Month: November 2022

Wang, Ziwei published the artcileEstimating the deposition of polycyclic aromatic hydrocarbons in human airways: The role of particle size, Category: catalysis-chemistry, the publication is Atmospheric Pollution Research (2022), 13(7), 101461, database is CAplus.

Most previous studies used atm. concentrations of polycyclic aromatic hydrocarbons (PAHs) to estimate the risk of exposure via inhalation, but neglected the disparities in the effects of particle size. In this study, an extensive literature search retrieved data from 35 cities on atm. PAHs and particle size distributions, and a multiple-path particle dosimetry model was used to simulate the PAH deposition in human airways. The results revealed that the median concentration of total PAHs was 38 (range, 0.6-2074.2) ng/m³, while the median concentration of benzo(a)pyrene equivalent (B[a]Peq) was 11 ng/m³. Together with exposure to congener-specific PAHs, the median deposited concentrations of total PAHs or B[a]Peq were the highest in particulate matter (PM) with diameters of 1-2.5 ¦Ìm, followed by > 1 ¦Ìm and coarse PM, which can be explained by the general increase in proportions of high mol. weight PAHs with decreasing PM size. While the deposited PAHs were dominated by 3-5 rings PAHs, the deposited B[a]Peq was concentrated in 5-ring. Moreover, although differences in the contributions of the ring number between deposited and ambient PAHs were negligible, the contributions of fine PM were 11.9% and 9.5% greater for deposited PAHs and B[a]Peq, resp. These results indicate that the risk of exposure to PAHs attached to fine PM is underestimated previously.

Atmospheric Pollution Research 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 C6H12Br2, Category: catalysis-chemistry.

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

Guo, Yanxia published the artcileEffect of Hydrogen-Consuming Compounds on In Vitro Ruminal Fermentation, Fatty Acids Profile, and Microbial Community in Water Buffalo, Quality Control of 6217-54-5, the publication is Current Microbiology (2022), 79(8), 220, database is CAplus and MEDLINE.

The present study aimed to investigate the effect of hydrogen-consuming compounds on ruminal methane (CH4) production, in vitro fermentation parameters, fatty acids profile, and microbial community in water buffalo. Different sodium nitrate to disodium fumarate ratios [2:1 (F), 1:1 (S), 1:2 (T)] were studied in vitro by batch culture technique in the presence of linoleic acid. Results revealed that the dominant bacterial communities were not affected with sodium nitrate and disodium fumarate, whereas CH4 production and Verrucomicrobia, Succiniclasticum, norank_f__Muribaculaceae, and Prevotellaceae_UCG-003 were reduced (P < 0.05). However, ruminal pH, unsaturated fatty acids/saturated fatty acids (UFA/SFA) and Campilobacterota, Selenomonas, Succinivibrio, Oribacterium, Christensenellaceae_R-7_group, Campylobacter, Shuttleworthia, Schwartzia, and Prevotellaceae_YAB2003_group were increased (P < 0.05). Total volatile fatty acids (TVFA) and Spirochaetae, Fibrobacterota, Verrucomicrobia, Fibrobacter, Treponema, and Prevotellaceae were decreased in F (P < 0.05), but cis-9, trans-11CLA, acetate/propionate and Proteobacteria, Campilobacterota, Selenomonas, Succinivibrio, and Campylobacter were increased in F (P < 0.05). The highly selected bacterial genera in F were Campylobacter and Succinivibrio. The disodium fumarate, enhanced (P < 0.05) the TVFA, propionate, total bacteria, Butyrivibrio proteoclasticus, and Atypical butyrivibrio. The concentrations of C18:3n3, C20:3n6, C21:0, C22:2n6, and C22:1n9, as well as the populations of total fungi, protozoa, methanogens, Butyrivibrio hungatei in T were higher (P < 0.05). The highly selected bacterial genera in T were Fibrobacter and Treponema. Conclusively, the addition of sodium nitrate and disodium fumarate can reduce the CH4 production and optimize ruminal fatty acid composition Furthermore, disodium fumarate can alleviate the adverse effect of sodium nitrate on the rumen fermentation

Current Microbiology 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, Quality Control of 6217-54-5.

