Tag: 200-300

Optimization of fermentation conditions of green tea wine and changes in its main components during fermentation was written by Zhao, Xiao-yue;Xu, Huai-de;Yang, Rong-xiang. And the article was included in Shipin Kexue (Beijing, China) in 2014.Category: esters-buliding-blocks The following contents are mentioned in the article:

The fermentation process of green tea wine was optimized, and the changes in polyphenols, catechins and aroma components during fermentation were investiated. Orthogonal array experiments were used to optimize the fermentation process. The changes in catechins and aroma components were determined by high performance liquid chromatog. (HPLC) and gas chromatog.-mass spectrometry (GC-MS). The optimal fermentation parameters were determined as follows: 4 g/L green tea infusion with 20% glucose and 50 g/L honey added, 5 g/L wine yeast inoculum size, and fermentation at 28°C for 10 days. The contents of six catechins were increased during fermentation Specifically, the contents of (-)-epigallocatechin (EGC), (-)-gallocatechin gallate (GCG), epicatechin gallate (ECG), and epicatechin (EC) were slightly increased; however, the contents of catechin (C) and epigallocatechin-3-gallate catechin (EGCGC) were increased by 10.88 and 17.33-folds, resp. These results indicate that the increase of catechins plays an important role in the health-promoting function of green tea wine. There were 87, 88 and 94 aroma components in the wine at the initial and the last stages of fermentation and the aged wine, which accounted for 92.93%, 98.26% and 91.87% of the total volatile components, resp. The significant differences in the types and amounts of aroma components indicate the transition from the tea flavor to the wine aroma components. Green tea can be fermented into wine; the health-promoting components (catechins) of green tea are increased to different extents and the green tea wine is mellow. This study involved multiple reactions and reactants, such as 2-Ethylhexyl benzoate (cas: 5444-75-7Category: esters-buliding-blocks).

2-Ethylhexyl benzoate (cas: 5444-75-7) 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. 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.Category: esters-buliding-blocks

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

An alternative route to cyclic terpenes by reductive cyclization in iridoid biosynthesis was written by Geu-Flores, Fernando;Sherden, Nathaniel H.;Courdavault, Vincent;Burlat, Vincent;Glenn, Weslee S.;Wu, Cen;Nims, Ezekiel;Cui, Yuehua;O’Connor, Sarah E.. And the article was included in Nature (London, United Kingdom) in 2012.Reference of 37905-02-5 The following contents are mentioned in the article:

The iridoids comprise a large family of distinctive bicyclic monoterpenes that possess a wide range of pharmacol. activities, including anticancer, anti-inflammatory, antifungal and antibacterial activities. Addnl., certain iridoids are used as sex pheromones in agriculturally important species of aphids, a fact that has underpinned innovative and integrated pest management strategies. To harness the biotechnol. potential of this natural product class, the enzymes involved in the biosynthetic pathway must be elucidated. Here we report the discovery of iridoid synthase, a plant-derived enzyme that generates the iridoid ring scaffold, as evidenced by biochem. assays, gene silencing, coexpression anal. and localization studies. In contrast to all known monoterpene cyclases, which use geranyl diphosphate as substrate and invoke a cationic intermediate, iridoid synthase uses the linear monoterpene 10-oxogeranial as substrate and probably couples an initial NAD(P)H-dependent reduction step with a subsequent cyclization step via a Diels-Alder cycloaddition or a Michael addition Our results illustrate how a short-chain reductase was recruited as cyclase for the production of iridoids in medicinal plants. Furthermore, we highlight the prospects of using unrelated reductases to generate artificial cyclic scaffolds. Beyond the recognition of an alternative biochem. mechanism for the biosynthesis of cyclic terpenes, we anticipate that our work will enable the large-scale heterologous production of iridoids in plants and microorganisms for agricultural and pharmaceutical applications. This study involved multiple reactions and reactants, such as (2E,6E)-3,7-Dimethyl-8-oxoocta-2,6-dien-1-yl acetate (cas: 37905-02-5Reference of 37905-02-5).

