BINARY AND TERNARY COMPLEXES OF PLATINUM(II) WITH THE DIPEPTIDE ESTERS GLY-GLYOET, GLY-ALAOME, GLY-2-ABAOME, GLY-NVALOME, GLY-NLEUOME, AND THE NUCLEOSIDES GUO (GUANOSINE) AND CYD (CYTIDINE)

摘要

The binary complexes of formulae cis-(dipeptide)(2)PtCl2 and the ternary complexes of formulae cis-[(guo)(2)Pt(dipeptide)(2)]Cl-2 and cis[(cyd)(2) Pt(dipeptide)(2)]Cl-2, with guo = guanosine, cyd = cytidine, dipeptide = glyglyOEt, gly-1-alaOMe, gly-2-1-abaOMe, gly-1-nvalOMe, gly-1-nleuOMe, were isolated and characterized by elemental analysis, conductivity measurements, H-1, C-13 NMR and IR spectroscopy. The binary complexes were obtained by the reaction of K2PtCl4 with the dipeptide esters and the ternary ones by further reactions of the binary complexes with the corresponding nucleosides. The dipeptides are monocoordinated through their amino groups with Pt2+. Ligand-ligand hydrophobic interactions were observed to decrease with distance from the bonding sites. The percentages of the E-3 and anti conformations of the nucleosides increase, while the gg ones decrease in the complexes. Finally, the h conformers around the -CH alpha-CH beta R- bonds of the peptides decrease on passing to the ternary from the binary system and increase with longer aliphatic chains. [References: 45]