42 results match your criteria: "Newcastle University Newcastle upon Tyne NE1 7RU UK.[Affiliation]"

Diethylene glycol dimethacrylate (DEG)-crosslinked polystyrene (PS) resin offers a promising alternative to traditional divinyl benzene (DVB)-PS resin for solid-phase peptide synthesis (SPPS), particularly for challenging sequences with hydrophobic or bulky amino acids. DEG-PS resin's reduced hydrophobicity and enhanced flexibility improve synthesis efficiency, yielding peptides up to 28 residues with higher purities and yields compared to DVB-PS. In various syntheses, DEG-PS outperformed DVB-PS resin, with higher purities and yields for challenging peptides such as ABC analogue (73.

View Article and Find Full Text PDF

Metallic sealants are widely used with high-temperature membranes. Here we show that their use in supported molten-salt membranes results in order-of-magnitude differences in CO flux and introduces O co-permeation. The 'short-circuiting' effect they introduce has important implications for the design of future experiments, and the interpretation of past work.

View Article and Find Full Text PDF

This study develops quantifiable metrics to describe the resilience of Water Resource Recovery Facilities (WRRFs) under extreme stress events, including those posed by long-term challenges such as climate change and population growth. Resilience is the ability of the WRRFs to withstand adverse events while maintaining compliance or an operational level of service. Existing studies lack standardised resilience measurement methods.

View Article and Find Full Text PDF
Article Synopsis
  • A four-component Ugi reaction is introduced for creating novel C-N atropisomeric peptide analogues, using common materials like anilines and aldehydes to achieve complex compounds with high yields and strong stereoselectivity.
  • Adjusting the reaction temperature allows for stereodivergent outcomes, enabling the selective formation of either diastereoisomer from the same starting materials while maintaining excellent stereocontrol.
  • Research includes detailed experimental and computational analysis of the reaction mechanism, revealing that the new atropisomeric compounds exhibit varying levels of inhibitory activity, highlighting the importance of the different atropisomers' structures in their efficacy.
View Article and Find Full Text PDF

Understanding diffusion mechanisms in solid electrolytes is crucial for advancing solid-state battery technologies. This study investigates the role of structural disorder in Li PS Br argyrodites using molecular dynamics, focusing on the correlation between key structural descriptors and Li-ion conductivity. Commonly suggested parameters, such as configurational entropy, bromide site occupancy, and bromine content, correlate with Li-ion diffusivity but do not consistently explain conductivity trends.

View Article and Find Full Text PDF

Vanadium redox flow batteries have applications for large-scale electricity storage. This paper reports the influence of carbon structural characteristics of sustainable walnut shell-derived carbons in carbon/polyvinylidene fluoride composite electrodes on vanadium redox reactions. Pyrolysis, gasification, and chemical treatment procedures were used to modify the structural characteristics of carbons.

View Article and Find Full Text PDF

The abyssomicins are a structurally intriguing family of bioactive natural products that include compounds with potent antibacterial, antitumour and antiviral activities. The biosynthesis of the characteristic abyssomicin spirotetronate core occurs an enzyme-catalysed intramolecular Diels-Alder reaction, which proceeds one of two distinct stereochemical pathways to generate products differing in configuration at the C15 spirocentre. Using the purified spirotetronate cyclases AbyU (from abyssomicin C/atrop-abyssomicin C biosynthesis) and AbmU (from abyssomicin 2/neoabyssomicin biosynthesis), in combination with synthetic substrate analogues, here we show that stereoselectivity in the spirotetronate-forming [4 + 2]-cycloaddition is controlled by a combination of factors attributable to both the enzyme and substrate.

View Article and Find Full Text PDF

Pigments extracted from ayrampo seeds of the Peruvian-native prickly pear () were used in dye-sensitized solar cells with promising efficiencies. The performance of the solar cells was then improved the addition of citric acid to stabilise the photosensitive dye, and an efficiency of 1.41% was achieved with current output remaining stable after 7 days.

