Acid Function Research Articles

Fabrication and characterization approach to enhance the mechanical performance of zirconia‐coated Multi‐walled carbon nanotubes reinforced High density polyethylene composites

AbstractThis study presents a comprehensive investigation into the fabrication and characterization of high‐density polyethylene (HDPE) composites reinforced with zirconia (ZrO2)‐coated multi‐walled carbon nanotubes (MWCNTs). HDPE, a widely used polymer for pressure pipe applications, was selected for its superior mechanical properties, while ZrO2‐coated MWCNTs were employed as nanofillers to enhance these properties further. The acid functionalization of MWCNTs, followed by the application of a ZrO2 coating, was executed to ensure optimal dispersion and interfacial bonding within the HDPE matrix. The functionalized MWCNTs (f‐MWCNTs) were synthesized via an acid treatment process using 8 M HNO3, which significantly eased agglomeration and facilitated a stable ZrO2 coating. Subsequent hydrothermal processing at 200°C for 18 h yielded uniformly coated MWCNTs. These nanofillers were then melt‐blended with HDPE, followed by injection molding. Mechanical testing revealed substantial enhancements in the tensile, flexural, and hardness properties of the composites. The tensile strength exhibited a marked increase, peaking at a 3 wt.% ZrO2‐coated MWCNT concentration, with a 50% improvement over pristine HDPE. Flexural modulus and hardness values also saw significant increments, with the highest enhancements recorded at 4 wt.% filler content. Impact testing showed improved toughness, although excessive filler loading led to diminished returns due to nanoparticle aggregation. FTIR and XRD analyses supported the successful integration of ZrO2‐coated MWCNTs within the HDPE matrix, highlighting the presence of characteristic peaks associated with both MWCNTs and HDPE. These findings provide the potential of ZrO2‐coated MWCNTs as effective nanofillers in enhancing the mechanical performance of HDPE composites, making suitable for advanced engineering applications.Highlights Coating of ZrO2 on MWCNTs using Hydrothermal method. Melt blending of ZrO2 coated MWCNT with HDPE using twin‐screw extruder. Preparation of samples through injection molding as per ASTM standard. Mechanical properties and characterization analysis of the composite.

Discovery of anticancer peptides from natural and generated sequences using deep learning.

Anticancer peptides (ACPs) demonstrate significant potential in clinical cancer treatment due to their ability to selectively target and kill cancer cells. In recent years, numerous artificial intelligence (AI) algorithms have been developed. However, many predictive methods lack sufficient wet lab validation, thereby constraining the progress of models and impeding the discovery of novel ACPs. This study proposes a comprehensive research strategy by introducing CNBT-ACPred, an ACP prediction model based on a three-channel deep learning architecture, supported by extensive in vitro and in vivo experiments. CNBT-ACPred achieved an accuracy of 0.9554 and a Matthews Correlation Coefficient (MCC) of 0.8602. Compared to existing excellent models, CNBT-ACPred increased accuracy by at least 5% and improved MCC by 15%. Predictions were conducted on over 3.8 million sequences from Uniprot, along with 100,000 sequences generated by a deep generative model, ultimately identifying 37 out of 41 candidate peptides from >30 species that exhibited effective in vitro tumor inhibitory activity. Among these, tPep14 demonstrated significant anticancer effects in two mouse xenograft models without detectable toxicity. Finally, the study revealed correlations between the amino acid composition, structure, and function of the identified ACP candidates.

Enhanced ZBTB10 expression induced by betulinic acid inhibits gastric cancer progression by inactivating the ARRDC3/ITGB4/PI3K/AKT pathway.

