuum distillation, using the so-called solvent assisted flavor evaporation (SAFE) technique, or headspace-solid phase microextraction (HS-SPME) were applied for the isolation of the odorants. A sensory profile was used to monitor the changes in the aroma of the mead samples. Twenty-eight aroma-active compounds were detected during aroma extract dilution anal. (AEDA) based on gas chromatog.-olfactometry (GC-O) and were finally identified by gas chromatog.-mass spectrometry (GC-MS) using authentic reference compounds, including Me propanoate, Me 3-(methylthio)propanoate, and methional, all of them were identified for the first time in mead. Compounds with high flavor dilution (FD) factors were quantitated via stable isotope dilution anal. (SIDA) and revealed Et acetate (16.4 mg/L) to be the most abundant volatile compound, increasing to 57 mg/L after wort boiling, followed by Et hexanoate (both 1.2 mg/L). Furthermore, key aroma compounds were esters such as Et hexanoate, Et octanoate, and Et 3-methylbutanoate. The sensory panel evaluated ethanolic, honey-like, clove-like, sweet, and fruity notes as the main aroma descriptors of mead. The significant change in sensory evaluation was noted in the sweet odor of the heat-treated mead. In the experiment, the researchers used many compounds, for example, 5-Hexyldihydrofuran-2(3H)-one (cas: 706-14-9Name: 5-Hexyldihydrofuran-2(3H)-one).

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. 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.Name: 5-Hexyldihydrofuran-2(3H)-one

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

The preparation and properties of a platinized charcoal catalyst with some observations on the behavior of inhibitors was written by Baltzly, Richard. And the article was included in Journal of the American Chemical Society in 1952.Computed Properties of C11H14O3 This article mentions the following:

A Pt-C catalyst (I) notable for its inactivity in debenzylation and in dehalogenations has been developed and tested on a variety of reducible compounds It appears to reduce aliphatic CO compounds less readily than aromatic. Both I and Pd-C are inhibited toward the reduction of control substrates by bases and nucleophilic ions. To 1 g. C (Darco G-60) in the reducing bottle of a Burgess-Parr hydrogenator was added 30-50 cc. H₂O and solutions of H₂PtCl₆ and PdCl₂ containing 100 mg. Pt and 0.2 mg. Pd, resp., the bottle evacuated, filled with H, shaken 15-20 min., and the H₂O finally replaced by MeOH; when not in use, the I was stored under MeOH in a reducing bottle. The hydrogenations with I were performed in MeOH at room temperature, in general with 50 millimoles substrate in 50 cc. MeOH. A series of hydrogenations was carried out in this manner; the substrate, the hydrogenation absorption, and, where determined, the hydrogenation products, of these runs are listed in the following (H absorption rates of 5-10 millimoles/min. are marked fast, 1-5 millimoles/min. moderate, < 1 millimole/min. slow; products in parentheses were not specifically isolated but were present with reasonable certainty): cyclohexene, 1 mole very fast (cyclohexane); CH₂:CHCH₂-Cl, 1 mole moderate (C₃H₈, PrCl, HCl); PhCH₂Cl, 1 mole slow (PhMe); PhCH₂OH, about 0.2 mole very slow (Ph-Me ?, substrate possibly contaminated with PhCH₂Cl); (PhCH₂)₂O, none; PhCH₂OCONHCH₂CO₂H, none; PhNMeCH₂Ph.HCl, none; p-ClC₆H₄NH₂, none; o-ClC₆H₄NH₂, none; m-BrC₆H₄Me, none; o-BrC₆H₄OMe, very slow, -; o-BrC₆H₄CO₂Et, none; p-ClC₆H₄OC₆H₄NO₂-p, 3 moles, very fast, p-ClC₆H₄OC₆H₄NH₂-p; (PhN:)₂ + 2 moles AcOH, 1 mole very fast, 1 mole moderate (PhNH₂); (PhN:)₂, 1 mole very fast, 1 mole slow [PhNH₂, (PhNH)₂]; (PhN:)₂ in 0.019N NaOH, 1 mole very fast, (PhNH)₂; 2, 6-dimethyl-4-hydroxy-5-phenylazo-4-pyrimidinol-HCl, 2 moles fast, 5-amino-2,6-dimethyl-4-pyrimidinol (+ Ph-NH₂); PhCH:NMe, fast, PhCH₂NHMe; p-MeOC₆H₄-CH:NCHPhMe + 1.5 moles AcOH, fast, p-MeOC₆H₄CH₂-NHCHPhMe; 2, 5-(MeO)₂C₆H₃COC(:NOH)Me + 3 moles HCl, 2 moles moderate, 2, 5-(MeO)₂C₆H₃COCH(NH₂)Me.-HCl; PhCN + HCl, none; PhCH₂CN + HCl, none; PhCH₂C(:NOH)Ph, none; AcH, very slow (EtOH) AcH + morpholine, 1 mole moderate (ethylmorpholine); cyclohexanone, none; Me₂CO, none; Me₂CO + cyclohexylamine, very slow, -; p-MeOC₆H₄CHO, 1 mole moderate (anisyl alc.); p-MeOC₆H₄CHO + BuNH₂, 1 mole slow, p-MeOC₆H₄CH₂NHBu; p-HOC₆H₄Ac, 1 mole slow, polymerized product; PhCH:CHCHO, 2 moles moderate (Ph(CH₂)₃OH); AcCH₂CO₂Et, none; BzCH₂CO₂-Et, 1 mole slow, PhCH(OH)CH₂CO₂Et; 3, 4-MeO(HO)-C₆H₃CH:CAcCO₂Et, 1 mole moderate, 3, 4-MeO(HO)-C₆H₃CH₂CHAcCO₂Et; 3,4-(MeO)₂C₆H₃CH: CAcCO₂Et, 1 mole moderate, 3, 4-(MeO)₂C₆H₃CH₂CHAcCO₂Et; Ph₂CO, none; PhCH₂Bz, none; benzanisoine, none; C₆H₆ in glacial AcOH, slow not carried to completion (cyclohexane ?); C₁₀H₈ in glacial AcOH, none at 25°. Both I and Pd-C were tested with control substrates in the presence of various concentrations of inhibitors and the half-inhibitory M concentrations (given for I and Pd-C) determined for: MeO^– 0.001, 0.001; PhO^– 0.006, 0.006; I^– 0.0004, 0.0004; CN^– < 0.001, -; NH₃ 0.002, 0.002; PhCH₂NMe₂ 0.001, 0.001; and p-MeC₆H₄NH₂ 0.007, 0.005-0.006. In the experiment, the researchers used many compounds, for example, Ethyl 2-hydroxy-3-phenylpropanoate (cas: 15399-05-0Computed Properties of C11H14O3).

Ethyl 2-hydroxy-3-phenylpropanoate (cas: 15399-05-0) 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 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.Computed Properties of C11H14O3

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