Browsing CIQUS-Artigos by Title
Now showing items 49-68 of 391
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Chiral Coalition in Helical Sense Enhancement of Copolymers: The Role of the Absolute Configuration of Comonomers
(American Chemistry Society, 2017-12-14)Both the role of the absolute configuration and the tendency of a chiral monomer to promote a certain helical scaffold in a polyphenylacetylene (PPA) —that depends on the conformational composition at the pendant group— ... -
Chiral gold–PPA nanocomposites with tunable helical sense and morphology
(Royal Society of Chemistry, 2020)A novel type of stimuli-responsive dynamic helical polymer–metal nanoparticle nanocomposite formed by a helical poly(phenylacetylene) (PPA) combined with gold nanoparticles (AuNPs) is described. Thus, several PPA copolymers ... -
Chiral information harvesting in helical poly(acetylene) derivatives using oligo(p-phenyleneethynylene)s as spacers
(Royal Society of Chemistry, 2020)A chiral harvesting transmission mechanism is described in poly(acetylene)s bearing oligo(p-phenyleneethynylene)s (OPEs) used as rigid achiral spacers and derivatized with chiral pendant groups. The chiral moieties induce ... -
Chiral nanostructure in polymers under different deposition conditions observed using atomic force microscopy of monolayers: poly(phenylacetylene)s as a case study
(Royal Society of Chemistry, 2016-10-31)Dynamic poly(phenylacetylene)s (PPAs) adopt helical structures with different elongation or helical senses depending on the types of pendants. Hence, a good knowledge of the parameters that define their structures becomes ... -
Chiral Overpass Induction in Dynamic Helical Polymers Bearing Pendant Groups with Two Chiral Centers
(Wiley, 2020)The dynamic behavior of helical polymers bearing pendant groups with two chiral centers was studied. Controlled conformational changes at the chiral units placed either closer to or further away from the main chain promote ... -
Chiral-to-Chiral Communication in Polymers: A Unique Approach to Control both Helical Sense and Chirality at the Periphery
(American Chemical Society, 2018-08-29)A novel approach to the classical Sergeants and Soldiers effect, using chiral Sergeants and chiral Soldiers, allows control over both helical and external chirality in helical polymers. In the systems reported here, it is ... -
Chitosan hydrophobic domains are favoured at low degree of acetylation and molecular weight
(Elsevier, 2013-04-03)The aggregation of chitosan (CS) has been studied as a function of concentration, degree of acetylation (DA), and degree of polymerization (DP) by means of pyrene fluorescence and rheology. Fluorescence experiments show ... -
Click Chemistry for Drug Delivery Nanosystems
(Springer, 2012)The purpose of this Expert Review is to discuss the impact of click chemistry in nanosized drug delivery systems. Since the introduction of the click concept by Sharpless and coworkers in 2001, numerous examples of click ... -
Click Chemistry with Polymers, Dendrimers, and Hydrogels for Drug Delivery
(Springer, 2012)During the last decades, great efforts have been devoted to design polymers for reducing the toxicity, increasing the absorption, and improving the release profile of drugs. Advantage has been also taken from the inherent ... -
A Combined Systematic-Stochastic Algorithm for the Conformational Search in Flexible Acyclic Molecules
(Frontiers, 2020)We propose an algorithm that is a combination of systematic variation of the torsions and Monte Carlo (or stochastic) search. It starts with a trial geometry in internal coordinates and with a set of preconditioned torsional ... -
Communication: Selection rules for tunneling splitting of vibrationally excited levels
(AIP Publishing, 2013-07-08)Five symmetry-based selection rules are formulated that relate the tunneling splitting of a vibrationally excited level to that of the ground level in molecules with a symmetric double-minimum potential. The rules, which ... -
Comparative Binding Energy (COMBINE) Analysis for Understanding the Binding Determinants of Type II Dehydroquinase Inhibitors
(Wiley, 2013-04-26)Herein we report comparative binding energy (COMBINE) analyses to derive quantitative structure–activity relationship (QSAR) models that help rationalize the determinants of binding affinity for inhibitors of type II ... -
Comparative in vitro studies on PBN loaded nanoparticles prepared by biodegradable chitosan, PLGA polymers and their PEGylated block copolymers
(Elsevier, 2014)α-phenyl-N-tert-butyl nitrone (PBN) is a neuroprotective free radical scavenger however it has low in vivo stability and blood residence time. Aim. of this study is to develop a nanoparticle formulation by using different ... -
Computer-aided design of multi-target ligands at A1R, A2AR and PDE10A, key proteins in neurodegenerative diseases
(BioMed Central, 2017)Compounds designed to display polypharmacology may have utility in treating complex diseases, where activity at multiple targets is required to produce a clinical efect. In particular, suitable compounds may be useful in ... -
Computer-Aided Structure-Based Design of Multitarget Leads for Alzheimer’s Disease
(American Chemical Society, 2015)Alzheimer’s disease is a neurodegenerative pathology with unmet clinical needs. A highly desirable approach to this syndrome would be to find a single lead that could bind to some or all of the selected biomolecules that ... -
Concise, enantioselective, and versatile synthesis of (−)-Englerin A Based on a platinum-catalyzed [4C+3C] cycloaddition of allenedienes
(WILEY-VCH Verlag GmbH, 2016-10-13)A practical synthesis of (−)-englerin A was accomplished in 17 steps and 11 % global yield from commercially available achiral precursors. The key step consists of a platinum-catalyzed [4C+3C] allenediene cycloaddition ... -
Concurrent and orthogonal gold(I) and ruthenium(II) catalysis inside living cells
(Springer Nature, 2018)The viability of building artificial metabolic pathways within a cell will depend on our ability to design biocompatible and orthogonal catalysts capable of achieving non-natural transformations. In this context, transition ... -
Copper(I)-Catalyzed Tandem Carboarylation/Cyclization of Alkynyl Phosphonates with Diaryliodonium Salts
(American Chemical Society, 2017-08-02)A copper-catalyzed tandem carboarylation/cyclization of alkynyl phosphonates with diaryliodonium salts is reported. The reaction gives straightforward access to valuable cyclic enol phosphonates in good yields under mild ... -
Copper(II) Complexes of Cyclams Containing Nitrophenyl Substituents: Push–Pull Behavior and Scorpionate Coordination of the Nitro Group
(American Chemical Society, 2015)The three nitrophenyl–cyclam derivatives (nitrocyclams): 1-(4-nitrophenyl)-1,4,8,11-tetraazacyclotetradecane (2), 1-(2-nitrophenyl)-1,4,8,11-tetraazacyclotetradecane (3), and 1-(2,4-dinitrophenyl)-1,4,8,11-tetraazacyclotetradecane ... -
Copper-catalyzed O-alkenylation of phosphonates
(Beilstein Institute, 2020)Copper catalysis allows the direct oxygen alkenylation of dialkyl phosphonates with alkenyl(aryl)iodonium salts with selective transfer of the alkenyl group. This novel methodology proceeds with a wide range of phosphonates ...