Tag: M.W=300-350

Elkhalifa, Mahmoud published the artcileSolid-phase photochemical decarboxylative hydroalkylation of peptides, Application of Fmoc-Pro-OH, the publication is Organic Letters (2021), 23(21), 8219-8223, database is CAplus and MEDLINE.

The compatibility of photochem. with solid-phase peptide synthesis is demonstrated via photochem. hydroalkylation to form C(sp³)-C(sp³) bonds between on-resin Giese acceptors and redox-active esters. Both iridium-based photocatalysts and Hantszch ester led to high yields, with final reaction conditions producing full conversions within 30 min under ambient conditions. The chem. is compatible with a broad range of peptide side chains, redox-active esters, and resin. These conditions represent the first example of photochem. peptide modifications on resin.

Organic Letters 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, Application of Fmoc-Pro-OH.

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

Elgengehi, Sara M. published the artcileAdsorption of chlorine oxyanions, as water disinfectant by-products, on graphene flakes: A quantum chemical investigation, Quality Control of 191-07-1, the publication is Surfaces and Interfaces (2022), 101601, database is CAplus.

Chlorine oxyanions namely: hypochlorite ClO^–, chlorite ClO^–₂, chlorate ClO^–₃, and perchlorate ClO^–₄, are considered to be harmful for public health since they are disinfectant byproducts and are usually found in the disinfection process of drinking water treatment plants (DWTPs). The removal of these oxyanions is, therefore, an important demand. In the current work, the adsorption of chlorine oxyanions on some graphene flakes (Gr) such as coronene (C₂₄H₁₂), circumcoronene (C₅H₁₈), and circumcircumcoronene (C₉₆H₂₄), has been theor. investigated. Favorable adequate (anion-¦Ð) interaction between the chlorine oxyanions and the electron-rich graphene flakes have been elucidated, where the stabilization largely originates from attractive electrostatic and dispersion effects. The exponential increase in the attractive electrostatic and dispersion components of the adsorption energies is found to be, in part, a consequence of a charge transfer contribution from the oxygen lone pairs of electrons of oxyanions (donors) to the low-lying ¦Ð*-orbitals of graphene flakes (acceptors). This finding means that the favorable anion-¦Ð interaction between a chlorine oxyanion and a graphene surface is not purely non-covalent.

Surfaces and Interfaces 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, Quality Control of 191-07-1.

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

Pascoe, Cameron A. published the artcileMethylene analogs of neopetrosiamide as potential antimetastatic agents: solid-supported syntheses using diamino diacids for pre-stapling of peptides with multiple disulfides, COA of Formula: C20H19NO4, the publication is Organic Letters (2021), 23(23), 9216-9220, database is CAplus and MEDLINE.

Neopetrosiamide, a 28-residue peptide from Neopetrosia sp., contains three disulfide bonds and hinders mammalian tumor cell invasion. Proper connectivity of disulfide bonds is crucial for activity. Synthetic replacement of single disulfide bridges with methylene bridges gives active analogs. Pre-stapling of one ring enhances the correct formation of the remaining disulfides by reducing isomeric possibilities and possibly initiating the correct 3D fold. Cloning and expression of neopetrosiamide in E. coli affords access to the natural linear peptide.

Organic Letters 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, COA of Formula: C20H19NO4.

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

Marasini, Nirmal published the artcileDevelopment of a hyperbranched polymer-based methotrexate nanomedicine for rheumatoid arthritis, Application of Fmoc-Pro-OH, the publication is Acta Biomaterialia (2022), 298-307, database is CAplus and MEDLINE.

