1,002 results match your criteria: "School of Chemical and Physical Sciences[Affiliation]"

Preparation, analysis and toxicity characterisation of the redox metabolites of the azo food dye tartrazine.

Food Chem Toxicol

December 2023

School of Chemical and Physical Sciences, Centre for Biodiscovery, Victoria University of Wellington, PO Box 600, Wellington, 6140, New Zealand. Electronic address:

Article Synopsis
  • Tartrazine, a yellow food dye, has potential health concerns including allergic reactions and ADHD, but its full safety profile remains unclear.
  • Scientists isolated gut bacteria that could break down tartrazine, leading to the formation of a purple compound and metabolites relevant for studying its toxicity.
  • Two specific compounds related to tartrazine, SCAP and PPA, were found to be moderately toxic to human cells but not harmful to certain bacteria, suggesting a need for further research on tartrazine's safety and its byproducts.
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We investigate the previously observed superconductivity in ferromagnetic SmN in the context of the breakdown of order between two magnetic phases. Nitrogen vacancy doped SmN[Formula: see text] is a semiconductor which lies in the intermediary between ferromagnetic SmN and anti-ferromagnetic Sm. Optical data reported here corroborate the prediction that electrical transport is mediated by Sm 4f defect states, and electrical transport measurements characterise the metal-insulator transition over the doping range.

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Spinal muscular atrophy (SMA) is a genetic neuromuscular disorder caused by the reduction of survival of motor neuron (SMN) protein levels. Although three SMN-augmentation therapies are clinically approved that significantly slow down disease progression, they are unfortunately not cures. Thus, complementary SMN-independent therapies that can target key SMA pathologies and that can support the clinically approved SMN-dependent drugs are the forefront of therapeutic development.

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β-Mannosides are ubiquitous in nature, with diverse roles in many biological processes. Notably, Manβ1,4GlcNAc a constituent of the core -glycan in eukaryotes was recently identified as an immune activator, highlighting its potential for use in immunotherapy. Despite their biological significance, the synthesis of β-mannosidic linkages remains one of the major challenges in glycoscience.

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Background: Osteoporosis is a significant co-morbidity of type 1 diabetes mellitus (DM1) leading to increased fracture risk. Exercise-induced hormone 'irisin' in low dosage has been shown to have a beneficial effect on bone metabolism by increasing osteoblast differentiation and reducing osteoclast maturation, and inhibiting apoptosis and inflammation. We investigated the role of irisin in treating diabetic osteopathy by observing its effect on trabecular bone.

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Strongly confined colloidal quantum dots have been investigated for low-cost light emission and lasing for nearly two decades. However, known materials struggle to combine technologically relevant metrics of low-threshold and long inverted-state lifetime with a material gain coefficient fit to match cavity losses, particularly under electrical excitation. Here we show that bulk nanocrystals of CdS combine an exceptionally large material gain of 50,000 cm with best-in-class gain thresholds below a single exciton per nanocrystal and 3 ns gain lifetimes not limited by non-radiative Auger processes.

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Supramolecular Polymer Polymorphism: Spontaneous Helix-Helicoid Transition through Dislocation of Hydrogen-Bonded π-Rosettes.

J Am Chem Soc

October 2023

Department of Applied Chemistry and Biotechnology, Graduate School of Engineering, Chiba University, Chiba 263-8522, Japan.

Article Synopsis
  • * This study explores two distinct polymorphs formed from a large discotic supramolecular monomer, involving different stacking arrangements that yield unique photophysical properties and structures.
  • * The research reveals a kinetic stability in face-to-face stacking within polar solvents, which can convert to offset stacking, demonstrating new possibilities for helicoidal folding in supramolecular polymers without breaking apart the monomers.
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Pinacol Cross-Coupling Promoted by an Aluminyl Anion.

Chemistry

January 2024

School of Chemical and Physical Sciences, Victoria University of Wellington, P.O. Box 600, Wellington, 6012, New Zealand.

A simple sequential addition protocol for the reductive coupling of ketones and aldehydes by a potassium aluminyl grants access to unsymmetrical pinacolate derivatives. Isolation of an aluminium ketyl complex presents evidence for the accessibility of radical species. Product release from the aluminium centre was achieved using an iodosilane, forming the disilylated 1,2-diol and a neutral aluminium iodide, thereby demonstrating the steps required to generate a closed synthetic cycle for pinacol (cross) coupling at an aluminyl anion.

