Compounds

Herein, we present hybrid crown ether ligands with siloxane and ethylene oxide units and their coordination with the cations Li⁺, Na⁺, Mg²⁺ and Ca²⁺. The compounds prepared are (SiMe₂O)₂(C₂H₄O)₃ (1, TrEGDS = Triethylenglycoldisiloxane) and (SiMe₂O)₂(C₂H₄O)₄ (2, TeEGDS = Tetraethylenglycoldisiloxane)), as well as the metal complexes [Li(TrEGDS][GaI₄] (3), [Na(TeEGDS)][GaI₄] (4), [Mg(TrEGDS)][GaI₄]₂ (5) and [Ca(TeEGDS)][GaI₄]₂ (6). Single-crystal X-ray diffraction was used to study the prepared complexes and coordination modes in the solid state. Full article

Alumina is a well-known catalyst and catalyst support. The electrochemical properties of alumina have recently gained attention. The electrochemical response of alumina greatly depends on the type and number of surface groups present in different alumina types. The surfaces of two types of alumina, anhydrous (A) and trihydrate (T) alumina, were modified by copper through an ion-exchange procedure. The samples were characterized by diffuse reflectance UV–Vis spectroscopy. The obtained samples were used as modifiers of carbon paste electrodes. The electrochemical characterization of the samples was performed using cyclic voltammetry and two redox probes. The electrochemical behavior of samples was investigated in the alkaline and neutral media. The electroanalytical performance of the synthesized composites was tested on glutamate and hydrogen peroxide by linear sweep voltammetry. The functionalization of alumina with copper by ion exchange offered a fast and cost-effective procedure for obtaining a composite with enhanced electrochemical properties for sensing biologically important analytes. Full article

Secondary metabolites such as flavonoids bring a range of biological properties to natural products, making them potential candidates for the pharmaceutical industry. Piptadenia stipulacea (Benth.) Ducke is well known in Brazil as Jurema Branca, and yet few studies have investigated its biological and phytochemical properties. This study aimed to characterize and evaluate the biological properties of ethanolic extract obtained from the bark of Jurema Branca. Characterization was performed by qualitative phytochemistry, HPLC, and mass spectroscopy. The antibacterial properties were investigated by microdilution method, cytotoxicity by MTT method, biocompatibility testing with human erythrocytes was performed, and antioxidant properties were investigated using DPPH and ABTS radical scavenging. The phytochemical tests demonstrated that rhamnetin and luteolin were the main constituents of the extract. This is the first report of these compounds in this species. The extract presented activity against Staphylococcus aureus (MIC = 500 µg/mL) and demonstrated activity against human colorectal adenocarcinoma (HCT-116), prostate adenocarcinoma (PC-3), and acute myeloid leukemia (HL-60) cell lines with IC₅₀ of 37.96, 37.6, and 27.82 µg/mL, respectively, for this Piptadenia genus. Additionally, the extract presented excellent biocompatibility and antioxidant activity (IC₅₀ = 956.7 and 147.2 µg/mL in DPPH and ABTS methods, respectively). These results are novel for the Piptadenia genus and pave the way for further evaluations regarding the biological importance of this species. Full article

FOSs are short-chain fructose-based oligosaccharides with notable functional and health benefits. Naturally present in various fruits and vegetables, FOSs are primarily produced enzymatically or microbially from sucrose or long-chain fructans, namely, inulin. Enzymes such as fructosyltransferase, β-fructofuranosidase, and endoinulinase are typically involved in its production. The chemical structure of FOSs consists of an assembly of fructose residues combined with a glucose unit. The increasing consumer demand for healthy foods has driven the widespread use of FOSs in the functional food industry. Thus, FOSs have been incorporated into dairy products, beverages, snacks, and pet foods. Beyond food and feed applications, FOSs serve as a low-calorie sweetener for and are used in dietary supplements and pharmaceuticals. As a prebiotic, they enhance gut health by promoting the growth of beneficial bacteria, aid digestion, improve mineral absorption, and help regulate cholesterol and triglyceride levels. Generally recognized as safe (GRAS) and approved by global regulatory agencies, FOSs are a valuable ingredient for both food and health applications. This review provides an updated perspective on the natural sources and occurrence of FOSs, their structures, and physicochemical and physiological features, with some focus on and a critical assessment of their potential health benefits. Moreover, FOS production methods are concisely addressed, and forthcoming developments involving FOSs are suggested. Full article

