Month: February 2023

Efficient Syntheses of Rugulosin Analogues was written by Snider, Barry B.;Gao, Xiaolei. And the article was included in Journal of Organic Chemistry in 2005.Quality Control of Methyl 2-methoxy-4-methylbenzoate This article mentions the following:

Oxidation of anthracen-1-ones I (R = OH, R¹ = H; R = R¹ = Me; R = CH₂OAc, R¹ = Me) with Pb(OAc)₄ in AcOH for 20 min at 25鎺矯 and 1 h at 75鎺矯 gave flavoskyrin-type dimers, e.g. II, in 53-86% yield. Heating a solution of the flavoskyrin-type dimers in pyridine under air for 1 h at 75-80鎺矯 and then for 1-2 h at 110鎺矯 afforded rugulosin-type dimers, e.g. III, in 61-88% yield. This two-step sequence provides a practical route to this unusual natural product skeleton. In the experiment, the researchers used many compounds, for example, Methyl 2-methoxy-4-methylbenzoate (cas: 81245-24-1Quality Control of Methyl 2-methoxy-4-methylbenzoate).

Methyl 2-methoxy-4-methylbenzoate (cas: 81245-24-1) 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. Esters contain a carbonyl center, which gives rise to 120鎺?C閳ユ弲閳ユ彊 and O閳ユ弲閳ユ彊 angles. Unlike amides, esters are structurally flexible functional groups because rotation about the C閳ユ彊閳ユ弲 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. Quality Control of Methyl 2-methoxy-4-methylbenzoate

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

Probing the Role of the C-H璺矾璺疧 Hydrogen Bond Stabilized Polypeptide Chain Reversal at the C-terminus of Designed Peptide Helices. Structural Characterization of Three Decapeptides was written by Aravinda, Subrayashastry;Shamala, Narayanaswamy;Bandyopadhyay, Abhishek;Balaram, Padmanabhan. And the article was included in Journal of the American Chemical Society in 2003.Product Details of 133467-01-3 This article mentions the following:

The structural characterization in crystals of three designed decapeptides containing a double D-segment at the C-terminus is described. The crystal structures of the peptides Boc-Leu-Aib-Val-Xaa-Leu-Aib-Val-^DAla-^DLeu-Aib-OMe, (peptides 2, 3, 4 have Xaa = Gly , ^DAla , Aib, resp.) have been determined and compared with those reported earlier for peptide 1 (Xaa = Ala) and the all L analog Boc-Leu-Aib-Val-Ala-Leu-Aib-Val-Ala-Leu-Aib-OMe, which yielded a perfect right-handed 浼?helical structure. Peptides 1 and 2 reveal a right-handed helical segment spanning residues 1 to 7, ending in a Schellman motif with ^DAla(8) functioning as the terminating residue. Polypeptide chain reversal occurs at residue 9, a novel feature that appears to be the consequence of a C-H璺矾璺疧 hydrogen bond between residue 4 C^{浼?/sup>H and residue 9 CO groups. The structures of peptides 3 and 4, which lack the pro R hydrogen at the C浼?/sup> atom of residue 4, are dramatically different. Peptide 3 adopts a right-handed helical conformation over the 1 to 7 segment. Residues 8 and 9 adopt 浼?sub>L conformations forming a C-terminus type I’ 灏?turn, corresponding to an incipient left-handed twist of the polypeptide chain. In peptide 4, helix termination occurs at Aib(6), with residues 6 to 9 forming a left-handed helix, resulting in a structure that accommodates direct fusion of two helical segments of opposite twist. Peptides 3 and 4 provide examples of chiral residues occurring in the less favored sense of helical twist; DAla(4) in peptide 3 adopts an 浼?sub>R conformation, while LVal(7) in 4 adopts an 浼?sub>L conformation. The structural comparison of the decapeptides reported here provides evidence for the role of specific C-H璺矾璺疧 hydrogen bonds in stabilizing chain reversals at helix termini, which may be relevant in aligning contiguous helical and strand segments in polypeptide structures. In the experiment, the researchers used many compounds, for example, Boc-D-Leu-OMe (cas: 133467-01-3Product Details of 133467-01-3).}

Boc-D-Leu-OMe (cas: 133467-01-3) belongs to esters. Volatile esters with characteristic odours are used in synthetic flavours, perfumes, and cosmetics. Certain volatile esters are used as solvents for lacquers, paints, and varnishes. Esters contain a carbonyl center, which gives rise to 120鎺?C閳ユ弲閳ユ彊 and O閳ユ弲閳ユ彊 angles. Unlike amides, esters are structurally flexible functional groups because rotation about the C閳ユ彊閳ユ弲 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. Product Details of 133467-01-3

