The development of efficient, non-noble metal catalysts to implement the in-situ hydrogen donor strategy is driven by the high cost and safety risks associated with external H2 supply, and this issue merits considerable attention. In this study, an atomically dispersed Ni/Nb2WO8 catalyst was synthesized by employing a hydrothermal method, with ammonium carbonate, ammonium oxalate, and urea comparatively evaluated as templating agents. Among them, the ammonium carbonate template endowed the Nb2WO8 support with the highest specific surface area and oxygen vacancy concentration, thereby achieving superior performance. Optimizing the reduction temperature to 350 degrees C modulated the Ni species to generate synergistic single-atom Ni2+ and Ni0 nanoparticle active sites, along with oxygen vacancies and Lewis acid sites. Realized through this structure, in situ H delta- production via isopropanol reforming and the water-gas shift reaction facilitates the cleavage of the beta-O4 bond in lignin without external H2. The yield of aromatic monomers from lignin depolymerization reached 41.07 wt% under optimized conditions, which significantly exceeds that of commercial Pd/C. Upon H2 reduction, the catalyst achieves efficient regeneration and sustains good cyclic stability. This work establishes the template-tuned Nb2WO8 support with Ni0/Ni2+ synergy as an effective strategy for external H2-free lignin valorization using non-noble metal catalysts.

Herein, we report an efficient and simple strategy to access diverse chiral-at-sulfur(VI) Brønsted acids. Sulfonimidoyl chlorides or fluorides react with sulfonamides with inversion of configuration, producing chiral-at-sulfur sulfonimidamides containing an acidic NH group. Similarly, reactions of sulfonimidoyl chlorides with corresponding sulfonimidamides give access to C2-symmetric chiral-at-sulfur Brønsted acids. Finally, attaching sulfonimidamides to a 1,1-bi-2-naphthol (BINOL)-derived phosphoryl chloride scaffold generates Brønsted acids combining sulfur-centered point chirality with BINOL axial chirality.

Sustainable aquaculture of grass carp (Ctenopharyngodon idella, GC) is consistently threatened by bacterial diseases, particularly those caused by Aeromonas veronii. A disease-resistant grass carp (DR-GC) has been developed by backcrossing female gynogenetic GC with normal male GC, exhibiting improved resistance. However, the systemic molecular mechanisms of DR-GC defending against Aeromonas veronii infection remain largely unexplored. Here, a label-free quantitative proteomics approach was employed to systematically compare proteomic profiles across five tissues (intestine, liver, muscle, skin, and kidney) in DR-GC and GC under healthy and infected conditions. The intestine was identified as the central defense tissue, exhibiting the highest number of differentially abundant proteins (DAPs). In DR-GC, A0A3N0YEK7 (small ribosomal subunit protein eS28), A0A3N0YGT8 (ATP synthase-coupling factor 6) and A0A3N0YNS7 (apolipoprotein A-I) were significantly upregulated in intestine, while D5KZW6 (GCHV-induced protein), A0A3N0Z0A1 and Q8JH84 (hemoglobin subunit alpha) were significantly dysregulated across multiple tissues, which playing the critical roles in defense mechanisms at the protein level. Furthermore, cytochrome P450-associated pathways, cytosolic DNA-sensing and RIG-I-like receptor signaling pathways were identified as crucial coordinators mediating immune and metabolic responses. This study provides the first comprehensive proteomic view of multi-tissue defense mechanisms in DR-GC, and identifies key DAPs and pathways for subsequent functional validation.

Cascade metathesis polymerization serves as a powerful method to synthesize well-defined polymers with increased structural complexity. Despite recent advances, achieving a sequence-regulated cascade metathesis polymerization of monomers with functional groups that exhibit high metathesis reactivity remains a formidable challenge. Here, we report an asymmetric, cascade ring-opening/cross metathesis polymerization of monomers containing highly ring-strained cyclopropene and highly reactive terminal alkene. The major hurdle lies in the fact that the precision control over the alternating sequences would be compromised by homopolymerization or homodimerization of the two reactive alkenes. By leveraging the 14-electron, chiral cationic Grubbs-type catalyst, both the initiation and chain growth processes include catalytic cycles orchestrated by two sequential metathesis reactions: ring-strain-driven ring-opening metathesis with cyclopropene and subsequent chelation-controlled cross metathesis with terminal alkene. This cascade metathesis polymerization is also characterized by high stereoselectivity, providing polymers with all-cis alkenes and good enantioselectivity at the recurring quaternary stereocenters.