View Article and Find Full Text PDF

Mupirocin is a clinically important antibiotic produced by a -AT Type I polyketide synthase (PKS) in . The major bioactive metabolite, pseudomonic acid A (PA-A), is assembled on a tetrasubstituted tetrahydropyran (THP) core incorporating a 6-hydroxy group proposed to be introduced by α-hydroxylation of the thioester of the acyl carrier protein (ACP) bound polyketide chain. Herein, we describe an in vitro approach combining purified enzyme components, chemical synthesis, isotopic labelling, mass spectrometry and NMR in conjunction with in vivo studies leading to the first characterisation of the α-hydroxylation bimodule of the mupirocin biosynthetic pathway.

View Article and Find Full Text PDF

Climate change and increasing human activities are impacting ecosystems and their biodiversity. Quantitative measurements of essential biodiversity variables (EBV) and essential climate variables are used to monitor biodiversity and carbon dynamics and evaluate policy and management interventions. Ecosystem structure is at the core of EBVs and carbon stock estimation and can help to inform assessments of species and species diversity.

View Article and Find Full Text PDF

Deducing the conformational space for an octa-proline helix.

Chem Sci

January 2024

Molecular Photonics Laboratory, Bedson Building, School of Natural and Environmental Sciences, Newcastle University Newcastle upon Tyne NE1 7RU UK

A molecular dyad, PY-P-PER, comprising a proline octamer sandwiched between pyrene and perylene terminals has been synthesized in order to address the dynamics of electronic energy transfer (EET) along the oligo-proline chain. A simple pyrene-based control compound equipped with a bis-proline attachment serves as a reference for spectroscopic studies. The N-H NMR signal at the terminal pyrene allows distinction between and amides and, although the crystal structure for the control has the conformation, temperature-dependent NMR studies provide clear evidence for / isomerisation in D-DMSO.

View Article and Find Full Text PDF

Epoxides derived from waste biomass are a promising avenue for the production of bio-based polymers, including polyamides, polyesters, polyurethanes, and polycarbonates. This review article explores recent efforts to develop both catalytic and non-catalytic processes for the epoxidation of terpene, employing a variety of oxidizing agents and techniques for process intensification. Experimental investigations into the epoxidation of limonene have shown that these methods can be extended to other terpenes.

View Article and Find Full Text PDF

The Lennard-Jones potential is the most widely-used function for the description of non-bonded interactions in transferable force fields for the condensed phase. This is not because it has an optimal functional form, but rather it is a legacy resulting from when computational expense was a major consideration and this potential was particularly convenient numerically. At present, it persists because the effort that would be required to re-write molecular modelling software and train new force fields has, until now, been prohibitive.

View Article and Find Full Text PDF

Anthropogenic carbon dioxide (CO) emissions contribute significantly to global warming and deplete fossil carbon resources, prompting a shift to bio-based raw materials. The two main technologies for reducing CO emissions are capturing and either storing or utilizing it. However, while capture and storage have high reduction potential, they lack economic feasibility.

View Article and Find Full Text PDF

General methodologies enabling the two-carbon homologation of pyrrolidine and piperidine systems have yet to be developed. Herein we report that palladium-catalysed allylic amine rearrangements enable efficient two-carbon ring expansion of 2-alkenyl pyrrolidine and piperidines to their azepane and azocane counterparts. Conditions are mild, tolerant of a range of functional groups and the process can occur with high enantioretention.

View Article and Find Full Text PDF

Origin of intersystem crossing in highly distorted organic molecules: a case study with red light-absorbing ,,,-boron-chelated Bodipys.

Chem Sci

May 2023

LENS (European Laboratory for Non-Linear Spectroscopy) Via N. Carrara 1 50019 Sesto Fiorentino (FI) Italy

To explore the relationship between the twisted π-conjugation framework of aromatic chromophores and the efficacy of intersystem crossing (ISC), we have studied a ,,,-boron-chelated Bodipy derivative possessing a severely distorted molecular structure. Surprisingly, this chromophore is highly fluorescent, showing inefficient ISC (singlet oxygen quantum yield, = 12%). These features differ from those of helical aromatic hydrocarbons, where the twisted framework promotes ISC.