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

Copper-catalyzed regiodivergent 1,4- and 1,6-conjugate silyl addition to diendioates: access to functionalized allylsilanes was written by Ahmad, Tanveer;Li, Qi;Qiu, Sheng-Qi;Xu, Jian-Lin;Xu, Yun-He;Loh, Teck-Peng. And the article was included in Organic & Biomolecular Chemistry in 2019.Recommanded Product: 1190-39-2 This article mentions the following:

A Cu-catalyzed regioselective 1,4- and 1,6-conjugate addition of a silyl reagent to diendioates was established. Various 1,4- and 1,6-protosilylation products were obtained in good yields and with high regioselectivity via tuning the ligands used in the reactions. This protocol provided a simple and efficient method for the synthesis of multisubstituted functionalized allylsilanes. In the experiment, the researchers used many compounds, for example, malonic acid dibutyl ester (cas: 1190-39-2Recommanded Product: 1190-39-2).

malonic acid dibutyl ester (cas: 1190-39-2) 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 绾?valerolactone.Recommanded Product: 1190-39-2

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

Development of a green alternative vortex-assisted dispersive liquid-liquid microextraction based on natural hydrophobic deep eutectic solvents for the analysis of phthalate esters in soft drinks was written by Santana-Mayor, Alvaro;Herrera-Herrera, Antonio V.;Rodriguez-Ramos, Ruth;Socas-Rodriguez, Barbara;Rodriguez-Delgado, Miguel Angel. And the article was included in ACS Sustainable Chemistry & Engineering in 2021.Quality Control of Dicyclohexyl phthalate This article mentions the following:

A new green alternative vortex-assisted dispersive liquid-liquid microextraction method based on a natural hydrophobic deep eutectic solvent was developed for the extraction of 14 phthalic acid esters and one adipate in cold infusions and tonic waters. Analyses were carried out using ultra-performance liquid chromatog. coupled to tandem mass spectrometry. Different eutectic mixtures based on the monoterpene thymol (essential oil of thyme) and medium-chain fatty acids (octanoic and decanoic acids) at different molar ratios were tested in this regard. The effect of different factors affecting extraction efficiency was optimized through a systematic approach. The method was validated by means of precision, matrix-matched calibration, recovery, and repeatability studies using two different deuterated surrogate standards (di-Bu phthalate-3,4,5,6-d₄ and dihexyl phthalate-3,4,5,6-d₄). The method proved to be linear (determination coefficients were higher than 0.9912) with normalized recoveries in the range between 71 and 124% (except for di-n-octyl phthalate at a low concentration level in tonic water [63%]). Then, the method was applied for the anal. of the selected compounds in 3 pineapple/green tea-based cold infusions and 8 tonic beverages. Finally, the greenness of the procedure was assessed using the Anal. Eco-Scale. This paper represents the first application of this natural hydrophobic deep eutectic solvent for the anal. of phthalate esters, and, also the first time, these compounds are analyzed in cold infusion and tonic water. A green method was developed for the anal. of phthalate esters in soft drinks using natural hydrophobic eutectic solvents. In the experiment, the researchers used many compounds, for example, Dicyclohexyl phthalate (cas: 84-61-7Quality Control of Dicyclohexyl phthalate).

Dicyclohexyl phthalate (cas: 84-61-7) 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.Quality Control of Dicyclohexyl phthalate

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

Substituted 7-Amino-5-thio-thiazolo[4,5-d]pyrimidines as Potent and Selective Antagonists of the Fractalkine Receptor (CX₃CR1) was written by Karlstroem, Sofia;Nordvall, Gunnar;Sohn, Daniel;Hettman, Andreas;Turek, Dominika;Aahlin, Kristofer;Kers, Annika;Claesson, Martina;Slivo, Can;Lo-Alfredsson, Yvonne;Petersson, Carl;Bessidskaia, Galina;Svensson, Per H.;Rein, Tobias;Jerning, Eva;Malmberg, Aasa;Ahlgen, Charlotte;Ray, Colin;Vares, Lauri;Ivanov, Vladimir;Johansson, Rolf. And the article was included in Journal of Medicinal Chemistry in 2013.COA of Formula: C12H23NO4 This article mentions the following:

The authors have developed two parallel series, A and B, of CX₃CR1 antagonists for the treatment of multiple sclerosis. By modifying the substituents on the 7-amino-5-thio-thiazolo[4,5-d]pyrimidine core structure, they were able to achieve compounds with high selectivity for CX₃CR1 over the closely related CXCR2 receptor. The structure-activity relationships showed that a leucinol moiety attached to the core-structure in the 7-position together with 浼?Me branched benzyl derivatives in the 5-position displayed promising affinity, and selectivity as well as physicochem. properties, as exemplified by compounds I and II. They show the preparation of the first potent and selective orally available CX₃CR1 antagonists. In the experiment, the researchers used many compounds, for example, Boc-D-Leu-OMe (cas: 133467-01-3COA of Formula: C12H23NO4).

