Homo- and heterometallic complexes of Zn(II), {Zn(II)Au(I)}, and {Zn(II)Ag(I)} with pentadentate Schiff base ligands as promising anticancer agents

Two families of homo- and heterometallic complexes, [Zn2L1(μ-OH)(H2O)2](ClO4)2, [Zn2L2(μ-OH)(H2O)2](ClO4)2, [Zn2L3(μ-OH)(H2O)2](ClO4)2, 1∞[{L1Zn2(μ-OH)}{μ-[Ag(CN)2]}](ClO4), [{L1Zn2(μ-OH)}2{μ-[Au(CN)2]}{[Au(CN)2]2}](ClO4)·H2O, 1∞[{L2Zn2(μ3-OH)}2(H2O){μ-[Ag(CN)2]}](ClO4)3·THF·0.5MeOH, 1∞[{L2Zn2(μ3-OH)}2(H2O){μ-[Au(CN)2]}](ClO4)3·THF·H2O, and 1∞[{L3Zn2(μ-OH)}{μ-[Ag(CN)2]}][Ag(CN)2]·H2O, respectively, have been synthesized and characterized. The Schiff bases used as ligands were obtained by condensation reactions of 2,6-diformyl-p-cresol with N,N-dimethyl-ethylenediamine (HL1), 2-aminomethyl-pyridine (HL2), and 2-aminoethyl-pyridine (HL3), respectively. The cytotoxic/cytostatic and genotoxic effects in cultured human MCF-7 (luminal type A breast cancer), MDA-MB-231 (triple negative breast cancer), HeLa (cervical carcinoma), and Lep-3 (non-tumor embryonal fibroblastoid cells) were studied. The investigations were performed by thiazolyl blue tetrazolium bromide test (MTT test), neutral red uptake cytotoxicity assay, crystal violet staining, hematoxylin and eosin staining, double staining with acridine orange and propidium iodide, AnnexinV/FITC, and Comet assay in short-term experiments (24-72 h, with monolayer cell cultures) as well as by 3D colony-forming method in long-term experiments (28 days, with 3D cancer cell colonies). The results obtained revealed that: (i) applied at a concentration range of 0.1-100 μg mL-1, the compounds investigated decrease in a time- and concentration-dependent manner the viability and/or proliferation of the treated cells; (ii) complexes of {Zn(II)Au(I)} show relatively higher cytotoxic/genotoxic activity and antitumor potential as compared to {Zn(II)Ag(I)}; (iii) some of the complexes demonstrate more pronounced cytotoxic potential than commercially available antitumor agents cisplatin, oxaliplatin, and epirubicin.

In vitro biological and in silico molecular docking and ADME studies of a substituted triazine-coordinated cadmium(II) ion: efficient cytotoxicity, apoptosis, genotoxicity, and nuclease-like activity plus binding affinity towards apoptosis-related proteins

A cadmium(II) complex containing dppt ligand with the formula [CdCl₂(dppt)₂], where dppt is 5,6-diphenyl-3-(2-pyridyl)-1,2,4-triazine was synthesized, elucidated and submitted to in vitro cytotoxicity studies against human breast (MCF-7), glioblastoma (U-87), and lung (A549) cancer cell lines as well as mouse embryo normal cell line (NIH/3T3), in comparison with cisplatin employing MTT assay over 24 and 48 h. The complex exhibited the highest cytotoxic effect against MCF-7 cells among the other three cell lines with IC₅₀ values of 8.7 ± 0.5 (24 h) and 1.2 ± 0.7 µM (48 h). Significantly, flow cytometric assessment of the complex-treated MCF-7 and U-87 cells demonstrated a dose-dependent induced apoptotic cell death. The cellular morphological changes were in concord with cytotoxicity and flow cytometric results. The results of comet assay showed that the complex is able to induce DNA damage in MCF-7 cells. These observations are of importance, as sustained damage to cellular DNA could lead to apoptotic cell death. The results of DNA-binding studies indicated that the complex fits into the DNA minor groove and interacts with DNA via a partial intercalation. Moreover, the complex was able to efficiently cleave pUC19 DNA through a hydrolytic mechanism. The binding affinity between the complex and apoptosis-relevant protein targets including APAF1, Bax, Bcl-2, Cas3, Cas7, and Cas9 was evaluated through molecular docking studies. In silico virtual studies revealed the complex's strong affinity towards apoptosis-related proteins; therefore the complex can act as a potential apoptosis inducer. Physicochemical, pharmacokinetics, lipophilicity, drug-likeness, and medicinal chemistry properties of the complex were also predicted through in silico absorption, distribution, metabolism and excretion studies.

