Browse
Submit Data
Databases
API
Help

Dataset Information

15 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Molecular recognition and scavenging of arsenate from aqueous solution using dimetallic receptors.

ABSTRACT: A series of copper(II), nickel(II) and zinc(II) dimetallic complexes were prepared and their affinities towards arsenate investigated. Indicator displacement assays (IDAs) were carried out to establish the complexes with best affinities towards arsenate. A di-zinc complex (3) was selected and its arsenate-binding abilities investigated by isothermal titration calorimetry (ITC). The X-ray crystal structure of this metallo-receptor bound to arsenate is also reported, which allowed us to establish the binding mode between 3 and this oxyanion. Immobilising 3 onto HypoGel resin yielded a novel adsorbent (Zn-HypoGel) with high affinity for arsenate. Adsorption of arsenate from competitive solutions and natural groundwater was greater than that of the commercially used iron oxide Bayoxide E33. Zn-HypoGel could be efficiently and simply regenerated by washing with sodium acetate solution.

SUBMITTER: Moffat CD

PROVIDER: S-EPMC4517099 | biostudies-literature |

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Similar Datasets

Molecular recognition of organic ammonium ions in solution using synthetic receptors.

Project description:Ammonium ions are ubiquitous in chemistry and molecular biology. Considerable efforts have been undertaken to develop synthetic receptors for their selective molecular recognition. The type of host compounds for organic ammonium ion binding span a wide range from crown ethers to calixarenes to metal complexes. Typical intermolecular interactions are hydrogen bonds, electrostatic and cation-? interactions, hydrophobic interactions or reversible covalent bond formation. In this review we discuss the different classes of synthetic receptors for organic ammonium ion recognition and illustrate the scope and limitations of each class with selected examples from the recent literature. The molecular recognition of ammonium ions in amino acids is included and the enantioselective binding of chiral ammonium ions by synthetic receptors is also covered. In our conclusion we compare the strengths and weaknesses of the different types of ammonium ion receptors which may help to select the best approach for specific applications.

| S-EPMC2874414 | biostudies-literature

Comparative study on synchronous adsorption of arsenate and fluoride in aqueous solution onto MgAlFe-LDHs with different intercalating anions.

Project description:In this study, a series of MgAlFe-LDHs (Cl-, NO3 -, intercalation, and calcined products of a CO3 2- interlayer) was synthesized and used for adsorption of arsenate and fluoride in individual contaminants and coexisting pollutant systems. Effects of various factors such as initial pH of solution, dosage of materials, coexisting ions, contact time, and initial pollutant concentrations were evaluated. Experimental results showed that different intercalating anions had a significant effect on adsorption performance of arsenate and fluoride in water. The adsorption of arsenate and fluoride on MgAlFe-CLDH, MgAlFe-Cl-LDH or MgAlFe-NO3-LDH can be described by different adsorption isotherm equations. During the simultaneous removal process, arsenate and fluoride competed for adsorption sites of the adsorbent materials, and the fluoride ions had advantages in the competitive adsorption on MgAlFe-Cl-LDH and MgAlFe-NO3-LDH. MgAlFe-NO3-LDH was used to adsorb arsenate and fluoride in coexisting pollution systems (the concentration of each pollutant was 2 mg L-1, the adsorbent dosage was 1.5 g L-1). The remaining arsenic concentration was reduced to less than 10 μg L-1 and the remaining fluoride ion concentration to below 20 μg L-1 which meets the World Health Organization's, EPA's and China's drinking water standards for arsenic and fluoride limits. A possible mechanism is discussed with support from further XRD, SEM, and XPS analysis of the materials after their adsorption.

| S-EPMC9086567 | biostudies-literature

Supramolecular ferric porphyrins as cyanide receptors in aqueous solution.

Project description:All fundamental data about binding of the cyanide to a supramolecular complex composed of a per-O-methylated ?-cyclodextrin dimer having an imidazole linker (Im3CD) and an anionic ferric porphyrin (Fe((III))TPPS) indicate that the Fe((III))TPPS/Im3CD complex is much better as an cyanide receptor in vivo than hydroxocobalamin, whose cyanide binding ability is lowered by its strong binding to serum proteins in the blood.

| S-EPMC4018087 | biostudies-other

Molecular-dynamics simulations of urea nucleation from aqueous solution.

