2026 · Dalton Transactions · Royal Society of Chemistry · added 2026-04-20
We report the facile synthesis of new gold(I) carbene complexes based on a mesoionic cobaltocenylidene metallocarbene via a fluorinative desilylation reaction. The carbene has been characterize Show more
We report the facile synthesis of new gold(I) carbene complexes based on a mesoionic cobaltocenylidene metallocarbene via a fluorinative desilylation reaction. The carbene has been characterized by a variety of spectroscopic methods, revealing that it has the highest HEP value reported for a MIC so far, suggesting that the carbene is highly electron donating. The properties of the new class of metallo-mesoionic carbenes is further investigated, revealing also exceptionally low TEP values. Electrochemical studies also suggest the cobaltocenium moiety to be further reducible. In addition, the cell growth inhibitory effects of the new metallocarbene complexes were explored in cancer cells and bacteria. The combination of electrochemical activity, exceptional electron donating properties and their putative application in medicinal chemistry makes these new metallo-MICs a highly interesting new class of ligands. Show less
Atomically precise Au25 nanoclusters are ideal catalyst models for unraveling the nanozyme structure-activity relationship due to their well-defined structures and tunable electronic proper Show more
Atomically precise Au25 nanoclusters are ideal catalyst models for unraveling the nanozyme structure-activity relationship due to their well-defined structures and tunable electronic properties. Herein, ab initio molecular dynamics (AIMD) simulations combined with density functional theory (DFT) calculations were employed to systematically investigate the ligand removal behavior and peroxidase (POD)-like catalytic activity of Au25 nanoclusters modified with phosphine (PR), thiol (SR), alkynyl (C≡CR), and N-heterocyclic carbene (NHC) ligands. Constrained AIMD (cAIMD) simulations revealed that all clusters preferentially remove halogen ligands (Cl/Br) with free energy barriers below 0.25 eV, while NHC and phosphine ligands exhibit stronger binding stability with the Au core. The exposed low-coordination gold sites upon halogen removal display excellent POD-like activity, wherein the second *OH reduction (or the second TMB oxidation) is determined to be the rate-determining step (RDS). Among them, [Au25(NHC)10(Br)6]2+-top (removal of Br at the top coordination site) exhibits the most optimal activity with a moderate RDS barrier (0.83 eV) owing to its isolated active site and higher d-band center that balance *OH adsorption and the catalytic activity. This study clarifies the structure-activity relationship of atomically precise Au25 nanoclusters in the peroxidase-like catalysis, providing a quantitative basis for high-efficiency Au-based nanozyme design. Show less
The first comprehensive study of a series of seven mesoionic tetrazolylidene gold(I) chloride complexes (1-7) featuring a range of alkyl and aryl substituents (Me, t-Bu, iPr, Ph, Show more
The first comprehensive study of a series of seven mesoionic tetrazolylidene gold(I) chloride complexes (1-7) featuring a range of alkyl and aryl substituents (Me, t-Bu, iPr, Ph, Tol, Dipp, Mes) is reported. Three synthetic pathways enabling access to scarcely explored abnormal 1,3-disubstituted tetrazolium ligand precursors (L1-L7) have been established. All complexes are characterized by NMR spectroscopy, mass spectrometry, and elemental analysis, confirming their composition and purity. Single-crystal X-ray crystallography of six gold(I) complexes (1-6) reveals nearly linear coordination (176.49(11)-179.0(2)°) at the gold(I) center and a distinct geometric arrangement across the series. NMR stability studies with model nucleophiles L-cysteine (Cys) and glutathione (GSH) support the structural findings, demonstrating rapid and complete reaction of complexes 1-7 with thiols, as confirmed by 1H NMR and ESI-MS. The antiproliferative activity of the obtained complexes (1-7) and selected precursors (L2, L3, L5, L7) has been evaluated using MTT assays against human A2780 (ovarian) and A549 (lung) cancer cell lines, alongside noncancerous VERO E6 kidney cells for comparison. Most of the complexes display high selectivity indices (SIA2780 = 63.2-86.7) and potent antiproliferative effects in the low submicromolar range against A2780, outperforming cisplatin and matching the activity of auranofin. Overall, the results presented here demonstrate the potential of gold(I) tetrazolylidene-based complexes for medicinal applications. Show less
Colorectal cancer (CRC) remains a major global health challenge, in which chronic inflammation and redox dysregulation are key drivers of tumor progression. Here, we report a rationally designed famil Show more
