pH-Responsive Fluorescence Turn-On Copper(II)-Probe for Nitric Oxide Detection: A Reductive Nitrosylation Approach.

Nitric oxide (NO) is one of the crucial biological signaling molecules, yet achieving its selective and spatiotemporal detection in in-situ/invitro or biological systems at specific pH remains a significant challenge. Hence, a probe capable of directly detecting NO would be immensely valuable in understanding its reactivity and biological functions. Here, to develop a Cu(II)-based probe for selective NO detection, we synthesized a Cu(II)-complex (1) using a N3-tridentate ligand having a pendant dansyl fluorophore (L) and evaluated it's NO reactivity under varying pH conditions.

Wadjet-Keeping a watchful eye on circular DNA.

The structural maintenance of chromosomes (SMC)-family Wadjet complex restricts plasmid transformation in bacteria through a distinctive mechanism coupling DNA loop extrusion and cleavage. In this issue of Structure, Roisné-Hamelin et al. report the biochemical reconstitution and structure of a type II Wadjet complex, revealing a shared overall mechanism and notable architectural differences compared to related type I complexes.

Exciton interactions in crystalline crossed diazapentacene.

The presence of heteroatoms and their influence on excitonic interactions are vital and can help engineer the optoelectronic properties in molecular assemblies. Herein, we report the effect of nitrogen atoms on excitonic coupling and the resulting optical properties of an orthogonally cross-stacked crystalline diazapentacene derivative.

Intracellular Subdegree Temperature Sensing and Dynamics by Thermoresponsive Silver Nanoclusters as Molecular Probes.

Reported herein are long-lived, red-luminescent silver nanoclusters (AgNCs) protected by the small-molecule ligand thiolactic acid, which exhibit exceptional stability (shelf life exceeding three years, photostability ∼100%), water-solubility, and high biocompatibility, making them suitable for diverse applications such as sensing and live-cell imaging. The AgNCs display extremely sensitive (>2% K) temperature-dependent luminescence, monitored by a dual approach of changes in photoluminescence intensity and excited-state lifetime, enabling precise local thermal environment monitoring with a very high-resolution temperature sensing down to subdegree levels (<0.5 K).

Molecular insights into the structure, function, and stability of the DNA polymerase processivity factor from Mycobacterium tuberculosis.

Emergence of drug resistance in Mycobacterium tuberculosis (Mtb) calls for newer drugs and drug targets. Essential proteins such as DNA polymerase (DNAP) processivity factor, also called sliding clamp (DnaN), are indispensable for bacterial survival, and are excellent drug targets. Here, we constructed a dnaN-conditional knockout in Mycobacterium smegmatis (MsmΔdnaN) and were able to successfully complement it with Mtb DnaN (DnaN).

Intracellular formate modulates a motility-invasion switch in Salmonella Typhimurium.

Host-derived short-chain fatty acids (SCFAs) are essential for Salmonella Typhimurium (STM) virulence. Formate, an SCFA found in the ileum, enhances STM invasion, but the role of the intracellular formate pool in STM pathogenesis remains poorly understood. Deletion of the pflB gene, which encodes pyruvate-formate lyase, depletes this intracellular pool, leading to reduced flagellation and increased expression of pathogenicity island-1 genes (hilA and prgH).

Construction of dansylated (fluorescent) amino acid motifs C(sp)-H arylation.

We describe the construction of a library of novel dansylated (fluorescent) phenylalanine-type unnatural amino acid scaffolds using a Pd(II)-catalyzed C(sp)-H arylation method. A literature survey revealed that, in general, the dansyl moiety is introduced at the N-terminus of amino acids. Various dansylated amino acids and peptides have been used as fluorophores or probes and are known to show promising biological activities.

Creating skeletal complexity through an interrupted Corey-Chaykovsky reaction of activated alkynes.

We present the first interrupted Corey-Chaykovsky reaction of α,β-ynones by intercepting the zwitterionic intermediates that prevail during the addition of the Corey-Chaykovsky reagent to activated alkynes. This cascade transformation uncovers a novel mechanistic feature and leverages it to construct complex polycyclic molecular architectures featuring three new carbon-carbon bonds, four new carbo- and heterocycles and four contiguous stereocenters, two of which are quaternary carbons, all in a single-pot operation. Additionally, we demonstrate the synthetic utility of these otherwise unprecedented molecules.

Decoding information entropy of fatty acid and phospholipid vesicles ordering combinatorial output of hydrazones.

