Tag: M.W=300-350

Dent, Matthew R. published the artcileElectron Paramagnetic Resonance Spectroscopy as a Probe of Hydrogen Bonding in Heme-Thiolate Proteins, HPLC of Formula: 119-80-2, the publication is Inorganic Chemistry (2019), 58(23), 16011-16027, database is CAplus and MEDLINE.

Despite utilizing a common cofactor binding motif, hemoproteins bearing a cysteine-derived thiolate ligand (heme-thiolate proteins) are involved in a diverse array of biol. processes ranging from drug metabolism to transcriptional regulation. Though the origin of heme-thiolate functional divergence is not well understood, growing evidence suggests that the hydrogen bonding (H-bonding) environment surrounding the Fe-coordinating thiolate influences protein function. Outside of X-ray crystallog., few methods exist to characterize these critical H-bonding interactions. ESR (EPR) spectra of heme-thiolate proteins bearing a six-coordinate, Fe(III) heme exhibit uniquely narrow low-spin (S = 1/2), rhombic signals, which are sensitive to changes in the heme-thiolate H-bonding environment. To establish a well-defined relationship between the magnitude of g-value dispersion in this unique EPR signal and the strength of the heme-thiolate H-bonding environment, we synthesized and characterized of a series of six-coordinate, aryl-thiolate-ligated Fe(III) porphyrin complexes bearing a tunable intramol. H-bond. Spectroscopic investigation of these complexes revealed a direct correlation between H-bond strength and g-value dispersion in the rhombic EPR signal. Using d. functional theory (DFT), we elucidated the electronic origins of the narrow, rhombic EPR signal in heme-thiolates, which arises from an Fe-S p_¦Ð-d_¦Ð bonding interaction. Computational anal. of the intramolecularly H-bonded heme-thiolate models revealed that H-bond donation to the coordinating thiolate reduces thiolate donor strength and weakens this Fe-S interaction, giving rise to larger g-value dispersion. By defining the relationship between heme-thiolate electronic structure and rhombic EPR signal, it is possible to compare thiolate donor strengths among heme-thiolate proteins through anal. of low-spin, Fe(III) EPR spectra. Thus, this study establishes EPR spectroscopy as a valuable tool for exploring how second coordination sphere effects influence heme-thiolate protein function. Herein, we utilize exptl. and computational methods to enumerate the electronic origin of the anisotropic rhombic EPR signal characteristic of thiolate-ligated hemoproteins, and we illustrate how EPR spectroscopy may be used to probe the second coordination sphere of heme-bound thiolate. Through synthesis and characterization of porphyrin-thiolate models bearing a tunable, intramol. H-bond, we establish a direct correlation between the magnitude of g-shifts observed in the rhombic EPR signal and thiolate H-bond strength.

Inorganic 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 C14H10O4S2, HPLC of Formula: 119-80-2.

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

Sardenne, Fany published the artcileChanges in lipid and fatty acid contents of gonad during the reproductive cycle of the Mediterranean swordfish Xiphias gladius, Recommanded Product: Docosahexaenoic Acid, the publication is Marine Environmental Research (2022), 105668, database is CAplus and MEDLINE.

Swordfish Xiphias gladius is a large pelagic fish distributed worldwide and exploited for human consumption, however there is limited knowledge about its reproductive biol., especially regarding lipid dynamic in gonads. In teleost fish, reproductive success and offspring survival are associated to lipid availability for gamete synthesis. This study investigated the lipid composition, including lipid classes and fatty acids (FA) of cell membrane and reserve lipids (i.e., polar and neutral lipids, resp.; PL and NL), along female and male gonad development of a swordfish population from waters surrounding Corsica Island in the Mediterranean Sea. Overall, swordfish gonads contained <2% wet weight of total lipids, with testes and ovaries having similar fat content. Lipid classes and FA concentrations remained unchanged during testes maturation. However, concentrations of phosphatidyl choline (PL), triacylglycerol (NL), and some FA (16:0, 18:1n-9, and 22:6n-3) followed an “inverted U-shaped” relationship with the ovarian maturation. In both PL and NL, 22:6n-3 was the main polyunsaturated FA (>20% of total FA), while 20:5n-3 and 20:4n-6 were minor (3-6% of total FA) and varied little with maturation. 22:6n-3 and 18:1n-9 were selectively allocated to the ovarian maturation (increased in concentration and in proportion with maturation) until spawning. Finally, swordfish gonads might represent a good food source for humans given that 150 g of swordfish ovaries can cover the daily requirements in omega-3 for humans, but research on pollutants should also be conducted to evaluate their implications on the reproduction output of this species, and on the safety of swordfish gonads for human consumption.

Marine Environmental Research 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

Spears, Richard J. published the artcileA novel thiol-labile cysteine protecting group for peptide synthesis based on a pyridazinedione (PD) scaffold, HPLC of Formula: 71989-31-6, the publication is Chemical Communications (Cambridge, United Kingdom) (2022), 58(5), 645-648, database is CAplus and MEDLINE.