Colorectal cancer (CRC) remains a major global health challenge, in which chronic inflammation and redox dysregulation are key drivers of tumor progression. Here, we report a rationally designed family of NSAID-derived alkyne ligands coordinated to JohnPhos-gold(I) fragments, affording eight new alkynyl gold(I) derivatives. Complexes based on naproxen, ibuprofen, and salicylic acid derivatives display potent antiproliferative activity against Caco-2/TC7 colon cancer cells, outperforming oxaliplatin and being comparable to auranofin, while showing markedly reduced cytotoxicity in breast cancer lines and nonmalignant cells, thus indicating promising selectivity. Mechanistic studies revealed that the most active complex, [Au(L1)JP] (1), which contains a naproxen-derived alkyne, inhibits thioredoxin reductase (TrxR), triggers ROS overproduction, disrupts mitochondrial membrane potential, and induces G1-phase arrest while only marginally increasing apoptosis. This suggests the involvement of additional forms of cell death or cytostatic effects. Additionally, complex 1 selectively inhibits the enzyme cyclooxygenase-2 (COX-2) over COX-1 and reduces IL-8 expression without affecting PTGS2 transcription, highlighting a post-transcriptional anti-inflammatory action. These results support NSAID-derived alkynyl gold(I) complexes as promising multitarget agents for colorectal cancer intervention, combining disruption and COX-2 modulation. Show less
Hybrid phosphines with anionic hard donor functions can be used to create an adaptable ligand environment for soft late transition metals. Herein, we show that the change of coordination of a Show more
Hybrid phosphines with anionic hard donor functions can be used to create an adaptable ligand environment for soft late transition metals. Herein, we show that the change of coordination of a diphosphine–phosphinic acid (P3OOH) in response to acid–base interactions or hydrogen bonding results in structural transformations of a disilver complex [Ag2(P3OO)2] (1) to give solvated and protonated derivatives [Ag2(P3OOH)2]2+ (2) and [Ag3(P3OO)3H]+ (3), accompanied by the alteration of the quantum yield of the solid-state photoluminescence from 0.06 up to 0.69. The related diphosphine–phosphide oxide complexes [M2(P3O)2] (M = Ag, Au) are oxidized to phosphinate compounds 2 and non-luminescent [Au2(P3OO)2H]+ (5) in the presence of triflic acid. Alternatively, [Au2(P3O)2] readily accommodates an additional gold(I) ion to yield a trinuclear cluster [Au3(P3O)2]+ (6), which is brightly sky-blue phosphorescent in the crystalline state (Φem = 0.76). The phosphide oxide group −PO in 6 is stable towards oxidation under acidic conditions in solution but undergoes protonation that results in two orders of magnitude (>170-fold) increase of the emission intensity. Complex 6 acts as a guest in the crystalline matrix of 5 due to their structural similarity and affords solid solutions with bright luminescence at a doping content of 1–2%.
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Challenges in pancreatic cancer treatment primarily arise from chemotherapy resistance, cancer cell metastasis, and frequent late-stage diagnoses. These issues significantly compromise the effectivene Show more
Challenges in pancreatic cancer treatment primarily arise from chemotherapy resistance, cancer cell metastasis, and frequent late-stage diagnoses. These issues significantly compromise the effectiveness of standard treatments and highlight the urgent need for targeted approaches. In this context, we explored the anticancer potential of bis-quaternary ammonium-based compounds (BQACs), which remains largely uncharted. This study examines the structure-activity relationship of amphiphilic bicationic compounds as anticancer agents, focusing on their selectivity against pancreatic cancer cells. Our analysis revealed a potent antiproliferative effect associated with mitochondrial accumulation and subsequent mitochondrial membrane depolarization. Furthermore, combination therapies involving BQACs and chemotherapeutic drugs were explored to enhance treatment efficacy. Consequently, we propose a novel combination of BQACs with metformin, resulting in enhanced cellular uptake of the latter. The synergistic effect of the combination enables a significantly lower effective dose of metformin when used alongside BQACs to achieve therapeutic outcomes. Show less
Liquid-liquid phase separation (LLPS)-driven coacervate droplets, formed by the self-assembly of phase-separating molecules, have emerged as a new platform for the intracellular delivery of macromolec Show more
Liquid-liquid phase separation (LLPS)-driven coacervate droplets, formed by the self-assembly of phase-separating molecules, have emerged as a new platform for the intracellular delivery of macromolecular therapeutics such as antibodies, plasmids, and mRNA. Their appeal lies in their high loading capacity, low cytotoxicity, and high cellular uptake efficiency. Beyond traditional polymer and protein systems, recent advances have demonstrated that low-molecular-weight compounds, including peptides and small molecules, can also form functional coacervates. In this perspective, we will discuss and elucidate the possible mechanisms underlying coacervate cellular uptake and highlight their applications in macromolecular delivery and disease therapy. We also provide our perspective on future research directions and translational opportunities. By critically evaluating these aspects, we aim to bridge fundamental insights with translational potential while providing a promising strategy in disease treatment. Show less
The Nature Index tracks the affiliations of high-quality scientific articles. Updated monthly, the Nature Index presents research outputs by institution and country. Use the Nature Index to interrogat Show more
The Nature Index tracks the affiliations of high-quality scientific articles. Updated monthly, the Nature Index presents research outputs by institution and country. Use the Nature Index to interrogate publication patterns and to benchmark research performance.
