Chemistry, Volume 6, Issue 5 (October 2024) – 28 articles

Solvents can have a tremendous influence on the rate and selectivity of chemical reactions, but their effects are not always well accounted for. In the present work, density functional theory computations are used to investigate the influence of solvent on the Diels–Alder reactions of 9-methylanthracene with (5-oxo-2H-furan-2-yl) acetate and different anhydrides considering the overall reaction rates as well as selectivity between possible isomeric products. Crucially, we find that overall reaction rates are higher in non-polar toluene, whereas selectivity is enhanced in the polar solvent acetone. In the case of (5-oxo-2H-furan-2-yl) acetate, the difference in the reaction barriers is enhanced by 2.4 kJ/mol in acetone as compared to the gas phase, halving the yield of the side product. Similar results are found for the reaction of 9-methylanthracene with chloro-maleic anhydride and cyano-maleic anhydride, highlighting the generality of the trends observed. After presenting the energetics, a detailed discussion of the reactivity is given using electrostatic potentials, frontier orbitals, reactivity indices and Fukui functions. In summary, this study highlights the importance of solvent in influencing reaction rates and illustrates the possibility of studying its effects computationally. Full article

This study investigated the acyl group transfer reactions of 2,4-dinitrophenyl 5-substituted-2-furoates, promoted by 4-substituted phenoxides/phenols in a 20 mol% DMSO aqueous solution at 25 °C. The reactions yielded nucleophilic substitution products and displayed second-order kinetics, with β_acyl values ranging from −2.24 to −2.50, ρ(x) values between 3.18 and 3.56, and β_nuc values of 0.81 to 0.84. These findings indicate an addition–elimination mechanism where the initial step is rate-determining. Comparative analysis with previous data revealed that the transition state structure remained largely consistent when altering the non-leaving group from thienyl to furyl under similar conditions. Notably, a shift in the rate-determining step was observed when changing the nucleophile from secondary amines/ammonium ions to 4-substituted phenoxides/phenols, highlighting the significant impact of nucleophile selection on the reaction kinetics and mechanisms in acyl transfer reactions. Full article

The constructs of lipid molecules follow self-assembly, driven by intermolecular interactions, forming stacking of lipid bilayer films. Achieving designed geometry at nano- to micro-levels with packing deviating from the near-equilibrium structure is difficult to achieve due to the strong tendency of lipid molecules to self-assemble. Using ultrasmall (<fL) droplets containing designed molecules, our prior work has demonstrated that molecular assembly, in principle, is governed mainly by transient inter-molecular interactions under their dynamic spatial confinement, i.e., tri-phase boundaries during drying. As a result, the assemblies can deviate, sometimes significantly, from the near-equilibrium structures of self-assembly. The present work applies the approach and concept to lipid molecules using 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC). Taking advantage of the high spatial precision and the minute size of the delivery probe in our combined atomic force microscopy and microfluidic delivery, the transient shape of each liquid droplet is regulated. In doing so, the final geometry of the POPC assemblies has been regulated to the designed geometry with nanometer precision. The results extend the concept of controlled assembly of molecules to amphiphilic systems. The outcomes exhibit high potential in lipid-based biomaterial science and biodevice engineering. Full article

Small bifunctional molecules are attractive for use as models in different areas of knowledge. How can their functional groups interact in solids? This is important to know for the prediction of the physical and chemical properties of the materials based on them. In this study, two new hydrogen-bonded organic frameworks (HOFs) based on sterically demanding molecular compounds, bis(1-hydroxy-2-methylpropane-2-aminium) sulfate (1) and 2-methyl-4-oxopentan-2-aminium hydrogen ethanedioate hydrate (2), were synthesized and fully characterized by means of FTIR and NMR spectroscopies, as well as by X-ray powder diffraction and thermogravimetric analyses. Their molecular and crystal structures were established through single-crystal X-ray diffraction analysis. It was shown that both compounds have a layered structure due to the formation of a 2D hydrogen-bonding network, the layers being linked by systematically arranged Van der Waals contacts between the methyl groups of organic cations. To unveil some dependencies between the chemical nature of bifunctional molecules and their solid structure, Hirschfeld surface (HS) analysis was carried out for HOFs 1, 2, and their known congeners 1-hydroxy-2-methylpropan-2-aminium hemicarbonate (3) and 1-hydroxy-2-methylpropan-2-aminium (1-hydroxy-2-methylpropan-2-yl) carbamate (4). HS was performed to quantify and visualize the close intermolecular atomic contacts in the crystal structures. It is clearly seen that H–H contacts make the highest contributions to the amino alcohol based compounds 1, 3 and 4, with a maximal value of 65.2% for compound 3 having CO₃²⁻ as a counterion. A slightly lower contribution of H–H contacts (64.4%) was found for compound 4, in which the anionic part is represented by 1-hydroxy-2-methylpropan-2-yl carbamate. The significant contribution of the H–H contacts in the bifunctional moieties is due to the presence of a quaternary carbon atom with a short three-carbon chain. Full article