Isolongifolanone, a natural product, offers several advantages over traditional small organic molecules, including excellent biocompatibility, high reactivity, low cytotoxicity, affordability, and environmental friendliness. While numerous compounds derived from isolongifolanone have been developed, most research has focused primarily on its antitumor properties, with limited exploration of its potential applications as a fluorescent probe. In this study, we designed and synthesized a series of novel natural small-molecule fluorescent probes based on isolongifolanone, utilizing pyrazole compounds as the fluorophore, vanillin or p-hydroxybenzaldehyde as the linker, and levulinate as the sulfite-specific recognition group. The probes react with sulfite through a nucleophilic addition reaction, resulting in a strong fluorescence signal, demonstrating high sensitivity and good selectivity for sulfite detection. Quantitative detection of sulfite can thus be achieved by monitoring the fluorescence intensity. The chemical structure and reaction mechanism of the fluorescent probes were characterized using NMR, LC-MS, and HRMS. Additionally, the isolongifolanone-based fluorescent probes were successfully applied for the detection of sulfites in tumor cells, significantly broadening the application scope and value of isolongifolanone.

Protein coextraction often compromises the purity and reproducibility of crude polysaccharide preparations from complex food-derived matrices. Using crude rice bran polysaccharide hot-water extract, we developed a rapid adsorption-based deproteinization strategy using iron(III) phosphate tetrahydrate (FePO4 & centerdot;4H2O). FePO4 & centerdot;4H2O remained effective across pH and ionic strength variations. Under optimized conditions, FePO4 & centerdot;4H2O removed approximately 98% of protein while maintaining more than 85% polysaccharide retention, and protein removal approached a near-plateau within 1 min under the tested conditions. The observed pH and ionic strength trends suggest that adsorption was not governed solely by electrostatic attraction. Compared with conventional deproteinization methods, this one-step treatment improved the balance between protein removal and polysaccharide preservation. FePO4 & centerdot;4H2O treatment also reduced phytic acid (PA) in the polysaccharide fraction from 0.36 +/- 0.02 to 0.12 +/- 0.01 g kg-1, indicating additional purification value in the rice bran system examined here. Overall, this rapid pretreatment provides a practical route to improve the preparation quality of food-derived polysaccharide samples.

Ultraviolet (UV) irradiation of sperm is widely used to genetically inactivate the paternal genome and thereby induce gynogenesis in teleosts, yet the mechanistic basis linking irradiation dose to developmental outcomes remains poorly understood. Here, we used UV-irradiated mirror carp (Cyprinus carpio var., MC) sperm to activate grass carp (Ctenopharyngodon idella, GC) eggs and evaluated dose-dependent changes in sperm ultrastructure and subsequent embryonic performance. Transmission electron microscopy revealed pronounced disruption of sperm mitochondrial ultrastructure at 4000 mJ/cm2, which was accompanied by markedly reduced mitochondrial DNA (mtDNA) integrity as assessed by long-range PCR. Notably, this dose produced the highest hatching rate of gynogenetic larvae (12.1%). Higher UV doses further aggravated mitochondrial damage and were associated with a sharp decline in gastrulation success. Metabolomic profiling focused on mitochondrial energy metabolism revealed pronounced metabolic dysregulation in embryos activated by UV-irradiated sperm during the gastrula stage, most prominently manifested as a severe depletion of NAD+. Notably, NAD+ levels rebounded at the somite stage. This stage-dependent fluctuation was closely associated with gastrulation arrest and increased embryonic mortality. Collectively, these results indicate that an optimal UV dose window, together with the maintenance of embryonic mitochondrial energy homeostasis, is a key determinant of successful gynogenesis, providing a metabolic perspective for optimizing gynogenesis protocols in aquaculture breeding.

