Month: November 2022

Chakraborty, Amit published the artcileChemoselective disulfide formation by thiol-disulfide interchange in SIT-protected cysteinyl peptides, Quality Control of 71989-31-6, the publication is Journal of Organic Chemistry (2022), 87(1), 708-712, database is CAplus and MEDLINE.

Chemoselective disulfide formation is accomplished through a thiol-disulfide interchange approach using sec-isoamyl mercaptan (SIT) as an alkyl sulfenyl-protecting group of one of the Cys residues involved in the pairing. SIT has a dual and unique characteristic, acting as a masking group during the synthesis and directing disulfide formation in the presence of a free thiol. This novel approach is illustrated by the synthesis of several peptides of biol. interest.

Journal of Organic Chemistry published new progress about 71989-31-6. 71989-31-6 belongs to catalysis-chemistry, auxiliary class Amino acide derivatives,pyrrolidine, name is Fmoc-Pro-OH, and the molecular formula is C20H19NO4, Quality Control of 71989-31-6.

Referemce:
https://courses.lumenlearning.com/boundless-chemistry/chapter/catalysis/,
Catalysis – Wikipedia

Voronkov, M. G. published the artcileReaction of phenyltrifluorosilane and phenyl(hydrocarbyl)difluorosilanes with bis(2-hydroxyethyl)-and tris(2-hydroxyethyl)amine and their N-methyl and O-trimethylsilyl derivatives. A novel route to quasisilatranes, Application In Synthesis of 312-40-3, the publication is Russian Journal of General Chemistry (2006), 76(12), 1854-1859, database is CAplus.

Reaction of phenyltrifluorosilane, diphenyldifluorosilane, and methylphenyldifluorosilane with bis(2-hydroxyethyl)amine, Me-bis(2-hydroxyethyl)amine, Me-bis(2-trimethylsiloxyethyl)amine, leads to 1,3-dioxa-6-aza-2-silacyclooctane derivatives, (N→Si) quasisilatranes: 1,1-difluoroquasisilatrane, 1-phenyl-1-fluoro-5-methylquasisilatrane, or 1-methyl-1-fluoroquasisilatrane, containing the donor-acceptor bond N→Si and pentacoordinate Si atom. 1-Phenylsilatrane is the product of the reaction of phenyltrifluorosilane with tris(2-trimethylsiloxyethyl)amine, whereas with tris(2-hydroxyethyl)amine 1-phenylsilatrane and 1-fluorosilatrane were formed in the molar ratio of 3:1. The structure of the synthesized compounds was proved by ¹H, ¹³C, ¹⁵N, ¹⁹F, ²⁹Si NMR and IR spectroscopy.

Russian Journal of General Chemistry published new progress about 312-40-3. 312-40-3 belongs to catalysis-chemistry, auxiliary class Organic Silicones, name is Difluorodiphenylsilane, and the molecular formula is C20H19NO4, Application In Synthesis of 312-40-3.

Referemce:
https://courses.lumenlearning.com/boundless-chemistry/chapter/catalysis/,
Catalysis – Wikipedia

Rizzo, Giorgio published the artcileSilk-Fibroin-Supported Palladium Catalyst for Suzuki-Miyaura and Ullmann Coupling Reactions of Aryl Chlorides, Related Products of catalysis-chemistry, the publication is European Journal of Organic Chemistry (2022), 2022(16), e202101567, database is CAplus.

Pd/SF was tested as a catalyst for the Suzuki-Miyaura and Ullmann coupling reactions of aryl chlorides, in H₂O/EtOH solvent mixture under atm. conditions. Starting from the anal. of the products of the Pd/SF promoted Ullmann reactions of poly-haloarenes, the existence of catalytic pockets where monoat. palladium species could form stable complexes with SF. To shed light on this hypothesis, Pd/SF was characterized by Wide-Angle X-ray Scattering (WAXS) anal., which supported the supposition of catalytic pockets. Finally, using a computational model developed by Mol. Mechanic Energy Minimization was estimated the dimension of the catalytic pocket of Pd/SF (about 15 S), in good agreement with the exptl. results.

European Journal of Organic Chemistry published new progress about 613-33-2. 613-33-2 belongs to catalysis-chemistry, auxiliary class Benzene, name is 4,4′-Dimethyldiphenyl, and the molecular formula is C14H14, Related Products of catalysis-chemistry.