Gastric cancer (GC) ranks as the fourth leading cause of cancer-related deaths worldwide, with most patients diagnosed at advanced stages due to the absence of reliable early detection biomarkers. RNA-sequencing was conducted to identify the differentially expressed genes between GC tissues and adjacent normal tissues. CCK8, EdU, colony formation, transwell, flow cytometry and xenograft assays were adopted to explore the biological function of ZBTB10 and betulinic acid (BA) in GC progression. RNA-sequencing and phospho-proteomic profiling were performed to analyze the signaling pathways associated with ZBTB10-inhibiting GC progression. Chromatin immunoprecipitation, Co-immunoprecipitation and luciferase reporter assay were employed to elucidate the potential molecular regulatory mechanisms of ZBTB10 in GC. ZBTB10 was one of the most significantly downregulated genes in GC tissues, and higher expression levels of ZBTB10 was correlated with better prognosis in patients with GC. Functional studies revealed that ZBTB10 overexpression and BA inhibited GC progression both in vitro and in vivo. Mechanistically, ZBTB10 enhanced ARRDC3 expression by binding to a specific response element in the ARRDC3 promoter region. Elevated ARRDC3 then directly interacted with β-4 integrin (ITGB4), leading to its ubiquitination and degradation. This cascade ultimately resulted in the downregulation of PI3K and AKT phosphorylation level. Moreover, ZBTB10 was a key target for BA in GC and BA inhibited GC progression through regulating the ZBTB10/ARRDC3/ITGB4/PI3K/AKT axis. Our findings reveal that BA holds promise as an effective therapeutic strategy for GC, and the ZBTB10/ARRDC3/ITGB4/PI3K/AKT axis may serve as a novel diagnostic and therapeutic target.

Effects and function of citric acid on fermentation quality and microbial community in sugarcane tops silage with high and low water-soluble carbohydrate content

Sugarcane tops silage (STS), as a source of roughage for ruminants, is rich in water-soluble carbohydrate (WSC) content, which significantly affects silage quality. Citric acid (CA) is a low-cost natural antimicrobial agent that can inhibit undesirable microbes and improve silage quality. The objectives of this study were to investigate the effects of CA on the chemical composition, fermentation quality, microbial communities, and metabolic pathways of STS with high and low WSC contents before or after aerobic exposure. Fresh sugarcane tops with low-WSC [143.05 g/kg dry matter (DM)] and high-WSC (249.99 g/kg DM) contents were treated with and without CA and then ensiled for 125 days, followed by aerobic exposure for 4, 8, and 16 days. The results showed that high-WSC STS had lower crude protein (CP) content and higher DM, neutral detergent fiber (NDF), and acid detergent fiber (ADF) contents, whether treated with CA or not. CA-inoculated silage exhibited decreased DM loss and enterobacteria (EB) counts compared to the control. High-WSC STS treated with CA had higher WSC content and lower yeast count than those without CA inoculation. During the 0–16 days of aerobic exposure, the propionic acid and butyric acid contents in CA-inoculated silage were almost unchanged and ranged from 0 to 1 g/kg DM. Meanwhile, the ethanol content was almost unchanged and ranged from 0 to 1 g/kg DM only in low-WSC STS, irrespective of CA addition. Before aerobic exposure, CA inoculation decreased the abundances of undesirable microbes (e.g., Clostridium_sensu_stricto_12 and Paecilomyces) and animal pathogens, while amino acid metabolism was lower in high-WSC STS regardless of CA treatment. After aerobic exposure, CA inoculation increased the abundance of bacteria with antibacterial effects, including Paenibacillus and Bacillus. Moreover, the metabolism of energy and nucleotides was lower in high-WSC STS treated with CA, and the animal pathogens was lower in low-WSC STS treated with CA. In conclusion, CA inoculation could be effective in decreasing nutrients loss, improving fermentation quality, inhibiting harmful microorganisms, and modulating the metabolic pathways of microorganisms in STS with high and low WSC contents prior to and after aerobic exposure.

GABA mitigates mitochondrial apoptosis induced by high temperature stress in the Pacific oyster (Crassostrea gigas).

High temperature is a critical environmental factor leading to mass mortality in oyster aquaculture in China. Recent advancements highlight the physiological regulation function of γ-aminobutyric acid (GABA) in the adaptation of environmental stress. This study examined the physiological responses of the Pacific oyster (Crassostrea gigas) upon high temperature exposure, focusing on the histopathological changes in gill, the GABA concentration, the mRNA expression and activities of apoptosis-related genes. Following 24h of exposure to seawater at 28°C, notable histopathological changes, including cellular swelling and vacuolization, along with an increase in TUNEL-positive cells were observed in the oyster gill, compared to the control group maintained at 18°C. Moreover, there was a significant increase in CgCaspase-3 transcripts, Caspase-3 and Caspase-9 activities in the gills, glutamate decarboxylase CgGAD transcripts in the haemocytes, and GABA concentrations in the haemolymph supernatant. Intervention with GABA markedly ameliorated these responses, including reducing the mRNA expression levels of CgBax, CgBak, CgCaspase-3, and CgCaspase-9, as well as the activities of Caspase-3/9. Furthermore, after the treatment with GABAA and GABAB receptor antagonists, the activities and expression levels of Caspase-3 and Caspase-9 significantly up-regulated under hightemperature stress. GABA treatment also significantly diminished the increased Caspase-3 activity by mitochondrial pathway apoptosis inducers. High temperature induced mitochondrial pathway apoptosis via increased caspase activities. The transcripts of CgGAD in haemocytes and GABA concentration in hemolymph supernatant also increased after high-temperature stress. GABA countered these effects through the activation of GABAA and GABAB receptors, reducing both caspase activity and expression of apoptosis-related genes.

