Search Results (53)

Benzene-1,2,4-triyl tris(2-(3-carboxy-4-hydroxybenzenesulfonate) acetate) synthesis is an important step forward in the synthesis of multifunctional organic molecules, which have potential uses in material science and medical chemistry, among other domains. In analytical chemistry, it can also be utilized for metal ion determination. This work presents a thorough and methodical approach to the synthesis of this complicated trisulfonated aromatic ester, emphasizing the effectiveness and scaling possibilities of the methodology. Choosing the right precursors to ensure that each one would contribute to the intended molecular architecture was the first step in the synthesis process. In the initial stages of the synthesis process, oxyhydroquinone was reacted with chloroacetyl chloride for 20 h. As a result, benzene-1,2,4-triyl tris(2-chloroacetate) of triatomic phenol-oxyhydroquinone was formed. The resulting phenacetyl chloride was reacted with sodium sulfosalicylate in the presence of N,N-dimethylformamide (DMFA). Benzene-1,2,4-triyl tris(2-(3-carboxy-4-hydroxybenzenesulfonate) acetate) was formed. To obtain high yields and purity, careful adjustment of the reaction conditions that including temperature, solvent selection, and reagent ratios was required. The synthesized molecule was characterized using advanced spectroscopic techniques such as NMR, IR, and UV spectrometry, which confirmed its structural integrity and functional group configuration. Benzene-1,2,4-triyl tris(2-(3-carboxy-4-hydroxybenzenesulfonate) acetate), the resultant product, has special physicochemical characteristics. In particular, it is more soluble and has the potential to be a useful intermediate in organic synthesis. Because it has several reactive sites, preliminary research indicates that it may be useful in the development of new polymeric materials and as a possible ligand in coordination chemistry. Full article

N,N,N′-tris(trimethylsilyl)-carboximidamides are effective reagents in synthetic chemistry in reactions with both non-metal and metal halides, because the side product is the mild and volatile ClSi(CH₃)₃ rather than corrosive HCl. The title compound inserts the 2-pyridylamidinate fragment into several non-metal systems, including custom chelating radical ligands. The single-crystal X-ray diffraction structure was determined and modeled by Hirshfeld atom refinement using custom aspherical atomic scattering factors. Excellent data quality led to a model with enhanced precision of all interatomic distances and free refinement of H-atom positions and anisotropic displacement ellipsoids. This structure model is compared to the four previously published analogous structures. Full article

The reaction in reagent grade acetone of copper(II) nitrate hexahydrate, 2,2′-bipyrimidine (bpm) and potassium iodide in a 1:2:2 molar ratio afforded three different products: an unreduced Cu(II) species, a fully reduced Cu(I) species and a mixed-valent Cu(II)/Cu(I) species. Of these, only the unreduced Cu(II) complex of formula [Cu^II(bpm)₃](I₃)(I) (1) could be structurally characterized, the other two products being initially only isolated as amorphous powders. X-ray quality, beautifully shaped, quasi-black prismatic crystals of compound 2, namely {[Cu^I(I₃)Cu^II(I)(bpm)₂](I₃)}_n, and brick-reddish parallelepipeds of compound 3, namely {[Cu^I₂ (μ-I)₂(bpm)]}_n, were successively obtained through the slow diffusion in H-shaped tubes of aqueous solutions of the three reagents, after extensive optimization of the crystallization conditions. Compound 1 consists of a rare tris(2,2′-bipyrimidine)copper(II) monomeric dication, charge balanced by both iodide and triiodide anions. Compound 3, whose structure as well as optical and photocatalytic properties were recently disclosed, consists of a regular alternating μ-bpm/di-μ-iodide copper(I) chain. Finally, compound 2 consists of a rare, regular alternating mixed-valent Cu(II)-Cu(I) μ-bpm copper chain, showing unusual similarities in the metal coordination environment. The magnetic properties of compound 2 remarkably reveal a very weak antiferromagnetic coupling between the paramagnetic Cu(II) ions which are well separated both intra- and inter-chain. Full article

