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61.
Rosangela Oliva Federica Albanese Giacomo Cipriani Francesca Ridi Donatella Giomi Marino Malavolti Lorenza Bernini Antonella Salvini 《Journal of Polymer Research》2014,21(7):1-12
A new family of oligotrehaluronamides was synthesized through the polycondensation of α,α-trehaluronic acid dimethyl ester and different diamines or polyamines. In particular, diamines with different molecular structure (1,n-alkylene diamines, aromatic diamine, and alkyleneoxydiamine) were used in order to modulate the molecular weights and the physical characteristics of the products, such as Tg, hydrophilic or hydrophobic properties, and solubility. α,α-Trehaluronic acid was obtained from a renewable source as α,α-trehalose. The syntheses of oligotrehaluronamides were carried out in different solvents such as ethanol, methanol, THF and DMSO, using triethylamine as catalyst. All the compounds obtained in this study were characterized through FT-IR and NMR spectroscopy. The molecular weights were evaluated by 1H-NMR and in some cases compared with those obtained from ESI-MS spectrometry. Glass transition temperatures and melting points were detected by differential scanning calorimetry. Low molecular weight oligoamides, containing several hydroxyl groups, are water-soluble and could be used in water-based formulations. 相似文献
62.
63.
Wegard Skistad Shewangizaw Teketel Francesca Lønstad Bleken Pablo Beato Silvia Bordiga Merete Hellner Nilsen Unni Olsbye Stian Svelle Karl Petter Lillerud 《Topics in Catalysis》2014,57(1-4):143-158
Product flexibility is key to meeting fluctuating chemicals demands in the future. In this contribution, the methanol to hydrocarbons (MTH) reaction was investigated over two Ge-containing H-ITQ-13 samples, one with needle-like (H-ITQ-13(N), with (Si+Ge)/Al) = 42) and another with plate-like (H-ITQ-13(P), with (Si+Ge)/Al > 100) morphology. The samples were characterised using XRD, BET, SEM/EDS and FTIR spectroscopy, and their MTH performance was compared with the performance of H-ZSM-5 and H-ZSM-22. Similar specific surface areas (413 and 455 m2 g?1 for H-ITQ-13(N) and (P), respectively) and similar acid strength (Δν ~ ?327(?310) cm?1) was observed for the two H-ITQ-13 samples. Testing of H-ITQ-13(N) at weight hourly space velocity (WHSV) = 2–8 h?1 at 350–450 °C revealed that C5+ alkenes were the main products (35–45 % selectivity at 400 °C), followed by propene and butene. A low but significant selectivity for aromatic products was observed (6–8 % selectivity at 400 °C). Product selectivity was found to be independent of deactivation. The methanol conversion capacity of H-ITQ-13(N) was 120–150 g methanol g?1 catalyst at 400 °C. Testing H-ITQ-13 at high (30 atm) and ambient pressure, respectively, at 350 °C showed that a high pressure led to enhanced C5+ selectivity, but close to a tenfold decrease in methanol conversion capacity. H-ITQ-13(P) was tested at 400 °C and 2 h?1. It gave lower conversion than H-ITQ-13(N). Furthermore, when compared at the same conversion level, H-ITQ-13(P) gave higher C5+ alkene selectivity, lower aromatics selectivity, and a higher propene to ethene ratio than H-ITQ-13(N). The H-ITQ-13 samples yielded a product spectrum intermediate of H-ZSM-22 and H-ZSM-5. The effluent product cut-off of H-ITQ-13 was similar to that of H-ZSM-5 with tetramethylbenzene as the largest significant product, while H-ZSM-22 produced mainly linear and branched alkenes. The lifetime of H-ITQ-13(N) was clearly enhanced compared to H-ZSM-22, but inferior to H-ZSM-5. 相似文献
64.
Salvatore Mirabile Dr. Serena Vittorio Prof. Maria Paola Germanò Dr. Ilenia Adornato Dr. Laura Ielo Prof. Antonio Rapisarda Prof. Rosaria Gitto Francesca Pintus Dr. Antonella Fais Prof. Laura De Luca 《ChemMedChem》2021,16(19):3083-3093
There is a considerable attention for the development of inhibitors of tyrosinase (TYR) as therapeutic strategy for the treatment of hyperpigmentation disorders in humans. Continuing in our efforts to identify TYR inhibitors, we describe the design, synthesis and pharmacophore exploration of new small molecules structurally characterized by the presence of the 4-fluorobenzylpiperazine moiety as key pharmacophoric feature for the inhibition of TYR from Agaricus bisporus (AbTYR). Our investigations resulted in the discovery of the competitive inhibitor [4-(4-fluorobenzyl)piperazin-1-yl]-(3-chloro-2-nitro-phenyl)methanone 26 (IC50=0.18 μM) that proved to be ∼100-fold more active than reference compound kojic acid (IC50=17.76 μM). Notably, compound 26 exerted antimelanogenic effect on B16F10 cells in absence of cytotoxicity. Docking analysis suggested its binding mode into AbTYR and into modelled human TYR. 相似文献
65.
