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Synthesis of polyurethane‐type poly[3]rotaxanes is achieved by polyaddition between a cyclodextrin (CD)‐based [3]rotaxane diol and various diisocyanate species, which provide a more defined structure compared to conventional polyrotaxane syntheses. In this study, hydroxyl groups on CDs of [3]rotaxane diol are initially acetylated, and deprotected after the polyaddition to introduce polyurethane backbone structure into polyrotaxane framework. Despite a relatively complicated chemical structure, [3]rotaxane diol monomer is successfully synthesized in a high yield (overall 67%) without any taxing purification process, which is beneficial for practical applications. The polymerization itself proceeds well under a standard polyaddition reaction condition to afford corresponding polyurethanes around 80% yield with Mn > 30 kDa. The poly[3]rotaxanes show different aggregation behavior or optical properties, whether or not acetyl groups are present, and are analyzed by XRD, SEM, and fluorescence measurements. [ABSTRACT FROM AUTHOR]

Effective fractionation of lignocelluosic biomass and subsequent valorization of all three major components under mild conditions were achieved. Pretreatment with acidified monophasic phenoxyethanol (EPH) efficiently removed 92.6 % lignin and 80 % xylan from poplar at 110 °C in 60 min, yielding high‐value EPH‐xyloside, EPH‐modified lignin (EPHL), and a solid residue nearly purely composed of carbohydrates. After removing the grafted acetyl groups using 1 % NaOH at 50 °C, the highest enzymatic digestibility reached 92.3 %. EPHL could be recovered in high yield and purity with an uncondensed structure, while xylose was converted to EPH‐xyloside, a potential precursor in biomedical industries. Additionally, the acidified monophasic EPH solvent could effectively fractionate biomass from species other than hardwood, achieving over 70 % delignification from recalcitrant pinewood under the same mild conditions, demonstrating the high potential of monophasic EPH pretreatment. [ABSTRACT FROM AUTHOR]

• Accurate and rapid identification of HDAC3i can significantly expedite the treatment of multiple diseases. • Stack-HDAC3i is an innovative and high-precision stacked framework for identifying HDAC3i using only the SMILES notation. • We employ both molecular and Mol2Vec embeddings to generate features covering multi-view information embedded in HDAC3i. • Our comparison results showed that Stack-HDAC3i is a highly accurate prediction model for identifying HDAC3 inhibitors. Epigenetics involves reversible modifications in gene expression without altering the genetic code itself. Among these modifications, histone deacetylases (HDACs) play a key role by removing acetyl groups from lysine residues on histones. Overexpression of HDACs is linked to the proliferation and survival of tumor cells. To combat this, HDAC inhibitors (HDACi) are commonly used in cancer treatments. However, pan-HDAC inhibition can lead to numerous side effects. Therefore, isoform-selective HDAC inhibitors, such as HDAC3i, could be advantageous for treating various medical conditions while minimizing off-target effects. To date, computational approaches that use only the SMILES notation without any experimental evidence have become increasingly popular and necessary for the initial discovery of novel potential therapeutic drugs. In this study, we develop an innovative and high-precision stacked-ensemble framework, called Stack-HDAC3i, which can directly identify HDAC3i using only the SMILES notation. Using an up-to-date benchmark dataset, we first employed both molecular descriptors and Mol2Vec embeddings to generate feature representations that cover multi-view information embedded in HDAC3i, such as structural and contextual information. Subsequently, these feature representations were used to train baseline models using nine popular ML algorithms. Finally, the probabilistic features derived from the selected baseline models were fused to construct the final stacked model. Both cross-validation and independent tests showed that Stack-HDAC3i is a high-accuracy prediction model with great generalization ability for identifying HDAC3i. Furthermore, in the independent test, Stack-HDAC3i achieved an accuracy of 0.926 and Matthew's correlation coefficient of 0.850, which are 0.44–6.11% and 0.83–11.90% higher than its constituent baseline models, respectively. [ABSTRACT FROM AUTHOR]

Despite the extraordinary anti-tubercular activity of isoniazid (INH), the druginduced hepatotoxicity and peripheral neuropathy pose a significant challenge to its wider clinical use. The primary cause of INH-induced hepatotoxicity is in vivo metabolism involving biotransformation on its terminal -NH2 group owing to its high nucleophilic nature. The human N-acetyltransferase-2 enzyme (NAT-2) exploits the reactivity of INH's terminal -NH2 functional group and inactivates it by transferring the acetyl group, which subsequently converts to toxic metabolites. This -NH2 group also tends to react with vital endogenous molecules such as pyridoxine, leading to their deficiency, a major cause of peripheral neuropathy. The elevation of liver functional markers is observed in 10%-20% of subjects on INH treatment. INH-induced risk of fatal hepatitis is about 0.05%-1%. The incidence of peripheral neuropathy is 2%-6.5%. In this review, we discuss the genesis and historical development of INH, and different reported mechanisms of action of INH. This is followed by a brief review of various clinical trials in chronological order, highlighting treatment-associated adverse events and their occurrence rates, including details such as geographical location, number of subjects, dosing concentration, and regimen used in these clinical studies. Further, we elaborated on various known metabolic transformations highlighting the involvement of the terminal -NH2 group of INH and corresponding host enzymes, the structure of different metabolites/conjugates, and their association with hepatotoxicity or neuritis. Post this deliberation, we propose a hydrolysable chemical derivatives-based approach as a way forward to restrict this metabolism. [ABSTRACT FROM AUTHOR]

Introduction: Histone deacetylases (HDACs) catalyze the removal of acetyl groups from lysine residues of histones and other proteins, generally leading to a closed chromosomal configuration and transcriptional repression. Different HDACs have distinct substrate specificities and functions in different biological processes. Accumulating evidence indicates that HDACs play a key role in the pathogenesis of multiple respiratory diseases. Areas covered: After an extensive search of the PubMed database, Web of Science and ClinicalTrials.gov, covering the period from 1992 to 2024, this review summarizes recent advances in understanding the role of HDACs in inflammatory respiratory diseases, including allergic rhinitis (AR), chronic rhinosinusitis (CRS), asthma and chronic obstructive pulmonary disease (COPD). We also examine recent progress on the efficacy and potential use of histone deacetylase inhibitors (HDACi) for the treatment of these diseases. Expert opinion: Available data indicate that HDACs play an important role in the development of common inflammatory respiratory diseases, and HDACi have shown promise as treatments for these diseases. However, the exact roles and underlying mechanisms of specific HDACs in disease pathogenesis require further study. Additional work is necessary to develop novel potent HDACi with high isoform selectivity. [ABSTRACT FROM AUTHOR]

