Papers by Valeria Ferretti
Journal of The Chemical Society-dalton Transactions, 1998
ABSTRACT
Tetrahedron, 1989
Forskolin (I) , a novel labdane diterpenoid isolated f r o m Coleus forskohlii, possesses, in add... more Forskolin (I) , a novel labdane diterpenoid isolated f r o m Coleus forskohlii, possesses, in addition t o eight chiral centers, a novel tetrahydropyran-4-one moiety fused to a highly oxygenated trans-decalin system. This paper reports our progress towards t h e synthesis of AB ring syst e x forskolin.
Inorganica Chimica Acta, 2017
A new one-pot synthetic procedure to new water-soluble rhenium and technetium complexes, directly... more A new one-pot synthetic procedure to new water-soluble rhenium and technetium complexes, directly from the corresponding permetallated species, is here presented. The new water-soluble M(IV) and M(III), (M = Re, Tc) paramagnetic complexes were obtained by treating [MO4]with an excess of PTA (1,3,5-triaza-7-phosphaadamantane), in water. In the presence of SnCl2, the complexes [MCl3(PTA)3]Cl, (M = Re, 1; Tc, 3), were obtained in good yield, while in the absence of SnCl2 the unexpected species containing methylated PTA, [MCl4(PTA-Me)2]Cl, (M = Re, 2; Tc, 4), were produced. A preliminary study of the reactivity of these products with N,N-diethyldithiocarbamate was also carried out: the diamagnetic binuclear μ-oxo species [M2O3(Et2NCS2)4] (M = Re, 6; Tc, 7) were isolated from the reactions of 1, 2 and 4 with dithiocarbamate. The reaction of 3 gave rise to an unusual epta-coordinated technetium(III) complex [Tc(Et2NCS2)3(PTA)] (5). The X-ray crystal structures of the new PTA complexes 2, 4, 5 and 7 have been determined.
Inorganica Chimica Acta, 2017
In honour of Carlo Mealli on the occasion of his 70th birthday ABSTRACT A group of new Pt(II) com... more In honour of Carlo Mealli on the occasion of his 70th birthday ABSTRACT A group of new Pt(II) complexes with dichloroacetate (DCA), bearing DMSO (cis-[Pt(DCA)2(Me2SO-S)2], 2) or phosphines (cis-[Pt(DCA)2(PPh3)(Me2SO-S)], 3, cis-[Pt(DCA)2(P)2], P = PPh3 3a, P = PTA 4a and [Pt(DCA)(P)3]DCA, P = PPh3 3b, P = PTA, 4b) as neutral ligands was prepared by a simple fast route from the inorganic synthon [PtCO3(Me2SO-S)2], 1. The x-ray crystal structures of 2, 3, 3a and 4a were determined. The antiproliferative activity of 2, 4a, and 4b was evaluated against two human cancer cell lines, cisplatin sensitive A2780 and cisplatin resistant SKOV-3, and the results were compared with known amine analogues and with the dichloride precursors.
Encyclopedia of Supramolecular Chemistry, 2004
From the analysis of CSD structural data, some chemical prerequisites can be identified as necess... more From the analysis of CSD structural data, some chemical prerequisites can be identified as necessary for the formation of cyclamers, at least in the solid state: molecules forming cyclamers are always characterized by the presence of both H-bond donor and acceptor groups. Because the cyclamer formation usually competes with the formation of other more common structural motifs, such as dimers or infinite chains, appropriate substitutions (for instance, bulky substituents) can sometimes prevent the formation of chains, making cyclic aggregations more probable. Moreover, cavities with large dimension, up to 10-15 A ° , can be observed provided that they are filled by substituent groups or small guest molecules. The identification of the complementary functional groups able to self-assemble to make up discrete homomolecular or host-guest systems leads to the design of new supramolecular structures for fruitful applications in chemistry, material chemistry, crystal engineering, and biological chemistry. Because many cyclamers exist also in solution, understanding how some molecules self-assemble by mutual recognition using noncovalent bonds could be crucial to ‘‘emulate natural systems, for example, in the development of synthetic enzymes, efficient gene therapy, or drug delivering systems
Dalton Transactions, 2016
A new simple, eco-friendly route to anticancer Pt(ii)–carboxylate complexes is described, based o... more A new simple, eco-friendly route to anticancer Pt(ii)–carboxylate complexes is described, based on the new water-soluble synthon [PtCO3(Me2SO-S)2] (1), whose ligands can be easily replaced by O-donors.
