Anticancer Activity of Monodentate Phosphines and Their Complexes with Other

2 Anticancer Activity of Monodentate Phosphines and Their Complexes with Other Metals 

The National Cancer Institute (NCI, Bethesda) have tested over 150 phosphines (PR3) for anticancer activity. With the exception of a number of diphosphine ligands (which we discuss in detail in Sect. 3.4.1), none of the tested tertiary phosphine ligands exhibited more than at best marginal activity (PPh2Me). However, it is probable that many of the phosphines would have been rapidly oxidised in vivo (or even in the testing medium), and so the data may actually refer to phosphine-oxides. Coordination to Au(I) may protect the ligands from unfavourable oxidation. 

However, it is inactive in many other tumour systems including L1210 leukaemia (NCI data). Pt(0) like Au(I) is a 5d metal ion. If the antitumour activity of the Au(I) phosphine complexes is attributable to the presence of the phosphine ligands, then the kinetic lability of the complexes is likely to be crucial, so that the ligand can be released at the target site. 

As discussed above, the cytotoxicity of auranofin to cultured tumour cells in vitro was significantly reduced when the culture media contained serum proteins This suggested to us that in order to obtain a broader spectrum of antitumour activity it would be 

Also inactive in ip. B16 melanoma and ip. P388 leukaemia (in mice)  

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