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The reaction of 9-diazo-9H-fluorene (fluN ) with the potassium aluminyl K[Al(NON)] ([NON] =[O(SiMe NDipp) ] , Dipp=2,6-iPr C H ) affords K[Al(NON)(κN ,N -{(fluN ) })] (1). Structural analysis shows a near planar 1,4-di(9H-fluoren-9-ylidene)tetraazadiide ligand that chelates to the aluminium. The thermally induced elimination of dinitrogen from 1 affords the neutral aluminium ketimide complex, Al(NON)(N=flu)(THF) (2) and the 1,2-di(9H-fluoren-9-yl)diazene dianion as the potassium salt, [K (THF) ][fluN=Nflu] (3).

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The SWY-type aluminosilicate zeolite, STA-30, has been synthesized via different routes to understand its defect chemistry and solid acidity. The synthetic parameters varied were the gel aging, the Al source, and the organic structure directing agent. All syntheses give crystalline materials with similar Si/Al ratios (6-7) that are stable in the activated K,H-form and closely similar by powder X-ray diffraction.

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Starting from a commercially available thioether, we report a nine-step synthesis of a 4'-thiouridine phosphoramidite building-block. We install the uracil nucleobase using Pummerer-type glycosylation of a sulfoxide intermediate followed by a series of protecting group manipulations to deliver the desired phosphite. Notably, we introduce a 3',5'-O-di-tert-butylsilylene protecting group within a 4'-thiosugar framework, harnessing this to ensure regiospecific installation of the 2'-O-silyl protecting group.

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Interaction between pentacene molecules and monolayer transition metal dichalcogenides.

Phys Chem Chem Phys

November 2023

School of Chemical and Physical Sciences, Keele University, Keele ST5 5BG, UK.

Using first-principles calculations based on density-functional theory, we investigated the adsorption of pentacene molecules on monolayer two-dimensional transition metal dichalcogenides (TMD). We considered the four most popular TMDs, namely, MoS, MoSe, WS and WSe, and we examined the structural and electronic properties of pentacene/TMD systems. We discuss how monolayer pentacene interacts with the TMDs, and how this interaction affects the charge transfer and work function of the heterostructure.

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identification of modulators of J domain protein-Hsp70 interactions in : a drug repurposing strategy against malaria.

Front Mol Biosci

August 2023

Biomedical Research and Drug Discovery Research Group, Faculty of Health Sciences, Higher Colleges of Technology, Sharjah, United Arab Emirates.

is a unicellular, intracellular protozoan parasite, and the causative agent of malaria in humans, a deadly vector borne infectious disease. A key phase of malaria pathology, is the invasion of human erythrocytes, resulting in drastic remodeling by exported parasite proteins, including molecular chaperones and co-chaperones. The survival of the parasite within the human host is mediated by heat shock protein 70s (PfHsp70s) and J domain proteins (PfJDPs), functioning as chaperones-co-chaperones partnerships.

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The increasing role of two-dimensional (2D) devices requires the development of new techniques for ultrafast control of physical properties in 2D van der Waals (vdW) nanolayers. A special feature of heterobilayers assembled from vdW monolayers is femtosecond separation of photoexcited electrons and holes between the neighboring layers, resulting in the formation of Coulomb force. Using laser pulses, we generate a 0.

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Introduction: Metabolomics produces vast quantities of data but determining which metabolites are the most relevant to the disease or disorder of interest can be challenging.

Objectives: This study sought to demonstrate how behavioral models of psychiatric disorders can be combined with metabolomics research to overcome this limitation.

Methods: We designed a preclinical, untargeted metabolomics procedure, that focuses on the determination of central metabolites relevant to substance use disorders that are (a) associated with changes in behavior produced by acute drug exposure and (b) impacted by repeated drug exposure.

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Fluorinated nucleosides, nucleotides and sugar nucleotides.

Future Med Chem

July 2023

School of Chemical and Physical Sciences and Centre for Glycoscience, Keele University, Keele, Staffordshire, ST5 5BG, UK.

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Reported herein is a scalable chemical synthesis of disaccharide building blocks for heparan sulfate (HS) oligosaccharide assembly. The use of d-glucuronate-based acceptors for dehydrative glycosylation with d-glucosamine partners is explored, enabling diastereoselective synthesis of appropriately protected HS disaccharide building blocks (d-GlcN-α-1,4-d-GlcA) on a multigram scale. Isolation and characterization of key donor (1,2 glycal)- and acceptor (ortho-ester, anhydro)-derived side products ensure methodology improvements to reduce their formation; protecting the d-glucuronate acceptor at the anomeric position with a -methoxyphenyl unit proves optimal.

