Cytotoxic half-sandwich rhodium(III) complexes: Polypyridyl ligand influence on their DNA binding properties and cellular uptake

Comparative solution equilibrium studies on pentamethylcyclopentadienyl rhodium complexes of 2,2ʹ-bipyridine and ethylenediamine and their interaction with human serum albumin

“…Whereas RhCp* complexes formed with 2-picolinic acid (pic) [12] and 3-hydroxy(thio)pyrones derivatized by morpholine, piperidine or N-methylpyrazine moieties [13] exhibited only poor or no bioactivity. Promising in vitro antiproliferative activities have been reported for the RhCp* complexes of (N,N) polypyridyl (pp) ligands by Sheldrick et al [14][15][16][17] possessing IC 50 values in the low micromolar range. However, the RhCp* complexes of the simplest bidentate alkylamino and aromatic N-donor ligands, namely ethylenediamine (en) and 2,2'-bipyridine (bpy) did not show significant cytotoxicity (IC 50 >100 μM measured in MCF-7 and HT-29 cells) [17].…”

“…Promising in vitro antiproliferative activities have been reported for the RhCp* complexes of (N,N) polypyridyl (pp) ligands by Sheldrick et al [14][15][16][17] possessing IC 50 values in the low micromolar range. However, the RhCp* complexes of the simplest bidentate alkylamino and aromatic N-donor ligands, namely ethylenediamine (en) and 2,2'-bipyridine (bpy) did not show significant cytotoxicity (IC 50 >100 μM measured in MCF-7 and HT-29 cells) [17]. On the contrary the antiproliferative activity of [Ru(II)( 6 -p-cymene)(en)Cl]PF 6 and [Ru(II)( 6 -biphenyl)(en)Cl]PF 6 complexes developed in the laboratory of Sadler is comparable to carboplatin (IC 50 6-9 μM measured in A2780 cells) [18].…”

“…No correlation was found for the aquated IrCp* complexes of 1,10-phenanthroline (phen), bpy and en ligands as well [57]. On the other hand, complexes of bpy, en and pic show fairly poor or no activity against various human cancer cell lines [12,17] [11,12].…”

Comparative equilibrium and structural studies of new pentamethylcyclopentadienyl rhodium complexes bearing (O,N) donor bidentate ligands

“…Recently more and more studies have focused on their antitumor activity [9,[11][12][13][14][15]. Among the first reports dealing with the anticancer properties of Rh(III) compounds were those investigating the salt reported by Sheldrick and co-workers [18][19][20][21]. Another very interesting concept involving dirhodium(II,II) complexes that preferentially bind to the nucleobases of RNA and DNA, thereby disrupting protein synthesis and cell proliferation, has been developed by Dunbar and co-workers [22][23][24].…”

“…[28] and the simple bidentate alkylamino and aromatic N-donor ligands, namely ethylenediamine and 2,2ʹ-bipyridine (bpy), were examined and revealed negligible cytotoxicity [21].…”