Project description:Despite its ubiquitous character and relevance in many branches of science and engineering, nucleation from solution remains elusive. In this framework, molecular simulations represent a powerful tool to provide insight into nucleation at the molecular scale. In this work, we combine theory and molecular simulations to describe urea nucleation from aqueous solution. Taking advantage of well-tempered metadynamics, we compute the free-energy change associated to the phase transition. We find that such a free-energy profile is characterized by significant finite-size effects that can, however, be accounted for. The description of the nucleation process emerging from our analysis differs from classical nucleation theory. Nucleation of crystal-like clusters is in fact preceded by large concentration fluctuations, indicating a predominant two-step process, whereby embryonic crystal nuclei emerge from dense, disordered urea clusters. Furthermore, in the early stages of nucleation, two different polymorphs are seen to compete.

| S-EPMC4291617 | biostudies-other

Molecular species forming at the ?-Fe2O3 nanoparticle-aqueous solution interface.

Project description:We report on electronic structure measurements of the interface between hematite nanoparticles (6 nm diameter) and aqueous solutions. Using soft X-ray photoelectron spectroscopy from a liquid microjet we detect valence and core-level photoelectrons as well as Auger electrons from liquid water, from the nanoparticle-water interface, and from the interior of the aqueous-phase nanoparticles. Most noteworthy, the method is shown to be sufficiently sensitive for the detection of adsorbed hydroxyl species, resulting from H2O dissociation at the nanoparticle surface in aqueous solution. We obtain signal from surface OH from resonant, non-resonant, and from so-called partial-electron-yield X-ray absorption (PEY-XA) spectra. In addition, we report resonant photoelectron measurements at the iron 2p excitation. The respective Fe iron 2p3/2 edge (L3-edge) PEY-XA spectra exhibit two main absorption peaks with their energies being sensitive to the chemical environment of the Fe3+ ions at the nanoparticle-solution interface. This manifests in the 10Dq value which is a measure of the ligand-field strength. Furthermore, an observed intensity variation of the pre-peak, when comparing the PEY-XA spectra for different iron Auger-decay channels, can be assigned to different extents of electron delocalization. From the experimental fraction of local versus non-local autoionization signals we then find a very fast, approximately 1 fs, charge transfer time from interfacial Fe3+ into the environment. The present study, which is complementary to ambient-pressure photoemission studies on solid-electrolyte systems, also highlights the multiple aspects of photoemission that need to be explored for a full characterization of the transition-metal-oxide nanoparticle surface in aqueous phase.

| S-EPMC5961451 | biostudies-literature

Molecular dynamics simulation studies of caffeine aggregation in aqueous solution.

Project description:Molecular dynamics simulations were carried out on a system of eight independent caffeine molecules in a periodic box of water at 300 K, representing a solution near the solubility limit for caffeine at room temperature, using a newly developed CHARMM-type force field for caffeine in water. Simulations were also conducted for single caffeine molecules in water using two different water models (TIP3P and TIP4P). Water was found to structure in a complex fashion around the planar caffeine molecules, which was not sensitive to the water model used. As expected, extensive aggregation of the caffeine molecules was observed, with the molecules stacking their flat faces against one another like coins, with their methylene groups staggered to avoid steric clashes. A dynamic equilibrum was observed between large n-mers, including stacks with all eight solute molecules, and smaller clusters, with the calculated osmotic coefficient being in acceptable agreement with the experimental value. The insensitivity of the results to water model and the congruence with experimental thermodynamic data suggest that the observed stacking interactions are a realistic representation of the actual association mechanism in aqueous caffeine solutions.

| S-EPMC3189405 | biostudies-literature

Molecular dynamics simulation of four typical surfactants in aqueous solution.