ChemInform, 1989
The tricyclic model compound (XI), which possesses seven of the eight stereocenters of forskolin,... more The tricyclic model compound (XI), which possesses seven of the eight stereocenters of forskolin, is prepared starting from α‐damascone (I).
New Journal of Chemistry, 2017
Reaction of hydrated copper(II) ibuprofenate with various nitrogen donor ligands, β-picoline, γpi... more Reaction of hydrated copper(II) ibuprofenate with various nitrogen donor ligands, β-picoline, γpicoline, pyrrolidine and unsymmetrical ethylenediamine (un-dmen), at room temperature in methanol:water mixture (4:1 v/v) yielded four new complexes, [Cu(Ibu)2(-picoline)2(H2O)]; 1, [Cu(Ibu)2(-picoline)2(H2O)].H2O; 2, [Cu(Ibu)2(pyrrolidine)2].H2O; 3 and [Cu(undmen)2(H2O)](Ibu)2; 4 respectively, where Ibu = deprotonated Ibuprofen (HIbu). The newly synthesized complexes have been characterized by elemental analyses, spectroscopic methods (FT-IR, UV-Vis and EPR), TGA and single crystal X-ray structure determination. Crystallographic investigations revealed that all the complexes are monomeric in nature, in contrast to dimeric nature of copper(II) ibuprofenate solvates. EPR studies clearly revealed that the chromophore present in all complexes (1-4) is consistent with structures determined by X-ray crystallography. The cytotoxic effects of all complexes were tested by a colorimetric assay on three human cell lines; though the activity resulted to be affected by the nature of the cell line, the newly synthesized complexes 1-4 showed higher cytotoxicity than parent molecule against all the tumoral cell lines.
Combining a pharmaceutical active ingredient (API) with a pharmaceutically acceptable agent, to o... more Combining a pharmaceutical active ingredient (API) with a pharmaceutically acceptable agent, to obtain the so-called ‘pharmaceutical co-crystal’, has become an increasingly attractive route for developing new products with enhanced physico-chemical properties. Since the co-crystal coformers are assembled through intermolecular interactions which are different from those found in the crystals of the pure components, these new solid forms can exhibit improved solubility, dissolution rate, bioavailability, permeability and stabiity properties retaining at the same time the unaltered chemical structure of the APIs. Very recently, however, we have shown for the first time [1,2] that a drug dissolved from its co-crystals or from a API/coformer physical mixture can have greatly different effects both on the integrity of cell monolayers and on API permeability. Our analysis has brought to light an intriguing aspect of the biological properties of pharmaceutical co-crystals which can be drastically different from those of their parent physical mixtures. As a further development of this type of investigation, the present communication deals with the evaluation of the dissolution properties and permeation ability across human intestinal cell monolayers of (i) carbamazepine (CBZ), a poorly water soluble anti-epileptic drug,; (ii) two new CBZ co-crystals with vanillic acid and 4-nitropyridine-N-oxyde and (iii) a published CBZ co-crystal with succinic acid. Overall, the results confirm our previous findings. The crystal structure of the CBZ-vanillic acid and the dissolution profiles of the physical mixtures considered in this work are reported in Fig. 1 Moreover, in order to elucidate at a molecular level the dissolution processes in water, we have implemented our investigation with DFT and molecular dynamics studies
Journal of Inorganic Biochemistry, Oct 1, 2019
