Month: January 2023

Effect of Monochamus galloprovincialis feeding on Pinus pinaster and Pinus pinea, oleoresin and insect volatiles was written by Goncalves, Elsa;Figueiredo, A. Cristina;Barroso, Jose G.;Henriques, Joana;Sousa, Edmundo;Bonifacio, Luis. And the article was included in Phytochemistry (Elsevier) in 2020.Product Details of 659-70-1 This article mentions the following:

In Portugal, the pine black sawyer Monochamus galloprovincialis is the principal vector of the pinewood nematode, Bursaphelenchus xylophilus, the causal agent of pine wilt disease (PWD), a lethal phyopathogen with major ecol. and economic consequences to European forestry. The aim of this study was to determine the influence of M. galloprovincialis feeding on the volatiles emitted by pine trees. This study focused on the pine species which are most relevant to Portugal, i.e., Pinus pinaster (maritime pine) and Pinus pinea (stone or umbrella pine), assessing to what extent pine chemotypes might influence feeding by the insect vector. Preliminary evaluation of each maritime pine essential oil allowed recognizing the existence of two main chemotypes (C1 and C2) and absence of chem. variability in P. pinea. Emission of volatiles from pine trees was evaluated before and during 24 h of feeding by a mixed-sex pair of newly emerged, unfed M. galloprovincialis. Volatiles were also collected from the oleoresin released from the feeding wounds as well as from the insects after feeding. Pine volatiles were collected by solid phase microextraction (SPME) and insect volatiles extracted with pentane, and all analyzed by gas chromatog.-mass spectrometry (GC-MS) and by GC for component identification and quantification, resp. Of the seventeen emitted volatiles detected in SPME analyses of P. pinaster, β-pinene, α-pinene, β-caryophyllene, and germacrene D showed the highest average fold increases as a result of M. galloprovincialis feeding. When grouped by P. pinaster chemotype, C1 and C2 groups of trees showed different patterns of responses. β-Caryophyllene and germacrene D showed the highest fold increase in C1 trees, whereas β-pinene and α-pinene clearly dominated in C2 trees. Likewise, the oleoresin volatiles from C1 trees were dominated by δ-3-carene and/or β-pinene, whereas α-pinene and β-pinene were the main volatile components from oleoresin of C2 trees. Nine components were detected in P. pinea volatiles, of which limonene showed the highest fold increase as a result of insect feeding. The volatiles collected from the insects after they had fed on P. pinaster included α-pinene, β-pinene, and abietic acid, and by the straight-chain n-alkanes n-C27, n-C29, and n-C25, together with the methyl-branched hydrocarbons 3-meC29, 2-meC28, and 3-meC27. A better understanding of the responses of different P. pinaster chemotypes to feeding by M. galloprovincialis may be helpful in the development of new lures to improve pine sawyer trapping in integrated pest management for control of PWD. In the experiment, the researchers used many compounds, for example, Isopentyl 3-methylbutanoate (cas: 659-70-1Product Details of 659-70-1).

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. 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.Product Details of 659-70-1

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

Synthesis of (E)-azomethines from 4-aminobenzenesulfonamide (streptocide) derivatives was written by Dikusar, E. A.;Petkevich, S. K.;Potkin, V. I.;Stepin, S. G.. And the article was included in Vestsi Natsyyanal’nai Akademii Navuk Belarusi, Seryya Khimichnykh Navuk in 2015.Reference of 20665-85-4 This article mentions the following:

Synthesis of (E)-azomethines, derivatives of 4-aminobenzenesulfonamide (Streptocidum), by condensation of substituted vanillin-like benzaldehydes with streptocide in methanol, has been described. In the experiment, the researchers used many compounds, for example, 4-Formyl-2-methoxyphenyl isobutyrate (cas: 20665-85-4Reference of 20665-85-4).

4-Formyl-2-methoxyphenyl isobutyrate (cas: 20665-85-4) 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. 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 20665-85-4

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

Targeted and suspect screening of plasticizers in house dust to assess cumulative human exposure risk was written by Demirtepe, Hale;Melymuk, Lisa;Codling, Garry;Murinova, Lubica Palkovicova;Richterova, Denisa;Rasplova, Vladimira;Trnovec, Tomas;Klanova, Jana. And the article was included in Science of the Total Environment in 2021.Application In Synthesis of Dicyclohexyl phthalate This article mentions the following:

