Catalysis-chemistry

Sheng, Le published the artcileHydrazone bond-oriented molecularly imprinted nanocomposites for the selective separation of protein via the well-defined recognition sites, Related Products of catalysis-chemistry, the publication is Microchimica Acta (2022), 189(7), 246, database is CAplus and MEDLINE.

The development of hydrazone bond-oriented epitope imprinting strategy is reported to synthesize the polymeric binders for the selective recognition of a protein-¦Â₂-microglobulin through either its N- or C-terminal epitope. The dynamic reversibility of hydrazone bond facilitated not only the oriented assembly of the template peptide hydrazides onto the substrate but also the efficient removal of them from the imprinted cavities. The well-defined surface imprinted layer was successfully constructed through the precise control over the polymerization of silicate esters. Binding performance of the C-terminal peptide imprinted nanocomposite was significantly improved after tuning the non-covalent interactions using the sequence-matching aromatic co-monomers. The dissociation constant (K_d) between the optimized nanocomposite and epitope peptide was 0.5 ¦Ìmol L^-1. The nanomaterial was utilized for the selective extraction and determination of ¦Â₂-microglobulin from human urine by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) and HPLC-UV with satisfied recoveries of 93.1-112.3% in a concentration range 1.0-50.0 ¦Ìg¡¤mL^-1.

Microchimica Acta 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 C15H14Cl2S2, Related Products of catalysis-chemistry.

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

Zhang, Xin published the artcileSynthesis of bismaleimides bearing electron-donating chromophores and their fluorescence behavior during copolymerization, Application of Bis(4-nitrophenyl)amine, the publication is Macromolecules (2003), 36(9), 3115-3127, database is CAplus.

Bismaleimides and bisitaconimides bearing diphenylmethylamine, triphenylamine, or 2,5-diphenyl-1,3,4-oxadiazole chromophores (symbolized as A₍₌₎-D_(x)-A₍₌₎), as well as their saturated model compounds were synthesized, and their steady-state and time-resolved fluorescence spectra were investigated. These A₍₌₎-D_(x)-A₍₌₎ monomers display strong intramol. fluorescence quenching. Their fluorescence quantum yields and lifetimes are generally lower than those of their model compounds It was found that the electron-poor C:C bond of maleimide and itaconimide units (A₍₌₎) plays a key role in the intramol. quenching, which is correlated to the electron-accepting ability of A₍₌₎ and the geometry arrangement between A₍₌₎ and electron-donating chromophore (D_(x)). The intramol. quenching was attributed to an intramol. charge transfer interaction, which was confirmed by intermol. fluorescence quenching and time-resolved fluorescence studies. On the basis of the intramol. quenching, a new fluorescence approach can be developed to monitor the process of the polymerization and curing of bismaleimides, which can directly reflect the C:C bond consumption during polymerization and curing. The new fluorescence approach can be utilized not only by an intrinsic fluorescence technique but also by an extrinsic fluorescence technique.

Macromolecules published new progress about 1821-27-8. 1821-27-8 belongs to catalysis-chemistry, auxiliary class Nitro Compound,Amine,Benzene, name is Bis(4-nitrophenyl)amine, and the molecular formula is C15H15OP, Application of Bis(4-nitrophenyl)amine.

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

Li, Yanli published the artcileCopper-Catalyzed Dynamic Kinetic C-P Cross-Coupling/Cyclization for the Concise Asymmetric Synthesis of Six-, Seven- and Eight-Membered P-Stereogenic Phosphorus Heterocycles, Recommanded Product: 4-Nitrophenylacetic acid, the publication is Angewandte Chemie, International Edition (2022), 61(24), e202117093, database is CAplus and MEDLINE.

A copper-catalyzed asym. aryl C-P cross-coupling/cyclization reaction was successfully developed via dynamic kinetic asym. transformation (DYKAT) under mild conditions. This study provides a general and simple method for the catalytic enantioselective synthesis of stable six-, seven- and eight-membered P-stereogenic phosphorus heterocycles with excellent enantioselectivities and moderate to high yields. One-pot gram-scale asym. synthesis of the P-stereogenic P-heterocycle from com. available materials was also successfully accomplished with excellent enantioselectivity and high yield.

Angewandte Chemie, International Edition published new progress about 104-03-0. 104-03-0 belongs to catalysis-chemistry, auxiliary class Nitro Compound,Carboxylic acid,Benzene, name is 4-Nitrophenylacetic acid, and the molecular formula is C8H7NO4, Recommanded Product: 4-Nitrophenylacetic acid.

