Reaction Of Acid Research Articles

Interface-Strengthened Ru-Based Electrocatalyst for High-Efficiency Proton Exchange Membrane Water Electrolysis at Industrial-Level Current Density

Developing an OER electrocatalyst that balances high performance with low cost is crucial for widely adopting PEM water electrolyzers. Ru-based catalysts are gaining attention for their cost-effectiveness and high activity, positioning them as promising alternatives to Ir-based catalysts. However, Ru-based catalysts can be prone to oxidation at high potentials, compromising their durability. In this study, we utilize a simple synthesis method to synthesize a SnO2, Nb2O5, and RuO2 composite catalyst (SnO2/Nb2O5@RuO2) with multiple interfaces and abundant oxygen vacancies. The large surface area and numerous active sites of the SnO2/Nb2O5@RuO2 catalyst lead to outstanding acidic oxygen evolution reaction (OER) performance, achieving current densities of 10, 50, and 200 mA cm−2 at ultralow overpotentials of 287, 359, and 534 mV, respectively, significantly surpassing commercial IrO2. Moreover, incorporating Nb2O5 into the SnO2/Nb2O5@RuO2 alters the electronic structure at the interfaces and generates a high density of oxygen vacancies, markedly enhancing durability. Consequently, the membrane electrode composed of SnO2/Nb2O5@RuO2 and commercial Pt/C demonstrated stable operation in the PEM cell for 25 days at an industrial current density of 1 A cm−2. This research presents a convenient approach for developing a highly efficient and durable Ru-based electrocatalyst, underscoring its potential for proton exchange membrane water electrolysis.

NiIr nanowireassembles as an efficient electrocatalyst towards oxygen evolution reaction in both acid and alkaline media.

Oxygen evolution reaction (OER) is the rate-limiting step in water electrolysis due to its sluggish kinetic, and it is challenging to develop an OER catalyst that could work efficiently in both acid and alkaline environment. Herein, NiIr nanowire assembles (NAs) with unique nanoflower morphology were prepared by a facile hydrothermal method. As a result, the NiIr NAs exhibited superior OER activity in both acid and alkaline media. Specifically, in 0.1 M HClO4, NiIr NAs presented a superior electrocatalytic performance with a low overpotential of merely 242 mV at 10 mA cm-2 and a Tafel slope of only 58.1 mV dec-1, surpassing that of commercial IrO2 and pure Ir NAs. And it achieved a significantly higher mass activity of 148.40 A/g at -1.5 V versus RHE. In 1.0 M KOH, NiIr NAs has an overpotential of 291 mV at 10 mA cm-2 and a Tafel slope of 42.1 mV dec-1. Such remarkable activity makes the NiIr NAs among the best of recently reported representative Ir-based OER electrocatalysts. Density functional theory (DFT) calculations confirmed alloying effect promotes surface bonding of NiIr with oxygen-containing reactants, resulting in excellent catalytic properties.

Assessment of spatial variability of agrochemical properties of agro-gray soil when planning a feld experiment with mineral fertilizers

The purpose of the work is to investigate the statistical parameters and patterns of variability of agrochemical indicators of agro–gray soil, elements of the structure of the spring wheat crop within the plots of the experimental field. Experimental data were obtained on the basis of observations conducted on agricultural landscapes Sukhobuzimskoye land areas in the Krasnoyarsk forest-steppe of the Krasnoyarsk geomorphological district, located borders the Chulym-Yenisei denudation plateau in the southwestern outskirts of Central Siberia. The results of the intra-field heterogeneity of the agrochemical properties of the agro-gray soil and the elements of the structure of the spring wheat crop on the site intended for field experiment are presented. The key statistical and geostatistical values of the intrafield heterogeneity are determined. The statistics of agrochemical indicators and the results of crop data from the plots intended for the placement of repetitions are analyzed. The materials of the agrochemical survey of the agro-gray soil revealed a low humus content. The level of spatial variation of the indicator corresponded to the average. The scope of variation is represented by values covering only one gradation of the evaluation scale. The entire studied area was characterized by a slightly acidic reaction of the medium according to the average pH values. Its variation in the 0-20 cm soil layer indicated uniformity of distribution in space. The level of variability of agrochemical indicators decreased in the following series: yield (40 %) > humus (19 %) > P2O5 (13 %) > K2O (10 %) > pH2O (4 %). According to the generalization of geostatistical information, the analyzed site is classified as unaligned in terms of soil fertility. In general, the soil fertility of the studied area had a significant variation, which determined the choice of elements of the field experience methodology. When laying out field experience, it is necessary to choose the appropriate elements of the methodology: a randomized method of placing repetitions, rectangular or elongated forms of plots.

