Thiolysis of nitrobenzooxadizole (NBD)-piperazine motifs has been widely utilized for the development of hydrogen sulfide (H2S) probes and scavengers. Despite this prevalence, the selectivity of this important reaction remains underscrutinized because some NBD-based probes showed a certain fluorescence response toward sulfur dioxide (SO2). Herein, we present experimental and computational investigations for a deeper understanding of SO2 reactivity with different NBD-piperazine motifs and uncover new chemistries. We demonstrate that the reaction rates of SO2 with NBD piperazines are 2 orders of magnitude slower than those of H2S, thus underscoring high selectivity of the NBD-piperazine motifs for the development of H2S scavengers. We demonstrate that the incorporation of a positively charged group onto the NBD-piperazine motifs promotes fast and reversible formation of an NBD/SO2 supramolecular complex with a moderate binding constant. In addition, the positively charged microenvironment from cationic micelles also promotes the binding of NBD probes with SO2, resulting in a fluorescence response that may interfere in H2S detection. To address this limitation, we rationally designed a dual-NBD-caged probe to selectively sense H2S over SO2 and provided the first quantitative illustration of the improved selectivity for such a dual-caged strategy. Our work should offer valuable insights into the development of highly selective tools for reactive sulfur research.

A one-pot approach was developed for the direct synthesis of novel benzooxepino-fused tetrahydroquinoline-fused iminosugars via an intramolecular aza-Diels-Alder reaction mediated by an aryl iminium ion. The obtained multicyclic fused iminosugars were evaluated for their inhibitory activity against α- and β-glucosidases. The results showed that the iminosugars derived from l-ribose demonstrated significantly inhibitive activity against α-glucosidase, with IC50 values ranging from 2.77 μM to 6.12 μM. Kinetic analyses based on Lineweaver-Burk plots (1/V versus 1/[S]) indicated that compounds 3ba and 3bd act as rare uncompetitive inhibitors against α-glucosidase, with calculated Ki values of 10.50 ± 0.35 μM and 9.28 ± 0.31 μM, respectively.

Mitochondrial viscosity is a key parameter reflecting the functional status of mitochondria, and its dysregulation is linked to various diseases. In this study, we designed and synthesized two asymmetric heptamethine quinocyanine dyes (QCy7-1 and QCy7-2). QCy7-1 exhibits viscosity-activated fluorescence (λem = 780 nm; Stokes shift = 239 nm) and a 20.8-fold brightness increase in glycerol versus PBS. Probe QCy7-1 enables real-time monitoring of mitochondrial viscosity changes induced by nystatin, monensin, lipopolysaccharide, and starvation, and in vivo imaging of non-alcoholic fatty liver disease.

Systematic investigations into organophosphate esters (OPEs) in lake environments remain limited, particularly regarding cross-media migration. In shallow grass-type lakes, aquatic plants play a pivotal role in determining OPE fate. This study provides a novel perspective on the role of aquatic plants in OPE migration and fate using an optimized Water-Aquatic Organisms-Sediment Interaction Model and combined with a comprehensive screening strategy. In total, 39 OPEs were identified across 218 samples, including four level 3 tentative candidates newly detected in lake media. Chlorinated OPEs predominated, with tris(2,4-di‑tert‑butylphenyl) phosphate exceeding concentrations of traditional OPEs. Grid-based sampling approach and functional zone division revealed distinct spatial distributions of different OPEs. This study simulated the migration process of OPEs within the Water-Aquatic Organisms-Sediment Model and quantitatively analyzed the exchange fluxes between different media. The total input of OPEs into the lake via water flow was 1910 kg/y, with the largest input originating from the Xiaoyi River. The fluxes of OPEs transported to sediments, aquatic plants, and aquatic animals were 9.19 kg/y, 362 kg/y, and 0.47 kg/y, respectively. The significantly higher flux to aquatic plants than to sediments and aquatic animals indicates their key role in the migration and fate of OPEs. Bioaccumulation analysis demonstrated that Potamogeton pectinatus L. exhibits particularly strong accumulation capacity for OPEs. By integrating field measurements and model analysis, this study further explored the economic benefits of using aquatic plants for OPE remediation, suggesting that reed harvesting is a viable strategy for the control and management of OPEs in lake ecosystems.