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

Tang, Kaluo published the artcileStudies of trinuclear cadmium cluster complexes. Syntheses and crystal structures of [NMe₄][Cd₃(SC₆H₂Prⁱ₃-2,4,6)₇].C₅H₁₂ and [Cd₃(SC₆H₂Prⁱ₃-2,4,6)₆(HSC₆H₂Prⁱ₃-2,4,6)].CH₃OH.7H₂O, Application of 2,4,6-Triisopropylbenzenethiol, the publication is Journal of Coordination Chemistry (1994), 31(4), 305-20, database is CAplus.

By the reaction of a sterically hindered arenethiol, 2,4,6-(Me₂CH)₃C₆H₂SH (HL), with Cd(NO₃)₂.4H₂O under different conditions, the colorless salt of trinuclear cadmium cluster anion complex [NMe₄][Cd₃(L)₇].C₅H₁₂ (I) and the uncharged trinuclear cadmium complex [Cd₃(L)₆(HL)].MeOH.7H₂O (II) were synthesized and structurally characterized. Crystals of I are monoclinic, space group P2₁/n with a 19.629(6), b 25.608(9), c 25.450(9) ?, ¦Â 107.54(3)¡ã, Z = 4, R = 0.076 for 3839 observed reflections. Crystals of II are triclinic, space group, P1? with a 19.792(10), b 20.508(12), c 33.97(2) ?, ¦Á 85.81(5), ¦Â 86.77(5), ¦Ã 85.12(4)¡ã, Z = 4, R = 0.0921 for 8327 observed reflections. The core of the cluster anion of I is formed by a defect cubane unit with 3 cadmium and 4 sulfur atoms at its vertexes. Each cadmium atom exhibits tetrahedral coordination with 1 terminal sulfur, 2 doubly bridging sulfur and 1 triply bridging sulfur atoms. In complex II, 3 cadmium atoms are coordinated by 6 thiolate (RS^–) and 1 thiol (RSH) ligands. Two of 3 cadmium atoms have tetrahedral coordination and 1 is trigonal planar.

Journal of Coordination Chemistry published new progress about 22693-41-0. 22693-41-0 belongs to catalysis-chemistry, auxiliary class Other Functionalization Reagent, name is 2,4,6-Triisopropylbenzenethiol, and the molecular formula is C28H29NO4, Application of 2,4,6-Triisopropylbenzenethiol.

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

Zhang, Tianchu published the artcileInfluence of test cycle and fuel property on fuel consumption and exhaust emissions of a heavy-duty diesel engine, COA of Formula: C24H12, the publication is Energy (Oxford, United Kingdom) (2022), 244(Part_A), 122705, database is CAplus.

In this study, dynamometer engine tests were conducted to investigate the impact of test cycle and fuel type on fuel consumption and exhaust emissions of a heavy-duty diesel engine. This study presented novel approaches by utilizing comprehensive statistical anal. to assess these impacts on particulate matter (PM), PM-bound polycyclic aromatic hydrocarbons (PAHs), and multiple gaseous pollutants. Four types of fuels-two conventional diesels (X and Y) and each with 5% blend of biodiesel-were used under European Transient Cycle (ETC) and European Stationary Cycle (ESC). There were statistically significant higher fuel consumption and emission rates (by 9-73%) under ETC than ESC due to more occurrences of lower engine speeds and loads under ESC, and X fuels had higher emission rates of PM and carbon dioxides ([CO₂]; 2.1-13%) but lower rates of hydrocarbons ([THC]; 44%) attributed to higher cetane number, sulfur contents and b.ps. Compared with conventional diesel, biodiesel blend had slightly lower emission rates of PM, CO, and NO_X (1.7-6.6%) but higher fuel consumption (1%) and CO₂ and THC emission rates (0.9-2.1%). The results of this study contributed to the limited datasets on the interactive effects of test cycle with fuel property on diesel vehicle exhaust emissions.

Energy (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 C4H8Cl2S2, COA of Formula: C24H12.

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

Jing, Li published the artcileMetal-free oxidation of thiols by N-fluorobenzenesulfonimide: a rapid and efficient method to synthesize disulfides, Recommanded Product: 2,2′-Dithiodibenzoic acid, the publication is Youji Huaxue (2018), 38(3), 692-697, database is CAplus.

A simple and rapid method is developed for the oxidation of thiols to the corresponding disulfides using N-fluorobenzenesulfonimide (NFSI) as the oxidant without any contamination by over oxidation The synthetic protocol for disulfide bond formation proceeded efficiently under external base- and metal-free conditions with the advantages of simple operation, mild reaction conditions as well as short reaction times.

