Diverse Functional Groups Research Articles

Local Community Assembly Mechanisms and the Size of Species Pool Jointly Explain the Beta Diversity of Soil Fungi

Fungi play vital regulatory roles in terrestrial ecosystems. Local community assembly mechanisms, including deterministic and stochastic processes, as well as the size of regional species pools (gamma diversity), typically influence overall soil microbial community beta diversity patterns. However, there is limited evidence supporting their direct and indirect effects on beta diversity of different soil fungal functional groups in forest ecosystems. To address this gap, we collected 1606 soil samples from a 25-ha subtropical forest plot in southern China. Our goal was to determine the direct effects and indirect effects of regional species pools on the beta diversity of soil fungi, specifically arbuscular mycorrhizal (AM), ectomycorrhizal (EcM), plant-pathogenic, and saprotrophic fungi. We quantified the effects of soil properties, mycorrhizal tree abundances, and topographical factors on soil fungal diversity. The beta diversity of plant-pathogenic fungi was predominantly influenced by the size of the species pool. In contrast, the beta diversity of EcM fungi was primarily driven indirectly through community assembly processes. Neither of them had significant effects on the beta diversity of AM and saprotrophic fungi. Our results highlight that the direct and indirect effects of species pools on the beta diversity of soil functional groups of fungi can significantly differ even within a relatively small area. They also demonstrate the independent and combined effects of various factors in regulating the diversities of soil functional groups of fungi. Consequently, it is crucial to study the fungal community not only as a whole but also by considering different functional groups within the community.

Ligand‐promoted dehydrogenative coupling of γ‐/β‐amino alcohols with ketones to N‐heterocycles via molybdenum catalysts

Molybdenum‐based efficient and broadly applicable catalytic system is presented for the dehydrogenative coupling of γ‐/β‐amino alcohols with ketones. In particular, complex Mo(CO)6 in combination with Xantphos and t‐BuOK as base provides direct synthesis of structurally diverse quinoline, pyridine, and pyrrole compounds (total 55 examples) with isolated yields up to 92%. Low catalyst loading, cost‐effective, and high catalytic activities with high tolerance to stand with diverse functional groups are additional features of these molybdenum catalysts exhibiting high efficacy to replace the precious metal catalysts such as ruthenium and iridium. Furthermore, the DFT and experimental studies were explored for the reaction mechanism which can assist in broadening the scope of the molybdenum catalysts for different transformation reactions.

Silk Sericin is a Potent, Multifunctional Biomaterial for Endothelialization of Tissue‐Engineered Heart Valves

AbstractEndothelialization is important for offering an anticoagulant surface, which is crucial for the construction of tissue‐engineered heart valves. Silk sericin is extensively investigated in the biomedical field due to its remarkable biological activities and diverse functional groups, favoring chemical modifications for the formation of versatile constructs. Herein, a sericin covalently modified valve (SCMV) is successfully fabricated by coupling maleylated silk sericin (MSS) with thiolated decellularized heart valve (DHV) through a Michael addition reaction. The results demonstrate that SCMV exhibits a smooth surface, higher hydrophilicity, and excellent resistance to platelets adhesion compared to DHV. Additionally, SCMV promotes endothelial cells (ECs) adhesion under both static and flow conditions and enhances their survival in a mouse subcutaneous implant model. The study also discovered that MSS‐stimulated ECs exhibit increased RhoA activation, expression of rho‐associated protein kinase 2 (ROCK2) and phosphorylated myosin light chain 2 (MLC2), actin polymerization, and cell adhesion; whereas actin organization and cell adhesion are significantly reduced by treatment with Y‐27632, a ROCK inhibitor. Furthermore, several integrin subunits, including α1, α2, α3, α5, α6, β1, β3, and β5, are involved in this regulatory process. Collectively, the findings highlight the potential application of silk sericin in promoting endothelialization of DHV while uncovering novel mechanisms underlying its regulatory effect on ECs adhesion.

