Search Results (643)

The reaction mechanism of the gold-catalyzed hydrothiolation of alkenes (1) with thiols (2) has been investigated in detail. The tetranuclear gold complex, (PPh₃)₄Au₄(SPh)₂(NTf)₂ (A), is a key intermediate in the catalytic hydrothiolation of alkenes. It forms instantaneously when PPh₃AuNTf₂ and PhSH are mixed in THF. Monitoring the reaction over time using ³¹P NMR spectroscopy revealed that gold complex A remained stable in the reaction system throughout the hydrothiolation process. In addition, we successfully observed a rapid ligand-exchange reaction between the thiolate group of gold complex A and thiols in solution. The gold-catalyzed alkene hydrothiolation reaction has been applied to the catalytic hydrothiolation of allenes, which have degenerate double bonds. Hydrothiolation of allenes proceeded regioselectively at the terminal double bond. However, the yield was lower than that observed for alkenes, and catalyst deactivation occurred. The hydrothiolation products of allenes were difficult to detach from the gold catalyst, necessitating an increase in the reaction temperature. Since high periodic transition metals such as gold and platinum are effective for hydrothiolation of alkenes and allenes, it is interesting to clarify whether iridium complexes, which belong to the same period as gold and platinum, could also catalyze alkene hydrothiolation. Through a detailed investigation of iridium ligands and reaction conditions, it was found that, in iridium systems, disulfide formation via oxidative coupling of thiols occurs preferentially over hydrothiolation reactions. This is likely due to steric hindrance around the iridium center, which inhibits alkene coordination to the iridium. Additionally, the hydrothiolation proceeding at low yields is believed to be a radical reaction involving electron transfer through the iridium complex. Full article

Glioblastoma is the most aggressive primary malignant tumor of the central nervous system in adults, with a poor prognosis and high resistance to conventional therapies. Platinum drugs like cisplatin are effective but limited by systemic toxicity, poor blood–brain barrier penetration, and resistance. Natural compounds are increasingly studied for their anticancer potential and ability to enhance existing therapies. Based on this rationale, we designed Pt(IV)Ac-GA, a novel platinum(IV) complex obtained by conjugating cisplatin with ganoderic acid A, a triterpenoid from Ganoderma lucidum known for anticancer and immunomodulatory effects. The compound was synthesized, structurally characterized, and showed high stability and favorable pharmacokinetics. In vitro, Pt(IV)Ac-GA strongly reduced the viability of U251 and T98G glioblastoma cells while sparing normal astrocytes. It triggered apoptosis, cell cycle arrest, impaired migration, and increased sensitivity to ferroptosis and mitochondrial dysfunction. These results highlight Pt(IV)Ac-GA as a promising candidate to overcome current limitations in glioblastoma treatment. Full article

A novel distilled alcoholic beverage was produced by fermenting yellow and red prickly pear (Opuntia ficus-indica) fruits with two Cypriot grape varieties (Mavro and Xynisteri), followed by traditional distillation. Two spirit variants (45% and 59% v/v alcohol) were prepared and assessed for physicochemical properties, antioxidant capacity, methanol, phenolic and flavonoid content, mineral composition, volatile profile, and sensory characteristics. Both spirits exhibited a pH of 3.83, total titratable acidity of 0.113% (expressed as citric acid), and methanol content between 0.38–1.85 g/hL of 100% v/v alcohol. Prickly pear addition enhanced the bioactive composition, with the yellow variant showing the highest flavonoid content (5.56 mg/L quercetin) compared to control zivania. Antioxidant activity (FRAP assay) ranged from 1.00 to 1.49 mg FeSO₄/L. Mineral analysis revealed elevated manganese, cobalt, and nickel in yellow (59% v/v) spirits, while red variants contained higher aluminum, platinum and magnesium. Volatile profiling showed increased ester and alcohol levels in 59% v/v beverages, with yellow spirits enriched in fruity esters (e.g., ethyl acetate). Sensory testing confirmed a greater consumer preference for prickly pear beverages, particularly yellow (59% v/v), which achieved a score of 9.7/10 for overall acceptability. These findings highlight the potential of prickly pear to contribute to the chemical composition and sensory complexity of grape-based distilled spirits. Full article

