Coumarin centered copper(ii) complex with appended-imidazole as cancer chemotherapeutic agents against lung cancer: molecular insight via DFT-based vibrational analysis

Chromophore appended DPA-based copper(II) complexes with a diimine motif towards DNA binding and fragmentation studies

Mixed ligand copper(II) complexes [Cu(L1)(bpy)](ClO4)21 and [Cu(L2)(bpy)](ClO4)22 (where L1 = 1-(anthracen-9-yl)-N,N-bis(pyridin-2-ylmethyl)methanamine, L2 = 1-(pyren-1-yl)-N,N-bis(pyridin-2-ylmethyl)methanamine and bpy = 2,2'-bipyridine) were synthesised and characterised thoroughly via different analytical and spectroscopic techniques i.e., UV-vis spectroscopy, fluorescence spectroscopy, FT-IR spectroscopy, HRMS and EPR spectroscopy. The molecular structures of the synthesised complexes were obtained using the single-crystal X-ray diffraction technique. Both complexes exhibited penta-coordinated and acquired distorted square pyramidal geometry. The redox behaviour of complexes 1 and 2 was investigated by employing cyclic voltammetry. The DNA binding study was carried out by UV-vis spectrophotometry using double-stranded salmon sperm DNA (ds-ss-DNA). The binding constant (Kb) values of 1 and 2 were 0.11 × 104 M-1 and 1.05 × 104 M-1, respectively, which indicates that 2 has better binding ability than 1. This might be due to the higher conjugative abilities with the extended surface area of the aromatic pyrene ring compared to the anthracene moiety. The fluorescence quenching experiments were also performed with EB bound DNA (EB-DNA) and Stern-Volmer constant (KSV) values were calculated as 1.23 × 105 M-1 and 1.39 × 105 M-1 for 1 and 2, respectively, suggesting that 2 showed stronger interaction with ss-DNA than 1. The molecular docking data support the DNA-binding studies, with the sites and mode of interactions against B-DNA varying with 1 and 2. Evaluation of the DNA binding properties of the complexes to linearized plasmid DNA indicated that 2 had modest DNA binding properties, which is a pre-requisite for a genotoxic agent. The effect of 1 and 2 on cell survival was analysed using HeLa cells by MTT assay and it was observed that the IC50 values of 1 and 2 were 43.7 μM and 18.6 μM, respectively. Our study paves the way for the designing of bio-inspired novel mixed metal complexes, which shows promising results for further exploration of molecular and mechanistic studies towards the development of non-platinum based economical metallodrugs.

Chrysin Encapsulated Copper Nanoparticles with Low Dose of Gamma Radiation Elicit Tumor Cell Death Through p38 MAPK/NF-κB Pathways

Improving radiation effect on tumor cells using radiosensitizers is gaining traction for improving chemoradiotherapy. This study aimed to evaluate copper nanoparticles (CuNPs) synthesized using chrysin as radiosensitizer with γ-radiation on biochemical and histopathological approaches in mice bearing Ehrlich solid tumor. CuNPs were characterized with irregular round sharp shape with size range of 21.19-70.79 nm and plasmon absorption at 273 nm. In vitro study on MCF-7 cells detected cytotoxic effect of CuNPs with IC50 of 57.2 ± 3.1 μg. In vivo study was performed on mice transplanted with Ehrlich solid tumor (EC). Mice were injected with CuNPs (0.67 mg/kg body weight) and/or exposed to low dose of gamma radiation (0.5 Gy). EC mice exposed to combined treatment of CuNPs and radiation showed a marked reduction in tumor volume, ALT and CAT, creatinine, calcium, and GSH, along with elevation in MDA, caspase-3 in parallel with inhibition of NF-κB, p38 MAPK, and cyclin D1 gene expression. Comparing histopathological findings of treatment groups ends that combined treatment was of higher efficacy, showing tumor tissue regression and increase in apoptotic cells. In conclusion, CuNPs with a low dose of gamma radiation showed more powerful ability for tumor suppression via promoting oxidative state, stimulating apoptosis, and inhibiting proliferation pathway through p38MAPK/NF-κB and cyclinD1.