(2E,6E)-3,7-Dimethyl-8-oxoocta-2,6-dien-1-yl acetate (cas: 37905-02-5) 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. 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.Reference of 37905-02-5

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

Direct Immersion-Solid-Phase Microextraction Coupled to Gas Chromatography-Mass Spectrometry and Response Surface Methodology for Nontarget Screening of (Semi-) Volatile Migrants from Food Contact Materials was written by Su, Qi-Zhi;Vera, Paula;Nerin, Cristina. And the article was included in Analytical Chemistry (Washington, DC, United States) in 2020.Category: esters-buliding-blocks The following contents are mentioned in the article:

Toward a more rigorous inspection of food contact materials, the importance of sample preparation for nontarget screening should be addressed. Direct immersion-solid-phase microextraction coupled to gas chromatog. mass spectrometry (DI-SPME-GC-MS) was optimized for nontarget screening of migrants in 3% acetic acid, 10% ethanol, and 95% ethanol food simulants by response surface methodol. (RSM) in the present study. Optimum conditions were DVB/CAR/PDMS fiber, no pH adjustment for 10% and 95% ethanol simulant but pH adjustment to 7 for 3% acetic acid simulant, no salt addition, 5 min preincubation, 55 min extraction at 70°C, and 8 min desorption at 250°C. In addition, 9.5 times dilution of 95% ethanol samples prior to extraction was required. pH modification of 3% acetic acid samples was found to be critical for the extraction of amines. The proposed methodol. was then evaluated by determining the limit of detection (LOD) as well as repeatability of 35 food contact materials-related substances. Except for those amines and diols which have a relatively high LOD, the LODs of the rest of the substances were 0.1-14.1μg/kg with a precision of 1.9-23.0% in 10% ethanol and were 0.1-20.2μg/kg with a precision of 2.5-19.6% in 3% acetic acid simulant. The LOD and precision in 95% ethanol simulant were 0.7-163.7μg/kg and 1.4-26.8%, resp. The proposed method can be applied for an overall screening of migrants from these three simulants at even trace levels, though attention should be paid to some specific analytes, e.g., diols and amines, which could have a high LOD and toxicity. This study involved multiple reactions and reactants, such as Diphenyl carbonate (cas: 102-09-0Category: esters-buliding-blocks).

Diphenyl carbonate (cas: 102-09-0) 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. 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.Category: esters-buliding-blocks

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

A New Kind of Nonconventional Luminogen Based on Aliphatic Polyhydroxyurethane and Its Potential Application in Ink-Free Anticounterfeiting Printing was written by Feng, Zihao;Zhao, Wei;Liang, Zhenhua;Lv, Yanfeng;Xiang, Fukang;Sun, Deqiang;Xiong, Chuanyin;Duan, Chao;Dai, Lei;Ni, Yonghao. And the article was included in ACS Applied Materials & Interfaces in 2020.Category: esters-buliding-blocks The following contents are mentioned in the article:

Organic luminogens have extensive applications due to their unique photophys. properties. In recent years, nonconjugated organic luminogens, in contrast to traditional conjugated luminogens, have gained much attention because of their facile preparation, environmental friendliness, and biocompatibility. In this study, a new kind of nonconventional luminogen based on dynamic covalent cross-linked polyhydroxyurethane is reported for the first time. The new luminogen not only exhibits intrinsic strong fluorescent emission in the solid state but also possesses high mech. properties along with good shape memory and self-healing properties. In addition, the new luminogens are synthesized from aliphatic polyfunctional cyclic carbonate and amines via a much more straightforward method, avoiding the use of toxic isocyanates. Investigations indicated that the intrinsic luminescence of the resultant luminogens was induced by the crosslinking of polymer chains and could be well tuned by controlling the degree of crosslinking. By taking advantage of the unique characteristics of the resultant polymer luminogens, we further developed a facile method, named “light-mediated ink-free screen printing”, for anticounterfeiting paper fabrication. Different from traditional ink-based printing technol., the new method used UV-light instead of expensive security ink to encode anticounterfeiting information on natural cellulose paper. The anticounterfeiting information is stable under various wet conditions, showing promising applications in the fast-growing counterfeiting of pharmaceuticals, packaging, and the food industry. This study involved multiple reactions and reactants, such as Diphenyl carbonate (cas: 102-09-0Category: esters-buliding-blocks).