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

Seo, Jeong Moo published the artcileAn expeditious entry to rare tetrahydroimidazo[1,5-c]pyrrolo[1,2-a]pyrimidin-7(8H)-ones: A single-step gateway synthesis of glochidine congeners, Recommanded Product: 3-Benzoylpropionicacid, the publication is Tetrahedron (2019), 75(51), 130760pp., database is CAplus.

A single-step gateway synthesis of glochidine and its congeners that possessed the rare uncommon tetrahydroimidazo[1,5-c]pyrrolo[1,2-a]pyrimidine core I [R¹ = Me, (CH₂)₄CH₃, 4-MeC₆H₄, etc.; R² = R³ = H, Me] was developed employing histamine and readily available ¦Ã-ketoesters. Key features of the developed reaction involved tandem three C-N bonds formation and concomitant annulation of two rings in one pot to access this unique and complex tricyclic structure. Exploration of the unknown bioactivity of these compounds revealed that they elicit antiproliferative activity comparable to the anticancer drug imatinib against 6 cancer cell lines.

Tetrahedron 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 C9H8BrF3, Recommanded Product: 3-Benzoylpropionicacid.

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

Shiina, Isamu published the artcileEnantioselective total synthesis of Octalactin A using asymmetric aldol reactions and a rapid lactonization to form a medium-sized ring, Synthetic Route of 19117-31-8, the publication is Chemistry – A European Journal (2005), 11(22), 6601-6608, database is CAplus and MEDLINE.

Octalactin A (I), an antitumor agent (no data) containing an eight-membered lactone moiety, has been stereoselectively prepared by means of enantioselective aldol reactions of selected silyl enolates with achiral aldehydes, promoted by a chiral Sn^II complex. The medium-sized lactone part was effectively constructed by way of a new and rapid mixed-anhydride lactonization using 2-methyl-6-nitrobenzoic anhydride (MNBA) with a catalytic amount of 4-(dimethylamino)pyridine (DMAP) or 4-(dimethylamino)pyridine 1-oxide (DMAPO). The use of only 5 mol % of DMAP or 2 mol % of DMAPO rapidly promoted formation of the medium-sized ring of the octalactin, demonstrating the remarkable efficiency of the new lactonization protocol.

Chemistry – A European Journal published new progress about 19117-31-8. 19117-31-8 belongs to catalysis-chemistry, auxiliary class Oxidant, name is N-(tert-Butyl)-S-phenylthiohydroxylamine, and the molecular formula is C6H10O7, Synthetic Route of 19117-31-8.

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

Tanaka, Toru published the artcileSynthesis of Double-Decker Silsesquioxanes from Substituted Difluorosilane, Name: Difluorodiphenylsilane, the publication is Organometallics (2019), 38(4), 743-747, database is CAplus.

A novel synthetic method for the construction of a double-decker silsesquioxane from fluorosilanes was developed. Phenyl-substituted double-decker silsesquioxane was prepared under mild conditions by coupling difluorodiphenylsilane and a tetrasiloxanolate precursor. A similar reaction was performed using difluorovinylsilane, and a divinyl double-decker silsesquioxane was obtained. The one-step reaction of a functional difluorosilane containing an aminopropyl group afforded a novel double-decker silsesquioxane with two amino groups complexed with BF₃, which can react with carboxylic acid anhydrides to afford an amide product. This synthetic method using difluorosilane is tolerant of a wide range of functional groups and is applicable to the synthesis of polycyclic silsesquioxanes bearing amino groups, which are difficult to directly obtain from dichlorosilane.

Organometallics published new progress about 312-40-3. 312-40-3 belongs to catalysis-chemistry, auxiliary class Organic Silicones, name is Difluorodiphenylsilane, and the molecular formula is C15H21BO3, Name: Difluorodiphenylsilane.