Macrocycles bridge the gap between conventional small molecules and polymers. Drawing inspiration from successful carbon heteroatom-containing macrocycles, peroxide-containing macrocycles are gaining attention for enhanced bioactivity, potential chelating properties, and applications in energetic materials. This review presents the following strategies for the construction of cyclic peroxides with 10- to 36-membered frameworks: (1) the intramolecular iodocyclization of hydroperoxides, (2) the intermolecular cyclization of hydroperoxides with alkyl dihalides or carbonyls, (3) the acid-catalyzed rearrangements of ozonides or 11-membered cyclic triperoxides via oxy- or peroxycarbenium ions, and (4) the peroxidation of carbonyls targeting macrocyclic peroxides. The specific agents that allow for the selective construction of the medium and large cycles are also analyzed. Full article

For square-planar late transition metal pyridine, diimine (Rh, Ir) complexes with hydro-xido, methoxido, and thiolato ligands. We could previously establish sizable metal-O- and S π-bonding interactions. Herein, we report the hydrogenation studies of iridium hydroxido and methoxido complexes, which quantitatively lead to the trihydride compound and water/methanol. The iridium trihydride displays a highly fluctional structure with scrambling hydrogen atoms, which can be described as a dihydrogen hydride system based on NMR and DFT investigations. This contrasts the iridium sulfur compounds, which are not reacting with dihydrogen. According to DFT and LNO-CCSD(T) calculations, hydrogenation of the methoxido complex proceeds by a two-step mechanism, i.e., an oxidative addition step of H₂ to an Ir(III) dihydride intermediate with consecutive reductive O-H elimination of methanol. Based on PNO-CCSD(T) calculations, the reactivity difference between the O- and S-donors can be traced to the stronger H-O bonds in the water/methanol products compared to the S-H bonds in the sulphur congeners, which serves as a driving force for hydrogenation. Full article

The synthesis of zeolites from natural aluminosilicate minerals has drawn extensive attention due to its significant utility in greening the zeolite manufacturing process. In this study, pure-phase NaX zeolite was synthesized via a low-temperature hydrothermal method, utilizing natural, low-quality attapulgite clay as the raw material. Acidified clay was fully activated through alkali fusion at 200 °C, and the impact of alkali fusion temperature, H₂O/Na₂O ratio, aging temperature, and crystallization time on the resulting crystalline NaX zeolite was investigated. The optimal conditions for obtaining pure NaX zeolite were determined to be alkali melting at 200 °C for 4 h, an H₂O/Na₂O ratio of 50, aging at 40 °C, and a crystallization period of 11 h at 90 °C. With a large BET surface area of 328.43 m²/g, the obtained NaX zeolite was used to adsorb Pb²⁺ from wastewater with a removal rate of 95%. This research provides a valuable method for the extensive and efficient utilization of low-grade natural attapulgite clay. Moreover, this is the first report on the synthesis of pure-phase NaX zeolite using only low-quality natural attapulgite clay as raw material through an atmospheric pressure water bath method. Full article