Formation of Nitrosamines from the Heterogeneous Reaction of Nitrous Acid and Organic Amines in Indoor Environments.

Carcinogenic nitrosamines have been widely studied due to their risk to human health. However, the universality and evolutionary processes of their generation, particularly concerning their secondary sources, remain unclear at present. We demonstrated through laboratory flow tube experiments that corresponding nitrosamines were generated from heterogeneous reactions of nitrous acid (HONO) with five structurally diverse amines commonly found indoors, including diphenylamine (DPhA), dibenzylamine (DBzA), dioctylamine (DOtA), N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine (6PPD), and N-phenyl-1-naphthylamine (PANA). The heterogeneous reaction rate constants of DBzA and DOtA with HONO (∼70 ppb) were 1.21 × 10-3 and 2.13 × 10-3 min-1 at 30% relative humidity (RH), resulting in a lifetime of 13.8 and 7.8 h. As compared to higher RH (∼80%), more nitrosamines were produced from the reaction of HONO with surface-sorbed DBzA, DOtA, 6PPD, and PANA at lower RH (30%), with product yields ranging from <0.1% to 0.5%. Furthermore, we observed the formation of nitroso-6PPDs and nitro-6PPDs during room air exposure of 6PPD in a genuine indoor environment, in addition to various other transformation products indicative of reactions of 6PPD with HONO, NOx, and ozone indoors. This study confirmed the universality of the heterogeneous reaction of surface-sorbed amine with HONO as a source of nitrosamines indoors.

Effect of green tea or black tea extract on lipid and protein oxidation in Cantonese sausage.

Natural polyphenols offer a safer alternative to synthetic antioxidants in meat products. This study investigated the efficacy of green tea and black tea extracts as natural antioxidants in Cantonese sausages to inhibit lipid and protein oxidation. Sausages were prepared with the addition of different concentrations - 100, 300, and 600 mg kg-1 total polyphenols (TP) - of green tea or black tea extract. Oxidation of the sausages was assessed through thiobarbituric acid reactants, carbonyl content, and thiol content, whereas consumer acceptability was evaluated based on texture, color, and sensory analysis. The tea extracts inhibited malondialdehyde production and reduced the thiobarbituric acid reactive substance value from 23.72 mmol MDA g-1 to less than 1.94 mmol MDA g-1. However, the addition of tea extracts decreased the thiol content and caused the loss of myosin heavy chain and actin bonds in sodium dodecyl sulfate polyacrylamide gel electrophoresis. Although the addition of tea extracts increased the redness and hardness of the sausage, no significant difference in consumer acceptance between the control and treatment groups was observed in the sensory analysis. The tea extract inhibited the oxidation of lipids in Cantonese sausage. There was no negative effect on the sensory characteristics of sausages. The use of tea extracts as natural antioxidants in Cantonese sausage is therefore feasible. © 2024 Society of Chemical Industry.

Unveiling the Structure and Dissociation of Interfacial Water on RuO2 for Efficient Acidic Oxygen Evolution Reaction.

