Acetylation Research Articles

Topological structure, rheological characteristics and biological activities of exopolysaccharides produced by Saccharomyces cerevisiae ADT

Saccharomyces cerevisiae ADT is an edible fungus, with limited research on its exopolysaccharides (EPS). Three types of exopolysaccharides (EPS60, EPS80, and EPS100) were obtained through multiple purification steps using varying concentrations of ethanol in this study. The topological structure, rheological properties, and biological characteristics of EPS were investigated. High performance liquid chromatography (HPLC), Fourier transform infrared spectroscopy (FTIR), and nuclear magnetic resonance (NMR) analyses indicated that the three EPS are primarily made up of mannose with a small amount of glucose. Acetyl groups were also found, along with the presence of α-type pyranose and β-type pyranose. The Congo Red test and X-ray diffraction results reflected the absence of a triple helix structure and crystal properties. Atomic force microscopy (AFM) revealed the self-assembly of three exopolysaccharides into various topological structures under different concentration gradients, and a clear network structure of entangled chains was observed. EPS60, EPS80 and EPS100 displayed pseudoplasticity, weak gel behavior and thermal stability. Significantly, EPS exhibited antioxidant activity in a dose-dependent manner and showed no acute cytotoxicity to RAW264.7 and HEK293T cells. Therefore, EPS in this study is anticipated to be utilized in natural antioxidants, medications, and functional materials.

Dynamic proton migration in dual linkage-engineered D-π-A system for photosynthesis H2O2 generation

Accelerated charge migration and proton transfer to the reaction site are critical factors for improving photocatalytic efficiency. However, realizing both simultaneously is challenging because of the sluggish water (proton source) oxidation kinetics and interdependent redox reactions. Herein, we design an imide and hydrogen bond to connect carbon nitride ports of the D-π-A system with the dual-engineered linkages. The system uses an acetylene functional group and an imidazole ring as spatially separated water oxidation and oxygen reduction reaction (ORR) catalytic centers for photogenerated charge separation, respectively. The imine bond is a bridge grafted to the oxidation site to act as a hydrogen proton trap, and the hydrogen bond formed between reduction site and carbon nitride is used as the channel for instantaneous proton delivery to the reduction center. In situ characterization confirms that the linking sites protonation optimizes the pathway of ORR to H2O2 and facilitates the *OOH intermediates generated. It is concluded that proton transport plays a critical role in optimizing photocatalytic H2O2 production. Our work provides a strategy to improve dynamic proton transfer mechanisms.

Influence of Hydroxycoumarin Substituents on the Photophysical Properties of Chiroptical Tb(III) and Eu(III) Complexes.

In this article, the synthesis, density functional theory (DFT) structural characterization, and spectroscopic investigation of chiral and heteroleptic Tb(III) and Eu(III) complexes are presented. These molecules are characterized by two different ligands: the enantiopure N,N'-bis(2-pyridylmethyl)-trans-1,2-diaminocyclohexane-N,N'-diacetic acid (H2bpcd) and a hydroxycoumarin-based ligand bearing different substituents in C(3) position (i.e., acetyl group in Coum, ethyl ester in CoumA, secondary and tertiary amides in CoumB and CoumC, respectively). The coumarin ligands exhibited different luminescence sensitization efficiency toward Tb(III) and Eu(III) ions in the related complexes of chemical formula [Ln(bpcd)(Coum)], [Ln(bpcd)(CoumA)], [Ln(bpcd)(CoumB)], [Ln(bpcd)(CoumC)]. Through theoretical calculations of intramolecular energy transfer (IET) processes (ligand-to-metal) in Eu(III) and Tb(III) complexes, along with quantum yield calculations, we provide a reasonable explanation for the observed differences in their luminescence properties. The nature of the coumarin ligand also affects the chiroptical properties of the Tb(III) complexes [i.e., circularly polarized luminescence (CPL) and electronic circular dichroism (ECD)].

Designing Phenolphthalein-Based Adsorptive Membranes for the High-Affinity, High-Capacity Capture of Contaminants from Water.