Chalcones are organic structures that occur naturally in flavonoids and isoflavonoids from diverse vegetables and fruits. Their properties have promising applications in medicinal chemistry as antiparasitic agents against malaria, leishmaniasis, and Chagas disease. Parasitic diseases, a global health challenge, affect thousands of people around the world. The lack of access to affordable treatments causes many deaths, especially in developing countries. Chagas disease, a neglected infection whose etiological agent is the protozoan Trypanosoma cruzi (T. cruzi), is currently incurable without timely treatment and depends on two primary nitrated chemotherapeutic agents: Nifurtimox (Nfx) and Benznidazole (Bzn). However, these drugs exhibit low selectivity and serious adverse effects, accentuating the critical need to develop new, safer chemotherapeutic options. In this context, herein we report the synthesis of halogen chalcone derivatives by an affordable and sustainable method. In vitro studies against T. cruzi demonstrated that the fluorine-containing structures have the best bioactive profile with inhibitions comparable to Nfx and Bzn. Additionally, ADME analysis was performed to determine the crucial physicochemical and pharmacokinetic descriptors of the series of compounds, which were shown to be suitable for enteral absorption and have a low risk of crossing the blood–brain barrier and damaging brain tissue. Full article

A motivating class of compounds with interest in the research field of biological active metallopharmaceuticals for cancer treatment is based on organometallic complexes of Sn(IV), exhibiting advantages such as improved cellular uptake and body excretion, lower toxicity, and fewer side effects compared to platinum-based drugs. In this study, the mononuclear organotin coordination complex [(CH₃)₂SnCl₂(mebta)₂] was synthesized and characterized using vibrational spectroscopy (IR, Raman), ¹H NMR, ¹³C{¹H} NMR, and X-ray crystallography. Its antiproliferative properties were thoroughly assessed across an aggressive triple-negative human breast cancer cell line. Notably, comparative studies with precursor materials verified that the observed biological activity is intrinsic to the complex itself. This study highlights the compound’s ability to induce cell fate by disrupting essential cellular functions, such as proliferation. By exploring the antiproliferative effects of organotin(IV) derivatives, we introduce a novel class of Sn complexes with 1-methylbenzotriazole (mebta), demonstrating significant potential as promising antitumor agents in the field of organotin compounds. Full article

Since ancient times, humans have turned to medicinal plants for treating various ailments and curing specific diseases, as these natural plants serve as the primary source of a range of phytochemicals, including triterpenes. Maslinic acid (MA), also known as (2α,3β)-2,3-dihydroxyolean-12-en-28-oic acid, is a pentacyclic triterpene acid present in numerous plants including olive, known for its high safety profile in humans. Recent experimental data increasingly suggests that MA exhibits diverse biological properties and therapeutic effects on various organ diseases, highlighting its significant potential for clinical applications due to its diverse potential pharmacological activities that promote health and resist various diseases, such as hypoglycemic, neuroprotective, anti-tumor, anti-inflammatory, antioxidant and multiple other biological activities. However, the undesirable pharmacokinetic properties of MA, such as high lipophilicity, pose a limitation to its application and development, impacting its bioavailability. Consequently, extensive research spanning decades has focused on structurally modifying MA to overcome these limitations and enhance its pharmacokinetic and therapeutic characteristics, leading to the identification of several potential lead compounds. In this review, we focus on the progress of research in recent years on MA with interest to its chemical and enzymatic modifications as well as the relationships between the modified structures or derivatives and their biological activities. Full article

4-Acylpyrazolones are important ligands in analytical chemistry and technologies used for the separation and concentration of various metals. We have proposed a novel method for obtaining a material that consists of covalently immobilized functionalized ionic liquid on the surface of a mineral carrier featuring a coordination-active fragment of 4-acylpyrazolone. For its synthesis, we have introduced a strategy based on the quaternization of surface azolyl groups from 3-(1H-imidazol-1-yl)propyl silica with an alkylating reagent containing a 4-acylpyrazolone motif-4-(6-bromohexanoyl)-5-methyl-2-phenyl-2,4-dihydro-3H-pyrazol-3-one. This method of covalent immobilization preserves the 1,3-dioxo fragment, which ensures the effective binding of metal ions. The success of this functionalization has been confirmed by IR and ¹³C NMR spectroscopy data, as well as by thermogravimetric analysis. The overall functional capacity was found to be 0.3 mmol/g. The potential of the synthesized organomineral material to concentrate five rare earth elements (REEs) representing the cerium (Eu(III), Sm(III)) and yttrium groups (Gd(III), Dy(III), Er(III)) has been demonstrated. It was shown that during extraction from multicomponent systems, both under static and dynamic preconcentration conditions, there is a competitive influence of analytes, and their separation can be evaluated under dynamic conditions based on dynamic output curves and calculated distribution coefficients. It was shown that for systems where Kd > 1.8, quantitative separation can be performed in a dynamic mode of sorption under selected conditions. Full article

