Metal-based Compounds Research Articles

From Concept to Cure: The Road Ahead for Ruthenium-Based Anticancer Drugs.

The evolution of chemotherapy, especially the dawn of metal-based drugs, represents a transformative era in cancer treatment. From the serendipitous discovery of mustard gas's cytotoxic effects to the sophisticated development of targeted therapies, chemotherapy has significantly refined. Central to this progression is the incorporation of metal-based compounds, such as platinum (Pt), ruthenium (Ru), and gold (Au), which offer unique mechanisms of action, distinguishing them from organic therapeutics. Among these, Ru complexes, exemplified by BOLD-100 and TLD1433, have shown exceptional promise due to their selective activity, lower propensity for resistance, and the ability to target spescific cellular pathways. This paper explores the journey of such Ru candidates, focusing on the mechanisms, efficacy, and clinical potential of these Ru-based drugs, which stand at the forefront of current research, aiming to provide more targeted, less toxic, and highly effective cancer treatments.

Selenate oxyanion-intercalated NiFeOOH for stable water oxidation via lattice oxygen oxidation mechanism

Transition metal-based compounds can serve as pre-catalysts to obtain genuine oxygen evolution reaction (OER) electrocatalysts in the form of oxyhydroxides through electrochemical activation. However, the role and existence form of leached oxygen anions are still controversial. Herein, we selected iron selenite-wrapped hydrated nickel molybdate (denoted as NiMoO/FeSeO) as a pre-catalyst to study the oxyanion effect. It is surprising to find that SeO42− exists in the catalyst in the form of intercalation, which is different from previous studies that suggest that anions are doped with residual elements after electrochemical activation, or adsorbed on the catalyst surface. The experiment and theoretical calculations show that the existence of SeO42− intercalation effectively adjusts the electronic structure of NiFeOOH, promotes intramolecular electron transfer and O–O release, and thus lowers the reaction energy barrier. As expected, the synthesized NiFeOOH-SeO only needs 202 and 285 mV to attain 100 and 1000 mA cm−2 in 1 M KOH. Further, the anion exchange membrane water electrolyzer (AEMWE) consisting of NiFeOOH-SeO anode and Pt/C cathode can reach 1 A cm−2 at 1.70 V and no significant attenuation within 300 h. Our findings provide insights into the mechanism, by which the intercalated oxyanions enhance the OER performance of NiFeOOH, thereby facilitating large-scale hydrogen production through AEMWE.

Chitosan-Zinc-Ligated Hydroxychloroquine: Molecular Docking, Synthesis, Characterization, and Trypanocidal Activity against Trypanosoma evansi

The existing treatments against Trypanosoma evansi are faced with several drawbacks, such as limited drug options, resistance, the relapse of infection, toxicity, etc., which emphasizes the necessity for new alternatives. We synthesized novel metal-based antiparasitic compounds using chitosan, hydroxychloroquine (HC), and ZnO nanoparticles (NPs) and characterized them for size, morphology, chemical interactions, etc. Molecular docking and protein interaction studies were performed in silico to investigate the inhibitory effects of HC, zinc-ligated hydroxychloroquine (HCZnONPs), and chitosan-zinc-ligated hydroxychloroquine (CsHCZnONPs) for two key proteins, i.e., heat shock protein 90 (Hsp90) and trypanothione reductase associated with T. evansi. In vitro trypanocidal activity and the uptake of zinc ions by T. evansi parasites were observed. The formulation was successfully synthesized, as indicated by its size, stability, morphology, elemental analysis, and functional groups. CsHCZnO nanoparticles strongly inhibit both Hsp90 and trypanothione reductase proteins. The inhibition of Hsp90 by these nanoparticles is even stronger than that of trypanothione reductase when compared to HC and HCZnONPs. This suggests that the presence of polymer chitosan enhances the nanoparticles’ effectiveness against the parasite. For the first time, CsHCZnO nanoparticles exhibited trypanocidal activity against T. evansi, with complete growth inhibition being observed at various concentrations after 72 h of treatment. Fluorescent microscopy using FluoZin-3 on T. evansi culture confirmed the presence of zinc on the surface of parasites. This innovative approach has shown promising results in the quest to develop improved antiparasitic compounds against T. evansi with enhanced effectiveness and safety, highlighting their potential as therapeutic agents against trypanosomiasis.

