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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

The role of ancillary ligand substituents in the biological activity of triruthenium-NO complexes

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Neves da Silva, Camila Fontes [1] ; Possato, Bruna [1] ; Franco, Lilian Pereira [1] ; Barbosa Ramos, Loyanne Carla [2] ; Nikolaou, Sofia [1]
Total Authors: 5
[1] Univ Sao Paulo, Fac Filosofia Ciencias & Letras Ribeirao Preto, Dept Quim, Av Bandeirantes 3900, BR-14040901 Ribeirao Preto, SP - Brazil
[2] Univ Sao Paulo, Fac Ciencias Farmaceut Ribeirao Preto, Av Bandeirantes 3900, BR-14040901 Ribeirao Preto, SP - Brazil
Total Affiliations: 2
Document type: Journal article
Source: Journal of Inorganic Biochemistry; v. 186, p. 197-205, SEP 2018.
Web of Science Citations: 0

Two novel triruthenium clusters, {[}Ru-3(mu(3)-O)(mu-OOCCH3)(6)(NO)L-2]PF6 (L = 4-acetylpyridine, 1, or 4-tert-butylpyridine, 2) release NO. Their spectroscopic and electrochemical characterization confirmed their structure. These complexes efficiently deliver NO in solution under irradiation at lambda(irrad) = 377 nm and/or through chemical reduction with ascorbic acid. Clusters 1 and 2 elicit vasodilation and, at concentrations of 10(-5) M, can relax up to 100% of pre-contracted rat aorta. Complex 2 is more cytotoxic to murine melanoma B16F10 cells than complex 1: at 50 times lower concentration than complex 1, complex 2 decreases cell viability to 50% in the dark or under irradiation with visible light (lambda(irrad) = 527 nm). The higher cytotoxicity of complex 2 can be assigned to its larger hydrophobicity, promoted by the methylated tert-butylpyridine ancillary ligand in its structure. Investigation into human serum albumin (HSA) fluorescence quenching by clusters 1 or 2 revealed that complex 2 quenches HSA luminescence with a very high Stern-Vomer constant (K-SV = 9.49 x 10(7) M-1 at T = 298?K) and suggested that the nature of the interaction between complex 2 and HSA is hydrophobic (Delta H = 80.81 kJ/mol and Delta S = 334.71?J/K?mol). HSA lifetime and circular dichroism data pointed to a static quenching mechanism for both complexes. Together, our results show that a hydrophobic substituent in the cluster ancillary ligand improves NO release ability, cytotoxicity, and interaction with a bio-target. (AU)

FAPESP's process: 14/25561-8 - Trinuclear ruthenium carboxylates with functional ligands CO, NO and intercalators: chemical study and interactions with biomolecules target
Grantee:Camila Fontes Neves da Silva
Support Opportunities: Scholarships in Brazil - Doctorate
FAPESP's process: 15/20302-7 - Using non-steroidal antiinflammatory drugs, azanaphtalenes and phenazines as ligands for the development of bi- and trinuclear rutenium carboxylates with potential antialergic, tumoricide and tripanocide activities
Grantee:Sofia Nikolaou
Support Opportunities: Regular Research Grants