The selective removal of solutes is crucial for ensuring a sustainable water supply, recovering resources, and cost-effective biomanufacturing. Adsorptive membranes are promising in this regard due to their rapid mass transfer and low energy demands. However, state-of-the-art adsorptive membranes offer limited pore sizes and surface chemistries. This study reports the development of adsorptive membranes from reactive phenolphthalein-based (PPH-based) polymers. These polymers, which are molecularly engineered to possess a high density of reactive pendant groups, are transformed into porous membranes through a surface-segregation vapor-induced phase separation (SVIPS) method. Examining the thermodynamic characteristics of the polymer-solvent-nonsolvent system informs the SVIPS manufacturing process and facilitates the formation of diverse membrane morphologies with hydraulic permeabilities ranging from 3400 to 13,500 L m-2 h-1 bar-1. Copper ion binding experiments demonstrate a saturation capacity of 0.9 mmol Cu2+ g-1, indicating high accessibility of the pendant groups for postsynthetic modification. Functionalization with alkyne groups enables one-step click reactions, such as the thiol-yne and Cu(I)-catalyzed azide-alkyne cycloaddition, expanding the membrane functionality. The incorporation of cucurbit[7]uril-azide macrocycles demonstrates the affinity-mediated capture of methyl viologen from solution. The combination of PPH-based polymers and the SVIPS method provides a versatile adsorptive membrane platform with a dense presentation of reactive sites, facilitating customization through diverse and high-yielding reactions.

Robust Fluorescent Nanoprobe for Rapid Evaluation of the Selenium Supplementation Effect and Imaging.

At present, an increasing number of people pay more attention to selenium-enriched food, but the quality of the selenium-enriched food varies. Therefore, there is an urgent need to develop a new tool to assess the effects of selenium supplementation in foods by rapidly detecting the levels of the metabolite selenium selenocysteine (Sec). In this work, a fluorescent nanoprobe CS-Sec was designed, synthesized, and characterized for Sec detection and imaging in living biosystems, which exhibited the advantages of good biocompatibility, excellent water solubility, high sensitivity, high selectivity, and rapid response (2.5 min) for Sec detection and imaging in vitro and in vivo and evaluation of selenium supplementation in selenium-rich foods. Specifically, CS-Sec was constructed by grafting alkyne groups on organic small-molecule fluorescent probes with azide groups on azido chitosan by click chemistry. A 2,4-dinitrophenyl ether (DNB) with a strong intramolecular charge transfer (ICT) effect was selected as a response group and fluorescence-quenching group, which had excellent chemical specificity toward Sec. In addition, CS-Sec has high selectivity and sensitivity toward Sec over other analytes, and an excellent limit of detection (LOD) is as low as 15 nM. Impressively, CS-Sec has been successfully used to detect and image the concentration of Sec in living HepG2 cells and mouse models with exciting results, indicating that the newly constructed CS-Sec can provide a robust molecule tool for the rapid evaluation of the selenium supplementation effect and imaging in the future.

In silico identification of Histone Deacetylase inhibitors using Streamlined Masked Transformer-based Pretrained features

Histone Deacetylases (HDACs) are enzymes that regulate gene expression by removing acetyl groups from histones. They are involved in various diseases, including neurodegenerative, cardiovascular, inflammatory, and metabolic disorders, as well as fibrosis in the liver, lungs, and kidneys. Successfully identifying potent HDAC inhibitors may offer a promising approach to treating these diseases. In addition to experimental techniques, researchers have introduced several in silico methods for identifying HDAC inhibitors. However, these existing computer-aided methods have shortcomings in their modeling stages, which limit their applications. In our study, we present a Streamlined Masked Transformer-based Pretrained (SMTP) encoder, which can be used to generate features for downstream tasks. The training process of the SMTP encoder was directed by masked attention-based learning, enhancing the model's generalizability in encoding molecules. The SMTP features were used to develop 11 classification models identifying 11 HDAC isoforms. We trained SMTP, a lightweight encoder, with only 1.9 million molecules, a smaller number than other known molecular encoders, yet its discriminant ability remains competitive. The results revealed that machine learning models developed using the SMTP feature set outperformed those developed using other feature sets in 8 out of 11 classification tasks. Additionally, chemical diversity analysis confirmed the encoder's effectiveness in distinguishing between two classes of molecules.

