Kinetic and mechanistic studies on reactions of diruthenium(II,III) with biologically relevant reducing agents

Author(s)

Silva Ribeiro Santos, Rodrigo Luis ^{[1, 2]} ; van Eldik, Rudi ^[2] ; Silva, Denise de Oliveira ^[1]

Affiliation

^[1] Univ Sao Paulo, Inst Quim, Dept Quim Fundamental, BR-05508000 Sao Paulo - Brazil

^[2] Univ Erlangen Nurnberg, Dept Chem & Pharm, D-91058 Erlangen - Germany

• Document type: Journal article
• Source: DALTON TRANSACTIONS; v. 42, n. 48, p. 16796-16805, 2013.
• Web of Science Citations: 11

Abstract

Diruthenium(II,III)-tetracarboxylates have shown promising anticancer properties as metallotherapeutics. On the basis of the role that bio-reducing agents may play on the mode of action of ruthenium-based anticancer drugs, we performed detailed kinetic studies on the reaction of ascorbic acid and glutathione with the {[}Ru-2(RCOO)(4)](+) paddlewheel framework by using the non-drug, diaqua complex ion {[}Ru-2(CH3COO)(4)(H2O)(2)](+). In the presence of the reducing agents, the diaqua-Ru-2 species first undergo a ligand substitution reaction by which the axially-coordinated water is displaced by the reducing agent. In both cases, this reaction is followed by an intra-molecular electron transfer process during which the metal-metal center is reduced from Ru-2(5+) to Ru-2(4+) and the reducing agent is oxidized. Product analyses were performed with the application of ESI-MS and H-1-NMR techniques. Rate and activation parameters are reported for the different reaction steps. (AU)

• FAPESP's process: 05/60596-8 - Complex species with potential for application in bio-organics, catalysis, pharmacology and environmental chemistry: conception, preparation, characterization and reactivity
• Grantee: Ana Maria da Costa Ferreira
• Support Opportunities: Research Projects - Thematic Grants
• FAPESP's process: 11/06592-1 - Anti-inflammatory and antitumor metallotherapeutic drugs: reactivity, properties and interactions with biocompatible hosts
• Grantee: Denise de Oliveira Silva
• Support Opportunities: Regular Research Grants