1,720,968 research outputs found
Sintesi, caratterizzazione e attività biologica di complessi di Au(III) con leganti ditiocarbammici
No full textSynthesis, characterization and in vitro antitumoral activity of new Pt(II) and Pd(II) complexes with 2-/3-picoline and dithiocarbamate ligands
No full textGold(III) dithiocarbamate derivatives as potential antitumor agents: synthesis, characterization, solution chemistry and cytotoxic properties
No full textMixed complexes of Pt(II) and Pd(II) with ethylsarcosinedithiocarbamate and 2-/3-picoline as antitumor agents
No full textThe [M(ESDT)Cl](n) (M = Pt(II), Pd(II); ESDT = EtO(O)CCH2N(CH3)CS2-, ethylsarcosinedithiocarbamate ion) species have been reacted with 2- or 3-picoline in dichloromethane in order to obtain mixed ligand complexes of the type [M(ESDT)(L)Cl] (L = 2-picoline, 3-picoline). The synthesized compounds have been isolated, purified and characterized by means of elemental analyses, H-1-/C-13-/(HC)-H-1-C-13-HMBC (heteronuclear multiple bonding coherence) NMR and FT-IR spectroscopy. The biological activity of the compounds reported here has been then determined in terms of cell growth inhibition, DNA synthesis inhibition, detection of interstrand cross-links and DNA-protein cross-links, and micronuclei (MN) detection on a panel of tumor cell lines both sensitive and resistant to cisplatin. On the basis of the experimental results, coordination in the above mentioned complexes takes place in a near square-planar geometry, the dithiocarbamate moiety acting as a chelating agent, whereas the two remaining coordination sites are occupied by a chlorine atom and an amino ligand. Above all, [Pt(ESDT)(2-picoline)Cl] complex has shown very encouraging cytotoxicity levels higher or, at least, comparable to those exerted by cisplatin in the same experimental conditions
T4 Phage photoinactivation by linear furocoumarins and angular furoquinolinones
No full textTMP, FQ, and HFQ kill T4 phage under mild experimental conditions in its virion form, but not in its vegetative form. The process occurs through a two-step irradiation procedure, characteristic of DNA bifunctional lesions. We hypothesize the induction of DNA–protein cross-links in mature phages that can inhibit the infection process
Solution behaviour and biological activity of bisamidine complexes of platinum(II)
No full textA series of platinum(II) amidine complexes were previously prepared with the aim of obtaining a new class of platinum-based antitumour drugs. This series includes compounds of the type cis-[PtCl2{Z-HN=C(NHMe)Me}(2)] and trans-[PtCl2{Z-HN=C(NHMe)Me}(2)] (1, 2), cis-[PtCl2{E-HN=C(NMe2)Me}(2)] and trans-[PtCl2{E-HN=C(NMe2)Me}(2)] (3, 4), cis-[PtCl2{Z-HN=C(NHMe)Ph}(2)] and trans-[PtCl2{Z-HN=C(NHMe)Ph}(2)] (5, 6), and cis-[PtCl2{HN=C(NMe2)Ph}(2)] and trans-[PtCl2{HN=C(NMe2)Ph}(2)] (7, 8). The reactions with dimethyl sulfoxide were studied for complexes 5-8; the formation of cationic species containing coordinated dimethyl sulfoxide was demonstrated by NMR experiments and electrospray ionization mass spectrometry. In this work, the amidine platinum(II) complexes were tested for their in vitro cytotoxicity on a panel of various human cancer cell lines. The results indicate that the benzamidine complex 8 was the most effective derivative also circumventing acquired cisplatin resistance as demonstrated by chemosensitivity tests performed on cisplatin-sensitive and cisplatin-resistant cell lines. The studies concerning the cellular DNA damage on both parental chemosensitive and resistant sublines suggest for the new trans-amidine complex a different mechanism of action compared with that exhibited by cisplatin
Gold dithiocarbamate derivatives as potential antineoplastic agents: design, spectroscopic properties and in vitro antitumor activity
No full textAt present, cisplatin (cis-diamminodichloroplatinum(II)) is one of the most largely employed anticancer drugs as it is effective in the treatment of 70-90% of testicular and, in combination with other drugs, of ovarian, small cell lung, bladder, brain, and breast tumors. Anyway, despite its high effectiveness, it exhibits some clinical problems related to its use in the curative therapy, such as a severe normal tissue toxicity (in particular, nephrotoxicity) and the frequent occurrence of initial and acquired resistance to the treatment. To obtain compounds with superior chemotherapeutic index in terms of increased bioavailability, higher cytotoxicity, and lower side effects than