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101.
Tuccinardi T Zizzari AT Brullo C Daniele S Musumeci F Schenone S Trincavelli ML Martini C Martinelli A Giorgi G Botta M 《Organic & biomolecular chemistry》2011,9(12):4448-4455
A(1) adenosine receptor antagonists have been proposed to possess an interesting range of potential therapeutic applications. We have already reported the synthesis and the biological characterization of a family of pyrazolo[3,4-b]pyridine derivatives as A(1) adenosine ligands endowed with an antagonistic profile. In the present work, we report the LC separation of enantiomers of our most active A(1) antagonists together with the determination of their absolute configuration by means of X-ray crystal structure analysis. Biological assays confirmed a different activity for the two enantiomers, with the R one showing the higher human A(1)AR affinity. We also developed a homology model of this receptor subtype in order to suggest a binding disposition of the ligands into the hA(1)AR. All of the obtained data suggest that the compound's chirality plays a key role in A(1) affinity. 相似文献
102.
Campagna S Cavazzini M Cusumano M Di Pietro ML Giannetto A Puntoriero F Quici S 《Inorganic chemistry》2011,50(21):10667-10672
Efficient intercalation of a luminescent Ir(III) complex exclusively made of polypyridine ligands in natural and synthetic biopolymers is reported for the first time. The emission of the complex is largely enhanced in the presence of [poly(dA-dT)(2)] and strongly quenched in the presence of [poly(dG-dC)(2)]. By comparing the emission decays in DNA and in synthetic polynucleotides, it is proposed that the emission quenching of the title compound by guanine residues in DNA is no longer effective over a distance of four dA-dT base pairs. 相似文献
103.
We present here a general framework, expressed by a system of nonlinear differential equations, suitable for the modeling of taxation and redistribution in a closed society. This framework allows one to describe the evolution of income distribution over the population and to explain the emergence of collective features based on knowledge of the individual interactions. By making different choices of the framework parameters, we construct different models, whose long-time behavior is then investigated. Asymptotic stationary distributions are found, which enjoy similar properties as those observed in empirical distributions. In particular, they exhibit power law tails of Pareto type and their Lorenz curves and Gini indices are consistent with some real world ones. 相似文献
104.
We expound some results about the relationships between the Jacobi operators with respect to null vectors on a Lorentzian S-manifold and the Jacobi operators with respect to particular spacelike unit vectors. We study the number of the eigenvalues of such operators on Lorentzian S-manifolds satisfying the φ-null Osserman condition, under suitable assumptions on the dimension of the manifold. Then, we provide in full generality a new curvature characterization for Lorentzian S-manifolds and we use it to obtain an algebraic decomposition for the Riemannian curvature tensor of φ-null Osserman Lorentzian S-manifolds. 相似文献
105.
Deoxyfunicone, rapicone and their 5,6-epoxy-derivatives are γ-pyrone compounds with cytostatic and antiproliferative properties. Here we describe a synthesis of these compounds by carbonylative Stille coupling between kojic acid derivatives and functionalized iodo aryl compounds. The main advantages of this patent pending synthetic strategy lie in the simplicity and clean conversion of products, and in the possibility to obtain a high number of analogs by minor changes of the synthetic synthons. 相似文献
106.
Letizia?PellegriniEmail authorView authors OrcID profile 《Journal of Optimization Theory and Applications》2018,177(3):811-815
This note aims at stimulating research on set-valued optimization through image space analysis. 相似文献
107.
108.
Bartoli G Bosco M Dalpozzo R Giuliani A Marcantoni E Mecozzi T Sambri L Torregiani E 《The Journal of organic chemistry》2002,67(25):9111-9114
2-Alkylidenecycloalkanones are powerful synthons used as the key intermediates in many important syntheses. Because of their potential, a general method of preparation from readily available starting materials, under very mild conditions, was considered to be worthwhile. Cerium(III) chloride heptahydrate in combination with sodium iodide in refluxing acetonitrile promotes a regio- and stereoselective beta-elimination reaction to (E)-2-alkylidenecycloalkanones in 2-(1-hydroxyalkyl)cycloalkanones. The synthetic value of the present procedure is demonstrated by the synthesis of monoterpene (S)-(-)-pulegone (8) in its optically active form. 相似文献
109.
Evidence for Degradation of the Chrome Yellows in Van Gogh’s Sunflowers: A Study Using Noninvasive In Situ Methods and Synchrotron‐Radiation‐Based X‐ray Techniques
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Dr. Letizia Monico Prof. Koen Janssens Dr. Ella Hendriks Frederik Vanmeert Dr. Geert Van der Snickt Dr. Marine Cotte Dr. Gerald Falkenberg Prof. Brunetto Giovanni Brunetti Dr. Costanza Miliani 《Angewandte Chemie (International ed. in English)》2015,54(47):13923-13927
This paper presents firm evidence for the chemical alteration of chrome yellow pigments in Van Gogh’s Sunflowers (Van Gogh Museum, Amsterdam). Noninvasive in situ spectroscopic analysis at several spots on the painting, combined with synchrotron‐radiation‐based X‐ray investigations of two microsamples, revealed the presence of different types of chrome yellow used by Van Gogh, including the lightfast PbCrO4 and the sulfur‐rich PbCr1?xSxO4 (x≈0.5) variety that is known for its high propensity to undergo photoinduced reduction. The products of this degradation process, i.e., CrIII compounds, were found at the interface between the paint and the varnish. Selected locations of the painting with the highest risk of color modification by chemical deterioration of chrome yellow are identified, thus calling for careful monitoring in the future. 相似文献
110.
M. Letizia Ciavatta M. Pilar Lopez Gresa Margherita Gavagnin Dominique Melck Yue-Wei Guo Guido Cimino 《Tetrahedron》2007,63(6):1380-1384
Puupehenone (1) and a series of its congeners (2-6) have been isolated from a Dysidea sponge. The unprecedented 20-acetoxy-haterumadienone (2) exhibiting a five-membered contracted ring, has been characterized. In addition, stereochemical assignment of two previously reported acetone adducts of puupehenone (5 and 6) has been made. Finally, the inhibition of mitochondrial respiratory chain as well as antibacterial and antifungal activities of all compounds has been evaluated. 相似文献