In this paper for the first time, we report a simple one-step synthesis of 5-methyl-11,12-dihydro-5 H -5,11-epoxybenzo[7,8]oxocino[4,3- d ]pyrimidine derivatives by acid-catalyzed cyclization reaction of various 4-methyl-5-acetyl pyrimidine derivatives with salicylic aldehyde. It was shown that 2-substituted 4-methyl-5-acetylpyrimidines successfully react to form a cyclization product. At the same time, 4-methyl-5-acetylpyrimidines with a substituent in the 6th position do not enter into the cyclization reaction. This may be caused by the negative effect of substituents in the 6th position, which hinder the free rotation of the acetyl group and prevent the formation of a stable pre-reaction complex. The structures of the obtained 5-methyl-11,12-dihydro-5 H -5,11-epoxybenzo[7,8]oxocino[4,3- d ]pyrimidine derivatives were confirmed using1 H NMR and13 C NMR spectroscopy, mass spectrometry, and X-ray diffraction analysis. [ABSTRACT FROM AUTHOR]

A ligand-free approach for the Suzuki-Miyaura cross coupling reaction using Natural Deep Eutectic Solvents (NaDES) towards coumarin analogs is described. A model reaction between the synthetically prepared 3-(4-acetyloxy-phenyl)-6-bromo-4-methyl-coumarin (3b) and phenylboronic acid was performed in five different NaDES as well as in pure glycerol, using two inorganic bases and palladium catalysts. The reaction proceeded smoothly in Choline Chloride/Glycerol (ChCl/Gly) and Betaine/Glycerol (Bet/Gly) NaDES at 90 °C in 24 h, affording the desired product in high yields up to 95%. The combination of K2CO3, Pd(OAc)2 and ChCl/Gly NaDES provided optimum yields and high purity of the desired compounds, while the solvent was successfully recycled and reused up to two times. The developed methodology is applicable to boronic acids bearing various substituents. The formation of palladium nanoparticles in the reaction mixture was observed, and the size of the nanoparticles was associated with the reaction yield. In addition, in all the glycerol-based NaDES, an effective removal of the acetyl group of the acetyloxy–coumarin analogs was observed; thus, it is noteworthy that the Suzuki–Miyaura coupling and the deacetylation reaction were achieved in one pot. The ten novel coumarin derivatives synthesized were structurally characterized using 1D and 2D NMR spectroscopy and were tested for their cytotoxicity against the A431 squamous cancer cell line, presenting significant activity. [ABSTRACT FROM AUTHOR]

Simple Summary: Growth traits are important economic traits of broilers. We found the key metabolites that may be related to the body weight of Wumeng black-bone chicken by comparing their serum metabolomics between the high- and low-weight groups. Metabolites with high levels in serum such as riboflavin and 2-isopropylmalic acid may be beneficial to growth performance, and the enrichment of inflammation-related metabolites may be related to low body weight of chickens. Our results can provide a certain reference for the analysis of metabolic mechanism of body-weight formation of chickens. Growth performance is an important economic trait of broilers but the related serum metabolomics remains unclear. In this study, we utilized non-targeted metabolomics using ultra-high-performance liquid phase tandem mass spectrometry (UHPLC-MS/MS) to establish metabolite profiling in the serum of Chinese Wumeng black-bone chickens. The biomarker metabolites in serum associated with growth performance of chickens were identified by comparing the serum metabolome differences between chickens that significantly differed in their weights at 160 days of age when fed identical diets. A total of 766 metabolites were identified including 13 differential metabolite classes such as lipids and lipid-like molecules, organic acids and their derivatives, and organoheterocyclic compounds. The results of difference analysis using a partial least squares discriminant analysis (PLS-DA) model indicated that the low-body-weight group could be differentiated based on inflammatory markers including prostaglandin a2, kynurenic acid and fatty acid esters of hydroxy fatty acids (FAHFA), and inflammation-related metabolic pathways including tryptophan and arachidonic acid metabolism. In contrast, the sera of high-body-weight chickens were enriched for riboflavin and 2-isopropylmalic acid and for metabolic pathways including riboflavin metabolism, acetyl group transfer into mitochondria, and the tricarboxylic acid (TCA) cycle. These results provide new insights into the practical application of improving the growth performance of local chickens. [ABSTRACT FROM AUTHOR]

The study investigated the structures and properties of lyocell composite fibers with acetylated cellulose with varying relative acetylation substitution degrees (RDS). During pretreatment with NaOH/ethanol solution, some acetyl groups in the acetylated cellulose were hydrolyzed, leading to improve solubility in N-methylmorpholine-N-oxide (NMMO). The RDS was utilized to quantify the content of acetyl groups and acetylated cellulose with RDS between 0.516 ~ 0.571 that could dissolve in NMMO completely. The compatibility between cellulose and acetylated cellulose, with RDS values of 0.516, 0.543 and 0.571 respectively, was demonstrated through rheological and contact angle tests. Although the addition of acetylated cellulose did not change the crystalline structure and comprehensive performance of the composite fiber, it mainly disturbed molecular orientation of amorphous region, crystallinity and grain size. Besides the strengthening of hydrogen bonding between the two components, and the transverse connection between the aggregates were enhanced, thus reducing fibrillation. This paper provides a green modification approach that can be scaled up for industrial application, aiming to mitigated fibrillation issues in lyocell fibers. [ABSTRACT FROM AUTHOR]

Multi-functional cysteine-targeting covalent warheads possess significant therapeutic potential in medicinal chemistry and chemical biology. Herein, we present novel unsaturated and asymmetric ketone (oxazolinosene) scaffolds that selectively conjugate cysteine residues of peptides and bovine serum albumin under normal physiological conditions. This unsaturated saccharide depletes GSH in NCI-H1299 cells, leading to anti-tumor effects in vitro. The acetyl group of the ketal moiety on the saccharide ring can be converted to other carboxylic acids in a one-pot synthesis. In this way, the loaded acid can be click-released during cysteine conjugation, making the oxazolinosene a potential multifunctional therapeutic agent. The reaction kinetic model for oxazolinosene conjugation to GSH is well established and was used to evaluate oxazolinosene reactivity. The aforementioned oxazolinosenes were stereoselectively synthesized via a one-step reaction of nitriles with saccharides and conveniently converted into a series of α, β-unsaturated ketone N-glycosides as prevalent synthetic building blocks. The reaction mechanisms of oxazolinosene synthesis were investigated through calculations and validated with control experiments. Overall, these oxazolinosenes can be easily synthesized and developed as cysteine-targeted covalent warheads carrying useful click-releasing groups. Multifunctional cysteine targeting covalent warheads possess significant therapeutic potential in medicinal chemistry and chemical biology. Here, the authors develop an oxazolinosene scaffold from nitrile groups and saccharides that can selectively conjugate cysteine residues within peptides and proteins under physiological conditions, as well as deplete glutathione in cancer cells. [ABSTRACT FROM AUTHOR]

Extracellular polysaccharides (EPS) produced by Lactic Acid Bacteria have an individual effect on the flavour and consistency of novel food materials, as well as potential therapeutic applications. The purpose of this study was to create, improve, and characterise EPS from Lactobacillus amylovorus MTCC 8129. FTIR examination showed the compound's composition (acetyl group, hydroxy group, ring structure) as well as the numerous interlinks between sugar residues, which were then validated by Nuclear Magnetic Resonance Spectroscopy. Thermogravimetric examination showed that the EPS exhibited resistance to heat at a temperature of 640 °C, with antioxidant levels ranging from 70 to 85% and emulsification activity above 50%. Furthermore, it has 180% water holding capacity and 140% oil holding capacity. Based on these findings, it seems that the EPS that was reviewed might potentially be an advantageous addition to the food processing industry. [ABSTRACT FROM AUTHOR]

