Preparation and cell growth inhibitory activity of [PtR(2)L(2)] (R=polyfluorophenyl, L(2)=diene, cyclohexane-1,2-diamine (chxn) or cis-(dimethyl sulfoxide)(2)) and the X-ray crystal structure of [Pt(C(6)F(5))(2)(cis-chxn)]

Dynamics of the efficient cyclometalation of the undercoordinated organoplatinum complex [Pt(COD)(neoPh)]+ (neoPh = 2-methyl-2-phenylpropyl)

The cyclometalation reaction of [Pt(COD)(κ¹-neoPh)]⁺ (neoPh = 2-methyl-2-phenylpropyl) to [Pt(COD)(κ²-neoPh)] was studied experimentally and mechanistically using DFT and MD simulations.

Synthesis and anti-proliferative activities of amine capped Pd and Pt macrocycles of 4,4′-dipyridylselenides

Symmetric macrocyclic complexes characterized as dimeric and their oligomeric form in water and the solid state exhibit high in vitro anticancer activities.

Pentafluorophenyl Platinum(II) Complexes of PTA and its N-Allyl and N-Benzyl Derivatives: Synthesis, Characterization and Biological Activity

From the well-known 1,3,5-triaza-phosphaadamantane (PTA, 1a), the novel N-allyl and N-benzyl tetrafuoroborate salts 1-allyl-1-azonia-3,5-diaza-7-phosphaadamantane (APTA(BF₄), 1b) and 1-benzyl-1-azonia-3,5-diaza-7-phosphaadamantane (BzPTA(BF₄), 1c) were obtained. These phosphines were then allowed to react with (Pt(μ-Cl)(C₆F₅)(tht))₂ (tht = tetrahydrothiophene) affording the water soluble Pt(II) complexes trans-(PtCl(C₆F₅)(PTA)₂) (2a) and its bis-cationic congeners trans-(PtCl(C₆F₅)(APTA)₂)(BF₄)₂ (2b) and trans-(PtCl(C₆F₅)(BzPTA)₂)(BF₄)₂ (2c). The compounds were fully characterized by multinuclear NMR, ESI-MS, elemental analysis and (for 2a) also by single crystal X-ray diffraction, which proved the trans configuration of the phosphine ligands. Furthermore, in order to evaluate the cytotoxic activities of all complexes the normal human dermal fibroblast (NHDF) cell culture were used. The antineoplastic activity of the investigated compounds was checked against the human lung carcinoma (A549), epithelioid cervix carcinoma (HeLa) and breast adenocarcinoma (MCF-7) cell cultures. Interactions between the complexes and human serum albumin (HSA) using fluorescence spectroscopy and circular dichroism spectroscopy (CD) were also investigated.

Doltsinis N, Klein A. Reactions of the organoplatinum complex [Pt(cod) (neoSi)Cl] (neoSi = trimethylsilylmethyl) with the non-coordinating anions SbF6– and BPh4–

Reactions of the organoplatinum complex [Pt(cod)(neoSi)Cl] (neoSi = (trimethylsilylmethyl) with the Ag(I) salts of oxo or fluoride containing anions A– = NO3–, ClO4–, OTf – (trifluoromethanesulfonate) and SbF6– lead to the desired abstraction of the chlorido ligand and precipitation of AgCl. However, further reaction of the resulting Pt complexes [Pt(cod)(neoSi) (solvent)]+ with diverse N-heterocyclic ligands L such as pyridines, caffeine, and guanine did not yield the targeted complexes [Pt(cod)(neoSi)(L)](A) in most of the cases, but to extensive decomposition yielding [Pt(cod)(Me) (solvent)]+, thus transforming the neoSi into a methyl ligand. A detailed study on the reaction with SbF6– combining DFT calculations with NMR and MS revealed that Pt catalysed decomposition of SbF6‒ and fluorination of the neoSi silicon atom leading to FSiMe3. When reacting the parent complex with Ag(BPh4), the arylated derivative [Pt(cod)(neoSi)(Ph)] was obtained and characterised by multinuclear NMR, MS and single crystal XRD.

Synthesis and antiproliferative activity of a series of new platinum and palladium diphosphane complexes

New organometallic complexes [M(dppe)(R)₂] {where M = Pt or Pd, dppe = 1,2-bis(diphenylphosphano)ethane, and R = C₆F₄H-x (x = 6,5,4), C₆F₃H₂-3,5, C₆F₃H₂-5,6, C₆F₃H₂-3,6, C₆F₄(OMe)-4, and C₆F₄(cyclo-C₅H₁₀N)-4, the numbers x refer to the positions of the protons in the polyfluoroaryl ligands} were synthesised either through transmetalation from the dichlorido complexes [M(dppe)Cl₂] or through ligand exchange using [M(diene)Cl₂] precursor complexes with diene = 1,5-cyclooctadiene (cod) or 1,5-hexadiene (hex). Alternatively, [M(dppX)Cl(R)] complexes with dppX = dppm (1,1-bis(diphenylphosphano)methane), dppe, dppp (1,3-bis(diphenylphosphano)propane), and dppb (1,4-bis(diphenylphosphano)butane) were prepared in decarboxylation reactions from thallium(i) carboxylates Tl(O₂CR). The different preparative methods were compared in terms of yield and purity. Structural and spectroscopic data are reported for the new dppX- and diene-M(R)₂ complexes. Antiproliferative activity was investigated for these new complexes against the HT-29 (colon carcinoma) and MCF-7 (breast adenocarcinoma) cell lines, and the active compounds of this first series together with organometallic dppX or hex Pt^II or Pd^II complexes were then included in cell tests using L1210 (leukaemia cells) and the cisplatin-resistant L1210/DDP cell line. Remarkably, promising antiproliferative results were found for a few Pt^II and Pd^II complexes, while structurally closely related compounds were essentially nontoxic.