Synthesis, characterization, biological properties, and molecular docking studies of new phosphoramide-based Ag(i) complexes

The effect of two new synthesized Ag(i) complexes on their biological properties was examined.

Metalo components exhibiting significant anticancer and antibacterial properties: a novel sandwich-type like polymeric structure

Four new dicyanoargentate(I)-based complexes 1-4 were synthesized from certain metal ions with a tetradentate ligand [N, N-bis (2-hydroxyethyl) -ethylenediamine; N-bishydeten] and determined by diverse procedures (elemental, thermal, FT-IR, ESI-MS for 1-3 and, magnetic susceptibility and EPR for 1, and 2) including crystal analysis of 4. The crystal method revealed that complex 4 has a sandwich-type like polymeric chemical structure with layers formed by [Cd(N-bishydeten)2]2+ cations and [Ag(CN)2]- anions. The complexes were further characterized by fluorescence and UV spectroscopy to determine their physicochemical features. The complexes displayed a DNA binding activity within the same range as found for cisplatin, in addition to their strong stability in the presence of the physiological buffer system. The complexes were also investigated for pharmacological properties like interaction with DNA/Bovine serum albumin, anticancer and antibacterial activities. Physicochemical studies of DNA with the complexes suggested that the interaction mode between them are possibly both intercalative and groove binding types. These spectroscopic measurements also show that there may be a binding tendency between BSA and the complexes via hydrogen or Van der Waals bonds. The viability tests demonstrated that all the complexes exhibited antibacterial (1-4) and anticancer effects (2-4) toward ten diverse bacterial strains and three tumor cells (HT-29 colon adenocarcinoma, HeLa cervical cancer, and C6 glioma), respectively.

Synthesis, characterization and anticancer activity in vitro evaluation of novel dicyanoaurate (I)-based complexes

Molecular structures containing gold, such as auranofin, have been extensively studied in the diagnosis and treatment of many diseases, including cancer treatment. The pharmacological properties of the newly synthesized unique gold-ligand structures have been reported for different cancer cell lines. However, findings on bishydeten-metal salt complexes with gold are rare. In this work, the synthesis of five novel cyanide-bridged coordination compounds having the closed formulae [Ni(bishydeten)][Au(CN)₂]₂ (1), [Cu(bishydeten)][Au(CN)₂]₂ (2), [Zn(bishydeten)₂Au₃(CN)₄][Au₂(CN)₃] (3), [Cd(bishydeten)_0,5]₂[Au(CN)₂]₄.2H₂O (4), and [Cd(bishydeten)₂][Au(CN)₂]₂ (5) (where bisyhdeten = N,N-bis(2-hydroxyethyl)ethylene diamine), and their characterization by elemental, infrared, ESI-MS, X-ray (for 2) and thermic measurement methods were performed. Complexes 1 and 3 are thermally more stable than the other three complexes. For these, pharmacological adequacies were also tested. The nucleic acid and protein binding affinities of the Au (I) compounds were also estimated by spectroscopic and electrophoretic techniques. Au (I) complexes were identified as strong chemotherapeutic with mild cytotoxicity, and they demonstrated a dose-dependent inhibition on the growth of cancer cells with IC50 at 0.11 to 0.47 μM. Investigation of mechanisms of action on cells revealed that Au (I) compounds managed to inhibit cell migration and led to a decrease in cytoskeletal proteins such as CK7 and CK20. However, Au (I) compounds failed to inhibit DNA topoisomerase I. Overall, and we suggest that potent antiproliferative activity, mild cytotoxicity, good solubility, and micromolar dosage of Au (I) compounds containing bisyhdeten-metal derivatives render them the potential focus of further studies as chemotherapeutic agents.

