Synthesis, structures and anticancer potentials of platinum(II) saccharinate complexes of tertiary phosphines with phenyl and cyclohexyl groups targeting mitochondria and DNA

A comprehensive review on anti-inflammatory, antibacterial, anticancer and antifungal properties of several bivalent transition metal complexes

Transition metal complexes have been recognized as possible therapeutic agents, attributed to their special biological actions, including anti-inflammatory, antibacterial, antifungal, and anticancer. The pharmacological perspective connected with Copper (Cu), Cobalt (Co), Nickel (Ni), Manganese (Mn), Palladium (Pd), Zinc (Zn), and Platinum (Pt) metal(II) complexes is comprehensively explored in-depth in this research. The complexes show unique coordination chemistry and modes of action that help interactions with biological targets, including DNA binding, enzyme inhibition, and the formation of reactive oxygen species. All the metal(II) complexes showed notable potential impact in their perspective activity. Conspicuously, Co(II) and Ni(II) complexes show better antibacterial and antifungal action, while Cu(II) and Zn(II) combinations show higher anti-inflammatory activity. While research is constantly investigating alternative metal-based anticancer drugs like Pd(II), which seem to have lowered side effects, Pt(II) complexes especially cisplatin continue to be the benchmark in cancer treatment. Although the possible pharmacological actions are motivating, problems with toxicity and biocompatibility still provide major difficulties, especially in relation to Cd(II) and Hg(II) complexes. Strategies like ligand modification, nanoparticle-based delivery, and prodrug methods are used to increase selectivity and reduce side effects related to metal complexes. This review compiles the most recent developments and continuous research, thereby shedding light on the potential revolutionary power of metal(II) complexes in medical therapy. Understanding their mechanisms and enhancing their safety profiles will help us open the path to creative ideas for addressing some of the most urgent medical issues of today.

RuIII-Morpholine-Derived Thiosemicarbazone-Based Metallodrugs: Lysosome-Targeted Anticancer Agents

The idea of coordinating biologically active ligand systems to metal centers to exploit their synergistic effects has gained momentum. Therefore, in this report, three RuIII complexes 1-3 of morpholine-derived thiosemicarbazone ligands have been prepared and characterized by spectroscopy and HRMS along with the structure of 2 through a single-crystal X-ray diffraction study. The solution stability of 1-3 was tested using conventional techniques such as UV-vis and HRMS. Further, the anticancer activity of 1-3 was tested in HT-29 and HeLa cancer cell lines. To gain insight into their mechanism of action, the cytotoxicity, hydrophobicity, and the interaction of 1-3 with DNA and HSA were evaluated by different conventional methods such as absorption, fluorescence, and circular dichroism studies. Along with favorable biomolecule interaction, 1-3 revealed potent selectivity toward cancer cells, which is a prerequisite for the generation of an anticancer drug. According to cell viability results, 1 has the highest cytotoxicity among all in the group, against both cells, respectively. Additionally, the fluorescence-active ruthenium complexes selectively target lysosomes, which is evaluated by live-cell imaging. 1-3 disrupt the lysosome membrane potential by generating an excessive amount of reactive oxygen species, which results in an apoptotic mode of cell death.

Exploring the Potential Fungicidal Applications of a Cu(II) Complex with Schiff Base and Carboxylates against Fusarium equisetum

Given the critical need to preserve agricultural sustainability, there is an urgent call to address fungal infections. Our study presents a promising approach by focusing on SIX (Secreted in Xylem) proteins as a pivotal target for the development of innovative fungicidal strategies. Within the sphere of this study, we meticulously scrutinize the antifungal efficacy of our synthesized Cu(II) complex formulated as [Cu(L1)2(L2)]+(ClO4)-, where L1 represents (E)-cyclohexyl-N(pyridine-2-xlmethylene) methanamine and L2H denotes cinnamic acid, compared against a commercially available fungicide comprising 4% hexaconazole and 68% zineb. Employing in silico methodologies, we undertake a comparative analysis targeting SIX proteins to discern the potency of our compound. The X-ray diffraction, 1H NMR, and FTIR spectroscopic techniques were utilized to elucidate the structure of the complex methodically. The lipophilicity test of the complex signifies its potential lipophilic nature and prompted further investigation into the complex's interaction with DNA (DNA) and bovine serum albumin (BSA). The binding constant values suggested a notable interaction between the complex and both DNA and BSA. The antifungal test reveal that our complex emerges as a potent contender in the battle against Fusarium equisetum (F.E.), exhibiting a commendable efficacy that positions it as a viable substitute for the incumbent commercial fungicide. This discovery predicts well the prospect of bolstering agricultural resilience and safeguarding global food security in the face of pervasive fungal threats.

Advancements in platinum-based anticancer drug development: A comprehensive review of strategies, discoveries, and future perspectives

Platinum-based anticancer drugs have been at the forefront of cancer chemotherapy, with cisplatin emerging as a pioneer in the treatment of various malignancies. This review article provides a comprehensive overview of the evolution of platinum-based anticancer therapeutics, focusing on the development of cisplatin, platinum(IV) prodrugs, and the integration of photodynamic therapy (PDT) for enhanced cancer treatment results. The first section of the review delves into the historical context and molecular mechanisms underlying the success of cisplatin, highlighting its DNA binding properties and subsequent interference with cellular processes. Despite its clinical efficacy, the inherent limitations, including dose-dependent toxicities and acquired resistance, accelerated the exploration of novel platinum derivatives. This led to the emergence of platinum(IV) prodrugs, designed to overcome resistance mechanisms and enhance selectivity through targeted drug delivery. The subsequent section provides an in-depth analysis of the principles of design and structural modifications employed in the development of platinum(IV) prodrugs. The transitions to the incorporation of photodynamic therapy (PDT) stands out as a synergistic approach to platinum-based anticancer treatment. The photophysical properties of platinum complexes are discussed in the context of their potential application in PDT, emphasizing on combined cytotoxic effects of platinum-based drugs and light-induced reactive oxygen species generation. This dual-action approach holds great promise for overcoming the limitations of traditional chemotherapy as well as producing superior therapeutic outcomes. Overall, the present report explores the latest developments in the development and use of platinum complexes, highlighting novel strategies such combination treatments, targeted delivery methods, and the generation of multifunctional complexes. It also provides a comprehensive overview of the current landscape while proposing future directions for the development of next-generation platinum-based anticancer therapeutics.