Methotrexate (MTX) is an effective disease modifying anti-rheumatic drug, but can cause significant hepatotoxicity and liver failure in some individuals. The goal of this work was to develop a MTX-conjugated hyperbranched polymeric nanoparticle based on oligo(ethylene glycol) Me ether methacrylate (OEGMA) and examine its ability to selectively deliver MTX to rheumatic joints while sparing the liver. MTX was conjugated to the hyperbranched polymer via a matrix metalloproteinase-13 cleavable peptide linker. Two populations of nanoparticles were produced, with sizes averaging 20 and 200nm. Tri-peptide (FFK)-modified MTX was liberated in the presence of matrix metalloproteinase 13 (MMP-13)and showed 100 to 1000-fold lower antiproliferative capacity in monocytic THP-1 cells compared to unmodified MTX, depending on whether the gamma-carboxylate of MTX was functionalized with O-tert-Bu. Nanoparticles showed prolonged plasma exposure after i.v. injection with a terminal half-life of approx. 1 day, but incomplete (50%) absorption after s.c. administration. Nanoparticles selectively accumulated in inflamed joints in a rat model of rheumatoid arthritis and showed less than 5% biodistribution in the liver after 5 days. MTX-OtBu nanoparticles also showed no hepatocellular toxicity at 500 ¦ÌM MTX equivalent This work provides support for the further development of OEGMA-based hyperbranched polymers as MTX drug delivery systems for rheumatoid arthritis. Nanomedicines containing covalently conjugated methotrexate offer the potential for selective accumulation of the potent hepatotoxic drug in rheumatic joints and limited liver exposure. One limitation of the high surface presentation of methotrexate on a nanoparticle surface, however, is the potential for enhanced liver uptake. We developed several OEGMA-based hyperbranched polymers containing alpha-carboxyl modified and unmodified methotrexate conjugated via an MMP-13 cleavable hexapeptide linker. The modified methotrexate polymer showed promising in vitro and in vivo behavior warranting further development and optimization as an anti-rheumatic nanomedicine. This work presents a new avenue for further research into the development of hyperbranched polymers for rheumatoid arthritis and suggests interesting approaches that may overcome some limitations associated with the translation of anti-rheumatic nanomedicines into patients.

Acta Biomaterialia 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, Application of Fmoc-Pro-OH.

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

Fonseca, Vanessa F. published the artcileFatty acid-based index development in estuarine organisms to pinpoint environmental contamination, Recommanded Product: Docosahexaenoic Acid, the publication is Marine Pollution Bulletin (2022), 113805, database is CAplus and MEDLINE.

Estuaries have long been preferred areas of human settlement, where multiple anthropogenic activities take place, which have contributed to a significant decrease in environmental quality of these ecosystems. Accordingly, environmental monitoring and management have long relied on the development of tools that summarize and simplify complex information and provide direct interpretation of quality status. Here, the fatty acid profiles of three abundant estuarine species, namely Hediste diversicolor, Carcinus maenas and Pomatoschistus microps, were used to develop and validate a multimetric index, based on the Euclidean dissimilarities of profiles between sites, in response to contamination gradient in a large urban estuary. Spatial differences were generally related to unsaturated fatty acids (mono- and polyunsaturated, of the n-3 and n-6 series) in all species, albeit more pronounced in P. microps. Multivariate models returned high classification accuracies for the three sampled sites, varying from 73.3% in the invertebrate species to 100.0% in the fish species. Results show the applicability of the developed FA-based index, particularly due to the easy of communication, for managers and the public alike, but also highlight the need for prior validation on species suitability or sensitivity to depict environmental contamination.

Marine Pollution Bulletin 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, Recommanded Product: Docosahexaenoic Acid.

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

Stokes, E. D. published the artcileHigh efficiency dye laser tunable from the UV to the IR, Application of 5,9-Diaminobenzo[a]phenoxazin-7-ium acetate, the publication is Optics Communications (1972), 5(4), 267-70, database is CAplus.

A dye laser was developed as a source of tunable radiation at 3500-7300 ?. A variety of dyes and dye mixtures were used to cover this range. Output powers ¡Ü30 kW were obtained with line widths <1.8 ?. A Fabry-Perot etalon reduced the output line width of 0.1 ? and the peak output power by a factor of 3. Second harmonic powers in excess of 2 kW were generated from the output of this laser. The efficient 2nd harmonic generation extended the lower wavelength limit to 2442 A. A N laser was used as pumping source.