Titanium dioxide (TiO₂) was added in different proportions as a filler to the mixture for the production of recycled rubber tiles in order to improve their existing properties. The mechanical properties of novel rubber tiles were analyzed in the context of abrasion resistance, maximum stress (TS), stress at break (TSb), deformation at break (Eb), and hardness. An optimal mixture composition was found comparing the obtained results of mechanical tests; successful improvement of abrasion by 22.1%, Eb by 10.46% and hardness by 17.65% was achieved. Finally, the characterization of the new rubber tile by SEM/EDS and FTIR analysis was carried out, along with the stability and environmental impact assessment based on the leaching test. The accelerated aging test was conducted using a solar simulator, after which the mechanical properties, SEM/EDS, FTIR, and leaching test were re-examined. The results after the accelerated aging test showed that tiles with the addition of TiO₂ have better mechanical properties compared to the reference ones; TS improved by 85.71%, Eb by 75.53%, and hardness by 9.43%. Therefore, we concluded that TiO₂ as a filler in interaction with rubber and polyurethane composites significantly contributed to the improvement of the existing rubber tile, and the achieved improvements are useful for the original application of these tiles, which is the protection from injuries on playgrounds and sports fields. Also, the improvement achieved extends the service life of this type of tile, which contributes to the quality of this type of material. Full article

The success of platinum-based chemotherapeutic drugs for clinical cancer treatments has inspired tremendous research efforts on developing new metallic anticancer agents with improved cytotoxic activity and reduced side effects. 2,2′;6′,2″-Terpyridine and its 4′-substituted derivatives have showed great potential as ligand compartments for designing new anticancer drug candidates involving base metals. In this work, we synthesized a series of cobalt and iron coordination compounds based on 4′-pyridyl-2,2′;6′,2″-terpyridine, including homoleptic complexes, a dinuclear bridged complex and 1- and 2-dimensional coordination polymers/networks. The polymorphism of two homoleptic Co^II and Fe^II complexes has been described along with the structural characterization of a Co^II coordination polymer and dinuclear Fe^III complex by X-ray crystallography. These compounds were tested preliminarily as precatalysts for the regioselective hydrosilylation of styrene. Their cytotoxic activities against two human breast cancer cell lines (MCF-7 and MDA-MB 468) and a normal breast epithelial cell line (MCF-10A) were investigated in order to observe the best-performing drug candidates. Full article

Due to its application as an anti-cancer drug, pazopanib (1) has attracted the interest of many researchers, and several studies on pazopanib synthesis have been reported over the years. This paper provides a novel route for synthesizing N,2,3-trimethyl-2H-indazol-6-amine (5), which is a crucial building block in the synthesis of pazopanib from 3-methyl-6-nitro-1H-indazole (6). By alternating between the reduction and two methylation steps, compound 5 was obtained in a yield comparable (55%) to what has been reported (54%). It is noteworthy that the last step of N²-methylation also yielded N,N,2,3-tetramethyl-2H-indazol-6-amine (5′) as a novel compound. Furthermore, the data presented in this paper can serve as a valuable resource for future research aimed at further refining the process of synthesizing pazopanib and its derivatives. Full article

A cubic pyrochlore with the composition Bi_1.865Co_1/2Fe_1/2Ta₂O_9+Δ (space group Fd-3m, a = 10.5013(8) Å) was synthesized from oxide precursors using solid-phase reactions. These ceramics are characterized by a porous microstructure formed by randomly oriented grains of an elongated shape with a longitudinal size of 0.5–1 µm. The electronic state of cobalt and iron ions in oxide ceramics was studied by NEXAFS and XPS spectroscopy. The parameters of the XPS spectra of Bi4f, Bi5d, Ta4f, Co2p, and Fe2p ionization thresholds for a complex pyrochlore were compared with the parameters of the corresponding oxides of the transition elements. The energy position of the XPS-Ta4f and -Ta5p spectra is shifted towards lower energies compared to the binding energy in tantalum(V) oxide by 0.75 eV. According to XPS spectroscopy, bismuth and tantalum cations have the corresponding effective charge of +3 and +(5-δ). The NEXAFS-Fe2p spectrum of ceramics coincides with the spectrum of Fe₂O₃ in its main spectrum characteristics and indicates the content of iron ions in the oxide ceramics in the form of octahedral Fe(III) ions, and according to the character of the Co2p spectrum, cobalt ions are predominantly in the Co(II) state. Full article

