Catalysis-chemistry

Masuya, Takahiro published the artcilePinpoint Dual Chemical Cross-Linking Explores the Structural Dynamics of the Ubiquinone Reaction Site in Mitochondrial Complex I, Recommanded Product: Dbco-maleimide, the publication is Biochemistry (2021), 60(10), 813-824, database is CAplus and MEDLINE.

The ubiquinone reduction step in NADH-ubiquinone oxidoreductase (complex I) is the key to triggering proton translocation in its membrane part. Although the existence of a long and narrow quinone-access channel was identified, it remains debatable whether the channel model can account for binding of various ligands (ubiquinones and inhibitors) to the enzyme. The authors previously proposed that the matrix-side interfacial region of the 49 kDa, ND1, PSST, and 39 kDa subunits, which is covered by a loop connecting transmembrane helixes (TMHs) 1 and 2 of ND3, may be the area for entry of some bulky ligands into the quinone reaction cavity. However, this proposition lacks direct evidence that the cavity is accessible from the putative matrix-side region, which allows ligands to pass. To address this, the authors examined whether Cys³⁹ of ND3 and Asp¹⁶⁰ of 49 kDa can be specifically crosslinked by bifunctional crosslinkers (tetrazine-maleimide hybrid, named TMBC). On the basis of the structural models of complex I, such dual crosslinking is unexpected because ND3 Cys³⁹ and 49 kDa Asp¹⁶⁰ are located on the TMH1-2 loop and deep inside the channel, resp., and hence, they are phys. separated by peptide chains forming the channel wall. However, three TMBCs with different spacer lengths did crosslink the two residues, giving new crosslinked ND3/49 kDa subunits. Chem. modification of either ND3 Cys³⁹ or 49 kDa Asp¹⁶⁰ blocked the dual crosslinking, ensuring the specificity of the crosslinking. Altogether, this study provides direct evidence that the quinone reaction cavity is indeed accessible from the proposed matrix-side region covered by the ND3 TMH1-2 loop.

Biochemistry published new progress about 1395786-30-7. 1395786-30-7 belongs to catalysis-chemistry, auxiliary class Inhibitor, name is Dbco-maleimide, and the molecular formula is C25H21N3O4, Recommanded Product: Dbco-maleimide.

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

Yoshimura, Tomoyuki published the artcileDevelopment of nitrolactonization mediated by iron(III) nitrate nonahydrate, Formula: C10H10O3, the publication is Chemical & Pharmaceutical Bulletin (2020), 68(12), 1220-1225, database is CAplus and MEDLINE.

The nitrolactonization of alkenyl carboxylic acids mediated by Fe(NO₃)₃¡¤9H₂O was developed. Nitrolactones I [R = H, OMe, NO₂, CN] and II [R¹ = H, Br, Me, OMe] were obtained in up to 93% yield by treatment of alkenyl carboxylic acids with Fe(NO₃)₃¡¤9H₂O. Mechanistic studies disclosed that the reaction proceeded through a radical intermediate generated from addition of NO₂ to alkenyl carboxylic acids.

Chemical & Pharmaceutical Bulletin published new progress about 2051-95-8. 2051-95-8 belongs to catalysis-chemistry, auxiliary class Carboxylic acid,Benzene,Ketone, name is 3-Benzoylpropionicacid, and the molecular formula is C3H5BN2O2, Formula: C10H10O3.

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

Ikeda, Yoshihiko published the artcileStereoselective synthesis of (Z)- and (E)-1,3-alkadienes from aldehydes using organotitanium and lithium reagents, Recommanded Product: Allyldiphenylphosphine oxide, the publication is Tetrahedron (1987), 43(4), 723-30, database is CAplus.

[3-(Diphenylphosphino)allyl]titanium reagent generated easily from allyldiphenylphosphine (I) condenses with aldehydes to give (Z)-1,3-alkadienes in high regio- and stereoselectivity. In contrast, lithiated I oxide condenses with aldehydes to give (E)-1,3–alkadienes directly and stereoselectively in good yields. Similarly, lithiated (1-buten-3-yl)diphenylphosphine oxide condenses with aldehydes to give (E)-3-methyl-1,3-alkadienes.

Tetrahedron published new progress about 4141-48-4. 4141-48-4 belongs to catalysis-chemistry, auxiliary class Aryl phosphine ligand,Mono-phosphine Ligands, name is Allyldiphenylphosphine oxide, and the molecular formula is C15H15OP, Recommanded Product: Allyldiphenylphosphine oxide.

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

Hira, Kenichiro published the artcileAssociation of blood eicosapentaenoic acid levels with intracerebral hemorrhage during the COVID-19 pandemic: preliminary experience from a single-center in Japan, HPLC of Formula: 6217-54-5, the publication is BMC Neurology (2022), 22(1), 128, database is CAplus and MEDLINE.