Trans-[Pt(amine)Cl2(PPh3)] Complexes Target Mitochondria and Endoplasmic Reticulum in Gastric Cancer Cells

Gastric cancer prognosis is still notably poor despite efforts made to improve diagnosis and treatment of the disease. Chemotherapy based on platinum agents is generally used, regardless of the fact that drug toxicity leads to limited clinical efficacy. In order to overcome these problems, our group has been working on the synthesis and study of trans platinum (II) complexes. Here, we explore the potential use of two phosphine-based agents with the general formula trans-[Pt(amine)Cl2(PPh3)], called P1 and P2 (with dimethylamine or isopropylamine, respectively). A cytotoxicity analysis showed that P1 and especially P2 decrease cell viability. Specifically, P2 exhibits higher activity than cisplatin in gastric cancer cells while its toxicity in healthy cells is slightly lower. Both complexes generate Reactive Oxygen Species, produce DNA damage and mitochondrial membrane depolarization, and finally lead to induced apoptosis. Thus, an intrinsic apoptotic pathway emerges as the main type of cell death through the activation of BAX/BAK and BIM and the degradation of MCL1. Additionally, we demonstrate here that P2 produces endoplasmic reticulum stress and activates the Unfolded Protein Response, which also relates to the impairment observed in autophagy markers such as p62 and LC3. Although further studies in other biological models are needed, these results report the biomolecular mechanism of action of these Pt(II)-phosphine prototypes, thus highlighting their potential as novel and effective therapies.

1,3,5-Triaza-7-phosphaadamantane and Cyclohexyl Groups Impart to Di-Iron(I) Complex Aqueous Solubility and Stability, and Prominent Anticancer Activity in Cellular and Animal Models

Using a multigram-scalable synthesis, we obtained nine dinuclear complexes based on nonendogenous iron(I) centers and featuring variable aminocarbyne and P-ligands. One compound from the series (FEACYP) emerged for its strong cytotoxicity in vitro against four human cancer cell lines, surpassing the activity of cisplatin by 3-6 times in three cell lines, with an average selectivity index of 6.2 compared to noncancerous HEK293 cells. FEACYP demonstrated outstanding water solubility (15 g/L) and stability in physiological-like solutions. It confirmed its superior antiproliferative activity when tested in 3D spheroids of human pancreatic cancer cells and showed a capacity to inhibit thioredoxin reductase (TrxR) similar to auranofin. In vivo treatment of murine LLC carcinoma with FEACYP (8 mg kg-1 dose) led to excellent tumor growth suppression (88%) on day 15, with no signs of systemic toxicity and only limited body weight loss.

Comparative Linkage of Novel Anti-Tumor Pd(II) Complex with Bio-Macromulecules: Fluorescence, UV-Vis, DFT, Molecular Docking and Molecular Dynamics Simulation Studies

A novel mononuclear palladium complex, [Pd(dach)(SSA)], where dach and SSA are diaminocyclohexane and sulfosalicylic acid ligands, respectively, has been synthesized and identified utilizing analytical and spectral methods. DFT calculations, namely geometry optimization, MEP, HOMO-LUMO and NBO analysis, have been conducted at B3LYP level by aug-ccpVTZ-PP and 6-311G(d, p) basis sets. NBO and HOMO-LUMO analysis exhibited that the palladium compound is stable. MEP showed the potential sites of molecule for the interaction. By employing MTT assay, the cytotoxicity activity of the aforesaid compound was examined on K562 cell line, which revealed a proper activity compared to cisplatin. To ascertain the lipophilicity of the newly made compound, the partition coefficient measurement was accomplished, which follows the order of cisplatin < Pd(II) complex. Next, investigation of binding properties of the studied compound with DNA of calf thymus and BSA were done by spectroscopic (CD, fluorescence emission and electronic adsorption) and non-spectroscopic (viscosity measurements, DNA gel electrophoresis, molecular docking and molecular dynamics simulation) methods. The outcomes of CD and UV-Vis spectroscopy demonstrated that the title compound refolded the protein via increasing the alpha helix percentage. The data obtained from UV-Vis studies indicated the non-intercalative mutual action between Pd(II) complex with DNA. It also revealed that the Kapp magnitude of CT-DNA (7.43 × 104 M- 1) is higher than the BSA (5.17 × 103 M- 1), and L1/2 (midpoint of transition) of CT-DNA (5 µM) is lower than the BSA (5.7 µM), indicating that the complex has a greater binding affinity to CT-DNA than BSA. Fluorescence quenching mechanism of the two biomolecules by the metal complex is static and the calculated thermodynamic parameters (ΔS° < 0 and ΔH° < 0) suggested the hydrogen bonding and/ or van der Waals forces with DNA and BSA. Further, molecular docking indicated that the studied compound fits into the groove of DNA and the site I of BSA. The stability of metal compound-DNA/-BSA in the presence of H2O solvent and over the time were validated via molecular dynamics simulation.

Computational and experimental examinations of new antitumor palladium(II) complex: CT-DNA-/BSA-binding, in-silico prediction, DFT perspective, docking, molecular dynamics simulation and ONIOM

Since the design of metal complexes with better biological activities is important, herein a new palladium(II) complex bearing en and acac (en and acac stand for ethylenediamine and acetylacetonato, respectively) as its ligands, [Pd(en)(acac)]NO3 complex, was synthesized and fully characterized. Quantum chemical computations of the palladium(II) complex were done via DFT/B3LYP method. Cytotoxicity activity of the new compound on leukemia cell line (K562) was assessed via MTT method. The findings indicated that the metal complex has remarkable cytotoxic effect than cisplatin. OSIRIS DataWarrior software was employed to calculate in-silico physicochemical and toxicity parameters of the synthesized complex which rendered significant results. To comprehend the interaction type of new metal compound with macromolecules, the in depth investigation of interaction of mentioned complex with CT-DNA and BSA was accomplished by fluorescence, UV-Visible absorption spectroscopy, viscosity measurement, gel electrophoresis, FRET analysis and circular dichroism (CD) spectroscopy. On the other hand, computational molecular docking was carried out and the obtained data demonstrated that H-bond and van der Waals forces are the dominant forces for the binding of the compound to the mentioned biomolecules. Molecular dynamics simulation was also done and confirmed the stability of best docked pose of palladium(II) complex inside DNA or BSA over the time and in presence of water solvent. Also, Our own N-layered Integrated molecular Orbital and molecular Mechanics (ONIOM) methodology based on the hybridization of quantum mechanics and molecular mechanics (QM/MM) methodology was accomplished to inquire about binding of Pd(II) complex with DNA or BSA.HIGHLIGHTSNew biologically active Pd(II) complex was synthesized and characterized.The in silico studies of the designed complex and its ligands were accomplished by OSIRIS DataWarrior softwareInteraction with CT-DNA and BSA was assessed by various spectroscopic methods.Molecular docking simulation supported the interaction with both macromolecules.Based on ONIOM analysis, the structures of the complex and biomolecules are altered after binding. Communicated by Ramaswamy H. Sarma.

Effect of Cu(II) compound containing dipicolinic acid on DNA damage: a study of antiproliferative activity and DNA interaction properties by spectroscopic, molecular docking and molecular dynamics approaches

A polymeric compound formulized as [Cu(µ-dipic)2{Na2(µ-H2O)4]n.2nH2O (I), where dipic is 2,6-pyridine dicarboxylic acid (dipicolinic acid, H2dipic), was synthesized by sonochemical irradiation. The initial in-vitro cytotoxic activity of this complex compared with renowned anticancer drugs like cisplatin, versus HCT116 colon cell lines, shows promising results. This study investigated the interaction mode between compound (I) and calf-thymus DNA utilizing a range of analytical techniques including spectrophotometry, fluorimetry, partition coefficient analysis, viscometry, gel electrophoresis and molecular docking technique. The results obtained from experimental methods reveal complex (I) could bind to CT-DNA via hydrogen bonding and van der Waals forces and the theoretical methods support it. Also, complex (I) indicates nuclease activity in the attendance of H2O2 and can act as an artificial nuclease to cleave DNA with high efficiency.

