Month: December 2022

Mohamadi, Ali published the artcileBrightly Luminescent and Kinetically Inert Lanthanide Bioprobes Based on Linear and Preorganized Chelators, Recommanded Product: N1,N2-Dibenzylethane-1,2-diamine, the publication is Bioconjugate Chemistry (2016), 27(10), 2540-2548, database is CAplus and MEDLINE.

The synthesis, photophys. properties, and kinetic stability of a series of water-soluble, highly emissive Tb(III) and Eu(III) complexes featuring triethylenetetraamine hexaacetic acid (TTHA) and cyclohexyl triethylenetetraamine hexaacetic acid (cyTTHA) chelator scaffolds and carbostyril sensitizers are reported. The unique and modular design of the chelators gives rise to striking quantum yields of emission in aqueous solutions (up to 54%) as well as the characteristic lanthanides’ photophys. properties (long excited-state lifetimes, large effective Stokes shifts, and narrow emission peaks). Furthermore, the preorganized chelators (L3, L4, and L6) bind metal within minutes at ambient temperature yet exhibit substantial resistance to transchelation in the presence of a challenge solution (EDTA, 1 mM). Moreover, the Eu(III) complex of L4 remains stably luminescent in HeLa cells over hours, demonstrating the suitability of these compounds for live-cell imaging applications. Representative chelators suitable for derivatization and protein bioconjugation were also prepared that were functionalized with clickable azide and alkyne moieties, biotin, and trimethoprim (TMP). With exceptional long-wavelength brightness, enhanced kinetic inertness, and an adaptable synthetic route, the reported lanthanide complexes are promising probes and labels for time-gated bioanal., biosensing, and optical microscopy.

Bioconjugate Chemistry 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 C16H20N2, Recommanded Product: N1,N2-Dibenzylethane-1,2-diamine.

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

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

Li, Jian-Yuan published the artcilePalladium-Catalyzed Hydroxycarbonylation of (Hetero)aryl Halides for DNA-Encoded Chemical Library Synthesis, Application of 4-(Phenoxymethyl)benzoic acid, the publication is Bioconjugate Chemistry (2019), 30(8), 2209-2215, database is CAplus and MEDLINE.

A strategy for DNA-compatible, palladium-catalyzed hydroxycarbonylation of (hetero)aryl halides on DNA-chem. conjugates has been developed. This method generally provided the corresponding carboxylic acids in moderate to very good conversions for (hetero)aryl iodides and bromides, and in poor to moderate conversions for (hetero)aryl chlorides. These conditions were further validated by application within a DNA-encoded chem. library synthesis and subsequent discovery of enriched features from the library in selection experiments against two protein targets.

Bioconjugate Chemistry published new progress about 31719-76-3. 31719-76-3 belongs to catalysis-chemistry, auxiliary class Carboxylic acid,Benzene,Ether, name is 4-(Phenoxymethyl)benzoic acid, and the molecular formula is C14H12O3, Application of 4-(Phenoxymethyl)benzoic acid.

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

Mauro, Chiara Di published the artcileInfluence of the presence of disulphide bonds in aromatic or aliphatic dicarboxylic acid hardeners used to produce reprocessable epoxidized thermosets, Related Products of catalysis-chemistry, the publication is Polymers (Basel, Switzerland) (2021), 13(4), 534, database is CAplus and MEDLINE.

The design of polymers from renewable resources with recycling potential comes from economic and environmental problems. This work focused on the impact of disulfide bonds in the dicarboxylic acids reactions with three epoxidized vegetable oils (EVOs). For the first time, the comparison between aromatic vs. aliphatic dicarboxylic acids, containing or not S-S bonds with EVOs was discussed and evaluated by dynamic scanning calorimetry. The obtained thermosets showed reprocessability, by the dual dynamic exchange mechanism. The virgin and reprocessed materials were characterized and the thermomech. properties were compared. The thermosets derived from EVOs with high epoxy content combined with aromatic diacids containing disulfide bridges showed high glass transition values (~111¡ãC), high crosslink densities and good solvent stability.

Polymers (Basel, Switzerland) 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, Related Products of catalysis-chemistry.

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

Fujiwara, Daisuke published the artcileChemical Modification of Phage-Displayed Helix-Loop-Helix Peptides to Construct Kinase-Focused Libraries, COA of Formula: C20H19NO4, the publication is ChemBioChem (2021), 22(24), 3406-3409, database is CAplus and MEDLINE.