Protection Strategies Against Palmitic Acid-Induced Lipotoxicity in Metabolic Syndrome and Related Diseases.

Diets rich in carbohydrate and saturated fat contents, when combined with a sedentary lifestyle, contribute to the development of obesity and metabolic syndrome (MetS), which subsequently increase palmitic acid (PA) levels. At high concentrations, PA induces lipotoxicity through several mechanisms involving endoplasmic reticulum (ER) stress, mitochondrial dysfunction, inflammation and cell death. Nevertheless, there are endogenous strategies to mitigate PA-induced lipotoxicity through its unsaturation and elongation and its channeling and storage in lipid droplets (LDs), which plays a crucial role in sequestering oxidized lipids, thereby reducing oxidative damage to lipid membranes. While extended exposure to PA promotes mitochondrial reactive oxygen species (ROS) generation leading to cell damage, acute exposure of ß-cells to PA increases glucose-stimulated insulin secretion (GSIS), through the activation of free fatty acid receptors (FFARs). Subsequently, the activation of FFARs by exogenous agonists has been suggested as a potential therapeutic strategy to prevent PA-induced lipotoxicity in ß cells. Moreover, some saturated fatty acids, including oleic acid, can counteract the negative impact of PA on cellular health, suggesting a complex interaction between different dietary fats and cellular outcomes. Therefore, the challenge is to prevent the lipid peroxidation of dietary unsaturated fatty acids through the utilization of natural antioxidants. This complexity indicates the necessity for further research into the function of palmitic acid in diverse pathological conditions and to find the main therapeutic target against its lipotoxicity. The aim of this review is, therefore, to examine recent data regarding the mechanism underlying PA-induced lipotoxicity in order to identify strategies that can promote protection mechanisms against lipotoxicity, dysfunction and apoptosis in MetS and obesity.

Additive Manufacturing and Functionalization of Hollow Polypropylene Sorbents for Water Remediation.

As the demand for clean water intensifies, developing effective methods for removing pollutants from contaminated sources becomes increasingly crucial. This work establishes a method for additive manufacturing of functional polymer sorbents with hollow porous features, designed to enhance interactions with organic micropollutants. Specifically, core-shell filaments are used as the starting materials, which contain polypropylene (PP) as the shell and poly(acrylonitrile-co-butadiene-co-styrene)as the core, to fabricate 3-dimensional (3D) structures on-demand via material extrusion. After 3D printing, the cores of the printed roads are removed through solvent extraction, creating hollow structures that increase accessible surface area for adsorption. Subsequently, a sulfonation-induced crosslinking reaction installs sulfonic acid functionalities into the PP backbones, while enhancing their chemical stability. It is found that larger voids, and thinner polymer shells, enable improved structural retention during the sulfonation through limiting reaction-induced stresses. The hollow sulfonated PP sorbents exhibit a strong affinity againstcationic pollutants. Specifically, larger voids within these structures not only improve structural integrity but also result in accelerated adsorption kinetics by maximizing accessible surface area, thereby enhancing pollutant removal efficiency. This work provides a promising solution for advanced structured sorbent fabrication with hollow architectures, leading to more effective solutions for water contaminant removal in the future.

Sustainability and functionality of the combined organic acids and polyphosphates to inhibit calcium sulfate scaling

Sustainability and functionality of the combined organic acids and polyphosphates to inhibit calcium sulfate scaling

The immunological landscape of primary biliary cholangitis: Mechanisms and therapeutic prospects.