Using DFT+DMFT, we show the importance of spin-orbit coupling together with multi-orbital interactions in prescribing the reconstructed electronic state of the cubic CsPbI₃ crystal. Considering realistic Coulomb parameter values and Pb-spin-orbit interaction, we uncover relevant key features in the one-particle spectral functions for the Pb-6p and I-5p orbitals of semiconducting CsPbI₃ bulk crystal and the role played by p and n doping relevant for band-selective metallicity and current-voltage characteristics. The implication of our study for cubic CsPbI₃ is expected to be an important step to understanding the electronic structure of pure and doped broadband solar cell-based memristor materials for neuromorphic computing. Full article

The cocrystallization technique has been widely applied in the fields of energetic materials (EMs) to settle the inherent trade-off between high energy and low sensitivity in current high-energy molecules. Despite its widespread application, the mechanistic understanding of cocrystals growing from solutions remains largely underexplored. This paper presents a mechanistic model grounded in the spiral growth mechanism to predict the crystal morphologies of 2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane (CL-20) and 7H-trifurazano [3,4-b:3′,4′-f:3″,4″-d]azepine (TFAZ) cocrystals. In this model, it was assumed that CL-20 and TFAZ molecules incorporated into the crystal lattice simultaneously from solution as preformed growth units. The binding energies between the CL-20 molecule and TFAZ molecule were calculated to determine the most potential growth units. The predicted morphologies closely align with the experimental determinations supporting the model’s validity. Furthermore, the study found that the crystal habits were significantly influenced by the choice of solvents, due to variations in interfacial energetics affecting the growth process. Full article

The depletion of fossil fuels and environmental concerns have driven the development of sustainable materials, including bio-based and biodegradable plastics, as alternatives to conventional plastics. Although these plastics aid in waste management and climate change mitigation, their vulnerability to oxidative degradation impacts their longevity, durability, and performance. Natural antioxidants such as tocopherols, flavonoids, and tannins, extracted from plants or agri-food waste, present a sustainable alternative to synthetic stabilizers by enhancing the oxidative thermal stability of polymers like poly(lactic acid) (PLA), poly(butylene succinate) (PBS), poly(butylene succinate-adipate) (PBSA), poly(butylene adipate-co-terephthalate) (PBAT), poly(hydroxyalkanoate) (PHA), and starch-based materials. This review highlights recent advances in bio-based plastics stabilized with natural antioxidants, their mechanisms of action, and their role in improving material properties for applications like packaging. Additionally, it explores their impact on recycling processes, advancements in composite production techniques, and future research directions. Bioplastics can achieve enhanced performance, reduce waste, and support a circular economy by incorporating natural antioxidants. Full article

The genus Hypericum (Hypericaceae), comprising approximately 500 taxa classified into 22 sections, has remained largely unexplored in terms of its chemical composition, with existing studies on a limited number of species revealing significant chemical polymorphism. This study investigates the volatile profiles of four Hypericum species (H. rumeliacum subsp. apollinis, H. vesiculosum, H. delphicum, and H. olympicum) through GC-MS analysis. Hypericum rumeliacum subsp. apollinis, collected from Mt. Parnassos, exhibited a high abundance of sesquiterpenes hydrocarbons (32.5%) and oxygenated sesquiterpenes (29.7%). Hypericum vesiculosum collected from Mt. Chelmos was rich in oxygenated monoterpenes (33.5%), followed by benzyl derivatives (25.9%). Hypericum delphicum and H. olympicum, collected from the island of Evvia, showed a predominance of alkanes (35.8%) and oxygenated sesquiterpenes (31.9%) in H. delphicum and sesquiterpenes hydrocarbons (41.2%) and oxygenated sesquiterpenes (29.9%) in H. olympicum. Our findings provide new data on the volatile profile of H. vesiculosum and enhance existing information on other species, highlighting notable chemical diversity within the genus Hypericum. Full article