Herein we report a thiol-labile cysteine protecting group based on an unsaturated pyridazinedione (PD) scaffold. We establish compatibility of the PD in conventional solid phase peptide synthesis (SPPS), showcasing this in the on-resin synthesis of biol. relevant oxytocin. Furthermore, we establish the applicability of the PD protecting group towards both microwave-assisted SPPS and native chem. ligation (NCL) in a model system.

Chemical Communications (Cambridge, United Kingdom) 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 C11H21BF4N2O2, HPLC of Formula: 71989-31-6.

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

Peterse, Evert published the artcileSolid-phase synthesis of macrocyclic peptides via side-chain anchoring of the ornithine ¦Ä-amine, Recommanded Product: Fmoc-Pro-OH, the publication is European Journal of Organic Chemistry (2022), 2022(11), e202101341, database is CAplus.

Cyclic peptides represent a popular class of macrocyclic drug candidates and therefore their solid phase synthesis has attracted much attention. In this contribution we present an efficient method of side-chain anchoring for ornithine and lysine residues to be used in the standard Fmoc-based (Fmoc = 9-fluorenylmethoxycarbonyl) synthesis of cyclic peptides via on-resin cyclization. We demonstrate that the side chain of ornithine and lysine protected with N-Boc-group (Boc = tert-butoxycarbonyl) can efficiently be converted to the isocyanate which is then immobilized on Wang-type resin in almost quant. yield. We further show the synthesis of four biol. active cyclic peptides employing the side chain ornithine anchoring. Our method is at least on a par with the previously reported methodologies in terms of yield and the purity of the final products and is arguably operationally more straightforward.

European 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, Recommanded Product: Fmoc-Pro-OH.

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

Bateni, Fatemeh published the artcileDistribution, source and ecological risk assessment of polycyclic aromatic hydrocarbons in the sediments of northern part of the Persian Gulf, Recommanded Product: Coronene, the publication is Chemosphere (2022), 133859, database is CAplus and MEDLINE.

Distribution, sources, and ecol. risk of 43 compounds of polycyclic aromatic hydrocarbons (PAHs) in surficial sediments of the Persian Gulf were investigated. The sediments were sampled from 60 offshore stations during an oceanog. cruise in the winter of 2012. Gas chromatog. high-resolution mass spectrometry was used for the PAHs determinations in sediment samples. The concentrations of 21 parent PAHs, 7 methylated PAHs, 11 oxygenated PAHs and 4 nitrated PAHs were 9.0-201.5 ng g^-1 dw, 3.3-60.3 ng g^-1 dw, 15.2-172.7 ng g^-1 dw and 0.1-8.3 ng g^-1 dw, resp. Among 21 parental PAHs, naphthalene (29.35 ng g-1 dw), phenanthrene (4.6 ng g-1 dw), and pyrene (3.18 ng g-1 dw) were the most abundant compound 1-acenaphthenone (43.41 ng g-1 dw) and 2-methylnaphthalene (7.15 ng g-1 dw) showed the highest concentration in the oxy- and methyl-PAHs, resp. The concentrations of nitro-PAHs were between not detected to 4 ng g-1 dw. According to the ecol. risk assessment, the calculated total toxicity of PAHs was at below the lethal level on benthic organisms in all stations in the Persian Gulf, but there is risk of toxicity for the benthic organism in the Gulf of Oman (from the Strait of Hormuz to Jask). In general, nitrogenated and oxygenated derivatives did not show a significant risk in the study area. Based on the diagnostic ratios, the mixed sources (both petrogenic and pyrogenic) and pyrogenic sources have been identified for PAHs. Biomass combustion source has been identified for the stations near flares and gas fields. Principle component anal.-multivariate linear regression anal. for source identification shows that maritime traffic, abundant flares that burn the gas in oil, gas fields and dust storms have a major impact on the production of PAHs in this area.

Chemosphere 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, Recommanded Product: Coronene.

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

Tamoradi, Taiebeh published the artcileImmobilization of a nickel complex onto functionalized Fe₃O₄ nanoparticles: a green and recyclable catalyst for synthesis of 5-substituted 1H-tetrazoles and oxidation reactions, Product Details of C14H10O4S2, the publication is Research on Chemical Intermediates (2018), 44(2), 1363-1380, database is CAplus.

In the present research, a magnetically recoverable catalyst was easily prepared by anchoring nickel onto the surface of organically modified magnetite nanoparticles. Characterization of the prepared nanostructure was performed by various physicochem. techniques such as FTIR spectroscopy, SEM, TEM, energy-dispersive x-ray spectroscopy, inductively coupled plasma optical emission spectroscopy, X-ray diffraction, TGA and vibrating sample magnetometer measurements. The catalytic behavior of the prepared nanohybrid as an efficient catalyst was successfully probed in the oxidation of sulfides, oxidative coupling of thiols and synthesis of 5-substituted 1H-tetrazoles. This method has significant advantages, including high yield, green reaction conditions, short reaction time, easy separation and workup, as well as the ability to tolerate a wide variety of substitutions in the reagents.

