Month: November 2022

Ahonen, Eija published the artcileOxidative stability, oxidation pattern and alpha-tocopherol response of docosahexaenoic acid (DHA, 22:6n-3)-containing triacylglycerols and ethyl esters, Synthetic Route of 6217-54-5, the publication is Food Chemistry (2022), 132882, database is CAplus and MEDLINE.

DHA is most often used in supplements either in its triacylglycerol or Et ester form. Currently, there is only little published data on the differences in the oxidative stability and ¦Á-tocopherol response between the two lipid structures, as well as on the oxidation patterns of pure DHA. This study investigated the oxidative stability, ¦Á-tocopherol response and oxidation pattern of DHA incorporated in triacylglycerols and as Et esters with an untargeted approach after oxidation at 50 ¡ãC in the dark. Liquid and gas chromatog. methods with mass spectrometric detection and NMR spectroscopy were applied. DHA was more stable in triacylglycerols than as Et esters without ¦Á-tocopherol addition With ¦Á-tocopherol added the opposite was observed The oxidation products formed during triacylglycerol and Et ester oil oxidation were mostly similar, but also some structure-related differences were detected in both volatile and non-volatile oxidation products.

Food Chemistry 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, Synthetic Route of 6217-54-5.

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

Zlatkovic, Dragan published the artcileA novel pathway for the thermolysis of N-nitrosoanthranilates using flash vacuum pyrolysis leading to 7-aminophthalides, SDS of cas: 119-80-2, the publication is Organic & Biomolecular Chemistry (2020), 18(41), 8371-8375, database is CAplus and MEDLINE.

Flash vacuum pyrolysis of Me N-methyl-N-nitrosoanthranilate leads to elimination of nitric oxide and disproportionation of the formed N-radical to 7-(methylamino)phthalide and Me N-methylanthranilate. This transformation is a convenient, solvent-free method for the preparation of 7-(methylamino)phthalides. An alternative route through pyrolysis of N-benzyl-N-Me anthranilates was also studied.

Organic & Biomolecular Chemistry published new progress about 119-80-2. 119-80-2 belongs to catalysis-chemistry, auxiliary class sulfides,Carboxylic acid,Benzene, name is 2,2′-Dithiodibenzoic acid, and the molecular formula is C8H14O4, SDS of cas: 119-80-2.

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

Nakagawa, Takeshi published the artcilePiezochromic luminescence of dicoronylene: Key for revealing hidden Raman modes at high pressure, HPLC of Formula: 191-07-1, the publication is Carbon (2022), 563-569, database is CAplus.

Mol. crystals of dicoronylene (C₄₈H₂₀), a member of very large polycyclic aromatic hydrocarbons (PAHs), exhibits strong red fluorescence under ambient conditions. This strong fluorescence induced by visible light excitation obscures entire Raman spectrum of dicoronylene. The authors employed in-situ high-pressure luminescence spectroscopy to observe a reversible piezochromic effect, in which the fluorescence exhibits a drastic red shift with a rapid quenching of intensity. At >4 GPa, under red shifted and reduced fluorescence, hidden Raman modes are observed with 532 nm green laser at ¡Ü20 GPa. The application of pressure can finely tune the fluorescence of dicoronylene, allowing the observation of the Raman spectrum with an appropriate laser wavelength and dicoronylene has high chem. stability among PAH mols. with multiple aromatic rings.

Carbon published new progress about 191-07-1. 191-07-1 belongs to catalysis-chemistry, auxiliary class Electronic Materials, name is Coronene, and the molecular formula is C24H12, HPLC of Formula: 191-07-1.

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

Hofmann, Andreas published the artcileCyclometalated Analogues of Platinum Terpyridine Complexes: Kinetic Study of the Strong ¦Ò-Donor Cis and Trans Effects of Carbon in the Presence of a ¦Ð-Acceptor Ligand Backbone, Recommanded Product: 1,1-Dimethylthiourea, the publication is Inorganic Chemistry (2003), 42(20), 6528-6538, database is CAplus and MEDLINE.

