Tag: 100-200

One-dimensional optoelectronic nanostructures derived from the aqueous self-assembly of π-conjugated oligopeptides was written by Diegelmann, Stephen R.;Gorham, Justin M.;Tovar, John D.. And the article was included in Journal of the American Chemical Society in 2008.COA of Formula: C7H8O2S This article mentions the following:

The aqueous self-assembly of oligopeptide-flanked π-conjugated mols. into discrete one-dimensional nanostructures is described. Unique to these mols. is the fact that the π-conjugated unit has been directly embedded within the peptide backbone by way of a synthetic amino acid with π-functionality that is compatible with standard Fmoc-based (Fmoc = 9-fluorenylmethoxycarbonyl) peptide synthesis. The peptide-based mol. design enforces intimate π-π communication within the aggregate after charge-screening and self-assembly, making these nanostructures attractive for optical or electronic applications in biol. environments. The synthesis and assembly are reported along with spectroscopic and morphol. characterization of the new nanomaterials. In the experiment, the researchers used many compounds, for example, Methyl 2-thienylacetate (cas: 19432-68-9COA of Formula: C7H8O2S).

Methyl 2-thienylacetate (cas: 19432-68-9) 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.COA of Formula: C7H8O2S

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

Periodically Clickable Polyesters: Study of Intrachain Self-Segregation Induced Folding, Crystallization, and Mesophase Formation was written by Mandal, Joydeb;Krishna Prasad, S.;Rao, D. S. Shankar;Ramakrishnan, S.. And the article was included in Journal of the American Chemical Society in 2014.Computed Properties of C10H14O4 This article mentions the following:

A series of polyesters based on 2-propargyl-1,3-propanediol or 2,2-dipropargyl-1,3-propanediol or 2-allyl-2-propargyl-1,3-propanediol and 1,20-eicosanedioic acid were prepared by solution polycondensation using the corresponding diacid chloride; these polyesters were quant. “clicked” with a fluoroalkyl azide, namely CF₃(CF₂)₇CH₂CH₂N₃, to yield polyesters carrying long-chain alkylene segments in the backbone and either one or two perfluoroalkyl segments located at periodic intervals along the polymer chain. The immiscibility of the alkylene and fluoroalkyl segments causes the polymer chains to fold in a zigzag fashion to facilitate the segregation of these segments; the folded chains further organize in the solid state to form a lamellar structure with alternating domains of alkyl (HC) and fluoroalkyl (FC) segments. Evidence for the self-segregation is provided by DSC, SAXS, WAXS, and TEM studies; in two of the samples, the DSC thermograms showed two distinct endotherms associated with the melting of the individual domains, while the WAXS patterns confirm the existence of two sep. peaks corresponding to the interchain distances within the crystalline lattices of the HC and FC domains. SAXS data, on the other hand, reveal the formation of an extended lamellar morphol. with an interlamellar spacing that matches reasonably well with those estimated from TEM studies. Interestingly, a smectic-type liquid crystalline phase is observed at temperatures between the two melting transitions. These systems present a unique opportunity to develop interesting nanostructured polymeric materials with precise control over both the domain size and morphol.; importantly, the domain sizes are far smaller than those typically observed in traditional block copolymers. In the experiment, the researchers used many compounds, for example, Diethyl 2-(prop-2-yn-1-yl)malonate (cas: 17920-23-9Computed Properties of C10H14O4).

Diethyl 2-(prop-2-yn-1-yl)malonate (cas: 17920-23-9) 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. 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 C10H14O4

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

Volatolomics approach by HS-SPME-GC-MS and multivariate analysis to discriminate olive tree varieties infected by Xylella fastidiosa was written by Mentana, Annalisa;Camele, Ippolito;Mang, Stefania M.;De Benedetto, Giuseppe E.;Frisullo, Salvatore;Centonze, Diego. And the article was included in Phytochemical Analysis in 2019.Category: esters-buliding-blocks This article mentions the following:

