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1.
Edward Korshin Rimma Eliseyenkova Lapos;ubov Zakharova Layla Sabirova Yakov Levin 《Phosphorus, sulfur, and silicon and the related elements》2013,188(1-4)
Abstract In contrast to the great variety of well known phosphorus heterocycles with exocyclic C=O double bond the number of ones containing exocyclic C=N bond is unusually modest. We elaborated the convenient method of preparation of various N,P,N-heterocycles with exocyclic C=N bond (1–4) from the readily available corresponding amino acid amidines and appropriated dichlorides or diamides of phosphorus (III) acids. Rings' 1–3 with P(III) are easily converted into (thio)phosphoryl derivatives, while the direct phosphorylation of amino amidines by RP(Y)Cl2 is unusually ineffective. Tricycles 4 - derivatives of 2-(2-amino pheny1)imidazoline - mainly exist in the more conjugated hydrophosphazo tautomeric form 4b (>90 %). 相似文献
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Feng Shao Layla Panahipour Mariane Beatriz Sordi Fangrui Tang Ronghua Liu Reinhard Gruber 《Molecules (Basel, Switzerland)》2022,27(4)
Dalbergia cochinchinensis has been widely used in traditional medicine because of its flavonoids; however, the impact of the flavonoids to modulate the inflammatory response to oral cells remains to be described. For this aim, we isolated 4,7,2′-trihydroxy-4′-methoxyisoflavanol (472T4MIF) and 6,4′-dihydroxy-7-methoxyflavane (64D7MF) from the heartwood of D. cochinchinensis and confirmed the chemical structure by nuclear magnetic resonance. We show here that both flavonoids are inhibitors of an inflammatory response of murine RAW 264.7 inflammatory macrophages stimulated by LPS. This is indicated by interleukin (IL)1, IL6, and chemokine CCL2 production besides the phosphorylation of p65. Consistently, in primary murine macrophages, both flavonoids decreased the inflammatory response by lowering LPS-induced IL1 and IL6 expression. To introduce oral cells, we have used human gingival fibroblasts and provoked the inflammatory response by exposing them to IL1β and TNFα. Under these conditions, 472T4MIF, but not 64D7MF, reduced the expression of chemokines CXCL1 and CXCL2. Taken together, we identified two flavonoids that can reduce the expression of cytokines and chemokines in macrophages and fibroblastic cells. 相似文献
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The Carbon-13 chemical shifts of N-Cinamylidenehexyl, t-butyl and sixteen substituted aryl amines were analysed. The lanthanide induced carbon-13 chemical shifts of the cis and trans of four N-cinamylidene substituted anilines were analysed. The spectra N-cinamylidene hexylamine showed only the trans form. The cis/trans ratio of N-cinamylidene aryl amines increased as the LSR concentration increased. 相似文献
4.
Layla A. Al Juhaiman 《Journal of Saudi Chemical Society》2010,14(1):131-137
A method of estimating Al leaching from Al cook ware in some meat extracts and liquid milk was investigated. In the present work four kinds of Al cook wares from four countries were chosen from the local market. Extracts of boiled meat (lamb, chicken, and fish) were used to make 10–50% (w/v) concentrations. In addition liquid fresh milk and long life milk were diluted to make 10–50% (v/v) concentrations. Weight loss (WL) method, atomic absorption, polarization method, and surface study were applied. The “estimated” Al intake per person from WL in 30% meat extract and milk range from 8.16 to 12.75 mg/h with fish extract having the highest leaching and chicken extract having the lowest leaching. Atomic absorption gave comparable results to that of WL. Comparing the present results with the Provisional Tolerance Weekly Intake of Al approved by the FDA/WHO shows that Al leaching from Al cook wares may add high doses of Al into the diet. 相似文献
5.