Understanding the structure and dynamic process of interfacial water molecules at the catalyst-electrolyte interface on acidic oxygen evolution reaction (OER) kinetics is highly desirable for the development of proton exchange membrane water electrolyzers. Herein, we construct a series of p-block metallic elements (Ga, In, Sn) doped RuO2 catalysts with manipulated electronic structure and Ru-O covalency to investigate the effect of electrochemical interfacial engineering on the improvement of acidic OER activity. Associated with operando attenuated total reflectance surface-enhanced infrared absorption spectroscopy measurements and theoretical analysis, we uncover the free-H2O enriched local environment and dynamic evolution from 4-coordinated hydrogen-bonded water and 2-coordinated hydrogen-bonded water to free-H2O on the surface of Ga-RuO2, are responsible for the optimized connectivity of hydrogen bonding network in the electrical double layer by promoting solvent reorganization. In addition, the structurally ordered interfacial water molecules facilitate high-efficiency proton-coupled electron transfer across the interface, leading to reduced energy barrier of the follow-up dissociation process and enhanced acidic OER performance. This work highlights the key role of structure and dynamic process of interfacial water for acidic OER, and demonstrates the electrochemical interfacial engineering as an efficient strategy to design high-performance electrocatalysts.

Tannic Acid Film Based on One-Dimensional Supramolecular Self-Assembly for Electrical Conductivity and Oil-Water Separation.

Tannic acid is widely regarded as one of the most promising natural polyphenolic compounds. However, current research predominantly focuses on the utilization of its phenolic hydroxyl groups, with limited exploration of the functional potential of its aromatic structure. Herein, one-dimensional nanofibers based on supramolecular self-assembly were successfully prepared through the simple alkylation reaction of tannic acid and the π-π stacking of aromatic structures. These fibers, with lengths reaching tens of micrometers and an average height of 10 nm, were clearly observed using SEM and AFM. A film with excellent electrical conductivity (σ = 37.9 μS/cm) was fabricated by vacuum filtering the organic suspension of these fibers, which was 100-fold higher than that of the TA film. Additionally, the hydrophobic and lipophilic properties of Bn-TA were further investigated through oil-water separation experiments, where the Bn-TA membrane displayed excellent separation efficiency and durability, maintaining stable performance over multiple cycles. This strategy presents opportunities for the high-value utilization of tannic acid.

Unveiling the Structure and Dissociation of Interfacial Water on RuO2 for Efficient Acidic Oxygen Evolution Reaction

Understanding the structure and dynamic process of interfacial water molecules at the catalyst‐electrolyte interface on acidic oxygen evolution reaction (OER) kinetics is highly desirable for the development of proton exchange membrane water electrolyzers. Herein, we construct a series of p‐block metallic elements (Ga, In, Sn) doped RuO2 catalysts with manipulated electronic structure and Ru‐O covalency to investigate the effect of electrochemical interfacial engineering on the improvement of acidic OER activity. Associated with operando attenuated total reflectance surface‐enhanced infrared absorption spectroscopy measurements and theoretical analysis, we uncover the free‐H2O enriched local environment and dynamic evolution from 4‐coordinated hydrogen‐bonded water and 2‐coordinated hydrogen‐bonded water to free‐H2O on the surface of Ga‐RuO2, are responsible for the optimized connectivity of hydrogen bonding network in the electrical double layer by promoting solvent reorganization. In addition, the structurally ordered interfacial water molecules facilitate high‐efficiency proton‐coupled electron transfer across the interface, leading to reduced energy barrier of the follow‐up dissociation process and enhanced acidic OER performance. This work highlights the key role of structure and dynamic process of interfacial water for acidic OER, and demonstrates the electrochemical interfacial engineering as an efficient strategy to design high‐performance electrocatalysts.

TCFH-NMI Ketone Synthesis Inspired by Nucleophilicity Scales.

N,N,N',N'-Tetramethylchloroformamidinium hexafluorophosphate (TCFH) and N-methylimidazole (NMI) enable the facile and practical reaction of carboxylic acids with amines, alcohols, and thiols to form amides, esters, and thioesters. To develop a mild synthesis of ketones with TCFH-NMI directly from carboxylic acids at room temperature, the Mayr nucleophilicity scale was used to compare the N values of competent nucleophiles to potential carbon-centered nucleophiles, identifying pyrroles and indoles as successful substrates when N ≥ 10.