Metal-Free Radical [3 + 2] Annulation of Tetraalkylthiuram Disulfide with Alkynes/Alkenes: An Approach of Synthesizing 1,3-Dithiole and 1,3-Ditholane Derivatives.

A novel and metal-free [3 + 2] annulation of tetraalkylthiuram disulfide with alkynes/alkenes has been developed using Selectfluor at room temperature. The formed 1,3-dithiol-2-ylium/1,3-dithiolan-2-ylium salts can be easily transformed into the corresponding 1,3-dithiol-2-ylidenes/1,3-ditholan-2-ylidenes by one-pot subsequent condensation with malononitrile. The present protocol features the use of easily accessible starting materials, mild reaction conditions, good tolerance with diverse functional groups, easy scale-up, and a wide substrate scope, affording the desired products in good yields. Importantly, this method is suitable for the late-stage modification of bioactive molecules. Furthermore, 1,3-dithiol-2-ylium salt can also be easily converted into various 1,3-dithiole derivatives by condensation, reduction, or hydrolysis. Mechanism studies show that this transformation involves radical annulation. Of note, this method presented a novel example using tetraalkylthiuram disulfide as a sulfur synthon in annulation, which greatly enriches the application of tetraalkylthiuram disulfides in organic synthesis. Biological evaluation indicates that these prepared compounds are promising candidates in terms of their antitumor activity.

Synthesis, Spectroscopic and Antibacterial Studies of Some N-Phenylpyridinium Chloride Derivatives

Aim and Background: This study represents a dedicated effort to advance organic chemistry and contribute to the development of innovative therapeutic agents through the synthesis, spectroscopic characterization, and antibacterial activities of N-phenylpyridinium chloride derivatives. Heterocyclic compounds, integral to vital natural products, have spurred interest for their potential incorporation into the design of biologically active molecules. Methodology: The rigorous methodology employed stringent laboratory conditions, utilizing high-grade reagents, and implementing solvent purification through distillation and crystallization. The synthesis involved refluxing pyridine and 1-chloro-2, 4-dinitrobenzene in ethanol, resulting in N-2, 4-dinitrophenylpyridinium chloride. Derivatization with aniline produced 5-anilino N-phenyl-2, 4-pentadienylideniminium chloride, undergoing cyclization and meticulous purification. Result: Antibacterial evaluations demonstrated significant efficacy, with 1-(2-chlorophenyl) pyridinium chloride exhibiting pronounced sensitivity against E. coli and S. aureus. Paper chromatography revealed strong affinities for the stationary phase, indicative of their inherently polar nature. Fourier transform infrared (FTIR) spectroscopy provided insights into diverse functional groups. Conclusion: The Meticulous synthesis of N-phenylpyridinium chloride derivatives has yielded compounds with notable antibacterial properties, showcasing their potential applications in both medical and materials science domains. This study concludes by emphasizing the critical importance of continued exploration in this promising research trajectory, highlighting the essential intersection of organic chemistry with advancements in therapeutic innovation.

Integrated evaluation of the impact of water diversion on water quality index and phytoplankton assemblages of eutrophic lake: A case study of Yilong Lake