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2025 · RSC Advances · Royal Society of Chemistry · added 2026-04-20
The direct and atom economic synthesis of azulenyl-substituted gold(i) carbene complexes, based on the modular template synthesis using gold(i) isonitrile complexes and amine nucleophiles, is presente Show more
The direct and atom economic synthesis of azulenyl-substituted gold(i) carbene complexes, based on the modular template synthesis using gold(i) isonitrile complexes and amine nucleophiles, is presented. First, two azulenyl-substituted isonitriles as ligands were synthesized from a functionalizable azulene derivative, the latter stemming from a gold-catalyzed dimerization of internal alkynes. These azulene-bound gold(i) isonitrile complexes allow the smooth nucleophilic attack by both aliphatic and aromatic amines. The newly synthesized azulene-substituted gold(i) carbene complexes were evaluated for in vitro anticancer activity against multiple human cancer cell lines. Six lead compounds demonstrated potent and selective cytotoxicity, exceeding that of cisplatin by at least an order of magnitude in resistant and aggressive cancer models. Structure-activity relationship analysis revealed that specific ligand modifications, such as the position of the azulene moiety tethered to the carbene unit or nitrogen-bound ethyl or cyclic groups, are critical for enhancing the anticancer activity. Show less
2025 · Chemical Society Reviews · Royal Society of Chemistry · added 2026-04-20
The need for selective and efficient anticancer therapies drives the development of gold N-heterocyclic carbene (NHC) as efficient metallodrugs. Their stability, tunable electronics, and versatile ste Show more
The need for selective and efficient anticancer therapies drives the development of gold N-heterocyclic carbene (NHC) as efficient metallodrugs. Their stability, tunable electronics, and versatile steric features make NHCs ideal ligands, which, paired with an antiproliferating gold centre, form an exemplary metal complex for anticancer research. This review highlights the progress made in designing gold NHC complexes, emphasizing strategies to enhance cytotoxicity and selectivity towards cancer cells while minimizing toxicity to healthy tissues, emphasizing the crucial role of the NHC ligand. Furthermore, challenges concerning revealing the precise modes of action are discussed. Mechanistic pathways beyond the inhibition of thioredoxin reductase are highlighted. By underlining recent developments, this review aims to pave the way to a rational design of next-generation gold NHC complexes. Show less
Solvent effects play a critical role in ionic chemical reactions and have been a research topic for a long time. The solvent molecules in the first solvation shell of the solute are the most important Show more
Solvent effects play a critical role in ionic chemical reactions and have been a research topic for a long time. The solvent molecules in the first solvation shell of the solute are the most important solvating species. Consequently, manipulation of the structure of this shell can be used to control the reactivity and selectivity of ionic reactions. In this work, we report extensive experimental and insightful computational studies of the effects of adding diverse fluorinated bulky alcohols with different solvation abilities to the fluorination reaction of alkyl bromides with potassium fluoride promoted by 18-crown-6. We found that adding a stoichiometric amount of these alcohols to the acetonitrile solution has an important effect on the kinetics and selectivity. The most effective alcohol was 2-trifluoromethyl-2-propanol (TBOH-F3), and the use of 3 equiv of this alcohol to fluorinate a primary alkyl bromide led to a 78% fluorination yield in just 6 h of reaction time at a mild temperature of 82 °C, with 8% of E2 yield. The more challenging secondary alkyl bromide substrate obtained 44% fluorination yield and 56% E2 yield at 18 h of reaction time. More fluorinated alcohols with six or more fluorine atoms have resulted in relatively acidic alcohols, leading to large amounts of the corresponding ethers of these alcohols as side products. The widely used hexafluoroisopropanol (HFIP) was the least effective one for monofluorination, indicating that both acidity and bulkiness are important features of the alcohols for promoting fluorination using KF salt. Nevertheless, the ether of HFIP can be easily formed with the substrate, generating a highly fluorinated ether product. Theoretical calculations predict ΔG‡ in close agreement with the experiments and explain the higher selectivity induced by the fluorinated bulky alcohols in relation to the use of crown ether alone. Show less
