The silver(I) complex [Ag(eppe)2]NO3
(eppe = Et2PCH2CH2PPh2) is shown by X-ray
crystallography to be tetrahedral with Ag - PEt2
and Ag - P Ph2
bond lengths of 2.482 and 2.518 Å,
respectively. The complex is selectively antimitochondrial and inhibits the growth of a number of
yeast strains in non-fermentable media at concentrations as low as 2.5 μΜ
and induces the
mitochondrial mutation petite The effect is largely reversed by the presence of aspirin. The complex
is shown to be stable in the cell culture media and in the presence of glutathione, but readily reacts
with disulfides of oxidized glutathione and serum albumin. Surprisingly, neither [Au(eppe)2]Cl nor
[Au(dppe)2]Cl (dppe = Ph2PCH2CH2PPh2) showed any mitochondrial selectivity in the same
screening protocol.