Research on Chemical Intermediates 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 C8H5IO, Product Details of C14H10O4S2.

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

Tran, Thi-Nguyet published the artcileMonitoring the structure-reactivity relationship in epoxidized perilla and safflower oil thermosetting resins, COA of Formula: C14H10O4S2, the publication is Polymer Chemistry (2020), 11(31), 5088-5097, database is CAplus.

For the first time, the effect of reactant structure, stoichiometry and heating rate on the reactivity of epoxidized perilla oil (EPLO) and epoxidized safflower oil (ESFO) with dicarboxylic acids (DCAs) was studied using in situ FT-IR. The epoxy content in the monomer structure was found to affect the copolymerization system’s reactivity, with epoxidized linseed oil (ELO) considered as a reference In this study we discuss also the influence of the DCA structure on the copolymerization reactivity. Two aromatic diacids, dithiodibenzoic acid (DTBA) and diphenic acid (DPA), were studied and compared in the copolymerization of the 3 EVOs, in the presence of imidazole (IM) initiator. The kinetics of these reactions were followed by in situ FT-IR. The corresponding activation energies were calculated via different kinetic models. These data highlight the higher reactivity of the EPLO monomer and the DTBA hardener.

Polymer 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 C20H28B2O4S2, COA of Formula: C14H10O4S2.

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

Nithipatikom, Kasem published the artcileCharacterization and application of Raman labels for confocal Raman microspectroscopic detection of cellular proteins in single cells, COA of Formula: C18H15N3O3, the publication is Analytical Biochemistry (2003), 322(2), 198-207, database is CAplus and MEDLINE.

A method using confocal Raman microspectroscopy for the detection of cellular proteins in single intact cells was developed. Two approaches were used to improve the detection of these cellular components. First, compounds with high Raman scattering were investigated for potential use as Raman labels. Raman labels were conjugated to either biomols. or biotin and used as markers in the detection of cellular enzymes and receptors. Second, silver colloids were used to increase the surface-enhanced Raman scatter (SERS) of these Raman labels. Cresyl violet and dimethylaminoazobenzene are Raman labels that provide very sensitive SERS detection by a confocal Raman microscope with a HeNe laser at wavelength of 632.8 nm. The detection of 12-lipoxygenase and cyclooxygenase-1 in single bovine coronary artery endothelial cells and the binding of angiotensin II to its receptors in zona glomerulosa cells was demonstrated.

Analytical Biochemistry 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 C18H15N3O3, COA of Formula: C18H15N3O3.

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

Sera, Yoichi published the artcileSweeping on a microchip: concentration profiles of the focused zone in micellar electrokinetic chromatography, COA of Formula: C18H15N3O3, the publication is Electrophoresis (2001), 22(16), 3509-3513, database is CAplus and MEDLINE.

Online sample concentration by sweeping was studied in microchip micellar electrokinetic chromatog. (MEKC), By changing the distance between the injection cross and the detection points, the profile of the concentration process and the diffusion process in sweeping was elucidated. Rhodamine B injected for 4 s was best concentrated by sweeping at 9.4 mm from the injection cross and the enhancement factor was 450. At the longer distance from this point the peak of Rhodamine B was broadened and diluted by diffusion. The diffusion constant of Rhodamine B calculated from the experiment was 5.7 ¡Á 10^-6 cm² s^-1. The mixture of rhodamine B, sulforhodamine B, and cresyl fast violet was concentrated by sweeping and separated by MEKC at the same time.

Electrophoresis 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 C5H8N2O, COA of Formula: C18H15N3O3.

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

Menci, Ruggero published the artcileSupplementing goats’ diet with sainfoin pellets (versus alfalfa) modifies cheese sensory properties and fatty acid profile, Recommanded Product: Docosahexaenoic Acid, the publication is International Dairy Journal (2022), 105398, database is CAplus.

In two different goat farms, producing Picodon and Mutschli cheese resp., two groups of lactating goats were fed alfalfa pellets (ALF) or sainfoin pellets (SNF) for 6 wk. The cheeses produced at the end of the trial were analyzed for sensory properties, composition, fatty acid profile, proteolysis, and rheol. The SNF Picodon had higher ”goat” and ”farm” aroma and odor, and higher bitter taste, compared with the ALF Picodon. The SNF Picodon showed lower dry matter than the ALF Picodon, leading to differences in texture and mouthfeel. The SNF Mutschli had a different mouthfeel than the ALF Mutschli. In a triangle test, consumers were able to perceive a difference in both Picodon and Mutschli between ALF and SNF groups. In both Picodon and Mutschli, feeding sainfoin increased cheese proteolysis and modified cheese fatty acid profile, resulting in higher polyunsaturated fatty acids proportion and lower n-6/n-3 ratio.

International Dairy Journal 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