Accelerated global climate change has profoundly altered ecosystems and pollutant dynamics, severely hindering the accurate assessment of ecological risks associated with organophosphate esters (OPEs) due to the limitations of conventional monitoring approaches. To address these challenges, we developed an integrative "environmentbiota-pollutant" framework, combining spatial statistics, machine learning, and structural equation modeling to elucidate OPE bioaccumulation in dragonfly larvae using a dataset comprising 6099 samples. The study reveals that dragonfly larvae exhibit pronounced spatial aggregation (Moran's I = 0.899-0.933) and exceptional bioconcentration capacity (mean log BAF = 3.63), surpassing traditional media. Through random forest modeling, nutrient salts (total phosphorus, total nitrogen, nitrate nitrogen) were identified as the primary drivers of OPE bioaccumulation in larvae, accounting for 25.22% of the variance, over three times greater than the contribution from direct aqueous OPE exposure (7.67%). Further analysis using partial least squares structural equation modeling demonstrated that warming enhances nitrate bioavailability (beta = 0.742), which subsequently promotes OPE accumulation in larvae (beta = 0.409). This finding indicates that climate-driven nutrient cycling is a more significant driver than aqueous OPEs concentration. As climate change continues to influence nutrient cycling and bioavailability, this integrative approach offers a robust framework for understanding and addressing the ecological risks associated with OPEs in an evolving environment.

This study is the first systematic investigation of the pollution characteristics, geographical distribution, land use impact, and source apportionment of tri-OPEs and di-OPEs in the sediments of Shandong section of Yellow River Basin. Both tri-OPEs and di-OPEs show elevated detection frequencies, indicating the ubiquity of tri-OPEs and di-OPEs in the Yellow River Basin. Tri-OPEs concentrations varied from 3.67 to 275 ng/g dw, which were relatively higher compared to the concentrations of di-OPEs (ranging from 3.61 to 95.3 ng/g dw). The geographic distribution of tri-OPEs and di-OPEs exhibited significant spatial heterogeneity, with tributaries like the Dawen River showing notably higher concentrations than the main stem of the Yellow River. Industrial and agriculturally intensive areas showed significantly higher concentrations of tri-OPEs and di-OPEs than other regions, highlighting the key influencing factors of industrial and agricultural activities on the pollution levels of tri-OPEs and di-OPEs in the Shandong section of the Yellow River Basin. Utilizing a forward matrix factorization model, industrial emissions, agricultural production, atmospheric deposition, and domestic sewage were identified as the primary pollution sources of OPEs within this region. This study provides a scientific basis for managing the environment and controlling pollution from OPE compounds in the Yellow River Basin of Shandong section.

A series of diverse 2,3-dihydroquinazolin-4(1 H )-one- or imidazolidin-4-one-fused iminosugars were synthesized under different acid/base conditions, via a key iminium ion derived from Ts/Ms-activated saccharides and aminoamide derivatives.

Near-infrared (NIR) phosphor-converted light-emitting diodes have been widely applied in biomedical imaging, night-vision security surveillance, and nondestructive inspection. Owing to its natural abundance, low cost, and environmental benignity, Fe3+ is regarded as a promising activator for the development of broadband NIR phosphors. However, related studies remain relatively limited. In this study, an Fe3+-activated Sr2Sc2B4O11 phosphor is successfully synthesized. Under excitation at 353 nm, the phosphor exhibits broadband NIR emission covering the range of 800-1400 nm, with an emission peak centered at approximately 956 nm, a full width at half maximum (FWHM) of 183 nm, and an internal quantum efficiency of 34%. Furthermore, Yb3+ co-doping is introduced to construct an energy transfer system to enhance the optical performance. The energy transfer interaction between Yb3+ and Fe3+ not only significantly improves the thermal stability but also increases the internal quantum efficiency to 75.5%. In addition, NIR pc-LED devices fabricated using the Sr2Sc2B4O11: Fe3+ phosphor demonstrate promising application potential in venous imaging, night-vision security surveillance, information encryption, and nondestructive inspection.