Xylella fastidiosa (Xf) is a pathogenic bacterium that causes diseases in olive trees. Therefore, anal. methods for both the characterization of the host/pathogen interaction and infection monitoring are needed. Volatile organic compounds (VOCs) are emitted by plants relate to their physiol. state, therefore VOCs monitoring can assist in detecting stress or infection states before visible signs are present. In this work, the headspace-solid phase microextraction-gaschromatog.-mass spectrometry (HS-SPME-GC-MS) technique was used for the first time to highlight VOCs differences between healthy and Xf-infected olive trees. VOCs from olive tree twig samples were extracted and analyzed by HS-SPME-GC-MS, and hence identified by comparing the exptl. linear retention indexes with the reference values and by MS data obtained from NIST library. Data were processed by principal component anal. (PCA) and anal. of variance (ANOVA). The HS-SPME step was optimized in terms of adsorbent phase and extraction time. HS-SPME-GC-MS technique was applied to the extraction and anal. of VOCs of healthy and Xf-infected olive trees. More than 100 compounds were identified and the differences between samples were evidenced by the multivariate anal. approach. The results showed the marked presence of Me esters in Xf-infected samples, suggesting their probable involvement in the mechanism of diffusible signal factor. The proposed approach represents an easy and solvent-free method to evaluate the presence of Xf in olive trees, and to evidence volatiles produced by host/pathogen interactions that could be involved in the defensive mechanism of the olive tree and/or in the infective action of Xf. In the experiment, the researchers used many compounds, for example, Methyl2-methylbutyrate (cas: 868-57-5Category: esters-buliding-blocks).

Methyl2-methylbutyrate (cas: 868-57-5) 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.Category: esters-buliding-blocks

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

Physiological activity of Chinese lichen (Gyrophora esculenta) component, methyl 2,4-dihydroxy-6-methylbenzoate and the related compounds was written by Wu, Shuhsien;Zhao, Zhendong;Okada, Yoshiharu;Watanabe, Yoshiyuki;Takahata, Toshiyuki;Inoue, Toshio;Otsubo, Eiji;Wang, Jing;Lu, Yanju;Nomura, Masato. And the article was included in Asian Journal of Chemistry in 2014.Quality Control of Methyl 4-Hydroxy-2-methoxybenzoate This article mentions the following:

It was confirmed that there was a higher expression of antioxidant potential in Me 2,4-dihydroxy-6-methylbenzoate (orsellinic acid Me ester) (2), which was isolated from methanol extract oil of Chinese lichen Gyrophora esculenta rather than from commercialized ascorbic acid. Taking this into account, 4 types of compounds-(4-7) which are known to be related to compound (2)-have been synthesized by using 2,4-dihydroxy benzoic acid (3) as starting material. After that, some physiol. activity tests on these compounds have been conducted in the following aspects: antioxidant potential, cytotoxicity, cytokine suppressant effect and histamine liberation inhibition and the effects have been evaluated, resp. The result shows that (2) and Me 2,4-dihydroxybenzoate (4) showed high radical expression in both antioxidant potential and histamine liberation inhibition. It was also found that none of these compounds expresses cytotoxicity. In the experiment, the researchers used many compounds, for example, Methyl 4-Hydroxy-2-methoxybenzoate (cas: 28478-46-8Quality Control of Methyl 4-Hydroxy-2-methoxybenzoate).

Methyl 4-Hydroxy-2-methoxybenzoate (cas: 28478-46-8) 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.Quality Control of Methyl 4-Hydroxy-2-methoxybenzoate

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

Chemical Diversity of Citrus Leaf Essential Oils was written by Clery, Robin A.;Armendi, Anjo;Franco, Veronica;Furrer, Stefan;Genereux, Joseph C.;Kahn, Tracy L.;Koshiro, Kevin. And the article was included in Chemistry & Biodiversity in 2022.Name: (E)-3,7-Dimethylocta-2,6-dien-1-yl acetate This article mentions the following:

The essential oils from leaves of 20 com. citrus accessions maintained by the University of California, Riverside Givaudan Citrus Variety Collection and selected on the basis of their odor profile were analyzed by GCMS/FID. The main components were quantified while the semi-quant. percentage composition data was compiled with data from other publications for sample visualization, classification and comparison with leaf oils from other citrus accessions. Some compositional clusters aligned closely with the taxonomic clades of sweet orange, bitter orange, and C. hystrix while other clades like the mandarins and lemons showed distinct chem. sub-groups. Characteristic compounds for the clusters included linalyl acetate and linalool (bitter orange leaf), sabinene (sweet orange leaf), Me N-Me anthranilate (mandarin leaf), γ-terpinene (yuzu leaf), citronellal (C. hystrix), limonene, citronellal and citral (lemons and citrons). A chemometric approach combined with t-SNE cluster plots can be more informative than taxonomic assignments when considering flavor and fragrance characteristics. In the experiment, the researchers used many compounds, for example, (E)-3,7-Dimethylocta-2,6-dien-1-yl acetate (cas: 105-87-3Name: (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 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. Name: (E)-3,7-Dimethylocta-2,6-dien-1-yl acetate