BACKGROUND:Thallium, a highly toxic heavy metal, is widely distributed in the environment. The substance poses a grave threat to human health through contamination of the food chain, drinking water, and environmental exposure. Consequently, the monitoring of thallium levels, particularly in water, is of critical importance. In this study, a novel analytical method was developed for the direct quantification of thallium ions (Tl+) in aqueous samples. This method is based on the specific supramolecular interaction between cryptand[2.2.2] and Tl+, and it utilizes electrospray ionization tandem mass spectrometry (ESI-MS/MS). RESULTS:The method demonstrated remarkable analytical performance, exhibiting a linear range of 2.5 to 100 μg/L (R2 > 0.999), a limit of quantification (LOQ) of 2.5 μg/L, and a limit of detection (LOD) of 0.8 μg/L. The recovery rates exhibited a range from 88.65% to 118.09%, with relative standard deviations (RSD) falling below 10%, thereby affirming the attainment of satisfactory accuracy and precision. It is noteworthy that this method necessitated only 5 μL of sample and did not require any preliminary separation steps. Despite the inhibitory effects exhibited by complex sample matrices, these effects were effectively mitigated through a straightforward dilution strategy. The method was successfully applied to the analysis of 66 real-world environmental water samples. SIGNIFICANCE:This work presents a novel tool that enables rapid and reliable detection of Tl+ in water samples. Compared with traditional ESI methods for heavy metals, the application of cryptand[2.2.2] makes the developed method more selective and sensitive, since it has strong binding ability and selective to Tl+ ion. The study introduces a novel design concept and practical application for the development of supramolecular recognition-based ESI-MS methods for metal ion analysis. These methods hold significant potential for environmental monitoring and related fields.

We report for the first time the combination of directed evolution focused on enhancing and reversing the stereoselectivity of an enzyme with Cu(I)-mediated click chemistry (CuAAC), providing an asymmetric click approach for versatile chiral triazoles products. In this study, the halohydrin dehalogenase HheG was used as the enzyme which was evolved to induce a stereoselective ring-opening reaction of cyclic epoxides in the presence of NaN3 with the formation of chiral azido products. Two mutants of opposite stereopreference were generated, which convert cyclohexene oxide as well as cycloheptene oxide to (1S, 2S)-2-azidocyclohexanol, (1R, 2R)-2-azidocyclohexanol, (1S, 2S)-2-azidocycloheptanol and (1R, 2R)-2-azidocycloheptanol with essentially high stereoselectivity. The chiral products were then subjected to CuAAC in reactions with structurally different alkynes. Since HheG was found to be compatible with Cu(I), the process was also performed successfully in a unique 2-step one-pot process leading to various chiral triazoles. In order to understand the enhancement and reversal of the evolved enantioselectivity, QM and MD computations were performed. This approach harnesses the modifiability and high stereoselectivity of the evolved biocatalysts in combination with click chemistry. It holds great potential for diverse fields, particularly in the area of pharmaceuticals.

Stable isotope-labeled internal standards (SIL-IS) are the gold standard for liquid chromatography-tandem mass spectrometry (LC-MS/MS) quantification in complex biological matrices. Their application can be limited by synthetic complexity, high cost, and the lack of commercially available labeled standards for many bioactive analytes. Here, we establish and evaluate an internal-standard strategy based on hydrogen-deuterium exchange (HDX)-derived deuterated isotopologue mixtures. Using Pd/C, Pt/C, and AlCl₃ catalytic systems, deuterated isotopologue mixtures (d₁-dₙ) of eight structurally diverse bioactive compounds were prepared by HDX in deuterated methanol and characterized by ¹H NMR and LC-MS. Isotopologues with a mass difference of Δm ≥ 3 were selected as internal-standard candidates to minimize overlap with analyte M + 1/M + 2 isotopic peaks. Isotopic-distribution screening and chromatographic evaluation showed that eligible d₃-dₙ isotopologues co-eluted with their corresponding analytes (Δt < 0.01 min), with no appreciable chromatographic isotope effect (CIE). In plasma, LC-MS/MS validation showed linearity over 1-500 ng/mL (R² ≥ 0.995), limits of detection of 0.003-0.080 ng/mL and limits of quantification of 0.01-0.25 ng/mL. Trueness ranged from 85% to 115%, while precision, expressed as relative standard deviation (RSD), was ≤8% intra-day and ≤12% inter-day. Ratio-based matrix effect (ME%) values ranged from 85% to 112%. Using clenbuterol hydrochloride as a model analyte, the isotopologue-mixture-derived internal standard showed calibration performance comparable to that of the commercial deuterated standard clenbuterol-d₉. Compared with quantification based on external calibration without internal-standard normalization, the proposed approach reduced quantitative deviation from 15 to 25% to <8%. Overall, the results support HDX-derived isotopologue mixtures as practical internal-standard sources and establish a selection-and-validation framework for LC-MS/MS quantification when commercial SIL-IS are unavailable.