This document discusses the potential of lignocellulosic biomass (LCB) as a sustainable energy resource for the production of biofuels and biochemicals. LCB is primarily composed of cellulose, hemicellulose, and lignin, which can be converted into fermentable sugars through pretreatment and enzymatic hydrolysis. However, the complexity of LCB hydrolysates poses challenges for fermentation efficiency and product quality. The document highlights a special issue that explores various technological advancements in the biorefinery process of LCB decomposition and bioconversion, including pretreatment methods, biochemical production, functional saccharide products, and fermentation process optimization. These studies contribute to the efficient utilization of LCB and the advancement of the biorefinery industry. [Extracted from the article]

Degradation of heparan sulfate (HS), a glycosaminoglycan (GAG) comprised of repeating units of N-acetylglucosamine and glucuronic acid, begins in the cytosol and is completed in the lysosomes. Acetylation of the terminal non-reducing amino group of α-D-glucosamine of HS is essential for its complete breakdown into monosaccharides and free sulfate. Heparan-α-glucosaminide N-acetyltransferase (HGSNAT), a resident of the lysosomal membrane, catalyzes this essential acetylation reaction by accepting and transferring the acetyl group from cytosolic acetyl-CoA to terminal α-D-glucosamine of HS in the lysosomal lumen. Mutation-induced dysfunction in HGSNAT causes abnormal accumulation of HS within the lysosomes and leads to an autosomal recessive neurodegenerative lysosomal storage disorder called mucopolysaccharidosis IIIC (MPS IIIC). There are no approved drugs or treatment strategies to cure or manage the symptoms of, MPS IIIC. Here, we use cryo-electron microscopy (cryo-EM) to determine a high-resolution structure of the HGSNATacetyl-CoA complex, the first step in the HGSNAT-catalyzed acetyltransferase reaction. In addition, we map the known MPS IIIC mutations onto the structure and elucidate the molecular basis for mutation-induced HGSNAT dysfunction. [ABSTRACT FROM AUTHOR]

Excited‐state intramolecular proton transfer (ESIPT) molecules, which feature large Stokes shifts to avoid self‐absorption, play an essential role in photoluminescent bioimaging probes. Herein, we report the development of an ESIPT molecule 3‐(3‐hydroxypyridin‐2‐yl)isoquinolin‐4‐ol (PiQ). PiQ not only undergoes a distinct ESIPT process unlike the symmetrical 2,2′‐bipyridyl‐3,3′‐diol but also exhibits aggregation‐induced emission (AIE) characteristics. PiQ self‐assembles into aggregates with an average size of 241.0±51.9 nm in aqueous solutions, leading to significantly enhanced photoluminescence. On the basis of the ESIPT and AIE characteristics of PiQ, the latter is functionalized with a hydrogen peroxide‐responsive 4‐pinacoratoborylbenzyl group (B) and a carboxylesterase‐responsive acetyl group (A) to produce a photoluminescent probe B−PiQ−A. The potential of PiQ for applications in bioimaging and chemical sensing is underscored by its efficient detection of both endogenous and exogenous hydrogen peroxide in living cells. [ABSTRACT FROM AUTHOR]

The food industry extensively uses chemically modified starches and their hydrolysates, which is mainly due to their emulsification ability. Therefore, it becomes inevitable to develop new starch derivatives, including modified starch hydrolysates, and effective preparation methods to meet the increasing demands of producers, consumers, and technology. This study comprehensively researches the physical, chemical, and functional properties (such as the water-binding capacity, swelling power, solubility, and fat absorption capacity) of chemically modified biopolymers and their enzymatic hydrolysis products. We utilized oxidized and acetylated potato and waxy-corn starches with varying degrees of substitution by carboxyl and acetyl groups in our research. The process of enzymatic hydrolysis was performed in a recirculated membrane reactor (CRMR). Our findings indicated that the physicochemical properties of starch derivatives and their hydrolysates depended on the biological origin of the biopolymer and the type and degree of modification. However, the presence of carboxyl groups in the modified starch molecules is critical and affects the rheological properties and water-binding capacity of the starch preparations. For example, in the case of waxy-corn starch preparations with a lower content of carboxyl groups (i.e., derivatives with a low degree of oxidation), the water-binding capacity (WBC) increases when compared to native starch. The highest WBC value of 206.3% was noted for the doubly modified waxy-corn starch with an oxidation degree of 0.2% and an acetylation degree of 2.5%, while native waxy-corn starch shows a WBC of 161.4%. In contrast, it was observed that preparations with a higher content of carboxyl groups, i.e., derivatives with an oxidation degree of 2.5%, show a lower swelling power compared to native waxy starch. [ABSTRACT FROM AUTHOR]

Lysine acetylation is an evolutionarily conserved protein modification that changes protein functions and plays an essential role in many cellular processes, such as central metabolism, transcriptional regulation, chemotaxis, and pathogen virulence. It can alter DNA binding, enzymatic activity, proteinprotein interactions, protein stability, or protein localization. In prokaryotes, lysine acetylation occurs non-enzymatically and by the action of lysine acetyltransferases (KAT). In enzymatic acetylation, KAT transfers the acetyl group from acetyl-CoA (AcCoA) to the lysine side chain. In contrast, acetyl phosphate (AcP) is the acetyl donor of chemical acetylation. Regardless of the acetylation type, the removal of acetyl groups from acetyl lysines occurs only enzymatically by lysine deacetylases (KDAC). KATs are grouped into three main superfamilies based on their catalytic domain sequences and biochemical characteristics of catalysis. Specifically, members of the GNAT are found in eukaryotes and prokaryotes and have a core structural domain architecture. These enzymes can acetylate small molecules, metabolites, peptides, and proteins. This review presents current knowledge of acetylation mechanisms and functional implications in bacterial metabolism, pathogenicity, stress response, translation, and the emerging topic of protein acetylation in the gut microbiome. Additionally, the methods used to elucidate the biological significance of acetylation in bacteria, such as relative quantification and stoichiometry quantification, and the genetic code expansion tool (CGE), are reviewed. [ABSTRACT FROM AUTHOR]