Boc-D-Leu-OMe (cas: 133467-01-3) 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. Cyclic esters are called lactones, regardless of whether they are derived from an organic or inorganic acid. One example of an organic lactone is 绾?valerolactone.COA of Formula: C12H23NO4

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

Electrochemical Oxidative Cyclization: Synthesis of Polysubstituted Pyrrole from Enamines was written by Chen, Zhiwei;Shi, Guang;Tang, Wei;Sun, Jie;Wang, Wenxing. And the article was included in European Journal of Organic Chemistry in 2021.Safety of Ethyl 3-oxo-3-(m-tolyl)propanoate This article mentions the following:

A conceptually novel method for the preparation of pyrrole is described by electrochem.-oxidation-induced intermol. annulation via enamines. In a simple undivided cell, based on a sodium acetate-facilitated, polysubstituted pyrrole derivations has been facilely synthesized under external oxidant-free condition. This electrosynthetic approach providing an environmentally benign protocol for C-C bond cross-coupling and oxidative annulation, which features unparalleled broad scope of substrates and practicality. In the experiment, the researchers used many compounds, for example, Ethyl 3-oxo-3-(m-tolyl)propanoate (cas: 33166-79-9Safety of Ethyl 3-oxo-3-(m-tolyl)propanoate).

Ethyl 3-oxo-3-(m-tolyl)propanoate (cas: 33166-79-9) 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. Because of their lack of hydrogen-bond-donating ability, esters do not self-associate. Consequently, esters are more volatile than carboxylic acids of similar molecular weight.Safety of Ethyl 3-oxo-3-(m-tolyl)propanoate

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

“Bottom-Up” Fabrication of BODIPY-Functionalized Fluorescent Hyperbranched Glycopolymers for Hepatoma-Targeted Imaging was written by Sun, Pei;Deng, Hongping;Zhou, Linzhu;Wu, Yan;Jin, Xin;Tong, Gangsheng;Yu, Xuemei. And the article was included in Macromolecular Bioscience in 2018.Reference of 4163-60-4 This article mentions the following:

A novel type of multivalent and highly specific fluorescent hyperbranched glycopolymers h-P(GalEA-co-VBPT-co-BYMA) (hPGVB) is designed and prepared successfully via a facile “bottom-up” strategy. The acetylated hPGVB is prepared by one-pot reversible addition-fragmentation chain transfer (RAFT) copolymerization of acrylate-type galactose monomers AcGalEA and methacrylate-type fluorescent monomers BYMA in presence of an inimer-type RAFT chain transfer agent. After deacetylation, the resulting amphiphilic hPGVB can self-assemble into stable nanoparticles in aqueous media, showing strong green fluorescence with relative high quantum yields and good photostability. The cell viability study indicates the excellent biocompatibility of the hPGVB fluorescent nanoparticles (FNPs) against HepG2 and NIH3T3 cells. More importantly, comparing with the galactose-free fluorescent hyperbranched polymers h-P(OEGMA-co-VBPT-co-BYMA), hPEVB FNPs can be selectively internalized by asialoglycoprotein (ASGP) receptor-rich HepG2 cells, indicating their potential application in the bioimaging fields. In the experiment, the researchers used many compounds, for example, (2S,3R,4S,5S,6R)-6-(Acetoxymethyl)tetrahydro-2H-pyran-2,3,4,5-tetrayl tetraacetate (cas: 4163-60-4Reference of 4163-60-4).

(2S,3R,4S,5S,6R)-6-(Acetoxymethyl)tetrahydro-2H-pyran-2,3,4,5-tetrayl tetraacetate (cas: 4163-60-4) 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 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 4163-60-4

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

DBU-assisted cyclorelease elimination: Combinatorial synthesis and 绾?glutamyl cysteine synthetase and glutathione-S-transferase modulatory effect of C-nucleoside analogs was written by Mishra, R. C.;Tewari, Neetu;Arora, Kavita;Ahmad, Rumana;Tripathi, R. P.;Tiwari, V. K.;Walter, R. D.;Srivastava, A. K.. And the article was included in Combinatorial Chemistry and High Throughput Screening in 2003.Quality Control of 3-Cyanophenylisocyanate This article mentions the following:

A combinatorial library of 60 C- nucleoside analogs was synthesized by sequential coupling of building blocks followed by cyclative cleavage with DBU in an efficient manner. Only DMSO soluble compounds were tested for their modulatory effect against filarial 绾?glutamyl cysteine synthetase (绾?GCase) and glutathione-S-transferases (GSTs). Several compounds were found to be weak inhibitors of filarial 绾?GCase, whereas, most of them stimulated filarial GSTs. In the experiment, the researchers used many compounds, for example, 3-Cyanophenylisocyanate (cas: 16413-26-6Quality Control of 3-Cyanophenylisocyanate).