Conformationally constrained peptides hold promise as mol. tools in chem. biol. and as a new modality in drug discovery. The construction and screening of a target-focused library could be a promising approach for the generation of de novo ligands or inhibitors against target proteins. Here, we have prepared a protein kinase-focused library by chem. modifying helix-loop-helix (HLH) peptides displayed on phage and subsequently tethered to adenosine. The library was screened against aurora kinase A (AurA). The selected HLH peptide Bip-3 retained the ¦Á-helical structure and bound to AurA with a K_D value of 13.7 ¦ÌM. Bip-3 and the adenosine-tethered peptide Bip-3-Adc provided IC₅₀ values of 103 ¦ÌM and 7.7 ¦ÌM, resp., suggesting that Bip-3-Adc bivalently inhibited AurA. In addition, the selectivity of Bip-3-Adc to several protein kinases was tested, and was highest against AurA. These results demonstrate that chem. modification can enable the construction of a kinase-focused library of phage-displayed HLH peptides.

ChemBioChem 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

Ferreira Azevedo, L. published the artcileThe alternative analog plasticizer BPS displays similar phenotypic and metabolomic responses to BPA in HepG2 and INS-1E cells, Computed Properties of 6217-54-5, the publication is Food and Chemical Toxicology (2022), 167(Suppl._1), 113266, database is CAplus and MEDLINE.

Bisphenols A (BPA) and S (BPS) are endocrine-disrupting chems. that affect energy metabolism, leading to impairment of glucose and lipid homeostasis. We aimed at identifying metabolic pathways regulated by both compounds in human liver cells and rat pancreatic ¦Â-cells that could impair energy homeostasis regulation. We assessed the effects on growth, proliferation, and viability of hepatocarcinoma (HepG2) and insulinoma (INS-1E) cells exposed to either BPA or BPS in a full range concentration between 0.001 and 100¦ÌM. Both the dose and duration of exposure caused a differential response on growth and viability of both cells. Effects were more pronounced on HepG2, as these cells exhibited non-linear dose-responses following exposure to xenobiotics. For INS-1E, effect was observed only at the highest concentration In addition, we profiled their intracellular state by untargeted metabolomics at 24, 48, and 72 h of exposure. This anal. revealed time- and dose-dependently mol. changes for HepG2 and INS-1E that were similar between BPA and BPS. Both increased levels of inflammatory mediators, such as metabolites pertaining to linolenic and linoleic acid metabolic pathway. In summary, this study shows that BPS also disrupts mol. functions in cells that regulate energy homeostasis, displaying similar but less pronounced responses than BPA.

Food and Chemical Toxicology 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, Computed Properties of 6217-54-5.

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

Spitzner, R. published the artcileKetovinylization of thiocarbamides and thioureas. On the ambidence of the thioamido function, HPLC of Formula: 6972-05-0, the publication is Tetrahedron (1982), 38(7), 927-36, database is CAplus.

Thiocarbamides and thioureas reacted as ambident systems with ¦Â-chlorovinyl ketones to give (S)-[(Z)-ketovinyl] salts. E.g., addition reaction of PhCSNH₂ with PhCOCH:CHCl in HCO₂H/HClO₄ for 1-2 h gave 78% (Z)-PhCOCH:CHSCPh:N⁺H₂ ClO₄^–. The ketovinyl salts obtained from monoprotic thiocarbamides and thioureas underwent deprotonation to give (S)-[(Z)-ketovinyl]thioimidate esters or -isothioureas, which isomerized intramolecularly on heating. E.g., deprotonation of (Z)-4-MeOC₆H₄COCH:CHSCPh:N⁺HPh ClO₄^– gave 82% (Z)-4-MeOC₆H₄COCH:CHSCPh:NPh, which on heating in PhMe gave (E)-4-MeOC₆H₄COCH:CHSCPh:NPh. Lithiated monoprotic thiocarbonamides reacted with ¦Â-chlorovinyl ketones to give N-[(E)-ketovinyl]thiocarbonamides, whereas lithiated thioureas gave S-[(E)-ketovinyl]isothioureas, which rearranged to the N-[(E)-ketovinyl]thioureas under mild conditions. E.g., lithiation and addition reaction of PhCSNHPh with PhCOCH:CHCl gave 59% (E)-PhCOCH:CHNPhCSPh, whereas similar treatment of Me₂NC(S)NHPh gave (E)-PhCOCH:CHSC(:NPh)NMe₂, which above room temperature gave (E)-PhCOCH:CHNPhC(S)NMe₂.

Tetrahedron 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 C8H5F3N4, HPLC of Formula: 6972-05-0.

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

Biju, Vasudevanpillai published the artcileIntermittent Single-Molecule Interfacial Electron Transfer Dynamics, Synthetic Route of 10510-54-0, the publication is Journal of the American Chemical Society (2004), 126(30), 9374-9381, database is CAplus and MEDLINE.

