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51.
Badaloni E Barbarino M Cabri W D'Acquarica I Forte M Gasparrini F Giorgi F Pierini M Simone P Ursini O Villani C 《Journal of chromatography. A》2011,1218(25):3862-3875
New monolithic HPLC columns were prepared by γ-radiation-triggered polymerization of hexyl methacrylate and ethylene glycol dimethacrylate monomers in the presence of porogenic solvents. Polymerization was carried out directly within capillary (250-200 μm I.D.) and nano (100-75 μm I.D.) fused-silica tubes yielding highly efficient columns for cap(nano)-LC applications. The columns were applied in the complete separation of core (H2A, H2B, H3, and H4) and linker (H1) histones under gradient elution with UV and/or electrospray ionization (ESI) ion trap mass spectrometry (MS) detections. Large selectivity towards H1, H2A-1, H2A-2, H2B, H3-1, H3-2 and H4 histones and complete separation were obtained within 8 min time windows, using fast gradients and very high linear flow velocities, up to 11 mm/s for high throughput applications. The method developed was the basis of a simple and efficient protocol for the evaluation of post-translational modifications (PTMs) of histones from NCI-H460 human non-small-cell lung cancer (NSCLC) and HCT-116 human colorectal carcinoma cells. The study was extended to monitoring the level of histone acetylation after inhibition of Histone DeACetylase (HDAC) enzymes with suberoylanilide hydroxamic acid (SAHA), the first HDAC inhibitor approved by the FDA for cancer therapy. Attractive features of our cap(nano)-LC/MS approach are the short analysis time, the minute amount of sample required to complete the whole procedure and the stability of the polymethacrylate-based columns. A lab-made software package ClustMass was ad hoc developed and used to elaborate deconvoluted mass spectral data (aligning, averaging, clustering) and calculate the potency of HDAC inhibitors, expressed through a Relative half maximal Inhibitory Concentration parameter, namely R_IC(50) and an averaged acetylation degree. 相似文献
52.
Occhiuto I De Luca G Villari V Romeo A Micali N Pasternack RF Scolaro LM 《Chemical communications (Cambridge, England)》2011,47(21):6045-6047
Chirality is rapidly induced in a fractal aggregate of the porphyrin t-CuPagg by addition of α-helical poly-glutamate. These results demonstrate a facile transfer of chirality via noncovalent interactions to preformed supramolecular assemblies grown in the absence of a chiral template. 相似文献
53.
Le Bahers T Pauporté T Labat F Lefèvre G Ciofini I 《Langmuir : the ACS journal of surfaces and colloids》2011,27(7):3442-3450
Acetylacetone (acacH) adsorption on ZnO (10-10) surface has been studied by a theoretical periodic approach using density functional theory. Two dissociative adsorption modes were investigated and compared to the most stable adsorption mode of formic acid. Acetylacetone appears as a suitable anchoring group for hybrid materials, with adsorption energies of the same order of magnitude as formic acid. IR spectra of the acac/ZnO systems were computed in order to determine the spectral signature of adsorption and, possibly, of each adsorption mode to follow the coordination of acac on ZnO at the experimental level. The results have been compared to Fourier transform infrared (attenuated total reflection-IR) experimental spectra. The present investigation points out the interest of acetylacetone as an anchoring group for the development of new ZnO-based functionalized hybrid layers for corrosion protection, light emitting diodes, photocatalytic systems, and dye-sensitized solar cells. 相似文献
54.
Denis Jacquemin Julien Preat Eric A. Perpète Daniel P. Vercauteren Jean‐Marie André Ilaria Ciofini Carlo Adamo 《International journal of quantum chemistry》2011,111(15):4224-4240
Using time‐dependent density functional theory and the polarizable continuum model, we have simulated the absorption spectra of an extended series of azobenzene dyes. First, we have determined a theoretical level optimal for this important class of dyes, and it turned out that a C‐PCM‐CAM‐B3LYP/6‐311+G(d,p)//C‐PCM‐B3LYP/6‐311G(d,p) approach represents an effective compromise between chemical accuracy and computational cost. In a second stage, we have compared the theoretical and experimental transition energies for 46 n → π☆ and 141 π → π☆ excitations. For the full set, that spans over a 302–565 nm domain, we obtained a mean absolute deviation of 13 nm (0.10 eV) and a linear correlation coefficient of 0.95, illustrating the accuracy of our approach, though some significant outliers pertained. In a last step, the impact of several modifications, that is, trans/cis isomerization, variation of the acidity of the medium and azo/hydrazo tautomerism have been modeled with two functionals. © 2010 Wiley Periodicals, Inc. Int J Quantum Chem, 2010 相似文献
55.
56.
P. Sreejith Shankar Serena Bigotti Paolo Lazzari Ilaria Manca Marco Spiga Monica Sani Matteo Zanda 《Tetrahedron letters》2013
Tubulysins are potent anti-mitotic natural compounds and a scalable and efficient synthetic route for generation of its analogues has been developed and extended to the synthesis of diastereoisomers and N-terminal analogues of tubulysin-U. Structure–activity-relationship studies on these synthetic analogues reaffirmed the significance of native stereochemistry of tubulysins for optimal biological activity and cytotoxicity. However, while modification of Tup stereochemistry has only minor effect on the tubulysins cytotoxicity, Tuv stereochemistry is critically important and modification of either Tuv stereocentre produced a dramatic drop in cytotoxicity. 相似文献
57.
58.
Machetti F Bucelli I Indiani G Kappe CO Guarna A 《Journal of combinatorial chemistry》2007,9(3):454-461
An efficient synthesis of unsubstituted and substituted amides based on the 6,8-dioxa-3-azabicyclo[3.2.1]octane scaffold is described. The reaction, carried out at 60 degrees C in the absence of solvent, is characterized by its mildness and ease of workup. A library of amides, was synthesized by combination of methyl esters 1-6 with various amines. In addition, the microwave-assisted automated synthesis of the library was compared with the above conventional parallel synthesis. Microwave synthesis significantly decreased the reaction time from hours to minutes. 相似文献
59.
Giampiero Bettinetti Milena Sorrenti Laura Catenacci Franca Ferrari Silvia Rossi Ilaria Salvadeo Paolo Carraro 《Journal of inclusion phenomena and macrocyclic chemistry》2007,57(1-4):329-332
Triacetyl α-cyclodextrin, triacetyl β-cyclodextrin and triacetyl γ-cyclodextrin were tested as possible hydrophobic carriers
to prolong the release of hydrophilic teicoplanin (TCP). Physical–chemical characterization of individual components, drug-carrier
physical mixtures at 0.5, 0.67 and 0.75 mass fraction of carrier, and the respective interaction products by kneading or evaporative
crystallization under microwave irradiation was carried out using differential scanning calorimetry (DSC) and thermogravimetric
analysis (TGA). In vitro drug release in pH 7.4 phosphate buffer at 37 °C was determined by intrinsic dissolution rate (IDR)
measurements on non disintegrating compressed discs. Solid-state interactions of TCP with triacetyl α-cyclodextrin by evaporative
crystallization and kneading and with triacetyl β-cyclodextrin by evaporative crystallization (probably resulting in carrier
amorphization) were demonstrated. The role of carrier hydrophobicity, carrier mass fraction and preparation method of solid
drug-carrier combinations on solid-state drug-carrier interactions and slowing down of TCP release was assessed. Modulation
of drug release can be achieved using TCP-triacetyl γ-cyclodextrin combinations at 0.5 mass fraction of carrier. 相似文献
60.