Pokrywa glebowa miasta Lublina (wschodnia Polska)

Lublin is a voivodeship city located in the Lublin Upland (Eastern Poland). The study aimed to present the spatial differentiation of soils of the city of Lublin and some of their properties. The knowledge of soil cover is very important for spatial planning and for protection and proper use of soil resources of each city. The environmental-genetic map of Lublin’s soils included in this work was made on the basis of soil-agricultural map in the scale 1:25 000 of Lublin and the soil-habitat map of the Świdnik Forest District. The soil units distinguished on the map were classified according to the Systematics of Soils of Poland (2019) and the international soil classification (World Reference Base for Soil Resources, WRB). The spatial variability of Lublin’s soils is determined by the occurrence of different parent rocks, relief, water relations, vegetation cover and human activities. The main soil units occurring within the city of Lublin include: brown soils (WRB: Eutric/Dystric Cambisols), rusty soils (Brunic Arenosols), podzolic soils (Albic Podzols), clay-illuvial soils/lessive soils (WRB: Albic/Haplic Luvisols), black earths (WRB: Gleyic Phaeozems), chernozemic rendzinas (WRB: Rendzic Phaeozems) and brown rendzinas (WRB: Calcaric Cambisols), chernozemic/black alluvial soils (WRB: Fluvic Phaeozems) and ordinary alluvial soils (WRB: Dystric/Eutric Fluvisols), peat soils (WRB: Hemic/Sapric Histosols) and murshic soils (WRB: Murshic Histosols), and technogenic soils (WRB: Urbic/Spolic/Ekranic Technosols). The grain size composition of Lublin’s soils is quite diverse, with the most common being silts, loams and sands with varying proportions of skeletal parts. The reaction of the Lublin soils studied also varies. Very acidic and acidic reaction is present mainly in podzolic and rusty soils and typical acid brown soils. In contrast, proper brown soils are slightly acidic to neutral in the upper genetic horizons. Lessive soils also have an acid reaction in the upper genetic horizons. Fluvisols have a slightly acidic to alkaline reaction, and black earths have a neutral to alkaline reaction. The alkaline reaction is found in rendzinas and technogenic soils, in which significant amounts of calcium carbonate are present. Soil organic matter is mainly accumulated in organic soils (peat and muck soils), as well as in the surface organic horizons (O) of forest soils. In the mineral soils of Lublin, the highest content of organic carbon (C-org) was found in such soils as black earths, chernozemic rendzinas, chernozemic alluvial soils and in some technogenic soils. The usable quality of Lublin’s soils is high. There is a phenomenon of management of land with high bonitation classes for non-agricultural purposes, despite the high fees for excluding such land from agricultural production.

Cu3(HITP)2 with peroxidase- and ascorbic acid oxidase-like catalytic activity for fluorescence/chemiluminescence sensing of ascorbic acid

Nanomaterials with intrinsic enzyme mimicking activity have achieved widespread application. However, developing novel nanomaterials with multienzyme mimicry activity remains challenging. Herein, Cu3(HITP)2 (HITP = 2,3,6,7,10,11-hexaiminotriphenylene) with ascorbic acid oxidase (AAO)- and peroxidase (POD)-like activity are successfully synthesized. Cu3(HITP)2 exhibits excellent AAO-like activity and can specifically catalyze the oxidation reaction of ascorbic acid (AA). Dehydroascorbic acid (DHAA) obtained from the oxidation of AA is allowed to react with nonfluorescent o-phenylenediamine (OPD) to form 3-(1,2-dihydrox-yethyl) furo[3,4-b]quinoxaline-1-one (DFQ) with strong fluorescence emission. Moreover, Cu3(HITP)2 is able to catalyze the chemiluminescence (CL) reaction of ABEI-H2O2 to generate a strong and glow-type emission based on its POD activity. Inspired by the multienzyme mimicry activity of Cu3(HITP)2, the simple and sensitive fluorescence and chemiluminescence sensing platforms are successfully constructed and applied for the detection of AA. The sensors show high sensitivity and excellent selectivity. We believe that this multienzyme mimicry activity nanomaterial not only can be used to construct the multiple-mode biosensing platform, but also enables the extensive applications in the fields of biomedicine, energy, and environment.