View Article and Find Full Text PDF

We report a push-pull BODIPY-based dye functionalised with an electronegative SF group at the position for applications in photocathodes in tandem dye-sensitized solar cells (DSSCs). The push-pull character enhances charge-transfer from the mesoporous NiO cathode surface towards the redox mediator. A Knoevenagel condensation reaction was used to introduce the carboxylic acid to anchor the dye to the oxide surface, a styryl linker which increases the conjugation in the molecule and shifts the absorption to the red.

View Article and Find Full Text PDF

Photochemical reactions in solution are governed by a complex interplay between transient intramolecular electronic and nuclear structural changes and accompanying solvent rearrangements. State-of-the-art time-resolved X-ray solution scattering has emerged in the last decade as a powerful technique to observe solute and solvent motions in real time. However, disentangling solute and solvent dynamics and how they mutually influence each other remains challenging.

View Article and Find Full Text PDF

In recent years, the development of targeted covalent inhibitors has gained popularity around the world. Specific groups (electrophilic warheads) form irreversible bonds with the side chain of nucleophilic amino acid residues, thus changing the function of biological targets such as proteins. Since the first targeted covalent inhibitor was disclosed in the 1990s, great efforts have been made to develop covalent ligands from known reversible leads or drugs by addition of tolerated electrophilic warheads.

View Article and Find Full Text PDF

Aerogel cellulose materials were synthesised from and different crosslinkers, such as kymene and a mixture of polyvinyl alcohol (PVA) and glutaraldehyde (GA). The effects of using a magnetic stirrer and ultrasonic methods were investigated. The results show that materials prepared using ultrasonic methods have higher porosity and lower density.

View Article and Find Full Text PDF

This work reports the first known synthesis of α-pinane carbonate from an α-pinene derivative. Pinane carbonate is potentially useful as a monomer for poly(pinane carbonate), which would be a sustainable bio-based polymer. α-Pinene is a major waste product from the pulp and paper industries and the most naturally abundant monoterpene in turpentine oil.

View Article and Find Full Text PDF

The authors aim to develop siRNA therapeutics for cancer that can be administered systemically to target tumors and retard their growth. The efficacy of systemic delivery of siRNA to tumors with nanoparticles based on lipids or polymers is often compromised by their rapid clearance from the circulation by the liver. Here, multifunctional cationic and anionic siRNA nanoparticle formulations are described, termed receptor-targeted nanocomplexes (RTNs), that comprise peptides for siRNA packaging into nanoparticles and receptor-mediated cell uptake, together with lipids that confer nanoparticles with stealth properties to enhance stability in the circulation, and fusogenic properties to enhance endosomal release within the cell.

View Article and Find Full Text PDF

The aqueous equimolar reaction of Ag(i) ions with the thionucleoside enantiomer (-)6-thioguanosine, ((-)6tGH), yields a one-dimensional coordination polymer {Ag(-)tG} , the self-assembly of which generates left-handed helical chains. The resulting helicity induces an enhanced chiro-optical response compared to the parent ligand. DFT calculations indicate that this enhancement is due to delocalisation of the excited state along the helical chains, with 7 units being required to converge the calculated CD spectra.

View Article and Find Full Text PDF

This study reports substantial improvement in the process for oxidising α-pinene, using environmentally friendly HO at high atom economy (∼93%) and selectivity to α-pinene oxide (100%). The epoxidation of α-pinene with HO was catalysed by tungsten-based polyoxometalates without any solvent. The variables in the screening parameters were temperatures (30-70 °C), oxidant amount (100-200 mol%), acid concentrations (0.

View Article and Find Full Text PDF

Methane is the main component of biogas, which could be used as a renewable energy source for electricity, source of heat, and biofuel production after upgrading from biogas. It also contains toxic compounds which cause environmental and human health problems. Therefore, in this work, the removal of a toxic compound (toluene) from methane gas was studied using a dielectric barrier discharge (DBD) reactor.

View Article and Find Full Text PDF