Background/Objectives: Antibiotic-resistant Staphylococcus aureus represents a growing threat in the modern world, and new antibiotic targets are needed for its successful treatment. One such potential target is the pyridoxal-5′-phosphate (PLP)-dependent cysteine desulfurase (SaSufS) of the SUF-like iron–sulfur (Fe-S) cluster biogenesis pathway upon which S. aureus relies exclusively for Fe-S synthesis. The current methods for measuring the activity of this protein have allowed for its recent characterization, but they are hampered by their use of chemical reagents which require long incubation times and may cause undesired side reactions. This problem highlights a need for the development of a rapid quantitative assay for the characterization of SaSufS in the presence of potential inhibitors. Methods: A spectrophotometric assay based on the well-documented absorbance of PLP intermediates at 340 nm was both compared to an established alanine detection assay and used to effectively measure the activity of SaSufS incubated in the absence and presence of the PLP-binding inhibitors, D-cycloserine (DCS) and L-cycloserine (LCS) as proof of concept. Methicillin-resistant S. aureus strain LAC was also grown in the presence of these inhibitors. Results: The Michaelis–Menten parameters k_cat and K_m of SaSufS were determined using the alanine detection assay and compared to corresponding intermediate-based values obtained spectrophotometrically in the absence and presence of the reducing agent tris(2-carboxyethyl)phosphine (TCEP). These data revealed the formation of both an intermediate that achieves steady-state during continued enzyme turnover and an intermediate that likely accumulates upon the stoppage of the catalytic cycle during the second turnover. The spectrophotometric method was then utilized to determine the half maximal inhibitory concentration (IC₅₀) values for DCS and LCS binding to SaSufS, which are 2170 $\pm$ 920 and 62 $\pm$ 23 μM, respectively. Both inhibitors of SaSufS were also found to inhibit the growth of S. aureus. Conclusions: Together, this work offers a spectrophotometric method for the analysis of new inhibitors of SufS and lays the groundwork for the future development of novel antibiotics targeting cysteine desulfurases. Full article

Pancreatic cancer (PC) is the seventh most common cause of cancer-related death worldwide. The low survival rate may be due to late diagnosis and asymptomatic early-stage disease. Most patients are diagnosed at an advanced stage of the disease. The search for novel prognostic factors is still needed. Two miRNAs, miR-22-3p and miR-885-5p, which show increased expression in PC, were selected for this study. The aim of this study was to evaluate the utility of these miRNAs in the prognosis of PC. Other prognostic factors such as lipase-to-amylase ratio (LAR), neutrophil-to-lymphocyte ratio (NLR), and carbohydrate antigen 19-9 (CA19-9) were also evaluated in this study. This study was conducted in 50 patients previously diagnosed with pancreatic ductal adenocarcinoma in clinical stage (CS) III and IV. All patients underwent a complete medical history, physical examination, and routine laboratory tests including a complete blood count, C-reactive protein (CRP), CA19-9, lipase, and amylase. Two additional blood samples were taken from each patient to separate plasma and serum. Isolation of miRNA was performed using TRI reagent with cel-miR-39-3p as a spike-in control. Reverse transcription of miRNA was performed using a TaqMan Advanced miRNA cDNA Synthesis Kit. The relative expression levels of miR-22-3p and miR-885-5p were measured using RT-qPCR. Serum hsa-miR-22-3p was detected in 22 cases (44%), while hsa-miR-885-5p was detected in 33 cases (66%). There were no statistically significant differences in serum or plasma miRNA expression levels between patient groups based on clinical stage, gender, or BMI. There were no statistically significant differences in LAR between patients with different CS. For NLR, CRP and CA19-9 thresholds were determined using ROC analysis (6.63, 24.7 mg/L and 4691 U/mL, respectively). Cox’s F test for overall survival showed statistically significant differences between groups (p = 0.002 for NLR, p = 0.007 for CRP and p = 0.007 for CA19-9). Utility as prognostic biomarkers was confirmed in univariate and multivariate analysis for CA19-9, CRP, and NLR. The selected miRNAs and LAR were not confirmed as reliable prognostic markers in PC. Full article

RNA quality and integrity are critical for many studies in plant molecular biology. However, extracting high-quality RNA from cereal grains is challenging due to the presence of polysaccharides, polyphenols, and other compounds that bind or coprecipitate with RNA particles. To address this, we introduced an initial purification step into the Tri Reagent Solution protocol, which effectively eliminated starch and other contaminants. The performance of this modified protocol was then compared with five other RNA extraction methods, including those based on Tri Reagent Solution and the Direct-zol RNA Miniprep Plus Kit. Introducing our method modification prior to homogenization with Tri Reagent Solution successfully yielded total RNA with both high quality (RIN values ranging from 9.50 to 9.70) and high efficiency, making it suitable for both mRNA extraction using the Dynabeads mRNA Purification Kit and library preparation for transcriptome sequencing by long-read methods, such as Oxford Nanopore Technologies. The protocol was successfully applied to total RNA extraction from rye grains at 14 and 21 days after pollination. This study demonstrates that improving the Tri Reagent Solution protocol through initial purification enables the extraction of high-quality RNA from rye grains. Full article