A "lysosomal bomb" constructed based on amorphous calcium carbonate to induce tumor apoptosis by amplified sonodynamic therapy

The acidic nature of malignant tumors leads to increased drug sequestration and the evasion of apoptotic damage, which is further exacerbated by abnormal lysosomes in tumor cells. In this study, a "lysosomal bomb" will be constructed using a type of acid-neutralized amorphous calcium carbonate (ACC) to encapsulate the sonosensitizer protoporphyrin IX (PpIX), and then coated with homologous tumor cell membranes to increase water solubility and homologous targeting. The PpIX-ACC@CMs designed in this paper are popcorn-like structures, which can not only neutralize the tumor's acidic microenvironment to balance the pH value and release excess Ca2+, but also cause lysosomal dysfunction and achieve drug lysosomal escape to increase drug accumulation. Additionally, the CO2 gas nucleus produced by the acid reaction of ACC can increase the ultrasonic cavitation effect to amplify the sonodynamic therapy (SDT) effect. In vitro and in vivo experiments demonstrated that PpIX-ACC@CMs, serving as a "lysosomal bomb," successfully localized to lysosomes of tumor cells and exhibited lysosomal escape ability through its acid reaction ability, achieving excellent SDT efficacy under ultrasound stimulation. Furthermore, exogenous Ca2+ overload also increased the likelihood of tumor calcification, which could contribute to in vivo tumor inhibition and facilitate CT medical imaging to monitor treatment efficacy.

Recent Research on Iridium-Based Electrocatalysts for Acidic Oxygen Evolution Reaction from the Origin of Reaction Mechanism.

As the anode reaction of proton exchange membrane water electrolysis (PEMWE), the acidic oxygen evolution reaction (OER) is one of the main obstacles to the practical application of PEMWE due to its sluggish four-electron transfer process. The development of high-performance acidic OER electrocatalysts has become the key to improving the reaction kinetics. To date, although various excellent acidic OER electrocatalysts have been widely researched, Ir-based nanomaterials are still state-of-the-art electrocatalysts. Hence, a comprehensive and in-depth understanding of the reaction mechanism of Ir-based electrocatalysts is crucial for the precise optimization of catalytic performance. In this review, the origin and nature of the conventional adsorbate evolution mechanism (AEM) and the derived volcanic relationship on Ir-based electrocatalysts for acidic OER processes are summarized and some optimization strategies for Ir-based electrocatalysts based on the AEM are introduced. To further investigate the development strategy of high-performance Ir-based electrocatalysts, several unconventional OER mechanisms including dual-site mechanism and lattice oxygen mediated mechanism, and their applications are introduced in detail. Thereafter, the active species on Ir-based electrocatalysts at acidic OER are summarized and classified into surface Ir species and O species. Finally, the future development direction and prospect of Ir-based electrocatalysts for acidic OER are put forward.

Synthesis, Material Properties, and Organocatalytic Performance of Hypervalent Iodine(III)-Oxidants in Core–Shell-Structured Magnetic Nanoparticles

Magnetic nanoparticles (MNPs) based on magnetite (Fe3O4) are attractive catalyst supports due to their high surface area, easy preparation, and facile separation, but they lack stability in acidic reaction media. The search for MNPs stable in oxidative acidic reaction media is a necessity if one wants to combine the advantages of MNPs as catalyst supports with those of iodine(III) reagents being environmentally benign oxidizers. In this work, immobilized iodophenyl organocatalysts on magnetite support (IMNPs) were obtained by crossed-linking polymerization of 4-iodostyrene with 1,4-divinylbenzene in the presence of MNPs. The obtained IMNPs were characterized by TGA, IR, SEM, STEM, and HAADF to gain information on catalyst morphology, average particle size (80–100 nm), and their core–shell structure. IMNP-catalysts tested in (i) the α-tosyloxylation of propiophenone 1 with meta-chloroperbenzoic acid (m-CPBA) and (ii) in the oxidation of 9,10-dimethoxyanthracene 3 with Oxone® as the side-oxidant showed a similar performance as reactions using stoichiometric amounts of iodophenyl. The developed IMNPs withstand strong acidic conditions and serve as reusable organocatalysts. They are recyclable up to four times for repeated organocatalytic oxidations with rates of recovery of 80–92%. This is the first example of a—(4-iodophenyl)polystyrene shell—magnetite core-structured organocatalyst withstanding strong acidic reaction conditions.