Referemce:
https://courses.lumenlearning.com/boundless-chemistry/chapter/catalysis/,
Catalysis – Wikipedia

Pourhajibagher, Maryam published the artcileQuorum quenching of Streptococcus mutans via the nano-quercetin-based antimicrobial photodynamic therapy as a potential target for cariogenic biofilm, Formula: C5H11NO2S, the publication is BMC Microbiology (2022), 22(1), 125, database is CAplus and MEDLINE.

Quorum sensing (QS) system can regulate the expression of virulence factors and biofilm formation in Streptococcus mutans. Antimicrobial photodynamic therapy (aPDT) inhibits quorum quenching (QQ), and can be used to prevent microbial biofilm. We thereby aimed to evaluate the anti-biofilm potency and anti-metabolic activity of nano-quercetin (N-QCT)-mediated aPDT against S. mutans. Also, in silico evaluation of the inhibitory effect of N-QCT on the competence-stimulating peptide (CSP) of S. mutans was performed to elucidate the impact of aPDT on various QS-regulated genes. Cytotoxicity and intracellular reactive oxygen species (ROS) generation were assessed following synthesis and confirmation of N-QCT. Subsequently, the min. biofilm inhibitory concentration (MBIC) of N-QCT against S. mutans and anti-biofilm effects of aPDT were assessed using colorimetric assay and plate counting. Mol. modeling and docking anal. were performed to confirm the connection of QCT to CSP. The metabolic activity of S. mutans and the expression level of various genes involved in QS were evaluated by flow cytometry and reverse transcription quant. real-time PCR, resp. Successful synthesis of non-toxic N-QCT was confirmed through several characterization tests. The MBIC value of N-QCT against S. mutans was 128μg/mL. Similar to the crystal violet staining, the results log10 CFU/mL showed a significant degradation of preformed biofilms in the group treated with aPDT compared to the control group (P < 0.05). Following aPDT, metabolic activity of S. mutans also decreased by 85.7% (1/2 x MBIC of N-QCT) and 77.3% (1/4 x MBIC of N-QCT), as compared to the control values (P < 0.05). In silico anal. showed that the QCT mol. was located in the site formed by polypeptide helixes of CSP. The relative expression levels of the virulence genes were significantly decreased in the presence of N-QCT-mediated aPDT (P < 0.05). The combination of N-QCT with blue laser as a QQ-strategy leads to maximum ROS generation, disrupts the microbial biofilm of S. mutans, reduces metabolic activity, and downregulates the expression of genes involved in the QS pathway by targeting genes of the QS signaling system of S. mutans.

BMC Microbiology published new progress about 63-68-3. 63-68-3 belongs to catalysis-chemistry, auxiliary class Natural product, name is (S)-2-Amino-4-(methylthio)butanoic acid, and the molecular formula is C5H11NO2S, Formula: C5H11NO2S.

Referemce:
https://courses.lumenlearning.com/boundless-chemistry/chapter/catalysis/,
Catalysis – Wikipedia

Danil de Namor, A. F. published the artcileAmine-modified silica for removing aspirin from water, Recommanded Product: 3-(Trimethoxysilyl)propan-1-amine, the publication is International Journal of Environmental Science and Technology (2022), 19(5), 4143-4152, database is CAplus.

Abstract: The synthesis and structural characterization (Fourier transform IR, FTIR spectrometry, SEM, SEM and energy-dispersive X-ray, EDX) of amino-modified silicates (unloaded L1, and aspirin-loaded, L2) are reported. The optimal conditions for the extraction of aspirin from water by the modified silicate material were determined as a function of the mass of the extracting agent and the pH of the aqueous solution The optimum mass was found to be 0.08-0.10 g with 99.9% removal of aspirin. Maximum extraction of aspirin by the material was observed at pH 4. The kinetics, the removal capacity of the material, as well as its recycling, were investigated. The results indicate that (i) the process is fast and (ii) the removal capacity for the drug is greater than that of previously reported materials and (iii)the modified silicate can be easily recycled. These data along with the low cost involved in the production of the material led to the conclusion that the modified silicate has the required potential for industrial use. Mol. simulation calculations suggest that one unit of aspirin interacts with one unit of the modified silicate L1 through hydrogen bond formation between the amine functional group of the silicate and the oxygen donor atoms of aspirin. Final conclusions are given.