This study explores the upcycling of cotton residues from textile industry as a feedstock in a biorefinery model. The proposed process is to enzymatically digest the crude biomass to produce bioethanol, transforming the non-hydrolyzed residue into both carboxymethylcellulose (CMC) and cellulose acetate (CA). Enzymatic hydrolysis experiments of the raw cotton (without any chemical pretreatment) were performed in batch mode to evaluate the effects of enzyme dosage and biomass concentrations. The highest glucose level (113.2 g/L) was obtained with 20% m/v biomass concentration and 15 FPU/gbiomass, corresponding to 46.8% cellulose-to-glucose conversion. Fed-batch strategies (substrate feeding (S1) or substrate and enzyme feeding (S2)) were also studied. 60.2% cellulose-to-glucose conversion was achieved for S2 strategy with substrate and enzyme feeding within the first 48 h. Both CMC and CA were successfully synthesized (degree of substitution equal to 2 and 3, respectively) from the remaining cotton, which indicates the introduction of two carboxymethyl groups in the hydroxyls of each glycosidic unit of cellulose in CMC and three acetyl groups in the case of CA. Using the best condition, it would be possible to estimate a yield of 301.2, 237, and 238 g of ethanol, CMC, and CA, respectively, per 1 kg of cotton scraps. The proposed route shows the viability of upcycling cotton waste into biofuels and bioproducts, driving the circular economy and fostering the textile industry. [ABSTRACT FROM AUTHOR]

We employed an amide photo‐Fries rearrangement for the synthesis benzoheterocyclic compounds and found that direct acylation of the α‐carbon atom in an arene ring can occur upon exposure to ultraviolet (UV) light. In this reaction, the N‐acetyl group of amides underwent rearrangement to the α‐position across the bridgehead carbon atom under UV−C light. The reaction conditions were gentle and safe. Moreover, this reaction proves to be more convenient for selectively manipulating benzoheterocyclic compounds in comparison to traditional approaches involving Lewis acid catalysts or anionic reagents. [ABSTRACT FROM AUTHOR]

The development of eco-friendly and biodegradable biopolymer composites has become increasingly important. In this study, acetylated lignin (ACL) was synthesized, and its potential as an effective additive for biodegradable polymers was investigated. ACL was synthesized through a one-step acetylation process in which hydroxyl groups of lignin were substituted with acetyl groups. ACL exhibited enhanced molecular weight and thermal stability, along with improved solubility in organic solvents compared to unmodified kraft lignin (KL). Hydrophobic ACL was uniformly dispersed in a mixture of a polycaprolactone (PCL) polymer and organic solvent, leading to the successful fabrication of a fibrous mat using electrospinning. The ACL/PCL fibrous mat demonstrated enhanced mechanical strength and hydrophobicity, notably indicating a substantially high-water contact angle of 143.3 ± 1.4°. Subsequently, it was utilized as a water/oil separator, showing a separation efficiency exceeding 90% for oil within a short time, effectively addressing water/oil emulsions. Biodegradability results demonstrated enhanced hydrolysis degradation efficiency with the incorporation of ACL into PCL fibers. Consequently, this study proposes a feasible approach to enhance the efficacy of ACL as a biodegradable polymer additive, while presenting promising opportunities for membrane applications targeting water/oil separation. [ABSTRACT FROM AUTHOR]

Heparan sulfate (HS) is degraded in lysosome by a series of glycosidases. Before the glycosidases can act, the terminal glucosamine of HS must be acetylated by the integral lysosomal membrane enzyme heparan-α-glucosaminide N-acetyltransferase (HGSNAT). Mutations of HGSNAT cause HS accumulation and consequently mucopolysaccharidosis IIIC, a devastating lysosomal storage disease characterized by progressive neurological deterioration and early death where no treatment is available. HGSNAT catalyzes a unique transmembrane acetylation reaction where the acetyl group of cytosolic acetyl-CoA is transported across the lysosomal membrane and attached to HS in one reaction. However, the reaction mechanism remains elusive. Here we report six cryo-EM structures of HGSNAT along the reaction pathway. These structures reveal a dimer arrangement and a unique structural fold, which enables the elucidation of the reaction mechanism. We find that a central pore within each monomer traverses the membrane and controls access of cytosolic acetyl-CoA to the active site at its luminal mouth where glucosamine binds. A histidine-aspartic acid catalytic dyad catalyzes the transfer reaction via a ternary complex mechanism. Furthermore, the structures allow the mapping of disease-causing variants and reveal their potential impact on the function, thus creating a framework to guide structure-based drug discovery efforts. HGSNAT is a critical lysosomal membrane enzyme involved in the devastating lysosomal storage disease Sanfilippo syndrome. Here, Zhao et. al. reveal the mechanism for transmembrane acetylation catalyzed by HGSNAT with a series of cryo-EM structures. [ABSTRACT FROM AUTHOR]

This article discusses the synthesis of hydroxyl-terminated polybutadiene (HTPB) using ring-opening metathesis polymerization (ROMP) and different olefin metathesis catalysts. The authors investigated the use of various catalysts, including Grubbs first-generation catalyst (G1), Grubbs second-generation catalyst (G2), Grubbs third-generation catalyst (G3), Hoveyda-Grubbs second-generation catalyst (HG2), and a Z-selective olefin metathesis catalyst (HGZ). They found that G3 produced the most promising results, with rapid monomer conversion and relatively high end-group fidelity. The other catalysts required longer reaction times and produced greater aldehyde formation. The study suggests that rapidly initiating olefin metathesis catalysts like G3 may offer advantages for ROMP with a chain-transfer agent. [Extracted from the article]

Diabetes mellitus is a chronic disease that impairs metabolism, and its prevalence has reached an epidemic proportion globally. Most people affected are with type 2 diabetes mellitus (T2DM), which is caused by a decline in the numbers or functioning of pancreatic endocrine islet cells, specifically the β-cells that release insulin in sufficient quantity to overcome any insulin resistance of the metabolic tissues. Genetic and epigenetic factors have been implicated as the main contributors to the T2DM. Epigenetic modifiers, histone deacetylases (HDACs), are enzymes that remove acetyl groups from histones and play an important role in a variety of molecular processes, including pancreatic cell destiny, insulin release, insulin production, insulin signalling, and glucose metabolism. HDACs also govern other regulatory processes related to diabetes, such as oxidative stress, inflammation, apoptosis, and fibrosis, revealed by network and functional analysis. This review explains the current understanding of the function of HDACs in diabetic pathophysiology, the inhibitory role of various HDAC inhibitors (HDACi), and their functional importance as biomarkers and possible therapeutic targets for T2DM. While their role in T2DM is still emerging, a better understanding of the role of HDACi may be relevant in improving insulin sensitivity, protecting β-cells and reducing T2DM-associated complications, among others. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

The hydroxypropyl chitosan (HPCH) and hydroxyethyl chitosan (HECH) are multifunctional chitosan derivatives with biocompatible and biodegradable properties. Due to their hydroxypropyl and hydroxethyl groups, they have water solubility, moisture retention, and gelling properties. In this study, the chitosan derivatives HPCH and HECH were obtained in two steps alkalisation and etherification. For alkalisation, chitosan was kept in an alkaline medium at -18C for 7 days. For etherification; the reaction was carried out for 48 hours by mixing alkaline chitosan with propylene oxide and ethylene oxide separately in a pressure reactor. The structures of the obtained HPCH and HECH were characterised by FT-IR, 1H(13C)-NMR, XRD, and TG analysis methods. Since the degree of deacetylation (DA) of chitosan is 75-85%, the chitosan units contain N-acetyl (-N-(CO)-CH3)) groups in addition to NH2 functional groups. When the 1H(13C)-NMR spectrum of chitosan was examined, the peak value of these acetyl groups was observed at δ1.89 ppm. When the XRD spectra were examined, it was observed that the strong peak in chitosan at 2θ-20° was weakened in HPCH and HECH. In addition, the thermal stability of HPCH and HECH was found to be higher than chitosan in TG analysis. [ABSTRACT FROM AUTHOR]

