Cyclometalated Platinum(II) Complexes Comprising 2‐(Diphenylphosphino)pyridine and Various Thiolate Ligands: Synthesis, Spectroscopic Characterization, and Biological Activity. Issue 15 (25th April 2017)

• Record Type: Journal Article
• Authors: Fereidoonnezhad, Masood; Niazi, Maryam; Ahmadipour, Zohreh; Mirzaee, Tabassom; Faghih, Zeinab; Faghih, Zahra; Shahsavari, Hamid R.
• Is Part Of: European journal of inorganic chemistry. Issue 15(2017)
• Page Start: 2247
• Page End: 2254
• Publication Date: 2017-04-25
• Subjects: Pyridine ligands -- Platinum -- Thiolate ligands -- Biological activity -- Molecular modeling; Chemistry, Inorganic -- Periodicals; Organometallic chemistry -- Periodicals; Bioinorganic chemistry -- Periodicals; Solid state chemistry -- Periodicals; 546
• DOI: 10.1002/ejic.201601521
• Languages: English
• ISSNs: 1434-1948

Abstract

Abstract : The known cyclometalated platinum(II) complex [Pt(ppy)(DMSO)(Cl)] (A ) in which ppy = 2‐phenylpyridinate, was treated with 2‐(diphenylphosphino)pyridine (PPh2 py, PN) (1 equiv.) and readily afforded complex [Pt(ppy)(PPh2 py‐κ1P)(Cl)] (1 ). The transphobia effect (T) and single‐crystal X‐ray diffraction crystallography confirmed that the phosphine ligand in1 is located trans to the nitrogen atom of the cyclometalating fragment (ppy). Compound1 was treated with various thiolate reagents (1 equiv.) at room temperature, leading to the displacement of the chloride ligand in1 by thiolate ligands through a salt metathesis reaction. The reaction led to the formation of a series of monomeric complexes with the general formula [Pt(ppy)(PPh2 py‐κ1P)(SR)] (2a –2d ), where SR = deprotonated form of pyridine‐2‐thiol (HSpy, 2a ), pyrimidine‐2‐thiol (HSpyN, 2b ), thiophenol (HSPh, 2c ), and 2‐thiazoline‐2‐thiol (HSt, 2d ). All complexes have been characterized by NMR spectroscopy. The biological activities of the complexes were evaluated against three human cancer cell lines, including A549 (human lung cancer), SKOV3 (human ovarian cancer), and MCF7 (human breast cancer), by means of the MTT assay [MTT = 3‐(4, 5‐dimethylthiazol‐yl)‐2, 5‐diphenyltetrazolium bromide]. Compounds2a and2b presented effective, potent cytotoxic activity regarding the cell lines. Electrophoretic mobility shift assays on plasmid DNA and molecular modeling investigations were also performed to determine the specific binding mode or the binding orientation of the complexes to DNA. Abstract : Platinum(II) complexes of the type [Pt(ppy)(PPh2 py‐κ 1 P )(SR)] (2 ), where PPh2 py is 2‐(diphenylphosphino)pyridine and HSR are four selected thiolate ligands, were prepared from the complex [Pt(ppy)(PPh2 py‐κ 1 P )(Cl)] (1 ). In vitro cytotoxic activities against a panel of three human cancer cell lines were evaluated, showing high inhibition of cellular growth, with an IC50 comparable to that of cisplatin.