Half-Sandwich Cyclometalated RhIII Complexes Bearing Thiolate Ligands: Biomolecular Interactions and In Vitro and In Vivo Evaluations

A class of cyclometalated RhIII complexes [Cp*Rh(ppy)(SR)] bearing thiolate ligands, Cp* = pentamethylcyclopentadienyl, ppy = 2-phenylpyridinate, and R = pyridyl (Spy, 2), pyrimidyl (SpyN, 3), benzimidazolyl (Sbi, 4), and benzothiazolyl (Sbt, 5), were produced and identified by means of spectroscopic methods. The in vitro cytotoxicity of the RhIII compounds in three different human mortal cancerous cell lines (ovarian, SKOV3; breast, MCF-7; lung, A549) and a normal lung (MRC-5) cell line were evaluated, indicating the selectivity of these cyclometalated RhIII complexes to cancer cells. Complex 5, selected for in vivo experiment, has shown an effective inhibition of tumor growth in SKOV3 xenograft mouse model relative to control (p-values < 0.05 and < 0.01). Importantly, the outcomes of H&E (hematoxylin and eosin) staining and hematological analysis revealed negligible toxicity of 5 compared to cisplatin on a functioning of the main organs of mouse. Molecular docking, UV-vis, and emission spectroscopies (fluorescence, 3D fluorescence, synchronous) techniques were carried out on 1-5 to peruse the mechanism of the anticancer activities of these complexes. The obtained data help to manifest the binding affinity between the rhodium compounds and calf thymus DNA (CT-DNA) through the interaction by DNA minor groove and moderate binding affinity with bovine serum albumin (BSA), particularly with the cavity in the subdomain IIA. It can be concluded that the Rh-thiolate complexes are highly promising leads for the development of novel effective DNA-targeted anticancer drugs.

Half-lantern Cyclometalated Platinum(II) Complexes as Anticancer Agents: Molecular docking, Apoptosis, Cell Cycle Analysis and Cytotoxic Activity Evaluations

BACKGROUND AND OBJECTIVE

In the design of modern metal-based anticancer drugs, platinum-based complexes have gained growing interest. In this study, the anticancer activity of half-lantern cyclometalated Pt(II)‒Pt(II) complexes were was evaluated using MTT, apoptosis, cell cycle analysis, and DNA binding studies.

MATERIALS AND METHODS

The cytotoxicity of Pt(II)‒Pt(II) complexes were evaluated against different cancer cell lines such as human lung (A549), breast (MCF-7, and MDA-MB-231), ovarian (SKOV-3), and colon (HT-29) as well as normal breast (MCF-10A), and human lung fibroblast MRC-5 cells using MTT assay. BioLegend's PE Annexin V Apoptosis Detection Kit with 7AAD was applied to assess the apoptotic effects of 1A, and 1B compound against MCF-7, and A549 cell lines. Cell cycle analysis was determined using the flowcytometry method. The interaction of compounds with four different DNA structures with PDB codes (1BNA, 1LU5, 3CO3, and 198D) has been investigated by molecular docking. To achieve binding to DNA experimentally, the electrophoresis mobility shift assay and comet assay was applied.

RESULTS

In the evaluation of cytotoxic effects, 1A showed the highest cytotoxicity among the studied compounds, and it showed higher potency with more selectivity against normal cell lines than cisplatin. This compound had IC50 of 7.24, 2.21, 1.18, 2.71, 10.65, 18.32 and 49.21 μM against A549, SKOV3, HT29, MCF-7, MDA-MB-231, MRC-5, and MCF-10A, respectively, whereas cisplatin had IC50 of 9.75, 19.02, 107.23, 15.20, 18.09, 14.36, and 24.21 μm, respectively, on the same cell lines. In order to check the DNA binding activity of 1A, and 1B, electrophoretic mobility was also conducted, which indicated that the binding of these compounds led to a slight change in electrophoretic mobility to DNA. The migration of chromosomal DNA from the nucleus in the form of a tail or comet was executed in the comet assay of 1A on MCF-7. Examination of apoptosis of 1A, and 1B on the MCF-7 cancer cell line, showed that it could increase induction of apoptosis in this cancerous cell in a concentration-dependent manner. Investigating the effect of 1A using cell cycle analysis on MCF-7 cancer cell line showed that this complex affects the stage G1 and S of the cell cycle.

CONCLUSION

1A has the potential to play a significant role in future biopharmaceutical studies.

The status of isocyanide-based multi-component reactions in Iran (2010-2018)

Isocyanides as key intermediates and magic reactants have been widely applied in organic reactions for direct access to a broad spectrum of remarkable organic compounds. Although the history of these magical compounds dates back more than 100 years, it still has been drawing widespread attention of chemists who confirmed their versatility and effectiveness. Because of their wide spectrum of pharmacological, industrial and synthetic applications, many reactions with the utilization of isocyanides are reported in the literature. In this context, Iranian scientist played a significant role in the growth of isocyanides chemistry. The present review article covers literature from the period starting from 2010 onward and encompasses new synthetic routes and organic transformation involving isocyanides by Iranian researchers. During this period, a diverse range of isocyanide-based multi-component reactions (I-MCRs) has been reported such as a new modification of Ugi, post-Ugi, Passerini and Groebke-Blackburn-Bienayme condensation reactions, isocyanide-based [1 + 4] cycloaddition reactions, isocyanide-acetylene-based MCRs, isocyanide and Meldrum's acid-based MCRs, several unexpected reactions besides green mediums and novel catalytic systems for the synthesis of diverse kinds of pharmaceutically and industrially remarkable heterocyclic and linear organic compounds. This review also emphasizes the neoteric applications of I-MCR for the synthesis of valuable peptide and pseudopeptide scaffolds, enzyme immobilization and functionalization of materials with tailorable properties that can play important roles in the plethora of applications.

trans-Platinum(II) Thionate Complexes: Synthesis, Structural Characterization, and in vitro Biological Assessment as Potent Anticancer Agents

A series of Pt(II) complexes trans-[Pt(PPh2 allyl)2 (κ1 -S-SR)2 ], 1, PPh2 allyl=allyldiphenylphosphine, SR=pyridine-2-thiol (Spy, 1 a), 5-(trifluoromethyl)-pyridine-2-thiol (SpyCF3 -5, 1 b), pyrimidine-2-thiol (SpyN, 1 c), benzothiazole-2-thiol (Sbt, 1 d), benzimidazole-2-thiol (Sbi, 1 e), were synthesized. They were characterized by NMR, HR ESI-MS, and X-ray crystallography. Treatment of human cancer cell lines (A549, SKOV3, MCF-7) with these complexes resulted in promising antitumor effects in comparison with cisplatin. These compounds showed suitable selectivity between tumorigenic and non-tumorigenic (MCF-10 A) cell lines. Analyses of cell cycle progression and apoptosis were conducted for 1 a, the most cytotoxic compound, to screen dose/time response and to study the antiproliferative mechanism. An electrophoresis mobility shift assay was performed to assess the direct interaction of 1 a with DNA and the strong genotoxic ability was indicated through the comet assay method.