A recent note by Lu et al. presented a theoretical study of atomic friction using a two-spring Tomlinson model. In this comment,
we argue that the conclusion of the note can be understood in a simple manner, and that the discussion of the criterion for
the onset of stick-slip is unnecessarily complicated and potentially misleading. 相似文献
66.
67.
Dr. Francesca Ferlenghi Dr. Michele Mari Prof. Gabriella Gobbi Dr. Gian Marco Elisi Prof. Marco Mor Prof. Silvia Rivara Prof. Federica Vacondio Dr. Silvia Bartolucci Prof. Annalida Bedini Dr. Fabiola Fanini Prof. Gilberto Spadoni 《ChemMedChem》2021,16(19):3071-3082
The MT2-selective melatonin receptor ligand UCM765 (N-(2-((3-methoxyphenyl)(phenyl)amino)ethyl)acetamide), showed interesting sleep inducing, analgesic and anxiolytic properties in rodents, but suffers from low water solubility and modest metabolic stability. To overcome these limitations, different strategies were investigated, including modification of metabolically liable sites, introduction of hydrophilic substituents and design of more basic derivatives. Thermodynamic solubility, microsomal stability and lipophilicity of new compounds were experimentally evaluated, together with their MT1 and MT2 binding affinities. Introduction of a m-hydroxymethyl substituent on the phenyl ring of UCM765 and replacement of the replacement of the N,N-diphenyl-amino scaffold with a N-methyl-N-phenyl-amino one led to highly soluble compounds with good microsomal stability and receptor binding affinity. Docking studies into the receptor crystal structure provided a rationale for their binding affinity. Pharmacokinetic characterization in rats highlighted higher plasma concentrations for the N-methyl-N-phenyl-amino derivative, consistent with its improved microsomal stability and makes this compound worthy of consideration for further pharmacological investigation. 相似文献
68.
Filippo Fabbri Francesca Rossi Manuela Melucci Ilse Manet Giovanni Attolini Laura Favaretto Massimo Zambianchi Giancarlo Salviati 《Nanoscale research letters》2012,7(1):680
A new class of nanostructured hybrid materials is developed by direct grafting of a model thiophene-based organic dye on the surface of 3C-SiC/SiO2 core/shell nanowires. TEM-EDX analysis reveals that the carbon distribution is more spread than it would be, considering only the SiC core size, suggesting a main contribution from C of the oligothiophene framework. Further, the sulfur signal found along the treated wires is not detected in the as-grown samples. In addition, the fluorescent spectra are similar for the functionalized nanostructures and T3Pyr in solution, confirming homogeneous molecule grafting on the nanowire surface. Chemical and luminescence characterizations confirm a homogeneous functionalization of the nanowires. In particular, the fluorophore retains its optical properties after functionalization. 相似文献
69.
Andrea Ianni Denise Innosa Camillo Martino Lisa Grotta Francesca Bennato Giuseppe Martino 《Journal of dairy science》2019,102(4):2918-2927
Zinc represents an essential microelement for several biochemical mechanisms. The body's inability to store zinc necessarily requires a constant dietary supply to avoid alteration of physiological functions. The aim of the present study was to investigate the effect of dietary enrichment with zinc on chemical-nutritional and aromatic properties of milk and cheese. Thirty commercial dairy cows, balanced for parity, milk production, and days in milk, were randomly assigned to 2 groups. The control group was fed with a conventional complete diet (22 kg of dry matter/animal per day), whereas the experimental group received a daily zinc supplementation of 60 mg per kg of dry complete feed. During the experimental period, the milk yield was monitored and samples of milk and caciotta cheese were collected to obtain information about the chemical-nutritional composition and aromatic profile. Dietary zinc integration did not influence milk yield and composition, but induced a marked reduction of somatic cell count and improved the oxidative stability of ripened caciotta cheese. In both milk and cheese, the experimental group samples were characterized by a lower concentration of saturated fatty acids and an increase in oleic acid, vaccenic acid, and rumenic acid. The aromatic profile of dairy products was also positively affected by dietary zinc intake, with an increase in concentration of carboxylic acids, aldehydes, and esters. The present results suggest a positive role of zinc in improving animal health and nutraceutical properties of milk and corresponding cheese. Taking into account the analysis of volatile compounds, zinc dietary supplementation of dairy cows should contribute to the production of cheeses with interesting organoleptic properties, although more studies are necessary to confirm the consumer acceptability of these changes. 相似文献