Electron transfer coupled to redox chemistry is at the heart of metabolism. The proteins responsible for moving electrons (protein electron carriers) must have emerged at the origin of life. The small Show more
Electron transfer coupled to redox chemistry is at the heart of metabolism. The proteins responsible for moving electrons (protein electron carriers) must have emerged at the origin of life. The small iron-sulfur-binding bacterial ferredoxins were likely among these first proteins. Embedded within the ferredoxin sequence and structure is a symmetry that points to an ancient gene duplication event. Little is understood about the nature of ferredoxins prior to this duplication event or what environmental factors may have driven the selection for more complex forms. The deep-time molecular history of ferredoxins goes back billions of years and cannot be reconstructed by phylogenetic analyses based on amino acid sequences. Here, we use structure-guided protein design to model a fossil half-ferredoxin stage in the evolution of this fold, the semidoxins, and their symmetric full-length counterparts, the symdoxins. Semidoxin designs homodimerize, exhibiting structural, thermodynamic, and electrochemical behaviors in most cases identical to cognate symdoxins. However, the semi- and symdoxin fossil stages behave differently when incorporated into an in vivo electron transfer complementation assay. Both can support bacterial growth dependent on protein expression. Growth rates of bacteria expressing the semidoxins are much more sensitive to oxygen than those of bacteria expressing symdoxins. Motivated by the in vivo functionality of designed semidoxins, we identified putative naturally occurring semidoxins in extant anaerobic microorganisms. This is consistent with the observed in vivo oxygen sensitivity of the semidoxin designs. One natural semidoxin is shown to be folded and redox active. However, it exists as a mixture of monomers and dimers, suggesting a potential connection between semidoxins and even simpler single iron-sulfur cluster-binding peptides. Show less
AbstractPhotoactivatable metal complexes offer the prospect of novel drugs with low side effects and new mechanisms of action to combat resistance to current therapy. We highlight recent progress in t Show more
AbstractPhotoactivatable metal complexes offer the prospect of novel drugs with low side effects and new mechanisms of action to combat resistance to current therapy. We highlight recent progress in the design of platinum, ruthenium, iridium, gold and other transition metal complexes, especially for applications as anticancer and anti‐infective agents. In particular, understanding excited state chemistry related to identification of the bioactive species (excited state metallomics/pharmacophores) is important. Photoactivatable metallodrugs are classified here as photocatalysts, photorelease agents and ligand‐activated agents. Their activation wavelengths, cellular mechanisms of action, experimental and theoretical metallomics of excited states and photoproducts are discussed to explore new strategies for the design and investigation of photoactivatable metallodrugs. These photoactivatable metallodrugs have potential in clinical applications of Photodynamic Therapy (PDT), Photoactivated Chemotherapy (PACT) and Photothermal Therapy (PTT). Show less
Abstract Transition metal complexes have been widely utilized as cellular imaging tools. To impart organelle specificity, ligand architecture is usually modified to modulate properties like overall ch Show more
Abstract Transition metal complexes have been widely utilized as cellular imaging tools. To impart organelle specificity, ligand architecture is usually modified to modulate properties like overall charge and lipophilicity. In many such designs, the metal identity and its intrinsic properties are often ignored. To address this gap, in this study, we explored the effects of changing the metal center on the localization patterns of isostructural complexes. To this end, we employed the thiosemicarbazone Dp44mT to synthesize coumarin‐conjugated complexes of Au(III), Pt(II), and Pd(II). Although the metal centers in these compounds share a formal d 8 configuration, they differ in properties such as ionic radius, charge density, and ligand exchange rates, which can affect their subcellular localization patterns. In addition, we synthesized a second set of analogous complexes using BODIPY as the conjugating fluorophore to assess the influence of using a different dye on the cellular distribution. Confocal imaging revealed that the complexes exhibited distinct intracellular distributions. For instance, while the coumarin‐conjugated Pt(II) complex localized specifically in lysosomes, the corresponding lipophilic Pd(II) complex lacked this specificity and instead followed a diffusely cytosolic distribution. Similarly, the more lipophilic BODIPY conjugated complexes were non‐specific in their cellular distribution as well. Overall, the findings of this study highlight the interplay of metal identity and lipophilicity in determining the localization patterns of Dp44mT‐based metal complexes, offering fresh insights into the design of new metal‐based imaging tools. Show less