Advanced BiVO4-deoxygenated lignocellulosic photocatalyst for effective degradation of organic and heavy metal pollutants in aqueous system

Bismuth vanadate (BiVO4) is a common photocatalyst for water remediation, yet its powder form renders difficult to disperse, recycle, and regenerate, limiting photodegradation efficiency. In this study, a lignocellulosic-templated BiVO4 photocatalyst was fabricated from BiVO4 precursor and lignocellulose using a simple vacuum impregnation (w/o heat treatment on wood template). Results showed that the modified template retained original hierarchical structure with an increased specific surface area and reduced hemicellulose content, leading to a promising template for uniform distribution of BiVO4. Moreover, compared to untreated, heat treatment cleaved acetyl groups in the hemicellulose chain, broke down fatty ether bonds, and oxidized lignin side chains, resulting in no disruption to the catalysis of BiVO4. The BiVO4-pyrolyzed lignocellulosic photocatalyst achieved remarkable degradation efficiencies of 90.03 % (approximately 7-fold increase compared to untreated) for RhB and complete degradation of Cr (VI) within 60 min. Furthermore, the efficiency remained >80 % after seven cycles. The mechanism was hypothesized that BiVO4 and template play distinct roles, as deoxygenated lignocellulosic template only acts as a carrier for BiVO4 growth, and BiVO4 serves as the photocatalyst. However, untreated template can react with BiVO4 and impair photocatalytic efficiency. The BiVO4-pyrolyzed lignocellulosic photocatalyst holds great promise for the remediation of aqueous contaminants.

Progressive degradation of acetylated wood by the brown rot fungi Coniophora puteana and Rhodonia placenta

AbstractAcetylation is a wood modification method that reduces the hygroscopicity of wood and increases its resistance to degradation by wood decaying fungi. Even though acetylated wood can have very high decay resistance, the wood material can be degraded and sometimes deacetylated by fungi. This study investigated the degradation and deacetylation of acetylated wood by Coniophora puteana and Rhodonia placenta to better understand the relationship between degradation and deacetylation in two different brown rot fungi. Wood samples were exposed to the fungi in a stacked-sample decay test, followed by acetyl content measurements and FTIR spectroscopy to investigate chemical changes in the samples. The results showed that both fungi could degrade acetylated wood to high mass loss despite a strong reduction in moisture content, but only R. placenta was found to cause preferential deacetylation. The deacetylation was slight and only observed in the early stages of decay in highly acetylated wood. Otherwise, acetyl groups were lost from the samples at the rate of mass loss. FTIR spectroscopy confirmed the loss of acetyl groups and revealed some chemical differences between unacetylated and acetylated wood. The spectral data indicated the loss of acetyl groups from lignin, which suggests that the loss of acetyl groups is not only due to the degradation of acetylated carbohydrates. The degradation of acetylated wood required further investigation, but it is clear that extensive deacetylation is not a requirement for brown rot degradation.

Addition of a Perfluoroalkyl Acetyl Group to the C-Vertex of a Carborane Anion to Enhance Its Solubility in Fluorinated Ether Solvents

The modification of carborane anion monocarba-closo-dodecaborate (1) with perfluoroalkyl groups enhances its solubility in fluorinated ethers. This novel approach achieves a degree of solubility that is unattainable by using traditional lipophilic modifications or boro–vertex functionalizations of 1. A spectroscopic analysis in combination with DFT calculations confirmed that these new anions retain their weakly coordinating nature and exhibit moderate chemical stability.