Water diversion has been widely utilized to enhance lake water quality and mitigate cyanobacterial blooms. However, previous studies have mainly focused on investigating the effects of water diversion on water quality or aquatic ecological health. Consequently, there is limited research investigating the combined impact of water diversion on the water quality and the ecological health of eutrophic lakes, and whether the WQI and phytoplankton assemblages demonstrate similar patterns following water diversion. In this study, the effects of water diversion on the ecosystem health of eutrophic lakes were comprehensively evaluated based on the WQI indices and phytoplankton assemblages during the NWDP-21 and WDP-22. The results showed that the annual mean of WQI increased from 52.02 to 54.36 after water diversion, which improved the water quality of the lake, especially NH3–N and TN decreased by 58.6% and 15.2%, respectively. The phytoplankton assemblages changed significantly before and after water diversion, and we observed that the total biomass of phytoplankton decreased by 12.3% and phytoplankton diversity indices (Shannon-Wiener diversity, Pielou evenness, and Simpson index) increased by 8.6%–8.9% after water diversion, with an improvement in the connectivity and stability of the phytoplankton. Notably, enhanced adaptations of rare sub-communities for resource use in water diversion environments, and water diversion inhibited the dispersal ability of dominant functional groups, and the effects of hydrological disturbances on the structure of phytoplankton assemblage favored the ecological health of eutrophic lakes. VPA analysis further reveals that water diversion alters the drivers of phytoplankton functional group biomass and phytoplankton diversity. The results of the PLS-PM analysis clarify that water diversion indirectly impacts the total phytoplankton biomass and phytoplankton diversity primarily by modifying light availability. Significant correlations are observed between the dominant functional groups biomass and diversity indices of WQI. The trends in changes observed in water quality indices and phytoplankton following water diversion align with the evaluation of water ecological health. This study provides valuable guidance for the ecological management of the diversion project in Yilong Lake and serves as a reference for similar projects in other lakes.

Synthesis of Quinine‐Inspired Antimalarials by Ni‐Catalysed Cross Electrophile Coupling

AbstractWe describe the efficient synthesis of novel dehydroxyquinines by arylation of quincorine bromide using Ni‐catalysed cross electrophile coupling. The method demonstrates robust compatibility with (hetero)aryl bromides bearing diverse functional groups. Oxidation at C‐9 of the dehydroxyquinines expediently provided quinine‐inspired pseudo‐natural products (‘quinalogs’). Investigation of the compound collection against Plasmodium falciparum revealed a new insight into the structure activity relationship of quinine. Analogs bearing specifically functionalised pyridines, in place of the 6‐methoxyquinoline ring of quinine, retained activity at the same order of magnitude, albeit not exceeding the activity of the natural product. This synthetic strategy conveniently enables iteration of the aromatic component of quinine for the first time, and holds promise for the development of effective new antimalarials.

Realizing Stable Perovskite Solar Cells with Efficiency Exceeding 25.6% Through Crystallization Kinetics and Spatial Orientation Regulation.

Organic-inorganic hybrid perovskites have emerged as highly promising candidates for photovoltaic applications, owing to the exceptional optoelectronic properties and low cost. Nonetheless, the performance and stability of solar cells suffer from the defect states of perovskite films aroused by non-optically active phases and non-centralized crystal orientation. Herein, a versatile organic molecule, Hydantoin, to modulate the crystallization of perovskite, is developed. Benefiting from the diverse functional groups, more spatially oriented perovskite films with high crystallinity are formed. This enhancement is accompanied by a conspicuous reduction in defect density, yielding efficiency of 25.66% (certified 25.15%), with superb environmental stability. Notably, under the standard measurement conditions (ISOS-L-1I), the maximum power point (MPP) output maintains 96.8% of the initial efficiency for 1600 h and exhibits excellent ion migration suppression. The synergistic regulation of crystallization and spatial orientation offers novel avenues for propelling perovskite solar cell (PSC) development.

Chemoselective Transfer Hydrogenation of Nitroarenes with Ammonia Borane Catalyzed by Copper N‐heterocyclic Carbene Complexes

Comprehensive SummaryHerein, we present a method for the homogeneous hydrogenation of nitroarenes to produce anilines using low catalyst loading (1 mo%) of copper N‐heterocyclic carbene complexes as the catalyst and ammonia borane as the source of hydrogen. A wide range of nitroarenes, featuring diverse functional groups, were selectively transformed into their corresponding primary aromatic amines with high yields. This process can be readily scaled up and exhibits compatibility with various sensitive functional groups, including halogen, trifluoromethyl, aminomethyl, alkenyl, cyano, ester, amide, and hydroxyl. Notably, this catalytic methodology finds application in the synthesis of essential drug compounds. Mechanistic investigations suggest that the in‐situ‐generated Cu‐H species may serve as active intermediates, with reduction pathways involving species such as azobenzene, 1,2‐diphenylhydrazine, nitrosobenzene, and N‐phenylhydroxylamine.