Optics Communications published new progress about 10510-54-0. 10510-54-0 belongs to catalysis-chemistry, auxiliary class Other Aromatic Heterocyclic,Salt,Amine,Inhibitor,Inhibitor, name is 5,9-Diaminobenzo[a]phenoxazin-7-ium acetate, and the molecular formula is C8H7NO4, Application of 5,9-Diaminobenzo[a]phenoxazin-7-ium acetate.

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

Bose, Purnandhu published the artcileCombined Solution-Phase, Solid-Phase and Phase-Interface Anion Binding and Extraction Studies by a Simple Tripodal Thiourea Receptor, Application of Tetrabutylammonium hydrogencarbonate, the publication is European Journal of Inorganic Chemistry (2012), 2012(35), 5791-5801, database is CAplus.

Tris(2-aminoethyl)amine (tren) based 4-cyanophenyl-substituted tripodal L, tris{[(4-cyanophenyl)amino]ethyl}thiourea receptor, was synthesized and explored thoroughly for anion recognition in solution by NMR spectroscopy and isothermal titration calorimetry (ITC) as well as in the solid state by single-crystal X-ray diffraction studies. Anion recognition properties of L were further exploited toward the extraction of sulfate as well as fluoride from aqueous media using a liquid-liquid extraction technique. A solution-state anion binding study using NMR spectroscopy in [D₆]DMSO and ITC measurements in dry acetonitrile show a relatively higher association constant of L with halides (F^– and Cl^–) over oxyanions (H₂PO₄^– and HSO₄^–). The single-crystal X-ray structural anal. of complex 1 reveals a monotopic encapsulation of fluoride in L through six N-H¡¤¡¤¡¤F^– interactions with a distorted trigonal-prismatic geometry, whereas sulfate and carbonate induce dimeric assemblies of L in complexes 2 and 3, resp. In the case of sulfate, a tight dimeric capsular assembly of ca. 9.5 ? is observed through 15 N-H¡¤¡¤¡¤O interactions, whereas carbonate forms a sandwich-like dimeric mol. aggregation through 14 N-H¡¤¡¤¡¤O interactions. In the presence of tetrabutylammonium iodide as the phase transfer agent, L has shown ca. 70 % extraction of fluoride (based on L) and ca. 40 % extraction of sulfate (based on L) from aqueous solutions using an anion-exchange-based liquid-liquid extraction strategy. Extraction of these anions is unambiguously demonstrated by ¹H NMR, ¹⁹F NMR and FTIR spectroscopy, PXRD and single-crystal X-ray diffraction studies.

European Journal of Inorganic Chemistry published new progress about 17351-62-1. 17351-62-1 belongs to catalysis-chemistry, auxiliary class Salt,Amine, name is Tetrabutylammonium hydrogencarbonate, and the molecular formula is C17H37NO3, Application of Tetrabutylammonium hydrogencarbonate.

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

Ekner, Holly published the artcileDetermination of polycyclic aromatic hydrocarbons in commercial olive oils by HPLC/GC/MS – Occurrence, composition and sources, Synthetic Route of 191-07-1, the publication is Food Control (2022), 108528, database is CAplus.

Polycyclic aromatic hydrocarbons (PAHs) are a large class of organic compounds produced from incomplete combustion. Many PAHs are mutagenic and some are carcinogenic and pose a health risk to humans. Dietary intake of PAHs is a major route of exposure, where fats and edible oils are important contributors to overall dietary PAH exposure. Composed of hundreds of individual compounds as a complex mixture, only 16 PAHs are typically monitored in food and the environment. In this present study we analyzed 16 com. olive oil samples from different countries of origin and type (virgin or refined oil) for their content of 45 PAHs using a high-performance liquid chromatograph coupled to a gas chromatograph with a mass spectrometric detector. The content of the 45 PAHs varied between 9.17 and 94.7¦Ìg/kg (median: 30.1¦Ìg/kg) in the different olive oil samples. Only one sample didn’t meet the regulatory threshold levels for PAHs. The compositional profile of PAHs across the olive oil samples showed a high abundance of PAHs of lower mol. weights, and a large contribution of alkylated PAHs regardless of olive oil type. Direct contact with diesel exhaust emissions from mech. harvesters has previously shown to affect PAH levels in olive oils. Using diagnostic PAH ratios, biomass/coal combustion and/or petroleum/fossil fuel combustion were indicated as important sources. Source apportionment by Pos. Matrix Factorization revealed diesel exhaust emission and biomass combustion as the two major sources of PAHs followed by traffic emissions. This suggests that air quality may have a considerable impact on pollution levels in olive oils and thus indirectly affect dietary exposure.