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The pharmacological effectiveness of indoles, benzoxazepines and benzodiazepines initiated our synthesis of indole fused benoxazepine/benzodiazepine heterocycles, along with enhanced biological usefulness of the fused rings. Activated indoles , and were synthesized using modified Bischler indole synthesis rearrangement. Indole was substituted with the trichloroacetyl group at the C position, yielding exclusively due to the increased nucleophilic character of C.

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Three distinct routes are reported to the soluble, dihydridoaluminate compounds, AM[Al(NON )(H) ] (AM=Li, Na, K, Rb, Cs; [NON ] =[O(SiMe NDipp) ] ; Dipp=2,6-iPr C H ) starting from the alkali metal aluminyls, AM[Al(NON )]. Direct H hydrogenation of the heavier analogues (AM=Rb, Cs) produced the first examples of structurally characterized rubidium and caesium dihydridoaluminates, although harsh conditions were required for complete conversion. Using 1,4-cyclohexadiene (1,4-CHD) as an alternative hydrogen source in transfer hydrogenation reactions provided a lower energy pathway to the full series of products for AM=Li-Cs.

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The demand for fluorescent organic dyes across a broad range of applications has led to investigation into tuneable emission dyes. The tuneable nature of these dyes makes them desirable for applications in a variety of fields, including organic light-emitting diodes (OLEDs), optical sensing devices, and fluorescence imaging. In recent investigations, there have only been a handful of mechanisms used to tune emission.

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Chemical synthesis of amphiphilic glycoconjugates: Access to amino, fluorinated and sulfhydryl oleyl glucosides.

Carbohydr Res

August 2023

Centre for Glycoscience, Keele University, Keele, Staffordshire, ST5 5BG, UK; Lennard-Jones Laboratory, School of Chemical and Physical Sciences, Keele University, Keele, Staffordshire, ST5 5BG, UK. Electronic address:

Amphiphilic glycoconjugates offer an important prospect for development as chemical biology tools and biosurfactants. The chemical synthesis of such materials is required to expedite such prospect, compounded by the example of oleyl glycosides. Herein, we report a mild and reliable glycosylation method to access oleyl glucosides, glycosidating oleyl alcohol with α-trichloroacetimidate donors.

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We report the reaction of the potassium aluminyl, K[Al(NON)] ([NON] = [O(SiMeNDipp)], Dipp = 2,6-iPrCH) with a series of isocyanide substrates (R-NC). In the case of Bu-NC, degradation of the isocyanide was observed generating an isomeric mixture of the corresponding aluminium cyanido-κ and -κ compounds, K[Al(NON)(H)(CN)]/K[Al(NON)(H)(NC)]. The reaction with 2,6-dimethylphenyl isocyanide (Dmp-NC), gave a C-homologation product, which in addition to C-C bond formation showed dearomatisation of one of the aromatic substituents.

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Realizing the Continuous Chemoenzymatic Synthesis of Anilines Using an Immobilized Nitroreductase.

ACS Sustain Chem Eng

June 2023

Johnson Matthey, 28 Cambridge Science Park, Milton Rd, Cambridge CB4 0FP, United Kingdom.

The use of biocatalysis for classically synthetic transformations has seen an increase in recent years, driven by the sustainability credentials bio-based approaches can offer the chemical industry. Despite this, the biocatalytic reduction of aromatic nitro compounds using nitroreductase biocatalysts has not received significant attention in the context of synthetic chemistry. Herein, a nitroreductase (NR-55) is demonstrated to complete aromatic nitro reduction in a continuous packed-bed reactor for the first time.

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The work here reflects synthesis, DFT studies, Hirshfeld charge analysis and crystal data exploration of pharmacologically important ()-2-(2-(1,3-dioxoisoindolin-2-yl)propanamido)benzoic acid methyl ester () to understand its properties for further chemical transformations. The methyl anthranilate () was produced by the esterification of anthranilic acid in an acidic medium. The phthaloyl-protected alanine () was rendered by the fusion of alanine with phthalic anhydride at 150 °C, followed by coupling with () furnished isoindole ().

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Ductal carcinoma in-situ (DCIS) accounts for 20-25% of all new breast cancer diagnoses. DCIS has an uncertain risk of progression to invasive breast cancer and a lack of predictive biomarkers may result in relatively high levels (~ 75%) of overtreatment. To identify unique prognostic biomarkers of invasive progression, crystallographic and chemical features of DCIS microcalcifications have been explored.

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