Recently Reported Biological Activities and Action Targets of Pt(II)- and Cu(II)-Based Complexes

Most diseases that affect human beings across the world are now treated with drugs of organic origin. However, some of these are associated with side effects, toxicity, and resistance phenomena. For the treatment of many illnesses, the development of new molecules with pharmacological potential is now an urgent matter. The biological activities of metal complexes have been reported to have antitumor, antimicrobial, anti-inflammatory, anti-infective and antiparasitic effects, amongst others. Metal complexes are effective because they possess unique properties. For example, the complex entity possesses the effective biological activity, then the formation of coordination bonds between the metal ions and ligands is controlled, metal ions provide it with extraordinary mechanisms of action because of characteristics such as d-orbitals, oxidation states, and specific orientations; metal complexes also exhibit good stability and good physicochemical properties such as water solubility. Platinum is a transition metal widely used in the design of drugs with antineoplastic activities; however, platinum is associated with side effects which have made it necessary to search for, and design, novel complexes based on other metals. Copper is a biometal which is found in living systems; it is now used in the design of metal complexes with biological activities that have demonstrated antitumoral, antimicrobial and anti-inflammatory effects, amongst others. In this review, we consider the open horizons of Cu(II)- and Pt(II)-based complexes, new trends in their design, their synthesis, their biological activities and their targets of action.

Mitochondria-targeted cyclometalated iridium (III) complexes: Dual induction of A549 cells apoptosis and autophagy

In this study, we synthesized 4 cyclometalated iridium complexes using N-(1,10-phenanthrolin-5-yl)picolinamide (PPA) as the main ligand, denoted as [Ir(ppy)2PPA]PF6 (ppy = 2-phenylpyridine, Ir1), [Ir(bzq)2PPA]PF6 (bzq = benzo[h]quinoline, Ir2), [Ir(dfppy)2PPA]PF6 (dfppy = 2-(3,5-difluorophenyl)pyridine, Ir3), and [Ir(thpy)2PPA]PF6 (thpy = 2-(thiophene-2-yl)pyridine, Ir4). Compared to cisplatin and oxaliplatin, all four complexes exhibited significant anti-tumor activity. Among them, Ir2 demonstrated higher cytotoxicity against A549 cells, with an IC50 value of 1.6 ± 0.2 μM. The experimental results indicated that Ir2 primarily localized in the mitochondria, inducing a large amount of reactive oxygen species (ROS) generation, that decreased in mitochondrial membrane potential (MMP), reduced ATP production, and further impaired mitochondrial function, leading to cytochrome c release. Additionally, Ir2 caused cell cycle arrest at the S phase and induced apoptosis through the AKT-mediated signaling pathway. Further investigations revealed that Ir2 could simultaneously induce both apoptosis and autophagy in A549 cells, with the latter acting as a non-protective mechanism that promoted cell death. More importantly, Ir2 exhibited low toxicity to both normal LO2 cells in vitro and zebrafish embryos in vivo. Consequently, these newly developed Ir(III) complexes show great potential in the development of novel and low-toxicity anticancer agents.

In Vitro Insight on Antifungal-Specific Potentiality of Ni(II) Complex against Colletotrichum siamense and Fusarium equisetum Phytopathogens

In an initiation to investigate a prospective bioactive compound, a mononuclear Ni(II) complex with N, N, and O donor Schiff base ligand was synthesized and characterized in the present study through FTIR, ESI-mass, and X-ray crystallographic diffraction studies. A slightly distorted octahedral geometry has been obtained for the Ni(II) complex from X-ray crystallographic diffraction studies. In vitro comprehensive biological studies show the antifungal specific efficiency of the complex against Colletotrichum siamense (AP1) and Fusarium equisetum (F.E.) pathogens, which are responsible for anthracnose and wilt disease, respectively, but no inhibitory effect on both Gram-positive and Gram-negative bacteria. The minimum inhibitory concentration (MIC) for these pathogens was observed to be 0.25 and 0.5 mM, respectively. The experiment also reveals that significant damage of mycelia and enlarged, misshaped damaged spores are noticed in comparison to hexaconazole, used as a positive control under a light microscope post 48 h treatment of AP1 and F.E. with the MIC of the complex. The binding interaction studies of the complex with DNA and BSA performed through a variety of spectroscopic techniques demonstrate a strong binding behavior of the complex for both the binding systems. The observed negative ΔH° and ΔS° values for DNA reveal the existence of hydrogen-bonding/van der Waals interactions for DNA which was also exemplified from the molecular docking and self-assembly studies of the complex. The positive ΔH° and ΔS° values for BSA demonstrate the hydrophobic interactions of the complex with BSA. However, cytotoxicity studies against the MDA-MB-231 breast cancer cell line did not demonstrate any significant potentiality of the complex as an anticancer agent. All the bio-experimental studies provide clear evidence that the synthesized Ni(II) complex exhibits potential antifungal activity and could be used as a therapeutic fungicide agent in comparison to hexaconazole in agricultural practices.

Exploring the antioxidant, antimicrobial, cytotoxic and biothermodynamic properties of novel morpholine derivative bioactive Mn(ii), Co(ii) and Ni(ii) complexes - combined experimental and theoretical measurements towards DNA/BSA/SARS-CoV-2 3CLPro

A novel class of bioactive complexes (1-3) [MII(L)2(bpy)], where, L = 2-(4-morpholinobenzylideneamino)phenol, bpy = 2,2'-bipyridine, MII = Mn (1), Co (2) or Ni (3), were assigned to octahedral geometry based on analytical and spectral measurements. Gel electrophoresis showed that complex (2) demonstrated significant DNA cleavage activity compared to the other complexes under the action of oxidation agent (H2O2). The DNA binding constant properties measured by various techniques were in the following sequence: (2) > (3) > (1) > (HL), which suggests that the complexes might intercalate DNA, a possibility that is also supported by their biothermodynamic characteristics. The binding constant results for BSA from electronic absorption and fluorometric titrations demonstrate that complex (2) exhibits the highest binding effectiveness among them all, which means that all the compounds could interact with BSA through a static approach, additionally supported by FRET measurements. DFT and docking calculations were employed to realize the electronic structure, reactivity, and interaction capability of all substances with DNA, BSA, and the SARS-CoV-2 main protease. These binding energies fell within the ranges -7.7 to -8.5, -8.2 to -10.1 and -6.7 to -9.3 kcal mol-1, respectively. The higher reactivity of the complexes than the ligand is supported by FMO theory. The in vitro antibacterial, cytotoxicity, and radical scavenging characteristics revealed that complexes (2-3) have better biological efficacy than the others. The cytotoxicity and binding properties also show good correlation with the partition coefficient (log P), which is encouraging because all of the experimental findings are closely correlated with the theoretical measurements.