The COVID-19 pandemic has forced lockdowns and declarations of states of emergency, resulting in marked changes to daily life such as dietary habits in many countries. Though serum omega-3 polyunsaturated fatty acids levels have been shown to be useful markers for recurrent vascular events or worse prognosis in cardiovascular diseases and ischemic stroke, the relationship between serum omega-3 PUFA levels and the occurrence of intracerebral hemorrhage has essentially been unknown. We explored the association of serum omega-3 polyunsaturated fatty acids with intracerebral hemorrhage during the COVID-19 pandemic. Participants comprised patients admitted to Juntendo University Hospital (Tokyo, Japan) with intracerebral hemorrhage between Jan. 1, 2016 and Apr. 30, 2020. Clin. characteristics including serum omega-3 polyunsaturated fatty acid levels were compared between patients developing intracerebral hemorrhage during the period from Jan. 1, 2016 to Feb. 29, 2020, and the subsequent COVID-19 pandemic period (March 1 to Apr. 30, 2020). Clin. characteristics independently related to intracerebral hemorrhage during the COVID-19 pandemic were analyzed by comparing these two cohorts of intracerebral hemorrhage patients in different periods. A total of 103 patients (age, 67.0 ¡À 13.9 years; 67 males) with intracerebral hemorrhage were enrolled. Intracerebral hemorrhage developed in 91 patients before and 12 patients during the COVID-19 pandemic. Monthly averages of intracerebral hemorrhage patients admitted to our hospital during and before the COVID-19 pandemic were 6 and 1.82, resp. Serum eicosapentaenoic acid levels were significantly lower in intracerebral hemorrhage patients during the COVID-19 pandemic than before (31.87 ¡À 12.93¦Ìg/mL vs. 63.74 ¡À 43.29¦Ìg/mL, p = 0.007). Multiple logistic regression anal. showed that, compared to before the COVID-19 pandemic, dyslipidemia (odds ratio 0.163, 95% confidence interval 0.031-0.852; p = 0.032) and eicosapentaenoic acid levels (odds ratio 0.947, 95% confidence interval 0.901-0.994; p = 0.029) were associated with intracerebral hemorrhage during the COVID-19 pandemic. From our preliminary results, low eicosapentaenoic acid levels were linked with intracerebral hemorrhage during the COVID-19 pandemic. Low levels of eicosapentaenoic acid might be an endogenous surrogate marker for intracerebral hemorrhage during the COVID-19 pandemic.

BMC Neurology 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, HPLC of Formula: 6217-54-5.

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

Nakai, Satoru published the artcileAerobic Oxygenation of Alkylarenes over Ultrafine Transition-Metal-Containing Manganese-Based Oxides, Name: Bis(4-fluorophenyl)methane, the publication is ChemCatChem (2018), 10(5), 1096-1106, database is CAplus.

An efficient alkylarene oxygenation process catalyzed by ultrafine transition-metal-containing Mn-based oxides with spinel or spinel-like structures (M-MnO_x, M = Fe, Co, Ni, Cu) for the synthesis of aryl ketones was developed. These M-MnO_x catalysts were prepared by a low-temperature reduction method in 2-propanol-based solutions using tetra-Bu ammonium permanganate (TBAMnO₄) as the Mn source, and they exhibited high Brunauer-Emmett-Teller surface areas (typically >400 m² g^-1). Using fluorene as the model substrate, the catalytic activities of M-MnO_x and Mn₃O₄ were compared. The catalytic activities of M-MnO_x were significantly higher than that of Mn₃O₄, thus indicating that the incorporation of transition metals in manganese oxide was critical Among the series of M-MnO_x catalysts examined, Ni-MnO_x exhibited the highest catalytic activity for the oxygenation. In addition, the catalytic activity of Ni-MnO_x was higher than that of a phys. mixture of Mn₃O₄ and NiO. Furthermore, Ni-MnO_x exhibited a broad substrate scope with respect to various types of structurally diverse (hetero)alkylarenes (16 examples). The observed catalysis was truly heterogeneous, and the Ni-MnO_x catalyst was reusable for the oxygenation of fluorene at least three times and its high catalytic performance was preserved, for example, the reaction rate, final product yield, and product selectivity. The present Ni-MnO_x-catalyzed oxygenation process is possibly initiated by a single-electron oxidation process, and herein a plausible oxygen-transfer mechanism is proposed based on several pieces of exptl. evidence.

ChemCatChem published new progress about 457-68-1. 457-68-1 belongs to catalysis-chemistry, auxiliary class Fluoride,Benzene, name is Bis(4-fluorophenyl)methane, and the molecular formula is C13H10F2, Name: Bis(4-fluorophenyl)methane.