This study presents the chemical synthesis and biological evaluation of a series of gold(I)-N-heterocyclic carbene complexes as potential anticancer agents. The compounds demonstrated broad activity a Show more
This study presents the chemical synthesis and biological evaluation of a series of gold(I)-N-heterocyclic carbene complexes as potential anticancer agents. The compounds demonstrated broad activity against various cancer cell lines, exhibiting cytotoxicity in the low micromolar range. Mechanistic investigations revealed that these complexes preferentially accumulate in the mitochondria of cancer cells, where they induce the generation of reactive oxygen species and lipid peroxides, ultimately triggering ferroptosis. Further studies in multicellular tumor spheroids confirmed the compounds' ability to penetrate three-dimensional cellular structures and effectively eradicate them at low micromolar concentrations. This work represents the first known example of a gold(I)-N-heterocyclic carbene complex inducing ferroptosis, expanding the therapeutic potential of gold(I)-based metallodrugs. Show less
Cancer cells often upregulate ribosome biogenesis to meet increased protein synthesis demands for rapid proliferation; therefore, targeting ribosome biogenesis has emerged as a promising cancer therap Show more
Cancer cells often upregulate ribosome biogenesis to meet increased protein synthesis demands for rapid proliferation; therefore, targeting ribosome biogenesis has emerged as a promising cancer therapeutic strategy. Herein, we introduce two Pt complexes, ataluren monosubstituted platinum(IV) (SPA, formula: c,c,t,-[Pt(NH3)2Cl2(OH)(C15H8FN2O3)], where C15H8FN2O3 = ataluren) and ataluren bisubstituted platinum(IV) complex (DPA, formula: c,c,t,-[Pt(NH3)2Cl2(C15H8FN2O3)2], where C15H8FN2O3 = ataluren), which effectively suppress ribosome biogenesis by inhibiting 47s pre-RNA expression. Furthermore, SPA and DPA induce nucleolar stress by dispersing nucleolar protein NPM1, ultimately inhibiting protein generation in tumor cells. More importantly, DPA exhibits superior cytotoxicity to various cancer cells and in vivo antitumor efficacy compared to cisplatin, with lower systemic toxicity. Notably, in clinically relevant models, including orthotopic hepatic tumor-bearing mice and patient-derived bladder cancer organoids, DPA outperforms cisplatin significantly, with the added benefit of oral administration, enhancing clinical feasibility. To our knowledge, DPA emerges as the pioneering Pt(IV) agent targeting the ribosome, providing new insights for designing next-generation metal-based therapeutics. Show less
2024 · Chemical Science · Royal Society of Chemistry · added 2026-04-20
The stepwise, one-pot synthesis of heterobimetallic carbene gold(i) platinum(ii) complexes from readily available starting materials is presented. The protecting group free methodology is based on the Show more
The stepwise, one-pot synthesis of heterobimetallic carbene gold(i) platinum(ii) complexes from readily available starting materials is presented. The protecting group free methodology is based on the graduated nucleophilicities of aliphatic and aromatic amines as linkers between both metal centers. This enables the selective, sequential installation of the metal fragments. In addition, the obtained complexes were tested as potential anticancer agents and directly compared to their gold(i) palladium(ii) counterparts. Show less
Targeting inflammation and the molecules involved in the inflammatory process could be an effective cancer prevention and therapy strategy. Therefore, the use of anti-inflammatory strategies, such as Show more
Targeting inflammation and the molecules involved in the inflammatory process could be an effective cancer prevention and therapy strategy. Therefore, the use of anti-inflammatory strategies, such as NSAIDs and metal-based drugs, has become a promising approach for preventing and treating cancer by targeting multiple pathways involved in tumor progression. The present work describes new phosphane gold(I) complexes derived from nonsteroidal anti-inflammatory drugs as multitarget drugs against colon cancer. The antiproliferative effect of the most active complexes, [Au(L3)(JohnPhos)] (3b), [Au(L4)(CyJohnPhos)] (4a) and [Au(L4)(JohnPhos)] (4b) against colon cancer cells (Caco2-/TC7) seems to be mediated by the inhibition of the enzyme cyclooxygenase-1/2, modulation of reactive oxygen species levels by targeting thioredoxin reductase (TrxR) activity, and induction of apoptosis in cancer cells. Additionally, the three complexes exhibit high selectivity index values toward noncancerous cells. The research highlights the importance of maintaining cellular redox balance and the role of TrxR in cancer cell survival. Show less