Preparation of a Pt(II)-3-Hydroxy-2-tolyl-4H-chromen-4-one Complex Having Antimicrobial, Anticancerous, and Radical Scavenging Activities with Related Computational Studies

A novel benzopyran-based platinum (II)-3-hydroxy-2-tolyl-4H-chromen-4-one (HToC) complex has been prepared and studied by UV-visible spectrophotometry. The study is based on the colored complexation between Pt(II) and HToC in the pH range of 8.92-9.21, resulting in the formation of a stable binary yellow complex exhibiting λmax at 509-525 nm. The formed complex maintains linearity between 0.0 and 1.8 μg Pt(II) mL-1. The well-known qualitative analytical methods, including Job's method of continuous variations and the mole ratio approach, have both proven that the stoichiometry of the complex is 1:2 [Pt(II)/HToC]. Hence, the analytical results suggest that the formed platinum complex exhibits a square planar geometry. The values of various attributes corresponding to spectrophotometric studies and statistical calculations, such as the molar extinction coefficient (6.790 × 104 L mol-1 cm-1), Sandell's sensitivity (0.0029 μg Pt(II) cm-2), standard deviation (± 0.0011), RSD (0.317%), limit of detection (0.0147 μg mL-1) and correlation coefficient (0.9999), show that the performed study satisfies all of the criteria for good sensitivity, versatility, and cost-effectiveness. In order to have an apprehension of the molecular geometry and other structural specifics of the complex, DFT studies have been carried out. The in vitro anticancer potential of the ligand and its platinum complex in the human breast cancer cell line (T-27D), as determined by the MTT assay, reveals that the complex has better antiproliferative potential than the ligand. The antimicrobial potential of the complex has been successfully tested against both Gram-positive and -negative bacteria. Antioxidant capacity results suggest the better radical scavenging capacity of the complex than that of the ligand.

Disparities in Cisplatin-Induced Cytotoxicity-A Meta-Analysis of Selected Cancer Cell Lines

Cisplatin is a classic anticancer drug widely used as a reference drug to test new metal complex drug candidates. We found an unexpected diversity in cisplatin-related cytotoxicity values, expressed as IC50 (the half-maximal inhibitory concentration) in tumour cell lines, such as MCF-7, HepG2 and HeLa. We reviewed the data published from 2018 to 2022. A total of 41 articles based on 56 in vitro experiments met our eligibility criteria. Using a meta-analysis based on a random effect model, we evaluated the cytotoxicity of cisplatin (IC50) after 48- or 72-h cell exposure. We found large differences between studies using a particular cell line. According to the random effect model, the 95% confidence intervals for IC50 were extremely wide. The heterogeneity of cisplatin IC50, as measured by the I2 index for all cancer cell lines, was over 99.7% at culture times of 48 or 72 h. Therefore, the variability between studies is due to experimental heterogeneity rather than chance. Despite the higher IC50 values after 48 h than after 72 h, the heterogeneity between the two culture periods did not differ significantly. This indicates that the duration of cultivation is not the main cause of heterogeneity. Therefore, the available data is diverse and not useful as a reference. We discuss possible reasons for the IC50 heterogeneity and advise researchers to conduct preliminary testing before starting experiments and not to solely rely on the published data. We hope that this systematic meta-analysis will provide valuable information for researchers searching for new cancer drugs using cisplatin as a reference drug.

Potent saccharinate-containing palladium(II) complexes for sensitization to cancer therapy

Palladium(II) (Pd^II) complexes are among the most promising anticancer compounds. Both 2`-benzoylpyridine thiosemicarbazone (BpT) and saccharinate (Sac) are efficient metal chelators with potent anticancer activity. To explore a more effective new anticancer drug, we synthesized a series of Sac and BpT-containing Pd^II complexes coordinated with thiosemicarbazone (TSC)-derived ligands, and characterized them through nuclear magnetic resonance (NMR), Fourier transformed infrared spectroscopy (FT-IR), elemental analysis, ultraviolet-visible spectroscopy (UV-Vis) and thermogravimetric analysis (TGA). Each target complex was composed of Pd^II, BpT, and one or two Sac molecules. Both the in vitro and in vivo anti-growth effects of those ligands and the obtained Pd^II complexes were investigated in the human lung adenocarcinoma cell lines A549 and Spc-A1. The coordination of Pd^II with the TSC-derivatives and Sac resulted in clearly greater anticancer activity than single ligands. These compounds were demonstrated to be safe for 293 T normal human kidney epithelial cells. The introduction of Sac into the TSC-derived Pd^II complex significantly enhanced anti-growth effects, and induced apoptosis of human lung cancer cells in vitro and in vivo in a dose dependent manner. Moreover, the Pd^II complex containing two Sac molecules showed the most promising therapeutic effects, thereby confirming that Sac increases the cancer therapeutic efficacy of Pd^II complexes and providing a new strategy for exploring anticancer drugs for potential clinical treatment.

Biological activity of bis-(morpholineacetato)palladium(II) complex: Preparation, structural elucidation, cytotoxicity, DNA-/serum albumin-interaction, density functional theory, in-silico prediction and molecular modeling

In an effort to discover a novel potential bioactive compound, a mono-nuclear Pd(II) complex with an amino acid derivative as ligand was synthesized and characterized through experimental and computational methodologies. A square-planar configuration was suggested for palladium(II) complex utilizing density functional theory. MEP map and Mulliken atomic charge were detected electrophilic and nucleophilic regions of the compound for reactions. The lipophilicity and cytotoxic activity of the complex was more effective than cisplatin. Also, OSIRIS DataWarrior revealed proper oral bioavailability and good drug-likeness for the compound. In-vitro binding behavior of the Pd(II) complex with DNA and serum albumin (BSA) were fully determined via variety of procedures including fluorescence, UV-Vis, CD, viscosity, gel electrophoresis experiments and molecular simulation. The negative signs of ΔH° and ΔS° for Pd(II) complex-CT-DNA/-BSA systems indicated the existence of hydrogen bonding/van der Waals interactions for both binding systems. Additionally, docking simulation illustrated the interaction of Pd(II) complex with the minor groove of DNA and the hydrophobic cavity of the BSA (drug binding site I).

Targeting the mitochondria in chronic respiratory diseases

Mitochondria are one of the basic essential components for eukaryotic life survival. It is also the source of respiratory ATP. Recently published studies have demonstrated that mitochondria may have more roles to play aside from energy production. There is an increasing body of evidence which suggest that mitochondrial activities involved in normal and pathological states contribute to significant impact to the lung airway morphology and epithelial function in respiratory diseases such as asthma, COPD, and lung cancer. This review summarizes the pathophysiological pathways involved in asthma, COPD, lung cancer and highlights potential treatment strategies that target the malfunctioning mitochondria in such ailments. Mitochondria are responsive to environmental stimuli such as infection, tobacco smoke, and inflammation, which are essential in the pathogenesis of respiratory diseases. They may affect mitochondrial shape, protein production and ultimately cause dysfunction. The impairment of mitochondrial function has downstream impact on the cytosolic components, calcium control, response towards oxidative stress, regulation of genes and proteins and metabolic activities. Several novel compounds and alternative medicines that target mitochondria in asthma and chronic lung diseases have been discussed here. Moreover, mitochondrial enzymes or proteins that may serve as excellent therapeutic targets in COPD are also covered. The role of mitochondria in respiratory diseases is gaining much attention and mitochondria-based treatment strategies and personalized medicine targeting the mitochondria may materialize in the near future. Nevertheless, more in-depth studies are urgently needed to validate the advantages and efficacy of drugs that affect mitochondria in pathological states.