Polysaccharides are biomacromolecular widely applied in the food industry, as gelling agents, thickeners and health supplements. As hydrophobic groups, acetyls provide amphiphilicity to polysaccharides with numerous hydroxyl groups, which greatly expand the presence of polysaccharides in organic organisms and various chemical environments. Acetylation could result in diverseness and promotion of the structure of polysaccharides, which improve the physicochemical properties and biological activities. High efficient and environmentally friendly access to acetylated derivatives of different polysaccharides is being explored. This review discusses and summarizes acetylated polysaccharides in terms of synthetic methods, physicochemical properties and biological activities and emphasizes the structure-effect relationships introduced by acetyl groups to reveal the potential mechanism of acetylated polysaccharides. Acetyls with different contents and substitution sites could change the molecular weight, monosaccharide composition and spatial architecture of polysaccharides, resulting in differences among properties such as water solubility, emulsification and crystallinity. Coupled with acetyls, polysaccharides have increased antioxidant, immunomodulatory, antitumor, and pro-prebiotic capacities. In addition, their possible applications have also been discussed in green food materials, bioactive ingredient carriers and functional food products, indicating that acetylated polysaccharides hold a clear vision in food health and industrial development. Different catalysts and reagents could be chosen for acetylated polysaccharides preparation. Changes in structure properties of acetyl groups can affect physical and biological activities. Acetylated polysaccharides possess a lot of improved biological activities. Acetylated polysaccharides have great potential in food, pharmaceutical and biomaterial areas. [ABSTRACT FROM AUTHOR]

Histone deacetylases (HDACs) are crucial in gene transcription, removing acetyl groups from histones. They also influence the deacetylation of non-histone proteins, contributing to the regulation of various biological processes. Thus, HDACs play pivotal roles in various diseases, including cancer, neurodegenerative disorders, and inflammatory conditions, highlighting their potential as therapeutic targets. This paper reviews the structure and function of the four classes of human HDACs. While four HDAC inhibitors are currently available for treating hematological malignancies, numerous others are undergoing clinical trials. However, their non-selective toxicity necessitates ongoing research into safer and more efficient class-selective or isoform-selective inhibitors. Computational methods have aided the discovery of HDAC inhibitors with the desired potency and/or selectivity. These methods include ligand-based approaches, such as scaffold hopping, pharmacophore modeling, three-dimensional quantitative structure–activity relationships, and structure-based virtual screening (molecular docking). Moreover, recent developments in the field of molecular dynamics simulations, combined with Poisson–Boltzmann/molecular mechanics generalized Born surface area techniques, have improved the prediction of ligand binding affinity. In this review, we delve into the ways in which these methods have contributed to designing and identifying HDAC inhibitors. [ABSTRACT FROM AUTHOR]

Sirtuins (SIRTs) are classified as class III histone deacetylases (HDACs), a family of enzymes that catalyze the removal of acetyl groups from the ε-N-acetyl lysine residues of histone proteins, thus counteracting the activity performed by histone acetyltransferares (HATs). Based on their involvement in different biological pathways, ranging from transcription to metabolism and genome stability, SIRT dysregulation was investigated in many diseases, such as cancer, neurodegenerative disorders, diabetes, and cardiovascular and autoimmune diseases. The elucidation of a consistent number of SIRT–ligand complexes helped to steer the identification of novel and more selective modulators. Due to the high diversity and quantity of the structural data thus far available, we reviewed some of the different ligands and structure-based methods that have recently been used to identify new promising SIRT1/2 modulators. The present review is structured into two sections: the first includes a comprehensive perspective of the successful computational approaches related to the discovery of SIRT1/2 inhibitors (SIRTIs); the second section deals with the most interesting SIRTIs that have recently appeared in the literature (from 2017). The data reported here are collected from different databases (SciFinder, Web of Science, Scopus, Google Scholar, and PubMed) using "SIRT", "sirtuin", and "sirtuin inhibitors" as keywords. [ABSTRACT FROM AUTHOR]

Dendrobium nobile Lindl. polysaccharide (DNP1) showed good anti-inflammatory activity in our previous study. In this study, the structural characterization of DNP1 and its mode of action on TLR4 were investigated. Structural characterization suggested that DNP1 was a linear glucomannan composed of (1 → 4)-β-Manp and (1 → 4)-β-Glcp residues, and the acetyl group was linked to the C-2 of Manp. The possible repeating structural units of DNP1 were [→4)-2-OAc-β-Manp-(1→]3 →4)-β-Glcp-(1→. Surface plasmon resonance (SPR) binding test results showed that DNP1 did not bind directly to TLR4. The TLR4 and MD2 receptor blocking tests confirmed that DNP1 needs MD2 and TLR4 to participate in its anti-inflammatory effect. The binding energy of DNP1 to TLR4-MD2 was −7.9 kcal/mol, indicating that DNP1 could bind to the TLR4-MD2 complex stably. Therefore, it is concluded that DNP1 may play an immunomodulatory role by binding to the TLR4-MD2 complex and inhibiting the TLR4-MD2-mediated signaling pathway. [ABSTRACT FROM AUTHOR]

Sirt2 is a nicotinamide adenine dinucleotide (NAD+)- dependent protein lysine deacylase that can remove both acetyl group and long- chain fatty acyl groups from lysine residues of many proteins. It was reported to affect inflammatory bowel disease (IBD) symptoms in a mouse model. However, conflicting roles were reported, with genetic knockout aggravating while pharmacological inhibition alleviating IBD symptoms. These seemingly conflicting reports cause confusion and deter further efforts in developing Sirt2 inhibitors as a potential treatment strategy for IBD. We investigated these conflicting reports and elucidated the role of Sirt2 in the mouse model of IBD. We essentially replicated these conflicting results and confirmed that Sirt2 inhibitors' protective effect is not through off- targets as two very different Sirt2 inhibitors (TM and AGK2) showed similar protection in the IBD mouse model. We believe that the differential effects of inhibitors and knockout are due to the fact that the Sirt2 inhibitors only inhibit some but not all the activities of Sirt2. This hypothesis is confirmed by the observation that a PROTAC degrader of Sirt2 did not protect mice in the IBD model, similar to Sirt2 knockout. Our study provides an interesting example where genetic knockout and pharmacological inhibition do not align and emphasizes the importance of developing substrate- dependent inhibitors. Importantly, we showed that the effect of Sirt2 inhibition in IBD is through regulating the gut epithelium barrier by inhibiting Arf6- mediated endocytosis of E- cadherin, a protein important for the intestinal epithelial integrity. This mechanistic understanding further supports Sirt2 as a promising therapeutic target for treating IBD. [ABSTRACT FROM AUTHOR]