The substitution kinetics of the complexes [Pt(N-N-C)Cl] (N-N-CH = 6-phenyl-2,2′-bipyridine), [Pt(N-C-N)Cl] (N-CH-N = 1,3-di(2-pyridyl)benzene), and [Pt(N-N-N)Cl]Cl (N-N-N = 2,2′:6′,2”-terpyridine) with the nucleophiles Br^–, I^–, and, for the first two complexes, also thiourea, N,N-dimethylthiourea, and N,N,N’,N’-tetramethylthiourea, have been studied in methanol as solvent. In case of the thioureas, the activation parameters ¦¤H^?, ¦¤S^?, and ¦¤V^? were also determined from the temperature and pressure dependence of the reactions. Two crystal structures of [Pt(N-N-C)Cl] were determined (yellow and red polymorphs); the intense red color of the latter polymorph results from Pt-Pt interactions (Pt-Pt distance = 3.366 ?). The data enable an anal. of the cis and trans effects and the influence of the strong ¦Ò-donor carbon in the presence of an electron withdrawing ¦Ð-acceptor ligand backbone. The results indicate that the intrinsic reactivity is enhanced greatly by the labilizing effect of the trans carbon donor, but the nucleophilic discrimination is dramatically reduced due to the decrease in electrophilicity on the metal center. However, although the electron withdrawing ¦Ð-acceptor effect is partly counteracted by the ¦Ò-donor effect, the complex still benefits from a higher nucleophilic discrimination than in the comparable Pt(II) trans carbon donor complexes, where no or fewer ¦Ð-acceptors are present. In the case of the cis carbon donor complex, the intrinsic reactivity remains unchanged, but the nucleophilic discrimination is reduced and leads to a reduced reactivity of the [Pt(N-N-C)Cl] complex in comparison to [Pt(N-N-N)Cl]Cl. On the basis of these results, a more detailed treatment of the nature of the cis effect is offered.

Inorganic Chemistry published new progress about 6972-05-0. 6972-05-0 belongs to catalysis-chemistry, auxiliary class Thiourea,Amine,Aliphatic hydrocarbon chain,Amide, name is 1,1-Dimethylthiourea, and the molecular formula is C3H8N2S, Recommanded Product: 1,1-Dimethylthiourea.

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

Belmokaddem, Fatima-Zohra published the artcileNovel nucleophilic/basic and acidic organocatalysts for reaction between poorly reactive diisocyanate and diols, Name: Dimesitylphosphine oxide, the publication is Designed Monomers and Polymers (2016), 19(4), 347-360, database is CAplus.

Original basic or acidic organic compounds derived from guanidine or Ph phosphonic acid were specifically designed and tested as new catalysts for the bulk synthesis of polyurethane prepolymers from a precursor system with particularly low reactivity (secondary alc. + aliphatic isocyanate at low temperature). Both families showed interesting catalytic activities at 60-80¡ã, but must nevertheless be used in much higher amounts (1 mol%, i.e. between 0.15 and 0.50 wt%) than traditional metal-based catalysts. The efficiency of guanidine derivatives seems to be related to their nucleophilicity, whereas that of phosphonic acid derivatives depends on their acidity. However, the solubility of the considered species in the reactive medium also plays a major role. The water/alc. selectivity of the catalysts, especially at room temperature, was then examined as an addnl. criterion. Guanidines are not selective and favor the reaction of isocyanate groups with water as much as that with alcs. Ph phosphonic acid derivatives are more selective, and particularly pentafluorophenyl phosphonic acid displays a remarkable catalytic activity together with an acceptable selectivity and could represent an interesting and safer alternative to toxic tin and mercury derivatives for many industrial polyurethanes.

Designed Monomers and Polymers published new progress about 23897-16-7. 23897-16-7 belongs to catalysis-chemistry, auxiliary class Aryl phosphine ligand,Mono-phosphine Ligands, name is Dimesitylphosphine oxide, and the molecular formula is C18H23OP, Name: Dimesitylphosphine oxide.

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

Ghirga, Francesca published the artcileUndecenyl resorc[4]arene in the chair conformation as preorganized synthon for olefin metathesis, Category: catalysis-chemistry, the publication is RSC Advances (2013), 3(38), 17567-17576, database is CAplus.