Jussara de Araújo Gonçalves André Luis Dantas Ramos Layla L. L. Rocha Anderson Kurunczi Domingos Robson S. Monteiro José Sotolongo Peres Nelson C. Furtado Carlton A. Taft Donato A. G. Aranda 《Journal of Physical Organic Chemistry》2011,24(1):54-64
Biodiesel can be obtained from fatty acid raw materials through esterification. The reactivity of lauric, palmitic, stearic, oleic, and linoleic fatty acids with methanol using powdered niobic acid as a heterogeneous catalyst was investigated in this work, both experimentally (in a batch reactor) and theoretically. A 23 experimental design was used, with methanol/fatty acid molar ratio, catalyst concentration, and temperature as main factors. An empirical model demonstrated that temperature is the most important variable. Fourteen heterogeneous and 56 homogeneous‐like kinetic models were tested. A homogeneous‐like model considering zero order for all species and inhibition by water was the most adequate for experiments without catalyst. A homogeneous‐like model considering a second‐order reaction in relation to the fatty acid and no water inhibition was the most adequate for niobic acid catalyzed reaction. Molecular modeling confirmed the experimental results showing that the reactivity is directly related to the increase of unsaturated bonds and the reduction of carbon chain length. The polarity of the fatty acid is determinant in the reactivity. At the molecular level, reaction occurs between the HOMO orbital of methanol and LUMO orbitals of fatty acids and reactivity is higher when the energy difference between these orbitals is lower. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
6.
James A. Cox Kamila M. Wiaderek B. Layla Mehdi Benjamin P. Gudorf David Ranganathan Silvia Zamponi Mario Berrettoni 《Journal of Solid State Electrochemistry》2011,15(11-12):2409-2417
Silica sol-gel (SG) films with templated pores were deposited on glassy carbon (GC) electrodes by an electrochemically initiated process. Generation-4 poly(amidoamine), PAMAM, dendrimer was included in the tetraethoxysilane precursor to facilitate pore formation. The PAMAM adsorbs to the GC, which blocks SG formation at those sites on the electrode. The pore size was 10?±?5?nm. After removal of the PAMAM, cyclic voltammetry of Fe(CN)6 3? and Ru(NH3)6 3+ at pH?6.2 showed that the residual negative charge on the silica attenuated the current for the former and increased the current for the latter, presumably by electrostatic repulsion and ion-exchange preconcentration, respectively. This premise was supported by repeating the measurements at the isoelectric point. Methylation of the silanol sites was used to eliminate the charge of the SG. At the end-capped SG, the voltammetry of Fe(CN)6 3? and Ru(NH3)6 3+ yielded currents that were independent of pH over the range 2.1 to 7.2. Circumventing the need for the silanization by using (3-glycidyloxypropyl)trimethoxysilane as the sol-gel precursor failed because the oxygen plasma treatment to remove the PAMAM attacked the organically modified sol-gel backbone. The resulting modified electrode mitigated the influence of proteins on the voltammetry of test species and stabilized functionalize nanoparticle catalysts under hydrodynamic conditions. 相似文献
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The rate of hydrolysis of aryl phosphinothioates, the most reactive phosphinates yet studied, correlates with Hammett's σ values suggesting that formation of a pentaccordinate intermediate is the rate-determining step. 相似文献
9.
Almazroia Layla Shah Reem K. El-Metwaly Nashwa M. Farghaly Thoraya A. 《Research on Chemical Intermediates》2019,45(4):1943-1971
Research on Chemical Intermediates - A new series of metal ion complexes from a triazole-Schiff base was synthesized and fully characterized. The tridentate mode of coordination was the only mode... 相似文献
10.
Reetz MT Soni P Fernández L Gumulya Y Carballeira JD 《Chemical communications (Cambridge, England)》2010,46(45):8657-8658
Mutants of the lipase from Bacillus subtilis, previously engineered for enhanced thermostability using directed evolution based on the B-FIT method, show significantly increased tolerance to hostile organic solvents. 相似文献