STUDY OF COPPER COMPLEXES [Cu(LCF3)2] AND [Cu(Lcur)2]H2O AS RADIOPROTECTIVE COMPOUNDS

One of the first and direct signs of the impact of ionizing radiation (IR) on a cell is the destabilization of chromosomes. Radiation-induced damage to the karyotype is an important indicator both for biological indication of the severity of radiation injuries and for predicting the development of long-term adverse effects of IR. The search for new, effective radioprotective compounds is a priority task of modern radiobiology. In this area, metal-based compounds with high antioxidant activity are of particular interest. The purpose of this work is to determine the possible radioprotective properties of Cu(II) complexes, [Сu(LCF3)2] and [Cu(Lcur)2]H2O, supported by the anions of the β-diketone ligands 1,1,1,5,5,5-hexafluoro-2,4-pentanedione (HLCF3) and 1,7-bis(4-hydroxy-3-methoxyphenyl)-1,6-heptadiene-3,5-dione or curcumin (HLcur). In this research work we determined survival, life expectancy and cytogenetic parameters: mitotic index, chromosome aberrations and % of polyploid cells in the bone marrow cells of the femur (count in 1000 cells in each preparation). Group I included intact animals; Group II consisted of animals exposed to the radioisotope technetium; Group III consisted of animals that were intraperitoneally injected with copper complex [Cu(LCF3)2] at a dose of 50 mg/kg in a volume of 2 mL one hour before the administration of the Tc isotope (“irradiation + copper compound [Cu(LCF3)2]); Group IV included animals that received the compound [Cu(Lcur)2]H2O before irradiation. The groups with the injection of [Cu(LCF3)2] complex had the highest survival. In terms of chromosomal aberrations and number of polyploid cells, as indicators, a significant difference was found in those irradiated compared with the “irradiation + [Cu(LCF3)2]” group (both after 15 and after 30 days), which indicates the radioprotective property of the compound. In terms of the mitotic index, a tendency towards normalization was noted after 15 days and a significant difference between Groups 2 and 3 by the end of the study (after 30 days), which also proves the beneficial effect of this compound. Analysis of survival and changes in cytogenetic parameters multiregression analysis using both complexes confirms the greatest efficiency of the [Cu(LCF3)2] complex with respect to [Cu(Lcur)2]H2O, because when using [Cu(Lcur)2]H2O in Group IV and comparing it with “pure irradiation” only a tendency toward normalization of cytogenetic parameters was observed. Multiregression analysis of cytogenetic parameters also confirmed the highest efficiency of the [Cu(LCF3)2] compound in comparison with [Cu(Lcur)2]H2O. The results of the research indicate the need to continue work in the direction of searching for agents that have a therapeutic effect in radiation injuries.

Organoselenium transition metal complexes as promising candidates in medicinearea.

The medicinal properties of transition metal complexes are greatly influenced by the nature and physico-chemical features of the ligand present in the complex structure. Due to the unique biological properties of the organoselenium compounds reflected in the variety of pharmacological activities (such as antioxidative, antiviral, antimicrobial and anticancer), the last years have brought increased interest for their use as a ligands compounds in the design and syntheses of range of transition metal-based coordination compounds that have been explored as antitumor and antimicrobial agents. Our aim in this review is to provide the overview of an recent development of the transition metal complexes bearing organoselenium ligands in the structure that could be promising choice for the treatment of various diseases, particularly cancer and infective diseases. For this purpose, the complexes of Co, Ni, Cu, Zn, Ru, Pd, Pt, Au and Sn as the most explored examples will be included and discussed.

Exploring the Biological Effects of Anti-Diabetic Vanadium Compounds in the Liver, Heart and Brain.