cisplatin, we report here on some gold(I) and gold(III) complexes with dithiocarbamate ligands (DMDT = N,N-dimethyldithiocarbamate; DMDTM = S-methyl-N,N- dimethyldithiocarbamate; ESDT = ethylsarcosinedithiocarbamate), which have been synthesized, purified, and characterized by means of elemental analyses, conductivity measurements, mono- and bidimensional NMR, FT-IR, and UV-vis spectroscopy, and thermal analyses. Moreover, the electrochemical properties of the designed compounds have been studied through cyclic voltammetry. All the synthesized gold complexes have been tested for their in vitro cytotoxic activity. Remarkably, most of them, in particular gold(III) derivatives of N,N-dimethyldithiocarbamate and ethylsarcosinedithiocarbamate, have been proved to be much more cytotoxic in vitro than cisplatin, with IC50 values about 1- to 4-fold lower than that of the reference drug, even toward human tumor cell lines intrinsically resistant to cisplatin itself. Moreover, they appeared to be much more cytotoxic also on the cisplatin-resistant cell lines, with activity levels comparable to those on the corresponding cisplatin-sensitive cell lines, ruling out the occurrence of cross-resistance phenomena and supporting the hypothesis of a different antitumor activity mechanism of action
Characterization studies and cytotoxicity assays of Pt(II) and Pd(II) dithiocarbamate complexes by means of FT-IR, NMR spectroscopy and mass spectrometry
No full textThe precursors [M(ESDTM)Cl-2] (M = Pt(II), Pd(II); ESDTM EtO2CCH2(CH3)NCS2Me, S-methyl(ethylsarcosinedithiocarbamate)) were synthesized as previously reported [J. Inorg. Biochem. 83 (2001) 31] and used to obtain [M(ESDT)Cl],, (ESDT = ethylsarcosinedithiocarbamate anion) species. The complexes formed through reaction between [M(ESDT)Cl],, and the two chiral amino-alcohols synephryne (Syn) and norphenylephrine (Nor) have been synthesized, with the ultimate goal of preparing mixed dithiocarbamate/amino metal complexes of the type [M(ESDT)(Am)Cl] (Am = Syn, Nor). These compounds have been isolated, purified and characterized by means of FT-IR, mono- and bidimensional NMR spectroscopy and mass spectrometry ESI/ MS (electronspray mass spectra). The experimental data suggest that in all cases coordination of the dithiocarbamate ligand (ESDT) takes a place through the two sulfur atoms, the -NCSS moiety acting as a symmetrical bidentate chelating group, in a square-planar geometry around the M(11) ion, while the other two coordination positions are occupied by the chlorine atom and the amino-alcohol ligand, respectively. In particular, synephrine and norphenylephrine appear to be bound to the metal atom through the amino nitrogen atom by means of a dative bond.
Finally, the biological activity of the new complexes has been studied by MTT (tetrazolio salt reduction) test and by detecting the inhibition of DNA synthesis and of clonal growth in various cancer cell lines. All Pd(II) derivatives showed a noticeable activity very close to that of cisplatin, used as reference drug. Moreover, they showed significantly reduced cross-resistance to cisplatin in a pair of cell lines (2008/C13*) with known acquired cisplatin resistance mechanisms
Synthesis, characterization and cytotoxic activity of substituted benzyl iminoether Pt(II) complexes of the type cis- and trans-[PtCl2{E-N(H)=C(OMe)CH2-C6H4-p-R}(2)] (R = Me, OMe, F). X-ray structure of trans-[PtCl2{E-N(H)=C(OMe)CH2-C6H4-p-F}(2)]
No full textNew substituted benzyl iminoether derivatives of the type cis- and trans-[PtCl2{E-N(H)=C(OMe)CH2-C6H4-p-R}(2)] (R = Me (1a, 2a), OMe (3a, 4a), F (5a, 6a)) have been synthesized and characterized by elemental analyses, FT-IR spectroscopy and NMR techniques. The iminoether ligands are in the E configuration, which is stable in solution and in the solid state, as confirmed by the H-1 NMR data. Complex trans-[PtCl2{E-N(H)=C(OMe)CH2-C6H4-p-F}(2)] (6a) was also characterized by an X-ray diffraction study. Complexes 1 a-6a have been tested against a panel of human tumor cell lines in order to evaluate their cytotoxic activity. cis-Isomers were significant more potent than the corresponding trans-isomers against all tumor cell lines tested; moreover, complexes la and 5a showed IC50 values from about 2-fold to 6-fold lower than those exhibited by cisplatin, used as reference platinum anticancer drug
Characterization studies of Pt(II) and Pd(II) complexes of biological interest with N and S donors
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