Grazia Papini
University of Camerino
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Publication
Featured researches published by Grazia Papini.
Journal of Medicinal Chemistry | 2008
Cristina Marzano; Valentina Gandin; Maura Pellei; Davide Colavito; Grazia Papini; Giancarlo Gioia Lobbia; Elda Del Giudice; Marina Porchia; Francesco Tisato; Carlo Santini
Monocationic hydrophilic complexes [Cu(thp)4](+) 3 and [Cu(bhpe)2](+) 4 were synthesized by ligand exchange reactions starting from the labile [Cu(CH3CN)4][PF6] precursor in the presence of an excess of the relevant hydrophilic phosphine. Complexes 3 and 4 were tested against a panel of several human tumor cell lines. Complex 3 has been shown to be about 1 order of magnitude more cytotoxic than cisplatin. Chemosensitivity tests performed on cisplatin and multidrug resistance phenotypes suggested that complex 3 acts via a different mechanism of action than the reference drug. Different short-term proliferation assays suggested that lysosomal damage is an early cellular event associated with complex 3 cytotoxicity, probably mediated by an increased production of reactive oxygen species. Cytological stains and flow cytometric analyses indicated that the phosphine copper(I) complex is able to inhibit the growth of tumor cells via G2/M cell cycle arrest and paraptosis accompanied with the loss of mitochondrial transmembrane potential.
Journal of Inorganic Biochemistry | 2011
Carlo Santini; Maura Pellei; Grazia Papini; Barbara Morresi; Rossana Galassi; Simone Ricci; Francesco Tisato; Marina Porchia; Maria Pia Rigobello; Valentina Gandin; Cristina Marzano
Hydrophilic, monocationic [M(L)(4)]PF(6) complexes (M = Cu or Ag; L: thp = tris(hydroxymethyl)phosphine, L: PTA = 1,3,5-triaza-7-phosphaadamantane, L: thpp = tris(hydroxypropyl)phosphine) were synthesized by ligand exchange reaction starting from [Cu(CH(3)CN)(4)]PF(6) or AgPF(6) precursors at room temperature in the presence of an excess of the relevant phosphine. The related [Au(L)(4)]PF(6) complexes (L = thp, PTA or thpp) were synthesized by metathesis reactions starting from [Au(L)(4)]Cl at room temperature in the presence of equimolar quantity of TlPF(6). The three series of complexes [M(L)(4)]PF(6) were tested as cytotoxic agents against a panel of several human tumour cell lines also including a defined cisplatin resistant cell line. These investigations have been carried out in comparison with the clinically used metallodrug cisplatin and preliminary structure-activity relationships are presented. The best results in terms of in vitro antitumour activity were achieved with metal-thp species and, among the coinage metal complexes, copper derivatives were found to be the most efficient drugs. Preliminary studies concerning the mechanism of action of these [M(L)(4)]PF(6) species pointed to thioredoxin reductase as one of the putative cellular targets of gold and silver complexes and provided evidence that copper derivatives mediated their cytotoxic effect through proteasome inhibition.
Dalton Transactions | 2009
Grazia Papini; Maura Pellei; Giancarlo Gioia Lobbia; Alfredo Burini; Carlo Santini
New N-heterocyclic carbene ligand precursors {H(2)C(HTz(R))(2)} and {H(2)C(HIm(R))(2)} (HTz = 1,2,4-triazole; HIm = imidazole; R = PrSO(3) or EtCOO) were obtained starting from the compounds bis(1,2,4-triazol-1-yl)methane and bis(imidazol-1-yl)methane. The related silver(i) carbene complexes were prepared in degassed water solution by treatment of the triazolium or imidazolium species with Ag(2)O, resulting in well-characterized and water soluble bimetallic complexes of general formula {Na(2)[H(2)C(Tz(R))(2)](2)Ag(2)} and {Na(2)[H(2)C(Im(R))(2)](2)Ag(2)}. In these metallacycles every silver atom is coordinated to two triazolin- or imidazolin-2-ylidene rings, belonging to two different dicarbene units.