The prevalence of diabetes mellitus and diabetes-related complications is rapidly increasing worldwide, placing a substantial financial burden on healthcare systems. Approximately 537 million adults are currently diagnosed with type 1 or type 2 diabetes globally. However, interestingly, the increasing morbidity rate is primarily influenced by the effects of long-term hyperglycemia on vital organs such as the brain, the liver and the heart rather than the ability of the body to use glucose effectively. This can be attributed to the summation of the detrimental effects of excessive glucose on major vascular systems and the harmful side effects attributed to the current treatment associated with managing the disease. These drugs have been implicated in the onset and progression of cardiovascular disease, hepatocyte injury and cognitive dysfunction, thereby warranting extensive research into alternative treatment strategies. Literature has shown significant progress in utilizing metal-based compounds, specifically those containing transition metals such as zinc, magnesium and vanadium, in managing hyperglycaemia. Amongst these metals, research carried out on vanadium reflected the most promising anti-diabetic efficacy in cell culture and animal studies. This was attributed to the ability to improve glucose management in the bloodstream by enhancing its uptake and metabolism in the kidney, brain, skeletal muscle, heart and liver. Despite this, organic vanadium was considered toxic due to its accumulative characteristics. To alleviate vanadium's toxic nature while subsequently manipulating its therapeutic properties, vanadium complexes were synthesized using either vanadate or vanadyl as a base compound. This review attempts to evaluate organic vanadium salts' therapeutic and toxic effects, highlight vanadium complexes' research and provide insight into the novel dioxidovanadium complex synthesized in our laboratory to alleviate hyperglycaemia-associated macrovascular complications in the brain, heart and liver.

Metal-based compounds: Synthesis and characterization of new thiazole-based iridium and palladium complexes with potential anticancer and other biological activities

Thiazoles and their derivatives are one of the most active classes of compounds known for their wide spectrum of bioactivity. Metal complexes, based on them, show antitumor potential that is attractive for investigations. Herein, we report 6 new biologically active thiazole-based complexes have been synthesized. The iridium- and palladium-based coordination compounds obtained by the precipitation method were characterized using elemental analysis (EA), Fourier-transform infrared spectroscopy (FTIR), magnetic measurements, thermogravimetric analysis coupled with mass spectrometry (TGA-MS), and scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDX). Spectroscopic data helped to propose the formulas of the complexes and indicated that all ligands acted in a monodentate manner. Water molecules were identified by thermal analysis and FTIR spectroscopy. Mathematical analysis and evaluation of thermodynamic parameters including entropy (ΔS), Gibbs free energy (ΔG), and activation energy (E) were performed using the Coats–Redfern method for all complexes. The biological potential (anticancer, antibacterial, and antifungal properties) of compounds was analyzed by biological evaluation studies. Investigated CT-DNA studies revealed that the prepared compounds were intercalatively bound to the DNA. Cytotoxicity analyses showed that complexation with Ir(III) increased the toxicity of L2 towards both tested cell lines (LN-229 and MDA-MB-231), while complexation of L3 with Pd(II) significantly increased cytotoxic activity against LN-229. Due to this, the further biological studies, such as apoptosis/necrosis detection, cell cycle analysis and JC-1 fluorescence measurements were performed on this pair of compounds.

Novel gold-based complex GC7 suppresses cancer cell proliferation via impacting energy metabolism mediated by mitochondria

Due to their pivotal roles in regulating energy metabolism and apoptosis, mitochondria in cancer cells have been considered a vulnerable and feasible target. Many anticancer agents, e.g., metal-based compounds, are found to target and disturb mitochondria primarily, which may lead to the disturbance of energy metabolism and, more importantly, the initiation of apoptosis. In this work, a gold-based complex 7 (GC7) was synthesized and evaluated in a series of different cancer cell lines. The anticancer efficacies of GC7 on cell viability, apoptosis, and colony formation were determined. Cellular thioredoxin reductase (TrxR) activity, oxygen consumption rate (OCR), glucose uptake, and lactate production following GC7 treatment were evaluated and analyzed. The Jeko-1 and A549 xenograft models were used to assess GC7’s tumor-suppressing effects. The results showed that GC7 possessed a broad-spectrum anticancer effect, with IC50 values ranging from 0.43 to 1.2 μM in multiple cancer cell lines, which was more potent than gold-based auranofin (∼2–6 folds). GC7 (0.3 and 1 μM) efficiently induced apoptosis of Jeko-1, A549, and HCT116 cells, and it suppressed the sphere formation of cancer stem cells GSC11 and GSC23 cells at 0.1 μM, and it completely eliminated colony at 0.3 μM. The preliminary mechanistic study showed that GC7 inhibited cellular TrxR activity, suppressed mitochondrial OCR, reduced mitochondrial membrane potential (MMP), decreased glucose uptake, and possibly suppressed glycolysis to reduce lactate production. GC7 was predicted to have a similar yet slightly different pharmacokinetic profile as auranofin. Finally, GC7 (20 mg/kg, oral, 5/week, or 3 mg/kg, IP, 3/week) significantly inhibited tumor growth. In conclusion, GC7 showed great potential in suppressing cancer cell proliferation, probably via inhibiting TrxR and impacting mitochondria-mediated energy metabolism.

