THE PHOSPHODIESTER GROUPS OF D(TPT)(-) AND D(TPG)(-) COORDINATE TO PLATINUM(II) IN N,N-DIMETHYLFORMAMIDE

The propensity of the phosphodiester group to bind platinum(II) was in vestigated by examining the reactions of the dinucleotide salts NH4{d( TpT)} and NH4{d(TpG)} with the complexes [Pt(NO3)(NH3)(3)]NO3 (1) and cis-[Pt(NO3)(2)-(NH3)(2)] (2) in N,N-dimethylformamide. d(TpT)(-) coor dinates to the platinum atom of both 1 and 2 through either of the two nonbridging phosphoryl oxygen atoms, as revealed by P-31 NMR spectros copy. Conversely, d(TpG)(-) binds to 1 through the guanine N7 atom. Wi th 2, d(TpG)(-) forms monodentate adducts bound to N7(G), as well as t wo distinct macrochelates, in which N7(G) and one of the nonbridging p hosphoryl oxygens are crosslinked by platinum, We suggest that guanine -phosphoryl macrochelate complexes play a role as intermediates in rea rrangements of platinum monoadducts formed with DNA.