Functional group diversity of soil macroarthropods in tropical rainforest areas of Bukit Pinang-Pinang Padang, Indonesia: implications for ecosystem balance

Functional group diversity of soil macroarthropods in tropical rainforest areas of Bukit Pinang-Pinang Padang, Indonesia: implications for ecosystem balance

Boosting the Reactivity of Bis-Lactones to Enable Step-Growth Polymerization at Room Temperature.

The development of new sustainable polymeric materials endowed with improved performances but minimal environmental impact is a major concern, with polyesters as primary targets. Lactones are key monomers thanks to ring-opening polymerization, but their use in step-growth polymerization has remained scarce and challenging. Herein, we report a powerful bis(γ-lactone) (γSL) that was efficiently prepared on a gram scale from malonic acid by Pd-catalyzed cycloisomerization. The γ-exomethylene moieties and the spiro structure greatly enhance its reactivity toward ring-opening and enable step-growth polymerization under mild conditions. Using diols, dithiols, or diamines as comonomers, a variety of regioregular (AB)n copolymers with diverse linkages and functional groups (from oxo-ester to β-thioether lactone and β-hydroxy-lactame) have been readily prepared. Reaction modeling and monitoring revealed the occurrence of an original trans-lactonization process following the first ring-opening of γSL. This peculiar reactivity opens the way to regioregular (ABAC)n terpolymers, as illustrated by the successive step-growth polymerization of γSL with a diol and a diamine.

Synthesis, structural elucidation and characterization of a new organic single crystal Guanidinium adipate monohydrate (GuAM) for nonlinear optical applications

A slow evaporation solution growth process was employed to grow a new organic single crystal Guanidinium adipate monohydrate (GuAM) at room temperature. The structure refinement and cell specifications were elucidated using the X-ray diffraction method. Single crystal XRD study revealed that the grown crystal crystallized in the monoclinic system with unit cell dimensions a = 4.948 (9) Å; b = 16.770 (2) Å; c = 13.554 (2) Å; α and γ = 90.00⁰; β = 95.302⁰ (3), V = 1120.1(3) Å3 and Z = 4. The structure of the crystal was solved by direct method and refined by full matrix least-square method using SHELXL-2018/3 program. The crystalline nature of the sample was evaluated by powder X-ray diffraction (PXRD) study. Fourier transform infrared (FTIR) spectral study was employed to recognize the diverse functional groups present in the synthesized crystal. Optical attributes such as absorbance and emission nature of the GuAM were explored using UV–visible-NIR absorbance study and photoluminescence study respectively. The laser damage threshold value of the formed crystal has been determined by employing an Nd-YAG laser with a wavelength of 1064 nm. The mechanical nature of the GuAM was examined utilizing Vicker's microhardness test and other related parameters were also calculated. TGA-DTA analysis was utilized to estimate the title crystal's thermal stability. The Z-scan technique has been employed to gain insight into the third order nonlinear (NLO) parameters of the GuAM. These findings imply that guanidinium adipate monohydrate (GuAM), a grown single crystal, may be a viable choice for NLO applications.