Indoor dust is an important exposure route to anthropogenic chems. used in consumer products. Plasticizers are common product additives and can easily leach out of the product and partition to dust. Investigations of plasticizers typically focus on a subset of phthalate esters (PEs), but there are many more PEs in use, and alternative plasticizers (APs) are seeing greater use after recognition of adverse health effects of PEs. In this study we use full scan high resolution mass spectrometry for targeted and suspect screening of PEs and APs in house dust and to assess the potential risk of human exposure. House dust samples from Eastern Slovakia were investigated and concentrations of âˆ?sub>12PEs and âˆ?sub>5APs ranged 12-2765μg/g and 45-13,260μg/g, resp. APs were at similar levels to PEs, indicating common usage of these compounds in products in homes. Evaluation of individual compound toxicity combined with human intake via dust ingestion suggested PEs are of lower priority compared to semivolatile organic compounds such as polychlorinated biphenyls due to their lower toxicity. However, cumulative risk assessment (CRA) is a more appropriate evaluation of risk, considering the presences of many PEs in dust and their similar toxic mode of action. CRA based on median toxicity reference values (TRVs) suggested acceptable risks for dust ingestion, however, the wide range of literature-derived TRVs is a large uncertainty, especially for the APs. Use of newer TRVs suggest risk from dust ingestion alone, i.e. not even considering diet, inhalation, and dermal contact. Addnl., screening of full-scan instrumental spectra identified a further 40 suspect PE compounds, suggesting the CRA based on the 12 target PEs underestimates the risk. In the experiment, the researchers used many compounds, for example, Dicyclohexyl phthalate (cas: 84-61-7Application In Synthesis of Dicyclohexyl phthalate).

Dicyclohexyl phthalate (cas: 84-61-7) 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. 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.Application In Synthesis of Dicyclohexyl phthalate

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

Reaction of alkyl malonates with nitric acid was written by Glowczyk, Joanna;Lange, Jerzy;Abramski, Jan W.. And the article was included in Roczniki Chemii in 1977.Product Details of 10203-58-4 This article mentions the following:

The title reaction with fuming HNO₃ gave RC(NO₂)(CO₂Et)₂ (I; R = Me, Et, Me₂CH, Bu, Me₂CHCH₂, Me₃C) and RC(OH)(CO₂Et)₂ (II); the ratio I–II depended on the temperature At low temperature II was favored and at high temperature I was favored. The degree of conversion depended on R. In the experiment, the researchers used many compounds, for example, Diethyl isobutylmalonate (cas: 10203-58-4Product Details of 10203-58-4).

Diethyl isobutylmalonate (cas: 10203-58-4) 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 10203-58-4

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

Comparative metabolome classification of desert truffles Terfezia claveryi and Terfezia boudieri via its aroma and nutrients profile was written by Farag, Mohamed A.;Fathi, Doaa;Shamma, Samir;Shawkat, Mohamed Sherif A.;Shalabi, Sohir M.;El Seedi, Hesham R.;Afifi, Sherif M.. And the article was included in LWT–Food Science and Technology in 2021.Category: esters-buliding-blocks This article mentions the following:

Desert truffles are popular ectomycorrhizal fungi valued worldwide for their nutritional and traditional health benefits. Herein, two chief desert truffles viz., Terfezia claveryi and T. boudieri were assessed for their metabolites heterogeneity in context of their volatile sensory and nutrients profile as analyzed via GC-MS. Primary metabolites accounting for nutritive indexes in T. claveryi and T. boudieri were investigated with 61 peaks belonging to sugars, sugar alcs. and amino acids. After headspace solid-phase microextraction (HS-SPME), a total of 106 volatiles were annotated belonging to alcs., ketones, aldehydes, esters, ethers and furans. The abundance of oxygenated monoterpenes as antimicrobials rationalizes for the folk use of desert truffles against trachoma. Benzyl isothiocyanate was detected as the sulfur containing volatile component in desert truffle and absent from truffles. Multivariate data analyses (MVA) revealed that 1-octen-3-ol and 3-octanone were the most significantly contributors in the discrimination of T. claveryi and T. boudieri specimens. Being more enriched in essential amino acids, T. claveryi provided a better sugar diet composition concurrent with lower sugars and higher sugar alcs. compared to T. boudieri. This study provides the first insight into desert truffles metabolites and sensory composition, and to account for its culinary and medicinal uses. In the experiment, the researchers used many compounds, for example, 5-Ethyldihydrofuran-2(3H)-one (cas: 695-06-7Category: esters-buliding-blocks).