Microcrystalline cellulose acetate incorporating cyanoacetyl moiety

AbstractThis work is part of our research to develop facile green methods for synthesizing bioactive molecules from biomass. The current study deals with the preparation and investigation of the newly synthesized cyanoacetyl-acetylated microcrystalline cellulose (CAA-MCC). The novelty of this derivative lies not only in its ability to act as a green dry-film biocide/UV blocker for eco-friendly waterborne paints but also in being biomass-derived via solar pulping of rice straw, which is a mild process that produces cellulosic pulp and non-toxic black liquor. Solar acid dissociation of the bleached pulp produces microcrystalline cellulose (MCC), which was utilized to synthesize its acetate derivative incorporating the cyanoacetyl moiety (CAA-MCC). The presence of acetyl and cyano acetyl groups in CAA-MCC was confirmed using elemental and spectral analyses, including FT-IR and NMR. Two sets of paint formulations were prepared, one with CAA-MCC and the other with the commercial dry-film biocide Rocima 363. Scanning electron microscope (SEM) and energy-dispersive X-ray (EDAX) analyses were performed for MCC, CAA-MCC, and the prepared dry films. CAA-MCC demonstrated moderate antibacterial activity, encouraging its evaluation as a dry-film biocide and UV blocker. CAA-MCC paint films showed resistance to microbial growth on their surfaces without inhibition zones. Moreover, films were exposed to ultraviolet (UV) radiation while monitoring their color change over time. The results revealed that films containing CAA-MCC were more resistant to deterioration than those containing Rocima 363. Viscosity, X-cut adhesion, hardness, and water resistance were also evaluated, and they all improved with the CAA-MCC addition. CAA-MCC could act as a new, cost-effective alternative to petrochemical-derived biocides and UV blockers that can improve paint performance. Graphical Abstract

New insight into linear substituents influencing electrooxidation treatment of sulfonamide antibiotics: Linking kinetics, pathways, toxicity, and active species with density functional theory

Linear substituents, despite their simpler structures compared to heterocyclic ones, exhibit distinct chemical behaviors. Using sulfacetamide (SAM) and sulfaguanidine (SGD) as model compounds, we assessed the impact of these substituents on degradation efficiency, active species identification, reaction pathways, and intermediate toxicity during electrooxidation in water. Through density functional theory, we elucidated the mechanisms, focusing on electronic structural changes and interactions with active species. Notably, the acetyl group in SAM (0.1016) acquired more electrons than the guanidyl group in SGD (0.0281), resulting in SAM having a higher free energy change (ΔG=15.06kcal/mol) compared to SGD (ΔG=9.59kcal/mol). This difference makes SAM less likely to undergo direct electron transfer and less reactive towards hydroxyl radical addition, leading to slower degradation rates. The applied potential notably increased SAM’s sensitivity to hydroxyl radicals. Both the highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) were contributed by the parent fragment, facilitating electrophilic reactions mainly on the aniline part. Seventeen intermediate products and three major transformation pathways were identified, emphasizing aniline group destruction before discharge. This research enhances understanding of the degradation and environmental fate of sulfonamides, providing valuable insights for optimizing pollutant degradation and discharge reduction.

Enhanced Rheological and Structural Properties of the Exopolysaccharide from Rhizobium leguminosarum VF39 Through NTG Mutagenesis.

Microbial exopolysaccharides (EPSs) are biopolymer materials with advantages such as biodegradability, biocompatibility, ease of mass production, and reproducibility. The EPS that was isolated from Rhizobium leguminosarum bv. viciae VF39 is an anionic polysaccharide with a backbone structure consisting of one galactose, five glucose molecules, and two glucuronic acids, along with 3-hydroxybutanoyl, acetyl, and pyruvyl functional groups. Through N-methyl-N'-nitro-N-nitrosoguanidine (NTG) mutagenesis, we isolated and purified a mutant EPS from VF39, VF39 #54, which demonstrated enhanced physicochemical and rheological properties compared to the wild-type VF39. The EPS structure of the VF39 #54 mutant strain showed a loss of glucuronic acid and 3-hydroxybutanoyl groups compared to the wild-type, as confirmed by FT-IR, NMR analysis, and uronic acid assays. The molecular weight of the VF39 #54 EPS was 250% higher than that of the wild-type. It also exhibited improved viscoelasticity and thermal stability. In the DSC and TGA analyses, VF39 #54 had a higher endothermic peak (172 °C) compared to the wild-type (142 °C), and its thermal decomposition point was 260 °C, surpassing the wild-type's value of 222 °C. Additionally, the VF39 #54 EPS maintained a similar viscosity to the wild-type in various pH, temperature, and metal salt conditions, while also exhibiting a higher overall viscosity. The cytotoxicity test using HEK-293 cells confirmed that the VF39 #54 EPS was non-toxic. Due to its high viscoelastic properties, the VF39 #54 EPS shows potential for use in products such as thickeners, texture enhancers, and stabilizers. Furthermore, its thermal stability and biocompatibility make it a promising candidate for applications in food, pharmaceuticals, and cosmetic formulations. Additionally, its ability to maintain viscosity under varying environmental conditions highlights its suitability for industrial processes that require consistent performance.

