Search results for "Supramolecular"
showing 10 items of 830 documents
Magnetic Control over the Fractal Dimension of Supramolecular Rod Networks
2021
<p>Controlling supramolecular polymerization is of fundamental importance to create advanced materials and devices. Here we show that the thermodynamic equilibrium of Gd<sup>3+</sup>-bearing supramolecular rod networks is shifted reversibly at room temperature in a static magnetic field of up to 2 T. Our approach opens opportunities to control the structure formation of other supramolecular or coordination polymers that contain paramagnetic ions.</p>
Applications of guanine quartets in nanotechnology and chemical biology
2019
Guanine and related nucleobases such as guanosine, deoxyguanosine and isoguanosine are notable molecular tools for designing functional supramolecular assemblies. This popularity originates in their ability to self-assemble via a unique topological pluralism — as isolated nucleobases, discrete macrocyclic quartets and virtually infinite linear ribbons — that endows them with a considerable functional versatility. Many programmes have been launched to fine-tune the chemical properties of guanine derivatives, to make them usable under different experimental conditions, such as in organic or aqueous environments, and responsive to external stimuli, such as ionic strength, pH, light or temperat…
Complejos de ligandos azamacrocíclicos como miméticos de enzimas con actividad antioxidante
2019
The imbalance between the generation and clearance of reactive oxygen species (ROS) causes oxidative stress, which is related to a variety of health issues that include neurodegenerative disorders such as Parkinson’s and Alzheimer’s disease. In order to remove ROS, living organisms have developed a battery of protective enzymes, such as superoxide dismutases (SODs). Although SOD enzymes have shown therapeutic efficacy, their use has severe drawbacks such as the absence of oral activity, immunogenicity, short half-life and low cell permeability. Therefore, low-molecular weight mimetics may offer better outcomes regarding properties such as lack of antigenicity, good tissue penetrance, high s…
Effects of the net charge on abundance and stability of supramolecular surfactant aggregates in gas phase
2011
Self-assembling of amphiphilic molecules under electrospray ionization (ESI) conditions is characterized by quite unexpected phenomenology. The noticeable differences with respect to the condensed phase are attributable to the absence of the surfactant-solvent interactions, the presence of net charge in the aggregates, and the strong deviation from equilibrium conditions. Aiming to investigate the effects of the net charge on abundance and stability of supramolecular surfactant aggregates, positively and negatively charged aggregates of sodium bis(2-ethylhexyl)sulfosuccinate (AOT) and sodium methane sulfonate (MetS), butane sulfonate (ButS) and octane sulfonate (OctS) have been studied by E…
Oligoamide Foldamers as Helical Chloride Receptors-the Influence of Electron-Withdrawing Substituents on Anion-Binding Interactions.
2019
The anion-binding properties of three closely related oligoamide foldamers were studied using NMR spectroscopy, isothermal titration calorimetry and mass spectrometry, as well as DFT calculations. The 1 H NMR spectra of the foldamers in [D6 ]acetone solution revealed partial preorganization by intramolecular hydrogen bonding, which creates a suitable cavity for anion binding. The limited size of the cavity, however, enabled efficient binding by the inner amide protons only for the chloride anion resulting in the formation of a thermodynamically stable 1:1 complex. All 1:1 chloride complexes displayed a significant favourable contribution of the entropy term. Most likely, this is due to the …
Nuevos ligandos poliamínicos de tipo escorpiando para aplicaciones biomédicas
2016
La presente Tesis Doctoral nace en el marco del proyecto Consolider titulado “Aplicación de la Química Supramolecular al Diseño, Síntesis y Estudio de Compuestos Bioactivos de Acción Antiinflamatoria, Antitumoral o Antiparasitaria” (CSD2010-00065, BOE del 27 de febrero de 2010). El principal objetivo de este proyecto era la formación en España de un grupo de investigación multidisciplinar dedicado a la Química Médica Supramolecular (SUPRAMED, www.supramedic.com) que centraría sus esfuerzos, como su nombre indica, en el desarrollo de nuevos agentes terapéuticos con actividad antiparasitaria, antiinflamatoria o antitumoral. Como miembro investigador en este proyecto (dentro del grupo de Quími…
Antimicrobial and antioxidant supramolecular ionic liquid gels from biopolymer mixtures
2023
In this work, we describe the preparation and characterization of supramolecular ionic liquid gels based on binary mixtures of biopolymers, comprising chitosan, chitin, cellulose and lignin. The gels were obtained in ionic liquids differing in the cation or the anion, with no need for a cross-linking agent or acid treatment. The materials obtained were characterized for the minimum gelation concentration, porosity, swelling and rheological properties, finding a prominent influence of the nature of the ionic liquid anion. Then, we investigated the ability of the gels to scavenge free radicals, finding that the gels exhibit a higher antioxidant ability than their individual components. Moreov…
Polycationic Monomeric and Homodimeric Asymmetric Monomethine Cyanine Dyes with Hydroxypropyl Functionality—Strong Affinity Nucleic Acids Binders
2021
New analogs of the commercial asymmetric monomethine cyanine dyes thiazole orange (TO) and thiazole orange homodimer (TOTO) with hydroxypropyl functionality were synthesized and their properties in the presence of different nucleic acids were studied. The novel compounds showed strong, micromolar and submicromolar affinities to all examined DNA ds-polynucleotides and poly rA–poly rU. The compounds studied showed selectivity towards GC-DNA base pairs over AT-DNA, which included both binding affinity and a strong fluorescence response. CD titrations showed aggregation along the polynucleotide with well-defined supramolecular chirality. The single dipyridinium-bridged dimer showed intercalatio…
CCDC 1524052: Experimental Crystal Structure Determination
2017
UDAKOC : diaqua-(μ-1,13-dioxa-4,7,10,16,19,22-hexaazacyclotetracosane)-bis(perchlorato)-di-copper(ii) diperchlorate tetrahydrate Space Group: P21/c, Cell: a 11.8763(3)Å b 13.9146(4)Å c 13.4024(4)Å, α 90.00° β 123.439(2)° γ 90.00° Work published 2017 via Cambridge Crystallographic Data Centre.
Prodrugs of sulfacetamide: Synthesis, X-ray structure, Hirshfeld analysis, antibacterial assessment, and docking studies
2022
Abstract New prodrugs of sulfacetamide as azo compounds were synthesized and have been evidenced through elemental and spectral analyses. Their synthesis was carried out by coupling the diazonium salt of sulfacetamide with activated carbanion salt of ethyl acetoacetate at 0 ˚C to afford the hydrazono derivative 3. Other prodrugs as sulfacetamide-pyrazoles, 5a, 5b and 5c were furnished via cyclocondensation of 3 with aryl/heteroaryl hydrazines. X-ray diffraction for single crystal was used to confirm the molecular and supramolecular structures of 3. In addition, DFT studies were performed to analyze the geometric parameters and compute the electronic properties of 3 and 5a-c. Hirshfeld analy…