Probing the biomolecular (DNA/BSA) interaction by new Pd(II) complex via in-depth experimental and computational perspectives: synthesis, characterization, cytotoxicity, and DFT approach

Scientists should not forget that the rate of death as a result of cancer is far more than that of other diseases like influenza or coronavirus (COVID-19), so the research in this field is of cardinal significance. Therefore, a new and hydrophilic palladium(II) complex of the general formula [Pd(bpy)(proli-dtc)]NO₃, in which bpy and proli-dtc are 2,2'-bipyridine and pyrroline dithiocarbamate ligands, respectively, was synthesized and characterized utilizing spectral and analytical procedures. Density functional theory (DFT) calculation was also performed with B3LYP method in the gas phase. The DFT and spectral analysis specified that the Pd(II) atom is found in a square-planar geometry. HOMO/LUMO analysis, quantum chemical parameters and MEP surface of the complex were investigated to acquire an intuition about the nature of the compound. Partition coefficient and water solubility determination showed that both lipophilicity and hydrophilicity of the compound are more than cisplatin. The 50% inhibition concentration (IC₅₀) value was evaluated against K562 cancer cells, the obtained result has revealed a promising cytotoxic effect. DNA and BSA binding of the complex were explored through multi-spectroscopic (UV–Vis, fluorescence, FRET, and CD) and non-spectroscopic (gel electrophoresis, viscosity and docking simulation) techniques. The obtained findings demonstrated that the complex strongly interacts with CT-DNA by hydrophobic interactions and possesses medium interaction with BSA via hydrogen bond and van der Waals forces, thus BSA could efficiently carry out complex transportation. Furthermore, the results of docking simulation agree well with the experimental findings. In conclusion, the new Pd(II) complex has cytotoxic activity and could interact with DNA and BSA effectively.

Mo(VI) Potential Metallodrugs: Explaining the Transport and Cytotoxicity by Chemical Transformations

The transport and cytotoxicity of molybdenum-based drugs have been explained with the concept of chemical transformation, a very important idea in inorganic medicinal chemistry that is often overlooked in the interpretation of the biological activity of metal-containing systems. Two monomeric, [MoO₂(L¹)(MeOH)] (1) and [MoO₂(L²)(EtOH)] (2), and two mixed-ligand dimeric Mo^VIO₂ species, [{MoO₂(L^1-2)}₂(μ-4,4'-bipy)] (3-4), were synthesized and characterized. The structures of the solid complexes were solved through SC-XRD, while their transformation in water was clarified by UV-vis, ESI-MS, and DFT. In aqueous solution, 1-4 lead to the penta-coordinated [MoO₂(L^1-2)] active species after the release of the solvent molecule (1 and 2) or removal of the 4,4'-bipy bridge (3 and 4). [MoO₂(L^1-2)] are stable in solution and react with neither serum bioligand nor cellular reductants. The binding affinity of 1-4 toward HSA and DNA were evaluated through analytical and computational methods and in both cases a non-covalent interaction is expected. Furthermore, the in vitro cytotoxicity of the complexes was also determined and flow cytometry analysis showed the apoptotic death of the cancer cells. Interestingly, μ-4,4'-bipy bridged complexes 3 and 4 were found to be more active than monomeric 1 and 2, due to the mixture of species generated, that is [MoO₂(L^1-2)] and the cytotoxic 4,4'-bipy released after their dissociation. Since in the cytosol neither the reduction of Mo^VI to Mo^V/IV takes place nor the production of reactive oxygen species (ROS) through Fenton-like reactions of 1-4 with H₂O₂ occurs, the mechanism of cytotoxicity should be attributable to the direct interaction with DNA that happens with a minor-groove binding which results in cell death through an apoptotic mechanism.

Probing the interaction of new and biologically active Pd(II) complex with DNA/BSA via joint experimental and computational studies along with thermodynamic, NLO, FMO and NBO analysis

Treatment with transition metal complexes is an efficient method to fight with cancer. Therefore, a new transition metal complex formulated as [Pd(1, 3-pn)(acac)]Cl (pn and acac stand for propylendiamine and acetylacetonate, respectively) was synthesized and analyzed using ¹H NMR, Fourier transform infrared, electronic absorption spectroscopy techniques as well as elemental analysis and conductivity measurement. The geometry optimization, frontier molecular orbital (FMO) analysis, molecular electrostatic potential (MEP), natural bond orbital (NBO) analysis and nonlinear optical (NLO) property were accomplished by density functional theory (DFT) at B3LYP level with 6-311G(d,p)/aug-cc-pVTZ-PP basis set. Preliminary determination of antitumor activity and lipophilicity of this metal complex was performed experimentally and the promising results were obtained. This encouraged us to study the interaction and binding mode/modes of this complex with DNA as the primary receptor for the chemotropic drugs and BSA as the transporter protein in the circulatory system. For this reason, the binding of newly made complex was assessed in-vitro under physiological state using experimental and in-silico molecular modeling studies. So, the CT-DNA binding study of this complex was explored using spectrofluorometric as well as spectrophotometric techniques, viscosity and gel electrophoresis experiments. Furthermore, fluorescence, UV-Vis, F[Formula: see text]rster resonance energy transfer and circular dichroism studies were carried out for BSA binding. The experimental and computational interaction studies showed that [Pd(1, 3-pn)(acac)]Cl complex binds to the minor groove of CT-DNA and interacts with BSA by van der Waals forces and hydrogen bond.

Metal Complexes or Chelators with ROS Regulation Capacity: Promising Candidates for Cancer Treatment

Reactive oxygen species (ROS) are rapidly eliminated and reproduced in organisms, and they always play important roles in various biological functions and abnormal pathological processes. Evaluated ROS have frequently been observed in various cancers to activate multiple pro-tumorigenic signaling pathways and induce the survival and proliferation of cancer cells. Hydrogen peroxide (H2O2) and superoxide anion (O2•-) are the most important redox signaling agents in cancer cells, the homeostasis of which is maintained by dozens of growth factors, cytokines, and antioxidant enzymes. Therefore, antioxidant enzymes tend to have higher activity levels to maintain the homeostasis of ROS in cancer cells. Effective intervention in the ROS homeostasis of cancer cells by chelating agents or metal complexes has already developed into an important anti-cancer strategy. We can inhibit the activity of antioxidant enzymes using chelators or metal complexes; on the other hand, we can also use metal complexes to directly regulate the level of ROS in cancer cells via mitochondria. In this review, metal complexes or chelators with ROS regulation capacity and with anti-cancer applications are collectively and comprehensively analyzed, which is beneficial for the development of the next generation of inorganic anti-cancer drugs based on ROS regulation. We expect that this review will provide a new perspective to develop novel inorganic reagents for killing cancer cells and, further, as candidates or clinical drugs.