Leveraging information entropy to quantitatively measure the organizational diversity and complexity of different chemical systems is a compelling need for next-generation supramolecular and systems chemistry. It can also be a strategy for digitalizing and enabling the bottom-up development of life-like complex systems following probable origin-of-life scenarios. According to the lipid world hypothesis, lipid molecules appear first to facilitate compartmentalization, catalysis, information processing, It is envisaged that fatty acid-based vesicles are more primitive than phospholipid vesicles.

Reversible Ring Oxidation of a β-β Linked 24π Antiaromatic Sapphyrin to a 22π Aromatic Dication Dimer.

Unlike aromatic porphyrins, conventional oxidative coupling reactions do not yield dimeric or oligomeric antiaromatic porphyrinoids. We describe here the first example of a β-β-linked antiaromatic expanded porphyrinoid through a novel synthetic strategy. It contains two 24π sapphyrin units, which undergo independent reversible two-electron oxidation to yield the aromatic tetracation.

Hepatic Encephalopathy: Insights Into the Impact of Metabolic Precipitates.

Hepatic failure is a severe condition marked by the progressive or sudden loss of liver function, broadly categorized into acute liver failure (ALF), which develops within days to weeks, and chronic liver failure (CLF), which evolves over months or years. Both forms can lead to serious complications such as jaundice, impaired detoxification, portal hypertension, ascites, multi-organ dysfunction, and coagulation disorders. A significant neuropsychiatric consequence of liver failure is hepatic encephalopathy (HE), a spectrum of cognitive, motor, and behavioral abnormalities.

Diagnostic Potential of Salivary Interleukin-8 mRNA and Protein in Oral Squamous Cell Carcinoma and Oral Potentially Malignant Disorders: Insights From South India.

Background Oral squamous cell carcinoma (OSCC) is a common type of head and neck cancer, which is often preceded by oral potentially malignant disorders (OPMDs). Though comprehensive examination forms the backbone of oral cancer screening, the combination of salivary proteomic and transcriptomic markers may identify molecular markers specific to OSCC and assess their ability to predict malignant transformation in OPMD. Hence, this study aimed to determine the diagnostic utility of salivary interleukin-8 (IL-8) mRNA and protein in the differential diagnosis of OSCC, OPMD, and healthy controls.

Enhancement of genetic gain for early seedling vigor traits through marker-assisted pedigree selection in rice ( L.).

Unlabelled: Early Seedling Vigor (ESV) is a critical trait for direct-seeded rice (DSR), as it promotes rapid seedling establishment and effective weed suppression. Enhancing ESV is therefore essential for developing varieties adapted to DSR conditions. This study aimed to accelerate genetic gain for ESV traits through Marker-Assisted Pedigree Selection (MAPS) by leveraging reported quantitative trait loci (QTLs).

Critical Role of Mg Ions in RNA Folding Transitions: Anchoring the A-Minor Twist in the SAM-II Riboswitch.

Magnesium ions (Mg) play a crucial role in stabilizing various RNA tertiary motifs, such as pseudoknots, G-quadruplexes, kissing loops, and A-minor motifs, to name a few. Despite their importance, the precise location and role of Mg ions in RNA folding are challenging to characterize both experimentally and computationally. In this study, we employ an all-atom structure-based model integrated with the dynamic counterion condensation (DCC) model to investigate the folding and unfolding transitions of apo SAM-II riboswitch RNA at physiological concentrations of Mg.

Supercooled Liquid Phases of Luminescent Zero Dimensional Metal Halide Hybrids.

Chemical design of metal halide hybrids (MHHs) with suppressed melting point () allows access to glassy phases from their liquid-melts. Thermal phase change (crystal-melt-glass) properties of glassy MHHs (with glass transition temperature > room temperature) have been exploited for device applications. However, room temperature stable supercooled liquid (SCL) MHHs (with < room temperature), originating from glass-SCL phase change, remain inaccessible.

The Conformational Landscape of AlphaFold2-Predicted Amyloidogenic Light Chains and Their Correlation With VL Domain Mutations and Aggregation Propensity.

Systemic light-chain amyloidosis (AL) is caused by the misfolding and aggregation of immunoglobulin light chains (LCs), which natively form homodimers comprising variable (VL) and constant (CL) domains in each monomer. High sequence variability, particularly within the VL domain, results in varied structural changes and aggregation propensities, making it challenging to develop broadly effective native protein stabilizers/aggregation inhibitors, as each AL patient carries a unique light chain. Using artificial intelligence (AI)-based AlphaFold2, known for its accuracy in modeling folded proteins, we generated an extensive repertoire of structural models of full-length LCs from four amyloidogenic germlines: IGLV1(λ1), IGLV3(λ3), IGLV6(λ6), and IGKV1(κ1), over-represented in AL patients to identify germline-specific structural features.

