Characterisation and In Vitro Cytotoxicity of Triorganophosphinegold(I) 2-Mercaptobenzoate Complexes

The preparation and full NMR ((1)H, (13)C and (31)P) characterisation of three [R(3)PAu(2mba)] complexes, Where R = Et, Ph and Cy, and 2mba is the anion derived from 2-mercaptobenzoic acid is reported. An interesting solvent dependence in the (1)H spectra is rationalised in terms of competing intra- and inter-molecular hydrogen bonding. An X-ray analysis of the [Ph(3) PAu(2mba)] species reveals a linear P—Au—S arrangement and association in the lattice via the familar carboxylic acid dimer motif. The in Vitro cytotoxicity against seven human tumout lines is also described. The complexes display moderate to very high activity. Particularly noteworthy is their greater activity against the H226 cell line (non-small cell lung cancer) compared with that displayed by a range of cytotoxic drugs.