38780-35-7Relevant academic research and scientific papers
Molecular interaction fields vs. quantum-mechanical-based descriptors in the modelling of lipophilicity of platinum(iv) complexes
Ermondi, Giuseppe,Caron, Giulia,Ravera, Mauro,Gabano, Elisabetta,Bianco, Sabrina,Platts, James A.,Osella, Domenico
supporting information, p. 3482 - 3489 (2013/03/28)
We report QSAR calculations using VolSurf descriptors to model the lipophilicity of 53 Pt(iv) complexes with a diverse range of axial and equatorial ligands. Lipophilicity is measured using an efficient HPLC method. Previous models based on a subset of these data are shown to be inadequate, due to incompatibility of whole molecule descriptors between carboxylato and hydroxido ligands. Instead, the interaction surfaces of complexes with various probes are used as independent descriptors. Partial least squares modelling using three latent variables results in an accurate (R2 = 0.92) and robust model (Q2 = 0.87) of lipophilicity, that moreover highlights the importance of size and hydrophobicity terms and the modest relevance of hydrogen bonding.
Conformational isomerism of trans-[Pt(NH2C6H 11)2I2] and the classical Wernerian chemistry of [Pt(NH2C6H11)4]X2 (X = Cl, Br, I)
Johnstone, Timothy C.,Lippard, Stephen J.
, p. 565 - 575 (2013/06/27)
X-ray crystallographic analysis of the compound trans-[Pt(NH 2C6H11)2I2] revealed the presence of two distinct conformers within one crystal lattice. This compound was studied by variable temperature
Study of Pt(II)-cyclic amines complexes of the types cis- and trans-Pt(amine)2I2 and cis- and trans-Pt(amine) 2(NO3)2 and their aqueous products
Rochon, Fernande D.,Buculei, Viorel
, p. 2040 - 2056 (2008/10/09)
Complexes of the types cis- and trans-Pt(amine)2I2 containing cyclic amines were synthesized and studied mainly by IR and multinuclear NMR spectroscopies. The compounds were converted to cis- and trans-Pt(amine)2(NO3)2, which were also investigated. The hydrolysis and the aquation reactions of the latter compounds were then studied in D2O in different conditions of pH. In acidic medium, the aqueous product is [Pt(amine)2(D2O) 2]2+ and for a few amines, [Pt(amine)2(D 2O)(NO3)]+ was detected. In basic pH, the main product is Pt(amine)2(OD)2 and Pt(amine) 2(OD)(NO3) was detected for several compounds. In neutral pH, the cis isomers form between two and four species in fresh solutions. The most shielded species in 195Pt NMR is the monoaqua-monohydroxo complex cis-[Pt(amine)2(D2O)(OD)]+ and the less shielded compound is the dihydroxo-bridged dimer [Pt(amine)2(μ- OD)2Pt(amine)2]2+, which were observed for all the compounds. For a few amines, the monohydroxo-bridged dimer [Pt(D 2O)(amine)2(μ-OD)Pt(OD)(amine)2] 2+ was detected and for cyclohexylamine, a fourth signal was assigned to a cyclic hydroxo-bridged trimer [(Pt(amine)2(μ-OD)) 3]3+. 195Pt NMR spectroscopy has shown that the concentration of the monomer decreases with time, while the concentration of the dimers increases. Only one product was observed for the trans isomers in neutral pH. The signal was assigned to the monoaqua-monohydroxo species trans-[Pt(amine)2(D2O)(OD)]+. The 13C and 1H NMR spectra of most of the complexes were measured. All the coupling constants 2,3J(195Pt- 1H) and 2,3J(195Pt-13C) are larger in the cis compounds than in the trans isomers.
Dichlorobis(cycloalkylamine)platinum(II) Complexes. Structure Activity Relationship on the Human MDA-MB-231 Breast Cancer Cell Line
Kritzenberger, J.,Bernhardt, G.,Gust, R.,Pistor, P.,Schoenenberger, H.,Yersin, H.
, p. 587 - 605 (2007/10/02)
The syntheses of dichlorobis(cycloalkylamine)platinum(II) complexes with cis and trans cycloalkylamine ligands are described.The distinction between cis and trans isomers was achieved by (1)H-NMR spectroscopy.The antitumor activity was determined on the cell proliferation of the human MDA-MB-231 breast cancer cell line during long-term drug exposure.The complexes with small cycloalkylamine ligands (3-6) were inferior, those with large cycloalkylamine ligands were comparable (7) or superior (8) to cisplatin.Surprisingly, the cis/trans isomers 7/9 and 8/10 were equally active.All cycloalkylamine ligands were inactive.IR-spectroscopic studies showed that the size of the cycloalkylamine ring does not lead to significant differences in the Pt-Cl binding strength.Therefore it is assumed that the markedly stronger antitumor activity of the higher homologues, 7-10, is not the result of a faster reaction with binucleophiles such as DNA.A possible explanation of the high activity of 7-10 is the strong lipophilicity of the complexes.This assumption was confirmed by toxicity tests against confluent cultures. Key words: cis- and trans-Dichlorobis(cycloalkylamine)platinum(II) complexes; antitumor activity; MDA-MB-231 breast cancer cell line.
Effects of Geometric Configuration and Steric Hindrance on Rates and Mechanisms of Oxidation of Diaminedichloroplatinum(II) Complexes by Tetrachloroaurate(III) Ions
Peloso, Arnaldo
, p. 1285 - 1290 (2007/10/02)
The oxidation reactions of trans- and/or cis- by - in the presence of Cl have been kinetically investigated in acetonitrile (R=H,Me,Et,Prn,Pri,Bun,Bui,Bus,But,CH2But,CH2Ph, or cyclo-C6H11).The rate law for the oxidation of the trans complexes consists mainly of a third-order rate term, kc->->, whereas an additiona rate term, ka->->/(1+kb->), operates in the case of the cis complexes.A reaction scheme is proposed.The oxidation rates of both cis and trans complexes appear to be reduced by increasing the steric hindrance of the amine, cis complexes being more sensitive towards changes of steric hindrance than trans analogues.Approximate linear relationships correlate the reactivities (log k) of both cis and trans complexes with an amine steric hindrance parameter.