Therapeutic effects of medicinal plants and their constituents on lung cancer, in vitro, in vivo and clinical evidence

The most common type of cancer in the world is lung cancer. Traditional treatments have an important role in cancer therapy. In the present review, the most recent findings on the effects of medicinal plants and their constituents or natural products (NP) in treating lung cancer are discussed. Empirical studies until the end of March 2022 were searched using the appropriate keywords through the databases PubMed, Science Direct and Scopus. The extracts and essential oils tested were all shown to effect lung cancer by several mechanisms including decreased tumour weight and volume, cell viability and modulation of cytokine. Some plant constituents increased expression of apoptotic proteins, the proportion of cells in the G2/M phase and subG0/G1 phase, and Cyt c levels. Also, natural products (NP) activate apoptotic pathways in lung cancer cell including p-JNK, Akt/mTOR, PI3/ AKT\ and Bax, Bcl2, but suppressed AXL phosphorylation. Plant-derived substances altered the cell morphology, reduced cell migration and metastasis, oxidative marker production, p-eIF2α and GRP78, IgG, IgM levels and reduced leukocyte counts, LDH, GGT, 5'NT and carcinoembryonic antigen (CEA). Therefore, medicinal plant extracts and their constituents could have promising therapeutic value for lung cancer, especially if used in combination with ordinary anti-cancer drugs.

Comprehensive Insights into Medicinal Research on Imidazole-Based Supramolecular Complexes

The electron-rich five-membered aromatic aza-heterocyclic imidazole, which contains two nitrogen atoms, is an important functional fragment widely present in a large number of biomolecules and medicinal drugs; its unique structure is beneficial to easily bind with various inorganic or organic ions and molecules through noncovalent interactions to form a variety of supramolecular complexes with broad medicinal potential, which is being paid an increasing amount of attention regarding more and more contributions to imidazole-based supramolecular complexes for possible medicinal application. This work gives systematical and comprehensive insights into medicinal research on imidazole-based supramolecular complexes, including anticancer, antibacterial, antifungal, antiparasitic, antidiabetic, antihypertensive, and anti-inflammatory aspects as well as ion receptors, imaging agents, and pathologic probes. The new trend of the foreseeable research in the near future toward imidazole-based supramolecular medicinal chemistry is also prospected. It is hoped that this work provides beneficial help for the rational design of imidazole-based drug molecules and supramolecular medicinal agents and more effective diagnostic agents and pathological probes.

Synthesis, Biophysical Interaction of DNA/BSA, Equilibrium and Stopped-Flow Kinetic Studies, and Biological Evaluation of bis(2-Picolyl)amine-Based Nickel(II) Complex

Reaction of bis(2-picolyl)amine (BPA) with Ni(II) salt yielded [(BPA)NiCl2(H2O)] (NiBPA). The Ni(II) in NiBPA bound to a BPA ligand, two chloride, and one aqua ligands. Because most medications inhibit biological processes by binding to a specific protein, the stopped-flow technique was used to investigate DNA/protein binding in-vitro, and a mechanism was proposed. NiBPA binds to DNA/protein more strongly than BPA via a static quenching mechanism. Using the stopped-flow technique, a mechanism was proposed. BSA interacts with BPA via a fast reversible step followed by a slow irreversible step, whereas NiBPA interacts via two reversible steps. DNA, on the other hand, binds to BPA and NiBPA via the same mechanism through two reversible steps. Although BSA interacts with NiBPA much faster, NiBPA has a much higher affinity for DNA (2077 M) than BSA (30.3 M). Compared to NiBPA, BPA was found to form a more stable BSA complex. When BPA and NiBPA bind to DNA, the Ni(II) center was found to influence the rate but not the mechanism, whereas, for BSA, the Ni(II) center was found to change both the mechanism and the rate. Additionally, NiBPA exhibited significant cytotoxicity and antibacterial activity, which is consistent with the binding constants but not the kinetic stability. This shows that in our situation, biological activity is significantly more influenced by binding constants than by kinetic stability. Due to its selectivity and cytotoxic activity, complex NiBPA is anticipated to be used in medicine.