Miniaturization plays a critical role in modern microsystem engineering by enabling automation, reducing material consumption, and lowering operational costs. In electrochemical microsystems, thin-film electrodes are widely adopted due to their favorable surface-to-volume ratio and compatibility with scalable microfabrication processes. This study investigates the electrochemical performance, reliability, and reproducibility of titanium–platinum (Ti-Pt) thin-film microelectrodes patterned on both planar and non-planar glass substrates. The electrodes were fabricated using standard photolithography and physical vapor deposition (PVD) techniques, with curvature variation introduced to assess the effect of substrate topology on functional properties. Electrochemical characterization was conducted using classical cyclic voltammetry and impedance spectroscopy, with performance benchmarked against conventional platinum electrodes. The results show that Ti-Pt electrodes exhibit stable and repeatable behavior regardless of substrate curvature, with minor variations in impedance characteristics. These findings confirm the suitability of Ti-Pt microelectrodes for integration into complex lab-on-a-chip architectures, including those involving non-planar geometries. Full article

Fungal mastitis is rare but poses a significant problem for dairy farmers. It is often underestimated and under-researched, with most studies and treatments focusing on bacterial infections. Antibiotics are ineffective against fungi, and they exacerbate fungal mastitis. This study aimed to determine the antifungal properties of silver (Ag), gold (Au), copper (Cu), iron with a hydrophilic carbon coating (FeC), and platinum (Pt) nanoparticles (NPs) at five different concentrations, as well as their complexes, on the survival of fungal strains such as Pichia kudriavzevii, Wickerhamiella pararugosa, Saccharomyces cerevisiae, Cutaneotrichosporon mucoides, Wickerhamomyces anomalus, Coniochaeta hoffmannii, and Kluyveromyces marxianus. The strains’ susceptibility to 8 standard antifungals, along with MIC (minimal inhibitory concentration) and MFC (minimal fungicidal concentration) after NP treatment, was assessed. Clotrimazole and ketoconazole (10 µg) were most effective, while fluconazole (10 µg) and flucytosine (1 µg) showed the weakest activity. The AgCuNP complex demonstrated the strongest biocidal activity against all isolated strains, while FeCNPs and PtNPs showed very weak or no biocidal properties. The study’s results provide a basis for further in vivo research, indicating the great potential of nanoparticles in combating fungal mastitis, providing an innovative solution against infections caused by drug-resistant pathogens. Full article

Ionic liquid (IL) N-methyl-N′-1-(4-t-butylphenylphosphinyl)butylimidazolium bis(trifluoromethylsulphonyl) imide was used for the first time as an ion carrier in membrane systems to selectively transport Au(III), Pt(IV), and Pd(II) ions. Au(III), Pd(II), and Pt(IV) were transported from HCl solutions utilizing a polymer inclusion membrane (PIM) with cellulose triacetate as the support, o-nitrophenyl pentyl ether as the plasticizer, and ionic liquid as the mentioned ion carrier. The modifications of source and receiving aqueous phase compositions are examined. High selectivity for Au(III) using the ionic liquid in the membrane was achieved at elevated HCl concentrations (≥0.5 M). When a 0.010 M KI solution was used as the receiving phase and a membrane with the optimal composition was applied, the extraction of Au(III) ions reached a maximum recovery rate of 93%. Moreover, PIM studies showed that carrier molecules doped in the membrane creates complexes with the Au(III) ion with a molar ratio of 1:1. The extractability of Au(III) through PIMs exceeded that of other metal ions, with the selectivity of transported metal ions ranked as follows: Au(III) >> Pt(IV), Pd(II). The recovery factors for gold, platinum, and palladium ions after 6 h of transport were 94%, 8%, and 1%, respectively. Full article