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

Insight into aroma dynamic changes during the whole manufacturing process of chestnut-like aroma green tea by combining GC-E-Nose, GC-IMS, and GC x GC-TOFMS was written by Yang, Yanqin;Qian, Michael C.;Deng, Yuliang;Yuan, Haibo;Jiang, Yongwen. And the article was included in Food Chemistry in 2022.Recommanded Product: 118-61-6 This article mentions the following:

Processing is the crucial factor for green tea aroma quality. In this study, the aroma dynamic changes throughout the manufacturing process of chestnut-like aroma green tea were investigated with gas chromatog. electronic nose (GC-E-Nose), gas chromatog.-ion mobility spectrometry (GC-IMS), and comprehensive two-dimensional gas chromatog. coupled to time-of-flight mass spectrometry (GC x GC-TOFMS). GC-IMS identified 33 volatile compounds while GC x GC-TOFMS identified 211 volatile components. Drying exerted the greatest influence on the volatile components of chestnut-like aroma green tea, and promoted the generation of heterocyclic compounds and sulfur compounds which were commonly generated via the Maillard reaction during the roasting stage. A large number of heterocyclic compounds such as 1-methyl-1H-pyrrole, pyrrole, methylpyrazine, furfural, 2-ethyl-5-methylpyrazine, 1-ethyl-1H-pyrrole-2-carboxaldehyde, and 3-acetylpyrrole were newly formed during the drying process. This study also validated the suitability of GC-E-Nose combined with GC-IMS and GC x GC-TOFMS for tracking the changes in volatile components of green tea throughout the manufacturing process. In the experiment, the researchers used many compounds, for example, Ethyl 2-hydroxybenzoate (cas: 118-61-6Recommanded Product: 118-61-6).

Ethyl 2-hydroxybenzoate (cas: 118-61-6) 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: 118-61-6

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

Wild Harenna coffee: flavour profiling from the bean to the cup was written by Ascrizzi, Roberta;Flamini, Guido. And the article was included in European Food Research and Technology in 2020.Computed Properties of C10H20O2 This article mentions the following:

As one of the last places where coffee grows spontaneously, the Harenna forest (Ethiopia) is the origin of the coffee analyzed in this study. The anal. of the volatile emission of each processing phase evaluates the chem. fingerprint of the reactions taking place at each stage, leading to the final aroma. The green beans mainly emit non-terpene esters and alkanes. Once the roasting begins, monoterpenes are the main class until 160°C: at this point, 2,6-dimethylpyrazine prevails in the headspaces, as main product of the Maillard reactions. This compound, with its sweet and nut-like aroma, is also detected in the brewed coffee. The shed silverskins are rich in Me chavicol and retain the monoterpenes on the beans: as these compounds are important aroma contributors, the removal of the silverskins prior to roasting seems non-advisable. The grinding of the samples breaks the matrixes and leads to drastic changes in the volatile emissions. In the experiment, the researchers used many compounds, for example, Isopentyl 3-methylbutanoate (cas: 659-70-1Computed Properties of C10H20O2).

Isopentyl 3-methylbutanoate (cas: 659-70-1) belongs to esters. Esters typically have a pleasant smell; those of low molecular weight are commonly used as fragrances and are found in essential oils and pheromones. Liquid esters of low volatility serve as softening agents for resins and plastics. Esters also include many industrially important polymers. Polymethyl methacrylate is a glass substitute sold under the names Lucite and Plexiglas; polyethylene terephthalate is used as a film (Mylar) and as textile fibres sold as Terylene, Fortrel, and Dacron.Computed Properties of C10H20O2

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

Characterization of odor-active volatile compounds of jambolan [Syzgium cumini (L.) Skeels] wine was written by Pino, Jorge A.;Espinosa, Sixsy;Duarte, Cira. And the article was included in Journal of Food Science and Technology (New Delhi, India) in 2022.Computed Properties of C10H20O2 This article mentions the following:

Volatile constituents in jambolan [Syzgium cumini (L.) Skeels] wine were isolated by headspace-solid phase microextraction (HS-SPME) and analyzed by gas chromatog.-flame ionization detector (GC-FID), gas chromatog.-mass spectrometry (GC-MS), and gas chromatog.-olfactometry (GC-O). The composition of the jambolan wine included 52 esters, 20 terpenes, 13 alcs., 12 acids, 11 aldehydes, 4 ketones, 4 oxides, and 5 miscellaneous compounds Aroma extract dilution anal. and odor activity units were used for the determination of odor-active compounds A total of 19 odor-active compounds were found as odor-active volatiles, from which (E)-β-ionone, phenylacetaldehyde, Et acetate, Et hexanoate, and Et benzoate were the most important. The similar results of the GC-O and OAV approaches suggests that HS-SPME-GC-O could be used as a fast and simple tool to quality control of the jambolan wine aroma. In the experiment, the researchers used many compounds, for example, Isopentyl 3-methylbutanoate (cas: 659-70-1Computed Properties of C10H20O2).

Isopentyl 3-methylbutanoate (cas: 659-70-1) 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.Computed Properties of C10H20O2

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

Characterization of key odor-active compounds in commercial high-salt liquid-state soy sauce by switchable GC/GC x GC-olfactometry-MS and sensory evaluation was written by Wang, Xiaojun;Guo, Mengyao;Song, Huanlu;Meng, Qi;Guan, Xiaosheng. And the article was included in Food Chemistry in 2021.Application In Synthesis of 5-Hexyldihydrofuran-2(3H)-one This article mentions the following:

Activity of odor compounds of soy sauces has not been fully determined so far. Herein, a new switchable GC/GC x GC-olfactometry-mass spectrometry system for simultaneous GC x GC-MS anal. and sniffing of each odor-active substance through a single injection was used for the aroma extract dilution anal. of five regular high-salt liquid-state soy sauces (HLS). Methional, maltol, guaiacol, 4-ethylguaiacol, 2-acetylpyrrole, 2-acetylfuran, 2-phenylethanol, and 4-hydroxy-2,5-dimethyl-3(2H)-furanone showed high flavor dilution (FD) factors. The FD factors of all odor-active compounds in different odor attributes were summed up (score) to evaluate the odor characteristics of the samples. Cooked potato-like odor was the most important characteristic. The difference in the odor characteristics were mainly reflected in the balance of caramel-like/sweet, roasted/roasted nut-like, spicy/burnt, and unpleasant odor intensity; the fruity odor intensity was the weakest. This study will provide a better understanding of the odor characteristics and key odor-active compounds in Chinese regular com. HLS. In the experiment, the researchers used many compounds, for example, 5-Hexyldihydrofuran-2(3H)-one (cas: 706-14-9Application In Synthesis of 5-Hexyldihydrofuran-2(3H)-one).

5-Hexyldihydrofuran-2(3H)-one (cas: 706-14-9) 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.Application In Synthesis of 5-Hexyldihydrofuran-2(3H)-one

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

Combination of epigallocatechin gallate with L-cysteine in inhibiting Maillard browning of concentrated orange juice during storage was written by Chen, Yangyang;Zhang, Min;Mujumdar, Arun S.;Liu, Yaping. And the article was included in LWT–Food Science and Technology in 2022.Safety of (E)-3,7-Dimethylocta-2,6-dien-1-yl acetate This article mentions the following:

Orange juice is popular with consumers because of its unique taste, flavor as well as nutritional value which accounts for a large proportion of the global juice market. Concentrated orange juice (COJ), undergoes browning during storage seriously affecting its quality and com. This study was the first to evaluate the effects of epigallocatechin gallate (EGCG) and L-cysteine (L-cys) on Maillard browning of COJ during storage. The results show that EGCG and L-cys reduce significantly the production of 5-hydroxymethylfurfural (5-HMF), the characteristic product of Maillard reaction (MR), and the combined use of EGCG and L-cys was even more effective. Furthermore, the color of the treated COJ displayed negligible change after storage, with higher L* and b* values and marginally lower a* values. The flavor, taste, main volatile substances as well as rheol. properties of the treated COJ were also determined; none of these properties were affected adversely during storage. This treatment method ensures that the key sensory quality and material properties of COJ are preserved by the proposed treatment while inhibiting Maillard browning during storage. In the experiment, the researchers used many compounds, for example, (E)-3,7-Dimethylocta-2,6-dien-1-yl acetate (cas: 105-87-3Safety 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. 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.Safety of (E)-3,7-Dimethylocta-2,6-dien-1-yl acetate

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