In this study, silver birch (Betula pendula) and Scots pine (Pinus sylvestris) wood planks (1000 × 100 × 25 mm) were thermally modified in pilot-scale equipment. Research extended our knowledge of the thermal modification (TM) process in a closed system under nitrogen pressure, as well as how process parameters affect the chemical composition and mechanical strength of wood. Various TM regimes were selected—maximum temperature (150–180 °C), modification time (30–180 min), and initial nitrogen pressure (3–6 bar). Chemical analyses were performed to assess the amount of extractives, lignin, polysaccharides and acetyl group content following the TM process. The mechanical properties of TM wood were characterized using the modulus of rupture (MOR), modulus of elasticity (MOE), and Brinell hardness. The MOR of both studied wood species following TM in nitrogen was reduced, but MOE changes were insignificant. The Brinell hardness of TM birch wood's tangential surface was much higher than that of the radial surface, although Scots pine wood showed the opposite pattern. TM birch and pine wood specimens with the highest mass loss, acetone soluble extractive amount, and the lowest xylan and acetyl group content had the lowest MOR and Brinell hardness. [ABSTRACT FROM AUTHOR]

Histone deacetylases (HDACs) are enzymes that remove acetyl groups from ɛ-amino of histone, and their involvement in the development and progression of cancer disorders makes them an interesting therapeutic target. This study seeks to discover new inhibitors that selectively inhibit HDAC enzymes which are linked to deadly disorders like T-cell lymphoma, childhood neuroblastoma, and colon cancer. MOE was used to dock libraries of ZINC database molecules within the catalytic active pocket of target HDACs. The top three hits were submitted to MD simulations ranked on binding affinities and well-occupied interaction mechanisms determined from molecular docking studies. Inside the catalytic active site of HDACs, the two stable inhibitors LIG1 and LIG2 affect the protein flexibility, as evidenced by RMSD, RMSF, Rg, and PCA. MD simulations of HDACs complexes revealed an alteration from extended to bent motional changes within loop regions. The structural deviation following superimposition shows flexibility via a visual inspection of movable loops at different timeframes. According to PCA, the activity of HDACs inhibitors induces structural dynamics that might potentially be utilized to define the nature of protein inhibition. The findings suggest that this study offers solid proof to investigate LIG1 and LIG2 as potential HDAC inhibitors. [ABSTRACT FROM AUTHOR]

This article provides a comprehensive overview of recent advances in the synthesis of C-glycosides, which are compounds that contain a carbon-carbon bond between the sugar moiety and another group. The text discusses various synthetic routes and reactions, such as the carbon-Ferrier rearrangement, that have been used to synthesize C-glycosides. These compounds have potential applications in the development of therapeutics and have shown promising antimicrobial and antiviral activity. The article also highlights the potential applications of C-glycosides in medicinal chemistry and the synthesis of natural products. [Extracted from the article]

A cellulose acetate (CA) membrane as an acetylation product of bacterial cellulose (BC) has been successfully fabricated by electrospinning (e-spin). CA was utilized to achieve the optimal polymer electrolytes' (SPEs) requirements of high ionic conductivity and good thermal and electrochemical stability. E-spin has received a great deal of attention in order to enhance the surface of membranes that is both flexible and strong, which will be effective in obtaining a low interface resistance for a better contact polymer electrolyte/electrode. The e-spin of CA SPEs forms a three-dimensional network of interconnected porosity. Polar ester groups in CA e-spin not only present the homogeny porosity of the SPEs but also played an important role in facilitating the dissociation of lithium bis(trifluoromethanesulfonyl)imide (LiTFSI). According to XPS, peaks of TFSI binding energy CA that are higher than BC are thought to represent the interaction between the polymer chain and the TFSI cation. TFSI− was found to have accumulated around C=O, and Li+ could diffuse quickly. This is supported by the fact that the ionic conductivity (2.68 × 10−3 Scm−1) of CA is better than BC (8.86 × 10−4 Scm−1). The change in dielectric permittivity (ε) as a function of frequency in CA SPEs shows more decay at higher frequencies, indicating better electrode polarization due to CA SPE/electrode contact than BC. The analysis of the modulus (M) shows that CA SPEs in this study are more ionic conductors than BC. CA SPEs also outperformed BC in terms of stability window performance (4.5 V). The discharge capacities of 40 mA h−1 for CA SPEs exhibit an oxidation peak at 4.25 V and a reduction peak at 2.9 V, which are comparatively higher than the charge–discharge of 20 mA h−1 for BC SPEs, which display an oxidation peak at 3.5 V and a reduction peak at 2.8 V. [ABSTRACT FROM AUTHOR]

A convergent synthesis of the dodecasaccharide scaffold of axinelloside A was achieved through Au(I)‐catalyzed [6+6] glycosylation. The initially devised [3+1+2] assembly of the nonreducing hexasaccharide fragment was low‐yielding, whereas a convergent [3+3] glycosylation under Au(I) catalysis was proven feasible, allowing for a semi‐gram scale preparation of the wanted hexasaccharide. The requisite 1,2‐cis glycosidic bonds were forged in a highly stereoselective fashion by virtue of remote acetyl group participation, and judicious manipulation of protecting groups. The synthetic dodecasaccharide has been properly protected for the downstream elaboration toward its natural form. [ABSTRACT FROM AUTHOR]

Nanocomposite membranes based on electrospun-cellulose (EC) composites combined with cerium oxide (CeO2) nanoparticles (NPs) were fabricated by electrospinning using cellulose acetate (CA) as a precursor. CeO2 NPs were initially synthesized via cellulose nitrate template. After removing the template and any residual by calcination at 500 °C, the nanocubic CeO2 NPs were obtained with average sizes of 20.40 ± 3.8 nm and then incorporated into cellulose nanofibers (CNFs) by mixing with CA solution. Subsequently, the obtained CA/CeO2 nanocomposite membrane was formed via the electrospinning and then converted to the EC/CeO2 nanocomposite membrane by being treated with a NaOH ethanolic solution. FTIR analysis confirmed the stepwise conversion of the acetyl group in CA structure to the hydroxyl groups of cellulose. The fabricated nanocomposite membranes characterized via FE-SEM and AFM, evaluating that the addition of CeO2 NPs incorporated into the fabricated CNFs resulted in changing their average fiber diameter without the exfoliation of CeO2 NPs. The average fiber diameter of the EC and EC/CeO2 nanocomposite membranes with 0.5, 1.0, and 1.5 wt% CeO2 contents was estimated to be 206 ± 66, 189 ± 47, 178 ± 52, and 147 ± 108 nm, respectively. However, it was observed that, at 1.5 wt% of CeO2 NP contents, the bead-like formation appeared, leading to enhancement of water uptake capacities up to 260.11 ± 15.93%, meanwhile the EC membrane exhibited the water uptake capacities of 203.77 ± 11.11%. In addition, the antibacterial activity of EC nanocomposite membranes was conducted against Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli). The results indicated that incorporating CeO2 NPs into the CNF matrix via electrospinning does not exhibit the distinct antibacterial activities of EC. The effect of the CeO2 NPs incorporated in EC nanocomposite membranes was further discussed. [ABSTRACT FROM AUTHOR]