Primary Biliary Cholangitis (PBC) is a chronic cholestatic liver disease characterized by the progressive destruction of intrahepatic bile ducts, leading to fibrosis, and potentially cirrhosis. PBC has been considered a prototypical autoimmune condition, given the presence of specific autoantibodies and the immune response against well-defined mitochondrial autoantigens. Further evidence supports the interaction of immunogenetic and environmental factors in the aetiology of PBC. An immunological attack on biliary epithelial cells (BECs) with secondary failure of biliary transporters, e.g. the anion exchange protein 2 (AE2), is traditionally considered the primum movens. A recent hypothesis proposes a primary failure of BECs with the downregulation of AE2 secondary to epigenetic mechanisms (miR-506 overexpression) which then triggers the immunological storm. This highlights the secretory defect as culprit and sustaining factor in the pathogenesis of PBC with UDCA helping to restore this protective mechanism by promoting bicarbonate secretion and reducing bile acid toxicity. In this review we aim to provide the most recent evidence on the immunopathogenesis of PBC. We will analyse the immune function of the biliary epithelium, assessing the immunomodulatory functions of the bile acids and the evidence of the immunological roles of the secretory pathways targeted by the current treatments.

Roles and therapeutic opportunities of ω-3 long-chain polyunsaturated fatty acids in lung cancer.

Over the past decades, researchers have continuously investigated the potential functions of long-chain polyunsaturated fatty acids (LCPUFAs) in cancers, including lung cancer. The ω-3 LCPUFAs, primarily consisting of eicosapentaenoic acid and docosahexaenoic acid, were found to modify inflammatory tumor microenvironment, induce cancer cell apoptosis and autophagy, and suppress tumor development when administered alone or with other therapeutical strategies. Although the precise anti-tumor mechanism has not been elucidated yet, ω-3 LCPUFAs are often used in the nutritional treatment of patients with cancer due to their ability to significantly improve patient's nutritional status, increase the sensitivity of tumor cells to treatments, and alleviate cancer-related complications. Here we present the key roles of ω-3 LCPUFAs as dietary supplementations in lung cancer, comprehensively review the recent progress on the underlying mechanisms of cancer cell regulation by ω-3 LCPUFAs, and introduce the application of ω-3 LCPUFAs in the clinical management of lung cancer and its malignant complications.

A review of RNA nanoparticles for drug/gene/protein delivery in advanced therapies: Current state and future prospects.

Nanotechnology involves the utilization of materials with exceptional properties at the nanoscale. Over the past few years, nanotechnologies have demonstrated significant potential in improving human health, particularly in medical treatments. The self-assembly characteristic of RNA is a highly effective method for designing and constructing nanostructures using a combination of biological, chemical, and physical techniques from different fields. There is great potential for the application of RNA nanotechnology in therapeutics. This review explores various nano-based drug delivery systems and their unique features through the impressive progress of the RNA field and their significant therapeutic promises due to their unique performance in the COVID-19 pandemic. However, a significant hurdle in fully harnessing the power of RNA drugs lies in effectively delivering RNA to precise organs and tissues, a critical factor for achieving therapeutic effectiveness, minimizing side effects, and optimizing treatment outcomes. There have been many efforts to pursue targeting, but the clinical translation of RNA drugs has been hindered by the lack of clear guidelines and shared understanding. A comprehensive understanding of various principles is essential to develop vaccines using nucleic acids and nanomedicine successfully. These include mechanisms of immune responses, functions of nucleic acids, nanotechnology, and vaccinations. Regarding this matter, the aim of this review is to revisit the fundamental principles of the immune system's function, vaccination, nanotechnology, and drug delivery in relation to the creation and manufacturing of vaccines utilizing nanotechnology and nucleic acids. RNA drugs have demonstrated significant potential in treating a wide range of diseases in both clinical and preclinical research. One of the reasons is their capacity to regulate gene expression and manage protein production efficiently. Different methods, like modifying chemicals, connecting ligands, and utilizing nanotechnology, have been essential in enabling the effective use of RNA-based treatments in medical environments. The article reviews stimuli-responsive nanotechnologies for RNA delivery and their potential in RNA medicines. It emphasizes the notable benefits of these technologies in improving the effectiveness of RNA and targeting specific cells and organs. This review offers a comprehensive analysis of different RNA drugs and how they work to produce therapeutic benefits. Recent progress in using RNA-based drugs, especially mRNA treatments, has shown that targeted delivery methods work well in medical treatments.