Plant-derived secondary metabolites such as triterpenes and triterpenoids are present in a wide range of plant species. These compounds are particularly attractive due to their extensive range of biological properties and potential applications as intermediates in the synthesis of novel pharmacologically promising medications. Saponins, which are glycosylated triterpenoids found in nature, exhibit the same properties. At this point, the effectiveness of saponins as an anti-inflammatory medication has been verified. This review article examines the primary connections between immune responses and anti-inflammatory activity, focusing specifically on the correlation between triterpenes and triterpenoids. These connections have been investigated in various cell models, as well as in vitro and in vivo studies. The present research provides a comprehensive overview of the current understanding of the therapeutic capabilities of triterpenes and triterpenoids in immune and inflammatory processes. It also highlights emerging standards and their potential utilization in pharmaceutical and clinical settings. Full article

Metal–organic frameworks (MOFs) are also known as porous coordination polymers. This kind of material is constructed with inorganic nodes (metal ions or clusters) with organic linkers and has emerged as a promising class of materials with several unique properties. Well-known applications of MOFs include their use as gas storage and in separation, catalysis, carbon dioxide capture, sensing, slender film gadgets, photodynamic therapy, malignancy biomarkers, treatment, and biomedical imaging. Over the past 15 years, an increasing amount of research has been directed to MOFs due to their advanced applications in fuel cells, supercapacitors, catalytic conversions, and drug delivery systems. Various synthesis methods have been proposed to achieve MOFs with nanometric size and increased surface area, controlled surface topology, and chemical activity for industrial use. In this context, the pharmaceutical industry has been watching the accelerated development of these materials with great attention. Thus, the objective of this work is to study the synthesis, characterization, and toxicity of MOFs as potential technological excipients for the development of drug carriers. This work highlights the use of MOFs not only as delivery systems (DDSs) but also in advanced diagnostics and therapies, such as photodynamic therapy and targeted delivery to tumors. Bibliometric analyses showed a growing interest in the topic, emphasizing its contemporary relevance. Full article

Natural alkylated hydroxy cinnamates (AHCs) isolated from medicinal plants and the thereby designed and synthesized cinnamides are derivatives of hydroxy cinnamic acids such as p-coumaric, sinapic, ferulic, and caffeic acids, which are naturally derived from human dietary sources. The pharmacological properties displayed by AHCs based on their inherent structure range include antioxidant, antimicrobial, antiplasmodial, anti-tyrosinase, Alzheimer’s and Parkinson’s disease therapy, anticancer therapy, metabolic disease therapy, and biopesticides, which have not been reviewed together. Based on their inherent antioxidant, antimicrobial, and UV absorption and their structure–activity relationships, these cinnamyl esters and amides can be used for food preservation in emulsions and oils, as sun-protective components of skin care formulations, and in many other multifunctional applications. In conclusion, the fine-tuning of the structural features such as the type of hydroxy cinnamic acid used, the length of alkyl chains for variable lipophilicity, conversion from cinnamic to propanoic for antioxidants, the increase in methoxy or the change to amino groups to increase the molar absorption coefficient and loss of absorption values, the substitution by halides or amino groups for potent biopesticides, and conversion from esters to amide bonds leads to different AHCs for biomedical, cosmetic, and agriculture applications as an emerging field of investigation that can overall provide natural, safe, biodegradable, and sustainable molecules. Full article

This study evaluates the feasibility and effectiveness of using immobilized pectinase enzymes for juice processing to reduce cloudiness while preserving nutritional and bioactive properties. The research is driven by the increasing demand for innovative food products that offer enhanced functionality and health benefits. It focuses on the development and application of immobilized biocatalysts in bioprocessing, specifically using pectinase encapsulated in a sol–gel matrix. Reaction parameters for the interaction between immobilized pectinase and its primary substrate, pectin, were optimized through systematic experimentation. Optimal conditions were established, achieving enhanced enzyme activity and stability with 0.15 g of lens-shaped capsules containing 10.0 mg/mL pectinase in 24-well microplates as microreactors. Kinetic studies indicated improved substrate affinity after immobilization (K_m = 0.115 mg/mL), particularly when magnetized (K_mi = 0.041 mg/mL). Operational stability and reusability assessments demonstrated potential for extended use with magnetized pectinase capsules retaining higher residual activity after a fourth reuse cycle (155% > 75%). The application of immobilized pectinase in processing peach nectar successfully reduced cloudiness and increased the release of bioactive compounds, enhancing antioxidant and anti-inflammatory activities, as evaluated by the DPPH (2,2-diphenyl-1-picrylhydrazyl) assay and the albumin method, respectively. In vitro digestion studies revealed dynamic activity profile changes, highlighting the impact of juice bioprocessing on bioavailability. Full article