This article discusses the collective total synthesis of β-carboline-type monoterpenoid indole alkaloid glycosides. These alkaloids are found in higher plants and have medicinal applications. The authors describe the synthesis of several specific alkaloids, including lyaloside, ophiorines A and B, and correantosine F. They also detail the development of a new decyanation/oxidation reaction using a cyano group, which allows for the efficient synthesis of β-carboline compounds. The authors successfully synthesized these alkaloids and are currently evaluating their bioactivity. [Extracted from the article]

New arylamide- and arylthiourea-based chiral solvating agents (CSAs) were synthesized starting from commercially available isomannide and isosorbide. The two natural isohexides were transformed into the three amino derivatives, having isomannide, isosorbide, and isoidide stereochemistry, then the amino groups were derivatized with 3,5-dimethoxybenzoyl chloride or 3,5-bis(trifluoromethyl)phenyl isothiocyanate to obtain the CSAs. Bis-thiourea derivative containing the 3,5-bis(trifluoromethyl)phenyl moiety with exo–exo stereochemistry was remarkably efficient in the differentiation of NMR signals (NH and acetyl) of enantiomers of N-acetyl (N-Ac) amino acids in the presence of 1,4-diazabicyclo[2,2,2]octane (DABCO). Nonequivalences in the ranges of 0.104–0.343 ppm and 0.042–0.107 ppm for NH and acetyl groups, respectively, allowed for very accurate enantiomeric excess determination, and a reliable correlation was found between the relative positions of signals of enantiomers and their absolute configuration. Therefore, a complete stereochemical characterization could be performed. Dipolar interactions detected in the ternary mixture CSA/N-Ac-valine/DABCO led to the identification of a different interaction model for the two enantiomers, involving the formation of a one-to-one substrate/CSA complex for (S)-N-Ac-valine and a one-to-two complex for (R)-N-Ac-valine, as suggested by the complexation stoichiometry. [ABSTRACT FROM AUTHOR]

The title compound, C14H12N2O4, was obtained from 2-acetyl-6-aminonaphthalene through two-step reactions of acetylation and nitration. The molecule comprises the naphthalene ring system consisting of functional systems bearing a acetyl group (C-2), a nitro group (C-5), and an acetylamino group (C-6). In the crystal, the molecules are assembled into two-dimensional sheetlike structures by intermolecular N--H⋯O and C--H⋯O hydrogen-bonding interactions. Hirshfeld surface analysis illustrates that the most important contributions to the crystal packing are from O⋯H/H⋯O (43.7%), H⋯H (31.0%), and C⋯H/H⋯C (8.5%) contacts. [ABSTRACT FROM AUTHOR]

This article provides a comprehensive overview of synthetic approaches to gliflozins, a class of drugs used to treat diabetes mellitus. It discusses different types of diabetes, management strategies, and various therapeutic agents available. The article focuses on the synthesis of specific gliflozins, highlighting different routes and their yields. The information presented is valuable for researchers studying diabetes and the development of antidiabetic drugs. It also mentions the approval and effectiveness of certain gliflozins in the treatment of diabetes. [Extracted from the article]

Houttuynia cordata Thunb (H. cordata) is a medicinal and edible homologous plant. The abundant water-soluble polysaccharides of H. cordatahave been proved to have a variety of biological activities. However, the current research on polysaccharides from H. cordata mainly focuses on the whole plant or aboveground parts. The differences in the structure and activity of polysaccharides from different parts of H. cordataare rarely reported. In this study, the polysaccharides from the rhizome (RHCP), stem (SHCP) and leaf (LHCP) of H. cordata were extracted and separated, and their structural characterization, antioxidant activity in vitro and α-glucosidase inhibitory activity were determined. The aim was to explore the relationship between the structure and biological activity of H. cordata polysaccharides (HCPs). Results showed that polysaccharides in different parts of H. cordata were acidic polysaccharides, which were composed of glucose, galactose, arabinose, rhamnose, galactose uronic acid, and a small amount of fucose, mannose, xylose, and glucuronic acid, but the proportions are different; The molecular weight was 4.11 x104 u to 1.20x104 u; The infrared structure was basically the same; LHCP had higher content of methyl and acetyl groups, and their contents were 0.95% and 1.05% respectively; The surface morphology of the three polysaccharides was smooth and flat; LHCP was not triple helix polysaccharide, while RHCP and SHCP existed triple helical structure. The in vitro antioxidant and °-glucosidase inhibition ability of LHCP were the strongest. It was found that the structure and activity of polysaccharides from different parts of H. cordata were different, providing a theoretical basis for the study of the structure -activity relationship of HCPs and providing a theoretical basis for the development and utilization of HCPs. [ABSTRACT FROM AUTHOR]

The effects of acetyl groups in dendrobium polysaccharide (DOP) on gel properties and antioxidant capacity have not been reported in the literature. In this study, we prepared DOP with different degrees of deacetylation by non- homogeneous deacetylation, analyzed its fluid properties, textural properties and total antioxidant capacity of sol and gel, and investigated the effect of acetyl group on the properties of DOP and its mechanism of action. The results showed that the presence of acetyl group made the DOP have good water solubility. With the increase of deacetylation, the viscosity of the sol decreased and the gel formation rate was faster, which changed the thermal sensitivity of the sol when forming the gel and improved the hardness and elasticity of the DOP gel significantly. In addition, the results also showed that the removal of some acetyl groups significantly improved the total antioxidant capacity. Therefore, the rheological and textural properties as well as antioxidant properties of DOP can be adjusted by controlling the amount of acetyl groups of DOP. This study may provide new ideas for the application of DOP in food, pharmaceutical and chemical industries. [ABSTRACT FROM AUTHOR]

In the rotational spectroscopy community, several popular codes are available to treat multiple internal rotors in a molecule. In terms of the pros and cons of each code, it is often a difficult task to decide which program to apply to a specific internal rotation problem. We faced this issue when dealing with the spectroscopic fingerprint of 4-methylacetophenone (4MAP), recently investigated in the microwave region, which we here extended into the millimeterwave region. The methyl group attached to the phenyl ring in 4MAP undergoes internal rotation with a very low barrier of only 22 cm−1. The acetyl methyl group features a much higher barrier of about 580 cm−1. The performances of a program using the so-called "local" approach in terms of Herschbach's perturbative treatment, SPFIT, as well as three programs XIAM, ERHAM, and ntop, representing "global" fits, were tested. The results aim at helping spectroscopists in the decision on how to tackle their own internal rotation problems. [ABSTRACT FROM AUTHOR]

As a new type of green photothermal material, lignin exhibits an excellent photothermal effect due to its abundant aromatic rings and π–π conjugated structure. To develop value-added applications of lignin in the photothermal field, it is important to explore strategies for regulating the photothermal conversion of lignin. In this work, the photothermal effect of lignin was improved significantly through modification with an electron-withdrawing group. The introduction of acetyl resulted in the formation of an electron donor–acceptor (D–A) structure in lignin and enhanced the light absorption ability. The intermolecular interaction among lignin molecules also decreased after modification with acetyl groups, leading to enhanced non-radiative decay induced by molecular motion. Under 808 nm laser irradiation at 0.51 W cm−2, the photothermal conversion efficiency of acetylated lignin (ACAL) reached as high as 73.2%, which was 37% higher than that of unmodified lignin. This study provides a new strategy to enhance the photothermal effect of lignin and deepens the understanding of the lignin photothermal mechanism. [ABSTRACT FROM AUTHOR]