Background: To battle the side effects of anticancer Pt(II) drug cisplatin, the development of photoactivatable and/or intracellular reduction-activatable Pt(IV) prodrugs has become a promising strategy. Methods: Herein, two novel Pt(IV) prodrugs, namely, cis,cis,trans-[Pt^IV(NH₃)₂(Cl)₂(OH)(probenecid)]) (SPP) and cis,cis,trans-[Pt^IV(NH₃)₂(Cl)₂(probenecid)₂] (DPP) bearing mono- and di-probenecid at the axial positions of oxoplatin have been synthesized via covalently linking of carboxylate group in probenecid, which is a well-established clinic drug by inhibiting organic anion transporter 1 (OAT1) to reduce cisplatin-induced nephrotoxicity, with the axial hydroxyl group(s) in oxoplatin. The promising cytotoxicity of SPP and DPP against MCF-7, T47D breast cancer cells and the MDA-MB-231 triple-negative breast cancer cells was evaluated, and the mechanism of action of the two Pt(IV) prodrugs was investigated by apoptosis assay and Western blot assay. Results: SPP exhibits a comparable cytotoxicity to cisplatin against MCF-7 and T47D breast cancer cells, while it shows 2.1-fold higher cytotoxicity than cisplatin against MDA-MB-231 cells. DPP was shown to be more cytotoxic than SPP, and exhibits 8.7-, 7.5-, and 2.3-fold higher cytotoxicity than cisplatin against MCF-7, T47D, and MDA-MB-231 cells, respectively. Apoptosis assays revealed a similar early-apoptotic cell death mechanism to cisplatin for both SPP and DPP. The enhanced cellular and nuclear uptake of DPP compared to cisplatin contributes to its promising anticancer efficacy. DPP can bind to OAT1 in cancer cells, which may synergistically enhance the cytotoxicity of the Pt(IV) anticancer prodrugs. Conclusions: The direct conjugation of probenecid to the axial positions of oxoplatin confers the resulting Pt(IV) prodrugs a multitargeting property, significantly promoting the cytotoxicity of the resulting Pt(IV) complexes. This finding provides a practical strategy for drug design and cancer treatment based on platinum complexes. Full article

Encouraged by the promising anticancer activity of a iodidogold(I)-N-heterocyclic carbene (NHC) complex with a 1,3-diethyl-4-anisyl-5-(4-chlorophenyl)imidazol-2-ylidene ligand system, a series of new gold(I), gold(III) and platinum(II) complexes coordinated to this ligand system were designed, prepared, and characterized using NMR spectroscopy and mass spectrometry methods. A preliminary anticancer screening of the complexes using four esophageal adenocarcinoma (EAC) cell lines showed promising activities for the cationic triphenylphosphino-NHC-gold(I) and bis-NHC-gold(I) complexes, accompanied by strong antiproliferative, colony-, and spheroid-forming inhibitory effects. The compounds were relatively less toxic to the normal esophageal cell line Het-1A and the monocyte cell line THP-1. Moreover, these compounds induced caspase 3/7 activity and downregulated anti-apoptotic proteins (Bcl-XL, Bcl-2, and Mcl-1) in EAC cells. Further, the cell cycle promoter cyclin D1 was suppressed by these NHC-gold(I) complexes. Finally, we observed strong reactive oxygen species (ROS) induction in EAC cells with NHC-gold(I) complexes 8 and 11. Full article