The authors report on single-mol. studies of photosensitized interfacial electron transfer (ET) processes in Coumarin 343 (C343)-TiO₂ nanoparticles (NP) and Cresyl Violet (CV⁺)-TiO₂ NP systems, using time-correlated single-photon counting coupled with scanning confocal fluorescence microscopy. Fluorescence intensity trajectories of individual dye mols. adsorbed on a semiconductor NP surface showed fluorescence fluctuations and blinking, with time constants distributed from milliseconds to seconds. The fluorescence fluctuation dynamics were found to be inhomogeneous from mol. to mol. and from time to time, showing significant static and dynamic disorders in the interfacial ET reaction dynamics. The authors attribute fluorescence fluctuations to the interfacial ET reaction rate fluctuations, associating redox reactivity intermittency with the fluctuations of mol.-TiO₂ electronic and Franck-Condon coupling. Intermittent interfacial ET dynamics of individual mols. could be characteristic of a surface chem. reaction strongly involved with and regulated by mol.-surface interactions. The intermittent interfacial reaction dynamics that likely occur among single mols. in other interfacial and surface chem. processes can typically be observed by single-mol. studies but not by conventional ensemble-averaged experiments

Journal of the American Chemical Society 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, Synthetic Route of 10510-54-0.

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

Wang, Yi published the artcileCoronene and Phthalocyanine Trapping Efficiency of a Two-Dimensional Kagome Host-Nanoarchitecture, Safety of Coronene, the publication is Nanomaterials (2022), 12(5), 775, database is CAplus and MEDLINE.

The trapping of coronene and zinc phthalocyanine (ZnPc) mols. at low concentration by a two-dimensional self-assembled nanoarchitecture of a push-pull dye is investigated using scanning tunneling microscopy (STM) at the liquid-solid interface. The push-pull mols. adopt an L-shaped conformation and self-assemble on a graphite surface into a hydrogen-bonded Kagome’ network with porous hexagonal cavities. This porous host-structure is used to trap coronene and ZnPc guest mols. STM images reveal that only 11% of the Kagome network cavities are filled with coronene mols. In addition, these guest mols. are not locked in the host-network and are desorbing from the surface. In contrast, STM results reveal that the occupancy of the Kagome’; cavities by ZnPc evolves linearly with time until 95% are occupied and that the host structure cavities are all occupied after few hours.

Nanomaterials 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 C12H14O2, Safety of Coronene.

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

Hartman, Christian K. published the artcileMapping the Intricate Reactivity of Nanojars toward Molecules of Varying Acidity and Their Conjugate Bases Leading To Exchange of Pyrazolate Ligands, Product Details of C17H37NO3, the publication is Inorganic Chemistry (2017), 56(17), 10609-10624, database is CAplus and MEDLINE.

A comprehensive reactivity study of nanojars toward 18 different acidic compounds with varying pK_a, including 12 different carboxylic acids (both aliphatic and aromatic mono- and dicarboxylic acids), p-toluenesulfonic acid, hydrogen sulfate, hydrogen carbonate, carbonic acid, 1-decanethiol, and methanol, as well as four different conjugate bases (formate, acetate, benzoate, 2-bromoethanesulfonate) was carried out with the aid of electrospray-ionization mass spectrometry. Thus, the effect on nanojar substitution and breakdown pattern of a number of variables, such as concentration of reagent (acid or conjugate base), acidity of reagent (pK_a), effect of acid vs. conjugate base, steric effects, aromaticity, incarcerated anion and size of the nanojar, is evaluated. Of the substitution and breakdown products identified by mass spectrometry, acetate-substituted nanojars (Bu₄N)₂[CO₃?{Cu₂₇(¦Ì-OH)₂₇(¦Ì-pz)_27-x(¦Ì-CH₃COO)_x}] (x = 1 and 2), as well as dimeric complexes (Bu₄N)₂[Cu₂(¦Ì-pz)₂A₂] (A = CO₃^2- and SO₄^2-) were isolated and characterized by single-crystal x-ray diffraction. The prepared complexes are (Bu₄N)₂[CO₃?{Cu_27-x(¦Ì-pz)_27-x(¦Ì-CH₃COO)_x}](C₆H₅CH₃)₆ (x = 1 and 2) (1), (Bu₄N)₂[Cu₂(¦Ì-pz)₂(SO₄)₂] (2), (Bu₄N)₂[Cu₂(¦Ì-pz)₂(CO₃)₂] (3) and (Bu₄N)₂[Cu₂(¦Ì-pz)₂(CO₃)(SO₄)]¡¤CH₃OH (4). This study offers a detailed understanding of the behavior of nanojars of various sizes and with different incarcerated anions in the presence of the above-mentioned compounds at varying concentrations and tests the limits of the pyrazolate/carboxylate structural analogy in multinuclear metal complexes. The results point to the possibility of obtaining functionalized nanojars via pyrazolate/carboxylate ligand exchange, an aid in the design of anion extraction processes using nanojars or similar complexes as extracting agents.

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, Product Details of C17H37NO3.

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