Youji Huaxue 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, Recommanded Product: 2,2′-Dithiodibenzoic acid.

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

Neufeldt, Sharon R. published the artcilePyridine N-Oxide vs Pyridine Substrates for Rh(III)-Catalyzed Oxidative C-H Bond Functionalization, Quality Control of 1293990-73-4, the publication is Journal of the American Chemical Society (2015), 137(31), 9843-9854, database is CAplus and MEDLINE.

The origin of the high reactivity and site selectivity of pyridine N-oxide substrates in O-pivaloyl hydroxamic acid-directed Rh(III)-catalyzed (4+2) annulation reactions with alkynes was investigated computationally. The reactions of the analogous pyridine derivatives were previously reported to be slower and to display poor site selectivity for functionalization of the C(2)-H vs the C(4)-H bonds of the pyridine ring. The N-oxide substrates are found to be more reactive overall because the directing group interacts more strongly with Rh. For N-oxide substrates, alkyne insertion is rate-limiting and selectivity-determining in the reaction with a dialkyl alkyne, but C-H activation can be selectivity-determining with other coupling partners such as terminal alkynes. The rates of reaction with a dialkyl alkyne at the two sites of a pyridine substrate are limited by two different steps: C-H activation is limiting for C(2)-functionalization, while alkyne insertion is limiting for C(4)-functionalization. Consistent with the observed poor site selectivity in the reaction of a pyridine substrate, the overall energy barriers for functionalization of the two positions are nearly identical. High C(2)-selectivity in the C-H activation step of the reaction of the N-oxide is due to a cooperative effect of the C-H Bronsted acidity, the strength of the forming C-Rh bond, and intramol. electrostatic interactions between the [Rh]Cp* and the heteroaryl moieties. On the other hand, some of these forces are in opposition in the case of the pyridine substrate, and C(4)-H activation is moderately favored overall. The alkyne insertion step is favored at C(2) over C(4) for both substrates, and this preference is largely influenced by electrostatic interactions between the alkyne and the heteroarene. Exptl. results that support these calculations, including kinetic isotope effect studies, H/D exchange studies, and results using a substituted pyridine, are also described.

Journal of the American Chemical Society published new progress about 1293990-73-4. 1293990-73-4 belongs to catalysis-chemistry, auxiliary class Aliphatic Chain, name is O-Pivaloylhydroxylamine trifluoromethanesulfonate, and the molecular formula is C6H12F3NO5S, Quality Control of 1293990-73-4.

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

Xi, Bao-Min published the artcileDrug metabolism-based design, synthesis, and bioactivities of 1-(2,6-dimethylphenoxy)-2-(3,4-dimethoxyphenylethylamino)propane hydrochloride (DDPH) analogs as ¦Á₁-adrenoceptors antagonists, Synthetic Route of 4230-93-7, the publication is Bioorganic & Medicinal Chemistry (2011), 19(2), 783-788, database is CAplus and MEDLINE.

1-(2,6-Dimethylphenoxy)-2-(3,4-dimethoxyphenylethylamino)propane hydrochloride (DDPH) is a potent ¦Á₁-adrenoceptor antagonist that is currently under Phase II clinic trials. However, the fast metabolism has restricted its further use. In this paper, 11 DDPH analogs were designed according to the probable metabolism pathways of DDPH, and featured the structures of halogen, Me, and cyano groups at the 3-, or 4-position of aromatic ring A to block the hydroxylation, and one hydroxyl group at the 3-, or 4-position of aromatic ring B to extend the duration time. These compounds were synthesized in moderate to good yields from the reductive amination of substituted phenoxyacetones with substituted phenylethylamines, and fully characterized with ¹H NMR, IR, and HRMS. Biol. evaluation indicated that most of the compounds exhibited strong blocking and moderate to good antihypertensive activities. It is clear that the compounds having 4-OH/3-OMe on group B exhibited higher blocking activities and longer duration time than their corresponding analogs having 4-OMe/3-OMe (and also 3-OH/4-OMe). Among them, compound 13 having bromo group at the 4-position of ring A and 4-OH/3-OMe on group B, exhibited the highest blocking activity, whereas compound 17 that had a Me group at the 4-position of ring A and a hydroxyl group at the 4-position of ring B, was more active than potent DDPH in terms of both blocking and antihypertensive activities. In addition, the possible correlations between the blocking and antihypertensive activities are also briefly discussed.