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

Lu, Youmei published the artcileHighly efficient two-photon initiated polymerization in solvent by using a novel two-photon chromophore and co-initiators, Safety of 2,6-Diisopropyl-N,N-dimethylaniline, the publication is Journal of Materials Chemistry (2004), 14(9), 1391-1395, database is CAplus.

Highly efficient two-photon initiated polymerization (TPIP) of acrylate monomer in dioxane solution was carried out using three-component photoinitiator system containing a novel D-¦Ð-A-¦Ð-D type chromophore I (Ia; R = Bu₂N, Ib; R = Et₂N), the co-initiator 6-diisopropyl-N,N-dimethylaniline (DDA) and diphenyliodonium salt, Ph₂I⁺PF₆^–(PIP). The authors measured the quasi two-photon polymerization rates (R_p) based on scanning speed and the width of the written protruding line. Polymerization rates of in the presence of chromophore Ia and Ib were 113 ¦Ìm³ s^-1 and 157 ¦Ìm³ s^-1 in the case of the laser power 4.5 mW at 820 nm (pulse width: 85 fs, repetition rate 82 MHz ) resp. In order to estimate the mechanism of the photochem. reaction, the change of UV absorption of the three-component system, T-T transient absorption and the cyclic voltammetry (CV) of the novel chromophores were measured. The authors concluded that highly efficient electron transfer between DDA and the chromophore contributed to the long-lived radical cations of the chromophore. As a result, the generation of both DDA radicals and Ph radicals was ascribed to high sensitivity in TPIP.

Journal of Materials Chemistry published new progress about 2909-77-5. 2909-77-5 belongs to catalysis-chemistry, auxiliary class Amine,Benzene, name is 2,6-Diisopropyl-N,N-dimethylaniline, and the molecular formula is C14H23N, Safety of 2,6-Diisopropyl-N,N-dimethylaniline.

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

Harutyunyan, G. L. published the artcileSynthesis of Dihydrochlorides of Azaadamantanes Containing 8-Hydroxyquinoline Fragments and their Antibacterial Activity in Mice with Dysentery and Staphylococcal Infections, Product Details of C7H14N4, the publication is Pharmaceutical Chemistry Journal (2021), 54(12), 1205-1208, database is CAplus.

New azaadamantane derivatives containing 8-hydroxyquinoline fragments were synthesized. Their antibacterial activity was studied. The synthesized compounds exhibited high antibacterial activity in vitro. The 6-oxo-5,7-diethyl- and 5,7-dimethyl-2-(8′-hydroxyquinolyl-5′)-1,3-diazaadamantane dihydrochlorides showed therapeutic effects in mice with dysentery and staphylococcal infections.

Pharmaceutical Chemistry Journal published new progress about 14707-75-6. 14707-75-6 belongs to catalysis-chemistry, auxiliary class Triazinanes, name is 1,3,5-Triazaadamantan-7-amine, and the molecular formula is C7H14N4, Product Details of C7H14N4.

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

Dodbiba, G. published the artcileCombination of sink-float separation and flotation technique for purification of shredded PET-bottle from PE or PP flakes, COA of Formula: C14H31NO2, the publication is International Journal of Mineral Processing (2002), 65(1), 11-29, database is CAplus.

In this contribution, the separation of poly(ethylene terephthalate) (PET)-polyethylene (PE) and PET-polypropylene (PP) mixtures was studied in order to improve the grade of the raw input used in PET bottle recycling. First, PET bottles and their caps (made of PE or PP) were shredded and the floatability of each polymer was tested. Even with the addition of the wetting reagents, dodecylamine acetate (DAA) or poly(vinyl alc.) (PVA), the results did not suggest that the required 99.995% purity of PET plastic could not be achieved by flotation. Second, the mixtures were separated with a sink-float process using a drum separator. Finally, as the required purity of PET could not be obtained by either technique alone, a system utilizing a combination of the two processes was developed. This system easily achieved the desired PET grade. At last, some sink-float experiments were performed with a medium of magnesium sulfate (dense medium separation).

