Reactivity studies of anticancer active dirhodium complexes with 2-aminothiophenol.

The study of biologically active inorganic compounds has led to the development of several important chemotherapeutic drugs in the past few decades, the most notable example of which is cis-[PtCl2(NH3)2] (cis-DDP).1 In addition to compounds of platinum, many other transition metal complexes have been found to exhibit considerable antineoplastic activities, including those of general formulae Rh2(μ-O2CR)4 and [Rh2(μ-O2CR)2(N-N)2L2]X2 (N-N ) 2,2′-bipyridine and 1,10-phenanthroline; L ) solvent molecules; X ) Cl, Br).2,3 The latter family of compounds is of particular interest due to their improved anticancer activity against different tumor lines (e.g., human oral carcinoma KB) as compared to their Rh2(μ-O2CR)4L2 counterparts (L ) solvent molucules).3 A perusal of the literature reveals a scarcity of information vis-à-vis the cellular metabolism of these dirhodium compounds, but it is known from preliminary studies that DNA replication is significantly inhibited and that protein synthesis is slightly affected.4