Project description:The thermodynamic values of the four surfactants, anionic surfactants, nonionic surfactants, zwitterion surfactants and gemini surfactants, were calculated by molecular dynamics simulation. The calculated results of thermodynamic parameters showed that the four surfactant can form micelles spontaneously. The mainly force for micellization process is entropy-driven, and as the temperature increases, the entropy-driven contribution is gradually reduced. There are linear enthalpy-entropy compensation phenomena for the four surfactants. Among the studied four surfactants, the gemini surfactant is the easiest to form micelles and has good stability, the zwitterion surfactant is the second, and the anionic surfactant is the least stable.

| S-EPMC9059947 | biostudies-literature

A lithium ion battery using an aqueous electrolyte solution.

Project description:Energy and environmental pollution have become the two major problems in today's society. The development of green energy storage devices with good safety, high reliability, high energy density and low cost are urgently demanded. Here we report on a lithium ion battery using an aqueous electrolyte solution. It is built up by using graphite coated with gel polymer membrane and LISICON as the negative electrode, and LiFePO4 in aqueous solution as the positive electrode. Its average discharge voltage is up to 3.1?V and energy density based on the two electrode materials is 258?Wh kg(-1). It will be a promising energy storage system with good safety and efficient cooling effects.

| S-EPMC4916472 | biostudies-literature

Phenol removal from aqueous solution using Citrullus colocynthis waste ash.

Project description:Phenol is a hazardous organic chemical that introduced into the environment by industrial and pharmaceutical discharges. As a versatile option for phenol removal, adsorption would be viable if it accompanying with low cost adsorbents. This article described a natural, very cheap and local available adsorbent for phenol removal. Phenol showed a high affinity to Citrullus colocynthis waste ash which mainly composed of SiO2 (41.6%), Al2O3 (17.3%) and MgO (15.9%). Up to 70% of phenol adsorbed in the first 30 min of agitation. The phenol removal was increased by increasing adsorbent dose (0.5-10 g/L) and decreasing pH (2-12) and pollutant concentration (10-100 mg/L). The positive value of ∆H° in thermodynamic data (0.06) revealed that the process is endothermic. The high and positive value of ∆S° (13.01) and negative values of ∆G° (- 5.36 to - 7.28), showed a high affinity of phenol to the adsorbent and the spontaneous nature of the adsorption. Isotherm modelling revealed that the phenol molecules adsorbed in multilayer with the maximum adsorption capacity of 173.2 mg/g. The rate limiting step in the sorption process was chemisorption, based on the kinetic data.

| S-EPMC5996314 | biostudies-literature

Structural basis for molecular recognition at serotonin receptors.

Project description:Serotonin or 5-hydroxytryptamine (5-HT) regulates a wide spectrum of human physiology through the 5-HT receptor family. We report the crystal structures of the human 5-HT1B G protein-coupled receptor bound to the agonist antimigraine medications ergotamine and dihydroergotamine. The structures reveal similar binding modes for these ligands, which occupy the orthosteric pocket and an extended binding pocket close to the extracellular loops. The orthosteric pocket is formed by residues conserved in the 5-HT receptor family, clarifying the family-wide agonist activity of 5-HT. Compared with the structure of the 5-HT2B receptor, the 5-HT1B receptor displays a 3 angstrom outward shift at the extracellular end of helix V, resulting in a more open extended pocket that explains subtype selectivity. Together with docking and mutagenesis studies, these structures provide a comprehensive structural basis for understanding receptor-ligand interactions and designing subtype-selective serotonergic drugs.

| S-EPMC3644373 | biostudies-literature

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

Tweets

OmicsDI Databases

PRIDE
PeptideAtlas
MassIVE
JPOST Repository
Physiome Model Repository

EGA
EVA
ENA
LINCS
PAXDB
Cell Collective

MetaboLights
Metabolomics Workbench
MetabolomeExpress
GNPS
BioModels
FAIRDOMHub

ArrayExpress
dbGaP
ExpressionAtlas
GEO
NODE

Information

Databases
Help
API
Contact us
Code on GitHub
Terms of use
Submit Data