Phytic acid (PA), owing to its strong acidity and multidentate metal-chelating properties, readily forms multiple adduct/complex ions in mass spectrometry and is prone to pronounced matrix effects, resulting in complicated spectra and compromised sensitivity and quantitative robustness, which poses a major challenge for rapid and accurate PA quantification. Herein, we developed a rapid quantitative method for PA based on trimethylsilyldiazomethane (TMSD) methyl-ester derivatization coupled with paper spray mass spectrometry (PS–MS). PA was derivatized with TMSD to yield the methylated product (PA-Me), and the derivative solution was purified via “post-derivatization nitrogen blow-down followed by water reconstitution”, thereby markedly reducing background interference. In positive-ion mode, the stable sodium adduct ion [PA-Me+Na]+ (m/z 851.04) was used as the quantifier, enabling fast quantification with selected ion monitoring (SIM). PS–MS was performed with a 15 μL spotting volume and methanol/water (90/10, v/v, containing 0.1% formic acid) as the spray solvent, allowing rapid analysis without chromatographic separation. The method exhibited good linearity over 0.125–30 μg/mL (R2 ≥ 0.9965), with a limit of detection (LOD, S/N = 3) of 0.080 μg/mL and a limit of quantification (LOQ, S/N = 10) of 0.270 μg/mL. The intra-day and inter-day precision values were both < 10% (RSD), and recoveries ranged from 87.2% to 122.4%. This LC-free strategy features low solvent consumption and high analytical throughput, and was validated using rice bran protein and rice bran polysaccharide samples, providing technical support for rapid screening and quality control of PA in complex food/plant matrices.

Protein-flavor interactions strongly influence the sensory quality of plant-based foods. However, rapid methods for comparing binding behavior under controlled dynamic conditions remain limited. In this study, an inverse liquid chromatography (ILC) method was developed to investigate interactions between six aldehydes (pentanal to decanal) and soy protein isolate (SPI). An SPI-based stationary phase was prepared by physically mixing SPI with diol-functionalized silica to provide mechanical bed stability. Flavor retention provided insights into binding percentages, thermodynamic parameters, and adsorption mechanisms. Binding increased with aldehyde chain length, reaching up to 96%. The ΔG for pentanal to octanal ranged from -17.0 to -26.0 kJ·mol-1, indicating spontaneous and chain-length-dependent interactions. Thermodynamic analysis revealed a shift from enthalpy-driven binding for short-chain aldehydes to entropy-driven binding for longer chains, highlighting the contribution of hydrophobic effects. Adsorption followed a Henry type isotherm. ILC provides a rapid and complementary approach for probing protein-flavor adsorption behavior in plant-based protein systems.

MN-Suite is an open-source, locally deployable molecular networking toolkit developed through LLM-assisted software engineering to provide a flexible, server-independent workflow for natural product MS/MS analysis. The toolkit integrates six similarity algorithms and three spectral modes (MS2, neutral loss (NL), and hybrid MS2+NL), offering a customizable GUI-based framework for local preprocessing, network construction, and visualization. In the Aconitum data set examined here, the neutral-loss entropy-similarity strategy (NL-ES) produced the highest internal RCF score among the tested algorithm-data combinations (RCF = 0.537). By combining diagnostic-ion/neutral-loss filtering with a seed-neighborhood strategy, the MN-Suite prioritized 26 putative alkaloid analogues for further structural confirmation. These results support MN-Suite as a practical local workflow for configurable molecular networking and illustrate how domain experts can use LLM-assisted software engineering under human oversight to develop specialized computational tools.

C-prenylated flavonoids possess notable pharmaceutical potential, but their production is hindered by the challenging selective prenylation of their unstable polyphenolic cores. Natural prenyltransferases offer a direct route but suffer from low activity and incomplete mechanistic understanding. Here, we report a directed evolution strategy to reshape the active pocket of the prenyltransferase AtaPT, uncovering an aromatic cage that governs both regioselectivity and donor specificity. By tuning cage occupancy, we engineer three mutants with high chemo- and regioselectivity toward dimethylallyl diphosphate or geranyl pyrophosphate. Structural analysis and molecular simulations validate the role of the cage in guiding flavonoid prenylation. Notably, the aromatic cage mechanism observed in AtaPT is not unique and can be recapitulated in homologous enzymes. Introduction of the aromatic cage consistently enhances both activity and selectivity, confirming its crucial role. AtaPT mutants enable the efficient and scalable synthesis of 27 C-prenylated flavonoids, including 8 previously unreported compounds. With an integrated donor regeneration system, preparative-scale biotransformations achieve product titers up to 400 mg/L. This study establishes a selective and scalable biocatalytic platform for flavonoid prenylation and offers mechanistic insights for enzyme engineering.