This study investigates the rheological behavior of cellulose microfiber suspensions derived from kahili ginger stems (Hedychium gardnerianum), an invasive species, in two adhesive matrices: a commercial water-based adhesive (Coplaseal^®) and a casein-based adhesive made from non-food-grade milk, referred to as K and S samples, respectively. Rheological analyses were performed using oscillatory and rotational shear tests conducted at 25 °C, 50 °C, and 75 °C to assess the materials’ viscoelastic properties more comprehensively. Oscillatory tests across a frequency range of 1–100 rad/s assessed the storage modulus (G′) and loss modulus (G″), while rotational shear tests evaluated apparent viscosity and shear stress across shear rates from 0.1 to 1000 s⁻¹. Fiber-free samples consistently showed lower moduli than fiber-containing samples at all frequencies. The incorporation of fibers increased the dynamic moduli in both K and S samples, with a quasi-plateau observed at lower frequencies, suggesting solid-like behavior. This trend was consistent in all tested temperatures. As frequencies increased, the fiber network was disrupted, transitioning the samples to fluid-like behavior, with a marked increase in G′ and G″. This transition was more pronounced in K samples, especially above 10 rad/s at 25 °C and 50 °C, but less evident at 75 °C. This shift from solid-like to fluid-like behavior reflects the transition from percolation effects at low frequencies to matrix-dominated responses at high frequencies. In contrast, S samples displayed a wider frequency range for the quasi-plateau, with less pronounced moduli changes at higher frequencies. At 75 °C, the moduli of fiber-containing and fiber-free S samples nearly converged at higher frequencies, indicating similar effects of the fiber and matrix components. Both fiber-reinforced and non-reinforced suspensions exhibited pseudoplastic (shear-thinning) behavior. Fiber-containing samples exhibited higher initial viscosity, with K samples displaying greater differences between fiber-reinforced and non-reinforced systems compared to S samples, where the gap was narrower. Interestingly, S samples exhibited overall higher viscosity than K samples, implying a reduced influence of fibers on the viscosity in the S matrix. This preliminary study highlights the complex interactions between cellulosic fiber networks, adhesive matrices, and rheological conditions. The findings provide a foundation for optimizing the development of sustainable biocomposites, particularly in applications requiring precise tuning of rheological properties. Full article

Advancements in membrane separation techniques will expand the applications and requirements for highly specialized, inventive, efficient, and resistant separation materials. The selective separation of rare earth elements (REEs) is one of the expanding applications of membrane-based techniques, as their use is becoming more widespread. Membrane techniques are becoming increasingly desired as environmentally friendly, straightforward methods for treating wastewater and separating metals. For the separation of REEs, an innovative impregnated mixed-matrix membrane (IMMM) technique was developed in this study. It provides a selective, efficient, and reusable method that is suitable for industrial applications. Terbium was selectively adsorbed from other REEs using organophosphorus IMMM with a loading capacity of 113.2 mg/g in 3 h and was reused three times without destroying the initial membrane. Solvent impregnation is thought to offer specific chelation sites that are selective for terbium separation. Full article

Over the past few years, researchers have developed the alloy Al-Mg-Zn(-Cu), a new aluminum alloy based on the technique of ‘crossover alloying’. The main strengthening phase of this novel alloy is T-Mg₃₂(Al, X)₄₉(X is Zn and Cu) after ageing and hardening. This alloy system has exceptional strength and corrosion resistance, making it a promising candidate for applications in fields like automotive, marine, aerospace, and many others. In this work, the research progress of the Al-Mg-Zn(-Cu) alloy based on microstructure control, composition, design, and properties has been reviewed. Future directions for the research of this alloy are highlighted, too. In this work, crossover alloys are presented as a potential novel class of Al alloys implicating a pioneering design approach, with particular emphasis on the aeronautical and aerospace field in which radiation resistance results are one hundred times higher than traditional precipitation hardening alloys. Full article