Comprehensive Review on Medicinal Applications of Coumarin-Derived Imine–Metal Complexes

Coumarins are fused six-membered oxygen-containing benzoheterocycles that join two synthetically useful rings: α-pyrone and benzene. A survey of the literature shows that coumarins and their metal complexes have received great interest from synthetic chemists, medicinal scientists, and pharmacists due to their wide spectrum of biological applications. For instance, coumarin and its derivatives have been used as precursors to prepare a large variety of medicinal agents. Likewise, coumarin-derived imine–metal complexes have been found to display a variety of therapeutic applications, such as antibacterial, antifungal, anticancer, antioxidant, anthelmintic, pesticidal, and nematocidal activities. This review highlights the current synthetic methodologies and known bioactivities of coumarin-derived imine–metal complexes that make this molecule a more attractive scaffold for the discovery of newer drugs.

Unraveling the binding mechanism of an Oxovanadium(IV) - Curcumin complex on albumin, DNA and DNA gyrase by in vitro and in silico studies and evaluation of its hemocompatibility

An oxovanadium(IV) - curcumin based complex, viz. [VO(cur)(2,2´-bipy)(H₂O)] where cur is curcumin and bipy is bipyridine, previously synthesized, has been studied for interaction with albumin and DNA. Fluorescence emission spectroscopy was used to evaluate the interaction of the complex with bovine serum albumin (BSA) and the BSA-binding constant (K_b) was calculated to be 2.56 x 10⁵ M^-1, whereas a single great-affinity binding site was revealed. Moreover, the hemocompatibility test demonstrated that the complex presented low hemolytic fraction (mostly below 1%), in all concentrations tested (0-250 μΜ of complex, 5% DMSO) assuring a safe application in interaction with blood. The binding of the complex to DNA was also investigated using absorption, fluorescence, and viscometry methods indicating a binding through a minor groove mode. From competitive studies with ethidium bromide the apparent binding constant value to DNA was estimated to be 4.82 x 10⁶ M^-1. Stern-Volmer quenching phenomenon gave a Κ_SV constant [1.92 (± 0.05) x 10⁴ M^-1] and k_q constant [8.33 (± 0.2) x 10¹¹ M^-1s^-1]. Molecular docking simulations on the crystal structure of BSA, calf thymus DNA, and DNA gyrase, as well as pharmacophore analysis for BSA target, were also employed to study in silico the ability of [VO(cur)(2,2´-bipy)(H₂O)] to bind to these target bio-macromolecules and explain the observed in vitro activity.

A novel biocompatible formate bridged 1D-Cu(ii) coordination polymer induces apoptosis selectively in human lung adenocarcinoma (A549) cells

Copper compounds are promising candidates for next-generation metal anticancer drugs. Therefore, we synthesized and characterized a formate bridged 1D coordination polymer [Cu(L)(HCOO)₂]_n, (L = 2-methoxy-6-methyl-3-((quinolin-8-ylimino)methyl)chroman-4-ol), PCU1, wherein the Cu(ii) center adopts a square pyramidal coordination environment with adjacent CuCu distances of 5.28 Å. Primarily, in vitro DNA interaction studies revealed a metallopolymer which possesses high DNA binding propensity and cleaves DNA via the oxidative pathway. We further analysed its potential on cancerous cells MCF-7, HeLa, A549, and two non-tumorigenic cells HEK293 and HBE. The selective cytotoxicity potential of PCU1 against A549 cells driven us to examine the mechanistic pathways comprehensively by carrying out various assays viz, cell cycle arrest, Annexin V-FTIC/PI assay, autophagy, intercellular localization, mitochondrial membrane potential 'MMP', antiproliferative assay, and gene expression of TGF-β and MMP-2.