Role of the CTCF/p300 axis in osteochondrogenic-like differentiation of polyploid giant cancer cells with daughter cells

BackgroundPolyploid giant cancer cells (PGCCs) have properties of cancer stem cells (CSCs). PGCCs with daughter cells (PDCs) undergo epithelial–mesenchymal transition and show enhanced cellular plasticity. This study aimed to elucidate the mechanisms underlying the osteo/chondrogenic-like differentiation of PDCs, which may be exploited therapeutically by transdifferentiation into post-mitotic and functional cells.MethodsCobalt chloride was used to induce PGCC formation in MDA-MB-231 and HEY cells, and PDCs were cultured in osteo/chondrogenic differentiation media. Alcian blue staining was used to confirm osteo/chondrogenic differentiation, and the cell cycle was detected using flow cytometry. The expression of osteo/chondrogenic differentiation-related proteins was compared, and a co-immunoprecipitation assay was used to demonstrate the interactions between proteins. Bioinformatic analysis was used to explore the regulatory mechanism of osteo/chondrogenic differentiation, and a dual-luciferase reporter assay was performed to validate the interaction between transcriptional factors and target genes. Animal xenograft models were used to confirm the osteo/chondrogenic differentiation of PDCs.ResultsWhen cultured in osteo/chondrogenic medium, the stemness of PDCs decreased, and the expression of osteo/chondrogenic-related markers increased. This osteo/chondrogenic-like process was regulated by the transforming growth factor-β pathway in a time-dependent manner. A concurrent increase in the expression of histone acetyltransferase p300 and the transcription factor CCCTC-binding factor (CTCF) was observed. Co-immunoprecipitation assays revealed that p300 acetylated the osteo/chondrogenic marker RUNT-related transcription factor 2 (RUNX2). Analysis of chromatin immunoprecipitation sequencing datasets revealed that both CTCF and histone H3 lysine 27 acetylation (H3K27ac) were enriched in the promoter region of E1A-associated protein p300 (P300). The four predicted binding sites for CTCF and P300 were validated using dual-luciferase reporter assays. We examined the interaction between CTCF and H3K27ac and found that these two proteins had a combined effect on the transactivation of P300.ConclusionCTCF, in synergy with H3K27ac, amplified the expression of P300, facilitating acetyl group transfer to RUNX2. This acetylation stabilized RUNX2 and promoted osteo/chondrogenic differentiation, thereby reducing the incidence of PDC malignancies.

Unraveling the Band Structure and Orbital Character of a π-Conjugated 2D Graphdiyne-Based Organometallic Network.

Graphdiyne-based carbon systems generate intriguing layered sp-sp2 organometallic lattices, characterized by flexible acetylenic groups connecting planar carbon units through metal centers. At their thinnest limit, they can result in 2D organometallic networks exhibiting unique quantum properties and even confining the surface states of the substrate, which is of great importance for fundamental studies. In this work, the on-surface synthesis of a highly crystalline 2D organometallic network grown on Ag(111) is presented. The electronic structure of this mixed honeycomb-kagome arrangement - investigated by angle-resolved photoemission spectroscopy and scanning tunneling spectroscopy - reveals a strong electronic conjugation within the network, leading to the formation of two intense electronic band-manifolds. In comparison to theoretical density functional theory calculations, it is observed that these bands exhibit a well-defined orbital character that can be associated with distinct regions of the sp-sp2 monomers. Moreover, it is found that the halogen by-products resulting from the network formation locally affect the pore-confined states, causing a significant energy shift. This work contributes to the understanding of the growth and electronic structure of graphdiyne-like 2D networks, providing insights into the development of novel carbon materials beyond graphene with tailoredproperties.