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

Dohi, Toshifumi published the artcileSelective carboxylation of reactive benzylic C-H bonds by a hypervalent iodine(III)/inorganic bromide oxidation system, Application In Synthesis of 457-68-1, the publication is Beilstein Journal of Organic Chemistry (2018), 1087-1094, database is CAplus and MEDLINE.

An oxidation system comprising phenyliodine(III) diacetate (PIDA) and iodosobenzene with sodium bromide in DCM led to the direct introduction of carboxylic acids into benzylic C-H bonds, for the formation corresponding esters e.g. I under mild conditions. The unique radical species, generated by the homolytic cleavage of the labile I(III)-Br bond of the in situ-formed bromo-¦«³-iodane, initiated benzylic carboxylation with a high degree of selectivity for the secondary benzylic position.

Beilstein Journal of Organic Chemistry published new progress about 457-68-1. 457-68-1 belongs to catalysis-chemistry, auxiliary class Fluoride,Benzene, name is Bis(4-fluorophenyl)methane, and the molecular formula is C13H10F2, Application In Synthesis of 457-68-1.

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

Nakamura, Shinji published the artcileRegio- and Chemoselective Silylmetalation of Functionalized Terminal Alkenes, Quality Control of 4141-48-4, the publication is Journal of the American Chemical Society (2007), 129(1), 28-29, database is CAplus and MEDLINE.

A regio-/chemoselective silylmetalation of various functionalized alkenes, e.g. I, based on the zinc silyl complex in the presence of a catalytic amount of copper cyanide was developed. Silylmetalation of alkenes, followed by electrophilic trapping, proved to be a powerful tool for the functionalization of the continuous carbon atoms of the alkenes. The resultant alkylsilanes, e.g. II, can be converted smoothly into alcs., e.g. III, by oxidative cleavage of the carbon-silicon bond.

Journal of the American Chemical Society published new progress about 4141-48-4. 4141-48-4 belongs to catalysis-chemistry, auxiliary class Aryl phosphine ligand,Mono-phosphine Ligands, name is Allyldiphenylphosphine oxide, and the molecular formula is C15H15OP, Quality Control of 4141-48-4.

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

Shukuri, Miho published the artcileEx vivo imaging and analysis of ROS generation correlated with microglial activation in rat model with acute neuroinflammation induced by intrastriatal injection of LPS, Application In Synthesis of 6972-05-0, the publication is Biochemical and Biophysical Research Communications (2021), 101-106, database is CAplus and MEDLINE.

Neuroinflammation and oxidative stress are hallmarks of neurodegenerative diseases. Microglia, the major important regulators of neuroinflammation, are activated in response to excessive generation of reactive oxygen species (ROS) from damaged cells and resulting in elevated and sustained damages. However, the relationship between microglia and ROS-regulatory system in the early stages of neuroinflammation prior to the appearance of neuronal damages have not been elucidated in detail. In this study, we analyzed the time-dependent changes in ROS generation during acute neuroinflammation in rats that were given an intrastriatal injection of lipopolysaccharide (LPS). We evaluated the effects of minocycline, an anti-inflammatory antibiotic, and N,N-dimethylthiourea (DMTU), a radical scavenger, to understand the correlation between activated microglia and ROS generation. Ex vivo fluorescence imaging using dihydroethidium (DHE) clearly demonstrated an increased ROS level in the infused side of striatum in the rats treated with LPS. The level of ROS was changed in time-dependent manner, and the highest level of ROS was observed on day 3 after the infusion of LPS. Immunohistochem. studies revealed that time-dependent changes in ROS generation were well correlated to the presence of activated microglia. The inhibition of microglial activation by minocycline remarkably reduced ROS levels in the LPS-injected striatum, which indicated that the increased ROS generation caused by LPS was induced by activated microglia. DMTU decreased ROS generation and resulted in remarkable inhibitory effect on microglial activation. This study demonstrated that ROS generation during acute neuroinflammation induced by LPS was considerably associated with microglial activation, in an intact rat brain. The results provides a basis for understanding the interaction of ROS-regulatory system and activated microglia during neuroinflammation underlying neurodegenerative diseases.

Biochemical and Biophysical Research Communications 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 C7H16Cl2Si, Application In Synthesis of 6972-05-0.

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

Acar, Tayfun published the artcileAngiotensin(1-7)-stearic acid conjugate: synthesis and characterization, Name: Fmoc-Pro-OH, the publication is Journal of the Turkish Chemical Society, Section A: Chemistry (2022), 9(2), 331-338, database is CAplus.

