Showing papers by "Rosa M. Claramunt published in 2011"
TL;DR: The guanidine unit in the guise of 2-aminoimidazole in the new structural motif 2-arylamino-1,3-diaza[3]ferrocenophane 4 acts as a binding site for anions.
Abstract: The guanidine unit in the guise of 2-aminoimidazole in the new structural motif 2-arylamino-1,3-diaza[3]ferrocenophane 4 acts as a binding site for anions. The electrochemical behavior of this compound has been studied by cyclic voltammetry (CV) and differential pulse voltammetry (DPV) and was found to exhibit a quasi reversible oxidation peak, associated to the Fe(II)/Fe(III) redox couple (Ep = 440 mV), and a non-reversible oxidation wave (Ep = 817 mV), probably associated to the oxidation of the C═N unit present in the guanidine bridge. Recognition of AcO(-), PhCO(2)(-), F(-), Cl(-), and Br(-) anions by the free receptor and the less basic anions Br(-), Cl(-), and NO(3)(-) by its monoprotonated form takes place by unusual redox-ratiometric measurements and spectroscopic ((1)H NMR and UV-vis) changes.
32 citations
TL;DR: The inhibition of neuronal and inducible nitric oxide synthases (nNOS and iNOS) by a series of 36 indazoles has been evaluated, showing that most of the assayed derivatives are better iN OS than nNOS inhibitors.
24 citations
TL;DR: A three-step VS protocol is proposed, which includes the conventional docking step, a pharmacophore postfilter step, and a similarity search postprocess to improve actives from decoys selection and shows that both the overall and early VS performance improve the application.
Abstract: Conventional docking-based virtual screening (VS) of chemical databases is based on the ranking of compounds according to the values retrieved by a scoring function (typically, the binding affinity estimation). However, using the most suitable scoring function for each kind of receptor pocket is not always an effective process to rank compounds, and sometimes neither to distinguish between correct binding modes from incorrect ones. To improve actives from decoys selection, here we propose a three-step VS protocol, which includes the conventional docking step, a pharmacophore postfilter step, and a similarity search postprocess. This VS protocol is retrospectively applied to VEGFR-2 (Kdr-kinase) inhibitors. The resulting docking poses calculated using the Alpha HB scoring function implemented in MOE are postfiltered according to defined pharmacophore interactions (structure based). The selected poses are again ranked according to their molecular similarity (MACCS fingerprint) to the cognate ligand. Results...
17 citations
Abstract: A series of novel β-diketone ligands bearing alkyloxyphenyl R = C6H4OCnH2n+1 and pyridyl substituents at 1 and 3 positions of the β-diketone core [HLR(n)py] have been prepared and structurally characterized. The corresponding β-diketonate complexes [Pd(κ2-LR(n)py)2] were isolated as a mixture of cis and trans isomers each of them exhibiting the ligand in a NO- or OO-bidentate coordinative mode which were established by multinuclear NMR studies (1H, 13C and 15N). However none of those characteristics were determining to achieve liquid-crystalline properties on the new complexes. By contrast reactions of the aforementioned ligands [HLR(n)py] or those containing the pyridiniumyl substituent [HLR(n)pyH]+ towards the allyl–palladium fragment were successful to afford ionic metallomesogenic materials isolated as PF6 salts of [Pd(η3-C3H5)(κ2-HLR(n)py)][PF6] (I) and [Pd(η3-C3H5)(κ2-LR(n)pyH)][PF6] (II) types. Structural characterization and mesomorphic properties were established by multinuclear NMR and the use of DSC and POM techniques. In complexes I and II the corresponding β-diketone ligands were coordinated as neutral bidentate NO-donor or zwitterionicOO-donor systems, respectively. Complexes of type II exhibit a range of the SmC mesophases significantly greater than that found in the type I.
16 citations
TL;DR: The minimum energy values for the complexes are correlated with the experimental binding energies determined by means of (1)H NMR titrations, and their behavior in molecular recognition of urea derivatives has been approached by molecular modeling.
Abstract: Four hosts (7-10) containing 2,6-bisamidopyridine- and 2,5-bisamidopyrrole-bearing pyridyl or 1,8-naphthyridyl groups have been prepared and their structures studied by a combination of multinuclear NMR spectroscopy and X-ray crystallography. Their behavior in molecular recognition of urea derivatives, including (+)-biotin methyl ester, has been approached by molecular modeling (Monte Carlo conformational search, AMBER force field). The minimum energy values for the complexes are correlated with the experimental binding energies determined by means of (1)H NMR titrations.
13 citations
TL;DR: In this article, a partial exploration of the conformation of aliphatic linear amines has been carried out, mainly to determine the effect on the chemical shifts of neutral amines.
12 citations
TL;DR: In this article, the dihedral angles obtained in the crystal structures are in good agreement with the molecular parameters calculated using DFT B3LYP calculations employing the 6-311++G(d,p) basis set.
8 citations