A convenient bottom up route to covalently anchor Pd(II)-PEPPSI on layered zirconium(IV) phosphonate: Efficient catalyst for Suzuki-Miyaura cross coupling of aryl chlorides

A rational and bottom-up route for assembling layered Zr(IV) phosphonate framework decorated with covalently anchored N-heterocyclic carbene NHC-Pd(II) fragment has been developed. Reaction of phosphonic acid functionalized Pd(II)-NHC precursor complex with ZrOCl2·8H2O provides easy access to a layered material with covalently anchored catalytically active Pd(II)-NHC sites. The Pd(II)-NHC functionalized Zr(IV) phosphonate showed enhanced catalytic activity in Suzuki-Miyaura cross coupling reaction of both aryl bromides and chlorides with aryl boronic acid, as compared to their homogeneous counterparts. The Zr(IV) phosphonate framework imparts remarkable robustness to the Pd(II)-NHC catalyst and allowed recycling of the catalyst up to nine catalytic cycles without any major loss of catalytic activity.

A novel bio-based ferric flame retardant effectively improving the flame retardancy and mechanical properties of polylactic acid

PTDF is prepared by a convenient ionic reaction of phytic acid, terephthalic dihydrazide and iron salts in water. PTDF has high phosphorus and nitrogen content and good thermal stability, which can effectively improve the flame retardancy of PLA. PTFE is an anti-drip agent and is often used to improve the flame retardancy of PLA together with flame retardants. The addition of 4 wt% PTDF and 0.1 wt% PTFE made PLA reach V-0 flame retardant grade from non-flame retardant, and the oxygen index increased from 19.5 % to 24.5 %. With the increase of PTDF content, the performance of PLA improved significantly. The peak heat release rate (PHRR) and THR of PLA/6PTDF composites decrease by 27.4 % and 16.2 %, respectively, and the flame retardant index FRI increase by 232 %, showing excellent flame retardant efficiency. 6 wt% PTDF can increase the crystallinity of PLA by 25.9 %, tensile strength, maximum force required for impact fracture and notch impact strength by 12 %, 37 % and 129 %, respectively, and effectively improve the mechanical properties and toughness of the composite. The bio-based flame-retardant PLA/PTDF composites reported in this paper can be applied to office equipment.

Synthesis and Characterization of s-Triazine Cored Schiff Base Containing β-lactam and Its [M(Salen/Saloph)] (M= Cr3+ and Fe3+) Capped Complexes

This study consists of a tripodal 6-iminopenicylanic acid ligand synthesized based on the s-triazine group and its four trinuclear complexes. For this purpose, 2,4,6-tri(p-formylphenoxy)-1,3,5-triazine (III) (TRIPOD) was obtained from the reaction of 2,4,6-trichloro-1,3,5-triazine and 4-hydroxybenzaldehyde. Then, tripodal target ligand (V) was obtained from the reaction of TRIPOD and 6-aminopenicylanic acid. Finally, tripodal trinuclear (ML) capped target complexes were obtained from the reactions of the initial complexes [(ML)2O] (M= Cr3+ or Fe3+, L= Salen or Saloph) with the target ligand in methanol media. The structures of all obtained ligands were elucidated using 1H NMR, FT-IR, and elemental analysis methods. The structures of the complexes were characterized using FT-IR, magnetic susceptibility, ICP-OES, and TGA methods.