DNA crosslinking agents such as cisplatin and related platinum(II) analogs are effective drugs to treat solid tumors. However, these therapeutics can cause high toxicity in the body, and tumors can de Show more
DNA crosslinking agents such as cisplatin and related platinum(II) analogs are effective drugs to treat solid tumors. However, these therapeutics can cause high toxicity in the body, and tumors can develop resistance to them. To develop less toxic and more effective DNA crosslinkers, medicinal chemists have focused on tuning the ligands in square planar platinum(II) complexes to modulate their bioavailability, targeted cell penetration, and DNA binding rates. Unfortunately, linking in vitro DNA binding capacity of DNA crosslinkers with their in vivo efficacy has proven challenging. Here we report an electrochemical biosensor strategy that allows the study of platinum(II)-DNA binding in real time. Our biosensors contain a purine-rich deoxynucleotide sequence, T6 (AG)10 , modified with a 5' hexylthiol linker for easy self-assembly onto gold electrodes. The 3' terminus is functionalized with the redox reporter methylene blue. Electron transfer from methylene blue to the sensor is a function of platinum(II) compound concentration and reaction time. Using these biosensors, we resolve DNA binding mechanisms including monovalent and bivalent binding, as well as base stacking. Our approach can measure DNA binding kinetics in buffers and in 50 % serum, offering a single-step, real-time approach to screen therapeutic compounds during drug development. Show less
AbstractStructure elucidation plays a critical role across the landscape of medicinal chemistry, including medicinal inorganic chemistry. Herein, we discuss the importance of structure elucidation in Show more
AbstractStructure elucidation plays a critical role across the landscape of medicinal chemistry, including medicinal inorganic chemistry. Herein, we discuss the importance of structure elucidation in drug development and then provide three vignettes that capture key instances of its relevance in the development of biologically active inorganic compounds. In the first, we describe the exploration of the biological activity of the trinuclear Ru compound called ruthenium red and the realization that this activity derived from a dinuclear impurity. We next explore the development of Au‐based antitubercular and antiarthritic drugs, which features a key step whereby ligands were discovered to bind to Au through S atoms. The third exposition traces the development of As‐based antiparasitic drugs, a key step of which was the realization that the reaction of arsenic acid and aniline does not produce an anilide of arsenic acid, as originally thought, but rather an amino arsonic acid. These case studies provide the motivation for an outlook in which the development of Sb‐based antiparasitic drugs is described. Although antileishmanial pentavalent antimonial drugs remain in widespread use to this day, their chemical structures remain unknown. Show less
Herein, we present a comparative study on the chemistry and biological activity of N-heterocyclic carbene (NHC)Pt(II)/Au(I) complexes. Accordingly, representative compounds of the cis/trans- [PtL2X2] Show more
Herein, we present a comparative study on the chemistry and biological activity of N-heterocyclic carbene (NHC)Pt(II)/Au(I) complexes. Accordingly, representative compounds of the cis/trans- [PtL2X2] (X = Cl (5, 6) or I (7, 8)), [PtL3Cl]+ (9), [AuLX] (X = Cl (10) or I (11)), and [AuL2]+ (12) type, where L is 1,3-diethylbenzimidazol-2-ylidene, were synthesized and characterized in detail to elucidate the role of the metal center on their physicochemical and biological properties. The stability of the complexes in the presence of cell culture medium and their reactivity toward relevant biomolecules were investigated by RP-HPLC. In addition, their effects on plasmid DNA and in vitro cytotoxicity in ovarian cancer cells and non-malignant fibroblasts were evaluated. Cationic [AuL2]+ and [PtL3X]+ species displayed the highest cytotoxicity and stability in cell culture medium in the series. They exhibited IC50 values lower than the established metallodrugs cisplatin and auranofin in both wild-type and cisplatin-resistant ovarian cancer cells, being able to circumvent cisplatin resistance. Finally, Pt(II)–NHC complexes form 5′-guanosine monophosphate adducts under physiologically relevant conditions and interact with plasmid DNA in contrast to their Au(I) analogs, corroborating their distinct modes of action. Show less