International Journal of Mineral Processing published new progress about 2016-56-0. 2016-56-0 belongs to catalysis-chemistry, auxiliary class Active Esterification, name is Dodecylamineacetate, and the molecular formula is C14H31NO2, COA of Formula: C14H31NO2.

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

Brusoe, Andrew T. published the artcilePalladium-Catalyzed Arylation of Fluoroalkylamines, Recommanded Product: 1,1,1-Trifluoropropan-2-amine, the publication is Journal of the American Chemical Society (2015), 137(26), 8460-8468, database is CAplus and MEDLINE.

We report the synthesis of fluorinated anilines by palladium-catalyzed coupling of fluoroalkylamines with aryl bromides and aryl chlorides. The products of these reactions are valuable because anilines typically require the presence of an electron-withdrawing substituent on nitrogen to suppress aerobic or metabolic oxidation, and the fluoroalkyl groups have steric properties and polarity distinct from those of more common electron-withdrawing amide and sulfonamide units. The fluoroalkylaniline products are unstable under typical conditions for C-N coupling reactions (heat and strong base). However, the reactions conducted with the weaker base KOPh, which has rarely been used in cross-coupling to form C-N bonds, occurred in high yields in the presence of a catalyst derived from com. available AdBippyPhos and [Pd(allyl)Cl]₂. Under these conditions, the reactions occur with low catalyst loadings (<0.50 mol % for most substrates) and tolerate the presence of various functional groups that react with the strong bases that are typically used in Pd-catalyzed C-N cross-coupling reactions of aryl halides. The resting state of the catalyst is the phenoxide complex, [BippyPhosPd(Ar)OPh]; due to the electron-withdrawing property of the fluoroalkyl substituent, the turnover-limiting step of the reaction is reductive elimination to form the C-N bond.

Journal of the American Chemical Society published new progress about 421-49-8. 421-49-8 belongs to catalysis-chemistry, auxiliary class Trifluoromethyl,Fluoride,Amine,Aliphatic hydrocarbon chain, name is 1,1,1-Trifluoropropan-2-amine, and the molecular formula is C3H6F3N, Recommanded Product: 1,1,1-Trifluoropropan-2-amine.

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

Rudolph, Martin published the artcileSpecific surface free energy component distributions and flotabilities of mineral microparticles in flotation-An inverse gas chromatography study, Category: catalysis-chemistry, the publication is Colloids and Surfaces, A: Physicochemical and Engineering Aspects (2017), 380-388, database is CAplus.

In fundamental flotation studies often the contact angle with water is used to describe wettability of a mineral surface and it is correlated with flotability. A more fundamental parameter however is the sp. surface free energy related to the contact angle via Young’s equation. Inverse gas chromatog. (iGC) has recently been proven to be a suitable method to determine sp. surface free energy components and their distributions of particulate surfaces. In this study the pure minerals quartz (SiO₂), fluoro-apatite (Ca₅[F,(PO4)₃]), and magnetite (Fe₃O₄) are examined for flotabilities and surface energy component distributions considering different methods of sample treatment and the effect of the collectors sodium oleate and dodecyl ammonium acetate. The parameter of specific net free energy of interaction between bubbles and particles immersed in water ¦¤G_pwb resulting from the complex surface energy analyses is introduced and used to evaluate the hydrophobicity of the mineral surface in correlation to microflotation recoveries. The results lead to the hypothesis that only small fractions of the surface and their change of wettability by flotation reagent adsorption will inherently define the flotability of minerals. Consequently, the main purpose of the amphiphilic collector mols. seems to be the reduction of high sp. surface free energies of small fractions of the surface that lead to a strong attraction between particle surface sites and water mols. rather than the hydrophobization of the entire mineral surface, a new paradigm in flotation science.

Colloids and Surfaces, A: Physicochemical and Engineering Aspects published new progress about 2016-56-0. 2016-56-0 belongs to catalysis-chemistry, auxiliary class Active Esterification, name is Dodecylamineacetate, and the molecular formula is C14H31NO2, Category: catalysis-chemistry.

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