Indium‐Catalyzed Direct Amidation Reaction of Carboxylic Acids and In Silico Study for Screening the Activity of Potential Therapeutics of the Synthesized Products

AbstractAmide bonds are ubiquitous and valuable motifs in synthetic chemistry, found in a wide range of applications such as the backbone of proteins and pharmaceutical agents. Thus, environmentally friendly and selective methods for synthesizing amide bonds are important. Herein, we report a simple, efficient, and rapid route to access a range of functionalized amides from non‐activated carboxylic acids and amines using indium (III) trifluoromethanesulfonate as an efficient catalyst. A wide range of carboxylic acids – including aliphatic, aromatic, heterocyclic, and dicarbonyl acids – participate smoothly in these reactions, generating structurally diverse amides in moderate to good yields (up to 91 % in 24 examples). The reactions are conducted in dry tetrahydrofuran (THF) under reflux conditions. Furthermore, this amidation strategy provides a method for addressing challenging molecules, such as protected amino acids, to produce biocompatible products. These products can then be used as substrates for various organic transformations, including C−H functionalization reactions. We also demonstrate the synthetic utility of our protocol through the synthesis of essential substrates in organic and medicinal chemistry by reacting N‐protected carboxylic acids with 8‐aminoquinoline to produce a series of biologically valuable compounds. Five of these products, named 4 f, 4p, 9a, 9c, and 9d, have been biologically evaluated through an in‐silico study. The interaction of these compounds with receptor protein 8DQT was examined to assess their potential as drug candidates for hypertension treatment. Effective binding was detected between these compounds and the receptor. Data from molecular docking studies show that compounds 4d and 4 m are the most active, with binding scores of −8.8 and −8.6 kcal/mol, respectively. However, compound 4 m exhibited a stronger binding affinity than compound 4d over the course of dynamic simulation. Our ADMET study suggests that all five compounds are highly safe in the body. Based on the BOILED‐Egg model study, good absorption is suggested for all the molecules, and they can cross the blood‐brain barrier.

Simple and efficient enrichment and separation of glycoprotein by teamed boronate affinity magnetic carbon nanospheres

Protein glycosylation is a key regulatory mechanism that controls many physiological and pathological processes. Analyses of glycoproteins in biological samples require challenging enrichment steps in light of sample complexity and low glycoprotein abundance. Here, in order to develop an efficient method to enrich glycoproteins, a magnetic carbon nanospheres (MCs) rich in amino group and polyboric acid sites was designed and prepared. The teamed boronate affinity was formed by the self-assembled of amino group and boric acid, which can specifically capture glycoprotein containing cis-diol under neutral conditions. Firstly, a simple green hydrothermal method led to the production of a carbon nanospheres matrix with abundant surface hydroxyl and carboxyl moieties. Then, MCs were synthesized by solvothermal method. Subsequently, the MCs were modified with polyethyleneimine and boric acid in turn to obtain the proposed composite. The hydrophilicity of amino group and its hydrogen bond with glycoprotein, as well as the cyclization reaction of boric acid with cis-1,2-diol, are utilized to specifically bind to glycoprotein. The prepared magnetic nanospheres exhibited binding to glycoproteins with rapid kinetics and strong affinity. Adsorption equilibrium was reached within 40 min, and the adsorption capacities for the glycoproteins ovalbumin, transferrin and horseradish peroxidase were found to be 493, 346 and 326 mg/g, respectively, while the adsorption capacities for the non-glycoproteins bovine serum protein and lysozyme were 60 and 30 mg/g, respectively. This novel nanoparticle provides a simple and efficient method for the enrichment and separation of glycoproteins from biological samples.

Iron‐Catalyzed, Visible‐Light‐Mediated Decarboxylative Cyclization Reactions: A Viable Approach to 2,3‐Dihydrobenzofuran Derivatives

AbstractThis study reports a visible‐light‐induced photoredox decarboxylative cyclization reaction of enone acids via iron photocatalysis. The protocol provides a facile entry to structurally valuable highly functionalized 2,3‐dihydrobenzofuran scaffolds in good to excellent yields. This method features cheap iron photocatalyst, excellent functional group tolerance, wide substrate scope, and environmentally friendly features.