Anticancer effect evaluation in vitro and in vivo of iridium(III) polypyridyl complexes targeting DNA and mitochondria

To investigate the antitumor effect of iridium complexes, three iridium (III) complexes [Ir(ppy)₂(dcdppz)]PF₆ (ppy = 2-phenylpyridine, dcdppz = 11,12-dichlorodipyrido[3,2-a:2',3'-c]phenazine) (Ir1), [Ir(bzq)₂(dcdppz)]PF₆ (bzq = benzo[h]quinoline) (Ir2) and [Ir(piq)₂(dcdppz)]PF₆ (piq = 1-phenylisoquinoline) (Ir3) were synthesized and characterized. Geometry optimization, molecular dynamics simulation and docking studies have been performed to further explore the antitumor mechanism. The cytotoxicity of Ir1-3 toward cancer cells was studied by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) method. The localization of complexes Ir1-3 in the mitochondria, intracellular accumulation of reactive oxygen species (ROS) levels, the changes of mitochondrial membrane potential and morphological changes in apoptosis were investigated. Flow cytometry was applied to quantify fluorescence intensity and determine cell cycle distribution. Western blotting was used to detect the expression of apoptosis-related proteins. The anti-tumor effect of Ir1 in vivo was evaluated. The results showed that Ir1-3 had high cytotoxicity to most tumor cells, especially to SGC-7901 cells with a low IC₅₀ value. Ir1-3 can increase the intracellular ROS levels, reduce the mitochondrial membrane potential. Additionally, the complexes induce an increase of apoptosis-related protein expression, enhance the percentage of apoptosis. The complexes inhibit the cell proliferation at G0/G1 phase. The results obtained from antitumor in vivo indicate that Ir1 can significantly inhibit the growth of tumors with an inhibitory rate of 54.08%. The docking studies show that complexes Ir1-3 interact with DNA through minor-groove intercalation, which increases the distance of DNA base pairs, leading to a change of DNA helix structure. These experimental and theoretical findings indicate that complexes Ir1-3 can induce apoptosis in SGC-7901 cells through the mitochondrial dysfunction and DNA damage pathways, and then exerting anti-tumor activity in vitro and vivo.

Two new monofunctional platinum(II) dithiocarbamate complexes: phenanthriplatin-type axial protection, equatorial-axial conformational isomerism, and anticancer and DNA binding studies

The syntheses of two platinum(ii) dithiocarbamate complexes (1 and 2) that show quinoplatin- and phenanthriplatin-type axial protection of the Pt-plane are described. The Pt-plane of complex 2 is axially more protected than that of complex 1. Furthermore, both complexes adopt two different stereochemical conformations in the solid state (based on single-crystal X-ray structures) owing to the structurally flexible piperazine backbone; i.e., C-e,e-Anti (1) and C-e,a-Syn (2), where "C" stands for the chair configuration, "e" and "a" stand for the equatorial and axial positions and "Anti" (opposite side) and "Syn" (same side) represent the relative orientations in space of the terminal substituents on the piperazine ring. In complex 2, the C-e,a-Syn conformation may provide additional steric hindrance to the Pt-plane. Despite the lower lipophilicity of 2 as compared to that of 1, the in vitro anticancer action against selected cancer cell lines is better for the former revealing the superior role of the axial protection over lipophilicity in modulating anticancer activity. The activity against the cancer promoting protein NF-κB signifies that the mode of cancer cell death may be the result of hindering the activity of NF-κB in the initiation of apoptosis. The apoptotic mode of cell death has been established earlier in a study using Annexin V-FITC. Finally, DNA binding studies revealed that the complex-DNA adduct formation is spontaneous and the mode of interaction is non-intercalative (electrostatic/covalent).

A novel palladium(II) antitumor agent: Synthesis, characterization, DFT perspective, CT-DNA and BSA interaction studies via in-vitro and in-silico approaches

Since numerous people annually pass away due to cancer, research in this field is essential. Thus a newly made and water like palladium(II) complex of formula [Pd(phen)(acac)]NO3, where phen is 1,10-phenanthroline and acac is acetylacetonato ligand, has been synthesized by the reaction between [Pd(phen)(H2O)2](NO3)2 and sodium salt of acetylacetone in the molar ratio of 1:1. It has been structurally characterized via the methods such as conductivity measurement, elemental analysis and spectroscopic methods (FT-IR, UV-Vis and 1H NMR). The geometry optimization of this complex at the DFT level of theory reveals that Pd(II) atom is situated in a square-planar geometry. The complex has been screened for its antitumor activity against K562 cancer cells which demonstrated efficacious activity. The interaction of above palladium(II) complex with CT-DNA as a target molecule for antitumor agents and BSA as a transport protein was studies by a variety of techniques. The results of UV-Vis absorption and fluorescence emission indicated that the Pd(II) complex interacts with EB + CT-DNA through hydrophobic and with BSA by hydrogen bonding and van der Waals forces at very low concentrations. In these processes, the fluorescence quenching mechanism of both the macromolecules seems to be the combined dynamic and static. The interaction was further supported for CT-DNA by carrying out the gel electrophoresis and viscosity measurement and for BSA by the circular dichroism and Förster resonance energy transfer experiments. Furthermore, results of partition coefficient determination showed that the [Pd(phen)(acac)]NO3 complex is more lipophilic than that of cisplatin. Moreover, molecular docking simulation confirms the obtained results from experimental tests and reveals that the complex tends to be located at the intercalation site of DNA and Sudlow's site I of BSA.

Zn(ii), Cd(ii) and Hg(ii) saccharinate complexes with 2,6-bis(2-benzimidazolyl)pyridine as promising anticancer agents in breast and lung cancer cell lines via ROS-induced apoptosis

New Zn(ii), Cd(ii) and Hg(ii) complexes of saccharinate (sac) and 2,6-bis(2-benzimidazolyl)pyridine (bzimpy), [Zn(bzimpy)2](sac)2·2H2O (Zn), [Cd(sac)2(bzimpy)] (Cd) and [Hg(sac)2(bzimpy)] (Hg), were prepared and fully characterized by spectroscopic methods and X-ray crystallography. In vitro anticancer screening in A549 (lung), MCF-7 (breast) and HT29 (colon) cell lines showed that Zn was highly cytotoxic against A549 and MCF-7 cells with IC50 values of 1.74 ± 0.06 and 3.15 ± 0.10 μM, respectively, and Hg demonstrated potent cytotoxic activity in MCF-7 cells (8.61 ± 0.98 μM), while Cd and bzimpy exhibited moderate growth inhibitory activities in all of the cell lines. In addition, they showed significantly lower toxicity towards normal human breast epithelial MCF10A cells. Moreover, the complexes exhibited significantly high nuclease activity towards plasmid DNA and their interactions with DNA were assessed by gel electrophoresis and DNA docking. Zn and Hg induced G0/G1 cell arrest and apoptotic cell death detected via typical DNA condensation/fragmentation, annexin V staining and caspase 3/7 activity in A549 and MCF-7 cells. These complexes further caused depolarization of mitochondria and oxidative damage of genomic DNA following excessive production of reactive oxygen species (ROS).

