Thermodynamics and kinetics of some tetra-.mu.-carboxylato-dirhodium(II) adduct formation reactions

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

“…This possibility has indeed been proposed 31 . In fact, one could consider that the overall affinity between rhodium(II) complexes and HSA results from two distinct phenomena: (a) axial coordination with His residues, and (b) hydrophobic interactions between the complex and the protein skeleton.…”

“…It was noticed that the stability of rhodium(II) complexes and His was correlated with the lipophilic nature of the metal compounds. Binding constants to the formation of adducts of the kind [Rh 2 (bridge) 4 ] (His) (bridge = ac, pr) were reported as 4.05 and 4.14, respectively, the difference being attributed to the lesser solvation and therefore the increased propionate binding to His 31 .…”

Inhibiting prolyl isomerase activity by hybrid organic–inorganic molecules containing rhodium(II) fragments

“…22,23 They bind not only thiol, thioether, and imidazole side chains, but also other weaker Lewis-bases such as the carboxylate side chain of glutamate. 24,25 We previously reported that methionine, glutamate, and histidine interact with the rhodium(II) center in a coil-coil heterodimer, stabilizing an otherwise weak supramolecular assembly. 26,27 From this precedent, rhodium(II) metallopeptides ligands for PDZ were designed that utilize coordination to a specific histidine residue (PDZ His301) to afford significantly tighter binding (40-80 fold).…”

Síntese e caracterização de carboxilatos de Rh(II) e seus adutos com metronidazol: ensaios biológicos com vistas à vtividade radiossensibilizadora de tumores

“…Posteriormente, estes mesmos autores, determinaram alguns parâmetros cinéticos e termodinâmicos de reações de formação de adutos de acetato, propionato e metoxiacetato com ligantes, 5'AMP, histidina, imidazol e piridina. Essas medidas foram feitas com a finalidade de determinar se a ordem de estabilidade: propionato > acetato> metoxiacetato, era mantida para uma variedade de ligantes, e observar se a velocidade de formação desses adutos também era maior para o aduto de propionato [141].…”

“…Para comprovar um possível efeito 1t receptor dos Iigantes, foram determinados parâmetros termodinâmicos do aduto de metoxiacetato com piridina, desde que este ligante apresentava um efeito 1t receptor maior do que a histidina, imidazol e 5'AMP [141]. Esperava-se, assim, que esse aduto resultasse mais estável ainda do que o complexo imidazólico, apesar de que este último apresentava maior basicidade no átomo de nitrogênio doador.…”