We herein describe the synthesis and characterization of the new amido-phosphinic ligand 3,7‑bis(... more We herein describe the synthesis and characterization of the new amido-phosphinic ligand 3,7‑bis(dichloroacetyl)‑1,3,7‑triaza‑5‑phosphabicyclo[3.3.1]nonane (DCP), a derivative of dichloroacetic acid (DCA), whose ability to reverse the suppressed mitochondrial apoptosis in cancer cells is known. DCP was obtained by a double N-acylation of PTA (1,3,5‑triaza‑7‑phosphaadamantane) occurring with loss of CH2, in appropriate conditions. Due to the hindered rotation around the amidic CN bonds, three rotameric forms of DCP were observed, whose ratio in solution was dependent on the solvent, while the X-ray crystal structure of DCP showed an opposite orientation of the two amidic carbonyl groups (anti rotamer). The lipophilic, air and thermally stable DCP was found able to act regiospecifically as a P-donor ligand toward soft metal ions. By ligand substitution on appropriate precursors, we obtained the complexes 1-9, where proapoptotic DCA is associated with metal ions of known cytotoxic activity on cancer cells (Pt2+, Pd2+, Ru2+, Re+, Au+). The antiproliferative activity of DCP and its complexes was tested in vitro, in comparison with cisplatin, on three human tumor cell lines: A2780 (ovarian cisplatin-sensitive), A2780cis (ovarian cisplatin-resistant) and K562 (erythroleukemic). The results showed that the simultaneous presence of DCP (containing two residues of proapoptotic DCA) and Pt(II) produces the best performances with respect to non-platinum complexes. Experiments of pro-apoptotic activity indicated that the antiproliferative activity of the most active DCP-Pt(II) complexes is associated with induction of apoptosis.
ChemInform, Oct 25, 1988
The square‐pyramidal nitrido‐Tc(V) complexes (I), (II), and (III) are synthesized by substitution... more The square‐pyramidal nitrido‐Tc(V) complexes (I), (II), and (III) are synthesized by substitution‐reduction reactions of (NBu4) (TcNCl4) or (AsPh4) (TcNCl4) with the corresponding tri‐ and bidentate Schiff bases and/or without PPh3 or by substitution reactions of TcNCl2(PPh3)2.
Inorganica Chimica Acta, Jul 1, 1991
... Full Text via CrossRef | View Record in Scopus | Cited By in Scopus (57). 27. KW Penfield, RR... more ... Full Text via CrossRef | View Record in Scopus | Cited By in Scopus (57). 27. KW Penfield, RR Gay, RS Himmelwright, NC Eickman, VA Norris, HC Freeman and EI Solomon. J. Am. ... 46. PADuckworth, FS Stephens, KP Wainwright, KDV Weerasuria and SB Wild. Inorg. Chem. ...
Chemischer Informationsdienst, Aug 26, 1986
ChemInform Abstract (deviation from planarity for 90 molecules containing the title group (e.g. X... more ChemInform Abstract (deviation from planarity for 90 molecules containing the title group (e.g. X: = O, = S, = NMe, = CMez; R'-R3:-Me) in the cryslal environ. ment: proposal of an energetic model based on molecular mechanics calculations.
ChemInform, Nov 14, 1989
ChemInform Abstract The mode of binding of DMSO in chloro(diamine)-Pt(II) and-Pd(II) cations (dia... more ChemInform Abstract The mode of binding of DMSO in chloro(diamine)-Pt(II) and-Pd(II) cations (diamine: 2,2'-bipyridine, 1,10-phenanthroline, or en) is examined. IR spectra of the complexes in solid state indicate that DMSO binds through the O atom in the Pd(II) complexes (I) and through the S atom in the complexes (II). 1H NMR spectra in CD3NO3 solution show that the complexes (II) retain their structure in solution, while the complexes (I) equilibrate to a mixture of Sand O-bonded isomers. The structures of the square planar title compounds (I) (N-N: bipyridyl, X: BF4; space group P1, Z=2) and (IIa) (X: ClO4; P21/n, Z=4) are confirmed by X-ray analysis. The complexes studied are prepared from corresponding dichloro(diamine)-metal(II) complexes and AgX in DMSO with about 80% yield.
Uploads
Papers by Valeria Ferretti