Diphenyl carbonate (cas: 102-09-0) 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. 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.Category: esters-buliding-blocks

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

In situ measurements of gas/particle-phase transitions for atmospheric semivolatile organic compounds was written by Williams, Brent J.;Goldstein, Allen H.;Kreisberg, Nathan M.;Hering, Susanne V.. And the article was included in Proceedings of the National Academy of Sciences of the United States of America in 2010.Related Products of 5444-75-7 The following contents are mentioned in the article:

An understanding of gas/particle partitioning of semi-volatile compounds is critical to determine atm. aerosol formation processes and growth rates, which in turn affect global climate and human health. The Study of Organic Aerosol at Riverside 2005 campaign was performed to better understand the factors responsible for aerosol formation and growth in Riverside, California, a region with high secondary organic aerosol concentrations formed by phase transfer of low-volatility reaction products from the precursor gas oxidation The ability of a thermal desorption aerosol gas chromatograph (TAG) to measure gas-to-particle phase transitioning for several organic compound classes (polar and non-polar) in the ambient Riverside atm. was assessed using in-situ observations of several hundred semi-volatile organic compounds TAG measurements were compared to modeled partitioning of select semi-volatile organic compounds Although TAG was not designed to quantify semi-volatile organic vapor phases, TAG measurements distinguished when specific compounds are dominantly in the vapor phase, are dominantly in the particle phase, or have both phases present. Since TAG data are speciated and time-resolved, this distinction is sufficient to determine the transition from vapor to particle phase as a function of C number and compound class. Laboratory studies typically measure semi-volatile organic compound phase partitioning using pure compounds or simple mixtures; hourly TAG phase partitioning measurements can be made in a complex mixture of thousands of polar/non-polar and organic/inorganic compounds in the atm. This study involved multiple reactions and reactants, such as 2-Ethylhexyl benzoate (cas: 5444-75-7Related Products of 5444-75-7).

2-Ethylhexyl benzoate (cas: 5444-75-7) 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, including apples, durians, pears, bananas, pineapples, and strawberries. 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.Related Products of 5444-75-7

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

Effect of MeJA treatment and scale insect attack on the volatile of jujube trees was written by Gong, Sha;Zhang, Yan-feng;Xue, Jiao-liang;Du, Xian-dang;Xie, Ying-ping. And the article was included in Shengwuxue Zazhi in 2012.Reference of 5444-75-7 The following contents are mentioned in the article:

The jujube tree, Ziziphus jujube Mill, is one of the most important economic fruits in north China. Japanese wax scale, Ceroplastes japonicus Green, is a destructive pest in the jujube orchard. This paper studied the changes of the volatile of the jujube trees that were induced with Methyl-Jasmonic (MeJA), an exogenous signaling material, or were attacked by adults of the scale insect, C. japonicus. The headspace volatile trapping instrument was used to collect volatiles from jujube trees. The chem. components of the collected volatiles were analyzed using chromatog./mass spectroscopy (GC/MS). The results showed that the volatile substances were changed both in the components and in emission quantity when the jujube trees treated with MeJA or damaged by the scale insect. Twenty-two components were examined from the volatile samples from the MeJA-treated jujube tree, and their emission quantity was 37347 ng/h. Meanwhile, 24 components were determined in the volatiles from the scale insect-damaged jujube trees and their emission quantity reached 54292 ng/h. In comparison, 14 compounds were detected only in the volatiles of the health trees (as control) and the total emission quantity was 18611 ng/h. The difference reached the significant level either between the MeJA-treated section and the control section or between the scale insect-damaged section and the control section. In which, the increases of terpenoid, alc. and ester compounds are significant in plants induced chem. defense. These compounds were considered to associate with the natural enemy recruitment in the biol. pest control. This study involved multiple reactions and reactants, such as 2-Ethylhexyl benzoate (cas: 5444-75-7Reference of 5444-75-7).

