Synthesis, crystal structures and antitumor activity of two platinum(II) complexes with methyl hydrazinecarbodithioate derivatives of indolin-2-one

Piperazine-Based Co(III), Ni(II), Cu(II), and Zn(II) Carbodithioate Complexes as Potential Anticancer Agent

The development of facile and cost-effective anticancer metallodrugs possessing minimal side effects is urgently needed. Piperazine-containing anticancer drugs are already available on the market. A piperazine-based potassium 4-(ethoxycarbonyl)piperazine-1-carbodithioate [pecpcdt] (L) ligand and its metal complexes [Co(ecpcdt)3] (1), [Ni(ecpcdt)2] (2), [Cu(ecpcdt)2] (3), and [Zn(ecpcdt)2] (4) were synthesized. These compounds were characterized by different spectroscopic methods and single-crystal X-ray crystallography data. Ni(II) and Cu(II) complexes have distorted square planar geometry, whereas the Co(III) complex has distorted octahedral geometry around the metal ions. Complexes are weakly fluorescent in the solution compared to the free ligand. The complexes were further examined for their in vitro anticancer activities against the primary Dalton's lymphoma (DL) cells along with standard drug cisplatin. The anticancer studies of metal complexes have been performed through various biochemical assays, and the findings thus obtained suggest that they demonstrate an effective anticancer activity. [Co(ecpcdt)3] (1) shows superior cytotoxicity against DL cells than complexes [Cu(ecpcdt)2] (3), [Zn(ecpcdt)2] (4), and cisplatin. The superiority preferences of these complexes follows [Co(ecpcdt)3] (1) > [pecpcdt] > [Cu(ecpcdt)2] (3) > [Ni(ecpcdt)2] (2) > [Zn(ecpcdt)2] (4). Further assays were performed on a cobalt(III) complex having the highest efficacy to gain insights into the mechanism of cell death and showed that reduced mitochondrial membrane potential and increased mitochondrial ROS production, highlighting mitochondrial-dependent apoptosis as the major mechanism for tumor cell death. On the other hand, the viability of normal splenocytes was minimally affected by the [Co(ecpcdt)3] (1) treatment.

Structural Design, Anticancer Evaluation, and Molecular Docking of Newly Synthesized Ni(II) Complexes with ONS-Donor Dithiocarbazate Ligands

The current article reports the investigation of three new Ni(II) complexes with ONS-donor dithiocarbazate ligands: [Ni(L1)PPh3] (1), [Ni(L2)PPh3] (2), and [Ni(L2)Py] (3). Single-crystal X-ray analyses revealed mononuclear complexes with a distorted square planar geometry and the metal centers coordinated with a doubly deprotonated dithiocarbazate ligand and coligand pyridine or triphenylphosphine. The non-covalent interactions were investigated by the Hirshfeld surface and the results revealed that the strongest interactions were π⋅⋅⋅π stacking interactions and non-classical hydrogen bonds C-H···H and C-H···N. Physicochemical and spectroscopic methods indicate the same structures in the solid state and solution. The toxicity effects of the free ligands and Ni(II) complexes were tested on the human breast cancer cell line MCF-7 and non-malignant breast epithelial cell line MCF-10A. The half-maximal inhibitory concentration (IC50) values, indicating that the compounds were potent in inhibiting cell growth, were obtained for both cell lines at three distinct time points. While inhibitory effects were evident in both malignant and non-malignant cells, all three complexes demonstrated lower IC50 values for malignant breast cell lines than their non-malignant counterparts, suggesting a stronger impact on cancerous cell lines. Furthermore, molecular docking studies were performed showing the complex (2) as a promising candidate for further therapeutic exploration.

Mechanistic insight and structure activity relationship of isatin-based derivatives in development of anti-breast cancer agents

Breast cancer is most common in women and most difficult to manage that causes highest mortality and morbidity among all diseases and posing significant threat to mankind as well as burden on healthcare system. In 2020, 2.3 million women were diagnosed with breast cancer and it was responsible for 685,000 deaths globally, suggesting the severity of this disease. Apart from that, relapsing of cases and resistance among available anticancer drugs along with associated side effects making the situation even worse. Therefore, it is a global emergency to develop potent and safer antibreast cancer agents. Isatin is most versatile and flying one nucleus which is an integral competent and various anticancer agent in clinical practice and widely used by various research groups around the globe for development of novel, potent, and safer antibreast cancer agents. This review will shed light on the structural insights and antiproliferative potential of various isatin-based derivatives developed for targeting breast cancer in last three decades that will help researchers in design and development of novel, potent, and safer isatin-based antibreast cancer agents.

A review on the chemistry of novel platinum chelates based on azo-azomethine ligands

Numerous platinum group metals (PGMs) complexes contain azo-azomethine-based ligands. Azo-azomethine ligands are N-donor ligands that have extended conjugated π-bonded systems and both azo (–N=N–) and aldimine (–C=N–) functions in their structure. Plenty of platinum (Pt) complexes with azo-imine ligands have been prepared and characterized. Various multidentate azo-imine ligands coordinated with different platinum metal substrates afforded structurally diverse platinum chelates. Nonetheless, many azo-imine-based platinum complexes demonstrated a wide range of biological activities, photo-switchable properties, and redox activities. The review encompasses a general overview of platinum complexes with versatile azo-azomethine ligands, their synthetic protocol, spectroscopic and structural features, chemical reactivity, and multipurpose applications in different areas.