Understanding the relationship between preferential interactions of peptides in water-acetonitrile mixtures with protein-solvent contact surface area.

The influence of polar, water-miscible organic solvents (POS) on protein structure, stability, and functional activity is a subject of significant interest and complexity. This study examines the effects of acetonitrile (ACN), a semipolar, aprotic solvent, on the solvation properties of blocked Ace-Gly-X-Gly-Nme tripeptides (where Ace and Nme stands for acetyl and N-methyl amide groups respectively and X is any amino acid) through extensive molecular dynamics simulations. Individual simulations were conducted for each peptide, encompassing five different ACN concentrations within the range of χACN = 0.1-0.9. The preferential solvation parameter (Γ) calculated using the Kirkwood-Buff integral method was used for the assessment of peptide interactions with water/ACN. Additionally, weighted Voronoi tessellation was applied to obtain a three-way data set containing four time-averaged contact surface area types between peptide atoms and water/ACN atoms. A mathematical technique known as N-way Partial Least Squares (NPLS) was utilized to anticipate the preferential interactions between peptides and water/ACN from the contact surface areas. Furthermore, the temperature dependency of peptide-solvent interactions was investigated using a subset of 10 amino acids representing a range of hydrophobicities. MD simulations were conducted at five temperatures, spanning from 283 to 343K, with subsequent analysis of data focusing on both preferential solvation and peptide-solvent contact surface areas. The results demonstrate the efficacy of utilizing contact surface areas between the peptide and solvent constituents for successfully predicting preferential interactions in water/ACN mixtures across various ACN concentrations and temperatures.

Synthesis of Clickable Isotactic Poly(vinyl ether)s through Organocatalytic Stereoselective Cationic Copolymerization.

By virtue of the high reliability of click chemistry, polymers with clickable groups provide a useful platform for the rapid synthesis of polymer materials with diverse functionalities and architectures. However, the polymerization of clickable vinyl monomers with a concurrent regulation on tacticity remains underdeveloped. Herein, we report the successful development of a stereoselective cationic copolymerization of C-C triple bond-containing vinyl ethers with simple alkyl vinyl ethers by employing confined Brønsted acid as catalyst, which allows for the synthesis of alkyne-functionalized vinyl ether copolymers with high isotacticity (up to 90% m), controlled molecular weight, and variable content of C-C triple bonds. Further transformation of the pendant clickable alkyne groups via thiol-yne click reactions and copper(I)-catalyzed alkyne-azide cycloaddition reaction enables a modular access to isotactic polymers with various functional groups.

Novel Ratiometric Surface-Enhanced Raman Scattering (SERS) Biosensor for Ultrasensitive Quantitative Monitoring of Human Carboxylesterase-1 in Hepatocellular Carcinoma Cells Using Ag-Au Nanoflowers as SERS Substrate.

In this study, we developed ratiometric surface-enhanced Raman scattering (SERS) biosensors using Ag-Au alloy nanoflowers as SERS substrates, molecules having amide bonds and alkyne groups (Tag A) as Raman reporters, and sodium thiocyanate as an internal standard molecule (Tag B) for the sensitive detection of human carboxylesterase-1 (hCE1) in HepG-2 cells. The correlation between HepG-2 cell damage and hCE1 activity levels was investigated. Both Tag A's alkyne group and Tag B's cyanide group produced characteristic SERS signals in the Raman-silent region (I2000cm-1 and I2115cm-1, respectively). The hydrolysis of the amide bond in Tag A via hCE1 and the shedding of the alkyne group led to a reduction in the SERS signal intensity observed at I2000cm-1. Conversely, the SERS signal intensity of Tag B at I2115cm-1 exhibited a consistent pattern. As the activity level of hCE1 and the ratiometric peak intensity (I2000cm-1/I2115cm-1) correlated negatively, hCE1 could be quantitatively detected within the range of 10-2 to 2 × 102 ng·mL-1, with a detection limit of 7.3 pg·mL-1. The ratiometric SERS probe strategy, in which a ratio response is employed, permits sensitive and reproducible SERS detection by facilitating intrinsic calibration to rectify signal fluctuations resulting from temporal and spatial variations in the detection conditions. Concurrently, the implementation of Raman-silent region reporter molecules mitigates the interference from endogenous biomolecules in SERS measurements and offers a novel approach for achieving highly sensitive and interference-free detection of intracellular hCE1.