2-Ethylhexyl benzoate (cas: 5444-75-7) 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. 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.Reference of 5444-75-7

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

Solubility and dissolution rate enhancement of ibuprofen by cyclodextrin based carbonate nanosponges was written by Shoaib, Qurat-ul-ain;Latif, Sumera;Ijaz, Qazi Amir;Afzal, Hafsa;Siddique, Muhammad Irfan;Hussain, Amjad;Arshad, Muhammad Sohail;Bukhari, Nadeem Irfan;Abbas, Nasir. And the article was included in Pakistan Journal of Pharmaceutical Sciences in 2021.Recommanded Product: Diphenyl carbonate The following contents are mentioned in the article:

In the present study nanotechnol. approach, i.e., a cyclodextrin (CD) based carbonate nanosponge was used to improve the solubility and dissolution of ibuprofen. Solvent and ultrasound assisted methods were used to prepare nanosponges using two CDs (β-CD and 2-hydroxypropyl-β-CD (2HP-β-CD)) and a cross-linker (CL) di-Ph carbonate (DPC) in varying molar ratios. Nanosponges were investigated for their solubilizing efficiency and phase solubility studies. Structural anal. by Fourier transform IR (FTIR) and powder X-ray diffraction (PXRD), thermo-anal. characterization by differential scanning calorimetry (DCS), morphol. by SEM (SEM). In-vitro drug release followed by in-vivo analgesic and anti-inflammatory studies were performed. 2HP-β-CD based nanosponges (molar ratio 0.01:0.04) prepared by ultrasound assisted method showed the highest solubilizing efficiency (i.e., 4.28 folds). Stability constant values showed that all complexes were stable. Inclusion complexes of drug was confirmed by PXRD and DSC. SEM images showed porous structures confirming the formation of cross-linked network. Particle size was in the range of 296.8 ± 64 to 611.7 ± 32nm. In-vitro release studies showed enhanced dissolution profile from nanosponge formulation (~94% from I11) as compared to the pure drug (~45% Ibuprofen) in 120min. Significant (p<0.05) extent of pain inhibition and anti-inflammatory activity was observed for nanosponge formulation when compared with the pure drug. CD based carbonate nanosponges with better solubility, enhanced release profile, improved analgesic and anti-inflammatory activity were successfully formulated for ibuprofen. This study involved multiple reactions and reactants, such as Diphenyl carbonate (cas: 102-09-0Recommanded Product: Diphenyl carbonate).

Diphenyl carbonate (cas: 102-09-0) 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.Recommanded Product: Diphenyl carbonate

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

Female sex pheromone release and the timing of male flight in the red bollworm Diparopsis castanea Hmps. (Lepidoptera, Noctuidae), measured by pheromone traps was written by Marks, R. J.. And the article was included in Bulletin of Entomological Research in 1976.COA of Formula: C14H24O2 The following contents are mentioned in the article:

The female sex pheromone gland of D. castanea consists of modified intersegmental tissue between the 8th and 9th abdominal segments. Glands contain an average of 12.75 × 10-3 μg of pheromone consisting of 80.4% trans-9,11-dodecadien-1-yl acetate (range 72.7-86.7%) and 19.6% 11-dodecen-1-yl acetate (range 13.3-27.3%). Although no significant correlation exists between female body weight and pheromone content of the gland, the duration of sex pheromone release over the lifespan of a female is positively correlated with its weight on emergence. Six behavioral steps may be recognized in the precopulatory behavior of females, but the frequency and duration of sex pheromone release is strongly influenced by both temperature and light intensity. At 25° females typically call on ≥2 occasions for 41-50% of the night, calling commencing earlier at cool (13.4.degree.) temperatures than at moderate (19.4.degree.) or warm (25.0.degree.) temperatures Calling by mated females increases considerably from 4 to 5 nights after mating but is typically of shorter duration than for virgins. The dispersal flight of Diparopsis males in cotton crops commences almost immediately after sunset and before the end of dusk, with peak male catches in sex pheromone traps occurring earlier in the cooler months of May and June (20:00-2:00 hr) than in November (02:00-04:00 hr). The Diparopsis synthetic sex pheromone, dicastalure, traps a greater proportion of males and females both earlier and later in the night than virgin females and this timing advantage may be important in a pheromone control program based on disruption of communication between the sexes. This study involved multiple reactions and reactants, such as (E)-Dodeca-9,11-dien-1-yl acetate (cas: 50767-78-7COA of Formula: C14H24O2).

