Ru/Fe bimetallic complexes: Synthesis, characterization, cytotoxicity and study of their interactions with DNA/HSA and human topoisomerase IB

Author(s)

Takarada, Jessica E. ^[1] ; Guedes, Adriana P. M. ^[2] ; Correa, Rodrigo S. ^[2] ; Silveira-Lacerda, Elisangela de P. ^[3] ; Castelli, Silvia ^[1] ; Iacovelli, Federico ^[1] ; Deflon, Victor Marcelo ^[4] ; Batista, Alzir Azevedo ^[2] ; Desideri, Alessandro ^[1]

Affiliation

^[1] Univ Roma Tor Vergata, Dept Biol, Via Ric Sci, I-00133 Rome - Italy

^[2] Univ Fed Sao Carlos, Dept Chem, CP 676, BR-13565905 Sao Carlos, SP - Brazil

^[3] Univ Fed Goias, Inst Biol Sci, Lab Mol Genet & Cytogenet, Goiania, Go - Brazil

^[4] Univ Sao Paulo, Inst Quim Sao Carlos, CP 780, BR-13560970 Sao Carlos, SP - Brazil

• Document type: Journal article
• Source: Archives of Biochemistry and Biophysics; v. 636, p. 28-41, DEC 15 2017.
• Web of Science Citations: 8

Abstract

Three ruthenium/iron-based compounds, 1: {[}Ru(MIm)(bipy)(dppf)]PF6 (MIm = 2-mercapto-1-methylimidazole anion), 2: {[}RuCl(Im)(bipy)(dppf)]PF6 (Im = imidazole), and 3: {[}Ru(tzdt)(bipy)(dppf)]PF6 (tzdt = 1,3-thiazolidine-2-thione anion) (dppf = 1,1 `-bis(diphenylphosphine)ferrocene and bipy = 2,2 `-bipyridine), were synthesized, and characterized by elemental analyses, conductivity, UV/Vis, IR, H-1, C-13 and P-31[1H] NMR spectroscopies, and by electrochemical technique. The complex 3 was also characterized by single-crystal X-ray. The three ruthenium(II) complexes show cytotoxicity against DU-145 (prostate carcinoma cells) and A549 (lung carcinoma cells) tumor cells. The free ligands do not exhibit any cytotoxic activity, such as evident by the IC50 values higher than 200 mu M. UV/Vis and viscosity experiments showed that the complexes interact weakly with the DNA molecule, via electrostatic forces. The interaction of the complexes 1-3 with the HSA is moderate, with K-b values in range of 10(5)-10(7) M-1, presenting a static mechanism of interaction stabilized by hydrophobic. Complexes 2 and 3 showed high affinity for the FA7 HSA site as evidenced by fluorescence spectroscopy and molecular docking. Complexes 1-3 were tested as potential human Topoisomerase IB inhibitors by analysing the different steps of the enzyme catalytic cycle. The results indicate that all compounds efficiently inhibit the DNA relaxation and the cleavage reaction, in which the effect increases upon pre-incubation. Complexes 1 and 2 are also able to slow down the religation reaction. (AU)

• FAPESP's process: 14/10516-7 - Search for ruthenium (II) complexes, with chemotherapeutic properties: evaluation of possible sinergistic effects and possible action mechanism
• Grantee: Alzir Azevedo Batista
• Support Opportunities: Regular Research Grants