Tetramerization of (E)-2,4-dimethoxycinnamic acid ¦Ø-undecenyl ester with ethereal BF₃ gave three stereoisomers 1a, 1b, and 1c, which were assigned as the chair, cone, and 1,2-alternate conformations, resp. The chair conformation of 1a was confirmed by X-ray diffraction anal., which also showed a peculiar self-assembly behavior in the crystal lattice, forming intercalated hydrophilic and hydrophobic layers (6-7 ? thickness) as a consequence of strong CH-¦Ð interactions. Undecenyl resorc[4]arene 1a, which featured the simplest pattern of substituents, was submitted to olefin metathesis using the second-generation Grubbs complex as the catalyst. Depending on the reaction conditions, different products were isolated: a bicyclic alkene 2a (46%), a linear dimer 3a (5%), and a cross-linked homopolymer P1a (44%).

RSC Advances published new progress about 16909-09-4. 16909-09-4 belongs to catalysis-chemistry, auxiliary class Alkenyl,Carboxylic acid,Benzene,Ether, name is (E)-3-(2,4-Dimethoxyphenyl)acrylic acid, and the molecular formula is C11H12O4, Category: catalysis-chemistry.

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

Santos, Joao Cesar N. published the artcileThimerosal changes protein conformation and increase the rate of fibrillation in physiological conditions: Spectroscopic studies using bovine serum albumin (BSA), SDS of cas: 119-80-2, the publication is International Journal of Biological Macromolecules (2018), 1032-1040, database is CAplus and MEDLINE.

The interaction between bovine serum albumin (BSA) and thimerosal (TM), an organomercury compound widely employed as a preservative in vaccines, was investigated simulating physiol. conditions and using different spectroscopic techniques. The results, employing mol. fluorescence showed the interaction occurs by static quenching through electrostatic forces (¦ÄH < 0 and ¦ÄS > 0), spontaneously (¦ÄG = -4.40 kJ mol^-1) and with a binding constant of 3.24 ¡Á 10³ M^-1. Three-dimensional fluorescence studies indicated that TM causes structural changes in the polypeptide chain of the BSA, confirmed by CD that showed an increase in a-helix (from 43.9 to 47.8%) content after interaction process. Through synchronized fluorescence and employing bilirubin as a protein site marker, it was confirmed the preferential interaction of TM in the subdomain IB of BSA. The interaction mechanism proposed in this work is based on the reaction of TM with BSA through of free Cys34 residue, forming the adduct BSA-HgEt with the thiosalicylic acid release, which possibly interacts electrostatically with pos. side chain amino acids of the modified protein. Finally, it was proven that both TM and EtHgCl accelerate the protein fibrillation kinetics in 42 and 122%, resp., indicating the toxicity of these compounds in biol. systems.

International Journal of Biological Macromolecules published new progress about 119-80-2. 119-80-2 belongs to catalysis-chemistry, auxiliary class sulfides,Carboxylic acid,Benzene, name is 2,2′-Dithiodibenzoic acid, and the molecular formula is C14H10O4S2, SDS of cas: 119-80-2.

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

dos Santos, Beatriz F. published the artcileAnchored Pd(0) Nanoparticles on Synthetic Talc for the Synthesis of Biaryls and a Precursor of Angiotensin II Inhibitors, Product Details of C14H14, the publication is Synthesis (2021), 53(5), 933-942, database is CAplus.

The palladium-catalyzed Suzuki-Miyaura cross-coupling reaction is one of the most important and efficient reactions to prepare a variety of organic compounds, including biaryls. Despite the overwhelming number of reports related to this topic, some methodol. difficulties persist in terms of catalyst handling, recovery, and reuse, as well as the reaction media. This work reports the rational design of new, efficient, cost-effective, and reusable palladium catalysts supported on synthetic talc for the Suzuki-Miyaura reaction. From the results, key points were identified: both designed catalysts accelerated the reaction in EtOH and an open-flask setup, affording moderate to excellent yields within a short time (e.g., 30 min) even for deactivated aryl halides; the protocol can be applied to a great number of both cross-coupling partners, showing an excellent functional group tolerance; the catalysts can be recovered and reused without significant loss of activity. This protocol was used for the synthesis of a precursor of angiotensin II inhibitors such as valsartan, losartan, irbesartan, and telmisartan.

Synthesis 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, Product Details of C14H14.

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

Raynal, Noel J.-M. published the artcileRepositioning FDA-Approved Drugs in Combination with Epigenetic Drugs to Reprogram Colon Cancer Epigenome, Application In Synthesis of 38260-01-4, the publication is Molecular Cancer Therapeutics (2017), 16(2), 397-407, database is CAplus and MEDLINE.