Spectroscopic Insight into Tetrahedrally Distorted Square Planar Copper(II) Complex: XRD/HSA, Physicochemical, DFT, and Thermal Investigations

The reaction of bidentate N-S-thione-Schiff base, (E)-benzyl 2-(1-(4-chlorophenyl)-ethylidene)hydrazinecarbodithioate, with Cu(NO3)2·3H2O produced a cis-Cu(II) complex. The molecular structure was confirmed and characterized by CHN-EA, FAB-MS, IR, and UV-Vis analyses. The XRD supported cis-isomer of the bis anionic bidentate N (azomethine) and S (thiol) ligand coordination mode in tetrahedrally distorted square planar, rarely reported in the literature. The results of the XRD-bond lengths were in perfect agreement with the density functional theory (DFT) calculation. DFT-calculated angles around the Cu(II) center displayed slightly less distortion around the metal center from those of XRD. Additionally, the thermal stability of the complex was evaluated via thermal gravimetric analysis (TGA). Two-dimensional fingerprint (2D-FP), Hirshfeld surface analysis (HSA), and molecular electrostatic potential (MEP) support the XRD-packing results with the existence of the H⸱⸱⸱Cl and CH⸱⸱⸱π bonds as the main interactions in the crystal lattice of the desired complex.

Synthesis, Characterization, and Anticancer Activity of Benzothiazole Aniline Derivatives and Their Platinum (II) Complexes as New Chemotherapy Agents

We describe the synthesis, characterization, molecular modeling, and in vitro anticancer activity of three benzothiazole aniline (BTA) ligands and their corresponding platinum (II) complexes. We designed the compounds based on the selective antitumor properties of BTA, along with three types of metallic centers, aiming to take advantage of the distinctive and synergistic activity of the complexes to develop anticancer agents. The compounds were characterized using nuclear magnetic resonance spectrometry, Fourier transform infrared spectroscopy, mass spectrometry, elemental analysis, and tested for antiproliferative activity against multiple normal and cancerous cell lines. L1, L2, and L1Pt had better cytotoxicity in the liver, breast, lung, prostate, kidney, and brain cells than clinically used cisplatin. Especially, L1 and L1Pt demonstrated selective inhibitory activities against liver cancer cells. Therefore, these compounds can be a promising alternative to the present chemotherapy drugs.

Bivalent Ni(II), Co(II) and Cu(II) complexes of [(E)-[(2-methyl-1,3-thiazol-5-yl)methylidene]amino]thiourea: synthesis, spectral characterization, DNA and in-vitro anti-bacterial studies

The present work describes the preparation of bivalent Ni(II), Co(II) and Cu(II) complexes of [(E)-[(2-methyl-1,3-thiazol-5-yl)methylidene]amino]thiourea (MTHC) by mixing in 1:2 ratio of corresponding metal salt and Schiff base ligand in ethanolic medium. The prepared ligand and its complexes are confirmed using elemental analysis, magnetic moments, FT-IR, NMR, electronic and ESR spectroscopy techniques. The spectroscopic data reveals that metal complexes are in square planar in nature. In DNA binding studies, the higher intrinsic binding constants (K_b) of Ni(II), Co(II) and Cu(II) complexes are 2.713 × 10⁶ M⁻¹, 5.529 × 10⁶ M⁻¹ and 2.950 × 10⁶ M⁻¹ respectively, evident that complexes are avid binder with DNA base pairs. The moderate anti-bacterial activity (in-vitro) against staphylococcus epidermidis, Bacillus subtilis, Pseudomonas aeruginosa and Escherichia coli bacterial culture may be due to the high electron density of ligand which prevents the charge reduction of metal ion. In the presence and absence of H₂O_2, it is notified that there is no appreciable DNA cleavage activity of Ni(II) and Co(II) complexes except Cu(II) complex which is due to aprotonation in the medium.

Revealing quinquennial anticancer journey of morpholine: A SAR based review

Morpholine, a six-membered heterocycle containing one nitrogen and one oxygen atom, is a moiety of great significance. It forms an important intermediate in many industrial and organic syntheses. Morpholine containing drugs are of high therapeutic value. Its wide array of pharmacological activity includes anti-diabetic, anti-emetic, growth stimulant, anti-depressant, bronchodilator and anticancer. Multi-drug resistance in cancer cases have emerged in the last few years and have led to the failure of many chemotherapeutic drugs. Newer treatment methods and drugs are being developed to overcome this problem. Target based drug discovery is an effective method to develop novel anticancer drugs. To develop newer drugs, previously reported work needs to be studied. Keeping this in mind, last five year's literature on morpholine used as anticancer agents has been reviewed and summarized in the paper herein.