To clarify the adsorption behavior of fluorocarbon surfactants on PMMA surfaces, the contact angles of two nonionic fluorocarbon surfactants (FNS-1 and FNS-2) and an anionic fluorocarbon surfactant (FAS) on polymethylmethacrylate (PMMA) surface were determined using the sessile drop method. Moreover, the effects of molecular structures on the surface tension, adhesion tension, solid–liquid interfacial tension, and adhesion work of the three fluorocarbon surfactants were investigated. The results demonstrate that the adsorption amounts for three fluorocarbon surfactants at the air–water interface are 4~5 times higher than those at the PMMA–solution interface. The three fluorocarbon surfactants adsorb on the PMMA surface by polar groups before CMC and by hydrophobic chains after CMC. Before CMC, FNS-2 with the smallest molecular size owns the highest adsorption amount, while FAS with large-branched chains and electrostatic repulsion has the smallest adsorption amount. After CMC, the three fluorocarbon surfactants form aggregates at the PMMA-liquid interface. FAS possesses the smallest adsorption amount after CMC. Besides, FNS-1 possesses a higher adsorption amount than FNS-2 due to the longer fluorocarbon chain and the lower CMC value of FNS-1. The adsorption behaviors of nonionic and anionic fluorocarbon surfactants on the PMMA surface are different. FAS forms interfacial aggregates before CMC, which may be attributed to the electrostatic interaction between the anionic head of FAS and the PMMA surface. Full article

Glioblastoma (GBM) is a malignant cancer affecting the brain. As per the WHO classifications, it is a grade IV glioma and is characterized by heterogenous histopathology, high recurrence rates, and a high median age of diagnosis. Most individuals diagnosed with GBM are aged between 50 and 64 years, and the prognosis is often poor. Untreated GBM patients have a median survival of 3 months, while treatments with Temozolomide (TMZ) and radiotherapy can improve the survival to 10–14 months. Tumor recurrence is common, owing to the inefficiency of surgical resection in removing microscopic tumor formations in the brain. A crucial component of GBM-related research is understanding the tumor microenvironment (TME) and its characteristics. The various cellular interactions in the TME contribute to the higher occurrence of malignancy, resistance to treatments, and difficulty in tumor resection and preventative care. Incomplete pictures of the TME have been obtained in 2D cultures, which fail to incorporate the ECM and other crucial components. Identifying the hallmarks of the TME and developing ex vivo and in vitro models can help study patient-specific symptoms, assess challenges, and develop courses of treatment in a timely manner which is more efficient than the current methods. Microfluidic models, which incorporate 3D cultures and co-culture models with various channel patterns, are capable of stimulating tumor conditions accurately and provide better responses to therapeutics as would be seen in the patient. This facilitates a more refined understanding of the potential treatment delivery systems, resistance mechanisms, and metastatic pathways. This review collates information on the application of such microfluidics-based systems to analyze the GBM TME and highlights the use of such systems in improving patient care and treatment options. Full article