Abstract 4421: Intracellular cytomatrix actin and the Warburg effect

Abstract Introduction: The cytoplasm of living cells is dynamic and the motion arising from fluctuating forces in cells is an active process, rather than being thermally induced. Motor proteins could be the primary causative force of intracellular movement. However, which motor protein is involved in the intracellular dynamics, what process requires fluctuational intracellular activity, and where the energy source comes from is unknown. To address the impact of intracellular motion in cellular processes, we chemically separated the viscous fluid (cytosol) and elastic solid (cytomatrix) phases of cytoplasm. The multiomic analysis was used to dissect the compositional differences between the liquid and solid phases. LC-MS/MS-based proteome analysis was used to identify the composition of the HCT-15 colon cancer cell cytomatrix. The mRNA translation was measured by Ribosome footprinting. Results: Since the kinesis of the solid phase can trigger liquid phase flux, the composition of the cytomatrix was the primary focus of the study of cytoplasmic motion. The systemic analysis of the cytomatrix constituency allowed the identification of a diverse functional group of proteomes that included cytoskeletal and structural elements of organoids, metabolic enzymes, and normal- and proto-oncogenic signaling pathways. The two-phase system elucidated how diverse chemical reactions can occur simultaneously within the cell cytoplasm. Namely, the immobilization of catalytic complexes on the solid cytomatrix physically segregates biochemical reactants, thereby overcoming spatial impediments and allowing diverse metabolic reactions to coincide. Actomyosin and other actin-binding proteins of cytomatrix were the most abundant and diverse proteome, indicating that the primary machinery driving cytomatrix mobility consists of actomyosin, actin-binding, and actin-regulating proteins of cytomatrix. The cytomatrix dynamics trigger the cytosolic motion that carries substrates to immobilized catalytic complexes of the cytomatrix, thereby increasing product output, which appears to be a more intense process in cancer cells due to genetic and epigenetic aberrations. Under normal physiological conditions, mitochondrial respiration can deliver the energy requirements of cytomatrix micromechanics, but in cancer cells, additional energy of ATP is supplied by the aerobic glycolysis known as the Warburg effect to provide the ATP surplus for actomyosin mechanics. Conclusion: The intracellular motion is supported through non-muscle actomyosin action of the solid phase (cytomatrix), permitting increased glycolytic pathway activity in tumor cells. This novel concept of cancer links the Warburg effect with the bioenergetics of cytomatrix micromechanics and the dynamics of metabolic processes in tumors. Thus, two of the mysteries in cancer cell biology, how chemical reactions occur in the cytoplasm and energy is generated by tumor cells, have now been linked. Citation Format: Tattym E. Shaiken. Intracellular cytomatrix actin and the Warburg effect [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 4421.

Multi-functional ion-pairing additive for efficient quasi-2D perovskite light-emitting diodes and solar cells

Due to their unique quantum confinement, dielectric coupling, and tunable high-efficiency electroluminescence, quasi-two-dimensional (quasi-2D) perovskite light-emitting diodes (PeLEDs) have attracted considerable attention. However, imperfections in perovskite thin films introduced during the solution-based fabrication process lead to significant non-radiative recombination, hindering device performance. Addressing this challenge is crucial for realizing high-performance quasi-2D PeLEDs. In this study, we introduce an ion-pairing-type additive, 6-maleimidohexanehydrazide trifluoroacetate (EMCH-TFA), designed to cooperatively passivate defects in quasi-2D perovskites. The diverse functional groups (–COOH, –NH2, -CF3) on EMCH-TFA could provide disparate modification to perovskite, among which the CO group tends to coordinate with the uncoordinated Pb2+ ions, thereby passivating the defects in the perovskite crystal. Additionally, the –NH2 and -CF3 groups establish hydrogen bonds with Br- ions and BA+ spacer cations, respectively. This multifaceted approach suppresses the formation of the small n phase and induces alterations in the crystalline state by interacting with numerous sites in perovskites, including A’, B, and X sites. Consequently, the quasi-2D PeLED based on BA2Csn-1PbnBr3n+1 exhibits enhanced brightness, achieving a current efficiency of 66.7 cd/A and an impressive external quantum efficiency of 19.77 %.

Model-Assisted Optimization of Cobalt Biosorption on Macroalgae Padina pavonica for Wastewater Treatment