Emerging Bismuth-Based Materials: From Fundamentals to Energy Applications

In practical applications, supercapacitors, renewable and efficient techniques of energy storage and conversion, are commonly assembled into supercapacitor, which has been attracting growing interest in energy applications for the past decade. To achieve this decisive task, it is essential that electrode materials with high energy density and electrochemical stability are explored for environment-friendly and economical utilization. Numerous studies have been conducted on metal-based compounds and their relative materials; including bismuth-based materials and their composites are promising because of their redox behavior, charge storage capacity, environmental friendliness, and increasing research toward their application in energy for solar water splitting and supercapacitor. Herein, we outline bismuth materials and their composites, as investigated by our research, highlight their applications in energy, and, more importantly, focus on the study of their performance in photoelectrochemical hydrogen production and supercapacitive electrochemical techniques. We also present a summary of energy storage devices and their mechanisms, as well as other types of non-bismuth-based electrode materials available in the market. In addition, the major challenges and future perspectives of bismuth-based composites for energy purposes are addressed.

Comprehensive review of metal-based coordination compounds in cancer therapy: from design to biochemical reactivity

Abstract Throughout history, metal-based coordination compounds have been used for medical purposes, including the treatment of various illnesses like cancer. Since the discovery of cisplatin in 1965, many other metal coordinating complexes have been developed and evaluated, involving metals such as platinum, iron, zinc, ruthenium, gold, silver, titanium, and copper. The goal behind these efforts is to create effective and safe medications. At the moment, there are a lot of studies talking about the use of cytostatic metal complexes, mainly on promising platinum- and non-platinum-based drugs in both preclinical and clinical trials. However, there is a lack of recent comprehensive studies that cover both the chemical and biological aspects of metal-based coordinating molecules in the context of cancer therapy. This review aims to provide a thorough analysis of the coordination chemistry of existing and innovative cytostatic substances. It will include a description of their design and synthesis, as well as a summary of the biochemical reactivity and physicochemical features of potential metal-containing complexes.

Investigation into the supplementation of a ferric sillen core-linked polymer on the health and physiological performance of broiler chickens

Poultry is a ubiquitous and highly sought-after protein source valued for its accessibility, notable protein content, and lack of religious constraints. However, the demand for poultry has resulted in a surge in intensive production practices. The transition from subsistence agricultural practices to intensive food production resulted in the widespread adoption of antibiotics for both therapeutic and economic purposes. These interventions were intended to enhance meat yield, promote bird health, and enhance cost-effectiveness of production. However, this inadvertently contributed to the rise of antimicrobial resistance (AMR). Therefore, the need to explore alternative approaches to mitigate the problems associated with AMR has become increasingly pressing. In response, metal-based compounds have emerged as a promising substitute to conventional antibiotics. In this study, the effects of a water soluble metallo-antimicrobial supplement, ferric sillen core-linked polymer (FSCLP), on body weight gain, feed conversion, water intake, volatile fatty acid (VFA) production, cecal microbiome and intestinal morphology in broilers was examined. The findings of this study suggested that the addition of the FSCLP resulted in better bird performance, even during a period of heat stress. Volatile fatty acids (VFA) analysis of cecal contents indicated that there were significantly higher levels (p < 0.05) of butyric and valeric acids. Cecal microbiome analysis confirmed significantly lower abundance (p < 0.05) of Proteobacteria (e.g., E. coli) and a significantly greater abundance of VFA-producing bacteria such as Intestinimonas butyriciproducens, Blautia and Lachnospiraceae. The intestinal morphology data showed supplementation with the FSCLP at 80 ppm resulted in a significantly higher (p < 0.05) villus height of the jejunum.This study emphasises the potential of FSCLP as a feasible solution to the issues faced by AMR in chicken production, providing insights into its beneficial impacts on performance, microbial composition, and intestinal health.

