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Ligand Capable (ligand + capable)

Distribution by Scientific Domains
Life Sciences50%
Chemistry50%

Selected Abstracts

Sequential Stereoselective Catalysis: Two Single-Flask Reactions of a Substrate in the Presence of a Bifunctional Chiral Ligand and Different Transition Metals

EUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 8 2003
Rita Annunziata
Abstract A new bifunctional ligand capable of promoting different stereoselective catalytic transformations in combination with different transition metals has been prepared by connecting with a spacer a bis(oxazoline) to dihydroquinidine; this ligand was employed in a one-flask procedure in which methyl (E)-3-(4-vinylphenyl)propenoate underwent first cyclopropanation at the electron-rich double bond and then dihydroxylation at the electron-poor alkene to afford a product containing four stereocenters with complete regiocontrol and high stereoselectivity. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003) [source]

A Synthetic Peptide Ligand of Neural Cell Adhesion Molecule (NCAM) IgI Domain Prevents NCAM Internalization and Disrupts Passive Avoidance Learning

JOURNAL OF NEUROCHEMISTRY, Issue 6 2000
Andrew G. Foley
Abstract: The neural cell adhesion molecule (NCAM) mediates cell adhesion and signal transduction through trans -homophilic- and/or cis -heterophilic-binding mechanisms. Intraventricular infusions of anti-NCAM have revealed a functional requirement of NCAM for the consolidation of memory in rats and chicks in a specific interval 6-8 h after training. We have now extended these studies to a synthetic peptide ligand of NCAM (C3) with an affinity for the IgI domain and the capability of inhibiting NCAM-mediated neurite outgrowth in vitro. Intraventricular administration of a single 5 ,g bolus of C3 strongly inhibited recall of a passive avoidance response in adult rats, when given during training or in the 6-8-h posttraining period. The effect of C3 on memory consolidation was similar to that obtained with anti-NCAM as the amnesia was not observed until the 48-h recall time. The unique amnesic action of C3 during training could be related to disrupted NCAM internalization following training. In the 3-4-h posttraining period NCAM 180, the synapse-associated isoform, was down-regulated in the hippocampal dentate gyrus. This effect was mediated by ubiquitination and was prevented by C3 administration during training. These findings indicate NCAM to be involved in both the acquisition and consolidation of a passive avoidance response in the rat. Moreover, the study provides the first in vivo evidence for NCAM internalization in learning and identifies a synthetic NCAM ligand capable of modulating memory processes in vivo. [source]

Platinum(IV) Complexes of 3- and 4-Picolinic Acids Containing Ammine or Isopropylamine Ligands , Synthesis, Characteri­zation, X-ray Structures, and Evaluation of Their Cytotoxic Activity against Cancer Cell Lines,

EUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 30 2008
María J. Macazaga
Abstract The preparation and characterization of the new complexes trans -[PtCl4(NH3)(3-picolinic acid)] (1), trans -[PtCl4{NH2CH(CH3)2}(3-picolinic acid)] (2), trans -[PtCl4(NH3)(4-picolinic acid)] (3), and trans -[PtCl4{NH2CH(CH3)2}(4-picolinic acid)] (4) are described. The main structural feature of these complexes is the presence of ligands capable of multiple hydrogen-bonding interactions. Crystals of 1, 2, 3, and 4 suitable for single-crystal X-ray diffraction were grown, and the molecular structures of these compounds are discussed. In contrast to the inactive parent PtII complexes, the PtIV complexes displayed cytotoxic activity against various cancer cell lines used at the National Cancer Institute (NCI) for in vitro screens. Once more, the isopropylamine derivatives showed the best cytotoxicity values. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008) [source]

Natural Occurring Polyphenols as Template for Drug Design.

CHEMICAL BIOLOGY & DRUG DESIGN, Issue 1 2009
Focus on Serine Proteases
Several major physio-pathological processes, including cancer, inflammatory states and thrombosis, are all strongly dependent upon the fine regulation of proteolytic enzyme activities, and dramatic are the consequences of unbalanced equilibria between enzymes and their cognate inhibitors. In this perspective, the discovery of small-molecule ligands able to modulate catalytic activities has a massive therapeutic potential and is a stimulating goal. Numerous recent experimental evidences revealed that proteolytic enzymes can be opportunely targeted, reporting on small ligands capable of binding to these biological macromolecules with drug-like potencies, and primarily with comparable (or even higher) efficiency with respect to their endogenous binding partner. In particular, natural occurring polyphenols and their derivatives recently disclosed these intriguing abilities, making them promising templates for drug design and development. In this review, we compared the inhibitory capacities of a set of monomeric polyphenols toward serine proteases activity, and finally summarized the data with an emphasis on the derivation of a pharmacophore model. [source]