The release of heavy metals into the environment as a result of industrial and agricultural activities represents one of the century’s most significant issues. Cobalt is a hazardous metal that is employed in a variety of industries. In this study, response surface methodology (RSM) combined with Box–Behnken design (BBD) was utilized to optimize the Co(II) ion removal from synthetic wastewater by the brown macroalga Padina pavonica. The influence of three factors, namely algal inoculum size, pH, and initial metal concentration, was assessed in optimization studies. RSM proposed a second-order quadratic model with a p-value of <0.0001 and R2 of 0.984 for P. pavonica. According to the data related to RSM optimization, the maximum percentage of Co(II) removal of 84.3% was attained under the conditions of algal inoculum size of 5.98 g/L, pH of 6.73, and initial Co(II) concentration of 21.63 mg/L. The experimental data from the biosorption process were fitted well with the Langmuir, Freundlich, and Temkin isotherm models. The maximal Co(II) adsorption capacity was estimated using the Langmuir model to be 17.98 mg/g. Furthermore, the pseudo-second-order kinetic model was shown to have the best fit for Co biosorption by P. pavonica, showing that the mechanism of Co(II) biosorption was chemisorption controlled by surface biosorption and intra-particle diffusion. Thermodynamic parameters were also investigated to evaluate the Gibbs free energy for the Co(II) ion, which was positive, showing that the biosorption process is nonspontaneous and exothermic, and the cobalt biosorption rate decreases with increasing temperature. Algal biomass was characterized by Fourier transform infrared spectroscopy, scanning electron microscopy, and energy dispersive spectroscopy. These analyses revealed the biosorbent’s diverse functional groups and porous, rough appearance. Therefore, P. pavonica can be used to implement sustainable, eco-friendly, and acceptable solutions to water pollution problems.

Cysteine-Specific Multifaceted Bioconjugation of Peptides and Proteins Using 5-Substituted 1,2,3-Triazines.

Peptide and protein postmodification have gained significant attention due to their extensive impact on biomolecule engineering and drug discovery, of which cysteine-specific modification strategies are prominent due to their inherent nucleophilicity and low abundance. Herein, the study introduces a novel approach utilizing multifunctional 5-substituted 1,2,3-triazine derivatives to achieve multifaceted bioconjugation targeting cysteine-containing peptides and proteins. On the one hand, this represents an inaugural instance of employing 1,2,3-triazine in biomolecular-specific modification within a physiological solution. On the other hand, as a powerful combination of precision modification and biorthogonality, this strategy allows for the one-pot dual-orthogonal functionalization of biomolecules utilizing the aldehyde group generated simultaneously. 1,2,3-Triazine derivatives with diverse functional groups allow conjugation to peptides or proteins, while bi-triazines enable peptide cyclization and dimerization. The examination of the stability of bi-triazines revealed their potential for reversible peptide modification. This work establishes a comprehensive platform for identifying cysteine-selective modifications, providing new avenues for peptide-based drug development, protein bioconjugation, and chemical biology research.

Investigations on the enhanced anti-microbial activity of one step synthesized ZnO, WO3, and rGO nano particles and fabrication of rGO nano electrode for EMG biomedical application

Abstract The proposed study aims to synthesize ZnO, WO3, and rGO nano particles (NPs) using simple and effective chemical reduction technique and to investigate its biomedical applications. According to the XRD results, synthesized NPs had hexagonal, monoclinic, and cubic crystal forms. The FESEM micro image shows sheet-like structure for rGO NPs, an algal crystal structure for ZnO, and a bulk cluster formation for WO3 NPs. The value of band gap was found to be 5.75, 5.37 and 3.01 eV for ZnO, WO3, and rGO NPs respectively. The presence of diverse functional groups in the produced NPs was verified using Fourier-transform infrared spectroscopy. Investigations against different microorganisms indicated an augmentation in the antibacterial activity for ZnO and WO3 NPs. Electrodes coated with rGO NP were made and discovered to be effective in collecting human biomedical data more effectively. The performance of rGO NP coated electrodes was compared using a development board for electromyography analysis along with an android application for monitoring purposes. The quality of the signal, the ratio between the signal and the background noise, as well as the level of impedance between the electrode and the skin was observed to be better than conventional electrodes.