Rapid Communications in Mass Spectrometry | 2010
Francesco Tisato; Fiorenzo Refosco; Marina Porchia; Matteo Tegoni; Valentina Gandin; Cristina Marzano; Maura Pellei; Grazia Papini; Lara Lucato; Roberta Seraglia; Pietro Traldi
Electrospray ionization mass spectrometry was usefully employed for the characterization of three phosphino copper(I) complexes of medicinal interest. This technique revealed that the original [CuL(4)](+) pro-drugs (L = hydrophilic tertiary phosphine) underwent dissociation with production of coordinative unsaturated [CuL(3)](+) and [CuL(2)](+) species, which represented key intermediates for the activation of potential biological properties. The more favoured was the displacement of the ligands from the [CuL(4)](+) parent complex, the more favoured was in turn the possibility for the metal ion to directly interact with biological substrates, including pharmacological targets related to cancer proliferation. An inverse correlation between the stability and the cytotoxic activity of the three copper(I) complexes investigated has been clearly established.
Current Bioactive Compounds | 2009
Maura Pellei; Grazia Papini; Giancarlo Gioia Lobbia; Carlo Santini
The structural and functional properties of group 6 metal complexes with scorpionate ligands, used as synthetic analogues for the binding sites of the molybdenum and tungsten enzymes, are the subject of the present review. The group 6 elements molybdenum and tungsten are the only second and third row transition metals essential to all forms of life on Earth. Molybdenum is found at the active sites of nitrogenase and all of the more than 50 known Mo-molybdopterin (Mo- MPT) enzymes that play vital roles in plant, animal, and human health, the carbon, sulfur, and nitrogen cycles, biofeedback systems, and the control of global climate; tungsten is also associated with MPTbased ligands in all its known biological manifestations. Chemical approaches to molybdenum enzyme sites have been directed toward mimicking a portion of the structural center in order to ascertain the role of that particular feature of the center on the chemical reactivity and the spectroscopic properties of the center. Here we attempt to analyze the overall progress on synthetic analogues of these enzyme centers and dissect the contributions of systems in which coordination spheres contain poly(pyrazolyl)borate ligands, focusing primarily on research that has appeared since the structures of the active sites of representative enzymes have become known.
Dalton Transactions | 2009
Grazia Papini; Simone Alidori; Jason S. Lewis; David E. Reichert; Maura Pellei; Giancarlo Gioia Lobbia; Gráinne B. Biddlecombe; Carolyn J. Anderson; Carlo Santini
The aim of this work was to prepare a novel class of (64)Cu(II) labeled complexes with the new macrocyclic ligands 1,10-dithia-4,7-diazacyclododecane-3,8-dicarboxylic acid (NEC-SE, 1), 1,10-dithia-4,7-diazacyclotridecane-3,8-dicarboxylic acid (NEC-SP, 2) and 1,10-dithia-4,7-diazacyclotetradecane-3,8-dicarboxylic acid, (NEC-SB, 3 ) to evaluate the usefulness of these macrocycles for potential utility as (64)Cu(II) chelators. The corresponding non-radioactive complexes [Cu(NEC-SE)] x 3H(2)O (4), [Cu(NEC-SP)] x 3H(2)O (5) and [Cu(NEC-SB)] (6) were prepared and their (64)Cu-analogs, [(64)Cu(NEC-SE)] (7) and [(64)Cu(NEC-SP)] (8) and [(64)Cu(NEC-SB)] (9) were produced in >98% radiochemical purity. Rats were injected with complex 7, 8 or 9 and were euthanized at 1, 4 and 24 h. All three complexes are cleared from the blood over the first hour following injection but there is poor clearance of this activity over 24 h. A similar pattern of retention was noted in the liver where the levels of activity in this tissue at 1 h are not statistically different from those at 24 h. Molecular mechanics and DFT studies were performed on the complexes in order to gain insight into the lower stability.
Mini-reviews in Organic Chemistry | 2010
Carlo Santini; Maura Pellei; Giancarlo Gioia Lobbia; Grazia Papini
Journal of Biological Inorganic Chemistry | 2008
Simone Alidori; Giancarlo Gioia Lobbia; Grazia Papini; Maura Pellei; Marina Porchia; Fiorenzo Refosco; Francesco Tisato; Jason S. Lewis; Carlo Santini
Inorganic Chemistry | 2005
Marina Porchia; Grazia Papini; Carlo Santini; Giancarlo Gioia Lobbia; Maura Pellei; Francesco Tisato; Giuliano Bandoli; Alessandro Dolmella
Dalton Transactions | 2011
Giuliana Aquilanti; Marco Giorgetti; Marco Minicucci; Grazia Papini; Maura Pellei; Matteo Tegoni; Andrea Trasatti; Carlo Santini