Synthesis, structural characterization, biological evaluation and molecular docking studies of new platinum(ii) complexes containing isocyanides

Platinum(ii) complexes with various isocyanides are prepared and their biological activities are studied.

α-Diimine homologues of cisplatin: synthesis, speciation in DMSO/water and cytotoxicity

α-Diimine Pt(ii) complexes display variable stability in DMSO and DMSO/water mixtures, depending on the nature of the N-substituents. The most stable compounds are moderately cytotoxic, or are essentially inactive, against A2780 and A2780cisR cancer cell lines.

9,9-Difluorobispidine Analogues of Cisplatin, Carboplatin, and Oxaliplatin

As part of a comprehensive study of N-unsubstituted bispidines, the novel 9,9-difluorobispidine (D) has been synthesized. The compound crystallizes from pentane below 0 °C in the ordered-crystalline phase D-II and undergoes at 0-30 °C a stepwise endothermic phase transition to a dynamically disordered crystalline phase D-I; melting occurs at 227 °C. Single crystalline D-II has been subjected to X-ray structure analysis, revealing association of the molecules to form chains. Reaction of (1,5-hexadiene)PtCl₂ with D affords {C₇H₁₀F₂(NH)₂}PtCl₂ (D1), which can be converted by conventional routes to {C₇H₁₀F₂(NH)₂}Pt(cbdca)·5H₂O (D2) and {C₇H₁₀F₂(NH)₂}Pt(C₂O₄) (D3). Compound D1 crystallizes solvent-free from water and is isomorphous to the solvent-free parent bispidine analogue (A1). The pentahydrate D2 is isomorphous to the bispidine and 9-oxabispidine homologues (A2 and C2), as shown by X-ray structure analyses. An increased polarity of the bispidine skeleton as a consequence of the high electronegativity of fluorine is seen as the reason for low cytotoxic potency of D1-D3.

Cytotoxic properties of a new organometallic platinum(ii) complex and its gold(i) heterobimetallic derivatives

The high antiproliferative effects of a new organoplatinum(ii) complex are further enhanced upon coordination of a gold(i) phosphane moiety.

Cyclometalated Iminophosphorane Gold(III) and Platinum(II) Complexes. A Highly Permeable Cationic Platinum(II) Compound with Promising Anticancer Properties

New organometallic gold(III) and platinum(II) complexes containing iminophosphorane ligands are described. Most of them are more cytotoxic to a number of human cancer cell lines than cisplatin. Cationic Pt(II) derivatives 4 and 5, which differ only in the anion, Hg₂Cl₆^2– or PF₆^– respectively, display almost identical IC₅₀ values in the sub-micromolar range (25–335-fold more active than cisplatin on these cell lines). The gold compounds induced mainly caspase-independent cell death, as previously reported for related cycloaurated compounds containing IM ligands. Cycloplatinated compounds 3, 4, and 5 can also activate alternative caspase-independent mechanisms of death. However, at short incubation times cell death seems to be mainly caspase dependent, suggesting that the main mechanism of cell death for these compounds is apoptosis. Mercury-free compound 5 does not interact with plasmid (pBR322) DNA or with calf thymus DNA. Permeability studies of 5 by two different assays, in vitro Caco-2 monolayers and a rat perfusion model, have revealed a high permeability profile for this compound (comparable to that of metoprolol or caffeine) and an estimated oral fraction absorbed of 100%, which potentially makes it a good candidate for oral administration.

Structural and anticancer properties of hydrogen bonded diphenyl phosphate adducts of Pt(IV) complexes: the importance of pKa matching

Co-crystallisation of diphenyl phosphate (Hdpp) with anticancer active Pt(IV) complexes of the type cis,trans,cis-[PtCl(2)(OH)(2)(am(m)ine)(2)] has produced a new type of supramolecular adduct with short hydrogen bonds from the Hdpp molecules to the hydroxide ligands in all cases. X-ray crystallographic analysis showed within the adduct cis,trans-[PtCl(2)(en)(OH(2))(2)](dpp)(2) (1) a hydrogen bond length of 2.341(6) Å; the shortest O ··· O distance reported in the literature. Similar, though longer hydrogen bonds were observed in three other complexes: [PtCl(2)(OH)(NH(3))(2)(OH(2))]dpp·3H(2)O (2), trans-[Pt(mal)(OH)(OH(2))(S,S-chxn)]dpp·3H(2)O (3), and trans-[Pt(ox)(OH)(OH(2))(S,S-chxn)]dpp·2H(2)O (4). Co-crystallisation with Hdpp leads to higher aqueous solubility than the parent complexes indicating the potential of the adducts for use as active pharmaceutical ingredients. Anticancer testing of [Pt(mal)(OH)(OH(2))(S,S-chxn)]dpp·3H(2)O (3) showed in vitro cytotoxicity is low, as expected for Pt(IV) prodrugs, yet substantial tumour growth inhibition was observed in an in vivo ADJ/PC6 tumour model, with activity retained at maximum tolerated dose (MTD)/2 and MTD/4.