Bioorganic & Medicinal Chemistry published new progress about 4230-93-7. 4230-93-7 belongs to catalysis-chemistry, auxiliary class Alkenyl,Nitro Compound,Benzene,Ether, name is 1,2-Dimethoxy-4-(2-nitrovinyl)benzene, and the molecular formula is C20H23N3O2S, Synthetic Route of 4230-93-7.

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

Lin, Jiahui published the artcileEarly secreted antigenic target of 6-kDa of Mycobacterium tuberculosis induces transition of macrophages into epithelioid macrophages by downregulating iNOS/NO-mediated H3K27 trimethylation in macrophages, Category: catalysis-chemistry, the publication is Molecular Immunology (2020), 189-200, database is CAplus and MEDLINE.

Tuberculosis (TB) is a chronic infectious disease caused by Mycobacterium tuberculosis (Mtb). Granuloma is a pathol. feature of tuberculosis and is a tight immune cell aggregation caused by Mtb. The main constituent cells are macrophages and their derivative cells including epithelioid macrophages. However, the mol. mechanism of the transition has not been reported. The purpose of this study was to investigate whether early secreted antigenic target of 6-kDa (ESAT6) can induce the transition of bone marrow-derived macrophages (BMDMs) into epithelioid macrophages and its possible mol. mechanism. The recombinant ESAT6 protein was obtained from E.coli carrying esat6 gene after iso-Pr ¦Â-D-thiogalactopyranoside (IPTG) induction. BMDMs were isolated from bone marrow of mice hind legs. Cells viability was detected by Cell Counting Kit 8 (CCK8) assays. The expression levels of mRNA and proteins were detected by qPCR and Western blot, or evaluated by flow cytometry. The expression level of nitric oxide (NO) was measured with a nitric oxide indicator. ESAT6 could significantly induce mRNA and protein expression levels of a group of epithelioid macrophages marker mols. (EMMMs), including E-cadherin, junction plakoglobin, ZO1, desmoplakin, desmoglein 3 and catenin porteins, in BMDMs. These events could be abrogated in macrophage from TLR2 deficiency mice. ESAT6 could also markedly induce iNOS/NO production that could significantly inhibit trimethylation of H3K27 in the cells. ESAT6-induced expressions of epithelioid macrophages marker mols. were significantly inhibited in the presence of H3K27 histone demethylase inhibitor GSK J1. Furthermore, ROS scavenging agent N,N’-Dimethylthiourea (DMTU) could markedly inhibit the transition induced by ESAT6 in macrophages. This study demonstrates that ESAT6 bound with TLR2 can activate iNOS/NO and ROS signalings to reduce the trimethylation of H3K27 resulting in the increment of EMMMs expression that is beneficial to the transition of macrophages into epithelioid macrophages. However, hypoxia can inhibit this transition event. This study has provided new evidence of pathogenesis of granuloma caused by Mtb and also proposed new ideas for the treatment of TB.

Molecular Immunology 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, Category: catalysis-chemistry.

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

Jiang, Hejin published the artcileSymmetry Breaking and Amplification in a Self-Assembled Helix from Achiral trans-3-Nitrocinnamic Acid, Safety of (E)-3-(3-Nitrophenyl)acrylic acid, the publication is Journal of Physical Chemistry C (2018), 122(23), 12559-12565, database is CAplus.

Understanding the process of chiral symmetry breaking, amplification, and transfer to the macroscopic chirality in self-assembled systems has been a subject of essential challenge and immense interest. Here, we show that a simple trans-3-nitrocinnamic acid (3-NCA) self-assembles into a helix in solution with symmetry breaking. Upon casting on a solid substrate, the tiny chiral bias in solution was amplified into macroscopic chirality, which could be detected via CD measurements. Furthermore, the SEM observation revealed the unequal numbers of left- and right-handed helixes, which accounted for the net supramol. chirality. In comparison with the other isomers or related mols., it was found that only 3-NCA showed symmetry breaking. It was revealed that the H-bond and dipole-dipole interaction were responsible for the spontaneous symmetry breaking. This work provides a further insight into the emergence and amplification of supramol. chirality in self-assembly systems from achiral mols.

Journal of Physical Chemistry C published new progress about 1772-76-5. 1772-76-5 belongs to catalysis-chemistry, auxiliary class Benzenes, name is (E)-3-(3-Nitrophenyl)acrylic acid, and the molecular formula is C9H7NO4, Safety of (E)-3-(3-Nitrophenyl)acrylic acid.

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