Biochemical pathways of copper complexes: progress over the past 5 years

Copper is an essential trace element with vital roles in many metalloenzymes; it is also prominent among nonplatinum anticancer metallodrugs. Copper-based complexes are endogenously biocompatible, tenfold more potent than cisplatin, exhibit fewer adverse effects, and have a wide therapeutic window. In cancer biology, copper acts as an antitumor agent by inhibiting cancer via multiple pathways. Herein, we present an overview of advances in copper complexes as 'lead' antitumor drug candidates, and in understanding their biochemical and pharmacological pathways over the past 5 years. This review will help to develop more efficacious therapeutics to improve clinical outcomes for cancer treatments.

Organometallic ruthenium (η6-p-cymene) complexes interfering with quorum sensing and biofilm formation: an anti-infective approach to combat multidrug-resistance in bacteria

Organometallic ruthenium complexes of flavonoids as antiquorum sensing agents against pathogens likeChromobacterium violaceumATCC 12472,Pseudomonas aeruginosaPAO1 and methicillin-resistantS. aureus(MRSA).

Tracking the dissolution-recrystallization structural transformation (DRST) of copper(II) complexes: a combined crystallographic, mass spectrometric and DFT study

Methanol- and temperature-induced dissolution-recrystallization structural transformation (DRST) was observed among two novel Cu^II complexes. This is first time that the combination of X-ray crystallography, mass spectrometry and density functional theory (DFT) theoretical calculations has been used to describe the fragmentation and recombination of a mononuclear Cu^II complex at 60 °C in methanol to obtain a binuclear copper(II) complex. Combining time-dependent high-resolution electrospray mass spectrometry, we propose a possible mechanism for the conversion of bis(8-methoxyquinoline-κ²N,O)bis(thiocyanato-κN)copper(II), [Cu(NCS)₂(C₁₀H₉NO)₂], Cu1, to di-μ-methanolato-κ⁴O:O-bis[(8-methoxyquinoline-κ²N,O)(thiocyanato-κN)copper(II)], [Cu₂(CH₃O)₂(NCS)₂(C₁₀H₉NO)₂], Cu2, viz. [Cu(SCN)₂(L)₂] (Cu1) → [Cu(L)₂] → [Cu(L)]/L → [Cu₂(CH₃O)₂(NCS)₂(L)₂] (Cu2). We screened the antitumour activities of L (8-methoxyquinoline), Cu1 and Cu2 and found that the antiproliferative effect of Cu2 on some tumour cells was much greater than that of L and Cu1.

Influence of DMβCD on the Interaction of Copper(II) Complex of 6-Hydroxychromone-3-carbaldehyde-3-hydroxybenzoylhydrazine with ctDNA

The interaction mechanism between a scarcely soluble copper(II) complex of Cu(II)-6-hydroxychromone-3-carbaldehyde-(3'-hydroxy)benzoylhydrazone (CuCHz) in aqueous solution and its DMβCD complex was studied in the presence of ctDNA through spectroscopy and thermodynamic methods. The thermodynamic results indicate that the binding process of the CuCHz-DMβCD inclusion complex is a spontaneous process and the inclusion is enthalpy-driven. The binding constants of CuCHz and CuCHz-DMβCD with ctDNA are 2.69 × 10³ and 14.7 × 10³ L mol^-1, respectively. The stoichiometry of the complex is 1:1, and the determined thermodynamic indicates that the process of binding is spontaneous and entropy-driven. A competitive binding titration with ethidium bromide revealed that CuCHz efficiently displaces EB from the EB-DNA system. In addition to the thermal denaturation experiments and docking studies, we can confirm that the mode of binding of this complex to ctDNA is intercalation mode. The presence of DMβCD enhances the aqueous solubility of CuCHz; nevertheless, the cyclodextrin did not affect the interaction of CuCHz with ctDNA because the inclusion complex breaks down when it binds with ctDNA.