Essential role of clathrin and lipid rafts in pH-dependent entry of Chandipura virus: independence from caveolin pathway.

Chandipura virus (CHPV), a Rhabdoviridae family member, is an emerging neurotropic pathogen responsible for acute encephalitis outbreaks in children, mainly in India. Despite its public health relevance, the mechanisms underlying CHPV entry into host cells remain poorly understood. In this study, we used pharmacological inhibitors in Vero cells to dissect the virus's entry pathways.

Black Phosphorus Nanosheets as Efficient Ion Navigators at Room Temperature in Polyacrylonitrile-Based Composite Solid Polymer Electrolyte for Li-Ion Batteries.

Solid polymer electrolytes (SPEs) have garnered significant interest lately for all-solid-state batteries (ASSBs) because of their easy processability and flexibility; however, their low ionic conductivity has to be enhanced by forming composite polymer electrolyte (CPE). Herein, a polyacrylonitrile (PAN)-based triple-composite solid polymer electrolyte with black phosphorus nanosheets (BPN) and SiO nanoparticles (SO) is reported, which synergistically utilizes the efficient directed Li+ pathways (via BP) while reducing PAN crystallization (by SiO) and enhancing the dissociation of Li salts. Thus, an impressive ionic conductivity of 4.

Bright, Stable, and Active: Surface Engineered Blue-Emitting InP Quantum Dots for Photoinduced Charge Separation in Water.

Unique optoelectronic and surface properties of quantum dots (QDs) make them promising materials for several scientific explorations, especially in solar energy research. Understanding the dynamics of charge carrier separation and extraction is essential to enhancing the performance of QD-based light-harvesting devices. Herein, we investigate the photoinduced electron transfer (PET) process in blue-emitting QDs based on indium phosphide (InP)─the latest addition to luminescent materials.

Lactones as promising biofilm inhibitors: disrupting bacterial communication for Next-Gen therapies.

The rise of antibiotic-resistant bacteria and biofilm-related infections presents a significant challenge in modern medicine, necessitating the development of novel therapeutic strategies. Lactones, compounds that can mimic N-acyl homoserine lactones (AHLs), have the potential to disrupt quorum sensing (QS) in pathogenic biofilm-forming bacteria. In this study, we evaluated the antibacterial and antibiofilm properties of five different lactones--caprolactone, -decalactone, -decalactone, -octalactone, and -methyl decalactone-along with a lab-produced lactone from newly isolated strains, against and .

Quantitative Strategies for Decoding Organelle Ion Dynamics.

Ion dynamics within cellular organelles are fundamental to numerous biochemical processes, maintaining homeostasis and enabling critical cellular functions. Despite continuous ion movement across organelle membranes, stable ionic gradients are preserved, creating optimal microenvironments for organelle-specific activities such as ATP production in mitochondria, lysosomal degradation, Golgi-mediated protein modifications, and DNA processing in the nucleus. These gradients are regulated by specialized membrane proteins, including ion channels and transporters, which facilitate selective and controlled ion flux.

Multicomponent reactions (MCRs): an emerging toolbox for protein bioconjugation.

The bioconjugation of proteins is a powerful process that has tremendous applications in the fields of materials science and medicine. Multicomponent reactions (MCRs) provide an opportunity to conjugate at least two important molecules with a protein and furnish a versatile bioconjugate. In the last decade, bioconjugation chemistry has shown remarkable momentum with the involvement of different MCRs.

Foldamer engineering with squaramide and phenanthroline motifs: synthesis, characterisation, and structural insights.

We report a new class of phenanthroline-squaramide foldamers (1-3) that adopt robust, single-helical conformations in both solution and the solid state, stabilised by intramolecular hydrogen bonding and π-π stacking. Structural integrity was confirmed by single-crystal X-ray diffraction and NMR spectroscopy. Notably, the helical architectures are highly robust, displaying remarkable resistance to disruption by competitive solvents (, DMSO) and maintaining their structure at elevated temperatures (up to 85 °C), as confirmed by variable-temperature NMR studies.

TGF-β inhibitor SB431542 suppresses SARS-CoV-2 replication through multistep inhibition.

Unlabelled: The coronavirus disease 2019 (COVID-19) pandemic highlighted the critical need for broad-spectrum antivirals with high resistance barriers. Here, we demonstrate that SB431542, a selective TGF-β receptor I (ALK5) inhibitor, exhibits potent antiviral activity against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) through unprecedented multitargeted mechanisms. Through comprehensive , isothermal titration calorimetry, and analyses, we identified that SB431542 directly binds to SARS-CoV-2 ORF3a and disrupts its canonical function in inhibiting autophagosome-lysosome fusion.