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. 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

Flavor characterization of native Peruvian chili peppers through integrated aroma fingerprinting and pungency profiling was written by Morales-Soriano, Eduardo;Kebede, Biniam;Ugas, Roberto;Grauwet, Tara;Van Loey, Ann;Hendrickx, Marc. And the article was included in Food Research International in 2018.Product Details of 659-70-1 This article mentions the following:

A broad range of Peruvian chili peppers are available but not properly characterized. To increase the insight into their flavor compounds, a head space GC-MS fingerprinting (volatiles) and an HPLC-based profiling approach (pungency) was implemented to characterize twenty landraces (Capsicum annuum, C. baccatum and C. chinense). The data obtained was analyzed with powerful chemometric approaches to identify unique flavor compounds for each of the species and for each of the landraces within a specific species. The pungency profile and volatiles such as esters, terpenes and norcarotenoids distinguish Cerezo triangular (4) (C. annuum). Mainly esters provoked the separation between Chico (42), Cacho de cabra rojo (323), Amarillo de Chachapoyas (318) (C. baccatum), Arnaucho (60) and Miscucho amarillo (69) (C. chinense). This study demonstrates the potential of the integrated fingerprinting, profiling and a chemometric approach to extensively understand the unique flavor compounds in Peruvian chili peppers. In the experiment, the researchers used many compounds, for example, Isopentyl 3-methylbutanoate (cas: 659-70-1Product Details of 659-70-1).

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.Product Details of 659-70-1

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

Kinetic Diastereomer Differentiation in Au(III)- and Bi(III)-Catalyzed Benzylic Arylation: Concise and Stereocontrolled Synthesis of 2-Amino-1,1-diarylalkanes was written by Chenard, Etienne;Hanessian, Stephen. And the article was included in Organic Letters in 2014.Application In Synthesis of (S)-tert-Butyl (1-(methoxy(methyl)amino)-1-oxo-3-phenylpropan-2-yl)carbamate This article mentions the following:

2-Nitro- and 2-azido-1,1-diarylalkanes with electron-donating aryl groups such as I [R = 2,4-(MeO)₂C₆H₃, 4-methoxy-1-naphthyl, 4-MeOC₆H₄, 2,3,4-(MeO)₃C₆H₂, 5-methyl-2-furyl, 2,6-(MeO)₂-4-(H₂C:CH)C₆H₂; R¹ = H, Me, Et, n-Pr, i-Pr, allyl, PhCH₂; R² = O₂N, N₃] were prepared diastereoselectively as their syn diastereomers in 14-91% yields (all but one > 50% yields) and in 5:1->20:1 diastereoselectivities by nucleophilic substitution of benzylic alcs. such as I (R = HO; R¹ = H, Me, Et, n-Pr, i-Pr, allyl, PhCH₂; R² = O₂N, N₃) with arenes in the presence of either AuCl₃ or Bi(OTf)₃; an azidotosylamide I (R = TsNH; R¹ = Et; R² = O₂N; Ts = 4-MeC₆H₄SO₂) was prepared using TsNH₂ as a nucleophile instead of an arene. Nonracemic benzyl alcs. were prepared from phenylalanine and incorporated into nonracemic diarylalkyl azides; variation of the aryl group in the nitroalkyl and azidoalkyl benzyl alcs. allowed access in some cases to both syn- and anti-diastereomers of diarylalkyl azido and nitro compounds Kinetic resolution occurred in reactions of diastereomeric mixtures of nitro alcs., with the syn diastereomers of the reactants converted more rapidly to the corresponding products than the anti-diastereomers; both diastereomeric alcs. yielded the syn product. The structure of I (R = 4-MeO-1-naphthyl; R¹ = Et; R² = O₂N) was determined by X-ray crystallog. In the experiment, the researchers used many compounds, for example, (S)-tert-Butyl (1-(methoxy(methyl)amino)-1-oxo-3-phenylpropan-2-yl)carbamate (cas: 87694-53-9Application In Synthesis of (S)-tert-Butyl (1-(methoxy(methyl)amino)-1-oxo-3-phenylpropan-2-yl)carbamate).