A monolayer of endothelial cells (ECs) lines the lumen of blood vessels and, as such, provides a semi-selective barrier between the blood and the interstitial space. Compromise of the lung EC barrier due to inflammatory or toxic events may result in pulmonary edema, which is a cardinal feature of acute lung injury (ALI) and its more severe form, acute respiratory distress syndrome (ARDS). The EC functions are controlled, at least in part, via epigenetic mechanisms mediated by histone deacetylases (HDACs). Zinc-dependent HDACs represent the largest group of HDACs and are activated by Zn2+. Members of this HDAC group are involved in epigenetic regulation primarily by modifying the structure of chromatin upon removal of acetyl groups from histones. In addition, they can deacetylate many non-histone histone proteins, including those located in extranuclear compartments. Recently, the therapeutic potential of inhibiting zinc-dependent HDACs for EC barrier preservation has gained momentum. However, the role of specific HDAC subtypes in EC barrier regulation remains largely unknown. This review aims to provide an update on the role of zinc-dependent HDACs in endothelial dysfunction and its related diseases. We will broadly focus on biological contributions, signaling pathways and transcriptional roles of HDACs in endothelial pathobiology associated mainly with lung diseases, and we will discuss the potential of their inhibitors for lung injury prevention. [ABSTRACT FROM AUTHOR]

The chemistry of 3-acetylquinoline has attracted increased attention in both synthetic organic and medicinal chemistry. The present review summarizes the published data on the synthesis of 3-acetylquinoline derivatives and their reactions, including reactions involving and not involving the acetyl group. [ABSTRACT FROM AUTHOR]

During growth, bacteria remodel and recycle their peptidoglycan (PG). A key family of PG-degrading enzymes is the lytic transglycosylases, which produce anhydromuropeptides, a modification that caps the PG chains and contributes to bacterial virulence. Previously, it was reported that the polar-growing Gram-negative plant pathogen Agrobacterium tumefaciens lacks anhydromuropeptides. Here, we report the identification of an enzyme, MdaA (MurNAc deacetylase A), which specifically removes the acetyl group from anhydromuropeptide chain termini in A. tumefaciens, resolving this apparent anomaly. A. tumefaciens lacking MdaA accumulates canonical anhydromuropeptides, whereas MdaA was able to deacetylate anhydro-N-acetyl muramic acid in purified sacculi that lack this modification. As for other PG deacetylases, MdaA belongs to the CE4 family of carbohydrate esterases but harbors an unusual Cys residue in its active site. MdaA is conserved in other polar-growing bacteria, suggesting a possible link be-tween PG chain terminus deacetylation and polar growth. [ABSTRACT FROM AUTHOR]

This article discusses the synthesis of N-{2-[4-(β-d-Glucopyranosyloxy)-2-methylphenyl]-1,1-dimethyl-2-oxoethyl}-3-methylthiophene-2-carboxamide (GPTC), a metabolite of the fungicide isofetamid. The authors describe the importance of certified reference materials (CRMs) for accurate analysis of toxic chemicals in food. They report a decagram-scale synthesis of GPTC to obtain a standard CRM for residue analysis in food. The synthesis involves several steps, including protection, amination, coupling, and glycosylation, resulting in the production of 25 grams of GPTC with a purity of 99.6%. The authors conclude that this synthetic approach can be used to establish a standard CRM for analyzing residues in food. [Extracted from the article]

A new compound, commikuanoid D, was isolated from the ethyl acetate fraction of Commiphora kua resin. The structure was unambiguously elucidated on the basis of complete spectroscopic analysis. Furthermore, the compound displayed potent carbonic anhydrase II inhibition with IC50 of 17.4 ± 0.32 μM. On the other hand, the molecular docking reflected that the acetyl group of the molecule specifically binds with the Zn ion at the active site of CA-II, and the OH group of the compound mediated hydrogen bonding with Gln92, thus blocking the enzyme activity with a good binding score (≥ 7 kcal/mol). [ABSTRACT FROM AUTHOR]

The presence of dyes in drainage water is one of the important problems that many seek to solve. This study included the preparation of the adsorbent surface using the oyster shells as a basis for the preparation of chitosan, which is a series of carbohydrates and saccharides, by treating them with some simple chemical reactions that grab the acetyl group (de-acetylation), which is a part of the structure of chitin. Then the basic formula of Chitosan is ready to carry positive charges, which act as magnet to attract molecules of any substance beside it. A series of assays were undertaken to assess the efficiency of the adsorption process, such as the weight of oyster shells, equilibrium time, effect of pH, initial concentration of toluidine blue dye, and particle size of the adsorbent. These experiments have shown that the equilibrium time was 120 min, the optimum weight of oyster shells was 0.1 g in 100 mL of dye solution, and the particle size was 150 µm. They also showed there is an effect of the pH on the adsorption of the dye. The adsorption isotherm was well fitted to both the Freundlich and Langmuir models. [ABSTRACT FROM AUTHOR]

The detailed anatomical and chemical features of the bark from endemic Quercus vulcanica in Turkey are reported here for the first time and discussed in the perspective of integration into a bark-based biorefinery system. The bark of Q. vulcanica trees was collected and studied through observations using light and scanning electron microscopy, wet-chemical analysis, inorganic elemental and FTIR analyses, GC–MS determinations of lipophilic extractives and suberin monomers, as well as TBARS antioxidant activity of hydroethanolic extracts. The bark of Q. vulcanica comprises phloem and a rhytidome with thin periderms and a few cork layers. The ash content is high (16.4%), primarily consisting of calcium oxalate crystals. Extractives were present in a high amount (23.1%) of which 88% corresponded to hydrophilic extractives (10.3% ethanol, and 10.1% water solubles). The suberin content is low (3.7%), which aligns with the small proportion of cork in the bark rhytidome. The composition of suberin is characterized by similar proportions of α, ω-alkanoic diacids and ω-hydroxyalkanoic acids, with 18-hydroxy-9-octadecenoic acid (26% of monomers) and octadec-9-enedioic acid (20.6%) as the main monomers. The lignin content is 21.9%, and the monomeric composition of polysaccharides includes glucose, xylose, arabinose, galactose, rhamnose, and acetyl groups. The lipophilic extractives are mainly composed of terpenoids (72.2% of all compounds), with friedelin and friedelanol as the main compounds. Hydroethanolic extracts, obtained under mild conditions with a yield of 10.2%, exhibited antioxidant activity (TBARS assay, EC50 value of 55 μg/mL). The overall chemical and structural properties of Q. vulcanica bark indicate promising potential for biorefineries. [ABSTRACT FROM AUTHOR]