The preparation of cyclometalated complexes offers a path to stable materials, catalysts, and therapeutic agents. Here, we explore the anticancer potential of novel biphenyl organogold(III) cationic c Show more
The preparation of cyclometalated complexes offers a path to stable materials, catalysts, and therapeutic agents. Here, we explore the anticancer potential of novel biphenyl organogold(III) cationic complexes supported by diverse bisphosphine ligands, Au-1-Au-5, toward aggressive glioblastoma and triple negative breast cancer cells (TNBCs). The [C^C] gold(III) complex, Au-3, exhibits significant tumor growth inhibition in a metastatic TNBC mouse model. Remarkably, Au-3 displays promising blood serum stability over a relevant therapeutic window of 24 h and alteration in the presence of excess L-GSH. The mechanism-of-action studies show that Au-3 induces mitochondrial uncoupling, membrane depolarization, and G1 cell cycle arrest and prompts apoptosis. To the best of our knowledge, Au-3 is the first biphenyl gold-phosphine complex to uncouple mitochondria and inhibit TNBC growth in vivo. Show less
Mitochondria are double-membrane organelles crucial for oxidative phosphorylation, enabling efficient ATP synthesis by eukaryotic cells. Both of the membranes, the highly selective inner mitochondrial Show more
Mitochondria are double-membrane organelles crucial for oxidative phosphorylation, enabling efficient ATP synthesis by eukaryotic cells. Both of the membranes, the highly selective inner mitochondrial membrane (IMM) and a relatively porous outer membrane (OMM), harbor a number of integral membrane proteins that help in the transport of biological molecules. These transporters are especially enriched in the IMM, where they help maintain transmembrane gradients for H+, K+, Ca2+, PO43-, and metabolites like ADP/ATP, citrate, etc. Impaired activity of these transporters can affect the efficiency of energy-transducing processes and can alter cellular redox state, leading to activation of cell-death pathways or metabolic syndromes in vivo. Although several methodologies are available to study ion flux through membrane proteins, the patch-clamp technique remains the gold standard for quantitatively analyzing electrogenic ion exchange across membranes. Direct patch-clamp recordings of mitoplasts (mitochondria devoid of outer membrane) in different modes, such as whole-mitoplast or excised-patch mode, allow researchers the opportunity to study the biophysics of mitochondrial transporters in the native membrane, in real time, in isolation from other fluxes or confounding factors due to changes in ion gradients, pH, or mitochondrial potential (ΔΨ). Here, we summarize the use of patch clamp to investigate several membrane proteins of mitochondria. We demonstrate how this technique can be reliably applied to record whole-mitoplast Ca2+ currents mediated via mitochondrial calcium uniporter or H+ currents mediated by uncoupling protein 1 and discuss critical considerations while recording currents from these small vesicles of the IMM (mitoplast diameter = 2-5 µm). Show less
Metal complexes have demonstrated significant antitumor activities and platinum complexes are well established in the clinical application of cancer chemotherapy. However, the platinum-based t Show more
Metal complexes have demonstrated significant antitumor activities and platinum complexes are well established in the clinical application of cancer chemotherapy. However, the platinum-based treatment of different types of cancers is massively hampered by severe side effects and resistance development. Consequently, the development of novel metal-based drugs with different mechanism of action and pharmaceutical profile attracts modern medicinal chemists to design and synthesize novel metal-based agents. Among non-platinum anticancer drugs, gold complexes have gained considerable attention due to their significant antiproliferative potency and efficacy. In most situations, the gold complexes exhibit anticancer activities by targeting thioredoxin reductase (TrxR) or other thiol-rich proteins and enzymes and trigger cell death via reactive oxygen species (ROS). Interestingly, gold complexes were recently reported to elicit biochemical hallmarks of immunogenic cell death (ICD) as an ICD inducer. In this review, the recent progress of gold(I) and gold(III) complexes is comprehensively summarized, and their activities and mechanism of action are documented.
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