Synthesis, characterization and crystal structures of platinum(II) saccharinate complexes with 1,5-cyclooctadiene

Two new platinum(II) complexes, namely [PtCl(sac)(COD)] (1) and [Pt(sac)₂(COD)] (2) (sac = saccharinate and COD = 1,5-cyclooctadiene), were synthesized and characterized by elemental analysis, IR, NMR, ESI-MS spectroscopic and thermal analysis (TG/DTA) methods. The platinum(II) complexes were prepared from the reaction of [PtCl₂(COD)] with Na(sac)•2H₂O. The addition of the sac ligand resulted in the replacement of 1 and 2 chlorido ligands in [PtCl₂(COD)] to yield 1 and 2, respectively. The structures of the complexes were determined by single crystal X-ray diffraction and showed a distorted square planar coordination geometry around platinum(II). COD acted as a π-donor ligand, while sac was N -coordinated in both complexes. The TG/DTA data indicated that both complexes were thermally stable up to 220 °C in air and their thermal decompositions yielded Pt as a final product. Complexes 1 and 2 were also designed as possible precursors to synthesize new mixed-ligand platinum(II) sac complexes in a one-pot reaction.

Synthesis and antitumor activities of transition metal complexes of a bis-Schiff base of 2-hydroxy-1-naphthalenecarboxaldehyde

The complexes of Schiff base have attracted much attention for their potential biological activities. In this research, five transition metal complexes TM₃L₂(OAc)₂ (TM = Cu, 1; Ni, 2; Co, 3; Mn, 4; Fe, 5) were prepared using a bis-Schiff base of N,N'-bis[(2-hydroxy-1-naphthalenyl)methylene]-propane-1,3-diamine (H₂L), which present similar linear trinuclear structures with their three metal ions consolidated by two bis-Schiff base ligands and two acetate ligands. Their antitumor activities in vitro were screened through seven human cancer cell lines by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. It revealed that complexes 1, 2 and 5 show much higher antitumor activities than the bis-Schiff base ligand and complexes 3 and 4, and even than cisplatin. Among them, complex 1 has the highest inhibitory effects on tumor cells with its IC₅₀ value (half-inhibitory concentration) being less than 0.5 μM for human bladder cancer cell line T-24, at which concentration complex 1 shows nearly no toxicity to the normal cell HL-7702 as revealed by flow cytometry. All of these demonstrate a potential anti-cancer candidate for complex 1, which induces tumor cell apoptosis by blocking T-24 tumor cells at the G2/M phase of the cell cycle, reducing mitochondrial membrane potential, increasing the concentration of reactive oxygen species and Ca²⁺ in the cell, and changing the expression of proteins.

Synthesis and cytotoxic activities of organometallic Ru(II) diamine complexes

A series of mono and bimetallic ruthenium(II) arene complexes bearing diamine (Ru_1-6) were prepared and fully characterized by ¹H, ¹³C, ¹⁹F, and ³¹P NMR spectroscopy and elemental analysis. The crystal structure of the bimetallic complex (Ru₅) was determined by X-ray crystallography. Monometallic analogues (Ru_1-3) were synthesized to investigate the contributions of ruthenium and the other organic groups (aren, ethylenediamine, butyl) to the activity. The electrochemical behaviors of mono and bimetallic complexes were obtained from the relationship between cyclic voltammetry (CV) and the biological activities of the compounds. The cytotoxic activities of the complexes (Ru_1-6) were tested against wide-scale cancer cell lines, namely HeLa, MDA-MB-231, DU-145, LNCaP, Hep-G2, Saos-2, PC-3, and MCF-7, and normal cell lines 3T3-L1 and Vero. Diamine Ru(II) arene complexes have unique biological characteristics and they are promising models for new anticancer drug development. MTT analysis reveals that each synthesized Ru complex showed cytotoxic activity towards the different cancer cells. In particular, three Ru complexes (Ru₃, Ru₅ and Ru₆) showed less toxic effects on the cancer cells than the others. These novel Ru complexes affected both cancer and normal cell lines. As they had a toxic effect on the cells, the dosage applied should be tested before being used for in vivo applications. Cytotoxicity tests have shown that the bimetallic complex Ru₆ was effective on all cancer cells. The effect of bimetallic enhancement on cancer cell lines, the systematic variation of the intermetallic distance and the ligand donor properties of the mono and bimetallic complexes were explored based on the cytotoxic activity. The interaction with FS-DNA and the stability/aquation of the complexes (Ru₃ and Ru₆) were investigated with ¹H NMR spectroscopy. The binding modes between the complexes (Ru₃ and Ru₆) and DNA were investigated via UV-Vis spectroscopy.

Two telomerase-targeting Pt(ii) complexes of jatrorrhizine and berberine derivatives induce apoptosis in human bladder tumor cells

Two novel Pt(ii) complexes, [Pt(B-TFA)Cl]Cl (Pt1) and [Pt(J-TFA)Cl]Cl (Pt2) with jatrorrhizine and berberine derivatives (B-TFA and J-TFA) were first prepared as desirable luminescent agents for cellular applications and potent telomerase inhibitors, which can induce bladder T-24 tumor cell apoptosis by targeting telomerase, together with induction of mitochondrial dysfunction, telomere DNA damage and cell-cycle arrest. Importantly, T-24 tumor inhibition rate (TIR) was 50.4% for Pt2, which was higher than that of Pt1 (26.4%) and cisplatin (37.1%). Taken together, all the results indicated that jatrorrhizine and berberine derivatives Pt1 and Pt2 show low toxicity and could be novel Pt-based anti-cancer drug candidates.

Novel nickel(II), palladium(II), and platinum(II) complexes having a pyrrolyl-iminophosphine (PNN) pincer: Synthesis, crystal structures, and cytotoxic activity

A pyrrolyl-iminophosphine (PNNH) which would act as a potential terdentate ligand has been prepared by Schiff base reaction. Complexes [M(PNN)X] (M = Ni; X = Cl (1), Pd; X = Cl (2), Br (3), I (4), M = Pt; X = Cl (5)) were prepared. The title complexes were characterized by various spectroscopic (IR, ¹H, ¹³C, and ³¹P NMR) and elemental analyses. The molecular structures of 1, 2, and 5 have been established by single-crystal X-ray crystallography, demonstrating a distorted square planar geometry comprising two 5-membered metallacyclic rings. Complexes 1 and 2 were found to crystallize in the orthorhombic while complex 5 crystallizes in the monoclinic. Cytotoxicities of the complexes along with PNNH were evaluated against A549 (lung), SK-OV-3 (ovarian), SM-MEL-2 (skin), and HCT15 (colon) human cancer cell lines by sulforhodamine B assay. Notably, the palladium(II) complex (2) shows the highest activity. Apoptosis activity along with the caspase inhibitor Z-VAD (Z-Val-Ala-Asp-fluoromethyl ketone) assay of 2 and 5 against A549 and HCT15 cancer cell lines were investigated to learn a mechanistic pathway for the observed cytotoxicity, practically eliminating an apoptotic cell-death route. Complexes 2 and 5 were studied to DNA cleavage assay and molecular docking simulation. The DNA (pcDNA3.0) cleavage experiment evaluates complex 5 interacting with DNA, more effectively, in comparison to complex 2. Molecular docking simulation of 2 and 5 toward DNA and GRP78 (glucose-regulated protein 78) was performed to predict binding sites of ligand-receptors and a plausible mechanistic aspect of metallodrug-action.