Green synthesis and structural classification of Acacia nilotica mediated-silver doped titanium oxide (Ag/TiO2) spherical nanoparticles: Assessment of its antimicrobial and anticancer activity

Current exanimation reports, green fabrication of silver doped TiO2 nanoparticles (Ag/TiO2) using aqueous extract of Acacia nilotica as bio-reductant and assess its potential as antimicrobial and anticancer agent. The obtained spherical Ag/TiO2 were characterized by various analytical techniques including FTIR, (XRD), (FE-SEM EDS), and (TEM). Synthesized Ag/TiO2 demonstrated broad spectrum antibacterial and anticandidal activity. The order of antimicrobial activity was found to be E. coli > C. albicans > MRSA > P. aeruginosa. In addition, cytotoxicity and oxidative stress of Ag/TiO2 nanoparticles in (MCF-7) cells was also investigated. Outcomes of MTT assay showed concentration dependent reduction in cell viability. Further, synthesized NPs reduced the level of glutathione, induced ROS generation and lipid peroxidation in the treated cells. Therefore, it is envisaged that these spherical nanoparticles may be exploited in drug delivery, pharmaceutical, and food industry.

The crystal structure of aqua-bis(3-acetyl-2-oxo-2H-chromen-4-olato-κ2 O,O′)zinc(II) monohydrate, C22H18O10Zn

C22H18O10Zn, triclinic, P1̄ (no. 2), a = 7.9616(3) Å, b = 9.5386(3) Å, c = 14.2569(4) Å, α = 81.713(3)°, β = 82.724(3)°, γ = 73.103(3)°, V = 1021.03(6) Å3, Z = 2, R gt(F) = 0.0223, wR ref(F 2) = 0.0603, T = 295(2) K.

Synthesis and characterization of heterobimetallic SnIV-CuII/ZnII complexes: DFT studies, cleavage potential and cytotoxic activity

Heterobimetallic complexes [Cu(L)Sn(CH₃)₂(H₂O)(Cl)] (3) and [Zn(L)Sn(CH₃)₂(H₂O)(Cl)] (4) have been synthesized from their monometallic analogs [Cu(L)(H₂O)(Cl)] (1) and [Zn(L)(H₂O)(Cl)] (2) of Schiff base ligand (L) which were characterized by various spectroscopic and analytical methods. DFT calculations were carried out to simulate the vibrational spectra to support the anticipated structures. The interaction studies of ligand (L) and complexes (1-4) with CT-DNA were performed by employing UV-vis, and fluorescence spectroscopic techniques which revealed that heterobimetallic complexes 3 and 4 showed higher affinity with DNA due to dual mode of action as compared to monometallic complexes 1 and 2. Further, validation of the interaction studies was accomplished by carrying out molecular docking studies with DNA. Gel assay displayed that both the complexes have ability to cleave DNA efficiently and are specific minor groove binders. Cu^II-Sn^IV complex 3 cleaved pBR322 DNA via oxidative mechanism, while Zn^II-Sn^IV complex 4 followed hydrolytic cleavage pathway. In vitro cytotoxicity evaluation of complex 3 was tested on a different cancer cell lines showing promising antitumor activity.Communicated by Ramaswamy H. Sarma.