Diamond surface functionalization via visible light–driven C–H activation for nanoscale quantum sensing

Nitrogen-vacancy (NV) centers in diamond are a promising platform for nanoscale NMR sensing. Despite significant progress toward using NV centers to detect and localize nuclear spins down to the single spin level, NV-based spectroscopy of individual, intact, arbitrary target molecules remains elusive. Such sensing requires that target molecules are immobilized within nanometers of NV centers with long spin coherence. The inert nature of diamond typically requires harsh functionalization techniques such as thermal annealing or plasma processing, limiting the scope of functional groups that can be attached to the surface. Solution-phase chemical methods can be readily generalized to install diverse functional groups, but they have not been widely explored for single-crystal diamond surfaces. Moreover, realizing shallow NV centers with long spin coherence times requires highly ordered single-crystal surfaces, and solution-phase functionalization has not yet been shown with such demanding conditions. In this work, we report a versatile strategy to directly functionalize C-H bonds on single-crystal diamond surfaces under ambient conditions using visible light, forming C-F, C-Cl, C-S, and C-N bonds at the surface. This method is compatible with NV centers within 10 nm of the surface with spin coherence times comparable to the state of the art. As a proof-of-principle demonstration, we use shallow ensembles of NV centers to detect nuclear spins from surface-bound functional groups. Our approach to surface functionalization opens the door to deploying NV centers as a tool for chemical sensing and single-molecule spectroscopy.

Polyamidoamine dendrimers modified MXene and its high-performance adsorption behavior for Cr(VI)

Heavy metal pollution of water is a worldwide problem. The enticing characteristics exhibited by transition metal carbides (MXene) render it a good choiceas an adsorbent for removal of water pollutants. However, the limited functional group diversity and number, as well as the inadequate stability of MXene, impose limitations on its suitability for the adsorption of specific target metal ions (e.g., Hexavalent Cr(VI)). Herein, polyamidoamine (PAMAM) dendrimers, namely hyperbranched surfactant polymers, are employed to modify MXene, enhancing its surface functional group diversity and number. The presence of abundant –NH2 groups on the surface of PAMAM-modified MXene greatly enhances the adsorption capacity for Cr(VI). The pseudo-second order kinetic model and Langmuir isotherm model are suitable for describing the adsorption process. According to the Langmuir isotherm model, the maximum adsorption capacity (qm) can reach approximately 318 mg·g−1. Additionally, this adsorbent also has an excellent adsorption selectability for Cr(VI) from coexistent cations solution. Through the mechanisms of electrostatic attraction, reduction, covalent bonds, and chelation interaction, the high-performance adsorption for Cr(VI) can be achieved. Notably, the presence of PAMAM polymer as a protector ensures good stability of the composite adsorbent throughout adsorption/desorption cycle. This work provides deep insights into the advancement of highly efficient MXene-based adsorbents for water purification applications.

Chemoenzymatic Installation of Site-Specific Chemical Groups on DNA Enhances the Catalytic Activity.

Functional DNAs are valuable molecular tools in chemical biology and analytical chemistry but suffer from low activities due to their limited chemical functionalities. Here, we present a chemoenzymatic method for site-specific installation of diverse functional groups on DNA, and showcase the application of this method to enhance the catalytic activity of a DNA catalyst. Through chemoenzymatic introduction of distinct chemical groups, such as hydroxyl, carboxyl, and benzyl, at specific positions, we achieve significant enhancements in the catalytic activity of the RNA-cleaving deoxyribozyme 10-23. A single carboxyl modification results in a 100-fold increase, while dual modifications (carboxyl and benzyl) yield an approximately 700-fold increase in activity when an RNA cleavage reaction is catalyzed on a DNA-RNA chimeric substrate. The resulting dually modified DNA catalyst, CaBn, exhibits a kobs of 3.76 min-1 in the presence of 1 mM Mg2+ and can be employed for fluorescent imaging of intracellular magnesium ions. Molecular dynamics simulations reveal the superior capability of CaBn to recruit magnesium ions to metal-ion-binding site 2 and adopt a catalytically competent conformation. Our work provides a broadly accessible strategy for DNA functionalization with diverse chemical modifications, and CaBn offers a highly active DNA catalyst with immense potential in chemistry and biotechnology.