A new solvent extraction system for the removal of 4f ions (Ln³⁺) from water by use of chelating ligands (HLn, n = 5, 6, 7, and 8) composed of heterocyclic receptors and one β-dicarbonyl fragment is reported. The covalent attachment of a β-dicarbonyl unit to a saturated N-heterocycle with variable ring size resulted in a cooperative interaction within the receptor for Ln³⁺ transfer, which remarkably enhanced the efficiency of the process. The intramolecular cooperative effect was observed only in the ionic liquid (IL) solvent system, providing a several-fold increase in extraction performance for Ln³⁺ ions (La, Nd, Eu and Dy) over chloroform. Thus, it is not possible to confirm that an identical reaction mechanism operated in both liquid systems: IL or CHCl₃. The existence of neutral chelates of the type LnL₃ or anionic lanthanoid complexes [LnL₄⁻] in an ionic medium during the solvent extraction process applying various solvent systems has been established hitherto. Consequently, the Ln³⁺ ion was held by HLn molecules more rigidly in an IL medium ([C₁C_nim⁺]/[C₁C₄pyr⁺]/[C₁C₄pip⁺][Tf₂N⁻], n = 4, 6, 8, 10) than in chloroform, representing an important factor dominating the magnitude of the intramolecular cooperative effect of the chelating ligands for Ln³⁺ ions. The effect of the diluent’s chemical nature on the metal extraction and separation has been studied and discussed thoroughly. Furthermore, competitive solvent extraction and separation studies with various s-, p-, d-, and f-ions of the periodic table revealed that the magnitude of the intramolecular cooperative effect depends on the suitability between the metal ion size and the cavity size or flexibility of the HLn compounds. In addition, the solvent extraction process of 12 refractory metals and 8 platinum group metals with the synthesized chelating extractants is also investigated in different organic liquid media. Full article

Platinum(II)-based drugs, such as cisplatin, are commonly used to treat various types of cancer. However, their clinical use is limited due to a number of side effects and the development of resistance. To overcome these limitations, researchers have explored the development of platinum(IV) complexes as potential prodrugs that can be selectively activated under physiological conditions. In this study, we have incorporated synthetic analogs of vitamin E into the structure of platinum(IV) complexes to further improve their safety profile. The antioxidant properties of the compounds were evaluated using DPPH and CUPRAC assays, as well as lipid peroxidation inhibition models, revealing that incorporation of phenolic ligands confers pronounced antioxidant activity. Cytotoxicity was assessed towards cancer cell lines using the MTT assay, where the novel complexes showed significantly increased cytotoxic activity compared to cisplatin, while also demonstrating less toxicity toward normal fibroblast cells under the same in vitro conditions. These results suggest that the conjugation of antioxidant ligands to platinum(IV) scaffolds can modulate both redox processes and the biological activity of the resulting complexes. This proposed design strategy has the potential to create more effective platinum-based cancer treatments with enhanced biological characteristics. Full article

Platinum group metals (PGMs)—comprising platinum (Pt), palladium (Pd), rhodium (Rh), iridium (Ir), ruthenium (Ru), and osmium (Os)—are indispensable strategic materials for key industries, including automotive manufacturing, petrochemical engineering, and the new energy sector. Given the uneven global distribution of primary PGM reserves and the widening supply–demand gap, recovering PGMs from secondary sources—primarily metallurgical by-products and spent catalysts—has become a strategic priority. synergistic smelting, leveraging “multi-feedstock complementarity” and “multi-technology coupling,” offers an efficient approach to overcoming challenges associated with secondary resources, such as low grades, complex matrices, and refractory separation. This paper systematically reviews the technological evolution of synergistic smelting for PGMs recovery, focusing on three aspects: the characteristics and processing bottlenecks of PGMs-bearing secondary resources, the development trajectory of traditional metallurgical technologies, and innovative breakthroughs in microwave-assisted synergistic smelting. A comparative analysis between traditional and microwave-based technologies is conducted across four dimensions: resource adaptability, technical performance, environmental sustainability, and industrial maturity. Finally, the core challenges currently confronting microwave-assisted synergistic smelting and future directions for industrial demonstration are elaborated on. This study serves as a comprehensive reference for the efficient and sustainable recovery of PGMs, with significant implications for the circular economy and strategic resource security. Full article