Copper(II) complexes as potential anticancer and Nonsteroidal anti-inflammatory agents: In vitro and in vivo studies

Copper-based compounds are promising entities for target-specific next-generation anticancer and NSAIDS therapeutics. In lieu of this, benzimidazole scaffold plays an important role, because of their wide variety of potential functionalizations and coordination modes. Herein, we report three copper complexes 1-3 with benzimidazole-derived scaffolds, a biocompatible molecule, and secondary ligands viz, 1-10-phenanthroline and 2,2'-bipyridyl. All the copper complexes have been designed, synthesized and adequately characterized using various spectroscopic techniques. In-vitro, human serum albumin (HSA) binding was also carried out using fluorescence technique and in-silico molecular modeling studies, which exhibited significant binding affinities of the complexes with HSA. Furthermore, copper complexes 1-3 were tested for biological studies, i.e., anticancer as well as NSAIDS. In vitro cytotoxicity results were carried out on cultured MCF-7 cell lines. To get the insight over the mechanism of action, GSH depletion and change in lipid peroxidation were tested and thus confirmed the role of ROS generation, responsible for the cytotoxicity of the complexes 1-3. Moreover, the copper complexes 1-3 were tested for potential to act as NSAIDS on albino rats and mice in animal studies in-vivo. Additionally, we also predicted the mechanism of action of the copper complexes 1-3 using molecular modeling studies with COX-2 inhibitor.

Thioether sulfur-bound [Cu2] complexes showing catechol oxidase activity and DNA cleaving behaviour

Ligand backbone alteration leads to different mechanisms for catecholase activity and order of interaction with DNA molecules.

Evaluation of (ɳ6-p-cymene) ruthenium diclofenac complex as anticancer chemotherapeutic agent: interaction with biomolecules, cytotoxicity assays

The designing of metal-based anticancer therapeutic agents can be optimized in a better and rapid way if the ligands utilized have standalone properties. Therefore, even when the organometallic/coordination complex (i.e., metallodrug) gets dissociated in extreme conditions, the ligand can endorse its biological properties. Herein, we have synthesized and characterized ɳ⁶-p-cymene ruthenium diclofenac complex. Furthermore, the ruthenium complex interactions with human serum albumin (HSA) and ct-DNA have been studied using various spectroscopic studies viz., UV, fluorescence, and circular dichroism and exhibited a significant binding propensity. Furthermore, in vitro cytotoxicity assays were carried out against human breast cancer "MCF-7" cell line. The ɳ⁶-p-cymene ruthenium diclofenac complex registered significant cytotoxicity with an IC₅₀ value of ∼25.0 µM which is comparable to the standard drugs. The ɳ⁶-p-cymene ruthenium diclofenac complex was able to decrease the MCF-7 cell proliferation and induced significant levels of apoptosis with relatively low toxicity.

Evaluation of Transition Metal Complexes of Benzimidazole-Derived Scaffold as Promising Anticancer Chemotherapeutics

Three new transition metal complexes, Cu(II) 1, Co(II) 2, and Zn(II) 3 with ligand “bimnap” derived from 1-methyl-2-aminobenzimidazole and 2-hydroxynapthaldehyde were synthesized and characterized. The structure of the ligand was determined by single X-ray crystallography. All the three complexes, 1⁻3, were examined for the mode of interaction with biomolecule viz., calf thymus-DNA (CT-DNA) using various spectroscopic methods. The nuclease activity was performed against pBR322 DNA that exhibited concentration-dependent degradation of the nucleic acid. The mechanism of DNA cleavage was studied by the electrophoretic pattern in the presence of the radical scavengers. Also, the complexes 1⁻3 were analyzed for groove binding affinity. Moreover, in vitro cytotoxicities of the complexes 1⁻3 were tested against the five human cancer cell lines, i.e., HeLa, SK-MEL-1, HepG2, HT108, and MDA-MB 231. Also, the cell adhesion and migration properties upon treatment of cell lines with complexes 1⁻3, and consequently, their cell death pathway via apoptosis and necrosis were analyzed. Further, complexes 1⁻3 were studied in vivo for their toxicities and tolerabilities in mice. In sum, the complexes 1⁻3 showed merits of an effective anticancer agent in cell lines⁻based study while minor side effects were observed in vivo.A green solvent extraction technology involving a microwave processing method was used to increase the content of minor ginsenosides from Panax notoginseng. This article aims to investigate the optimization of preparation of the minor ginsenosides by this microwave processing method using single-factor experiments and response surface methodology (RSM), and discuss the blood-enriching activity and hemostatic activity of the extract of microwave processed P. notoginseng (EMPN) The RSM for production of the minor ginsenosides was based on a three-factor and three-level Box-Behnken design. When the optimum conditions of microwave power, temperature and time were 495.03 W, 150.68 °C and 20.32 min, respectively, results predicted that the yield of total minor ginsenosides (Y₉) would be 93.13%. The actual value of Y₉ was very similar to the predicted value. In addition, the pharmacological results of EMPN in vivo showed that EMPN had the effect of enriching blood in N-acetylphenylhydrazine (APH) and cyclophosphamide (CTX)-induced blood deficient mice because of the increasing content of white blood cells (WBCs) and hemoglobin (HGB) in blood. Hemostatic activity in vitro of EMPN showed that it had significantly shortened the clotting time in PT testing (p < 0.05). The hemostatic effect of EMPN was mainly caused by its components of Rh₄, 20(S)-Rg₃ and 20(R)-Rg₃. This microwave processing method is simple and suitable to mass-produce the minor ginsenosides from P. notoginseng.