Food Control 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, Synthetic Route of 191-07-1.

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

Wang, Lizhi published the artcileOn-site measured emission factors of polycyclic aromatic hydrocarbons for different types of marine vessels, Safety of Coronene, the publication is Environmental Pollution (Oxford, United Kingdom) (2022), 118782, database is CAplus and MEDLINE.

A portable emission sampling system was used to perform on-site measurements of the emission factors (EFs; quantities of pollutants emitted per unit of energy consumed) of 29 polycyclic aromatic hydrocarbons (PAHs) for five types of marine vessels using light diesel in Hainan Province, China. Both gaseous- and particulate-phase PAHs from vessel emissions were sampled and measured using gas chromatog. coupled with mass spectrometry (GC-MS), and the PAH EFs were calculated based on the carbon mass balance method. The average EFs of gaseous- and particulate-phase PAHs were 6.2 ¡À 7.8 and 17 ¡À 26 mg/kg, with naphthalene (NAP) and phenanthrene (PHE) dominating the gaseous- and particulate-phase PAH emissions, resp. Among the five types of vessels, the EFs for small fishing boats were significantly higher than those for other types of vessels, and the lowest EFs were found for tug boats. Composition profiles and typical isomer ratios of PAHs were calculated for five types of vessels. Particulate-phase PAHs accounted for 63 ¡À 16% of the total emissions of 29 PAH species, and the particulate/gaseous-phase partitioning of PAHs was dominated by organic carbon (OC) absorption rather than black carbon (BC) adsorption. Emission factors of PAHs under different activity conditions were measured and calculated, and relatively higher EFs were found in the maneuvering mode for medium fishing boats and in the operating mode for engineering vessels. No significant differences were found among the PAH composition profiles under different activity conditions.

Environmental Pollution (Oxford, United Kingdom) 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 C10H10O6, Safety of Coronene.

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

Tran, Thi-Nguyet published the artcileChemical Reactivity and the Influence of Initiators on the Epoxidized Vegetable Oil/Dicarboxylic Acid System, SDS of cas: 119-80-2, the publication is Macromolecules (Washington, DC, United States) (2020), 53(7), 2526-2538, database is CAplus.

In a sustainable development context, epoxidized vegetable oils (EVO) have unlimited and promising future prospects as renewable and environmentally friendly feedstock. The only drawback to their use is their low and non-selective reactivity compared to the aromatic epoxides. Properly, a small optimized amount of “true” initiators can overcome this issue and also beneficially serve in properties such as glass transition, modulus, strength, elongation at break, and chem. resistance. This paper presents efforts to understand and identify the initiator’s effect to more accurately predict how to select a good initiator on EVO/dicarboxylic acid systems. A new bio-based reprocessable epoxy resin was prepared from epoxidized linseed oil (ELO) and 2,2′-dithiodibenzoic acid (DTBA). The evolution of the chem. structures and the reactions’ mechanisms were systematically studied by in situ Fourier transform IR (FT-IR) and NMR (NMR) spectroscopies and differential scanning calorimetry (DSC). A screening of 10 initiators was performed for the ELO/DTBA crosslinking reaction. The influence of the initiator’s structure, basicity, and nucleophilicity was assessed and ranked in terms of the kinetic response including the epoxy-acid reaction rate and the percentage of functional group consumption. An excellent effect achieved by imidazole as an initiator was demonstrated. An attempt has been proposed to corroborate the exptl. values with the results of quantum chem. calculations

Macromolecules (Washington, DC, United States) 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 C12H20O6, SDS of cas: 119-80-2.

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