Template Synthesis of the Iron(III) Complex with the Ligands Based on Acylpyrazolonepyridines

The reaction of new bidentate ligand, 1-(5-hydroxy-1-methyl-3-(pyridin-2-yl)-1Н-pyrazol-4-yl)ethan-1-one (L), with iron(III) chloride affords the mononuclear iron(III) complex FeL₂Cl₃, which is characterized by XRD (CIF file CCDC no. 2309481). The intramolecular hydrogen bond between the protonated pyridyl and acetyl groups in ligand L, which exists in the crystal as a zwitterion, provides the formation of rarely met iron complexes in which the β-diketonate fragment coordinates via the η1 mode. A similar coordination mode along with a possibility of a more favorable η2 coordination provides new possibilities for the design of heteropolynuclear compounds of various structures used in the fabrication of molecular devices of data storage and processing.

Elegant approach to intervention of homogalacturonan from the fruits of Ficus pumila L. in colitis: Unraveling the role of methyl esters and acetyl groups.

Oral administration of homogalacturonan (HG) has shown significant potential in anti-colitis activity, yet the therapeutic efficacy of naturally sourced HG still requires enhancement. Herein, HG from the fruits of Ficus pumila L. was modified by chemical methods and the intervention effect of modified HG with different degrees of methyl-esterification (DM) and acetylation (DA) on dextran sulfate sodium-induced colitis in mice was explored. Our results indicated that low-DM HG (DM3 and DM25) primarily mitigated colitis by reducing inflammation (TNF-α, IL-1β, IL-17, and IL-6), while high-DM HG (DM54 and DM94) primarily repaired the intestinal barrier. These effects may be attributed to the differential regulation of gut microbiota by HG with varying DM, such as Lachnospiraceae_NK4A136_group, Lactobacillus, Mucispirillum, Escherichia-Shigella, Bifidobacterium, and Bacteroides. Increased DA reduced the solubility of HG, showing limited anti-inflammatory response but unique advantages in intestinal barrier repair and microbiome regulation (Bifidobacterium, Candidatus_Saccharimonas, Lachnospiraceae_NK4A136_group, Mucispirillum, and Escherichia-Shigella). Furthermore, various structural parameters and substitution degrees showed no significant impact on HG's regulation of oxidative stress reactions. This study emphasized the importance of substituent effect in determining HG's functional role, providing a robust foundation for the design and development of functional polysaccharides for the prevention of intestinal inflammation and other related conditions.

Xanthan Gum Production and Its Modifications to Obtain Novel Applications: A Review

ABSTRACTBiopolymers are molecules widely used in many industries because they are biodegradable and have a natural origin. Therefore, they can be obtained from renewable resources and organisms such as animals, plants, or microorganisms. Among the best‐known biopolymers, xanthan gum is an anionic biopolymer composed of glucose, mannose, glucuronic acid, pyruvic acid, and acetyl groups. It can be obtained by fermentation with bacteria of the genus Xanthomonas, has good physicochemical properties, and it is biocompatible with human cells. However, it has disadvantages as it is very susceptible to microbial contamination. Therefore, various physical, chemical, or enzymatic modification methods have been developed to improve its physicochemical and biological properties. Modifications in the backbone of the xanthan gum chains have made it possible to create xanthan gum derivatives with new uses, such as drug delivery systems and improving absorption methods in the pharmaceutical industry to enhance the efficacy of several treatments or therapeutic processes, to promote cell proliferation for tissue engineering as biomedical applications when used in systems such as hydrogels or films. They are also used in food products, in cosmetics, to recover oil from water or ground, to treat wastewater, or granting soil with good conditions to promote plant and vegetables growth. Hence, it is important to know and develop new modification methods to improve and impart new properties to obtain novel applications of xanthan gum.