The in vitro cytotoxicities of a number of gold(I), silver(I) and copper(I) complexes containing chiral
tertiary phosphine ligands have been examined against the mouse tumour cell lines P815
mastocytoma, B16 melanoma [gold(I) and silver(I) compounds] and P388 leukaemia [gold(I)
complexes only] with many of the complexes having IC50 values comparable to that of the
reference compounds cis-diamminedichloroplatinum(ll), cisplatin, and bis[1,2-bis(diphenylphosphino)
ethane]gold(I) iodide. The chiral tertiary phosphine ligands used in this study include
(R)-(2-aminophenyl)methylphenylphosphine; (R,R)-, (S,S)- and (R*,R*)-1,2-phenylenebis(methylphenylphosphine);
and (R,R)-, (S,S)- and (R*,R*)-bis{(2-diphenylphosphinoethyl)phenylphosphino}ethane. The in vitro cytotoxicities of gold(I) and silver(I) complexes containing the
optically active forms of the tetra(tertiary phosphine) have also been examined against the human
ovarian carcinoma cell lines 41M and CH1, and the cisplatin resistant 41McisR, CH1cisR and
SKOV-3 tumour models. IC50 values in the range 0.01 - 0.04 μM were determined for the most
active compounds, silver(I) complexes of the tetra(tertiary phosphine). Furthermore, the chirality of
the ligand appeared to have little effect on the overall activity of the complexes: similar IC50 data
were obtained for complexes of a particular metal ion with each of the stereoisomeric forms of a
specific ligand.