Beyond metabolic messengers: Bile acids and TGR5 as pharmacotherapeutic intervention for psychiatric disorders.

Psychiatric disorders pose a significant global health challenge, exacerbated by the COVID-19 pandemic and insufficiently addressed by the current treatments. This review explores the emerging role of bile acids and the TGR5 receptor in the pathophysiology of psychiatric conditions, emphasizing their signaling within the gut-brain axis. We detail the synthesis and systemic functions of bile acids, their transformation by gut microbiota, and their impact across various neuropsychiatric disorders, including major depressive disorder, general anxiety disorder, schizophrenia, autism spectrum disorder, and bipolar disorder. The review highlights how dysbiosis and altered bile acid metabolism contribute to the development and exacerbation of these neuropsychiatric disorders through mechanisms involving inflammation, oxidative stress, and neurotransmitter dysregulation. Importantly, we detail both pharmacological and non-pharmacological interventions that modulate TGR5 signaling, offering potential breakthroughs in treatment strategies. These include dietary adjustments to enhance beneficial bile acids production and the use of specific TGR5 agonists that have shown promise in preclinical and clinical settings for their regulatory effects on critical pathways such as cAMP-PKA, NRF2-mediated antioxidant responses, and neuroinflammation. By integrating findings from the dynamics of gut microbiota, bile acids metabolism, and TGR5 receptor related signaling events, this review underscores cutting-edge therapeutic approaches poised to revolutionize the management and treatment of psychiatric disorders.

Reaction of Lactone-Containing Poly(benzofuran-co-arylacetic acid) with Diamines to Cross-Linked Products of Improved Thermal Conductivity.

The recently developed phenoplast-related polymer, poly(benzofuran-co-arylacetic acid), presents a versatile molecular structure containing lactone and carboxylic acid functionalities that offer significant flexibility in creating cured materials with tailored properties for diverse applications, wherein also the thermal conductivity is an important factor. This study analyses the possibility of forming amide moieties of poly(benzofuran-co-arylacetic acid) with diamines resulting in cross-linked products in order to control its thermal properties. The cross-linking process is achieved by utilizing three distinct diamines, 1,6-diaminohexane, p-xylylenediamine, and 4,7,10-trioxa-1,13-tridecanediamine, each possessing different degrees of polarity, flexibility, and reactivity. The resulting cross-linked zwitterionic poly(benzofuran-co-arylacetic acids) were structurally and morphologically characterized. By means of measuring the thermal conductivity and diffusivity of the materials, the possibility of adjusting the thermal properties of the cross-linked products by choosing appropriate linkers was determined. A case was developed where the thermal conductivity and diffusivity increased with temperature, a hardly found property in the cross-linking of polymers being important for many practical applications.

Nanosecond Laser Pulses Facilitating Efficient and Specific Cell Killing with Doxorubicin‐Loaded Gold Nanoparticles Targeted to the Folate Receptor

Nanoparticle‐based drug carrier systems with active targeting and a controlled release capacity are of considerable interest to bypass side effects of conventional chemotherapy. One appealing approach involves chemotherapeutic‐loaded photothermal nanoparticles, where laser irradiation can release the loaded anticancer drug while also inducing local cytotoxicity through photothermal effects. This study investigates the potential of using nanosecond‐pulsed laser light for efficient and specific killing of folate receptor (FR)‐overexpressing cancer cells in combination with FR‐targeted doxorubicin‐loaded gold nanoparticles (AuNPs). Nanosecond pulsed laser irradiation allows the induction of mechanical forces alongside thermal effects. The effect of nanoparticle concentrations and laser fluences on cytotoxicity is systematically tested, achieving near‐complete tumor cell killing under the most stringent conditions. FR targeting is confirmed using FR‐positive and ‐negative cell lines, showing that folic acid functionalization of AuNPs results in more favorable nanoparticle–cell interactions and more efficient photothermal effects. Additionally, doxorubicin could be efficiently released from the AuNPs and endosomal compartments upon laser irradiation, adding to the observed cytotoxicity. Cell killing was precisely confined to irradiated cells, leaving surrounding cells unharmed. Overall, the significant reduction of tumor cell viability following the proposed combination demonstrates this approach to be a promising step toward safer, more effective anticancer therapies.