(S)-tert-Butyl (1-(methoxy(methyl)amino)-1-oxo-3-phenylpropan-2-yl)carbamate (cas: 87694-53-9) belongs to esters. 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. Many esters have the potential for conformational isomerism, but they tend to adopt an s-cis (or Z) conformation rather than the s-trans (or E) alternative, due to a combination of hyperconjugation and dipole minimization effects. The preference for the Z conformation is influenced by the nature of the substituents and solvent, if present. Lactones with small rings are restricted to the s-trans (i.e. E) conformation due to their cyclic structure.Application In Synthesis of (S)-tert-Butyl (1-(methoxy(methyl)amino)-1-oxo-3-phenylpropan-2-yl)carbamate

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

Copper-Catalyzed Cross-Coupling of Thiols, Alcohols, and Oxygen for the Synthesis of Esters was written by Lim, Seungyeon;Ji, Miran;Wang, Xi;Lee, Chan;Jang, Hye-Young. And the article was included in European Journal of Organic Chemistry in 2015.SDS of cas: 27249-90-7 This article mentions the following:

Copper-catalyzed, one-pot, three-component coupling reactions using thiols, alcs., and oxygen to form a variety of esters in good yields were studied. In the presence of easily oxidized benzylic and allylic alcs., thiols were selectively oxidized to form thionoesters, which underwent facile S/O exchange to afford esters. Thiols may be used as an alternative benzoyl source under mild aerobic conditions. In the experiment, the researchers used many compounds, for example, Benzyl benzodithioate (cas: 27249-90-7SDS of cas: 27249-90-7).

Benzyl benzodithioate (cas: 27249-90-7) 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. 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.SDS of cas: 27249-90-7

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

Studies on ketene and its derivatives. CX. Synthesis of 1,3-dimethoxyfluoren-9-ones was written by Nakano, Jun;Katagiri, Nobuya;Kato, Tetsuzo. And the article was included in Chemical & Pharmaceutical Bulletin in 1982.Quality Control of Ethyl 3-oxo-3-(m-tolyl)propanoate This article mentions the following:

1,3-Dimethoxyfluoren-9-ones (I; R, R² = H, Me, MeO; R¹ = H; R¹R² = benzo) were prepared from dihydroxybenzoates (II; R = H, R⁴ = EtO) (III). Thus, cyclocondensation of diketene with Et 3-aryl-3-oxopropionates in the presence of NaH in THF gave III, which were treated with MeI followed by alc. NaOH to give II (R³ = Me, R⁴ = HO) (IV). Cyclization of IV with (CF₃CO)₂O gave I. In the experiment, the researchers used many compounds, for example, Ethyl 3-oxo-3-(m-tolyl)propanoate (cas: 33166-79-9Quality Control of Ethyl 3-oxo-3-(m-tolyl)propanoate).

Ethyl 3-oxo-3-(m-tolyl)propanoate (cas: 33166-79-9) belongs to esters. Esters are widespread in nature and are widely used in industry. In nature, fats are in general triesters derived from glycerol and fatty acids. Esters are responsible for the aroma of many fruits. 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.Quality Control of Ethyl 3-oxo-3-(m-tolyl)propanoate

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

Dynamic Kinetic Resolution Enabled by Intramolecular Benzoin Reaction: Synthetic Applications and Mechanistic Insights was written by Zhang, Guoxiang;Yang, Shuang;Zhang, Xiaoyan;Lin, Qiqiao;Das, Deb. K.;Liu, Jian;Fang, Xinqiang. And the article was included in Journal of the American Chemical Society in 2016.Related Products of 33166-79-9 This article mentions the following:

The highly enantio-, diastereo-, and regioselective dynamic kinetic resolution of β-ketoesters and 1,3-diketones was achieved via a chiral N-heterocyclic carbene catalyzed intramol. cross-benzoin reaction. A variety of tetralone derivatives bearing two contiguous stereocenters and multiple functionalities were liberated in moderate to excellent yields and with high levels of stereoselectivity (>95% ee and >20:1 dr in most cases). In addition, the excellent regioselectivity control for aryl/alkyl 1,3-diketones, and the superior electronic differentiation of 1,3-diarylketones were highlighted. Moreover, a set of new mechanistic rationale that differs with the currently widely accepted understanding of intramol. benzoin reactions was established to demonstrate the superior preference of benzoin over aldol transformation. A coexistence of competitive aldol and benzoin reactions was detected, but a retro-aldol-irreversible benzoin process performs a vital role in the generation of predominant benzoin products. The most essential role of an N-electron-withdrawing substituent in triazolium catalysts was revealed to be accelerating the rate of the benzoin transformation, rather than suppressing the aldol process through reducing the inherent basicity of the catalyst. In the experiment, the researchers used many compounds, for example, Ethyl 3-oxo-3-(m-tolyl)propanoate (cas: 33166-79-9Related Products of 33166-79-9).

Ethyl 3-oxo-3-(m-tolyl)propanoate (cas: 33166-79-9) 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. 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.Related Products of 33166-79-9

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