Theoretical and experimental demonstration of mononuclear Ni(II) and dinuclear Ni(III) complexes concerning their catalytic activity, DNA/ protein binding efficacy

The successful use of metal complexes in enzyme catalysis and biomedical applications boosts researchers to develop more and more metal-based compounds to inspect their said applications.In the present work one novel mononuclear Ni(II) [Ni(L1)2] (1) and one di nuclear Ni(III) complexes [Ni(L2)2(N3)2] (2) have been developed by utilizing N2O donor Schiff base ligand HL1 and N2O2 donor Schiff base ligand H2L2 respectively. The single crystal data analysis reveals that in complex 1 two deprotonated ligands coordinate to the Ni(II) forming a distorted octahedral geometry. The asymmetric unit of complex 2 comprises one deprotonated ligand (both the protons of phenolic –OH group were deprotonated), one azide anion, and one Ni(III). Two Ni(III) centers are connected via phenoxide bridging. Followed by the structural analysis the UV spectroscopic study is performed to understand the catecholase-like activity of the developed complexes by using 3,5-di-tertbutyl catechol (3,5-DTBC). The calculated turnover numbers (Kcat) for both complexes disclose the fact that complex2 is more susceptible to this catalytic process than 1. During the catalysis process, the production of Ni(II) in the case of complex2is favorable and this is the main factor to show its higher susceptibilitytowards the catalytic process. The biomedical applicability in terms of anticancer and antibacterial of complexes 1 and 2 is assessed by evaluating their interaction ability with DNA and HSA with the help of several spectroscopic approaches. The remarkably high complex-macromolecules binding constant values, obtained from electronic titration approve the binding efficacy of the target complexes (order ∼ 105). But if a tiny comparison is done then it is seen that complex 2 shows better DNA and HSA binding efficacy. The theoretical approach using molecular docking study fully validates the experimental findings.

Cell Metabolomics to Guide the Design of Metal-Based Compounds

Despite the increasing interest in the development of novel metal-based compounds for cancer treatment, these molecules are currently poorly characterized in mechanistic terms, due to their multiple macromolecular targets inside the cells. In this review, we show how 1H NMR metabolomics provides a powerful tool to investigate the metabolic perturbations induced by metal-compounds in cells. The chemical identity and concentration of metabolites detected in cell lysates and their respective growth media by NMR can be viewed as a global fingerprint that describes the response to drug treatment. In this framework, the applications of NMR-based metabolomics to study cellular effects induced by the treatment of cells with anticancer metal-based compounds are comprehensively reviewed.

Anti-Inflammatory and Antithrombotic Potential of Metal-Based Complexes and Porphyrins

Inflammation and thrombosis are implicated in several chronic disorders. Recent studies have outlined the way in which several compounds can offer protection against inflammation. Within this comprehensive review the so-far reported anti-inflammatory health-promoting effects of several metal-based complexes, both in vitro and in vivo, are thoroughly presented. These metal-based compounds usually interfere with various biochemical processes associated with the inflammatory response and thrombus formation and become capable of inhibiting these biochemical pathways with proposed health benefits. Emphasis is given to the multifaceted actions of metal-based complexes that have exhibited potent anti-inflammatory and antithrombotic activities against the inflammatory mediator, platelet-activating factor (PAF), and its thrombo-inflammatory signaling, as well as on their anti-platelet and antitumor health promoting properties. Furthermore, the enhancement of the anti-inflammatory potency of well-established bioactive compounds by their incorporation as ligands in several metal-based complexes is discussed. Metal-based complexes bearing natural anti-inflammatory bioactives are also outlined. Characteristic examples of both free and metal-based porphyrins are explored. These compounds are recognized to have anti-inflammatory and antithrombotic assets, in addition to other pleiotropic advantages including antibacterial or anticancer actions. Additionally, applications of metal complexes in various models of inflammatory and thrombotic complications are demonstrated. The combined results of this study show that further research is required towards the preparation of several metal-based complexes with improved pharmacological profiles. Finally, restrictions on the application of these metal-based compounds are also covered, along with their prospects for the future and the need for additional study in order to improve their efficacy and safety.