Acrylamide (ACR) is a low-molecular weight, non-aromatic reagent, widely used in industry, such as in the manufacture of paper, textiles, plastics, cosmetics, and dyes. ACR is formed during the cooking of starchy food and its toxicity results mainly by conferring oxidative stress by elevating reactive oxygen species (ROS). To identify potential antidotes for ACR toxicity, we evaluated the efficacy of several thiol-based molecules known for ROS-scavenging, disulfide-reducing properties, and inhibition of oxidative stress-induced activation of the mitogen-activated protein kinases (MAPKs): the extracellular-signal-regulated-kinases (ERK1/2), p38-mitogen-activated-protein-kinases (p38^MAPK), and c-Jun-N-terminal-kinases (JNKs). We established a reproducible assay testing N-acetylcysteine (NAC), AD4/NACA, and the N-and C-blocked tri- and tetra-thioredoxin-mimetic (TXM) peptides, in PC12 cells. Our results demonstrate that these compounds exhibited high efficacy in suppressing ACR-induced MAPK activation, either prior to or subsequent to ACR exposure. The inhibition by single cysteine (Cys) residue, NAC and AD4/NACA (NAC-amide), 2 Cys peptides TXM-CB30, AcDCys-Gly-DCysNH₂, TXM-CB20, AcCys-Gly-CysNH₂, SuperDopa (SD, Ac-CysL-Levodopa-CysNH₂, TXM-CB13, AcCys-Met-Lys-CysNH₂, and a 3-Cys peptide, TXM-CB16, AcCys-γGlu-Cys-CysNH₂ was dose-dependent and potency displayed a direct correlation with the number of Cys residues. Cellular proteolysis of SD, which consists of levodopa flanked by two Cys, may suppress the manifestation of Parkinson’s disease (PD)-like symptoms mediated by chronic ACR exposure not only through lowering oxidative stress but also by replenishing cellular levels of dopamine. Overall, these results could advance the clinical application of TXM peptides as potential treatments for acute and/or chronic exposure to ACR and show promise as antidotes for preventing ACR-triggered PD-like neurotoxic symptoms. Full article

We report the synthesis of novel cobalt complexes-based catalysts designed for the oscillatory Belousov–Zhabotinsky (BZ) reaction. For the first time, we introduce cobalt complex-based self-oscillating gels that demonstrate autonomous color oscillations within a BZ reagent solution, functioning without the need for any external stimuli. We created acrylamide-based self-oscillating gels containing immobilized tris(2,2′-bipyridine)cobalt(II) or tris(1,10-phenanthroline)cobalt(II) complexes and gels containing covalently bound (5-acrylamido-1,10-phenanthroline)bis(2,2′-bipyridine)cobalt(II), (5-acrylamido-1,10-phenanthroline)bis(1,10-phenanthroline) cobalt(II), or tris(5-acrylamido-1,10-phenanthroline)cobalt(II) complexes. When the BZ reaction takes place within the gels, it results in the observation of moving chemical waves and reversible color changes. We believe that Co-complexes-based self-oscillating gels have potential applications in the design of soft actuators and chemical devices for signal processing. Full article

Ball milling, as a cost-effective and eco-friendly approach, has been popular in materials synthesis to solve problems involving toxic reagents, high temperatures, or high pressure, which has the potential for large-scale production. However, there are few reviews specifically concentrating on the latest progress in materials characteristics before and after ball milling as well as the adsorptive application for aqueous pollutants. Hence, this paper summarized the principle and classification of ball milling and reviewed the advances of mechanochemical materials in categories as well as their adsorption performance of organic and inorganic pollutants. Ball milling has the capacity to change materials’ crystal structure, specific surface areas, pore volumes, and particle sizes and even promote grafting reactions to obtain functional groups to surfaces. This improved the adsorption amount, changed the equilibrium time, and strengthened the adsorption force for contaminants. Most studies showed that the Langmuir model and pseudo-second-order model fitted experimental data well. The regeneration methods include ball milling and thermal and solvent methods. The potential future developments in this field were also proposed. This work tries to review the latest advances in ball-milled materials and their application for pollutant adsorption and provides a comprehensive understanding of the physicochemical properties of materials before and after ball milling, as well as their effects on pollutants’ adsorption behavior. This is conducive to laying a foundation for further research on water decontamination by ball-milled materials. Full article