International Journal of Environmental Science and Technology published new progress about 13822-56-5. 13822-56-5 belongs to catalysis-chemistry, auxiliary class Organic Silicones, name is 3-(Trimethoxysilyl)propan-1-amine, and the molecular formula is C6H17NO3Si, Recommanded Product: 3-(Trimethoxysilyl)propan-1-amine.

Referemce:
https://courses.lumenlearning.com/boundless-chemistry/chapter/catalysis/,
Catalysis – Wikipedia

Quispe, Renato published the artcileControversies in the Use of Omega-3 Fatty Acids to Prevent Atherosclerosis, Related Products of catalysis-chemistry, the publication is Current Atherosclerosis Reports (2022), 24(7), 571-581, database is CAplus and MEDLINE.

A review. Abstract: Purpose of Review: We discuss current controversies in the clin. use of omega-3 fatty acids (FA), primarily eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), and examine discrepancies between recent trials. Furthermore, we discuss potential side effects reported in these studies and the role of mixed omega-3 FA dietary supplements and concerns about their use. Recent Findings: REDUCE-IT showed that addition of icosapent Et, a highly purified form of EPA, can reduce risk of cardiovascular events among statin-treated individuals with high triglycerides. Addnl. supportive evidence for EPA has come from other trials and meta-analyses of omega-3 FA therapy. In contrast, trials of mixed EPA/DHA products have consistently failed to improve cardiovascular outcomes. Discrepancies in results reported in RCTs could be explained by differences in omega-3 FA products, dosing, study populations, and study designs including the placebo control formulation. Evidence obtained from highly purified forms should not be extrapolated to other mixed formulations, including “over-the-counter” omega-3 supplements. Summary: Targeting TG-rich lipoproteins represents a new frontier for mitigating ASCVD risk. Clin. and basic research evidence suggests that the use of omega-3 FA, specifically EPA, appears to slow atherosclerosis by reducing triglyceride-rich lipoproteins and/or inflammation, therefore addressing residual risk of clin. ASCVD.

Current Atherosclerosis Reports published new progress about 6217-54-5. 6217-54-5 belongs to catalysis-chemistry, auxiliary class Alkenyl,Carboxylic acid,Aliphatic hydrocarbon chain,Metabolic Enzyme,RAR/RXR,Natural product, name is Docosahexaenoic Acid, and the molecular formula is C22H32O2, Related Products of catalysis-chemistry.

Referemce:
https://courses.lumenlearning.com/boundless-chemistry/chapter/catalysis/,
Catalysis – Wikipedia

Inkster, J. A. H. published the artcileA non-anhydrous, minimally basic protocol for the simplification of nucleophilic ¹⁸F-fluorination chemistry, Safety of Tetraethylammonium hydrogencarbonate, the publication is Scientific Reports (2020), 10(1), 6818, database is CAplus and MEDLINE.

Abstract: Fluorine-18 radiolabeling typically includes several conserved steps including elution of the [¹⁸F]fluoride from an anion exchange cartridge with a basic solution of K₂CO₃ or KHCO₃ and Kryptofix 2.2.2. in mixture of acetonitrile and water followed by rigorous azeotropic drying to remove the water. In this work we describe an alternative “non-anhydrous, minimally basic” (“NAMB”) technique that simplifies the process and avoids the basic conditions that can sometimes limit the scope and efficiency of [¹⁸F]fluoride incorporation chem. In this approach, [¹⁸F]F^– is eluted from small (10-12 mg) anion-exchange cartridges with solutions of tetraethylammonium bicarbonate, perchlorate or tosylate in polar aprotic solvents containing 10-50% water. After dilution with addnl. aprotic solvent, these solutions are used directly in nucleophilic aromatic and aliphatic ¹⁸F-fluorination reactions, obviating the need for azeotropic drying. Perchlorate and tosylate are minimally basic anions that are nevertheless suitable for removal of [¹⁸F]F^– from the anion-exchange cartridge. As proof-of-principle, “NAMB” chem. was utilized for the synthesis of the dopamine D₂/D₃ antagonist [¹⁸F]fallypride.

Scientific Reports published new progress about 17351-61-0. 17351-61-0 belongs to catalysis-chemistry, auxiliary class Phase Transfer Catalyst, name is Tetraethylammonium hydrogencarbonate, and the molecular formula is C9H21NO3, Safety of Tetraethylammonium hydrogencarbonate.