Necroptosis induced by ruthenium (II) complexes as mitochondrial disruptors

Inducing necroptosis in cancer cells has emerged as an effective strategy to overcome drug resistance. However, while organic small molecules have been extensively studied for this purpose, metal-based compounds have received relatively little attention as triggers of necroptosis. The development of ruthenium (II) hybrid compounds, particularly those containing triazene (Ru-TRZ), highlights a novel avenue for modulating necroptotic cell death. Here we show that incorporating a methyltriazene moiety, a known alkylating warhead, confers superior mitochondrial-targeting properties and enhances cell death compared to amide-containing counterparts. Ru-hybrid TRZ2 exhibits also antitumor efficacy against in vivo drug-resistant cancer cells. Mechanistically, we demonstrate that Ru-TRZ hybrids induce apoptosis. In addition, by activating downstream RIPK3-driven cell death, TRZ2 proficiently restrains normal mitochondrial function and activity, leading to cancer cell necroptosis. Finally, TRZ2 synergizes anti-proliferative activity and cell death effects induced by conventional drugs. In conclusion, Ru-TRZ2 stands as a promising ruthenium-based chemotherapeutic agent inducing necroptosis in drug resistant cancer cells.

Retaining the self-released chalcogenate at reconstructed cobalt sites by self-transformed carbonate regulation for boosted oxygen evolution

The in-situ generated oxyanions at electrochemically reconstructed catalysts from metal-based non-oxide compounds have been proven to significantly accelerate oxygen evolution reaction (OER) kinetics. However, it remains a challenge to retain these self-released oxyanions at reconstructed catalysts, hindering its utilization as a tool to develop efficient OER catalysts. Here, we demonstrate a versatile self-transformed carbonate regulation strategy to efficiently retain the self-released chalcogenate at Co oxyhydroxides reconstructed from carbon-incorporated Co selenides under OER conditions. These self-transformed CO32− can induce electron accumulation and narrow d bond at Co sites to facilitate the Co 3d–O 2p orbital hybridization between Co sites and SeOx2− for enhanced SeOx2− retention, which can accelerate the rate-limiting step for *OOH formation during OER. Relative to CoOOH-SeOx2− with limited SeOx2− residues, CoOOH-CO32−/SeOx2− with elevated SeOx2− retention by CO32− regulation exhibited a 5.6-fold increase in current density and a remarkable lower Tafel slope towards OER. This strategy paves a rational avenue to design efficient catalysts for electrooxidation reactions through finely regulating self-released oxyanions at reconstructed structures.

Impact of Nanoparticle-Based TiO2 Surfaces on Norovirus Capsids and Genome Integrity.

Human noroviruses (HuNoVs) are among the main causes of acute gastroenteritis worldwide. HuNoVs can survive for several days up to weeks at room temperature in the environment, on food, and on food handling and processing surfaces. As a result, this could lead to viral spread through the ingestion of food in contact with contaminated surfaces. The development of stable surface materials with antiviral activity might be useful to reduce viral outbreaks. Metal-based compounds, including photoactivated titanium nanoparticles (TiO2 NPs), are known for their antiviral activity. In this study, we tested the impact of 2000 µg/mL TiO2 NPs, with or without UV activation, on HuNoV GII and murine norovirus. Their recovery rates were reduced by 99.6%. We also evaluated a new TiO2 NP-coating process on a polystyrene surface. This process provided a homogenous coated surface with TiO2 NPs ranging between 5 nm and 15 nm. Without photoactivation, this TiO2 NP-coated polystyrene surface reduced the recovery rates of intact HuNoV GII by more than 94%. When a capsid integrity treatment with PtCl4 or a longer reverse transcription polymerase chain detection approach was used to evaluate virus integrity following contact with the TiO2 NP-coated polystyrene, the HuNoV GII recovery yield reduction varied between 97 and 100%. These results support the hypothesis that TiO2 NP-coated surfaces have the potential to prevent viral transmission associated with contaminated food surfaces.

Novel antimony-based antimicrobial drug targets membranes of Gram-positive and Gram-negative bacterial pathogens.