The reactions of the angular ligand 4,4′-oxybis(N-(pyridin-3-yl)benzamide) (L¹) and 1,4-naphthalenedicarboxylic acid (1,4-H₂NDC) with divalent metal salts yielded three distinct coordination polymers (CPs): {[Zn₂(L¹)(1,4-NDC)₂]·MeOH}_n, 1, {[Cu(L¹)(1,4-NDC)(H₂O)]·3H₂O}_n, 2, and {[Cd(L¹)(1,4-NDC)]·2H₂O}_n, 3. Complex 1 features a 2-fold interpenetrated 3D framework with the (4¹²·6³)-pcu topology, while complex 2 reveals a 1D triple-strained helical chain and complex 3 displays a 3-fold interpenetrated 3D framework with (6⁶)-dia topology. Additionally, the reactions of the flexible ligand N,N′-bis(3-methylpyridyl) adipoamide (L²) afforded {[Co₄(L²)_0.5(1,4-NDC)₃(H₂O)₃(µ₃-OH)₂]·EtOH·2H₂O}_n, 4, {[Zn₂(L²)(1,4-NDC)₂]·2CH₃OH}_n, 5, and [Cd(L²)(adipic)(H₂O)]_n (H₂adipic = adipic acid), 6, exhibiting a self-catenated 3D framework with the (4²⁰·6⁸)-8T32 topology, a 2D layer with the (4¹³·6²) − (4,4)IIb topology, and a 2D layer with the (4⁴·6²)-sql topology, respectively. The structural diversity observed in complexes 1–6 highlights the pivotal influence of the metal center on the degree of entanglement in CPs within mixed-ligand systems. The thermal stability and luminescent properties of complexes 1–3, 4, and 6 are also discussed. Full article

In recent years, transdermal drug delivery systems have gained considerable attention for their ability to enhance patient compliance and provide consistent drug release. However, the barrier function of the skin’s outermost layer remains the foremost challenge in these systems. As a result, there is a growing interest in the use of ethosomes as a cutting-edge nanocarrier in drug delivery. This review presents the concept and mechanism of action of ethosomes as well as the numerous types and preparation techniques available. It also discusses the significance of characterization methods and how they impact ethosomal properties along with recent advancements and applications in the realm of transdermal drug delivery. Ethosomes exhibit tremendous potential for the pharmaceutical industry, and optimizing preparation methods, performing comprehensive property studies, and exploring their applications are critical areas for future research. Full article

Fluorometric method for detecting of five nitrogen-based drugs concentration based on inhibition of emission Eosin Y (EY). The selection of N-drugs comprised indapamide (INDP), clomipramine hydrochloride (CMI), promethazine hydrochloride (PMH), lisinopril (LSP), and trifluoperazine hydrochloride (TFPH). The Stern–Volmer style was plotted between relative emissions of EY vs. N-drugs concentration. The standard curves were linear over the concentration range of 5–50 µg mL⁻¹ with R² > 0.9, and the LOD for INDP, CMI, PMH, LSP, and TFPH were 2.07, 1.36, 3.02, 3.52, and 2.09 µmol·L⁻¹, respectively. The binding constant $K_{app}$ for LSP was greater than other N-drugs. Furthermore, the suggested method was hence applied for the routine detection of the concentration of N-drugs in bulk and tablet or syrup dosage forms. FTIR analysis and the electron-mapping density provided the chemical affinity of N-drugs towards EY. Full article

Due to a combination of increased urbanization, industrialization, and population growth, many pharmaceutical pollutants are currently being discharged into the environment. A possible strategy is critical for eliminating antibiotic pollutants from the environment, and photocatalysis has been generally recognized as an excellent method for successfully degrading antibiotics at a faster pace. In this work, we employed a hydrothermal synthesis approach to create a novel C₃N₅/NiCo₂S₄ Z-scheme-based heterojunction with better interfacial charge transfer and used it as a catalyst for the degradation of norfloxacin antibiotic. The optimized 1:1 C₃N₅/NiCo₂S₄ (50CN/NCS) shows the highest photocatalytic efficiency of 86.5% in 120 min towards the degradation of norfloxacin (NOR). Such an effective performance can be attributed to the high responsive nature of photocatalyst in the visible region and superior transfer of interfacial charges via Z-scheme transfer in heterojunction. The high charge transfer efficiency and reduced recombination of charge carriers in heterojunction was confirmed by EIS and PL results. The influence of some key factors such as pollutant concentration, catalyst dosage, pH, and coexisting ions on the photocatalytic activity is also investigated in this work. The optimized heterojunction 50CN/NCS also degraded 89.1%, 78.3%, and 93.2% removal of the other pollutants CIP, SDZ, and BPA, respectively. Full article

