title: Novel imino thioether complexes of platinum(II): synthesis, structural investigation, and biological activity.
abstract: The reactions of the nitrile complexes cis- and trans-[PtCl2(NCR)2] (R = Me, Et, CH2Ph, Ph) with an excess of ethanethiol, EtSH, in the presence of a catalytic amount of n-BuLi in tetrahydrofuran (THF), afforded in good yield the bis-imino thioether derivatives cis-[PtCl2{E-N(H)═C(SEt)R}2] (R = Me (1), Et (2), CH2Ph (3), Ph (4)) and trans-[PtCl2{E-N(H)═C(SEt)R}2] (R = Me (5), Et (6), CH2Ph (7), Ph (8)). The imino thioether ligands assumed the E configuration corresponding to a cis addition of the thiol to the nitrile triple bond. The spectroscopic properties of these complexes have been reported along with the molecular structures of 1, 2, and 7 as established by X-ray crystallography which indicated that these compounds exhibit square-planar coordination geometry around the platinum center. Four N-H···Cl intermolecular contacts (N-H···Cl ca. 2.5-2.7 Å) between each chlorine atom and the N-H proton of the imino thioether ligand gave rise to "dimers" Pt2Cl4L4 (L = imino thioether) formed by two PtCl2L2 units. The cytotoxic properties of these new platinum(II) complexes were evaluated against various human cancer cell lines. Among all derivatives, trans-[PtCl2{E-N(H)═C(SEt)CH2Ph}2] showed the greatest in vitro cytotoxic activity being able to decrease cancer cell viability roughly 3-fold more effectively than cisplatin.
authors: Department of Industrial Engineering, University of Padua, Via F. Marzolo, 9, 35131 Padua, Italy.
authors: Paolo
authors: P
authors: Sgarbossa
authors: Silvia Mazzega
authors: SM
authors: Sbovata
authors: Roberta
authors: R
authors: Bertani
authors: Mirto
authors: M
authors: Mozzon
authors: Franco
authors: F
authors: Benetollo
authors: Cristina
authors: C
authors: Marzano
authors: Valentina
authors: V
authors: Gandin
authors: Rino A
authors: RA
authors: Michelin
mesh_terms: D000970:Antineoplastic Agents / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology*; D018360:Crystallography, X-Ray; D004305:Dose-Response Relationship, Drug; D004354:Drug Screening Assays, Antitumor; D006801:Humans; D007097:Imines / Q000737:chemistry*; D061986:MCF-7 Cells; D008958:Models, Molecular; D015394:Molecular Structure; D009944:Organoplatinum Compounds / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology*; D013329:Structure-Activity Relationship; D013440:Sulfides / Q000737:chemistry*; D014407:Tumor Cells, Cultured
chemical_list: D000970:Antineoplastic Agents; D007097:Imines; D009944:Organoplatinum Compounds; D013440:Sulfides