The first examples of platinum amine hydroxamate complexes: structures and biological activity

Two novel benzohydroxamate complexes of anticancer active Pt(II)-diamine moieties have been synthesised in which Pt-C bonds are present in the dinuclear structures. The complexes, [{Pt(en)}2(mu-bha)]ClO4·H2O (en = ethane-1,2-diamine) and [{Pt(R,R-chxn)}2(mu-bha)]NO3·2H2O (chxn = cyclohexane-1,2-diamine), have two platinum centres that are bridged through the bha ligand via(O,O) and (C,N) coordination modes, the latter mode occurring through deprotonation of the ortho carbon of the phenyl ring. The cytotoxicities of the complexes were tested against a panel of cell lines based on the A2780 ovarian cancer cell line and revealed that both dinuclear complexes were less active than their corresponding dichloro parent complexes. It is likely that they act in a similar manner to the parent complexes, but with the cytotoxicity mediated by factors influencing cellular uptake, such as the charge and lipophilicity of the compounds.