Polyols such as 1,5-pentadiol, 1,6-hexanediol, and 1,2,6-hexanetriol are crucial chemicals, traditionally derived from non-renewable fossil sources. In the pursuit of sustainable development, exploring renewable and environmentally benign routes for their production becomes imperative. Furfural and 5-hydroxymethylfurfural are C₅ and C₆ biomass-derived platform molecules, which have potential in the synthesis of various polyols through hydrogenation and hydrogenolysis reactions. Currently, there is an extensive body of literature exploring the transformation of biomass-derived furan compounds. However, a comprehensive review of the transformation of furan compounds to polyols is lacking. We summarized the literature from recent years about the ring-opening reaction involved in converting furan compounds to polyols. This article reviews the research progress on the transformation of furfural, furfuryl alcohol, and 2-methylfuran to 1,2-pentadiol, 1,4-pentadiol, 1,5-pentadiol, and 1,2,5-pentanetriol, as well as the transformation of 5-hydroxymethylfurfural to 1,2-hexanediol, 1,6-hexanediol, and 1,2,6-hexanetriol. The effects of the supported Pd, Pt, Ru, Ni, Cu, Co, and bimetallic catalysts are discussed through examining the synergistic effects of the catalysts and the effects of metal sites, acidic/basic sites, hydrogen spillover, etc. Reaction parameters like temperature, hydrogen pressure, and solvent are considered. The ring opening catalytic reaction of furan rings is summarized, and the catalytic mechanisms of single-metal and bimetallic catalysts and their catalytic processes and reaction conditions are discussed and summarized. It is believed that this review will act as a key reference and inspiration for researchers in this field. Full article

Background: Small molecules play a crucial role in the exploration of physiological pathways and in drug development by targeting deoxyribonucleic acid (DNA). DNA is a central focus for both endogenous and exogenous ligands, which interact directly or indirectly to regulate transcription and replication processes, thus controlling genetic expression in specific cells. Among these molecules, indole derivatives like tryptophan, serotonin, and melatonin are notable for their widespread presence in nature and significant biological effects. Tryptophan, an essential amino acid, serves as a vital structural element in proteins and a precursor for bioactive compounds like serotonin and melatonin, which impact various physiological functions. Methods: Experimental studies have been conducted to reveal the interaction mechanisms of these endogenous indole derivatives with calf thymus DNA (ct-DNA). These investigations involve viscosity measurements and analysis of double-stranded DNA behavior in the presence of indole molecules, using spectrophotometric UV absorption techniques to assess their impact on DNA stability. Additionally, the influence of calcium and magnesium ions on the resulting complexes of these indole derivatives with ct-DNA has been evaluated. Molecular docking validated our findings, offering additional insights into potential DNA–ligand interactions. Utilizing a crystallographic oligomer with an intercalation gap improved docking accuracy, distinguishing intercalation from groove recognition and enhancing assessment precision. Results: Our study offers detailed insights into the interaction patterns of the indole derivatives with DNA and is highly supported by molecular docking analyses: the indole derivatives were predominantly localized between C and G, interacting via π-π interactions and hydrogen bonds and aligning with known data on conventional intercalators. These findings underscore the importance of small compounds’ planar structure and appropriate size, facilitating tight insertion between adjacent base pairs and disrupting regular DNA stacking. Conclusions: Indoles’ physiological roles and potential as drug candidates targeting specific pathways are highlighted, emphasizing their significance as ubiquitous molecules with the ability to modulate biological effects on DNA structure. Full article

In order to explore the possibilities of increasing the hydrophilicity of carbon-based adsorbents, catalysts, or electrode materials in aqueous solutions, the oxidation of wood-based activated biochar using H₂O₂ was investigated. The properties of oxidized activated biochar obtained at different activation temperatures (600, 700, and 800 °C) and H₂O₂ oxidized for 15–180 min were investigated using the characteristics of surface functionality, elemental composition, porous structure, contact angle measurements, FTIR spectroscopy, and immersion calorimetry. It was observed that the optimal oxidation time was different for each sample depending on activation temperature, and the degree of oxidation can be tailored by changing the oxidation time. The course of oxidation depends on the degree of graphitization and functionalization, determined by the activation temperature. It was established that the highest degree of oxidation and increase in wettability is observed for samples with the lowest degree of activation obtained at a temperature of 600 °C. Full article

