INOR 626 |
| The fac-[Re(I)(CO)3(H2O)3]+ cation is the putative reactive species binding to DNA, the likely biomolecular target responsible for anticancer activity of related Re(I) compounds. In dilute aqueous solution 5'-guanosine monophosphate (5'-GMP) added to fac-[Re(I)(CO)3(H2O)3]+ slightly faster than 3'-guanosine monophosphate (3'-GMP) to form a 1:1 Re:GMP adduct. This adduct formed the 1:2 adduct faster for 3'-GMP than for 5'-GMP. We can also establish that 1:2 3'-GMP adducts are thermodynamically more favored than 1:2 5'-GMP adducts. A ternary mixture experiment (5'-GMP:3'-GMP:Re) excluded the formation of 2:2 cyclic dimers or macrochelates; however, the data revealed the formation of two mixed 5'-GMP/3'-GMP bis adducts in a 60:40 ratio. At equilibrium, the mixed adducts are less stable than the 3'-GMP bis adduct but more stable than the 5'-GMP bis adduct. The phosphate group cannot approach the metal for 3'-GMP; the greater stability for the 3'-GMP adducts probably reflects more favorable N1H-phosphate interligand interactions for 3'-GMP vs. 5'-GMP. |
|
Bioinorganic Chemistry
7:00 PM-10:00 PM, Tuesday, 12 September 2006 Moscone Center -- Hall D, Poster
Sci-Mix
Division of Inorganic Chemistry |