Summary
The aim of the project was to synthesise and characterise new anticancer Cu(II) based complexes which can selectively accumulate in cancer cells.
To reach the selectivity for cancer cells some “estrogens like” compound were attached in the coordination sphere of the complexes. It is well known that cancer cells show overexpression of estrogen receptors in the cell membrane with respect the normal cells. The bioconjugation of this kind of estrogen to the metal can definitively be important to increase the accumulation of the drug in cancer cells.
Six new complexes have been synthesised and fully characterised. Biological assays have been performed (DNA binding, DNA cleavage) with very high promising activity.
The complexes have been characterised with Elemental Analyses, Mass Spectrometry and
Cyclic Voltammetry. The six complexes contain two different kind of estrogens: testosterone
(Complexes 1 , 3 and 5 ) and Estradiol ( 3 , 4 and 6 ). The estrogens have been attached through an alkynyl linker to the phenanthroline (Complexes 1 , 2 , 5 and 6 ) or to the necuproine ( 3 and
4 ). Furthermore, complexes 5 and 6 present another phenanthroline as ancillary ligand while comples 1 4 have halogen ligands which complete the coordination sphere around the Cu(II) centre.
Preliminary Biological assays show very interesting DNA binding of the complexes. The most active complexes are 5 and 6 ; the presence of the planar phen as ancillary ligand improves the intercalation properties of these two complexes and the binding constant for
Calf thymus DNA is five times higher with respect the other complexes. The worst complexes are 3 and 4 with necuproine instead of phenanthroline. The presence of neocuproine which is more sterically hindered (two methyl groups in position 2 and 9 of the phen) decreases the DNA intercalation properties of the complexes.

The DNA binding has been evaluated on five different kind of DNA (ct DNA, Salmon
Testes, ML (Micrococcus Latteus) DNA, Poly [d(A-T)
2
] and poly[d(G-C)
2
] using different techniques such as competition studies, DNA fluorescence quenching by ethidium bromide and
Hoechst 33258, DNA melting analyses and viscosity.
DNA cleavage properties have been evaluated through gel electrophoresis. Complexes 5 and
6 can cleave the DNA at low

M concentration while complexes 3 and 4 are the less active or show no activity.
Cytotoxic analyses on several cancer cell lines which show or do not show overexperession of the estrogen receptors are currently being carried out.
There is a general trend for all the complexes, with number 5 and 6 being the more active in terms of both DNA binding and cleavage and 3 and 4 being the worst. 1 and 2 show intermediate properties but closer to complexes 5 and 6 . Indeed the presence of necuproine is a big obstacle for the biological activity of the complexes.