Powders with a phase composition including syngenite (K₂Ca(SO₄)₂·H₂O) and/or calcium sulfate dihydrate (gypsum, CaSO₄·2H₂O) were synthesized from the powder of calcium carbonate (CaCO₃) and water solutions of potassium hydrosulfate (KHSO₄) of various concentrations (0.5 M, 1 M, and 2 M). A molar ratio of starting salts, KHSO₄/CaCO₃ = 2, was used to provide the formation of syngenite (K₂Ca(SO₄)₂·H₂O). But when using a 0.5 M water solution of potassium hydrosulfate (KHSO₄), the phase composition of the synthesized powder was presented by calcium sulfate dihydrate (gypsum, CaSO₄·2H₂O). When using 1 M and 2 M water solutions of potassium hydrosulfate (KHSO₄), the syngenite (K₂Ca(SO₄)₂·H₂O) was found as the predominant phase in synthesized powders. According to estimations made from thermal analysis data, powders synthesized using 1.0 M and 2.0 M water solutions of potassium hydrosulfate (KHSO₄) contained no more than 7.9 and 1.9 mass % of calcium sulfate dihydrate (gypsum, CaSO₄·2H₂O), respectively. The phase composition of products isolated from mother liquors via water evaporation consisted of syngenite (K₂Ca(SO₄)₂·H₂O) and potassium sulfate (arcanite, K₂SO₄). Synthesized powders can be used in preparation of biocompatible bioresorbable materials with phase compositions in the K₂O-CaO-SO₃-H₂O system; as matrix of thermo- or photo-luminescent materials; as components reducing the setting time and increasing the strength of sulfate cements; in the fertilizing industry; and also as components of Martian regolith simulants. Full article

The smallest strained, saturated N-heterocycles, such as aziridine, can be a valuable building block in synthetic organic chemistry. Ring-opening reactions with various nucleophiles could be the most important strategy to synthesize various value-added molecular entities. Therefore, regioselective ring-opening reactions of aziridines with various heteroatomic nucleophiles and carbon nucleophiles establish a useful synthetic methodology to synthesize biologically relevant β-functionalized alkylamines. The regio-selective ring-opening of aziridines is highly dependent on the substrate combination, and stereochemical control is challenging for Lewis acid-promoted reactions. Therefore, the development of a robust, catalytic ring-opening process that assists in the accurate prediction of regioselectivity and stereochemistry is highly desirable. Consequently, a large number of publications detailing distinct methods for aziridine ring-opening reactions can be found in the literature. In this review, we discuss several transition metal catalyzed cross-coupling reaction protocols for the ring opening of substituted aziridines with various carbon nucleophiles. Full article

This review discusses the development and applications of bioconjugates derived from natural hydroxycinnamic acids (HCA), such as coumaric, sinapic, ferulic, and caffeic acids, combined with various biomaterials. These bioconjugates offer a range of benefits including antioxidant properties, UV protection, customized hydrophilic–lipophilic balance, improved safety, solubility, emolliency, biocompatibility, biodegradability, and targeted delivery for biomedical, cosmetic, and food applications. The increasing demand for natural products in the biomedical, cosmetic, and food industries has led to the exploration of these hydroxycinnamic acids and their derivatives. We discuss the synthesis and modification of hydroxycinnamic acids with biomaterials such as ω-hydroxy fatty acids, castor and lesquerella oils, glycerol, isosorbides, and synthetic polyethylene glycol to form functional phenolipids for biomedical, sunscreen, and skincare applications. Encapsulation techniques with β-cyclodextrins and modification of polymeric supports like polysaccharides and starch are discussed for enhancing bioavailability and solubility and targeted delivery. The fine-tuned development of bioconjugates from hydroxycinnamic acids using glycerol to modify the hydrophilic–lipophilic balance, substitution by water-soluble carboxylic acid groups, vegetable oil-based phenolipids, polysaccharides, and PEGylation provide enhanced dual functionalities and offer a promising avenue for creating effective products across various applications. Full article