Fisetin as a Blueprint for Senotherapeutic Agents - Elucidating Geroprotective and Senolytic Properties with Molecular Modeling.

Targeting senescent cells and the factors that accelerate this pathological state has recently emerged as a novel field in medicinal chemistry. As attention shifts to synthetic substances, studies on natural agents are often overlooked. In this paper, we present a detailed computational modeling study that encompasses quantum mechanics and molecular dynamics to elucidate the senotherapeutic activity of fisetin. The mitochondrial environment, serving as a proxy for senescence, received special attention. Throughout the study, fisetin's outstanding geroprotective properties-exhibiting significant potential against•OOH, O2•-, and•OH radicals, surpassing those of Trolox or ascorbate-were identified. Furthermore, fisetin demonstrated a high capacity to restore oxidatively damaged biomolecules to their pristine forms, thereby renewing the functionality of proteins and amino acids. The senolytic properties were examined in terms of Bcl-2 and Bcl-xL inhibition. The results indicated that fisetin not only binds effectively to these proteins but also, with appropriate modifications, may exhibit specific selectivity toward either target. This study highlights fisetin's remarkable activity in these areas and provides a molecular description of the underlying processes, paving the way for future research.

An intermolecular Lewis pair based on tin acid and phosphonium ylide base functions

Abstract The tin-containing Lewis acid group (C2F5)3Sn was combined with a phosphonium ylide as base function in one molecule: o-[(C2F5)3Sn]-C6H4(Ph)2PCMe2. It was prepared by reacting the ortho-lithiated triphenylphosphoniumdimethylmethylide (o-Li-C6H4)(Ph)2PCMe2 with the stannyl chloride (C2F5)3SnCl to afford o-[(C2F5)3Sn]-C6H4(Ph)2PCMe2 in 86 % yield. It forms a ring structure with a bond between tin and the ylidic carbon atom both in solution and in the solid state and can thus be considered as a hidden frustrated Lewis pair. The title compound is unreactive towards H2, CO2, CS2, PhNCO and decomposes in the presence of SO2 or NH3. However, it is active in the catalytic reduction of CO2 with pinacolborane, H–BPin. The title compound reacts slowly with H–BPin in an unselective reaction from which a reduction product with cleaved C2F5 group, the phosphonium stannate (II) o-[(C2F5)2Sn]-C6H4(Ph)2PCHMe2, could be obtained in small amounts.

Insights and progress on the biosynthesis, metabolism, and physiological functions of gamma-aminobutyric acid (GABA): a review.

GABA (γ-aminobutyric acid) is a non-protein amino acid that occurs naturally in the human brain, animals, plants and microorganisms. It is primarily produced by the irreversible action of glutamic acid decarboxylase (GAD) on the α-decarboxylation of L-glutamic acid. As a major neurotransmitter in the brain, GABA plays a crucial role in behavior, cognition, and the body's stress response. GABA is mainly synthesized through the GABA shunt and the polyamine degradation pathways. It works through three receptors (GABAA, GABAB, and GABAC), each exhibiting different pharmacological and physiological characteristics. GABA has a variety of physiological roles and applications. In plants, it regulates growth, development and stress responses. In mammals, it influences physiological functions such as nervous system regulation, blood pressure equilibrium, liver and kidneys enhancement, hormone secretion regulation, immunity enhancement, cancer prevention, as well as anti-aging effects. As a biologically active ingredient, GABA possesses unique physiological effects and medicinal value, leading to its widespread application and substantially increased market demand in the food and pharmaceutical industries. GABA is primarily produced through chemical synthesis, plant enrichment and microbial fermentation. In this review, we first make an overview of GABA, focusing on its synthesis, metabolism, GABA receptors and physiological functions. Next, we describe the industrial production methods of GABA. Finally, we discuss the development of ligands for the GABA receptor binding site, the prospects of GABA production and application, as well as its clinical trials in potential drugs or compounds targeting GABA for the treatment of epilepsy. The purpose of this review is to attract researchers from various fields to focus on GABA research, promote multidisciplinary communications and collaborations, break down disciplinary barriers, stimulate innovative research ideas and methods, and advance the development and application of GABA in medicine, agriculture, food and other fields.