Referemce:
https://courses.lumenlearning.com/boundless-chemistry/chapter/catalysis/,
Catalysis – Wikipedia

Moore, Thomas M. published the artcileEffect of leaving group substituents on the microfluidic synthesis of [¹⁸F]3-fluoro-5-[(pyridin-3-yl)ethynyl]benzonitrile ([¹⁸F]FPEB), Safety of Tetraethylammonium hydrogencarbonate, the publication is Heterocycles (2017), 95(2), 807-815, database is CAplus.

A com. microfluidic reactor system was used to synthesize the mGLUR₅ receptor imaging agent [¹⁸F]FPEB. To study the effect of leaving group substituents on the synthesis of the desired compound, the chloro-, bromo-, iodo- and nitro-substituted precursors for FPEB were evaluated. Precursor concentrations of 4-10 mg/mL were evaluated in various solvents, with temperature ranges between 120 and 220° and total processing times of less than five minutes. Optimized incorporation yields ranged from 5% to 69.4% depending on the precursor used.

Heterocycles published new progress about 17351-61-0. 17351-61-0 belongs to catalysis-chemistry, auxiliary class Phase Transfer Catalyst, name is Tetraethylammonium hydrogencarbonate, and the molecular formula is C9H21NO3, Safety of Tetraethylammonium hydrogencarbonate.

Referemce:
https://courses.lumenlearning.com/boundless-chemistry/chapter/catalysis/,
Catalysis – Wikipedia

Yamaguchi, Shigehiro published the artcileSynthesis, Structures, Photophysical Properties, and Dynamic Stereochemistry of Tri-9-anthrylsilane Derivatives, Product Details of C12H10F2Si, the publication is Organometallics (1998), 17(20), 4347-4352, database is CAplus.

Tri-9-anthrylsilanes having various substituents, such as -F, -H, -OH, -OMe, vinyl, and ethynyl, were prepared, and their UV-visible absorption and fluorescence spectra were determined Chiral propeller-like arrangements of three anthryl groups were confirmed by x-ray structural anal. of the fluoro and vinyl derivatives In solution, however, all the trianthrylsilanes prepared herein undergo enantiomerization at room temperature The free energies of enantiomerization are âˆ?-10 kcal mol^-1, determined by variable-temperature ¹H NMR. The propeller-like structure significantly reduces the quantum yield of fluorescence of the anthracene chromophore.

Organometallics published new progress about 312-40-3. 312-40-3 belongs to catalysis-chemistry, auxiliary class Organic Silicones, name is Difluorodiphenylsilane, and the molecular formula is C19H34ClN, Product Details of C12H10F2Si.

Referemce:
https://courses.lumenlearning.com/boundless-chemistry/chapter/catalysis/,
Catalysis – Wikipedia

Yamaguchi, Shigehiro published the artcileEffect of Countercation Inclusion by [2.2.2]Cryptand upon Stabilization of Potassium Organofluorosilicates, Name: Difluorodiphenylsilane, the publication is Organometallics (1999), 18(15), 2851-2854, database is CAplus.

The reaction of organofluorosilanes with KF in the presence of [2.2.2]cryptand affords the corresponding organofluorosilicates with K⁺/[2.2.2]cryptand as the countercation. Not only diorganotrifluorosilicates, Ph₂SiF₃^–, but also triorganodifluorosilicates, Ph₃SiF₂^– and Ph₂MeSiF₂^–, were obtained as stable solids. The x-ray crystal structure analyses of these silicates show that three-dimensional inclusion of the K cation by cryptand prevents an interaction between the K atom and F atoms of the silicates. A comparison of the countercation between K⁺/[2.2.2]cryptand and K⁺/18-crown-6 reveals that the inclusion of the K cation by cryptand subtly facilitates the intramol. ligand exchange, as observed by the variable-temperature ¹⁹F NMR spectra.

Organometallics published new progress about 312-40-3. 312-40-3 belongs to catalysis-chemistry, auxiliary class Organic Silicones, name is Difluorodiphenylsilane, and the molecular formula is C19H34ClN, Name: Difluorodiphenylsilane.

Referemce:
https://courses.lumenlearning.com/boundless-chemistry/chapter/catalysis/,
Catalysis – Wikipedia