Starting from the well known stable free radical DPPH (or its reduced counterpart, 2,2-diphenyl-1-picryl-hydrazine) and several amino derivatives, novel zwitterionic compounds (diazenium betaines) were obtained and characterized by different means, like NMR, IR, MS, and UV–Vis. These betaines are highly intense blue-colored compounds that can be easily reduced by ascorbic acid (vitamin C) or sodium ascorbate to their corresponding para-phenyl substituted derivatives of DPPH, which have a yellow color. Most of such redox processes were found to be reversible. However, the oxidation of 2-p-aminophenyl-2-phenyl-1-picryl-hydrazine led to an azo-derivative of DPPH diradical, and its structure was unveiled by X-ray monocrystal diffraction. Possible diradicaloid behavior is also discussed. Full article

Microorganisms remain in water from various sources after desalination and other treatments, posing health risks. We explored alternative natural disinfection agents, focusing on grape seed extract (GSE). We collected local grape seeds in Saudi Arabia and analyzed their chemical components. Using gas chromatography–mass spectrometry and inductively coupled plasma mass spectrometry, we identified essential phytochemicals in the GSE, including polyphenols, flavonoids, and alkaloids. Notably, the GSE was free from bacteria and heavy-metal contamination and rich in beneficial nutrient metals. We conducted qualitative analyses on local water and urine samples to detect bacterial infections, heavy metals, and minerals. To assess GSE’s antibacterial potential, we performed molecular docking analysis. Our results reveal a strong binding energy between GSE and bacterial protein receptors, parallel to that of standard antibiotics. Additionally, the results of the laboratory pilot investigations align with those of computational analyses, confirming GSE’s efficacy. Agar well diffusion tests demonstrated significantly greater zones of inhibition for the crude oil extract compared with both diluted GSE and the positive control against the bacteria detected in the water and urine samples. Furthermore, we identified contamination by four bacterial strains and heavy metals in water samples and female urine samples, highlighting the need for effective water disinfectants. GSE shows promise as a safe and potent natural water disinfectant. Full article

The surface thermodynamic properties of polymers and copolymers modified by supramolecular structures are used in several industrial processes, such as selective adsorption, paints, coatings, colloids, and adhesion applications. Background: Inverse gas chromatography at infinite dilution was proved to be the best technique to determine the surface properties of solid surfaces by studying the adsorption of some model polar and non-polar organic molecules adsorbed on solid surfaces at different temperatures. Methods: The retention volume of adsorbed solvents is a valuable parameter that was used to obtain the London dispersive and polar free energies and the London dispersive surface energy of styrene–divinylbenzene copolymer modified by supramolecular structure of melamine using both the Hamieh thermal model and our new methodology consisting of the separation of the two polar molecules and the dispersive free energy of their interaction. This led to the determination of the polar acid and base surface energy, and the Lewis acid–base constants of the various solid materials. Results: Following our new methodology, all surface energetic properties of styrene–divinylbenzene copolymer modified by melamine at different percentages were determined as a function of temperature. Conclusions: It was observed that the styrene–divinylbenzene copolymer exhibited the highest London dispersive surface energy, which decreased when the melamine percentage increased. All materials presented higher Lewis basicity and this Lewis basicity increased with the percentage of melamine. Full article

Acenes, as a class of polycyclic aromatic hydrocarbons, attract considerable attention due to their remarkable nonlinear optical and magnetic properties. The aim of this work was the elucidation of the capability of radical-substituted acene derivatives to undergo spin-state-switching rearrangements. For this purpose, a series of acene-based (anthracene, pentacene, heptacene) molecules bearing fluorenyl and tert-butyl-nitroxyl radicals were investigated through comprehensive quantum chemical modeling of their electronic structures, isomerization and magnetic properties. A possible mechanism of the transformation of the closed-shell folded isomer into the biradical twisted structure of the bis-fluorenyl anthracene has been ascertained by applying the procedure of searching for the Minimum Energy Crossing Point. The conditions favoring the occurrence of spin-state-switching in such classes of polycyclic aromatic hydrocarbon derivatives have been formulated. By varying the size of an acene core and the type of radical substituent, the compounds capable of changing their magnetic properties have been revealed. Considering the unique features of radical-bearing acene-based derivatives, the proposed molecules can be used as functional materials in photonics and electronics. Full article