The novel coronavirus, SARS-CoV-2, broken out as the COVID-19 epidemic, is transported into the cytoplasm by angiotensin-converting enzyme-2 (ACE2), a key protein of the renin-angiotensin-system (RAS). ACE2 is a protective protein that reduces angiotensin (Ang) II, the bioactive component of RAS, by converting it to its potent antagonist, Ang-(1-7) peptide, in order to provide a pathophysiol. response to stimuli. Although ACE-2 is upregulated especially in pulmonary endothelial cells and alveolar epithelial cells, downregulation of ACE-2 in the lung owing to loss of key regulatory factors explains the enzyme-dependent lethality of SARS-CoV-2. The N-terminal domain (NTD) of S1, one of the protein subunits of coronaviruses, is known to recognize acetylated sialic acids on glycosylated cell surface receptors. In this study, the stearic acid-peptide conjugate mimicking the sialic acid structure was synthesized, which will be able to balance uncontrolled inflammatory response and excessive cytokine production, and depending on these to suppress pneumonia and acute respiratory distress syndrome (ARDS), against SARS-CoV-2. It was expected that fatty acid acylation would greatly enhance cellular internalization and cytosolic distribution of the peptide through the cell membrane. Thus, we synthesized fatty acyl derivative of the N-Ac-Gly4-Ang (1-7) peptide. The peptide was synthesized using Fmoc/tBu solid-phase peptide chem. and characterized by FT-IR, Zetasizer, and LC-ESI-MS. This study provided more detailed insights into understanding and meeting the basic structural requirements for optimal cellular delivery and formulation of the stearyl Ang (1-7)-peptide conjugate.

Journal of the Turkish Chemical Society, Section A: 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, Name: Fmoc-Pro-OH.

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

Hegemann, Corinna published the artcileSynthetic and Structural Investigations on the Reactivity of the Cd-I Bond in [ICd{Zr₂(OPrⁱ)₉}] to Construct New Mixed-Metal Alkoxides, COA of Formula: C9H9F5Si, the publication is Organometallics (2013), 32(6), 1654-1664, database is CAplus.

New mixed-metal alkoxides [XCd{Zr₂(OPrⁱ)₉}]_n (X = -C₂F₅, -C₆F₅, -C₆F₄-4-H, -NO₃, -NCO, -SO₃CF₃, -O₂CCF₃, -O₂CC₂F₅, -O₂CCH₃, -ClO₄, -CN, -SO₄; n = 1, 2) were obtained by the scission of the Cd-I bond in the iodo heterobimetallic isopropoxide [ICd{Zr₂(OPrⁱ)₉}] (1), whereby the underlying synthetic strategies involve metathesis reactions with Ag salts or Lewis acid-base interactions between the Bronsted acid [Zr(OPrⁱ)₄(HOPrⁱ)]₂ and bis(fluoroorgano)cadmium (Cd(R_f)₂) compounds The new compounds were characterized by multinuclear NMR spectroscopy, elemental anal., and mass spectrometry. The results of x-ray diffraction anal. of [(F₅C₆)Cd{Zr₂(OPrⁱ)₉}] (2), [(4-H-F₄C₆)Cd{Zr₂(OPrⁱ)₉}] (3), [(F₅C₂)Cd{Zr₂(OPrⁱ)₉}]₂ (4), [(ONO₂)Cd{Zr₂(OPrⁱ)₉}]₂ (5), [(CH₃CO₂)Cd{Zr₂(OPrⁱ)₉}] (6), [(O₂ClO₂)(H₅C₃N)Cd{Zr₂(OPrⁱ)₉}] (7), [(¦Ì-O₂ClO₂)Cd{Zr₂(OPrⁱ)₉}]₂ (8), [(¦Ì-O₂CCF₃)Cd{Zr₂(OPrⁱ)₈(O₂CCF₃)}]₂ (9), [(¦Ì-O₂CC₂F₅)Cd{Zr₂(OPrⁱ)₈(O₂CC₂F₅)}]₂ (10), [(¦Ì(O,N)-OCN)Cd{Zr₂(OPrⁱ)₉}]₂ (11), and [(¦Ì-O₂SOCF₃)Cd{Zr₂(OPrⁱ)₉}]₂ (12) revealed the mol. framework to be formally constituted by tetradentate coordination of a nonaisopropoxo dizirconate unit, {Zr₂(OPrⁱ)₉}^–, to a CdX⁺ unit. In solution and in the solid state, 1–7 exist as monomers, whereas compounds 8–12 form dimers.

Organometallics published new progress about 1206-46-8. 1206-46-8 belongs to catalysis-chemistry, auxiliary class Organic Silicones, name is Trimethyl(perfluorophenyl)silane, and the molecular formula is C9H9F5Si, COA of Formula: C9H9F5Si.

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