Perylenediimides (PDIs) are composed of a central perylene ring, on which are grafted two imide groups at the peri positions. Thionated PDIs are characterized by the substitution of one or more oxygen atoms of these imide functions with sulfur atoms. This structural modification alters the electronic properties with a redshift of the optical absorption accompanied by modification of the charge transport characteristics compared to their non-thionated counterparts. These properties make them suitable candidates for applications in optoelectronic devices, such as organic light-emitting diodes and organic photovoltaics. Moreover, the presence of sulfur atom(s) can favor the promotion of reactive oxygen species production for photodynamic and photothermal therapies. These thionated PDIs can be synthesized through the post-functionalization of PDIs by using a sulfurizing reagent. Nevertheless, the main drawbacks remain the difficulties in adjusting the degree of thionation and obtaining tri- and tetrathionated PDIs. Up to now, this thionation reaction has been described almost exclusively using Lawesson’s reagent. In the current study, we present our first investigations into an alternative reagent to enhance selectivity and achieve a greater degree of thionation. The association of phosphorus pentasulfide with hexamethyldisiloxane (Curphey’s reagent) clearly demonstrated higher reactivity compared with Lawesson’s reagent to attain multi-thionated PDIs. Full article

Fluorescence induced by the excitation of a fluorophore with plane-polarized light has a different polarization depending on the size of the fluorophore-containing reagent and the rate of its rotation. Based on this effect, many analytical systems have been implemented in which an analyte contained in a sample and labeled with a fluorophore (usually fluorescein) competes to bind to antibodies. Replacing antibodies in such assays with aptamers, low-cost and stable oligonucleotide receptors, is complicated because binding a fluorophore to them causes a less significant change in the polarization of emissions. This work proposes and characterizes the compounds of the reaction medium that improve analyte binding and reduce the mobility of the aptamer–fluorophore complex, providing a higher analytical signal and a lower detection limit. This study was conducted on aflatoxin B1 (AFB1), a ubiquitous toxicant contaminating foods of plant origins. Eight aptamers specific to AFB1 with the same binding site and different regions stabilizing their structures were compared for affinity, based on which the aptamer with 38 nucleotides in length was selected. The polymers that interact reversibly with oligonucleotides, such as poly-L-lysine and polyethylene glycol, were tested. It was found that they provide the desired reduction in the depolarization of emitted light as well as high concentrations of magnesium cations. In the selected optimal medium, AFB1 detection reached a limit of 1 ng/mL, which was 12 times lower than in the tris buffer commonly used for anti-AFB1 aptamers. The assay time was 30 min. This method is suitable for controlling almond samples according to the maximum permissible levels of their contamination by AFB1. The proposed approach could be applied to improve other aptamer-based analytical systems. Full article

The removal of harmful arsenic(V) from aqueous solutions using Cyanex 923 (solvation extractant) was investigated using various experimental variables: equilibration time, the acidity of the aqueous phase, temperature, extractant and arsenic concentrations, and O/A ratio. Cyanex 923 extracted As(V) (and sulfuric acid) from acidic solutions; however, it could not be used to remove the metal from slightly acid or neutral solutions. The extraction of arsenic is exothermic and responded to the formation of H₃AsO₄·nL species in the organic phase (L represents the extractant, and the stoichiometric factor, n = 1 or 2, depends on the acidity of the aqueous phase). Extraction isotherms are derived from the experimental results. Both arsenic and sulfuric acid loaded onto the organic phase can be stripped with water, and stripping isotherms are also derived from the experimental results. The selectivity of the system against the presence of other metals (Cu(II), Ni(II), Bi(III), and Sb(III)) is investigated, and the ability of Cyanex 923 to extract As(V) and sulfuric acid compared to the use of other P=O-based solvation reagents, such dibutyl butylphosphonate (DBBP) and tri-butyl phosphate (TBP), is also investigated. Full article