This work presents the development of an automated and portable monitoring system for the point-of-need detection of tebuconazole and lambda-cyhalothrin. The system features nanoparticle/aptamer-modified electrochemical sensors that are integrated into a microfluidic chip based on polydimethylsiloxane (PDMS). More specifically, rapid and selective detection of both pesticides is achieved using target-specific aptamers immobilized on two-dimensional platinum nanoparticle films that serve as expanded nano-gapped electrodes to enhance sensor sensitivity. The effect of the device substrate (i.e., silicon versus flexible substrates) and measurement setup on biosensing performance has also been investigated. The final monitoring system is characterized by high sensitivity and selectivity in the cases of both target analytes and substrates. Τhe system features a limit of detection of 9.85 pM for tebuconazole, which is one of the lowest reported values in the literature; for lambda-cyhalothrin, it is worth noting that the results reported herein represent one of the few studies on an electrochemical aptamer-based sensor for this analyte, featuring a limit of detection of 48.5 pM. The system is also capable of selectively detecting both targets for complex cross-reactive sample matrices consisting of commercially available pesticides. Moreover, its use could be expanded to detect additional pollutants by functionalizing the biosensor surface with appropriate aptamers. Full article

Immunotherapy has significantly reshaped the management of malignant pleural mesothelioma (MPM), offering new therapeutic opportunities after decades in which platinum–pemetrexed chemotherapy represented the only systemic option. However, clinical benefit remains markedly heterogeneous, with outcomes strongly influenced by histologic subtype, patient characteristics, and real-world treatment conditions. Evidence from monotherapy trials has been inconsistent, whereas combination approaches—particularly nivolumab plus ipilimumab—have demonstrated improved survival compared with chemotherapy, mainly in non-epithelioid tumors. Nevertheless, real-world data consistently show lower efficacy and higher toxicity than registrational studies, especially among elderly and unselected populations. Recent translational work has highlighted the relevance of the tumor microenvironment and recurrent genomic alterations such as BAP1, NF2, and CDKN2A in shaping immune activity and potentially modulating response to immune checkpoint inhibitors. Transcriptomic signatures and circulating biomarkers—including soluble mesothelin-related peptide—have shown prognostic associations but no validated predictive value. Overall, current evidence suggests that sensitivity to immunotherapy in MPM arises from a complex interplay of genomic, immunologic, and clinical factors, and that no biomarker is yet suitable for guiding treatment decisions. Prospective studies integrating molecular and immune profiling will be essential to refine patient selection and advance toward a more rationally personalized use of immunotherapy Full article

Cancer ranks as a major cause of morbidity and mortality across the globe, notably in economically developed regions, and its incidence is predicted to rise in the coming decades. Metal-based compounds represent a particularly promising class of pharmaceuticals for the treatment of cancer. Following the success of platinum in cancer therapy, attention soon turned to other transition metals, particularly the platinum group metals such as ruthenium and palladium. Despite the high anticancer efficacy of many of its compounds, osmium remained one of the least investigated of these metals for a long time, partly due to concerns about its toxicity. However, there has been a recent resurgence in the preparation and evaluation of osmium complexes, which exhibit high structural variability and demonstrate promising anticancer activity. The present review aims to survey recent developments in this exciting field, focusing on osmium complexes of the non-arene type reported during the last decade. Full article

Apart from in hydrosilylation, platinum has traditionally played a limited role in homogeneous catalysis due to its high thermodynamic stability and lower intrinsic reactivity compared to other group 10 metals. However, the emergence of N-heterocyclic carbene (NHC) ligands has substantially broadened the catalytic profile of transition metals by enabling access to new mechanistic pathways and enhancing robustness under demanding conditions. This review summarizes advances in Pt–NHC catalysis reported between 2010 and 2025. These transformations encompass hydrosilylation of amides and CO₂, hydroboration and diboration, hydroamination, alkyne hydration, hydrogenation, selective alkyne dimerization, Suzuki–Miyaura coupling, arene C–H borylation, and cycloisomerization reactions, in which NHC ligands enhance bond activation, control regio- and stereoselectivity, and stabilize reactive Pt intermediates, including chiral architectures, enabling high enantioselectivity. Full article