In vitro biological properties and predicted DNA–BSA interaction of three new dicyanidoargentate(i)-based complexes: synthesis and characterization

The synthesis, characterization and biological activity of three novel dicyanidoargentate(i)-based complexes are reported. The in vitro results show that these complexes may be potent antiproliferative drug candidates.

New bimetallic dicyanidoargentate(I)-based coordination compounds: Synthesis, characterization, biological activities and DNA-BSA binding affinities

Four compounds -two (2 and 3) completely new- of composition [Ni(edbea)Ag₃(CN)₅] (1), [Cu(edbea)Ag₂(CN)₄]·H₂O (2), [Cd(edbea)Ag₃(CN)₅]·H₂O (3) and [Cd(edbea)₂] [Ag(CN)₂]₂·H₂O (4) {edbea; 2,2'-(ethylenedioxy)bis (ethylamine)}, were synthesized and characterized using elemental, FT-IR, X-Ray (4), thermal, variable temperature magnetic measurement (1 and 2) and biological techniques. The DNA/BSA binding affinities of 2 and 3 were evaluated by UV-Vis spectrophotometric titrations, ethidium bromide exchange experiments and electrophoretic mobility measurements. Compounds 1 and 4 have previously been characterized and shown to reduce the proliferation and migration of tumor cells. For the sake of clarity, 1 precise mechanism of action on microbial organisms and temperature magnetic measurement were determined. The crystallographic analyses showed that 4 was built up of [Cd(edbea)₂]^II cations and [Ag₂(CN)₄]^II anions. Complexes demonstrated a remarkable antibacterial (1-4), antifungal (1-4) and antiproliferative activities (2 and 3) to ten human bacterial pathogens, four plant pathogenic fungi or three tumor cells (HeLa, HT29, and C6), respectively. Therefore, our results strongly confirm that cell proliferation, cell morphology, Bcl-2, P53 changes and apoptosis can be related to the pharmacological effects of the complexes as suitable candidate for clinical trials.

Synthesis and crystal structure of a cyanido-bridged copper(II)–silver(I) bimetallic complex containing a trimeric {[Ag(CN)2]−}3 anion, [Cu(Dach)2-Ag(CN)2-Cu(Dach)2][Ag(CN)2]3 (Dach=cis-1,2-diaminocyclohexane)

A new cyanido-bridged bimetallic copper(II)–silver(I) complex, [Cu(Dach)2-Ag(CN)2-Cu(Dach)2][Ag(CN)2]3 (1) (Dach=cis-1,2-diaminocyclohexane), has been prepared and characterized by IR spectroscopy and single crystal X-ray analysis. The crystal structure of complex 1 consists of a centrosymmetric trinuclear cation and three non-coordinated [Ag(CN)2]− ions assembled in the form of a trimer, {[Ag(CN)2]−}3. The complex ion is made up of two [Cu(Dach)2]2+ units connected by a bridging [Ag(CN)2]− anion. The copper atom in the complex ion assumes a distorted square pyramidal geometry with CN− nitrogen atoms occupying the apical position. The trinuclear units are joined by hydrogen bonding to form irregular chains.

Dicyanometallates as Model Extended Frameworks

We report the structures of eight new dicyanometallate frameworks containing molecular extra-framework cations. These systems include a number of hybrid inorganic–organic analogues of conventional ceramics, such as Ruddlesden–Popper phases and perovskites. The structure types adopted are rationalized in the broader context of all known dicyanometallate framework structures. We show that the structural diversity of this family can be understood in terms of (i) the charge and coordination preferences of the particular metal cation acting as framework node, and (ii) the size, shape, and extent of incorporation of extra-framework cations. In this way, we suggest that dicyanometallates form a particularly attractive model family of extended frameworks in which to explore the interplay between molecular degrees of freedom, framework topology, and supramolecular interactions.

Five novel dicyanidoaurate(i)-based complexes exhibiting significant biological activities: synthesis, characterization and three crystal structures

Herein the anticancer, antibacterial, and antifungal effects of the five novel dicyanidoaurate(i)-based complexes have been reported.