Antibiotic resistance presents a critical global public health crisis that threatens our ability to combat bacterial infections. In light of the declining efficacy of traditional antibiotics, the use of alternative solutions, such as metal-based antimicrobial compounds, has gained renewed interest. Based on the previously synthesized innovative organoantimony(V) compounds, we selected and further characterized the antibacterial efficacy of five of them against three important Gram-positive and Gram-negative bacterial pathogens. Among these compounds, SbPh4ACO showed broad-spectrum bactericidal activity, with membrane-disrupting effects against all three pathogens. Furthermore, we revealed the synergistic potential of SbPh4ACO when combined with antibiotics, such as cefoxitin, at concentrations that exert no cytotoxic effects tested on three mammalian cell lines. This study offers the first report on the mechanisms of action of novel antimony-based antimicrobial and presents the therapeutic potential of SbPh4ACO in combating both Gram-positive and Gram-negative bacterial pathogens while enhancing the efficacy of existing antibiotics.

Time-series analysis of rhenium(I) organometallic covalent binding to a model protein for drug development.

Metal-based complexes with their unique chemical properties, including multiple oxidation states, radio-nuclear capabilities and various coordination geometries yield value as potential pharmaceuticals. Understanding the interactions between metals and biological systems will prove key for site-specific coordination of new metal-based lead compounds. This study merges the concepts of target coordination with fragment-based drug methodologies, supported by varying the anomalous scattering of rhenium along with infrared spectroscopy, and has identified rhenium metal sites bound covalently with two amino acid types within the model protein. A time-based series of lysozyme-rhenium-imidazole (HEWL-Re-Imi) crystals was analysed systematically over a span of 38 weeks. The main rhenium covalent coordination is observed at His15, Asp101 and Asp119. Weak (i.e. noncovalent) interactions are observed at other aspartic, asparagine, proline, tyrosine and tryptophan side chains. Detailed bond distance comparisons, including precision estimates, are reported, utilizing the diffraction precision index supplemented with small-molecule data from the Cambridge Structural Database. Key findings include changes in the protein structure induced at the rhenium metal binding site, not observed in similar metal-free structures. The binding sites are typically found along the solvent-channel-accessible protein surface. The three primary covalent metal binding sites are consistent throughout the time series, whereas binding to neighbouring amino acid residues changes through the time series. Co-crystallization was used, consistently yielding crystals four days after setup. After crystal formation, soaking of the compound into the crystal over 38 weeks is continued and explains these structural adjustments. It is the covalent bond stability at the three sites, their proximity to the solvent channel and the movement of residues to accommodate the metal that are important, and may prove useful for future radiopharmaceutical development including target modification.

Characterization and Flame-Retardant Properties of Cobalt-Coordinated Cyclic Phosphonitrile in Thermoplastic Polyurethane Composites.

Halogen-free organophosphorus flame retardants have promising application prospects due to their excellent safety and environmental protection properties. A cobalt-coordinated cyclic phosphonitrile flame retardant (Co@CPA) was synthesized via a hydrothermal method using hexachlorocyclotriphosphonitrile (HCCP), 5-amino-tetrazolium (5-AT), and cobalt nitrate hexahydrate (Co(NO3)2∙6H2O) as starting materials. The structure was characterized using Fourier transform infrared (FTIR), nuclear magnetic resonance spectroscopy (1H-NMR), scanning electron microscopy (SEM), and thermogravimetric analysis (TGA). Thermoplastic polyurethane (TPU) composites were prepared by incorporating 10-(2,5-dihydroxyphenyl)-9,10-dihydro-9-oxa-10-phosphame-10-oxide (ODOPB), Co@CPA, and silicon dioxide (SiO2) via melt blending. The flame-retardant performance and thermal stability of the TPU composites were evaluated through limiting oxygen index (LOI), vertical combustion (UL-94), TG, and cone calorimetric (CCT) tests. SEM and Raman spectroscopy were used to analyze the surface morphology and structure of the residual carbon. A synergistic flame-retardant effect of ODOPB and Co@CPA was observed, with the most effective flame retardancy achieved at a TPU:ODOPB:Co@CPA:SiO2 ratio of 75:16:8:1. This composition exhibited an LOI value of 26.5% and achieved a V-0 rating in the UL-94 test. Furthermore, compared to pure TPU, the composite showed reductions in total heat release, CO production, and CO2 production by 6.6%, 39.4%, and 48.9%, respectively. Our research findings suggest that Co@CPA demonstrates outstanding performance, with potential for further expansion in application areas. Different metal-based cyclic phosphonitrile compounds are significant in enriching phosphorus-based fine chemicals.