A lot of nanomaterials have been applied to various nano-biotechnological fields, such as contrast agents, drug or gene delivery systems, cosmetics, and so on. Despite the expanding usage of nanomaterials, concerns persist regarding their potential toxicity. To address this issue, many scientists have tried to develop biocompatible nanomaterials containing phytochemicals as a promising solution. In this study, we synthesized biocompatible nanomaterials by using gallic acid (GA), which is a phytochemical, and coating it onto the surface of iron oxide nanoparticles (IONPs). Importantly, the GA-modified iron oxide nanoparticles (GA-IONPs) were successfully prepared through environmentally friendly methods, avoiding the use of harmful reagents and extreme conditions. The presence of GA on the surface of IONPs improved their stability and bioactive properties. In addition, cell viability assays proved that GA-IONPs possessed excellent biocompatibility in human dermal papilla cells (HDPCs). Additionally, GA-IONPs showed antioxidant activity, which reduced intracellular reactive oxygen species (ROS) levels in an oxidative stress model induced by hydrogen peroxide (H₂O₂). To investigate the impact of GA-IONPs on exosome secretions from oxidative stress-induced cells, we analyzed the number and characteristics of exosomes in the culture media of HDPCs after H₂O₂ stimulation or GA-IONP treatment. Our analysis revealed that both the number and proportions of tetraspanins (CD9, CD81, and CD63) in exosomes were similar in the control group and the GA-IONP-treated groups. In contrast, exosome secretion was increased, and the proportion of tetraspanin was changed in the H₂O₂-treated group compared to the control group. It demonstrated that treatment with GA-IONPs effectively attenuated exosome secretion induced by H₂O₂-induced oxidative stress. Therefore, this GA-IONP exhibited outstanding promise for applications in the field of nanobiotechnology. Full article

For the first time, cobalt ferrite spinel (CoFe₂O₄) was used as a catalyst in the Fenton process for Remazol Red RR dye degradation in water. CoFe₂O₄ was synthesized via gel combustion using tris(hydroxymethyl)aminomethane as an alternative fuel in one step with a ratio of Ψ = 0.8. Its structural, surface optics, magnetic properties, and the optimal conditions of the Fenton reagents for dye degradation were evaluated. The saturation magnetization and remanence (Ms and Mr, respectively) for the as-prepared powder were 65.7 emu/g and 30.4 emu/g, respectively, and the coercivity (Hc) was 1243 Oe, indicating its ferromagnetic nature and suitability as a magnetic catalyst. Red Remazol RR dye degradation tests were performed using the Fenton process to evaluate the influence of the catalyst dosage and H₂O₂ concentration. The tests were performed in a batch reactor in the dark with constant agitation for 24 h. The best result was obtained using 1 g/L of catalyst with a dye degradation of 80.6%. The optimal concentration of H₂O₂ (1.0 M) resulted in 96.5% dye degradation. Nanoparticle recyclability testing indicated that the material could be satisfactorily reused as a catalyst for at least three cycles. The potential use of the CoFe₂O₄ synthesized in this study as a catalyst for dye degradation by the Fenton process was demonstrated. Full article

The Aglaia genus, a member of the Meliaceae family, is generally recognized to include a number of secondary metabolite compounds with diverse structures and biological activities, including triterpenoids. Among the members of this genus, Aglaia cucullata has been reported to have unique properties and thrives exclusively in mangrove ecosystems. This plant is also known to contain various metabolites, such as flavaglines, bisamides, and diterpenoids, but there are limited reports on the isolation of triterpenoid compounds from its stem bark. Therefore, this research attempted to isolate and elucidate seven triterpenoids belonging to dammarane-type (1–7) from the stem bark of Aglaia cucullata. The isolated compounds included 20S,24S-epoxy-3α,25-dihydroxy-dammarane (1), dammaradienone (2), 20S-hydroxy-dammar-24-en-3-on (3), eichlerianic acid (4), (20S,24RS)-23,24-epoxy-24-methoxy-25,26,27-tris-nor dammar-3-one (5), 3α-acetyl-cabraleahydroxy lactone (6), and 3α-acetyl-20S,24S-epoxy-3α,25-dihydroxydammarane (7). Employing spectroscopic techniques, the chemical structures of the triterpenoids were identified using FTIR, NMR, and HRESITOF-MS. The cytotoxic activity of compounds 1–7 was tested with the PrestoBlue cell viability reagent against MCF-7 breast cancer, B16-F10 melanoma, and CV-1 normal kidney fibroblast cell lines. The results displayed that compound 5 had the highest level of bioactivity compared to the others. Furthermore, the IC₅₀ values obtained were more than 100 μM, indicating the low potential of natural dammarane-type triterpenoids as anticancer agents. These findings provided opportunities for further studies aiming to increase their cytotoxic activities through semi-synthetic methods. Full article