Rh2(CF3CONH) 4: The First Biological Assays of a Rhodium (II) Amidate

Abstract

The rhodium (II) complexes Rh2(tfa)4.2(tfac) and Rh2(tfacam) 4 (tfacam CF3CONH-,tfa CF3COO-, tfac CF3CONH2) were synthesized and characterized b) microanalysis and electronic and vibrational spectroscopies. Rhz(tfacam)4 was tested both in vitro (U937 and K562 human leukemia cells and Ehrlich ascitic tumor cells) and in vivo for cytostatic activity and lethal dose determination, respectively. This is the first rhodium tetra-amidate to have its biological activity evaluated. The LDs0 value for Rh2(tfacam)4 is of the same order as that of cisplatin, and it was verified that the rhodium complex usually needs lower doses than cisplatin to promote the same inhibitory effects.

Effects of human serun albumin in some biological properties of rhodium(II) complexes

“…4 ] has been elected to in vivo studies to give continuity to our previous research on the antitumoral action of rhodium(II) amidates 29,34 . These results, together with the above considerations relating to the affinity of the rhodium complexes with HSA and/or intact cells, indicate that albumin can be a drug reservoir for [Rh 2 (tfc) 4 ], and probably for the other rhodium complexes as well, by means of capturing it in the bloodstream after injection and transferring it slowly to the tumor cell by passive diffusion.…”

Amidate-Ligated Complexes of Rhodium(I): A Showcase of Coordination Flexibility

“…In particular, these complexes have found application in several areas of research, including materials, 1 medicinal, 2 4 Our interest in amidate ligands stems from their inherent hemilability, which offers distinct and variable coordination modes (Chart 1), e.g., κ 1 -O or -N, κ 2 -N,O, or bridging (μ 2 -N,O); which mode is preferred depends on the steric and electronic requirements of a given metal center. Unlike monodentate ligands, the use of such heterofunctional bidentate ligands allows for access to metal coordinative unsaturation by way of a κ 1 -E (E = O, N) binding mode, for example.…”

Interactions of Metal—Metal‐Bonded Antitumor Active Complexes with DNA Fragments and DNA

“…8,10,11 The compounds Rh 2 (µ-O 2 CCF 3 ) 4 (Chart 1, structure a) and Rh 2 (µ-HNCOCF 3 ) 4 (Chart 1, structure b) have been reported to significantly increase the survival rate of mice bearing Ehrlich ascites cells and have LD 50 values on the same order as that of cisplatin. 19,20 The most active member of the methoxyphenylphosphine series is the oxygen-metalated complex Rh 2 (µ-O 2 CCH 3 ) 3 [µ-(o-OC 6 H 4 )P-(o-OMeC 6 H 4 ) 2 ](HOCCH 3 ) (Chart 1, structure c), which exhibits higher antitumor activity than cisplatin. 21 Moreover, cationic compounds of general formulae [Rh 2 -(µ-O 2 CCH 3 ) 2 (N-N) 2 (H 2 O) 2 ] 2+ (N-N ) 2,2′-bipyridine (bpy) or 1,10-phenanthroline) (Chart 1, structure d) exhibit anticancer activity against human oral carcinoma KB cell lines comparable to Rh 2 (µ-O 2 CCH 3 ) 4 .…”