Synthesis and biological evaluation of substituted 3-(2'-benzimidazolyl)coumarin platinum(II) complexes as new telomerase inhibitors

Eight new platinum(II) complexes Pt1-Pt8 with substituted 3‑(2'‑benzimidazolyl) coumarins were successfully synthesized and characterized by single crystal X-ray diffraction analysis, nuclear magnetic resonance spectroscopy (NMR), electrospray ionization-mass spectrometry (ESI-MS), infrared spectrophotometry (IR) and elemental analysis. Crystallographic data of these Pt1-Pt8 complexes showed that the Pt(II) has distorted four-coordinated square planar geometry. Pt1-Pt8 were found to display high cytotoxic activity in vitro against the cisplatin-resistant SK-OV-3/DDP cancer cells with a low IC₅₀ from 1.01-10.32 μM, but low cytotoxicity on the normal HL-7702 cells. Further studies revealed that Pt1-Pt3 induced apoptosis in SK-OV-3/DDP cancer cells via mitochondria dysfunction signaling pathways. Our findings also indicated that Pt1 was a telomerase inhibitor targeting c-myc promoter elements.

A novel series of pyrazole-platinum(II) complexes as potential anti-cancer agents that induce cell cycle arrest and apoptosis in breast cancer cells

Six novel compounds of platinum(II) with pyrazole derivatives PtPz1-PtPz6 were synthesised and characterised (PtPz1 - [Pt₂N-hydroksymethyl-3,5-dimethylpyrazole₄(berenil)₂]Cl₄; PtPz2 - [Pt₂3,5-dimethylpyrazole₄(berenil)₂]Cl₄; PtPz3 - [Pt₂3,4-dimethylpyrazole₄(berenil)₂]Cl₄; PtPz4 - [Pt₂pyrazole₄(berenil)₂]Cl₄; PtPz5- [Pt₂5-methylpyrazole₄(berenil)₂]Cl₄; PtPz6 - [Pt₂N-ethylpyrazole₄(berenil)₂]Cl₄). The cytotoxic activity of these complexes against MCF-7 and MDA-MB-231 breast cancer cell lines was determined using the MTT assay. Evaluation of apoptosis induction was done with the Annexin V-fluorescein isothiocyanate/propidium iodide assay. In addition, using a flow cytometer, we determined the influence of test compounds on the cell cycle and caspase-3, -8, and -9 activity. The obtained results of caspase activity were confirmed by cell imaging. Moreover, using the flow cytometer, the effects of the test compounds on mitochondrial potential change were assessed. The test results showed that novel pyrazole-platinum(II) complexes exhibited stronger anti-proliferative activity against two breast cancer cell lines than reference cisplatin. Compounds PtPz1, PtPz2, and PtPz3 with methyl substituents at the pyrazole ring showed stronger activity than pyrazole or ethylpyrazole containing complexes. Studies have shown that inhibition of cell survival occurs by arresting the G1 cell cycle and inducing apoptosis. Our analysis associated with the response of MCF-7 and MDA-MB-231 cells to treatment with PtPz1-PtPz6 showed that it leads the cells through the external and intrinsic (mitochondrial) apoptotic pathway via indirect DNA damage.

Crystal structure of tert-butyl (Z)-4-(2-(5-methoxy-3-(2-((methylthio)carbonothioyl)hydrazono)-2-oxoindolin-1-yl)ethyl)piperazine-1-carboxylate, C22H31N5O4S2

C22H31N5O4S2, triclinic, P1̅ (no. 2), a = 9.0366(1) Å, b = 10.3253(2) Å, c = 14.9997(2) Å, α = 72.790(1)°, β = 82.301(1)°, γ = 71.080(1)°, V = 1263.54(3) Å3, Z = 2, Rgt(F) = 0.0443, wRref(F2) = 0.1294, T = 271 K.

Crystal structure of methyl (Z)-2-(5-fluoro-2-oxoindolin-3-ylidene)hydrazine-1-carbodithioate, C10H8FN3OS2

C10H8FN3OS2, monoclinic, P21/c (no. 14), a = 6.2909(2) Å, b = 7.4103(2) Å, c = 24.7079(6) Å, β = 97.396(2)°, V = 1142.24(6) Å3, Z = 4, R gt(F) = 0.0375, wR ref(F 2) = 0.1014, T = 293 K.

Research progress in modern structure of platinum complexes

Since the antitumor activity of cisplatin was discovered in 1967 by Rosenberg, platinum-based anticancer drugs have played an important role in chemotherapy in clinic. Nevertheless, platinum anticancer drugs also have caused severe side effects and cross drug resistance which limited their applications. Therefore, a significant amount of efforts have been devoted to developing new platinum-based anticancer agents with equal or higher antitumor activity but lower toxicity. Until now, a large number of platinum-based complexes have been prepared and extensively investigated in vitro and in vivo. Among them, some platinum-based complexes revealing excellent anticancer activity showed the potential to be developed as novel type of anticancer agents. In this account, we present such platinum-based anticancer complexes which owning various types of ligands, such as, amine carrier ligands, leaving groups, reactive molecule, steric hindrance groups, non-covalently binding platinum (II) complexes, Platinum(IV) complexes and polynuclear platinum complexes. Overall, platinum-based anticancer complexes reported recently years upon modern structure are emphasized.