Pentafluorophenyl Platinum(II) Complexes of PTA and its N-Allyl and N-Benzyl Derivatives: Synthesis, Characterization and Biological Activity

From the well-known 1,3,5-triaza-phosphaadamantane (PTA, 1a), the novel N-allyl and N-benzyl tetrafuoroborate salts 1-allyl-1-azonia-3,5-diaza-7-phosphaadamantane (APTA(BF₄), 1b) and 1-benzyl-1-azonia-3,5-diaza-7-phosphaadamantane (BzPTA(BF₄), 1c) were obtained. These phosphines were then allowed to react with (Pt(μ-Cl)(C₆F₅)(tht))₂ (tht = tetrahydrothiophene) affording the water soluble Pt(II) complexes trans-(PtCl(C₆F₅)(PTA)₂) (2a) and its bis-cationic congeners trans-(PtCl(C₆F₅)(APTA)₂)(BF₄)₂ (2b) and trans-(PtCl(C₆F₅)(BzPTA)₂)(BF₄)₂ (2c). The compounds were fully characterized by multinuclear NMR, ESI-MS, elemental analysis and (for 2a) also by single crystal X-ray diffraction, which proved the trans configuration of the phosphine ligands. Furthermore, in order to evaluate the cytotoxic activities of all complexes the normal human dermal fibroblast (NHDF) cell culture were used. The antineoplastic activity of the investigated compounds was checked against the human lung carcinoma (A549), epithelioid cervix carcinoma (HeLa) and breast adenocarcinoma (MCF-7) cell cultures. Interactions between the complexes and human serum albumin (HSA) using fluorescence spectroscopy and circular dichroism spectroscopy (CD) were also investigated.

Iron(III) and nickel(II) complexes of tetradentate thiosemicarbazones: Synthesis, structure, cytotoxicity, and lipophilicity

Eighteen of the iron(III) and nickel(II) complexes with tetradentate thiosemicarbazidato ligands were synthesized and described, by analytical and spectroscopic methods. Two complexes as an example to the iron and nickel centered ones were crystallographically analyzed to confirm the molecular structures. Cytotoxic effects of the complexes on K562 chronic myeloid leukemia cells were determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. For comparison, human umbilical vein endothelial cells (HUVECs) was used as a noncancerous cell line. While four of the iron(III) complexes exhibited the antileukemic effect with 50% inhibition of cell growth (IC₅₀ ) values in the 3.4 to 6.9 μg/mL range on K562 cell line, the nickel(II) complexes showed no significant effect on both cell lines. The complexes Fe4, Fe5, and Fe6, bearing 4-methoxy substituent exhibited relatively high antiproliferative activity on both cell lines. Complex Fe3 with 3-methoxy and S-allyl groups exhibited a selectivity between K562 and HUVEC cells by IC₅₀ values of 6.9 and >10 μg/mL, respectively. Lipophilicity, a key parameter for bioavailability and oral administration, was found in the range of -0.3 and +1.3 that desired for drug active ingredients. The results were discussed in the context of a structure-activity relationship.

Structures and anticancer activity of chlorido platinum(II) saccharinate complexes with mono- and dialkylphenylphosphines

cis-[PtCl(sac)(PPh₂Me)₂] (1), cis-[PtCl(sac)(PPhMe₂)₂] (2), trans-[PtCl(sac)(PPh₂Et)₂] (3) and trans-[PtCl(sac)(PPhEt₂)₂] (4) complexes (sac = saccharinate) were synthesized and characterized by elemental analysis and spectroscopic methods. The structures of 2-4 were determined by X-ray single-crystal diffraction. The interaction of the complexes with DNA was studied various biochemical, biophysical and molecular docking methods. Only the cis-configured complexes (1 and 2) showed nuclease activity and their binding affinity towards DNA was considerably higher than those of their trans-congeners (3 and 4). The chlorido ligand in the cis-configured complexes underwent aquation, making them more reactive towards DNA. Furthermore, 1 and 2 exhibited anticancer potency on breast (MCF-7) and colon (HCT116) cancer cells similar to cisplatin, whereas 3 and 4 were biologicallly inactive. Mechanistic studies on MCF-7 cells showed that higher nuclear uptake, cell cycle arrest at the S phase, dramatically increased DNA double-strand breaks, apoptosis induction, elevated levels of reactive oxygen species (ROS) and high mitochondrial membrane depolarization greatly contribute to the anticancer potency of 1 and 2.

In vitro and in vivo activity of novel platinum(ii) complexes with naphthalene imide derivatives inhibiting human non-small cell lung cancer cells

3 induced NCI-H460 cell apoptosis via inhibition of the telomerase and dysfunction of mitochondria. Remarkably, 3 obviously inhibited NCI-H460 xenograft tumor growth in vivo.

Structure and anticancer activities of four Cu(ii) complexes bearing tropolone

The title Cu(ii) complexes of tropolone induce the apoptosis of MGC80-3 through a caspase-dependent mitochondrion pathway and can also induce autophagy.

Palladium(ii) and platinum(ii) saccharinate complexes with bis(diphenylphosphino)methane/ethane: synthesis, S-phase arrest and ROS-mediated apoptosis in human colon cancer cells

New neutral [M(sac)2(diphos)] and cationic [M(diphos)2](sac)2 complexes, where M = PdII or PtII, sac = saccharinate, and diphos = 1,1-bis(diphenylphosphino)methane (dppm) or 1,2-bis(diphenylphosphino)ethane (dppe), were synthesized and structurally characterized. The anticancer activity of the complexes was investigated against MCF-7 (breast), A549 (lung), HCT116 (colon), DU145 (prostate) cancer and BEAS-2B (normal bronchial epithelial) cells. Neutral Pt-dppm (2) and Pd-dppe complexes (5) did not show any biological activity. The cationic Pd-dppe (7) complex displayed antiproliferative activity, while the rest of the complexes exhibited potent cytotoxicity compared with cisplatin. The active Pd(ii)/Pt(ii) complexes were then included in further studies including interaction with DNA/HSA, nuclease activity, cellular uptake and lipophilicity. The potent complexes induced the apoptotic cell death as probed through annexin V positivity and caspase activation. Mechanistic studies on HCT116 cells showed that the complexes cause cell cycle arrest at the DNA synthesis (S) phase and excessive generation of reactive oxygen species (ROS), damaging to both mitochondria and DNA.