This study focused on the pollution characteristics, influencing factors, and source apportionment of organophosphate triesters (tri-OPEs) and diesters (di-OPEs) in the plastic greenhouses soils with cultivation periods ranging from 6 to 32 years. The concentrations of Σ13tri-OPEs and Σ5di-OPEs in soil samples ranged from 39.60 to 730.52 ng/g dw and 2.25–6.94 ng/g dw, respectively. Tris (chloroethyl) phosphate was the predominant tri-OPE, while dibutyl phosphate was the most abundant di-OPE. The levels of OPEs pollution increased with the age of mulch film, highlighting the impact of the duration of mulch film usage on OPE accumulation. The type of fertilizer significantly impacted OPE levels. Soil samples treated with compound fertilizers showed the highest concentration of tri-OPEs, reaching up to 205.32 ng/g dry weight. In contrast, the highest concentration of di-OPEs was found in soil samples treated with water-soluble fertilizers, with a peak of 3.89 ng/g dry weight. Total organic carbon, pH, total nitrogen, and total phosphorus had minimal effect on OPEs levels. According to the Positive Matrix Factorization Model, the primary sources of OPEs included the use of pesticides, food packaging materials, and small-scale machinery (48.39 %), water and reclaimed water irrigation (17.68 %), the utilization of agricultural films (17.39 %), and atmospheric deposition and degradation processes (16.54 %). Compared to the moderate risks associated with compounds such as tri-2-ethyl phosphate, 2-ethylhexyl diphenyl phosphate, and tris(1-chloro-2-propyl) phosphate, tris(chloroethyl) phosphate exhibited a higher risk level in soil samples. This study offers insights into the potential risks linked to OPE contamination in agricultural soils.

A series of semi-saturated fused polycyclic iminosugars were synthesized by one-pot stereoselective three-component reactions of D-ribose tosylate, aniline and cycloenones under heating conditions. The N-aryl enamine derived from an iminium ion is the key intermediate for the reaction. In this way, various novel complex fused iminosugars were obtained through a normal Diels-Alder mechanism at 80 degrees C. This strategy will enable the preparation of bioactive iminosugar analogues with structural diversity.

This study utilized a comprehensive screening strategy to thoroughly investigate the species-specific distribution and tissue-specific distribution of potential organophosphate esters (OPEs) in 15 species of wild freshwater fish (n = 109). A total of 26 OPEs were identified, with tris(2-butoxyethyl) phosphate being the predominant OPE. The concentrations of OPEs ranged from 7.80 to 495 ng/g wet weight. No direct correlation was observed between OPE levels and fish body size. Feeding habits play a significant role in the accumulation levels of OPEs in fish species. Carnivorous fish exhibited the highest mean OPE concentration, followed by omnivorous fish, with herbivorous fish having the lowest concentration. Among all tissues and organs of fish, the brain exhibited the most elevated concentration of OPEs. The health risk assessment across all age groups based on Monte Carlo simulations revealed that children were at a high risk of exposure to OPEs through the consumption of wild freshwater fish.

β-Glucosidase (β-Glc) is widely expressed across various organisms and plays essential roles in physiological processes. Notably, β-Glc serves as a diagnostic marker for certain diseases and represents a potential therapeutic target. Developing tools for detecting β-Glc activity and discovering novel β-Glc inhibitors holds significant potential. In this study, we designed and synthesized a novel fluorescent probe named P1, utilizing resorufin as the fluorophore. This probe demonstrates exceptional selectivity, sensitivity (LOD = 8.2 × 10-5 U/mL), and affinity (Km = 7.59 μmol/L) towards β-Glc. It enables efficient imageing of β-Glc in living cells and has been successfully applied for screening inhibitors. Using this probe, a novel tricyclic benzimidazole azasugar inhibitor for β-Glc was identified. Overrall, the developed probe represents a powerful tool for β-Glc activity detection and inhibitor screening.

The homeostasis of various organelles within cells is essential for maintaining cellular functions. Designing fluorescent probes with organelle-targeting capabilities is a significant challenge. Mitochondria and lipid droplets (LDs) are two critical organelles. We have designed and synthesized four triphenylamine-based fluorescent probes (1-4), each incorporating D-pi-A and pyridinium salt structures, yet exhibiting distinct properties. Probe 1 and 2 demonstrate specific responses to viscosity, while probe 3 exhibits a pronounced response to polarity. Both probe 2 and 3 possess favorable cell membrane permeability and excellent photostability. Bioimaging results demonstrate that probe 2 and 3 selectively target LDs and mitochondria, respectively. Ultimately, probe 2 was employed to trace the dynamics of LDs within cells, while probe 3 was utilized to visualize mitophagy processes.