Epigenetic drugs, such as DNA methylation inhibitors (DNMTi) or histone deacetylase inhibitors (HDACi), are approved in monotherapy for cancer treatment. These drugs reprogram gene expression profiles, reactivate tumor suppressor genes (TSG) producing cancer cell differentiation and apoptosis. Epigenetic drugs have been shown to synergize with other epigenetic drugs or various anticancer drugs. To discover new mol. entities that enhance epigenetic therapy, we performed a high-throughput screening using FDA-approved libraries in combination with DNMTi or HDACi. As a screening model, we used YB5 system, a human colon cancer cell line, which contains an epigenetically silenced CMV-GFP locus, mimicking TSG silencing in cancer. CMV-GFP reactivation is triggered by DNMTi or HDACi and responds synergistically to DNMTi/HDACi combination, which phenocopies TSG reactivation upon epigenetic therapy. GFP fluorescence was used as a quant. readout for epigenetic activity. We discovered that 45 FDA-approved drugs (4% of all drugs tested) in our FDA-approved libraries enhanced DNMTi and HDACi activity, mainly belonging to anticancer and antiarrhythmic drug classes. Transcriptome anal. revealed that combination of decitabine (DNMTi) with the antiarrhythmic proscillaridin A produced profound gene expression reprogramming, which was associated with downregulation of 153 epigenetic regulators, including two known oncogenes in colon cancer (SYMD3 and KDM8). Also, we identified about 85 FDA-approved drugs that antagonized DNMTi and HDACi activity through cytotoxic mechanisms, suggesting detrimental drug interactions for patients undergoing epigenetic therapy. Overall, our drug screening identified new combinations of epigenetic and FDA-approved drugs, which can be rapidly implemented into clin. trials. Mol Cancer Ther; 16(2); 397-407. ?2016 AACR.

Molecular Cancer Therapeutics published new progress about 38260-01-4. 38260-01-4 belongs to catalysis-chemistry, auxiliary class Chelating Agents, name is N1,N1′-(Ethane-1,2-diyl)bis(ethane-1,2-diamine) dihydrochloride, and the molecular formula is C6H20Cl2N4, Application In Synthesis of 38260-01-4.

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

Vagner, Adrienn published the artcileA rigidified AAZTA-like ligand as efficient chelator for ⁶⁸Ga radiopharmaceuticals, Quality Control of 140-28-3, the publication is ChemistrySelect (2016), 1(2), 163-171, database is CAplus.

The new cyclohexane-fused CyAAZTA ligand was synthesized to increase the structural rigidity of the heptadentate chelator AAZTA with the aim of improving the overall stability of its Ga^III complex. The stability constant of Ga(CyAAZTA)^–, determined both by pH-potentiometry (logK_GaL=21.39) and by ⁷¹Ga NMR (logK_GaL=21.92), was found similar to that of GaAAZTA (logK_GaL=22.18). The kinetic inertness of Ga(CyAAZTA)^– was investigated by following its transmetallation and ligand exchange reactions with Cu²⁺ and human serum transferrin, resp. The formation of a hydroxido-complex near pH 7 decreases the half-life (t_1/2) of the dissociation reactions for Ga(CyAAZTA)^– compared to Ga(AAZTA)^– (8.5 h vs 21 h, pH 7.4). However, at pH < 7 the t_1/2 of Ga(CyAAZTA)^– is much longer (234 h at pH 6). Finally, CyAAZTA was successfully radiolabeled with ⁶⁸Ga in acetate buffer at pH 3.8, in 15 min at room temperature at [CyAAZTA]=10 ¦ÌM, with a labeling yield higher than 80 %. A 1 ¦ÌM solution of CyAAZTA was successfully labeled (L.Y.: 97.4 %) in 5 min at 90 ¡ãC. Stability tests in human serum and in the presence of 50 mM DTPA showed no significant decomposition of ⁶⁸GaCyAAZTA over 90 min.

ChemistrySelect published new progress about 140-28-3. 140-28-3 belongs to catalysis-chemistry, auxiliary class Benzenes, name is N1,N2-Dibenzylethane-1,2-diamine, and the molecular formula is C5H10N2OS, Quality Control of 140-28-3.

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