Selective deuteration of (hetero)aryl rings is of great significance and interest, yet it has remained a challenge, especially when employing D2O as deuterium source. Herein, the selective desulfurative deuteration of widely available (hetero)aryl sulfides with D2O (mostly 1.5 or 3.0 equiv.) has been established by nickel catalysis. This strategy affords an efficient and robust route for the synthesis of a wide range of deuterated (hetero)arenes (87 examples, > 10 different heterocycles) in generally good yields and high deuterium incorporation with good functional group compatibility. The catalytic reaction could be applied to scaled-up synthesis (e.g., 6.4 g for product 2, 0.1 mol% Ni catalyst, 590 TON) and late-stage deuteration of various drugs and bioactive molecules.

The synthesis of sequence‐defined oligomers with a high molecular weight has remained a challenge due to the lack of effective coupling methods, reduced reactivity and/or selectivity with increasing oligomer lengths, and poor solubility of suitable reactants and/or resulting macromolecules. Contributing to overcome these limitations, a room‐temperature method for the construction of sequence‐defined oligo‐sulfonimidates via sulfur‐phenolate exchange (SuPhenEx) reactions using an exponential growth strategy is reported. This method enables the efficient and rapid synthesis of sequence‐defined oligo‐sulfonimidates, up to a 16 mer (Mw = 6.5 kDa). Next, the versatility of this method is demonstrated by synthesizing a sequence‐defined tetramer with four nonrepeating building blocks, and fusing it with the 16 mer by another SuPhenEx reaction, resulting in a sequence‐defined 20 mer (66% isolated yield; Mw = 8.5 kDa). To the authors' best knowledge, this is the longest S(VI)–O‐linked sequence‐defined oligomer constructed to date. Given the flexibility of the route, constantly high yields of the SuPhenEx coupling, independent of the oligomer length, and the enantiospecific nature of SuPhenEx reactions on chiral species, this approach for the synthesis of sequence‐defined oligo‐sulfonimidates paves the way for further exploring the structure‐property relationships of sequence‐defined oligomers and other S(VI)‐O‐linked materials.

Gate residues, acting in concert with distal dynamic networks, are emerging as critical yet underexploited regulators of enzymatic catalysis. Here we show that conformational dynamics analysis of fluoroacetate dehalogenase RPA1163 reveals a gate-based allosteric pair (K181-W185) that governs substrate access and reactivity. Network engineering of this pair yields a double mutant with high turnover number for α-fluorophenylpropionic acid (turnover number > 2 × 10⁵), establishing gate-centric allostery as a generalizable design principle. Structural and molecular dynamics analyses show that the activity enhancement arises from stabilization of catalytically competent open states through long-range coupling. Extension of this strategy to three additional dehalogenases confirms the universality of gate-based dynamic rewiring. Leveraging this framework, we establish a robust biocatalytic platform for stereoselective synthesis of α-fluoro and α-hydroxy carboxylic acids, achieving high productivity (turnover number > 3.7 × 10⁶) and enabling decagram-scale preparation of pharmaceutically relevant intermediates with high yield and enantioselectivity. Together, these findings establish gate-residue allostery as a powerful concept in protein engineering, bridging conformational dynamics with translational biocatalysis.

Chiral materials, which can manipulate the electron spin by the chiral-induced spin selectivity (CISS) effect without involving the complicated magnetic components, exhibits great potentials in low-cost spin optoelectronics. However, ideal CISS usually requires a relatively ordered and conductive (or insulated but ultrathin) chiral layer, which contradicts the disordered-packing and high-impedance characteristics of chiral molecules, preventing the direct application of most chiral molecules for CISS and increasing the difficulty to prepare chiral spin-selective layers. Here, a general disordered and conductive chiral molecular strategy is proposed to simply construct the small-molecule-based spin polarizer. Directly spin-coating chiral molecules onto the electrode forms the disordered chiral thin film, which exhibits obvious CISS effects demonstrated by an electrochemical oxygen evolution reaction (OER) and a magnetic conductive probe-atomic force microscopy (mcp-AFM). More importantly, by disorderly doping conductive graphite nanoparticles into this film, the high impedance of the chiral molecular layers can be effectively reduced, which results in a higher OER activity with lower H2O2 byproduct and a stronger spin-polarization degree. This can be attributed to a conductivity-enhanced disordered CISS effect, which may lay the foundation for designing universal and high-performance spintronic devices.