A metal‐free method is developed for the synthesis of N‐arylated lactam‐type iminosugars using hydrogen peroxide (35% in water) as an oxidant. The reaction of various α‐amino carbonyl compounds is performed in methanol, and the active methylene adjacent to the carbonyl group is rapidly removed to form a carboxylic acid as the key intermediate through a cascade radical cleavage reaction. Following an intramolecular amidation reaction, a series of N‐arylated lactam‐type iminosugars are prepared in satisfactory yields, providing an alternative protocol for the synthesis of such bioactive iminosugars. Additionally, several 4‐aminobutanamide derivatives are obtained by intermolecular amidation of the carboxylic acid intermediate.

Lipid droplets (LDs) are highly dynamic organelles that play crucial roles in various physiology processes, and their excessive accumulation is closely associated with nonalcoholic fatty liver disease (NAFLD). Therefore, the rational design of fluorescent probes for LDs detection is of significant importance. Inspired by dicyanomethylene-4H-pyran-based dyes, we designed and synthesized three pyridine malonitrile-based fluorescence probes (PMs). Among them, PM-3 exhibited a pronounced polarity-dependent fluorescence behavior, displaying strong fluorescence exclusively in low-polarity solvents such as toluene and dioxane. Moreover, PM-3 demonstrated excellent chemical stability and photostability, with an excitation wavelength compatible with the commonly used 488 nm laser. This probe can precisely label LDs and enable real-time monitoring of their dynamic Behavior in living cells. More importantly, PM-3 showed promising performance in distinguishing fatty liver tissue from normal tissue through fluorescence imaging. Taken together, PM-3 serves as a highly effective fluorescent tool for investigating the functional roles in LDs.

Changes in viscosity can significantly influence the functionality of the endoplasmic reticulum (ER), and viscosity-responsive fluorescent probes can provide valuable feedback on its physiological state. In this study, three multirotor-based fluorescent probes (1-3) were designed and synthesized. Probes 1 and 2 exhibited remarkable viscosity sensitivity and specific targeting ability towards the ER. Probe 1 was utilized for in situ dynamic visualization of ER viscosity changes during inflammatory responses, drug treatments, and reticulophagy.

A simple and effective synthesis method has been developed through Mannich and transannular reaction mechanisms to convert iminosugar C-coumarinyl glycosides 4a into cis-bicyclic γ-lactam derivatives 8a. The adaptability of this method has been demonstrated through various substituted coumarins, tosylated sugars, and amines. The extension reaction proved the plasticity of the bicyclic skeleton. In addition, this reaction has the characteristics of simple operation, a high yield, and high atomic economy.

In the presence of Hantzsch ester and with JohnPhosAuCl/AgOMs as catalysts, a series of indole-fused iminosugars were obtained in good yields by the intramolecular reductive coupling reaction of iminosugar C-glycoside, in which the terminal alkyne could be coupled with indole and further reduced to methyl. The substrates of iminosugar C-glycosides were conveniently prepared by a three-component reaction of tosylated/mesylated sugar, propargylamine, and indole derivatives. The advantages of this protocol are its simplicity and efficiency in constructing the complex indole-fused iminosugars.

Birefringent material serves as a cornerstone in photonic applications, including optical communications, polarization control, and laser technologies. The development of birefringent materials with large birefringence (Δn > 0.3) and short ultraviolet (UV) cut‐off edge (λcut‐off edge < 400 nm) remains a significant challenge. Here, we demonstrate that properly aligned expanded π‐conjugated groups provide a solution to balance the birefringence and UV transmittance. We report a new birefringent material, Li3(C9N13)·6H2O (LCN), in which the Li atoms and water molecules act as linkers to connect the birefringence‐active group [C9N13]. This crystal material exhibits a giant optical anisotropy (Δnexp = 1.031 @ 546 nm), which is one of the highest among bulk crystal materials known to date. In addition, LCN shows a band gap of 3.62 eV, indicating its applicability in the UV optical range. Owing to favorable Li cation linkers and hydrogen bonding, the [C9N13] groups achieve a perfectly coplanar arrangement, thereby maximizing the optical anisotropy. This work offers a novel strategy for the rational design of advanced birefringent materials.