Design, Synthesis, and Biological Evaluation of Benzimidazole-Derived Biocompatible Copper(II) and Zinc(II) Complexes as Anticancer Chemotherapeutics

Herein, we have synthesized and characterized a new benzimidazole-derived “BnI” ligand and its copper(II) complex, [Cu(BnI)₂], 1, and zinc(II) complex, [Zn(BnI)₂], 2, using elemental analysis and various spectroscopic techniques. Interaction of complexes 1 and 2 with the biomolecules viz. HSA (human serum albumin) and DNA were studied using absorption titration, fluorescence techniques, and in silico molecular docking studies. The results exhibited the significant binding propensity of both complexes 1 and 2, but complex 1 showed more avid binding to HSA and DNA. Also, the nuclease activity of 1 and 2 was analyzed for pBR322 DNA, and the results obtained confirmed the potential of the complexes to cleave DNA. Moreover, the mechanistic pathway was studied in the presence of various radical scavengers, which revealed that ROS (reactive oxygen species) are responsible for the nuclease activity in complex 1, whereas in complex 2, the possibility of hydrolytic cleavage also exists. Furthermore, the cytotoxicity of the ligand and complexes 1 and 2 were studied on a panel of five different human cancer cells, namely: HepG2, SK-MEL-1, HT018, HeLa, and MDA-MB 231, and compared with the standard drug, cisplatin. The results are quite promising against MDA-MB 231 (breast cancer cell line of 1), with an IC₅₀ value that is nearly the same as the standard drug. Apoptosis was induced by complex 1 on MDA-MB 231 cells predominantly as studied by flow cytometry (FACS). The adhesion and migration of cancer cells were also examined upon treatment of complexes 1 and 2. Furthermore, the in vivo chronic toxicity profile of complexes 1 and 2 was also studied on all of the major organs of the mice, and found them to be less toxic. Thus, the results warrant further investigations of complex 1.

Carbohydrate-based heteronuclear complexes as topoisomerase Iα inhibitor: approach toward anticancer chemotherapeutics