Halogenated Cobalt Bis-Dicarbollide Strong Acids as Reusable Homogeneous Catalysts for Fatty Acid Esterification with Methanol or Ethanol.

The most commonly used homogeneous catalyst for fatty acid esterification is a corrosive sulphuric acid. However, this requires costly investment in non-corrosive equipment, presents a safety risk, is time consuming, and increases effluent generation. In this study, inorganic 3D heteroborane cluster strong acids are employed for the first time as homogeneous catalysts. Three novel isomeric tetrachlorido and tetrabromido derivatives of 3,3'-commo-bis[undecahydrido-closo-1,2-dicarba-3-cobaltadodecaborate](1-) [1-] were synthesised and fully characterised using a range of analytical techniques, including NMR, TLC, HPLC, MS, UV-Vis, melting point (MP), CHN analyses, and XRD. Ultimately, H3O[8,8'-Cl2-1-] was identified as the most efficient, reusable, and non-corrosive homogeneous catalyst for the esterification of four fatty acids. The reactions are conducted in an excess of alcohol at reflux. The effective absorption of water vapour provided by the molecular sieves maximises acid conversion. The hydrophobic dye Sudan black B was employed as an acid-base indicator to facilitate a comparison of the H0 acidity function of sulphuric acid and halogenated heteroboranoic acids when dissolved together in methanol. The 23Na NMR analysis demonstrated that the application of dry methanol resulted in the displacement of Na+ ions from zeolite, which subsequently exchanged the H3O+ ions of the acid. This process led to a gradual reduction in the efficiency of the catalysts, particularly with repeated use. The solution to this issue is to regenerate the catalyst on the ion exchanger following each reaction. In contrast to the published methods, our new approach meets 10 of 12 green chemistry principles.

Kopi, Trend Minuman Kekinian Dengan Banyak Manfaat Komponen Bioaktif

Coffee is a widely enjoyed beverage in Indonesia and around the world, holding a significant role as a key commodity in Indonesia's plantation sector. This beverage is popular not only for its distinctive flavor but also for its various health benefits. This article reviews several main bioactive components in coffee, including caffeine, chlorogenic acid, ferulic acid, and caffeic acid, as well as the potential health benefits of each. Caffeine is known as a stimulant that can enhance alertness, reduce drowsiness, and acts as a potential antioxidant. Chlorogenic acid functions as an anti-inflammatory, antihypertensive, antidiabetic, and anti-obesity agent, helping to reduce the risk of cardiovascular diseases. Ferulic acid has strong antioxidant effects and is used as a diabetes therapy due to its ability to reduce oxidative stress, while caffeic acid is known for its anticancer, antioxidant, and antibacterial activities, supporting the prevention of atherosclerosis and cardiovascular diseases. This article also discusses the mechanisms of action for each bioactive component within the body, particularly on the nervous system, lipid metabolism, and antioxidant activity. Through this review, coffee is understood not only as a refreshing beverage but also as a potential agent in the therapy and prevention of various chronic diseases.

Organic Molecule Functionalization Enables Selective Electrochemical Reduction of Dilute CO2 Feedstock

AbstractThe electrochemical conversion of low‐concentration CO2 feedstock to value‐added chemicals and fuels is a promising pathway for achieving direct valorization of waste gas streams. However, this is challenging due to significant competition from the hydrogen evolution reaction (HER) and lowered CO2 reduction (CO2R) kinetics as compared to systems that employ pure CO2. Here we show that terephthalic acid (TPA) functionalization can boost selectivity towards CO2R and suppress HER over a range of catalysts including Bi, Cu and Zn. For instance, TPA functionalized Bi attained a formate Faradaic efficiency (FEHCOO‐) of 96.3 % at 300 mA cm−2 with pure CO2 feedstock. Density functional theory simulations indicate that this is because TPA functionalization modulates the binding energies of the key reaction intermediates *OCHO and *H. With low‐concentration feedstock (15 % CO2) at 100 mA cm−2, we achieved a high FEHCOO‐ of 85.8 %, which was double that of an unmodified Bi catalyst. Using an electrolyzer with a porous solid electrolyte layer, we successfully showcase 30 h of continuous high‐purity formic acid production with a 5 % CO2 feed. Taken together, our findings demonstrate that molecular tuning of a catalyst can be an effective strategy for enabling selective CO2R using low‐concentration feedstock.