(E)-Dodeca-9,11-dien-1-yl acetate (cas: 50767-78-7) 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. 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.COA of Formula: C14H24O2

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

Alkaline Soil Degradation and Crop Safety of 5-Substituted Chlorsulfuron Derivatives was written by Wu, Lei;Hua, Xue-Wen;Li, Yong-Hong;Wang, Zhong-Wen;Zhou, Sha;Li, Zheng-Ming. And the article was included in Molecules in 2022.Formula: C13H10O3 The following contents are mentioned in the article:

Sulfonylurea herbicides can lead to serious weed resistance due to their long degradation times and large-scale applications. This is especially true for chlorsulfuron, a widely used acetolactate synthase inhibitor used around the world. Its persistence in soil often affects the growth of crop seedlings in the following crop rotation, and leads to serious environmental pollution all over the world. Our research goal is to obtain chlorsulfuron-derived herbicides with high herbicidal activities, fast degradation times, as well as good crop safety. On account of the slow natural degradation of chlorsulfuron in alk. soil, based on the previously reported results in acidic soil, the degradation behaviors of 5-substituted chlorsulfuron analogs (L101-L107) were investigated in a soil with pH 8.39. The exptl. data indicated that 5-substituted chlorsulfuron compounds could accelerate degradation rates in alk. soil, and thus, highlighted the potential for rational controllable degradation in soil. The degradation rates of these chlorsulfuron derivatives were accelerated by 1.84-77.22-fold, compared to chlorsulfuron, and exhibited excellent crop safety in wheat and corn (through pre-emergence treatment). In combination with bioassay activities, acidic and alk. soil degradation, and crop safety, it was concluded that compounds L104 and L107, with Et or Me groups, are potential green sulfonylurea herbicides for pre-emergence treatment on wheat and corn. This paper provides a reference for the further design of new sulfonylurea herbicides with high herbicidal activity, fast, controllable degradation rates, and high crop safety. This study involved multiple reactions and reactants, such as Diphenyl carbonate (cas: 102-09-0Formula: C13H10O3).

Diphenyl carbonate (cas: 102-09-0) 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.Formula: C13H10O3

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

Evaluation of antioxidant enzyme content, phenolic content, and antibacterial activity of Commiphora gileadensis grown in Saudi Arabia was written by Almulaiky, Yaaser Q.;Al-Farga, Ammar. And the article was included in Main Group Chemistry in 2020.Reference of 5444-75-7 The following contents are mentioned in the article:

Commiphora gileadensis is commonly used in Saudi Arabia for oral hygiene. A lack of data about its biol. activity encouraged us to evaluate the antioxidant and antibacterial activities of its leaf and stem extracts Ethanol, methanol, acetone and deionized water were tested as extraction solvents. 80% methanol gave the highest extracted concentrations of phenolic and flavonoid substances. The leaf and stem extracts were resp. evaluated for their radical scavenging activity with DPPH (EC₅₀ = 3.39, and 1.06), ABTS (EC₅₀ = 0.690, and 0.55), and peroxide scavenging activity (EC₅₀ = 2.43, and 1.28). GC-MS identified a wide range of compounds that may be responsible for these activities of the results observed The highest levels of chlorophyll, carotenoids, and lycopene were found in the leaf extract while level of proanthocyanidins was found in the stem peels extract The peroxidase and catalase activities of stem peel extract were higher than those of the leaf extract The findings showed that the leaf and stem peel extracts of C. gileadensis exhibited significant antibacterial activity against the test organisms. The min. inhibitory concentrations for the plant extracts were compared with the standard reference drug Augmentin but the time-kill curves for the C. gileadensis extracts showed that they were less effective than Augmentin. Moreover, the stem peel extract exhibited stronger antibacterial activity than the leaf extract In conclusion, C. gileadensis can be an important source of natural antioxidants, used as a healthy chewing stick for teeth brushing and oral hygiene purposes. This study involved multiple reactions and reactants, such as 2-Ethylhexyl benzoate (cas: 5444-75-7Reference of 5444-75-7).

2-Ethylhexyl benzoate (cas: 5444-75-7) 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 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. Reference of 5444-75-7

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