Due to the critical role of cellular enzymes necessary for cell proliferation by deciphering topological hurdles in the process of DNA replication, topoisomerases have been one of the major targets in the anticancer drug development area. A need, therefore, arises for new metallodrugs that specifically recognizes DNA and inhibits the activity of topoisomerase enzymes, herein, we report the synthesis and characterization of new metal-based glycoconjugate entities containing heterobimetallic core Cu^II-Sn^IV (1) and Ni^II-Sn^IV (2) derived from N-glycoside ligand (L). The optimized structure of complex 1 and other significant vibrational modes have been explained using dispersion corrected B3LYP/DFT calculations. In vitro DNA binding profile of the L and both the complexes 1 and 2 were done by various biophysical studies. Complex 1 breaks pBR322 DNA via a hydrolytic means which was validated by T4 DNA enzymatic assay. To get a mechanistic insight of mode of action topoisomerase I (Topo I) inhibition assay was carried out. Also, we have taken the help of molecular modeling studies in accordance with experimental findings. In vitro cytotoxicity of the complex 1 was evaluated against a panel of cancer cells which exhibited remarkably good anticancer activity (GI₅₀ values <10 μg/ml). Moreover, intracellular localization of the complex 1 was visualized by confocal microscopy against HeLa cells.

In vitro cytotoxicity activity of novel Schiff base ligand-lanthanide complexes

A Schiff base ligand (SBL), N², N³-bis (anthracen-9-ylmethylene) pyridine-2, 3-diamine, was synthesized through the condensation of 2,6-diaminopyridine and anthracene-9-carbaldehyde using a 1:2 ratio. ¹H NMR spectra confirmed the observation of non-involvement aromatic carboxylic proton in SBL. A novel series of lanthanide (i.e., praseodymium (Pr), erbium (Er), and ytterbium (Yb))-based SBL metal complexes was successfully synthesized, and their functional groups were elaborately demonstrated using UV–visible, Fourier transform infrared (FT-IR), and fluorescence spectroscopy analyses. FT-IR spectral studies revealed that SBL behaved as a bidentate ligand and it was structured with metal ions by the two azomethine nitrogens. The synthesized SBL-based metal complexes were elaborately performed for cytotoxicity activity versus Vero, human breast cancer (MCF7), and cervical (HeLa) anticancer cell lines.

Design, synthesis and characterization of novel chromone based-copper(ii) antitumor agents with N,N-donor ligands: comparative DNA/RNA binding profile and cytotoxicity

A series of new chromone based-Cu(ii) complexes 1–3 derived from bioactive pharmacophore, 3-formylchromone and N,N-donor ligands viz., 1,10-phenanthroline, 2,2′-bipyridine and 1R,2R-DACH were synthesized as potential antitumor agents and thoroughly characterized by UV-vis, FT-IR, EPR, ESI-MS and elemental analysis. Single X-crystal diffraction studies of complex 2 revealed triclinic P1̄ space group with square pyramidal geometry around the Cu(ii) center. Comparative in vitro binding studies with ct-DNA and tRNA were carried out using absorption and emission titration experiments which revealed intercalative mode of binding with higher binding propensity of complexes 1–3 towards tRNA as compared to ct-DNA. Additionally, complex 1 exhibited high binding affinity among all the three complexes due to the involvement of phen co-ligands via π-stacking interactions in between nucleic acid base pairs. Furthermore, Hirshfeld surface analysis was carried out for complex 2 to investigate various intra and intermolecular non-covalent interactions (H-bonding, C–H⋯π etc.) accountable for stabilization of crystal lattice. The cleavage activity of complex 1 was performed by gel electrophoretic assay with pBR322 DNA and tRNA which revealed efficient DNA/tRNA cleaving ability of complex, suggesting tRNA cleavage both concentration and time dependent. Furthermore, in vitro cytotoxic activity of complexes 1–3 on a selected panel of human cancer cell lines was performed which revealed that all three complexes exhibited remarkably good cytotoxic activity with GI₅₀ value < 10 μg mL⁻¹ (<20 μM).

New chromone-based Cu(ii) tRNA targeted complexes 1–3 as potential anticancer agents have been synthesized and thoroughly characterized.

Copper(i) complexes with phosphine derived from sparfloxacin. Part III: multifaceted cell death and preliminary study of liposomal formulation of selected copper(i) complexes

Apoptosis induced by copper(i) complexes is connected to caspase-dependent mitochondrial pathways supported by ROS production and irreversible DNA fragmentation.