3-Cyanophenylisocyanate (cas: 16413-26-6) belongs to esters. Esters typically have a pleasant smell; those of low molecular weight are commonly used as fragrances and are found in essential oils and pheromones. 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.Quality Control of 3-Cyanophenylisocyanate

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

High density polyethylene/wood flour composite: optimization of processing temperature, processing time and coupling agent concentration was written by Ranjbarha, Zahra;Aberoomand-Azar, Parviz;Mokhtari-Aliabad, Javad;Mirmohammadi, Seyed Amin;Saber-Tehrani, Mohammad. And the article was included in Polymers and Polymer Composites in 2021.Application of 6683-19-8 This article mentions the following:

Wood plastic composites (WPCs) consisting of high d. polyethylene (HDPE) reinforced with high-loading (55 wt%) of wood flour (WF) were fabricated with melt-blending technique. In this compounding method, processing parameters such as different mixing temperatures (of 165, 180 and 195鎺?, mixing times (of 5, 10 and 15 min) and coupling agent contents (of 2 and 4 wt%) were evaluated. Prepared specimens were analyzed with tensile, Izod, shore D, DMTA, short-term creep, DSC, TGA, water absorption and water contact angle characterizations. Results revealed that mixing temperature of 180鎺矯, mixing time of 10 min and coupling agent concentration of 4 wt% were found as the best processing conditions. The mentioned conditions provided enhanced dispersion of WF particles within the HDPE matrix, due to optimum viscosity of the polymer melt and effective residence time of compound in the mixer, and beside them efficient interfacial adhesion between WF and polymer matrix. In the experiment, the researchers used many compounds, for example, 2,2-Bis(((3-(3,5-di-tert-butyl-4-hydroxyphenyl)propanoyl)oxy)methyl)propane-1,3-diyl bis(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propanoate) (cas: 6683-19-8Application of 6683-19-8).

2,2-Bis(((3-(3,5-di-tert-butyl-4-hydroxyphenyl)propanoyl)oxy)methyl)propane-1,3-diyl bis(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propanoate) (cas: 6683-19-8) belongs to esters. Esters are widespread in nature and are widely used in industry. In nature, fats are in general triesters derived from glycerol and fatty acids. Esters are responsible for the aroma of many fruits, including apples, durians, pears, bananas, pineapples, and strawberries. Esters are more polar than ethers but less polar than alcohols. They participate in hydrogen bonds as hydrogen-bond acceptors, but cannot act as hydrogen-bond donors, unlike their parent alcohols. This ability to participate in hydrogen bonding confers some water-solubility.Application of 6683-19-8

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

Chemical Characterization of Five Tunisian Eucalyptus Essential Oils Species was written by Elaissi, Ameur;Moumni, Sarra;Roeleveld, Kevin;Larbi Khouja, Mohamed. And the article was included in Chemistry & Biodiversity in 2020.SDS of cas: 659-70-1 This article mentions the following:

Hydrodistillation of the dried leaves of five Eucalyptus species, E. alba REINW. ex BLUME, E. citriodora HOOK., E. paniculata SM., harvested from Choucha arboreta (region of Sejnane, northwest of Tunisia), E. pimpiniana MAIDEN from Mjez Elbab arboreta (north east of Tunisia) and E. bicolor A.CUNN ex HOOK from Sidi Smail arboreta (center of Tunisia), in March 2017, afforded essential oils in yields varying from 1.3鍗?.2 to 6.0鍗?.9% according to the species. E. citriodora provided the highest mean percentage of essential oil amongst all the species. Anal. by GC (RI) and GC/MS allowed the identification of 138 components representing 84.6-98.7% of the total oil. The content of the different samples varied according to the species. The main components were citronellol, followed by 1,8-cineole, 浼?pinene, 锜?cadinol, 7-epi-浼?eudesmol, trans-pinocarveol, spathulenol, aromadendrene, 绾?cadinene and 鏈?cadinene. The principal components and the hierarchical cluster analyses separated the five leaf essential oils into three groups, each group constituted a chemotype. In the experiment, the researchers used many compounds, for example, Isopentyl 3-methylbutanoate (cas: 659-70-1SDS of cas: 659-70-1).

Isopentyl 3-methylbutanoate (cas: 659-70-1) 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.SDS of cas: 659-70-1

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